ALBERT

Notes: . Norlevinea n. g. is established for microsporidia in which a uninucleate meront changes into a sporont by secreting a thin, membranous, sporontogcnetic and fragile sporophorous vesicle (pansporoblast membrane) in which four uninucleate sporoblasts are formed. In contrast to the genus Gurleya, the sporoblasts and later the spores are permanently joined into doublets, being laterally cemented by an electron-dense substance structurally identical to and continuous with the exospore layer. The polar filament is of the anisofilar type. The type species is Norlevinea daphniae (Weiser, 1947) n. comb., a parasite of the ovaries of Daphnia longispina occurring in several carp ponds in Czechoslovakia.

Notes: . The microsporidian parasite known as Nosema helminthorum Moniez, 1887, parasitic in the tapeworm Moniezia expansa (Rudolphi, 1810), has been shown by electron microscopy to have two cycles of development, one with isolated nuclei, the other with paired nuclei (diplokarya). Both merogony and sporogony of the two separate sequences take place in direct contact with the host cell cytoplasm and ultimately give rise to unikaryotic and diplokaryotic sporoblasts. Sporogony is disporoblastic. The nuclear condition of the spores was not seen. The sequences, corresponding to those of the genera Unikaryon and Nosema, may be part of a single dimorphic life cycle and, if so, the species will have to be transferred to a new genus.

Notes: . Sarcocystis falcatula Stiles, 1893 is re-described. Intermediate hosts of the parasite which was earlier described as Sarcocystis debonei Vogelsang, 1929 are species of passeriform, psittaciform, and columbiform birds. In these birds, muscle zoites are 6.88 × 2.19 (4.8-8.4 × 1.2-3.6) μm and are enclosed in a cyst wall with regular protrusions, 1-5 μm long. The convoluted primary wall has multiple thin areas in the osmiophilic layer. Microtubules originate in the ground substance and extend to the tips of the protrusions. The only known definitive host is the opossum, Didelphis virginiana; rats, cats, a dog, and a ferret could not be infected from muscle cysts. Sporocysts from opossums infected from five different infected avian sources measure 11.2 × 7.4 (9.6−12.0 × 6.0-8.4)μm.

Notes: . Descriptions are given of two new species of Hepatozoon Miller, 1908 found in the pygmy squirrel, Idiurus macrotis, in the Ivory Coast. Gamonts of both are parasites of monocytes.The size and shape of the gamonts of one, H. normani n. sp., are similar to those of a number of gamonts of other species of rodent hemogregarines and the separate identity of the parasite is based on the host restriction of mammalian hemogregarines. The gamonts of the other species, H. dolichomorphon n. sp., are remarkably long and slender and are unlike those of any other known hemogregarine of mammals. Schizonts of this species were found in a smear prepared from heart blood.

Notes: . The presence of nonvariant antigens (NVAs) limited to bloodstream forms of Trypanosoma brucei brucei and Trypanosoma brucei rhodesiense was demonstrated for the first time by immunodiffusion and Immunoelectrophoresis. Noncloned and cloned populations were employed in preparation of polyclonal antisera in rabbits and of antigens to be used in the immunologic reactions. The NVAs could be shown best in systems in which hyperimmune rabbit sera (adsorbed with procyclic forms to eliminate antibodies against antigens common to bloodstream form and procyclic stages) were reacted with trypanosomes characterized by heterologous variant-specific antigens (VSAs).The NVAs demonstrated in this study are very likely different from the common parts of VSAs. As has been suggested by experiments with living trypanosomes, at least a part of the NVAs appears to be located on the surface of the bloodstream forms. In these experiments involving the quantitative indirect fluorescent antibody test, the amount of fluorescence recorded for the heterologous system, i.e. ETat 5 trypanosomes incubated with anti-AmTat 1.1 serum, equalled ∼3.0% of the fluorescence emitted by the AmTat 1.1 bloodstream forms treated with their homologous antiserum. Evidently, only small amounts of NVAs are present on the surfaces of T. brucei bloodstream forms.In addition to the NVAs, the electrophoresis results suggested the presence of antigenic differences between procyclic stages belonging to different T. brucei stocks.

Notes: . Late schizonts from continuous cultures of P. falciparum were concentrated over Percoll, inoculated to various experimental media at the rate of about 20 × 106 per 0.5 ml of medium, and incubated in a candle jar at 37° for 1 day. Controls in standard culture medium showed a heavy invasion with young rings in the previously uninfected red cells introduced with the inoculum of schizonts. In a medium of high potassium content containing a 33% extract of human erythrocytes, this invasion was inhibited and many free merozoites were present. If, however, this same medium was supplemented with both ATP, as the dipotassium salt at 1.6 mM, and sodium pyruvate at 3.6 mM, there appeared large numbers of extracellular forms resembling young rings. Examination of these by electron microscopy shows that they are indeed merozoites that have begun to differentiate extracellularly. This suggests that the trigger for differentiation of merozoites may not depend on the process of entry into a red cell but rather on specific factors within the red cell.

Notes: . Opossums (Didelphis marsupialis), act as intermediate hosts for Besnoitia darlingi and could be infected orally with sporozoites (oocysts) and bradyzoites (tissue cysts), or intraperitoneally (i.p.) with tachyzoites. Infections could presumably be transmitted through cannibalism. Cats (Felis catus), the definitive host, could be infected only with bradyzoites but not sporozoites. Oocysts shed by cats measure about 12 × 12 μm, resemble similarly sized oocysts of Toxoplasma gondii and Hammondia hammondi, and must be differentiated by the appearance of tissue cysts after experimental infection of intermediate hosts. Cats did not form tissue cysts of B. darlingi. Tachyzoites from the related B. jellisoni could be used in the Sabin-Feldman dye test to determine the development of antibody to B. darlingi in opossums after infection.

Notes: Developmental stages of Caryospora simplex were found in connective tissue of the cheek, tongue, and nose of Swiss-Webster and C57 BL/6 mice (Mus musculus) from 8 through 70 days after oral inoculation with 50,000 or 250,000 oocysts, or 60,000 free sporocysts of the same species obtained from an Ottoman viper, Vipera xanthina xanthina. The earliest developmental stages were seen on day 8 post-inoculation (PI) and consisted of two types of meronts and gamonts (undifferentiated sexual stages). Gamonts, microgametocytes, macrogametes, and unsporulated oocysts were found on days 10 and 12 PI. Fully sporulated, thin-walled oocysts containing eight sporozoites surrounded by a thin sporocyst membrane were first seen 12 days PI. Monozoic cysts (caryocysts) were first seen 12 days PI and appeared fully viable throughout the duration of the study, 70 days PI. Four mice injected intra-peritoneally with 150,000 free sporozoites and killed 12 days PI contained unsporulated and sporulated oocysts in connective tissues of the cheek, tongue, and nose, suggesting that sporozoites may be carried to the site of infection via the lymphatic/circulatory system. Four cotton rats, Sigmodon hispidus, inoculated orally with 250,000 oocysts all had unsporulated and sporulated oocysts of C. simplex in connective tissue of the cheek, tongue, and nose when killed on day 12 PI, indicating extraintestinal development in the secondary host is not species specific. This is the first report of a heteroxenous coccidium with both asexual and sexual development in the primary (predator) and secondary (prey) hosts.

Notes: Trypanosoma lucknowi n. sp. was isolated in culture from one of 126 Macaca mulatta originating from the vicinity of Lucknow, Uttar Pradesh, India. Trypanosoma lucknowi is distinctive because of the large number of epimastigotes and trypomastigotes which, in culture, exhibit no movement or only a slight bending of the flagellar end. This limited motility coincides with a free flagellum which is either completely absent or rudimentary. The microorganism is cloned readily, and the description is based upon such cultures. Trypanosoma lucknowi shows pronounced differences from other trypanosomes of South Asian macaques and from “aflagellar” African trypanosomes. The ultrastructural demonstration of a cytostome and contractile vacuole suggests ultimate grouping with stercorarian trypanosomes. A 3-D reconstruction of the flagellar pocket/cytostome region is included.

Notes: The ultrastructure of the freshwater, heterotrophic dinoflagellate Peridiniopsis berolinense (Lemm.) Bourrelly resembles other dinoflagellates in the structure of its nucleus, theca, flagella, and mitochondria. Other features less frequently reported in related organisms include fine sub-sulcal fibers, collared pits in the flagellar base region, and unusual structures herein termed fibrillar lamellae. Numerous vesicles are present, some of whose contents are distinctly crystalline, while others contain what appears to be membranous material arranged in either whorls or parallel stacks; still other vesicles contain electron-dense, granular spheres. Of particular interest is the transitional helix present in the longitudinal flagellum, this being the first report of such a structure among the dinoflagellates. Plastids of any kind are lacking, and a peduncle is present and is used during phagotrophy.

Notes: Several axenic strains of pathogenic and nonpathogenic Entamoeba histolytica were tested for their capacity to digest native radioactive type I collagen gels and to produce liver abscesses when injected into the liver of newborn hamsters. The results demonstrate that the pathogenic strains of amebas (HM1:IMSS, HM3:IMSS, HM38:IMSS, and HK9) have a collagenolytic activity that closely correlates with their in vivo capacity to produce liver lesions. The nonpathogenic isolate (Laredo) did not show collagenolytic activity and failed to produce lesions in the liver of newborn hamsters. The results also demonstrate that type I collagen obtained from rodents and cats is degraded less by amebic collagenase than is bovine collagen, which is similar to human collagen. These findings suggest that species susceptibility to invasive infection may depend, among other factors, on the characteristics of the extracellular components of host tissues.

