ALBERT

Notizen: SYNOPSIS Nosema algerae, a microsporidan parasite of anopheline mosquitoes, was successfully replicated in 3 insect cell culture lines: Trichoplusia ni (TN-368); Heliothis zea (IPLB-1075); and Mamestra brassicae (IZD-Mb-0503). Infectious spores were produced in vitro. Spores were observed at 48 h postinfection, and some cells were filled with sproes by 72 h.The number of parasites per cell increased with time. At 72 h postinfection, the infection rates for the 3 cell lines ranged from 23 to 32%. Infected cell lines were subcultured, and by the 6th passage spore production had ceased.

Notizen: The somatic and oral ultrastructures of Woodruffia metabolica Johnson & Larson are described. the somatic kinetids are dikinetids, with the anterior kinetosome often not ciliated. A transverse ribbon of microtubules and a single postciliary microtubule are associated with the anterior kinetosome. A transverse ribbon, postciliary ribbon and kinetodesmal fibril are linked with the posterior kinetosome. the posterior transverse ribbons extend posteriad, to the left of the Kinety, joining more anteriorly originating transverse ribbons in a compound LKm fiber. These features together with interkinetosomal linkages relate Woodruffia to other members of the order Colpodida.

Notizen: Developmental stages of Eimeria meleagrimitis Tyzzer were found throughout the intestine and ceca of turkeys given inocula ranging from 104 to 7.5 × 105 sporulated oocysts/bird. Infection initially occurred in the duodenum and upper jejunum but later moved down the intestine and into the ceca. the speed with which the infection moved into these areas was roughly proportional to the inoculum size. Heaviest infections were in the ileum, neck of the cecum, and large intestine. the life cycle consisted of 5 asexual generations before gametogony, a 6th asexual generation developing simultaneously with gametogony. First- and 2nd-generations were located along the sides of villi in the upper intestine rather than in the crypts of Lieberkühn, as previously described in England for this species. Transitory first-generation stages that were abnormally large and usually degenerate were found in the neck of the cecum.

Notizen: Galactosephilic and mannosephilic lectins from Pseudomonas aeruginosa interact with Tetrahymena pyriformis GL. Specific adsorption of these lectins onto the Tetrahymena can be shown by inhibition of hemagglutination and by peroxidase binding to the cells mediated by the mannosephilic lectins. Interaction with the lectins does not agglutinate the protozoa even after immobilization by Na fluoride, formaldehyde, and glutaraldehyde or after papain treatment. However, inclusion of the lectins in the growth medium increases the growth rate of Tetrahymena and their presence in the medium supplied to starved ciliates increases phagocytosis of Chinese ink and vacuolization.

Notizen: SYNOPSIS. Dipodomys merriami Mearns and Dipodomys ordi Woodhouse were surveyed for coccidia in El Paso County, Texas. Infections with Eimeria chobotari. Eimeria dipodomysis and Eimeria balphae were 24.8%. 4.4%, and 11%, respectively, for D. ordi. Dipodomys merriami had an infection level of 23.8% with E. chobotari. Four animals concurrently harbored E. chobotari and E. balphae or E. dipodomysis or a new species Eimeria chihuahuaensis. Male and female host infection levels were not significantly different. The new species is described and photographs of 3 previously described Eimeria from Dipodomys are presented.

Notizen: SYNOPSIS. Experimentally induced precystic stages and mature cysts from 3 clones of Tetrahymena rostrata were examined by light and electron microscopy. It was demonstrated by cytochemical staining and fine-structural observations that precystic stages release mucocyst material that provides for the production of a cyst wall. Early and late cysts also contain numerous autophagous vacuoles. In late cysts there is a replacement of depleted mucocyst organelles. The developmental evidence obtained from sampling of sequential developmental stages suggests an ∼24-h timetable of cytoplasmic events associated with encystment in this organism.

Notizen: SYNOPSIS. Filamentous cyanobacteria are ingested through the cytopharynx of the ciliate Pseudomicrothorax dubius. The cytopharynx is a complex of microtubules and microfilaments located in a highly vesiculated cytoplasm, the phagoplasm. Two types of membrane-bounded phagoplasmic vesicles can be distinguished by their differences in size, fine structure, and acid phosphatase (AcPase) content. One type has a homogeneous, electron-dense interior which is AcPase-positive. These vesicles are present in fed cells and in unfed cells devoid of food vacuoles, and thus appear to be primary lysosomes. During phagocytosis, exocytosis within the cytopharynx of the primary lysosomes results in the elaboration of a food vacuole. The vacuole grows by incorporation of lysosomal membrane; lysosomal hydrolases are liberated into the vacuole. Within less than 1 second of AcPase's entry into the food vacuole, it is detectable within the cyanobacterial cytoplasm, and within 5 seconds, destruction of the cyanobacterial filament is observed. It is hypothesized that the rapidity of hydrolase penetration of the cyanobacterial cell wall is the result of the action of molecules analogous to the “killing agents” of neutrophil leukocytes, which rapidly render bacterial envelopes permeable. AcPase, and presumably other hydrolases, are present in the cyanobacterial filament when filament destruction occurs; they thus appear implicated in this process. Hydrolases may activate an autodestruction mechanism in the cyanobacterium. Firm adherence of the food vacuole membrane to the cyanobacterial filament is demonstrated, and its role in phagocytosis is discussed.

Notizen: SYNOPSIS. The surface membrane potentials of suctorian genus Heliophrya were studied with intracellular electrodes. Resting membrane potentials averaged -32 mV, and spontaneous depolarizing potentials occurring at apparently random intervals and having a variety of waveforms were routinely observed. Such spontaneous potentials were correlated in time with visually monitored contractile vacuole activity. Individual contractile vacuoles had unique, although somewhat variable, electrical signatures. In the presence of an intracellular electrode all vacuoles contracted independently, but at approximately the same frequency. The amplitude of the electrical potentials increased when the membrane was hyperpolarized and decreased when it was depolarized. The sign of such potentials reversed at between -10 mV and the zero membrane potential. A 20% decrease in the membrane resistance was measured at the peak of the spontaneous depolarizing potentials.

Notizen: SYNOPSIS. Female golden hamsters, either in the last week of pregnancy or in the first weeks of nursing, excreted in their feces variable numbers of pseudocysts of Tritrichomonas muris. Pseudocysts examined by electron microscopy had internalization of the 3 anterior flagella and the undulating membrane with its recurrent flagellum. The undulating membrane and the associated marginal lamellae were characteristic of T. muris. Pseudocysts gradually become motile after 2 or more hours of incubation in medium. The “excysted” trophozoites were identified ultrastructurally as T. muris. Newborn hamsters were not infected with T. muris at 3 days of age, but by the 7th day essentially all were found to have infected ceca, concomitant with cecal enlargement and the appearance of adult-type feces.

Notizen: SYNOPSIS. Mating-type dependent cell pairing in Oxytricha hymenostoma was studied by both light autoradiography and transmission electron microscopy. The process results in the macronuclear bodies of the 2 partners fusing completely with each other 2 by 2. In each fusion the 2 chromatin masses, easily distinguishable from each other for the first 6 h of the pairing, progressively intermingled and underwent a sort of rearrangement so that they eventually acquired a uniform pattern. The possible mechanisms regulating macronuclear fusion and DNA amount in the daughter cells are discussed.