Notes: At Makthlawaiya, in the Paraguayan Chaco, the prevalence of Trypanosoma (Schizotrypanum) cruzi infection among both domestic Triatoma infestans and domestic dogs was 38%, and IgG anti-T. cruzi antibody was detected by the quantitative enzyme-linked immunosorbent assay (ELISA) in 80% (105/133) of human sera. Ninety percent (25/28) of T. cruzi strains isolated from both T. infestans and dogs showed heterozygous isoenzyme profiles for glucose phosphate isomerase, phosphoglucomutase and 6-phosphogluconate dehydrogenase. These strains appeared to be closely related to Bolivian zymodeme 2. Three Paraguayan T. cruzi strains showed homozygous isoenzyme profiles, similar to those of major Brazilian zymodemes. It was concluded that T. cruzi strains with heterozygous isoenzyme profiles predominate in domestic transmission cycles in this highly endemic area of the Paraguayan Chaco.

Notes: Results obtained in immunofluorescence localization studies involving three antisera, six species of ciliates, and a variety of fixation procedures suggest that superior results can often be obtained by fixing cells in 35–70% ethanol. Formaldehyde fixation appeared to induce redistributions of epiplasmic proteins and surface antigens which were not observed in ethanol-fixed cells. In addition, background fluorescence was significantly lower in ethanol-fixed cells than it was in cells fixed in aldehydes.

Notes: Actin has been identified in the ciliated protozoon Tetrahymena paravorax on the basis of the ultrastructural detection of filaments typically decorated with heavy meromyosin (HMM) in glycerinated microstome cells. These filaments are widely distributed in endoplasmic and cortical regions and can form bundles. They are particularly numerous in elongating cells; HMM-binding filaments run approximately parallel to rib microtubules in the ectoplasm of the right wall of the buccal cavity and seem to extend to the cytopharyngeal region, suggesting some role of actin in maintenance of the crest-trough pattern of ribbed wall and/or in formation of food vacuoles. Extensive actin bundles are observed below some membranellar areas and are thought to follow the course of the microtubular “deep fiber bundle.” The “fine filamentous reticulum” underlying the oral ribs and the “apical ring” extending beneath kinetosomes of ciliary couplets display filaments that do not bind HMM and are ˜ 14 nm in diameter. No evidence for actin in these structures was obtained in the present study. The “specialized cytoplasm” of the cytostome-cytopharyngeal region appears as an undecorated reticulum with 20 nm-spaced nodes. Occasionally HMM-binding filaments were found inside the macronucleus, just beneath its envelope. Actin is suggested to be involved in cell shaping and in control of the transport of food vacuoles.

Notes: Two allelic Mendelian mutations which confer a short flagella phenotype were used to explore flagellar size control in Chlamydomonas reinhardtii. When mutant/wild type quadriflagellate dikaryon cells were constructed, their two short flagella rapidly grew out to near wild type length. The kinetics of elongation suggest that the flagellar assembly process is not intrinsically self-limiting as a number of otherwise attractive models for size control require. Instead, we suggest that there exists a cellular machinery dedicated to flagellar size control and that the short-flagella mutations alter the machinery in some as yet unknown way. One of the mutants shows temperature-sensitive flagellar assembly, and both are flagellaless in acetate media. Genetic analysis indicates that the temperaturesensitive, acetate-sensitive, and short-flagella phenotypes have a common genetic basis. The responsible gene has been named shf-1, and it has been mapped to chromosome VI, approximately 5 map units from the centromere.

Notes: Fourteen strains of Naegleria australiensis, including the type strain, were compared for virulence for mice, maximum growth temperature, lectin agglutination, isoenzyme pattern, and total protein banding pattern. Their relation to other species of Naegleria also was compared by immunoelectrophoretic analysis. Strains with high virulence, comparable to that of N. fowleri, were found to be different in concanavalin A agglutination as well as with regard to zymograms and total protein patterns. Although serologically different from N. fowleri and reacting with N. australiensis antiserum in the fluorescent antibody test, these high-virulence strains differed in number of immunoelectrophoretic precipitin bands. Because of these results, the high-virulence strains are considered to be a subspecies of N. australiensis. The low-virulence strains showed minor differences from the type strain. Thus, N. australiensis does not appear to be as homogenous a species as N. fowleri. Pathogenic N. australiensis also seems to be more widespread than previously thought.

Notes: In Pleurotricha lanceolata, the ventral somatic infraciliature presents 13 frontoventral cirri, 5 transverse cirri, one row with 18–19 left marginal cirri and two rows of right marginal cirri of different length. On the dorsal side there are six longitudinal rows of dorsal bristles, four of them bipolar and the other two less than half body length. The oral infraciliature includes the adoral zone of membranelles, with 45–55 membranelles of three or four rows of kinetosomes each, and two undulating membranes (paroral and endoral membranes), each with two rows of kinetosomes. Some structures of the oral and somatic fibrillar systems have also been examined and are similar to those described in other species of hypotrichous ciliates.

Notes: Fecal samples of 36 ground squirrels, Spermophilus beldingi, from Tioga Pass (elev. ca. 3315 m) in the Sierra Nevada, California, yielded oocysts of Eimeria beckeri in nine squirrels, E. citelli in four squirrels, E. beldingii n. sp. in two squirrels, and degenerated, unidentifiable oocysts in ten squirrels. Eimeria beldingii n. sp. oocysts are ellipsoidal, 30–34 × 24–30 (mean 32 × 26) μm with a two-layered, rough, striated wall, without a micropyle or residuum, with polar granules; they contain ellipsoidal or ovoid sporocysts 11–15 × 9–12 (mean 13 × 10) μm with a Stieda body and residuum.

Notes: Ten years of research on digestive vacuoles (phagosomes) of Paramecium caudatum have revealed sequential changes both within the vacuole lumen as well as within the surrounding membrane. Four vacuole stages can be recognized by a combination of thin section and freeze-fracture ultrastructural features. Three sets of vesicles (discoidal vesicles, acidosomes, and lysosomes) fuse with the vacuole, each at a predetermined stage, to bring about these membrane and physiological changes. At various times membrane is removed as vesicles from the vacuole surface, which has the effect of regulating vacuole size. Membrane recycling, membrane replacement, and specific membrane to membrane recognition all appear to be operating during the digestive cycle. Details of these events are summarized in this address and a number of unanswered questions suggest areas for future research.

Notes: Reports of Cryptosporidium in various hosts and cross-transmission experiments are reviewed. Cryptosporidium has been found in mammals (Primates, Artiodactyla, Perissodactyla, Carnivora, Lagomorpha, and Rodentia), birds, reptiles, and fish. The only cross-transmission attempts that have been made have been from mammals to other mammals and to a few birds. Names have been given to 19 “species,” but it is concluded that only four of these should be considered valid at present. These are: C. muris Tyzzer, 1907 in mammals, C. meleagridis Slavin, 1955 in birds, C. crotali Triffit, 1925 in reptiles, and C. nasorum Hoover, Hoerr, Carlton, Hinsman & Ferguson, 1981 in fish.

Notes: In vitro excystation of sporozoites of the heteroxenous coccidian Caryospora simplex Léger, 1904 (Apicomplexa: Eimeriorina) is described. Sporocysts freed mechanically from oocysts released a maximum of 51% of their sporozoites within 45 min at 25°C and a maximum of 74% within 20 min at 37°C when incubated in a 0.25% (w/v) trypsin–0.75% (w/v) sodium taurocholate (bile salt) excystation solution. At emergence from sporocysts, sporozoites were weakly motile then became highly active after about 2 min in excystation solution. Sporozoites within sporocysts exposed to bile salt only became highly motile within 25 min at 25°C and within 15 min at 37°C but did not excyst. When exposed only to trypsin at the above temperatures, the Stieda body dissolved; the substieda body remained intact, and the sporozoites exhibited only limited motility within sporocysts; only a few excysted. Intact, sporulated oocysts incubated at 25° or 37°C in 0.02 M cysteine-HC1 and a 50% CO2 atmosphere for 18 h had no morphologic changes in the oocyst wall. Further incubation of these intact oocysts in excystation solution for 30 min at 37°C caused neither motility of sporozoites within sporocysts nor excystation. Grinding oocysts for 30 sec in a motor-driven, teflon-coated tissue grinder caused motility of some sporozoites within sporocysts but did not result in excystation.

Notes: The effect of the cationic permeant fluorescent dye, rhodamine 123 (R123), on the in vivo growth of Plasmodium yoelii was examined. Plasmodium yoelii-infected mouse erythrocytes were incubated in vitro with R123 and injected intravenously into mice. Examination of daily parasitemias showed that R123 delayed parasite growth whereas rhodamine 110, a neutral compound, and fluorescein, a negatively charged fluorescent dye, did not. Infected erythrocytes treated with R123 were not cleared from the circulation even 7 h after injection. Quantitation of cell-associated R123 by spectrophotometry revealed that infected cells with increased levels of R123 considerably prolonged the 2% prepatent period, the time required for the parasite to develop a 2% parasitemia. Degenerating parasites within and outside the host erythrocytes were observed on day 1 of infection in the mice. Thus it follows that R123, which accumulated in infected erythrocytes, inhibits the growth of P. yoelii; moreover, when R123-labeled infected erythrocytes were treated with 1–10 μM carbonylcyanide m-chlorophenylhydrazone (CCCP), a proton ionophore, to release R123 from the cells, the inhibitory effect on the growth rate of P. yoelii was partially reversed.

Notes: Oocysts of Caryospora corallae n. sp. were isolated from the feces of three Emerald Tree Boas Corallus caninus. The spherical oocysts of C. corallae averaged 22.4 μn (range 18.7 to 24.6) in diameter and were lacking a micropyle and oocyst residuum; a polar granule was present. The ovoid sporocysts measured 19.1(17.6-20.0) × 13.1(11.7-14.0) μm and a sporocyst residuum and a Stieda body were present. The oocyst wall was approximately 1 μm thick. The sporulation was completed in about 5–6 days at 23 ± 2°C. This is the first report of the genus Caryospora from Corallus caninus a member of the Boidae.

Notes: The release, dispersal, and ultrastructure of juveniles arising through multiple fission in the benthic foraminiferan Allogromia sp., strain NF (Lee & Pierce, 1963) has been examined by light and electron microscopy. An extensive reticulopodial network participates in the dispersal of fully differentiated young as they emerge from the fragmented parental test. During the earliest stages of release, offspring are of two classes—aroused and unaroused. Unaroused juveniles, which have not extended pseudopods, attach externally to the network and are transported bidirectionally along its surface. Aroused juveniles, which have extended pseudopods and are in protoplasmic continuity with the network, move quickly to the periphery of the network. Within 24 h, juveniles establish a communal “feeding reticulum” in which dispersed individuals are in protoplasmic continuity with neighbors via a common reticulopodial network. At the ultrastructural level, the cell body cytoplasm of unaroused juveniles contains numerous patches of a paracrystalline material, which disappears as their pseudopodia are extended to join the communal feeding reticulum. This paracrystalline material therefore appears to be a temporary reservoir of precursors required for pseudopod construction.

Notes: . The paper is concerned with the principles upon which coccidia of the genus Eimeria may be characterized. Reference strains for comparative purposes usually are not available and the limitations of morphological data for speciation are discussed. The value of other parameters are considered such as host and site specificity, pathogenicity, immunological specificity, pre-patent period, sporulation time, enzyme variation, and DNA buoyant density. The weight afforded to each of these parameters for specific identification may vary according to the parasite and host studied. Determinations of physiological and behavioral characteristics that are now becoming available should be included in species definitions wherever possible.

Notes: . Eleven female goats (Nos. 1 to 11) were each inoculated orally with 104 sporocysts of Sarcocystis capracanis, and four female goats (Nos. 12 to 15) were not inoculated. Between 31 and 69 days after inoculation (DAI) goats were mated with a single buck; one goat (No. 5) did not breed. Eight inoculated goats were challenged with 105or 106 sporocysts, 135 DAI. Two of four goats challenged with 106 sporocysts and one of three goats challenged with 105 sporocysts aborted one month before the expected time of parturition. The three inoculated goats that were not challenged delivered healthy kids. All inoculated goats including the nonpregnant one (No. 5) were only mildly ill from the primary or challenge inoculations. Two of the four control goats challenged with 5 × 104 or 105 sporocysts aborted 21 days later, and both died of sarcocystosis 25 and 88 DAI. The two remaining control goats delivered normal kids. The results indicate that immunization prior to pregnancy protects some but not all goats from .Sarc0c.es/is-induced abortion.

Notes: . Whereas excystation of sporozoites from oocysts of most coccidian species requires exposure to reducing conditions followed by pancreatic enzymes and bile salts, sporozoites of a bovine isolate of Cryptosporidium excysted without exposure to either reducing conditions or to pancreatic enzymes and bile salts. Without prior exposure to reducing conditions, a high percent excysted after incubation in a mixture of trypsin and bile salts in Ringer's solution; fewer excysted after incubation in tap water, even fewer after incubation in salt solutions, and none after incubation in saliva. Excystation, generally greater at pH 7.6 than at pH 6.0 and at 37°C than at 20°C, was observed as early as 1 h after incubation in water or the trypsin-bile mixture. These findings provide circumstantial evidence that oocysts of Cryptosporidium can excyst in extraintestinal sites and liberate sporozoites that can initiate autoinfection.

Notes: . Changes in nuclei and nucleoli of cells of chicken cecum infected with Eimeria tenella were studied in living cells by interference microscopy and in fixed and stained tissues using light level microscopy. As soon as merozoites began to transform into second generation meronts, there was an increase in the size of both the nucleus and the nucleolus of the host cell. The dry weight of the nucleus increased somewhat, but there was a greater increase and a correlation of the dry mass of the nucleolus with the size of the parasite as measured by interference microscopy. In fixed and stained tissues, there was a correlation between the area of the nucleolus and the area of the parasite. Removal of nucleic acids with DNase and/or RNase showed high concentrations of both in the nucleoli and a residue of protein. The increased nucleolar size indicates a high level of transcription in infected cells and allows the conclusion that the parasite somehow induces transcription to occur. Since transcription is a highly specific process, the high degree of host and site specificity shown by nearly all coccidia is consistent with a hypothesis that the coccidia share a portion of the host genome.

Notes: . Twenty of 35 roe deer (Capreolus capreolus), eight of 12 red deer (Cervus elaphus), and nine of 21 fallow deer (Cervus da ma) but none of four moose (Alces alces) examined from April to November 1983 were infected with trypanosomes. Morphometric data of the bloodstream trypomastigotes from the three deer species differed significantly. This appears to be the first report of stercorarian trypanosomes from Cervidae in the Old World and the first description of representatives of the subgenus Megatrypanum in the three deer species.

Notes: Book Review in this ArticlesDubitskii, A. M, ed. 1983. Natural Population Regulatory Factors Aflecting Biting Flies in S.E. Kazakhstan, USSR.Walliker, D. 1983. The Contribution of Genetics to the Study of Parasitic Protozoa.Martin, G. W., Alexopoulos, C. J. & Farr, M. L. 1983. The Genera of Myxomycetes.Goodwin, B. C, Holder, N. & Wylie, C. C, eds. 1983. Development and Evolution.

Notes: In vitro culture of Plasmodium falciparum-infected human erythrocytes (RBC) has permitted systematic study of human host-parasite relations. In this study the effect of aspirin in the culture system was examined by using serum from blood of fasting, healthy male volunteers, before and after the ingestion of aspirin. The addition of aspirin-containing serum disturbed parasite growth and development: 0-1/2 dilutions of treated/control sera inhibited parasite development, with nuclear pyknosis, pyknotic extracellular parasites (trophozoites) in the media, decreased numbers and sizes of “rings” (early trophozoites), and an increased number of later trophozoites and schizonts. Paradoxically, while the incorporation of [3H]isoleucine into protein was not affected by the aspirin-containing sera, the incorporation [3H]hypoxanthine was significantly changed and did not correlate with morphological evidence of cytotoxicity. Thus, the so-called “incorporation” of a radioactive tracer is not a fully reliable index of parasite growth in the presence of certain compounds. The findings underscore the importance, in this culture system which employs human serum, of avoiding serum from donors who have recently ingested aspirin.

Notes: Leighton tubes containing monolayers of human embryonic lung cells were inoculated with 70,000 or 30,000 sporozoites of the viperid coccidium Caryospora simplex and examined at 1, 2, 4, 6, 8, 10, 12, 14, 16, and 18 days post-inoculation (PI). By day 1 PI, sporozoites had penetrated cells and were within parasitophorous vacuoles. Most sporozoites became spherical and then underwent karyokinesis several times between days 2 and 6 PI. Mature Type I meronts were found on days 6–16 PI and contained 8 to 22 short, stout merozoites. Mature Type II meronts were present on days 10–18 PI and contained 8 to 22 long, slender merozoites. Developing gamonts (undifferentiated sexual stages) were observed on days 14 and 16 PI. Mature micro- and macrogametes and thin-walled unsporulated oocysts were present on days 16 and 18 PI. Attempts to sporulate oocysts in tissue culture medium or in a 2.5% (w/v) aqueous solution of K2Cr2O7 at 25/°C and 37°C were unsuccessful; only a few oocysts developed to the contracted sporont stage. Four Swiss-Webster mice injected intraperitoneally with merozoites obtained from Leighton tubes on day 10 PI did not acquire infections. This is the second coccidium reported to complete its entire development, from sporozoite to oocyst, in cell culture.

Notes: Evidence for meiosis was demonstrated electron microscopically for the first time in Pneumocystis carinii in rat alveoli by the observation of synaptonemal complexes followed by nuclear divisions. Synaptonemal complexes indicating meiotic nuclear divisions were observed in uninuclear precysts. Additionally, owing to the use of tannic acid as a fixative, spindle microtubules were also observed for the first time in the precyst. Based on these facts, a new life cycle of the organism is proposed. The precyst has generally been considered an intermediate form between the trophozoite and the cyst. The present paper proposes that the precyst is additionally defined as the cell in which eight intracystic bodies are produced through meiotic reduction. The most characteristic feature of the precyst is a clump of mitochondria in the cytoplasm. We divide the precyst phase into three forms, which are named early, intermediate, and late. Synaptonemal complexes were only observed in the early precyst, which is a uninuclear cell with a thin pellicle. In the intermediate precyst, nuclear divisions are observed as follows: meiosis I produces two haploid nuclei and each of these divides at meiosis II producing four nuclei. After that, another postmeiotic mitosis takes place, resulting in eight haploid nuclei. In the late precyst, a delimiting membrane originates from the mother plasmalemma and surrounds the daughter nuclei and a small portion of the adjacent cytoplasm. Finally, when the eight intracystic bodies are complete, the precyst changes to a cyst. Thus, we deduce that intracystic bodies resulting from meiotic nuclear division are haploid and, after excystation, they are haploid trophozoites. We consider that this process can be called sporogony. Although we could not distinguish between the haploid and the diploid trophozoite, it is quite plausible that copulation occurs, probably in host alveoli.