Notizen: SYNOPSIS. Trypanosoma (Schizotrypanum) cruzi clones were derived from isolates of an acute human case of Chagas' disease (strain Esmereldo), a human case of T. cruzi infection (strain CAN-III) and from a naturally infected opossum (strain WA-250). The isoenzyme patterns and growth rates of the clones were stable during long-term cultivation, by serial passages, of the parasites in liquid medium. Both clones of strain Esmereldo were zymodeme II; the 2 clones of strain CAN-III, zymodeme III; and the 5 clones of strain WA-250, zymodeme I. The range in doubling times of the parasite populations in liquid medium were 36–49. 7 h (strain WA-250), 117.2–133.7 h (Esmereldo clones) and 169–208 h (CAN-III clones).

Notizen: SYNOPSIS. Under aerobic conditions, we have determined glycerol uptake in the long slender (LS) bloodstream form of Trypanosoma (Trypanozoon) brucei brucei by studying glycerophosphate accumulation in the parasites. The coupled enzyme theory applies to the permeation-phosphorylation sequence. Glycerol passage through the plasma membrane is asymmetric, the efflux process being favored over the influx process. No free diffusion of glycerol can be detected even under conditions under which free glycerol accumulates within the cells; most probably, glycerol permeation is mediated by a specific transport system. In the absence of respiratory activities, glycerol is known to be an end-product of T. brucei glycolysis; its production from glycerophosphate should allow ATP synthesis. The observed efflux of free glycerol following intracellular accumulation of glycerophosphate confirms the hypothesis that glycerol production occurs through reversal of glycerol kinase activity.We conclude that in vivo the role of the carrier-mediated asymmetric permeation process is to prevent inhibition of the reversal of the glycerol kinase-mediated reaction by removing free glycerol.

Notizen: SYNOPSIS. the following species are described from Hawaiian birds: Isospora brayi sp. n., with oocysts 27 × 26 μm and sporocysts 19 × 12 μm, from the Japanese white-eye. Zosterops japonicus Temminck & Schlegel; Isospora cardinalis sp. n., with oocysts 24 × 23 μm, and sporocysts 16 × 10 μm, from the cardinal, Cardinalis cardinalis (Linnaeus); Isospora ivensae sp. n., with oocysts 26 × 25 μm, and sporocysts 18 × 12 μm, from the spotted or white-throated munia, Lonchura punctulata (Linnaeus); Isospora loxopis sp. n., with oocysts 26 × 23 μm, and sporocysts 16 × 13 μm, from the amakihi or honeycreeper, Loxops virens (Gmelin); and Isospora phaeornis sp. n., with oocysts 27 × 19 μm, and sporocysts 16 × 11 μm, from the omao or Hawaiian thrush, Phaeornis obscurus (Gmelin). All the host birds belong to the order Passerorida.

Notizen: SYNOPSIS. Equine protozoal myeloencephalitis (EPM) was diagnosed in 10 horses. By electron microscopy, schizonts were found in intact host cells of the spinal cords or, more frequently, free in the extracellular spaces. Developmental stages of schizonts differed morphologically, and the late stage of schizogony was characterized by endopolygeny. These findings permitted tentative identification of the protozoon as a Sarcocystis sp. Free merozoites were present in the extracellular spaces or in cells of the spinal cord. Pericytes of capillaries were most frequently parasitized by merozoites, but the cytoplasm of neurons, macrophages, intravascular and tissue neutrophils, and axons of myelinated nerve fibers also contained these organisms. the presence of parasites in the cytoplasm of tissue and circulating neutrophils suggests that this putative Sarcocystis sp. may have a hematogenous phase of infection.

Notizen: SYNOPSIS. 20-Methylcholanthrene induced cyst formation in Nyctotheroides puytoraci when injected into its host Bufo regularis. Presumably this hydrocarbon or its metabolites reaches the parasites in the recta of treated host animals and induces encystment. However, injection of B. regularis with 0.5 mg of 20-methylcholanthrene + vitamin A palmitate (5,000 IU) inhibited the hydrocarbon-induced encystment of the parasites.

Notizen: SYNOPSIS. Simple media for Tetrahymena, using rat gut or soybean as the nutrient source are described. Cultures can be maintained in these media up to one year at room temperature.

Notizen: SYNOPSIS. A mutant of Tetrahymena thermophila. “pig,” excretes melanin precursors into the culture medium where spontaneous polymerization to melanin occurs. the precursors, probably oxidation products of catecholamines. are produced in large amounts by the mutant by decarboxylation of tyrosine and hydroxylation of the resulting tyramine. Overproduction and excretion of precursors by the mutant appears to result from elevated specific activity of L-aromatic amino acid decarboxylase (DOPA decarboxylase) (E.C. 4.1.1.26).

Notizen: SYNOPSIS. Paramecium multimicronucleatum has been cultured for 20 years on a medium of salts, vitamins, amino acids, fatty acids, ribosides, and stigmasterol plus a little nondialyzable fraction (NDF) of baker's yeast. Fractionations of NDF identified 2 essentials: (a) in a fraction 〈 100,000 daltons which contained much protein and replaceable by ovalbumin and (b) in a fraction of 〈 300,000 daltons; this fraction contained much polysaccharide, replaceable by glycogen, which is 〉 300,000 daltons. For 2 years now P. multimicronucleatum has grown well with ovalbumin and glycogen replacing NDF. Besides ovalbumin, concanavalin A satisfies the protein requirement; this lectin attaches to sugar residues in glycogen. Studies with a fluorescent dye, PGA-1A, a stilbene derivative, provides further evidence for the polysaccharide requirement. This dye attaches to polysaccharides; when added to glycogen, and this in turn is added to a culture containing ovalbumin, fluorescent blue vacuoles appear within 2–3 h. When dye + glycogen were added to a culture without ovalbumin, no fluorescent vacuoles were found. A protein appears involved in formation of food vacuoles; this fits the pattern for endocytosis described in recent reviews. Besides glycogen, mannan gave good growth. Dextrin and amylopectin gave only fair growth through 7 serial transfers; glucose, maltose and amylose did not sustain growth. Strain 51 of P. tetratrelia, which grows well in NDF medium, grows well when NDF is replaced with ovalbumin and glycogen.

Notizen: Oocysts of Eimeria caprovina sp. n. from the domestic goat, Capra hircus, are ellipsoidal, subspherical or slightly ovoid, usually flattened at the micropylar end. They measure 29.7 (26-36) × 23.7 (23-28) μ. the sporocysts are elongate ovoids, measuring 14.3 (13-17) × 8.3 (8-9) μ. with Stieda bodies at the narrow ends. the oocyst wait is 1.6 μ thick, smooth, dark-brown to brownish-yellow, and 2-layered. A micropyle. 6.2 (4-10) μ in diameter, polar granule, and sporocyst residuum are present: micropylar cap and oocyst residuum are absent.

Notizen: Infective trypanosomes developed when Trypanosoma brucei was cultivated at 28 C in a liquid medium containing tsetse fly head-salivary gland explants. They were separated from the noninfective culture forms using DEAE-cellulose column chromatog-raphy. It was demonstrated by light and electron microscopy that the separated organisms were morphologically similar to metacyclic stages found in a tsetse fly and that they had a characteristic surface coat. Single metacyclic trypanosomes isolated from the cultures gave rise to infections in mice.