Notes: Lepidotrachelophyllum fornicis n. g., n. sp. was discovered in White Lake, Ontario, Canada, under winter ice. The genus is Trachelophyllum-like, being highly flattened, elongate, and very extensible. The major feature that separates it from other genera in the family Trachelophyllidae is the presence of a dense layer of organic scales which covers the exterior of the cell and through which the cilia emerge. The scales are composed of filamentous material which is organized as an ovoid structure. The “rim” of the baseplate is formed of interwoven filaments. The baseplate is broken by circular or polygonal apertures. The same filaments form an arched superstructure broken by even larger, less regular apertures.

Notes: Plasmodium falciparum was grown in human erythrocytes in vitro and the effect of chloramphenicol, erythromycin, and tetracycline on growth and maturation of the parasites and on their ability to incorporate [3H]isoleucine into protein was observed. Exposure of rings to high concentrations of chloramphenicol had little effect on subsequent maturation of the rings whereas brief (4 h) exposure of trophozoites caused a dose-dependent inhibition of subsequent ring formation. Incorporation of [3H]isoleucine into protein was not affected during at least 6 h of exposure to high concentration of the three drugs examined, but appreciable inhibition was observed after 21 h, with chloramphenicol being the least effective inhibitor. These results suggest that there is a stage-specific effect of inhibition of mitochondrial protein synthesis on subsequent development and that the mitochondria are essential for growth and development even though they lack a functional Krebs cycle.

Notes: The localization of proteins and polysaccharides in the cyst wall of a ciliate, Histriculus muscorum, was examined by light and electron microscope cytochemistry and by using an enzyme digestion test on thin sections. The endocyst and ectocyst were digested by treatment with pepsin or protease VI. The endocyst was intensely PAS-positive and alcian blue-positive. The ectocyst was also PAS- and alcian blue-positive, but the reaction was weaker than that of the endocyst. At the electron microscope level, an intensely positive reaction to methenamine silver was observed in the endocyst and a weak reaction in the ectocyst of the mature cyst. In the ectocyst of the encysting organism, however, the reaction to methenamine silver was more intense than that of the mature cyst. These results demonstrate the possible presence of glycoproteins in the ectocyst and endocyst. The mesocyst was negative to all cytochemical and enzyme digestion tests examined. The cyst wall, isolated by sonication, was analyzed by SDS-polyacrylamide gel electrophoresis. Two bands, 190 and 140 kilodaltons, were specific for the cyst wall. The 190 kilodalton band was the only PAS-positive band and its localization in the cyst was was discussed.

Notes: Electron microscopic examinations of Glugea hertwigi and Spraguea lophii spores indicated the presence of a single plasma membrane; however, this membrane remained in the spore during the discharge of the sporoplasm from the spore. Although discharged spores retained the old plasma membrane, the extruded sporoplasms acquired a new plasma membrane. In order to determine where the new plasma membrane came from, we used two fluorescent probes with membrane affinities. The markers were tested on unfired and discharged spores. The probe, N-phenyl-1-naphthylamine (NPN), labeled the polaroplast membrane in addition to the apolar groups in the posterior vacuoles of unfired spores. After spore discharge, NPN label disappeared from the spore ghosts except for a slight fluorescence on residual plasma membranes. Much of the NPN-labeled membrane reappeared after spore discharge on the outer envelope of discharged sporoplasms. The probe chlorotetracycline (CTC) labeled calcium-associated membranes of spore polaroplasts. During spore discharge, the CTC fluorescence shifted from the polaroplast organelle of unfired spores to the outer envelope of discharged sporoplasms. These results indicate that the polaroplast organelle may provide the new plasma membrane for discharged microsporidian sporoplasms.

Notes: Enzyme cytochemistry was used to determine when acid phosphatase (AcPase) becomes associated with the digestive vacuoles (DVs) of axenically grown Paramecium caudatum that were pulsed with latex beads for 2–3 min. When cells were incubated in the Gomori medium, AcPase was not observed in the discoidal vesicles, the acidosomes, and the newly released DVs up to 3 min old or in most DVs 3–6 min old. The number of AcPase-positive DVs increased to 56% when DVs were 12–18 min old. Similar results were obtained using the napthol AS-TR phosphate-hexaotized rosanilin method at the light microscopic level where hundreds of DVs were scored though the maximal level of positive DVs obtained by this method was lower. In addition to DVs of specific ages, AcPase was found in ER, in some Golgi vesicles, and small vesicles similar in diameter to Golgi vesicles which may represent primary lysosomes in this ciliate. Larger vesicles abundant near the DV-II were only partially filled with reaction product. These vesicles, which could be identified by their paracrystalline sheets and a prominent glycocalyx lining the luminal surface of their membranes, fit the definition for secondary lysosomes. These results, which indicate that lysosomes fuse with DVs only after they have attained a certain age, suggest the existence of specific recognition factors on the membranes of secondary lysosomes as well as DV-II.

Notes: The trypanosome genome contains several hundred (and perhaps several thousand) genes for the trypanosome variable surface glycoproteins (VSGs). In an individual trypanosome only one of these genes is expressed at a given instant; the others are transcriptionally silent. This differential gene expression is responsible for the sequential antigenic variation displayed by trypanosomes. It is mediated by two types of genomic rearrangements of these VSG genes. The best understood rearrangement type is the formation of a transcriptionally-active expression-linked extra copy (ELC) of a transcriptionally-silent basic copy (BC) gene. This duplication and translocation event places the ELC near a chromosomal end (a telomere) where it is apparently located downstream from a strong promotor. Some VSG genes are not expressed via this ELC mechanism. These genes, which seem to already be near telomeres, are activated by a different non-duplication associated (NDA) type of mechanism. We have used recombinant DNA techniques to clone and determine the sequences of genes expressed by both the ELC and NDA mechanisms. Comparison of these sequences reveals that sequences flanking the VSG coding regions are similar. This indicates that there is a sequence correlation between the two mechanisms of expression. We have also shown that when bloodstream trypanosomes expressing a specific VSG via the ELC mechanism are established in culture the resultant procyclic trypanosomes rapidly stop synthesizing the VSG mRNA (and the VSG) but retain the ELC of the VSG gene. This demonstrates that transcription of an ELC can cease without the loss of that ELC and may indicate the presence of other factors regulating VSG gene transcription.

Notes: Morphologic and biometric data on bloodstream stages of Trypanosoma melophagium are presented. An increasing parasitemia with 111 trypomastigote stages of T. melophagium were found in Giemsa-stained thin blood smears taken from a splenectomized, cortisone-treated sheep recently infested with Melophagus ovinus infected with T. melophagium. The arithmetic mean and standard deviation in μm of the distances between posterior end and kinetoplast were 14.7 and 2.9, from the kinetoplast to the center of the nucleus 5.1 and 1.1, and from there to the anterior end 19.5 and 1.9. The free flagellum measured 6.0 μm ± 1.6 μm. The median and the range of the central 70% of values (median ± 35%) of the nuclear index were 1.1 and 0.9–1.2 and of the kinetoplastic index 3.8 and 3.3–4.9. The same data in μm for the maximal width were 3.1 and 2.1–4.6, and for the width at the level of the nucleus 2.9 and 2.2–4.6. The larger and smaller diameters of the nucleus measured 2.6 (2.2–3.7) μm and 1.7 (1.3–1.7) μm, respectively. The corresponding kinetoplast diameters were 1.1 (0.9–1.3) μm and 0.9 (0.6–0.9) μm, respectively.

Notes: Two strains of Trichomonas vaginalis, JH162A, with low pathogenicity, and Balt 44, with high pathogenicity, as well as one highly pathogenic strain, KV-1, of Tritrichomonas foetus were studied by freeze-fracture electron microscopy.The protoplasmic faces (PFs) of the cell membranes of all three strains of both species had similar numbers of intramembranous particles (IMPs); however, the particles in the external faces (EFs) of these membranes were least abundant in Trichomonas vaginalis strain Balt 44 and most numerous in those of strain JH162A of this species. In Tritrichomonas foetus strain KV-1 the number of IMPs in the EF was close to but somewhat lower than that in the mild strain of the human urogenital trichomonad. In both species, the anterior, but not the recurrent, flagella had rosette-like formations, consisting of ∼9 to 12 IMPs on both the PFs and EFs. The numbers and distribution of the rosettes appeared to vary among different flagella and in different areas of individual flagella of a single organism belonging to either species. The freeze-fracture electron micrographs provided a more complete understanding of the fine structure of undulating membranes of Trichomonadinae, as represented by Trichomonas vaginalis, and of Tritrichomonadinae (the Tritrichomonas augusta-type), as exemplified by Tritrichomonas foetus, than was gained from previous transmission and scanning electron microscope studies. Typically three longitudinal rows of IMPs on the PF of the recurrent flagellum of Trichomonas vaginalis were noted in the area of attachment of this flagellum to the undulating membrane. The functional aspects of the various structures and differences between certain organelles revealed in the two trichomonad species by the freeze-fracture method are discussed.

Notes: The kinetics of differentiation and maturation of phagocytic cells during the acute and chronic stages of experimental Chagas' disease was examined by monitoring changes in expression of peroxidase (PO), nonspecific esterase (NSE), C3b receptors (CR), Fc receptors (FcR), and phagocytic ability of cells in the blood, spleen, and peritoneal cavity. The significant changes recorded in the blood were: marked increases in the percentages of CR- and FcR-positive adherent cells during both the acute and chronic phase; Ia-positive cells increased two-fold in the acute period and remained elevated in the chronic stage. In the spleen, the major alterations recorded during both the acute and chronic stages were: two- to three-fold increases in the percentages of NSE- and PO-positive adherent cells and three- to four-fold increases in the proportions of CR- and FcR-positive cells. In addition, Ia-positive cells increased from 70% to approximately 90% of the adherent cell population. In the peritoneal cavity, a two- to four-fold elevation in the percentages of both PO- and NSE-positive cells was observed. The number of Ia-positive cells increased from 10% before infection to 85–90% during the acute phase and to 96–98% during the chronic period. All of the changes described above occurred in the absence of noticeable increases in phagocytic ability except for an elevation in the percentage of circulating latex-ingesting cells seen during chronicity. These results indicate that infection with Trypanosoma cruzi alters the pathways of differentiation of cells of the mononuclear phagocyte lineage.

Notes: Development of the swine coccidium, Isospora suis, in embryonated chicken eggs is described. The allantoic cavities of eight-to-ten-day-old white Leghorn embryos were inoculated with either 100,000 or 200,000 sporozoites. Developmental stages morphologically similar to those found in the intestines of piglets were present in the endodermal layer of the chorioallantoic membrane (CAM), beginning three days post inoculation (PI). No stages were found in the mesodermal or ectodermal layers of the CAM and none were observed in heart, lung, liver, or spleen. Type I meronts and merozoites were found on days 3 through 10 PI. Type II meronts and merozoites were found days 4 through 10 PI. Mature microgamonts, macrogamonts, and oocysts were found on days 7 through 10 PI. Oocysts appeared to be retained in the endodermal cells and in ovo sporulation did not occur. Attempts to sporulate CAM-derived oocysts were not successful. Isospora suis was not pathogenic for embryos under the conditions of this study. This study represents the first fully documented report of complete development of a mammalian coccidium in chicken embryos.

Notes: Plasmodium falciparum-infected human erythrocytes grown in vitro do not release 14CO2, when incubated in the presence of [1-14C]glutamate, despite the presence of glutamate dehydrogenase, implying the absence of α-ketoglutarate dehydrogenase activity and the lack of functional tricarboxylic acid cycle in the human malaria parasite. Cultures incubated with [14C]bicarbonate, however, fix CO2 into acid-stable metabolites; CO2 fixation proceeds linearly for up to two hours after an initial brief lag and may contribute appreciably to the metabolism of the parasite.

Notes: A geneological study shows that about 4% of the cells in healthy, adequately fed Amoeba proteus cultures are inviable. Two different categories of inviability are distinguished. About 44% of all inviability involves twin sisters formed at a division. Another 39% involves single cells with viable sisters and nieces. The inviable singles usually die more rapidly and show fewer visible abnormalities than the twins. The mothers of inviable twins show an increased interdivision time compared to mothers of inviable singles. Both categories of death are more rapid than starvation. The 17% of the deaths which involve aunt-niece pairs appear to be special cases of twin sister or single cell deaths. There is no evidence for stem line division where a cell forms only one viable daughter for several generations. It is proposed that death is a normal occurrence in amoeba populations. It occurs regardless of culture conditions and may be a measure of accumulated lethal mutations in an asexual polyploid organism.

Notes: Ciba Foundation Symposium 94: 1983. Malaria and the Red Cell. Pitman, London, Medical Education Division, CIBA Pharmaceutical Company, West Caldwell, NJ 07006. 257 pp. £25.00/$35.00. Jira, J. & V. Kozojed. Toxoplasmose-Toxoplasmosis 1968–1975, Vols. 1 & 2. Gustav Fischer Verlag-Stuttgart. 207 & 395 pp. About DM 180. Phillips, R. S. 1983. Malaria. Edward Arnold, 300 North Charles St., Baltimore, MD 21201. 257 pp.

Notes: Groups of mice received double infections with the Y and F strains of Trypanosoma cruzi, the first inoculum of either strain being followed by a second inoculum of the other strain on day 5, 15, 30–40, or 60–65. Parasites were re-isolated from blood into culture, either directly or with an intermediate passage in gamma-irradiated mice, at intervals between 7 and 35 days after the second inoculation. Strain identification in the re-isolated material was by electrophoresis of kDNA fragments generated by the EcoRI restriction endonuclease and by electrophoresis for glucosephosphate isomerase isozymes. Both strains were identified in 22% of reislotes originating from the experimental mice and only one of them was present in the remaining re-isolates, strain F being the most frequent. In some instances either Y or F was re-isolated from the same blood source, depending on whether culturing had been preceded or not by passage through a mouse. These results are certainly related to strain differences in the various aspects of host-parasite relationship and, possibly, growth rates in culture. The results demonstrate that: (1) more than one strain of T. cruzi can coexist in the same host; (2) the timing and method of parasite isolation from the vertebrate host act as selective factors, and further passages (inmice or cultures) may completely eliminate one (or more) strain from originally mixed trypanosome populations, and (3) kDNA restriction “fingerprints” and isozyme profiles are simple, sensitive, and reliable techniques for strain identification both in single and mixed preparations.

Notes: Hepatozoon mocassini (Laveran, 1902) n. comb. from Agkistrodon piscivorus leucostoma (water moccasin) is redescribed by light microscopic study of all developmental stages and reclassified since mature oocysts contained sporocysts. Formerly this species was assigned to the genus Haemogregarina on the basis of a description of the gamonts. A neotype is designated because the original specimens cannot be located. Mature oocysts, containing sporocysts, developed in the hemocoel of the experimental host Aedes aegypti. These oocysts proved infective for A. piscivorus leucostoma when administered orally.

Notes: Unikaryon matteii n. sp. (Microsporida, Unikaryonidae) parasite le tube digestif, les tubes de Malpighi, les muscles et le tissu adipeux de Nisotra sp. (Coleoptera, Chrysomelidae). Elle se développe en contact direct avec le cytoplasme de la cellule hôte et ne présente jamais de diplocaryon.Les mérontes sont limités par une simple membrane plasmique. Leur cytoplasme présente quelques saccules de reticulum endoplasmique et des vésicules golgiennes. Les mérontes uninucléés sont globuleux (2 μm de diamèGtre). Les mérontes binucléés sont allongés (5 × 1.5 μm) et se divisent par simple étranglement médian pour donner deux nouveaux mérontes uninucléés, qui pourront évoluer en sporontes.La sporogonie est disporoblastique. Les sporontes et les sporoblastes sont limités par une paroi d'environ 15 nm d'épaisseur, et leur cytoplasme présente un reticulum endoplasmique développé. Les sporontes uninucléés (2 μm de diamétre) deviennent binucéés (5 × 2 μm), puis subissent une division binaire pour donner deux sporoblastes uninucléés. Les sporoblastes, d'abord de forme irrégulièGre deviennent ovoïdes (2.5 × 2 μm) puis évoluent en spores.Les spores sont ovales et uninucléées (3.72 ± 0.39 μm × 1.96 ± 0.15 μm). Elles possèGdent un filament polaire qui décrit 5 à 12 tours de spires. Leur polaroplaste est uniquement lamellaire, mais subdivisé en deux parties: I'une, antérieure, constituée de saccules aplatis, I'autre, postérieure, constituée de saccules dilatés.La description d'une deuxièGme espèGce d'Unikaryon chez les coléoptères confirme le développement de ces parasites chez les insectes, et pose le problèGme de la validité de certaines Nosema d'insectes dont les spores sont uninucléées.〈section xml:id="abs1-2"〉〈title type="main"〉ABSTRACT Unikaryon matteii n. sp. (Microsporida, Unikaryonidae) is a parasite of gut, Malpighian tubules, muscles, and fat body of Nisotra sp. (Coleoptera, Chrysomelidae). It develops diffusely in the host cell cytoplasm and is unikaryotic throughout merogony and sporogony.The meronts are surrounded by a simple plasma membrane. Their cytoplasm contains little endoplasmic reticulum and some Golgi vesicles. Uninucleate meronts are globular (2 μm in diameter). Binucleate meronts are elongate (5 × 1.5 μm); by binary fission they give rise to two uninucleate meronts, which may develop into sporonts.Sporogony is disporoblastic. Sporonts and sporoblasts are bounded by an electron-dense wall about 15 nm thick, and their cytoplasm contains some flattened cisternae of endoplasmic reticulum. The uninucleate sporonts (2 μm in diameter) become binucleate (5 × 1.5 μm) and undergo binary fission to produce two uninucleate sporoblasts. The sporoblasts, at first irregular in outline, become ovoid (2.5 × 2 μm) and give rise to spores.The spores are uninucleate and oval (3.72 ± 0.39 μm × 1.96 ± 0.15 μm). They have a polar filament with 5 to 12 coils and a Iamellate polaroplast divided into two parts: an anterior part composed of flattened sacs and a posterior part made up of swollen sacs.The description of a second species of Unikaryon in a coleopteran confirms the development of these parasites in insects. The validity of some Nosema of insects which have uninucleate spores is discussed.