Notizen: Sporozoites of Plasmodium berghei and Plasmodium knowlesi, incubated in normal serum readily interact with peritoneal macrophages of mice or rhesus monkeys, respectively. Interiorization of the sporozoite requires that both serum and macrophages be obtained from an animal susceptible to infection by the malaria parasite. Serum requirements for sporozoite attachment to the macrophage are less specific. Phagocytosis is not essential for the parasites to become intracellular. Our findings indicate that active penetration of the sporozoites into the macrophages does occur.

Notizen: The uptake of [57Co]B13 (cyanocobalamin) by Euglena gracilis strain Z (ATCC 12716) occurred in 2 distinct phases-an initial rapid phase followed by a slower secondary phase. This secondary phase appeared after the saturation of the binding sites involved in the initial rapid phase and was energy-dependent and completely inhibited by 2,4-dinitrophenot, KCN and sodium azide. the subcellular localization of labeled cyanocobalamin taken up by the cell was mostly contained in the chloroplast fraction. the time course and the saturation kinetics of B12 uptake by purified chloroplast fraction indicated that this fraction and the intact cell had a similar affinity for the vitamin B12. This suggested that the chloroplasts contained the binding sites for vitamin 12 and might regulate the uptake process in the intact cell. the kinetic properties of the overall 12 uptake mechanism suggested that the initial phase represent the binding of vitamin 12 to the available sites on the chloroplast. the secondary phase may represent the de novo synthesis of new binding sites.

Notizen: SYNOPSIS Amebae isolated from sediments of the Atlantic Ocean and Gulf of Mexico were maintained in continuous culture and most were identified to genus and species. Twenty-six species representing 12 genera were recognized from existing literature and several others (Flabellula, Mastigamoeba, Cochliopododium) were identified only to genus. One ameboflagellate and several small limax-type amebae which require further study also were isolated. Other sarcodmids belonging to the Heliozoida, Testocida, Leptomyxida, and Proteomyxida were identified only tentatively. the distribution of the amebae and ameba-like organisms was tabulated for the following geographic areas: Atlantic Ocean near Long Island, New York: Atlantic Ocean 16-65 miles offshore from New York and New Jersey: Atlantic Ocean 1-50 miles offshore from Maryland and Delaware: and the Gulf of Mexico 3.5-41 miles offshore from the southeastern United States. Amebae present in shellfish holding trays at Lewis. Delaware, were isolated, and identified to compare the distribution of species in laboratory tanks with those present in natural ocean bottoms. Published accounts of each collection site were reviewed to obtain specific data on contamination with sewage wastes, acid wastes, dredge spoils, and petroleum hydrocarbons. Two previously undescribed amebae were found to represent new genera and species and are described herein, one from the Delaware mariculture facility, and the other from the digestive tract of the blue crab, Callinectes sapidus, and the gill surface of the lady crab, Ovalipes ocellatus. Sarcodinids present in clean or stressed environments were listed, and genera and species that were widespread or apparently geographically restricted were recorded.

Notizen: SYNOPSIS The galactosephilic and mannosephilic hemagglutinins of Pseudomonas aeruginosa adsorbed onto Euglena gracilis, Chlamydomonas reinhardi, and Tetrahymena pyriformis. Furthermore, peroxidase binding to the 3 protozoan species was shown to be mediated by these lectins. Binding of Pseudomonas lectins to E. gracilis and C. reinhardi caused their specific agglutination, whereas no agglutination was observed with T. pyriformis, even after treatment by papain or by NaF. Added to the culture medium, the Pseudomonas hemagglutinins stimulated growth of E. gracilis and T. pyriformis due to their binding to these protozoa: this effect was partly inhibited by the specific sugar.

Notizen: SYNOPSIS In the ciliate Euplotes crussus, doublet cells of 3 complementary mating types were mixed and multiconjugant complexesobtained. The cells were not uniform in the G, stage at the time of mixing. Despite asynchrony, the nuclear events of conjugationstarted and progressed coordinately in all the members of each complex, leading to a synchronous exchange of pronuclei. An adjustmentof the cellular timing takes place before the nuclei of multiconjugants begin dividing. This adjustment probably occurs through specificciliary contact during preconjugant interaction.

Notizen: SYNOPSIS Hydroxyurea (HU) concentrations above 50 μg/ml reversibly inhibited cell division of Trypanosoma brucei brucei stock STIB 366 procyclic culture forms, but not growth of individual cells. the volume of the nucleus and of the cytoplasm increased in the presence of the drug as did the percentage of cells with 2 kinetoplasts. Electron microscopy revelaed that the nuclear membrane was extended forming protrusions which surrounded areas of the cytoplasm. Replication of the kinetoplast DNA did not seem to be affected by HU. the uptake of [3H]thymidine increased in the presence of 25 μ/ml HU 3-fold compared to control cells. the nuclear volume and the dry weight of the culture forms increased proportionally to the amount of label incorporated.

Notizen: SYNOPSIS. Crosses between serine requiring and non-requiring clones from natural habitats give rise to progeny that are numerically equally distributed between the two categories. Most of the progeny from crosses between two serine requiring parental clones require serine with a few segregating out that do not need the amino acid. These data indicate that the gene or genes controlling the serine non-requirement are recessive to the wild type which requires serine. Growth of the F1 progeny was highly variable. Some clones failed to survive on serine deficient media and were therefore tentatively assigned the genotype +/+. The remaining clones were of two classes: one grew slowly on serine deficient media and was given the genotype of the heterozygote, +/s; the other grew without serine, hence was given the double recessive genotype, s/s. The F2 progeny from matings of s/s and s/s need no serine whereas the cross of +/s and s/s gave equal numbers of serine requiring and serine non-requiring progeny. The cross of two heterozygotes, +/s and +/s, yield progeny approximating the 3:1 ratio in favor of serine requiring clones. Crosses at the F3 level produced non-viable offspring in all cases except one. Progeny from this cross with the genotype s/s were mated giving rise to F4 progeny all of which grew without serine. The data support an outbreeding economy for this organism with selection in favor of the heterozygote. Although the data seem to favor a single-gene hypothysis, suppressor genes may be involved. With selection favoring the heterzygote, distorted genetic ratios make the data difficult to analyze.

Notizen: SYNOPSIS. Intracardial inoculation of 1–10 million L. donovani in 0.1 ml. of ground spleen suspension from an infected animal (hamster) results in a uniform rise of parasite numbers in the untreated animal over the first 8 days after the inoculation. This rise is highly consistent from experiment to experiment.Treatment is accomplished by parenteral injection of a compound for 6 successive days in this time interval, starting 24 hours after inoculation.No known active compound in proper dosage (sodium stibogluconate, pentamidine, fuadin) has failed to show a significant suppression of the expected rise in parasite numbers. No known inactive compound has had any effect on the course of the infection.The dosage-response curve for the active compounds suggests that the method is a sensitive one. Since it takes only 8 days to complete, it is economical as well.

Notizen: SYNOPSIS. It has been shown that the output of the contractile vacuole of Crithidia fasciculata increases as the concentration of solute in the external solution decreases when NaCl is the solute. The increase in output is the result of increased rate of growth as well as increased maximum size, the latter being more important in the range 0.1M–0.01M. Solutions of penta-erythritol produce the same effects as isosmolar solutions of NaCl. Body volume is not maintained constant but increases less than two-fold between 0.1M and 0.0001M. The isotonic concentration of NaCl is estimated as 0.12M. It is not possible to demonstrate any effect of concentration of the external environment on the endogenous rate of oxygen consumption. A linear relationship between output and calculated osmotic gradient across the cell membrane has been shown in the concentration range 0.1M–0.01M. Absence of this relationship, and failure of body volume to increase as predicted, in solutions more dilute than 0.01M are interpreted as indications that other processes probably become predominant in these solutions. It is concluded that the contractile vacuole of this flagellate is incapable of maintaining absolute constancy of internal osmotic pressure and body volume but prevents much of the change expected on physical grounds.