Notes: The combination of KCl + acriflavine + Ca2+-poor condition, known as conjugation-inducing-chemicals, was found to be autogamy-inducing-chemicals as well. Suspension of a single cell of Paramecium multimicronucleatum, syngen 2 in this medium for three hours or more resulted in autogamy that was evidenced by cytological similarity to conjugation.

Notes: Giardia sp. cysts were found at levels of 4,000–450,000/378,500 liters (100,000 gallons) in sewage effluents from three of seven sewage treatment plants in Sangamon County, Illinois, in June, July, and August 1981. Effluent from the positive plants is discharged into Lake Springfield (the present source of the city of Springfield's water supply) or the Sangamon River.

Notes: Light microscopy studies of Culicosporella lunata (Hazard & Savage), a parasite of the mosquito Culex pilosus (Dyar & Knab), revealed two sporogonial sequences. One sequence begins with diplokaryotic meronts that undergo repeated nuclear divisions to produce sporogonial plasmodia with nuclei in diplokaryotic arrangement. These plasmodia form rosette-like clusters of sporoblasts during incomplete cytokinesis and, eventually, binucleate spores. These spores initiate infections in healthy larvae when they ingest spores. The second sequence begins with diplokaryotic meronts that undergo karyogamy and meiosis to form Thelohania-like sporonts and haploid spores. Anomalies are often observed in these sporonts which result in aberrant spores, usually fewer than eight, in an accessory (pansporoblastic) membrane. Normal haploid spores are morphologically similar to those of species of Amblyospora. The genus and the type species are redefined based on new information presented here and it and the type species are placed in the family Amblyosporidae.

Notes: First and second generation meronts of Eimeria vermiformis developed in epithelial cells of the crypts of Lieberkühn. They were usually between the host cell nucleus and the basement membrane. Sporozoite organelles dedifferentiated with the first generation meront's development except for the refractile body and the apical complex, which persisted. After several nuclear divisions, the apical complex dedifferentiated further until only micronemes remained attached by a duct system to the plasmalemma. The form of the apical complex was highly variable. Sometimes the duct system was absent and the micronemes were attached directly to the plasmalemma or a dense material on it. Crescent body-like material was often present in the parasitophorous vacuole next to the microneme structure. The microneme structure was not present in second generation meronts but evaginations of the plasmalemma, cytoplasmic outpocketings, and cytoplasmic vesicles were associated with the round granular bodies in the parasitophorous vacuoles. During first generation merogenesis, invaginations from the parasitophorous vacuole formed channels into the meront along which merozoites budded. Micropores were often at the ends of these invaginations. These and other micropores of the meront had a dense U-shaped band for a collar while those of the merozoites had a collar with a double band of dense material that connected to the inner membrane. First generation merozoites budded randomly from the meront, resulting in a residual body that was usually in the middle of the parasitophorous vacuole. Second generation merozoites budded in one direction, resulting in a peripheral residual body and merozoites that were parallel in an oblong parasitophorous vacuole.

Notes: Ultrastructural observations on the sporocarp of the protostelid Cavostelium apophysatum are presented, including information about the mechanism of sporocarp development. The onset of sporogenesis is marked by cessation of trophic activity and the secretion of a protective sheath. The protoplast gradually molds itself into two distinct zones approximating the shape of the final sporocarp–a hyaloplasmic pre-stalk zone and a globose incipient spore zone. The protoplast in the stalk zone deposits a fibrillar and amorphous stalk acropetally as the stalk protoplast moves into the incipient spore region. The last portion of the stalk to be deposited is the apophysis, a hollow cup-like structure at the stalk apex. Spore wall deposition begins as the stalk nears completion. The wall consists of a single electron-dense layer ornamented with hollow cones and solid projections. The mechanism of sporocarp development in C. apophysatum is compared to the developmental patterns of the protostelids Planoprotostelium aurantium and Schizoplasmodiopsis amoeboidea.

Notes: Cytidine deaminase (cytidine aminohydrolase, 3.5.4.5) is present in Crithidia fasciculata (a mosquito parasite) and in Trypanosoma cruzi (a human pathogen). The enzyme from C. fasciculata deaminated both cytidine and deoxycytidine, the affinity for the former being much lower than the latter. Affinities for both substrates are equal for the T. cruzi enzyme. The production of the enzyme in C. fasciculata was significantly stimulated by the addition of a number of pyrimidine nucleosides (cytidine, uridine, 5-bromouridine, thymidine, orotidine) to the culture media. Only cytidine stimulated enzyme production in T. cruzi. The enzyme from both organisms was unstable in air, even in the frozen state. Stabilization was achieved under anaerobic conditions.

Notes: The holdfast apparatus fills the posterior half of the larva; it is comprised of cytoplasmic granules called heterosomes and of about twenty collecting canals which converge at a septate chamber, the rosette. The latter opens to the exterior by a secretory appendage called the podite. My hypothesis is that, when the larva attaches to a substrate, the heterosomal contents empty into the collecting canals and are mixed in the rosette. With the aid of the podite, this secretion is applied to the gill substrate where it forms the so-called style of the future adult. The holdfast apparatus of the adult Spirochona comprises two regions of different nature: the pseudostyle, which is the posterior part of the cell, and the style which is an extracellular secretion. The style looks like a truncated cone and adheres firmly to the substrate. The upper face of the style shows 16–18 stylonemes which are inserted in the crypts of the pseudostylar rosette. The latter corresponds to the larval rosette, and the crypts communicate with a chamber and numerous suprastylar acini, which represent the remnants of the larval collecting canals. Except for a few details, the holdfast apparatus appears to be similar among all the chonotrichs studied to date. This apparatus differs from that of the Suctoria and of the Peritricha. It has some analogies with the “mouth-rosette” complex of the Apostomatida. Finally, the presence of a podite in a chonotrich larva is new evidence supporting a closer systematic relationship between the Chonotrichida and the Dysteriidae.〈section xml:id="abs1-2"〉〈title type="main"〉RESUMEL'appareil de fixation occupe la moitié postérieure de la larve; il est composé de granules cytoplasmiques, les hétérosomes, et d'une vingtaine de canaux collecteurs convergeant vers une chambre septée appelée rosette. Celle-la communique avec l'extérieur par un appendice sécréteur, le podite. II est supposé que, lors de la phase d'attachement, le matériel contenu dans les hétérosomes se vide dans les canaux collecteurs et se mélange dans la rosette, puis, grâce au podite, est appliqué sur la branchie où il forme le pied ou style du futur adulte. L'appareil de fixation de l'adulte comprend donc deux parties de nature différentes: le pseudostyle, c'est-à-dire la région postérieure du corps cellulaire, et le style, une sécrétion extracellulaire. Celui-ci forme une masse tronconique intimement fixée au substrat. Sur sa face supérieure, le style porte 16–18 stylonèmes enserrés dans les cryptes de la rosette pseudostylaire. Celle-ci correspond à la rosette larvaire, et les cryptes communiquent avec une chambre et des acini suprastylaires, eux-mêmes vestiges des canaux collecteurs larvaires. A quelques détails près, il semble bien que l'appareil de fixation des Chonotriches actuellement étudiés soit construit sur le même type. Cet appareil de fixation est différent de celui des Suctoria et des Peritricha; il présente peut-être quelques similitudes avec le complexe “bouche-rosette” des Apostomatida. Enfin, la présence d'un podite chez une larve de Chonotriche est un argument nouveau en faveur du rapprochement Chonotrichida–Dysteriidae.

Notes: During excystment of an amoeba, Cochliopodium sp., scale formation was examined with light and electron microscopy. This amoeba was covered with scales. When the amoeba encysted, the scales remained on the external surface of the cyst wall. Soon after the induction of excystment the Golgi complex began to develop. Many vesicles were extruded from it and changed into vacuoles. Scales were observed first in the vacuole adjacent to the Golgi complex and later in inside the cyst wall. When the amoeba excysted it had been coated by the newly formed scales. It is suggested that the scale formation is dependent on the activity of the Golgi complex.

Notes: The infection of bovine embryo skin and muscle cells by trypomastigotes of four Trypanosoma cruzi clones (CA-I/71, /72, Miranda/76, /80) was quantified. Stable and reproducible intra-isolate differences were observed; an almost 70-fold difference in infectivity occurred between clones. The CA-I/71 clone was not susceptible to N-acetyl-D-glucosamine at a concentration that inhibits the infection of vertebrate cells by Ernestina and Y-strain parasites. Eight other monosaccharides that are common constitutents of vertebrate cell surface glycoproteins also failed to inhibit the infection of vertebrate cells by the CA-I/71 clone.

Notes: Scanning electron microscopy confirmed our previous finding that toxoplasmas actively invade mouse peritoneal cells that are inhibited from phagocytosis. The parasites entered cells with the conoid end first and sometimes showed a counter-clockwise torsion of the body during invasion. Counter-clockwise torsion was also noted in free toxoplasmas. Host-cell responses to active invasion varied with experimental conditions and with the type of host cell. Under adverse culture conditions for phagocytosis, normal macrophages formed rudimentary filopodia or lamellipodia around the tips of in vading toxoplasmas; macrophages subjected to hyperthermia before similar incubation with toxoplasmas showed little or no response to invasion. Normal and heat-treated lymphocytes showed little surface reaction to invasion, but occa ionally a flocculent collar was seen around the tip of an invading toxoplasma. Scanning electron microscopy provides clues to possil'e mechanisms of toxoplasma locomotion and host-cell invasion.