Notizen: SYNOPSIS. The rather rarely found holotrichous ciliate Pseudomicrothorax dubius, generally considered in the most authoritative literature to be a member of the order Trichostomatida, more likely belongs in the Hymenostomatida. Its curious combination of trans-ordinal characteristics, however, makes difficult exact systematic allocation of it and of the congeneric species P. agilis. The provocative morphological features include: a gymnostome-like cytopharyngeal “basket”; a tetrahymenal buccal apparatus, with membranelles comparable with those of primitive hymenostomes; an advanced semi-autonomous type of stomatogenesis; and sensory bristles, flattened rigid form, and restricted ciliature reminiscent of certain spirotrichs. Brief discussion is presented concerning the influence of modern ideas of ciliate classification upon what is considered the proper taxonomic position of the genus.

Notizen: SYNOPSIS. A new fresh water species of Actinosphaerium is described, the fourth member of the genus. Some of the more significant of its diagnostic traits are: 1) the Actinophrys-like nuclei with peripheral nucleolar granules and without central rosette-shaped nucleoli, 2) the occurrence of some nuclei in the ecto-endoplasmic border and the insertion of axial filaments on them, and 3) the low ratio of endoplasm to ectoplasm.

Notizen: SYNOPSIS. In cultures of the marine dinoflagellate Gonyaulax polyedra grown with alternating light and dark periods of 12 hours each, at least 85% of all cell divisions which occur in a day take place during a 5-hour period spanning the end of the dark period and the beginning of the light period. A very distinct maximum in the number of recently divided cells occurs at about the time the light period begins.This diurnal periodicity in cell division is lost after 4 to 6 days in continuous bright light, but will persist for at least 14 days in continuous dim light. The period of approximately 24 hours under constant conditions is only slightly altered by varying light intensity and temperature, both of which factors are known to affect markedly the generation time. The time at which cell division occurs is therefore postulated to be controlled by some sort of rhythmic or clock mechanism.Similarities between the cell division rhythm and the endogenous rhythm of luminescence in this organism are discussed. The occurrence of a glow, or steady light emission of low intensity, at about the time of cell division, is described, and it is suggested that this glow may result from cellular changes accompanying certain stages of cell division.

Notizen: SYNOPSIS. The photographs illustrate male and female gametes before fertilization, several progressive stages in the entrance of the male gamete into the cytoplasm of the female, cytoplasmic fusion of gametes, loss of extranuclear organelles of male gamete, retention of extranuclear organelles of female gamete, movement of pronucleus of male gamete to that of female, progressive stages in fusion of pronuclei, and the formation of the zygote which possesses the extranuclear organelles of the female gamete. Some abortive attempts at fertilization, resulting from failure of gametes to differentiate, are shown.

Notizen: SYNOPSIS. Detailed directions are given for the preparation of a simplified assay medium and of natural materials for assay of pteridines with Crithidia fasciculata. Unconjugated pteridines in natural materials which also contain conjugated pteridines (folic and folinic acids) can be assayed by destroying the conjugated pteridines with acid hydrolysis, which does not appreciably alter Crithidia-active unconjugated pteridines. The widespread occurrence of unconjugated pteridines and their significance in such processes as photoreception are discussed.

Notizen: SYNOPSIS. Photokinesis or the non-directed rate of swimming of Euglena gracilis for various light intensities was studied. The rate of swimming in white light was found to increase with light intensity until it reaches 0.16 mm./sec. at a saturation of 40 ft. candles, and then decreased with increasing light intensities. Polarized light appeared to be more effective (0.18 mm./sec. at 13 ft. candles) than non-polarized light.The action spectrum for photokinesis showed two peaks, a major one near 465 mμ, and another in the neighborhood of 630 mμ, having the values of 0.18 mm./sec. and 0.16 mm./sec. respectively at an intensity of 4 ft. candles.The action spectrum for phototaxis, or directed orientation, had a peak near 420 mμ and showed a maximum near 490 mμ. Both dark-grown and dark-adapted Euglena showed spectral peaks similar to those of the light-grown cells. For polarized light, the action spectrum had two additional peaks at 468 mμ and 508 mμ. The polarized light effect may indicate more than one light-absorbing pigment within the “eye spot” or that other pigments within Euglena were absorbing.

Notizen: SYNOPSIS. Four new species of Eimeria are described from small mammals in Liberia. These are: E. levinei, sp. nov. from a free-tailed bat, E. firestonei, sp. nov., and E. milleri, sp. nov., from a shrew, and E. putevelata, sp. nov., from a striped grass mouse.

Notizen: SYNOPSIS. A new species of Stentor is described, a fresh water form, medium sized, with cerulean blue pigment, and characterized by retractable feeding organelles.

Notizen: SYNOPSIS. Coprozoic protozoa from elk, bison, bear, moose, coyote, marmot, cattle, horse, sheep and man were kept in feces at 4° C. for 2–6 months. During that time in most of the samples there developed the flagellates Cercomonas sp., Copromonas ruminantium and Monas communis; the amoebae Vahlkampfia sp. and Sappinia diploidea, and ciliates of the Nyctotherus type, and an unidentified smaller species. There was a correlation between numbers of protozoa and bacteria. The same species of protozoa in soil or in soil mixed with boiled feces failed to live. Coprozoic protozoa may require certain essential metabolites from bacteria as do true parasites. The wide variation in appearance of cysts made it practically impossible to identify the protozoa with certainty in that stage. Reliance had to be on motile forms which readily developed in the cold cultures.

Notizen: SYNOPSIS. Mature macrogamonts were present in the small intestine of rats 5.5 to 7.5 days postinoculation with Eimeria nieschulzi oocysts; oocysts were present at 6 to 7.5 days. Types I and II wall-forming bodies in macrogamonts began to undergo ultrastructural changes within zygotes to form the outer and inner layers of the oocyst wall. Before and during oocyst wall formation a total of 5 membranes (M1–5) were formed at or near the surface of the zygote. The outer and inner oocyst wall layers formed between M2 and M3, and M4 and M5, respectively. The mature oocyst was loosely surrounded by M1 and M2, had an electron-dense outer layer, 100–275 nm thick, and an electron-lucent inner layer, 160–180 nm thick. It also contained an electron-lucent line consisting of M3 and M4 interposed between the outer and inner layers of the oocyst wall. The micropyle, measuring 935 × 47 nm, was located in the outer layer of the oocyst wall and consisted of 10–14 alternating layers of electron-dense and lucent material. The sporont of mature oocysts was covered by M5, immediately beneath which were M6 and M7. The sporont contained a nucleus and nucleolus, lipid and amylopectin bodies, mitochondria, ribosomes, as well as smooth and rough endoplasmic reticulum. Canaliculi, Golgi complexes, and types I and II wall-forming bodies were absent.

Notizen: SYNOPSIS. Pfeifferinella gugleri sp. n. was found in the liver of each of 2 land snails, Triodopsis albolabris (Say), in Iowa. The stages found, their average length × width dimensions (in μm), and their principal features were as follows: oocysts (21 × 14.5) ovoid, with micropyle and oocyst residuum; meronts (20 × 15) with 24–32 merozoites: microgametocytes (15 × 11.5) with many small microgametes; macrogametes (20 × 10.5) with 1–5 nucleoli and 1–2 wall-forming bodies, but without a “vaginal [fertilization] tube.” This tube, originally described by Léger & Hollande, 1912, from Pfeifferinella impudica, has since been considered a principal taxonomic feature of the family Pfeifferinellidae. In the absence of this structure, the taxonomic status of this monogeneric family is reexamined with the recommendation that the family be retained as distinct, but redefined to exclude the “vaginal tube” as a valid characteristic. The discovery of P. gugleri brings to 3 the number of pfeifferinellids reported, the other 2 being P. impudica Léger & Hollande, 1912, and P. ellipsoides Wasielewski, 1904, all from gastropods.

Notizen: SYNOPSIS. The effect of depletion and restoration of obligatory bacterial endosymbiotes on Amoeba proteus strain xD was studied. Removal of the symbiotes by culturing the amebae at 26.5 C resulted in loss of viability of the host cells, indicating that this strain is dependent on its endosymbiotes for survival. Amebae depleted of bacteria could initially be resuscitated by injection of isolated symbiotes, but prolonged deprivation led to irreversible changes. Nuclei of aposymbiotic amebae were viable when transplanted into the cytoplasm of normal cells, but the symbiote-depleted cytoplasm of heat-treated amebae could not be resuscitated by renucleation. No immediate ultrastructural changes were detected in aposymbiotic amebae except for clumping of nucleoli. Thus it appears that the symbiote performs an essential function as a cytoplasmic constituent.

Notizen: SYNOPSIS. A trypanosomatid with a choanomastigote stage and, therefore, belonging to the genus Crithidia, was isolated in culture from the alimentary tract of the hemipteran genus Zelus. the trypanosomatid was able to grow at 37 C, a characteristic reported to date from only 2 other members of Crithidia, C. hutneri and C. luciliae thermophila. Subsequently, the flagellate was cloned for biochemical studies which involved cleaving of kDNA by restriction endonucleases and analyses of the isoenzyme and histone patterns. In all the attributes revealed by the foregoing methods, the organism from Zelus differed from the latter 2 congeneric species. On these and morphologic grounds, this organism appears to belong in a new species for which the name Crithidia brasiliensis sp. n. is proposed.

Notizen: SYNOPSIS. Strains of 3 unnamed mating groups of the Tetrahymena pyriformis complex have been subjected to starch gel electrophoresis followed by staining the gels for the enzymes isocitrate dehydrogenase (NADP), tyrosine aminotransferase, and tetrazolium oxidase (superoxide dismutase). With respect to the electrophoretic mobilities of these enzyme systems, the mating groups referred to here as 5, 13 and 14 are very similar to Tetrahymena americanis (syngen 2), the most common North American species of the complex.Cultures in our collection labeled Tetrahymena cosmopolitans (formerly syngen 4) are either amicronucleate, with unique isozyme patterns, or micronucleate cells which mate with and have isozyme patterns similar to Tetrahymena canadensis (syngen 7). Immature progeny have been derived from crosses between the latter strains and T. canadensis recently collected in Colorado. The amicronucleate strains are now placed in the Tetrahymena sp. category, and we conclude that strains identifiable as T. cosmopolitanis are no longer available.The reliability of isozymes as characters in ciliate taxonomy was evaluated by comparing the present results for 3 enzymes in 15 groups of strains (syngens and phenosets) that had been compared in an earlier study. These enzyme systems gave correlation coefficients (r) of 0.75 or higher in the separate studies, and can be considered useful diagnostic traits. Other enzymes that were present at threshold levels of detectability or varied highly in concentration from species to species are too unreliable to be of diagnostic value. Some of the strains in the complex are so evolutionarily divergent at the molecular level that we have difficulty finding growth and electrophoretic conditions under which orthologous enzyme activities can be detected simultaneously for all the strains being compared.

Notizen: SYNOPSIS. With the aid of electron microprobe analysis on ciliate spreads, we detected zinc in ciliates and its accumulation in the endoplasm. A correlation was found between the amount of zinc accumulation and its concentration in the medium. By the same microprobe analysis of ultrathin sections, we determined semiquantitatively the zinc accumulation in the intracytoplasmic granules and its presence in macronuclei and in intra- and extracellular bacteria.

Notizen: SYNOPSIS. A Cryptobia sp. that appears to differ structurally from Cryptobia helicis Leidy occurred as 2 distinct populations within the spermatheca of the land snail Triadopsis multilineata (Say). Attached flagellates were a resident population within the spermatheca while pleomorphic, free-swimming forms were a transient population moving freely within the reproductive tract. Slender, free-swimming flagellates were apparently the ones transmitted by a venereal route. It was observed by electron microscopy that attachment was achieved through an extensive morphologic transformation of the first 5 to 10 μm of the anterior flagellum which resulted in the formation of numerous pseudopodium-like structures (“flagellapodia”) capable of invading the microvillus border of the host tissue. Flagellapodia were delimited by a single unit membrane, contained granular cytoplasm, and were long, branched, finger-like structures which interdigitated extensively with host cell microvilli. Fine structure of the Cryptobia sp. is distinctly different from that reported for C. helicis. the differences include structure and position of the preoral ridge, the cytostome-cytopharynx, the recurrent flagellum, and the presence of the flagellapodia.

Notizen: Eighteen domestic turkeys naturally infected with Leucocytozoon smithi Laveran & Lucet were maintained on restricted feeding schedules under conditions of either continuous light or natural light (light 13 h:darkness 11 h) photoperiods. Peripheral gametocyte numbers of L. smithi in all turkeys were determined every 2 h over a 36-h period. Peripheral gametocyte numbers of turkeys maintained under continuous light and restricted to either a 10-h feeding period (9:30 p.m. to 7:30 a.m.) once a day or a 2-h feeding period twice a day (7:30 a.m. to 9:30 a.m. and 7:30 p.m. to 9:30 p.m.) increased at or near the time of feed availability. Under natural photoperiod, gametocyte periodicity was not affected by restricting feed availability to the dark phase of the light-dark cycle. Mean parasite numbers were highest during the light phase when feed was not available, and lowest during the dark period when feed was accessible.

Notizen: Thirty newly excysted Spathidium spathula (Müller) and 60 newly excysted Spathidium muscicola (Kahl) were selected as progenitors of clonal daily reisolation lines that omitted both conjugation and encystment. Daily division rates were determined for each clone either until it died or until the end of the 170 days of reisolation. Both species had reduced fission rates as they accumulated fissions in the absence of macronuclear reorganization. Spathidium spathula had a significant reduction of daily fission rate after 100-120 fissions and S. muscicola after 20-30 fissions. Older clones of both species contained a noticeable proportion of abnormal organisms. A significant increase (10.5%) in daily fission rate occurred in aged sublines of S. spathula following conjugation (selfing) and its concomitant nuclear reorganization. Spathidium muscicota did not conjugate, but recently excysted sublines, compared to aged lines, had an increased daily fission rate.