Notes: The potential utility of protein arrays visualized by SDS-PAGE in taxonomic studies of protozoa has been investigated within the genus Tetrahymena. Matching coefficients have been obtained from one-dimensional separations of cytoskeletal proteins in a study involving 40 strains of Tetrahymena. In separate studies, the method was estimated to be accurate to within 10%, and the limit of intraspecific variation within the genus was estimated at ≅ 30%. Accordingly, it is suggested that strains showing matching coefficients 0.6 in these preparations probably represent different species. Further tests using strains identified to species by breeding criteria have shown that the 0.6 rule is asymmetric, i.e. although matching coefficients lower than this indicate separate species, values higher than this do not prove identity. Protein comparisons included in the present study indicate that strain Tur, previously identified as a strain of T. vorax, is distinct from all other macrostome-forming species. It is here designated Tetrahymena leucophrys n. sp.

Notes: Trypanosoma hydrae from the broad-banded watersnake, Nerodia fasciata confluens, underwent development in the freshwater leech, Placobdella parasitica. Epimastigotes and transitional stages were present only in the crop and gastric caecum. Only one metacyclic form was observed. The potential of leeches as vectors is discussed.Two broad-banded watersnakes were infected by inoculation with culture forms of T. hydrae maintained on NNN medium. Parasitemias varied from 105/ml to 106/ml with dividing forms seen only rarely. A broad and a slender form of T. hydrae are described from the peripheral blood of a watersnake 7 months after an experimental infection.

Notes: Goodwin, B. C., Holder, N. & Wylie, C. C., eds. 1983. Development and Evolution

Notes: Variant surface glycoproteins (VSG) of Trypanosoma brucei are released in a water soluble form on impairment of membrane integrity. We have previously shown that this release is the result of an enzyme-mediated event which converts the hydrophobic membrane form VSG into the hydrophilic water-soluble form. We now present further details of the methods by which membrane form VSG (mfVSG) may be isolated, uncontaminated by water-soluble VSG (sVSG). The sensitivity to different metal ions of the enzyme that mediated the conversion event is discussed, and some biochemical characteristics of different mfVSG preparations are presented.

Notes: Burenella dimorpha, a microsporidian parasite of the tropical fire ant, Solenopsis geminata, produces two morphologically distinct types of spores. The binucleate free spores (spores not bound by a pansporoblast membrane) develop normally at temperatures at least as low as 20°C and as high as 32°C. The uninucleate octospores (spores bound in octets by a pansporoblast membrane), however, develop in a restricted range of temperature. Octospores constituted 35.9%± 2.6 of the spores in 25 pupae held at 28°C. Raising the temperature to 30°C reduced octospores to 〈 1% of the total spore population. Lowering the temperature to 25° or 22°C reduced the octospore population to 8.5%± 6.5 or 0.4 ± 0.5, respectively. Inhibition of octospore development was complete at 20°C. In contrast, the octospores of Vairimorpha necatrix and Vairimorpha plodiae are reported to be abundant at 16°C and 21°C, respectively. The critical event blocked in octospore development may be meiosis, as evidenced by an abundance of binucleate sporonts in the octospore sequence of development, and absence of more advanced sporogonic stages in hosts held at inhibitory temperatures. Free spore size is not affected by temperature although yield may be slightly reduced at elevated temperature.

Notes: Fine-structural alterations in Trypanosoma rhodesiense trypomastigotes exposed to WR 163577, a prophylactic agent against animal African trypanosomiasis, were determined from cells grown in vitro. Exposure of trypomastigotes to a low concentration of drug resulted only in condensation of kinetoplast DNA fibrils. Exposure to higher drug concentrations caused clumping of nuclear chromatin and of cytoplasmic contents. Although alteration of kinetoplast DNA is the first detectable drug-induced change, the function of the kinetoplast in mammalian forms of African trypanosomes is unclear, and the secondary changes in the nucleus and cytoplasm may constitute the functionally significant alterations caused by WR 163577.

Notes: Sporozoites of Leucocytozoon caulleryi were inoculated into specific-pathogen-free (SPF) chickens intravenously. Fourteen days after inoculation, the infected blood, parasitized with second generation merozoites, was collected from the chickens. The blood was then suspended in SPF chicken serum or RPMI-1640 culture medium supplemented with 20% SPF chicken serum in petri dishes, which were cultured at 37°C or 41°C in a humidified atmosphere of 5% CO2. Second generation merozoites in parasitized, immature erythrocytes developed continuously through several substages and finally became micro- and macro-gametocytes after 6 days of incubation.

Notes: . A new species of malaria parasite, Plasmodium (Sauramoeba) heischi, is described from African skinks (Mabuya striata). Eleven individuals of 90 specimens collected in Nairobi were found to be infected. The new parasite is a large species, characterized by spindle-shaped gametocytes, the female often with a subterminal nucleus. The schizonts produce up to 65 nuclei and cause great hypertrophy and distortion of the host cell. Although similar to P. (Sauramoeba) giganteum in dimensions and merozoite numbers, P. heischi is easily distinguished by gametocyte and schizont shapes.

Notes: . Two persisting stages in the life cycle of a hemogregarine Karyolysus sp. are described from the liver and blood cells of its intermediate host, the lizard Lacerta raddei nairensis. The tissue cell merozoites lie in a parasitophorous vacuole. Despite the protective role of the vacuolar membrane, the intracellular parasites are progressively destroyed and eliminated during the autumn and winter. Some of the merozoites that normally survive within the host cell even in cold seasons appear to be surrounded by another type of parasitophorous vacuole which is connected to the intercellular space by narrow channels. The intraerythrocytic gamonts that persist in the circulating blood are encapsulated and undergo progressive, obvious structural changes. The two persisting stages are compared with hypnozoites of other Sporozoa.

Notes: . The blastogenic effects of specific parasite antigen and of mitogens on the lymphocytes of chickens infected with Eimeria tenella were examined. Lymphocytes from infected chickens were stimulated to divide when cultured with parasite antigen, but their responses to the T-cell mitogen, phytohemagglutinin (PHA), were depressed throughout the period of infection. Responses to the B-cell mitogen, lipopolysaccharide (LPS), were depressed during the first week of infection but enhanced in the second week. The inclusion of plasma samples from infected chickens in the culture medium depressed the responses of normal spleen lymphocytes to PHA, suggesting that soluble suppressor factors are generated during infection.

Notes: . Pathological changes and immunity induced by Eimeria vermiformis (Ernst, Chobotar & Hammond, 1971) were studied in outbred Swiss mice inoculated with 5000, 10,000, 20,000, or 40,000 oocysts. Cross immunity to E. ferrisi was also studied. In the case of E. vermiformis, mortality was dose dependent; most deaths were observed in the intermediate-dose groups. Most deaths also correlated with peak oocyst output. Histopathologic changes consisted of an early neutrophil and mononuclear cell infiltration in the small intestine. Later, villus atrophy and crypt hyperplasia caused a decrease in the villus-crypt ratio. During the acute phase (8-10 days after inoculation), villus tips were eroded and parasites with necrotic debris filled the cryptal and intestinal lumina. Vacuolar changes were observed in epithelial cells of the small intestine. Neither parasites nor significant pathological changes were observed in extra-intestinal organs. Mice were totally immune to reinfection with E. vermiformis 30 and 105 days after inoculation. Cross immunity was not observed between E. vermiformis and E. ferrisi.

Notes: . Plankton and fishes are abundant in Antarctic waters. Benthic invertebrates and fishes of the continental shelf are well-known, but the abyssal benthos below the highly productive open ocean is largely unsampled. The fishes are adapted (with antifreeze properties) to temperatures that are often or always below the freezing points of their body fluids. All the major groups of helminth parasites are found in or on these fishes. The few records of protozoa include Cryptobia, haemogregarines, a monoflagellate, the myxosporan Neoparvicapsula, and (in this paper) Ceratomyxa. Myxidium, Zschokkella, and a coccidian. Most of the protozoa were obtained from nototheniid fishes. No protozoa and few, if any, other parasites were recovered from 173 midwater fishes collected from outside of the continental shelf. Differences in infections in different localities and depths are due to many ecologic factors needing much more study of their relations to parasitism. These factors include temperatures, salinities, densities of fish populations, food and feeding habits, migrations of adult and immature fishes, availability of potential intermediate hosts, and marine “snow.”

Notes: . A new species of Eimeria from the fat-tailed gecko Hemidactylus brookei in Gambia, West Africa, was described and named E. helenae in honor of Mrs. Helen Levine. The oocysts averaged 22.2 μm and each contained four sporocysts (8.0 × 6.9 μm) with two sporozoites per sporocyst. No schizogony or gametogony was discovered in the intestine, suggesting that these stages may occur in the liver or bile cannuli. The oocysts of an adeleid parasite of the insect prey of the centipede Scolopendrium morsitans were described. Plasmodium agamae, an eimeriid hemogregarine, Pirhaemocyton, and a Shellackia-type parasite were found in the blood of agamid lizards. The fruit bat Epomorphorus gambianus was commonly and heavily infected with Hepatocystis epomorphori.

Notes: . Sarcocystis-like oocysts-sporocysts were found in four species of owls (Asio otus, Bubo bubo, Strix aluco, and Tyto alba) and in five species of predatory birds (Accipiter gentilis, Accipiter nisus, Buteo buteo. Circus aeruginosus, Falco tinnunculus). In addition, the muscles of 15 of 41 (36.5%) pheasants (Phasianus colchicus) and one of two jays (Garrulus glandarius) were found to harbor three types of Sarcocystis. Three of 15 (20%) infected pheasants had type I cystozoites (6-8 × 2 fim) in muscle homogenates, but sarcocysts were not seen whereas the other 12 infected pheasants had type II cystozoites (16 × 2-3 pm) and sarcocysts (90 × 600 μm) in their muscles. The one infected jay had type III cystozoites (8-10.5 × 2.5-3 μm) and sarcocysts (35-40 × 〉770 μm) in its muscles.

Notes: Ultrastructural investigations of P. falciparum cultivated in vitro in human erythrocytes revealed new features of the feeding mechanism of the parasite. Mature trophozoites and schizonts take up a portion of the host cytosol by endocytosis which is restricted to cytostomes and which involves the invagination of both parasitophorous and parasite membranes. The resulting endocytic vesicles, surrounded by two concentric membranes, migrate towards the central food vacuole membrane. The external membrane of the endocytic vesicles apposes that of the food vacuole, leading to the internalization of vesicles bounded by a single membrane into the vacuolar space where they are rapidly degraded. We conclude from this sequence of events that endocytic vesicles fuse with the food vacuole. Treatment of infected cells with therapeutic concentrations of chloroquine inhibited the last step of the feeding process, i.e. vacuolar degradation. This was manifested by the accumulation within the vacuolar space of intact vesicles bounded by single membranes. The implications of these findings for the antimalarial activity of chloroquine are discussed.

Notes: The large cytopharyngeal pouch of the macrostomal form of Tetrahymena vorax, following the addition of calcium, can form a sealed, empty vacuole. The open cytostomal region of this cell, which averages about 16 μ in diameter, is closed by an upward (ventral) movement of the right and posterior ribbed walls, both of which project into the cytostomal cavity. At the same time, the anterior and left walls of the cytostome-cytopharyngeal complex move to the right, forming a diagonally (right to left) placed furrow in the floor of the buccal cavity as these walls meet. As a result of the movement, the edges of the single membrane-bounded cytopharyngeal pouch are brought together and fuse, producing the closed vacuole. Elements of the cytoskeleton appear to participate in the closure process. Three major groups of ribbed wall microtubules support the open cytostome. The anterior ribbed wall microtubules pass laterally along the anterior (dorsal) portion of the cytopharyngeal pouch to the left where they end in the specialized cytoplasm. Middle oral rib microtubules terminate at the right and posterior margin of the cytopharynx while microtubules from the most posterior region of the ribbed wall pass to the left terminating in the specialized cytoplasm. The fine filamentous reticulum, a striated reticulum that borders the right, posterior, and anterior margins of the cytostome-cytopharyngeal complex, is in an ideal position to participate in these movements. It is anchored anteriorly high up in the buccal cavity to the cross-connective between the third membranelle and the undulating membrane complex. It courses beneath the right and posterior ribbed walls and runs laterally along the anterior margin of the cytopharynx to the left side. Contraction or pulling of this reticulum would act to bring the microtubule-reinforced walls of the cytopharynx together permitting fusion of the cytopharyngeal pouch membranes to form a sealed vacuole.

Notes: The ultrastructure of the sexual stages of Plasmodium gallinaceum during gametogenesis, fertilization, and early zygote transformation is described. New observations are made regarding the parasitophorous vacuole (PV) of gametocytes and the process of emergence in male and female gametocytes. Whereas female gametocytes readily disrupted both the PV membrane and host cell plasmalemma during emergence, male gametocytes frequently failed to break down the plasmalemma of the host cell. New observations and hypotheses are presented on the behavior of the male gamete nucleus. Following fertilization, the male nucleus appears to travel through a channel of endoplasmic reticulum in the female gamete before fusing with the female nucleus at a region in which the nuclear envelope is thrown into extensive convoluted folds. Polarization of the zygote nucleus, in association with the appearance of a perinuclear spindle of cytoplasmic microtubules, preceded all other changes in the developing zygote. After nuclear polarization becomes apparent, electron-dense material is deposited beneath the zygote pellicle, and a canopy is formed which eventually extends over the entire apical end of the developing ookinete. As the apical end begins to extend outward, polar rings, micronemes, and subpellicular microtubules become visible in this portion and a “virus-like” inclusion known as a crystalloid is formed in the posterior portion of the zygote. When female gametes are prevented from being fertilized, the cytoplasm at 24 h after gametogenesis is devoid of most of those organelles found in the developing zygote or the mature ookinete. The cell is surrounded only by a single membrane. Although at various points beneath the membrane there are deposits of electron-dense material reminiscent of those deposited in the zygote, no further development of ookinete structures takes place in the unfertilized female gamete.

Notes: The somatic and oral cortical ultrastructure of the plagiopylid ciliates Lechriopyla mystax Lynch, 1930 and Plagiopyla minuta Powers, 1933 are described. The somatic kinetids are monokinetids with an anteriorly directed kinetodesmal fibril originating near triplets 5, 6, 7, a divergent postciliary ribbon originating at triplet 9, and an unusual transverse ribbon originating in dense material adjacent to triplets 1, 2, 3. The transverse ribbon extends beneath the right surface of the cortical ridge adjacent to the kinety from which it originated. The oral kinetids are also monokinetids from whose base rootlet fibrils extend inwards beneath the oral kineties and converge on the furcula. The striated band on these ciliates is composed of a series of short ridges orthogonal to the longitudinal axis of the band. The sides of the striated band groove are apparently supported by macrotubules. The cortical ultrastructure of the plagiopylids is discussed with reference both to the optical microscopy of the organisms and to the ultrastructure of other ciliate taxa. The plagiopylids are not clearly related to any other higher taxon and are placed incertae sedis in the Subphylum Cyrtophora Small, 1976.

Notes: The colonization, distribution, population density, and species diversity of amoebae on leaves of Oak Leaf lettuce, Lactuca sativa var. crispa, and Boston lettuce, L. sativa var. capitata, were investigated. The role of soil in the colonization of Oak Leaf lettuce was determined by comparing numbers of amoebae present on basal leaves (those that pass through soil) with numbers on wrapped leaves (those that do not pass through soil). Amoebae were present in ten samples of basal leaves and ranged from 154–1510/g of leaf tissue. Wrapped leaves failed to yield amoebae in seven of ten trials and contained 〈4 amoebae/g of tissue. Mean values for the population density of amoebae on Oak Leaf basal leaves and Boston lettuce leaves were 484 ± 133 and 453 ± 93, respectively. The distribution of amoebae on green and white parts of leaves from both kinds of lettuce was studied. The occurrence of amoebae on rinsed, unrinsed, visibly clean, and visibly dirty samples of Boston lettuce leaves was established.

Notes: Primary productivity, chlorophyll a, phosphorus and nitrogen nutrients, and other chemical and physical parameters were measured in 13 wetland lakes in northern lower Michigan. These lakes included several examples located in each of the four major wetland types—bogs, fens, marshes, and swamps. Of the four types, the brown-colored waters of the acid bog lakes generally had the highest levels of primary productivity, chlorophyll a, phosphorus, and nitrogen. Primary productivity correlated positively with water color, total-N, and NH3-N (α≤ 0.05). By these measures, waters of the bogs were the most eutrophic of the four types of wetland lakes. These findings would seem to contradict the generally-held concept that “dystrophic” bog lakes are extremely oligotrophic.Protozoan colonization of artificial substrate islands was monitored at each wetland site. The correlation between protozoan colonization rates (G values in the MacArthur-Wilson noninteractive model) and primary productivity, measured by 24-h light and dark bottle incubations, was significant at the 95% confidence level (r= 0.850, P= 0.001) and with water color at the 90% confidence level (r= 0.599, P= 0.084). It was concluded that protozoan colonization rate was an excellent indicator of the trophic status of wetland lakes.

Notes: Amastigotes of different strains of Trypanosoma cruzi responded to stimulation with concanavalin A in an axenic medium by increased DNA synthesis and cell multiplication. These effects were inhibited by α-methyl mannoside. Other mitogens, i.e. phytohemagglutinin P, castor bean ricin Type II isolated from Ricinus communis, and a bacterial lipopolysaccharide, had no effect on amastigote growth. Amastigote stimulation by concanavlin A lends itself to studies on the biochemistry and cell cycle of this human pathogen.

Notes: Spores of Nosema algerae Vávra & Undeen were exposed to 5 to 3000 KR of gamma radiation, then assayed for viability in Anopheles quadrimaculatus Say, and tested for germination in vitro. There was a dosage-dependent loss of viability between 5 and 100 KR. Immediately after exposure to radiation at dosages between 1000 and 3000 KR, the spores progressively lost ability to germinate in 0.2 M KCl, pH 9.5. Between 250 and 1000 KR spores germinated well immediately after irradiation but, over a time span of days, fewer spores were able to germinate. Gamma radiation at 1000 and 2500 also caused a decrease in intrasporal trehalose concentration. The decline in percentage germination and trehalose concentration was more rapid at the higher dosages than the lower dosages.