Notizen: Mitochondrial DNA (mtDNA) from endosymbiote-free stocks of Paramecium tetraurelia was isolated by 2 procedures. the buoyant density of the mtDNA in neutral CsCI was 1.702 gm/cm3. a value consistent with the melting temperature of the mtDNA. Only linear molecules were observed by electron microscopy. These molecules were homogeneous in size with a monomer molecular weight of 25.6 × 106 daltons. the size of the mtDNA determined after digestion with the restriction endonucleases EcoRI or Hind III agreed with the value obtained by electron microscopy. These studies also revealed that the digestion pattern of mtDNA from stock 172 differed from that of the other 3 stocks (51, 127. 203) examined. Some mtDNA molecules exhibited snapback reassociation following denaturation.

Notizen: RESUME L'étude détaillée du cortex et des organelles buccaux de Cyrtolophosis mucicola montre que ce Cilié possède une organisation structural corticale comparable à celle de Woodruffia, Platyophrya, Kuklikophrya et des Colpoda. Tout en restant conforme au plan général d'organisation de ces derniers, il a des variations spécifiques décelées au niveau des organelles buccaux qui confirment la position de C. mucicola dans la famille des Cyrtolophosididae, incluse dans le sous-ordre des PLATYOPHRYINA.

Notizen: ZUSAMMENFASSUNG Als Kineten werden in dieser Arbeit die intra- und extrazellular in der Hamolymphe sowie im Ovar (ein-schlieBlich der Oocyten und Eier) der Ubertragerzecken auftretenden motilen Entwicklungsstadien (“vermikuli”) der Babesien bezei-chnet. Kineten von Babesia bigemina Smith & Kilborne, in der Hamolymphe von Boophilus microplus Canestrini, wurden ultramor-phologisch und ultra-enzymcytochemisch (saure Phosphatase, saure unspezifische Esterase) untersucht. Kineten von Babesia ovis (Babes) Starcovici in Hamolymphe und Ovar von Rhipicephalus hursa Canestrini & Fanzago wurden im wesentlichen ultracytochem-isch untersucht. Die Pellikula der Kineten von B. bigemina ist komplex und aus 3 Membranen zusammengesetzt (Pellikularkomplex): einer auBeren Membran (dem Plasmalemma) und 2 inneren dicht aufeinander liegenden Membranen. Die auBere Membran ist ˜8 nm dick und offenbar von einer strukturlosen Schicht von ˜3 nm Dicke bedeckt. Jede der beiden inneren Membranen ist ˜6 nm stark. Der Abstand zwischen der inneren Doppelmembran und dem Plasmalemma betragt 7,5 nm. Die Gesamtstarke des Pellikularkomplexes wurde mil 30 nm gemessen. Die beiden Innenmembranen der Pellikula sind wahrscheinlich Abkommlinge des endoplasmatischen Retikulums (ER), und zwar aus folgenden Griinden: (a) sie schliefien eine Lage hydrolase-aktiven Materials ein; (b) in sich intraha-mocytar aus Kinenten transformierenden spharoiden Stadien wird die innere Doppelmembran der Pellikula augenscheinlich durch eine ER-Cisterne ersetzt; (c) die Dicke der Innenmembran entspricht ziemlich genau jener der ER-Membran. In der pellikularen Doppelmembran befinden sich zirkulare Offnungen unterschiedlichen, durchschnittlich 100 nm weiten Durchmessers. Trotz ihrer Ahnlichkeit mil Mikroporen (die fur den Pellikularkomplex der Apikomplexa charakteristisch sind) zeichnen sich diese Differenzierungen durch einen ganz spezifischen Bau aus. Sie werden hier daher Intrapellikularfenster (IPF) oder Pseudomikroporen genannt. Der Rand eines IPF ist eine Kante, die durch die hier ineinander umschlagenden inneren Pellikulamembranen gebildet wird. Dieser Umschlagkante ist cytoplasmatisches, elektronendichtes Material angelagert. Anders als bei einem Mikroporus ist das Plasmalemma jedoch nicht inva-giniert. In Tangentialschnitten erscheint ein IPF als einzelner, dunkler Ring. Manchmal sind den IPF Rhoptrien assoziiert. Eine den IPF ahnliche, jedoch viel weitere intrapellikulare Offnung befindet sich am Apex des Parasiten. Ihr Rand ist mil der inneren Offnung-skante des Apikalringes kongruent. Typische subpellikulare Mikrotubuli wurden nicht beobachtet.Der Apikalkomplex der Kineten von Babesia besteht aus dem Apikalschirm, einem darunter beflndlichen Kranz aus Mikrotubuli, und Rhoptrien. Mikronemen sind ebenfalls zahlreich vorhanden. Der Apikalschirm liegt unmittelbar unter der Pellikula und ist bei Kineten von B. bigemina eine speichenradahnliche Struktur, bestehend aus radiar an einem radnabenahnlichen zentralen Ring (Api-kalring) entspringenden “Rippen”. Es sei betont, daB der Apikalschirm nicht Teil der Pellikula ist und der Apikalring somit nicht identisch ist mil der iiblicherweise als Polring beschriebenen Struktur. Unter jeder “Rippe” des Apikalschirms verlauft ein Mikrotubulus (= subkostaler Mikrotubulus). Bei Kineten von B. ovis sind die “Rippen” viel weniger ausgepragt. In Oocyten und Eiern weisen sie auBerdem einen konisch zugespitzten Apikalschirm auf. Die Rhoptrien der Babesia-Kineten sind spindelformig und im wesentlichen unter dem Apikalschirm lokalisiert. Sie sind in radiaren Reihen arrangiert, wobei jede Reihe einer “Rippe” zugeordnet ist. Ein Conoid wurde nicht gesehen. Hydrolytische Aktivitat in Spuren wurde gelegentlich in Mikronemen beobachtet. Rhoptrien und Apikalschirm waren stets frei von Phosphatase- und Esterase-Aktivitat.Hinsichtlich ihrer fundamentalen morphologischen Organisation und hydrolytischen Aktivitat zeigt die Pellikula der Kineten von Babesia iiberraschende Ubereinstimmung mit dem Pellikularkomplex der Coccidien. Sie unterscheidet sich von diesem durch die IPF und das Fehlen von Mikroporen (sowie typischen subpellikularen Mikrotubuli). In der Komplexitat der Pellikula sowie vor allem in bestimmten Strukturdetails des Apikalkomplexes (Apikalschirm, Fehlen eines Conoids) sind die Babeji'a-Kineten jedoch auch den Hamosporidien bemerkenswert ahnlich.

Notizen: SYNOPSIS. the pattern of RNA synthesis of intracellular Trypanosoma cruzi amastigotes, immediately following infection of Lesch-Nyhan human fibroblasts, was studied by autoradiography. Amastigote RNA synthesis, determined by [3H]guanine incorporation, was not detected until 2 h after infection. At 8 h postinfection more than 90% of intracellular amastigotes were labeled. It was verified that extracellular trypomastigotes also synthesized RNA. Therefore it was concluded that, if RNA is required for trypomastigote-to-amastigote transformation, this nucleic acid is already present in the trypomastigotes before infection of the vertebrate cell. It is probable that the RNA synthesized by amastigotes during the prereplicative lag period (the period between initial infection and the onset of DNA synthesis) is required for intracellular growth and reproduction.

Notizen: SYNOPSIS. Surface proteins of Tetrahymena were identified by lactoperoxidase iodination, and comparisons were made between a number of strains and species within the genus. an adequate procedure for strain comparisons was found to be solubilization of whole cells following iodination, separation of total cell protein using polyacrylamide gel electrophoresis, and identification of surface proteins by autoradiography of dried gels. the results obtained in the present study show the existence of both interspecific and intraspecific variation in surface proteins of Tetrahymena, but the differences tend to be small within species and large between species. the relation of these cell surface fingerprints to the present taxonomic designations within the genus is discussed. Questions are raised about the functional significance of these surface proteins.

Notizen: Examination for coccidia of 20 domestic sheep (Ovis aries) from a farm in Rome Province revealed the following 5 species: Eimeria ahsata Honess, E. intricate Spiegl, E. ovina Levine & Ivens, E. ovinoidalis McDougald, and E. parva Kotlàn, Mócsy & Vajda. of these species, only E. ahsata was not previously reported in Italy. For this reason, a description of this coccidium and a statistical analysis of size differences between E. ahsata and E. ovina are given.

Notizen: The following gregarines are described from mosquitoes in Taiwan: Ascocystis culicis (Ross) from Aedes aegypti (Linnaeus), Ascocystis taiwanensis sp. n. from Aedes albopictus (Skuse), Ascocystis lanyuensis sp. n. from Aedes alcasidi Huang, and Ascocystis armtgerei sp. n. from Armigeres subalbatus (Coquillett). the gamonts of all species are in the lumen of the midgut of the larvae, and the gametocysts and oocysts in the lumen of the Malpighian tubules of the pupae and adults. Ascocystis culicis matured only in Aedes aegypti and Aedes desmotes (Giles); Ascocystis taiwanensis only in Aedes albopictus and Aedes alcasidi; Ascocystis lanyuensis only in Aedes alcasidi; and Ascocystis armigerei only in Armigeres subalbatus and Aedes alcasidi.

Notizen: Spores of Chloromyxum trijugum Kudo from Lepomis macrochirus Rafinesque and Chloromyxum catostomi Kudo from Notropis dorsalis (Agassiz) were obtained from infected gall bladders, glass-bead sonicated, and examined by scanning electron microscopy. Valves of C. trijugum spores each have a thick ridge running parallel to the sutural ridge. Uncapped cnidocyst pores open into the extrasutural ridges. A pyriform structure of unknown function was observed at the posterior surface in some spores. Spore valves of C. catostomi are sculptured with ridged striations running in various parallel and converging patterns over the entire surface. Cnidocyst pores open into ridges adjacent to the sutural plane. Glass bead sonication was found effective in polar filament extrusion. Discharged filaments were twisted along the long axis and partially coated with mucoid globules.

Notizen: A nutrient-agar method without liquid overlay has been developed for cultivation of ciliates. Three species of Tetrahymena-T. pyriformis strain W, T. rostrata strain UNI, and T. vorax strain V2S, representing the 3 main groups of Tetrahymena species, were used; however the method should apply to other ciliates. Growth on the surface of the agar was facilitated by an optimal surface-to-volume ratio yielding a high density of ciliates (5.8 × 105 cells/cm2 for T. pyriformis at 25 C) and short generation times (3 h for T. pyriformis at 30 C). At the highest density achieved, the cells became irregularly hexagonal and formed a monolayer “tissue” on the agar. Ciliates grown on agar were like those in liquid culture, typical oral ciliature, food-vacuole formation, and typical cortical patterns being retained. Advantages of this method include high cell density, easy recovery, and optimal O2 supply. the organisms can also be cultivated on the surface of sterile cellulose-nitrate filters, facilitating in situ fixation and staining as well as transfer into different media by transfer of filters with cells, without prior centrifugation and resuspension.

Notizen: Ergosterol was the only sterol detected in Herpetomonas samuelpessoai grown in a defined, lipid-free medium. When cultivated in a complex medium, this flagellate was found to contain 6 additional sterols. As measured by incorporation of L-[Me-14C]methionine, in the absence of acetate, the sterol synthesis was greater at 28 C than at 37 C; in the presence of acetate, however, this synthesis was greater at 37 C. When [2-14C]acetate was used as the sterol precursor, the synthesis level at 37 C exceeded that at 28 C.

Notizen: SYNOPSIS The time is ripe for protozoan ecologists to begin the general evaluation of the role of food quality in the energy transformations and materials flow in food webs involving protozoa and other small organisms. Current evidence suggests that major pathways of energy flow at any particular time depend upon the matches between prey species and consumers. There are 2 components to food quality related (informational) energy flow: (a) the information present in the molecular constitution of the prey; and (b) the ability of the protozoa to recognize and use it. If the evidence obtained from trophodynamic studies of 2 marine ciliates, Uronema marinum Dujardin and Euplotes vannus Müller indicates a generalized ability of protozoa to regulate catabolic reactions to points which optimize energetic gains from their food, then it may be one of the keys to the evolutionary successes of the group.

Notizen: SYNOPSIS Litters and soils are special interstitial ecosystems containing water in surface films and pore spaces, large amounts of organic matter, and are subject to extreme moisture and temperature fluctuations. “Terrestrial protozoa” are ubiquitous limnetic species tolerant of high CO2 tensions and possessing efficient encystment mechanisms.Protozoa exploit tiny microhabitats unavailable to larger animals (e.g. nematodes). Naked amebae dominate due to their flexible bodies and interface locomotion. Small flagellates may be abundant, especially in litters. Ciliates are less numerous but their species composition indicates the degree of moisture of the habitat, as do the slower-growing testacea which become prominent in regions of slow decomposition (conifer and tundra biomes). Protozoa promote decomposition by enhancing bacterial metabolism, eating excess bacteria, and excreting simple compounds returnable to plants. Large populations, especially amebae, exploit the abundant bacterial flora of plant root zones (rhizosphere). One protozoon, Colpoda cucullus, has successfully invaded the surfaces of vegetation.

Notizen: SYNOPSIS Interacellular membrane potential and spontaneous changes associated with motile responses in the zooid of Vorticella convallaria Linnaeus were recorded by conventional electrophysiological technics. an all-or-none large transient depolarization (large pulse) occurs in association with a spontaneous contraction of the zooid. A small transient potential change (small pulse) was observed in association with periodic contraction of the contractile vacuole.

Notizen: SYNOPSIS Deer mice Peromyscus maniculatus (Wagner) were trapped near Hammett, Idaho, as a possible source of Besnoitia jellisoni Frenkel and species of Sarcocystis to be used for life cycle studies. Forty-nine deer mice were necropsied; 20 (40.8%) were positive for sarcocysts structurally identical with those of Sarcocystis idahoensis sp. N. the source of S. idahoensis used for life cycle studies was a Great Basin gopher snake Pituophis melanoleucus deserticola Stejneger killed near Hammett, Idaho; 20 sporulated sporocysts measured 11.1 × 13.4 (11-12 × 13-14) μm. Structurally identical sporocysts were found in 7 of 14 Pacific gopher snakes P. m. catenifer (Blainville), and in 6 of 10 San Diego gopher snakes, P. m. annectens Baird & Girard. Totals of 148 deer mice and 17 gopher snakes were necropsied in the course of life cycle studies. Development of the first generation meronts took place within the hepatocytes of deer mice 2-10 days post-inoculation (PI) with sporulated sporocysts. Rosette-shaped meronts (6-8 days PI) contained tachyzoites attached by their posterior poles to a residual body. After release from the residual body, tachyzoites were initially retained in a meront wall and later released from the hot cells Within muscle cells a single tachyzoite-shaped structure was found 11 days PI and PAS-negative metrocyte-containing sarcocysts (2nd generation meronts) 13-34 days PI. PAS-positive material was first seen in sarcocysts 34 days II at which time bradyzoite formation became apparent. At 160 days PI, 10 sarcocysts measured 0.4 × 5.8 (0.2-0.9 × 1.8-9.9) μ and appeared to be mature and structurally identical with those from naturally infected deer mice. After ingestion of S. idahoensis-infected deer mice by gopher snakes, bradyzoites developed directly into microgamonts and macrogametes. These stages were first seen 5 days PI. Microgamonts were generally located above and macrogametes below the epithelial host cell nucleus. Seven to 11 days PI microgamonts were seen with mature microgametes, and oocysts which had not yet begun sporogony were found with oocyst walls. Clinical signs of illness were generally not observed in infected gopher snakes; however, one snake developed anorexia and cachexia, and became moribund after repeated ingestion of heavily infected deer mice. Acute hepatitis associated with developing meronts often was noted in deer mice given over 15,000 sporocysts each. Five to 6 days PI anorexia, weakness, ataxia, and dyspnea were observed: these clinical signs increased in severity until 6-8 days PI, when mice became recumbent and died, or were killed while moribund. Hepatosplenomegaly, petechial hemorrhage o the serosal and cut surfaces of the liver, and icterus were common. Diffuse coagulative necrosis with cellular infiltration (primarily neutrophils) was noted on microscopic examination.

Notizen: SYNOPSIS Catalase activity of Paramecium tetraurelia decreased during autogamy and recovered to normal 5 days later. Autogamy also caused changes in the ciliate's sensitivity to natural ionizing radiations—the decrease in cell growth rate previously described in shielded cultures did not occur when autogamous cells were used. Maximum effect of shielding was observed in 11-day-old postautogamous cells. the role of the catalase in the mechanism of natural irradiation effect is discussed.

Notizen: This paper explores the choices and potential biases involved in valuing one type of government expenditure, medical transfers, and in estimating its antipoverty impact. Three methodological approaches–(a measure of) government costs, (a measure of) cash-equivalent values and (a measure of) funds released–are contrasted both in concept and in practice. We assign benefits to individuals after assuming that Medicare and Medicaid provide insurance to all those who are eligible. The resulting estimates for 1968 and 1974 illustrate the efficacy of these medical transfers in reducing the number of persons in poverty. Two recent studies, one by the Congressional Budget Office, and the other by Morton Paglin, further highlight the importance of medical transfers for estimating poverty, despite the fact that we do not wholly agree with the methodologies which they employ. Our results indicate that in the aggregate, while medical care transfers have a substantial impact on poverty, the choice of a specific estimation approach has little effect on poverty estimates. However, for the elderly and possibly also for other groups (e.g. the rural poor), choice of estimation technique is quite crucial for estimating the extent of poverty.

Notizen: In studies of income distribution household income is the common measure of household welfare, although household per capita income is better since it automatically “corrects” for household size. Perhaps the continued use of the former is a consequence of the belief that in practice the two give very similar results. This paper shows that in many cases those results differ substantially. Policy prescription based on household income rather than household per capita income can be very defective. The paper compares results according to the two income concepts for Malaysian data. U.S. data are then used in a comparison over time.The disparity between the two Malaysian distributions is illustrated by their cross tabulation. A quarter of the households in the lowest forty percent of the household income distribution is in the upper three quintiles of household per capita income; and 10 percent of the same lowest forty are in the highest two quintiles of the second distribution. The paper also shows that the distribution of benefits from public education-measured as the public costs of school years—is very inegalitarian if household income is used. The reverse occurs if household per capita income is used. Similar reversals occur in comparisons involving partitions by occupation and sex of head of household. Women-headed households, for example, have sub-mean household incomes but their household income per capita equals the mean. The paper also examines the differences in the age-income profiles of the two distributions. It then considers whether the much discussed secular stagnation in U.S. measures of inequality is changed if household income per capita is used rather than the usual household income measure. Use of the per capita concept results in a slight decrease in U.S. inequality between 1947 and 1972. Appendix 2 explores how long term growth in per capita incomes and the associated changes in the size composition of households may affect measurements of inequality.

Notizen: Provision of “market goods” follows the decision rules of traditional microeconomics; pricing and resource allocation for such goods tend towards Pareto optimality. The provision of “collective goods,” by contrast, depends on political (or quasi-political) collective decision processes; beneficiaries often receive a share of collective goods free of charge or well below average or marginal (private or social) costs. No inherent tendency towards optimality may be presumed and separate analysis of collective goods becomes an essential part of national goals accounting.The national-income-accounts (NIA) distinction between personal consumption expenditures (PCE) and government purchases of goods and services corresponds roughly to a division between market goods bought by the consumer and a major category of “collective goods” (i.e. “public goods” provided by government). However, a significant proportion of PCE represents “collective goods” paid for by government, business, or nonprofit organizations and provided on behalf of the consumer, whereas a part of NIA government purchases represents services paid for by the consumer (i.e. “market goods”).This article develops operationally meaningful distinctions among “market goods,”“collective goods,” and “tied aid” (a mixed category with market-good and collective-good characteristics). These distinctions are determined by the nature of the decision processes–rather than by the characteristics of the beneficiary or the supplier. This classification is related to the national income accounts and major discrepancies are pinpointed. The blurring of the distinction among market goods, collective goods and tied aid is found to be most consequential in the NIA treatment of “education” and “medical care” services. NIA data for these two services are restructured for national goals accounting purposes in order to illustrate both the quantitative importance and the empirical feasibility of classifying benefits by their respective decision processes.

Notizen: Recently there has been discussion concerning the renewal of the volume measurements of public sector services. This renewal has been proposed e.g. in the recent United Nations Draft Manual on Public Sector Statistics. In the present paper we discuss some theoretical and practical problems connected with this renewal. According to some preliminary calculations concerning the Finnish educational sector, the new methodology might lead to a considerable revision of figures of output and labour productivity in the public sector. The revisions are of such a quantity that they might cause significant changes in the measurement of the volume of the total gross domestic product. This is a fact which may still require reflection before the new methodology is generally introduced, even though the revisions as such may be highly desirable from several aspects.

Notizen: Structural relationships estimated from data obtained in a benchmark study of the expenditures and prices of 16 countries are used to develop a table of real gross domestic product and shares of gross domestic product devoted to private and public consumption and investment for each of over 100 countries in the years 1950 and 1960 through 1977. Price level estimates for total product and the three components are also provided.

Notizen: Taxes as well as government expenditures tend to transform income distribution; the higher they are in relation to GDP, the higher their potential influence appears. It is easier to trace the incidence of taxes than that of expenditures and studies of effects of expenditures on income distribution are not frequent. Changes of fiscal legislation and deficiencies in reporting systems and statistics frequently found in developing countries complicate the task still further.An investigation of this type in a developing country has to face a poorly developed data base and take advantage of different and dispersed sources of information.This paper presents the methodology used for estimating the influence of government expenditures a n income distribution in the case of Venezuela. Although the incidence of fiscal activities on income distribution in Venezuela might not necessarily be the same as in other countries, Venezuelan sources of information are not very different from those existing in other countries of similar level of economic and statistical development and procedures used could appropriately be adapted to other countries.

Notizen: The question addressed in this paper is: Why can't we have a good measuring rod of the economic and social performance of our society? The answers are basically positive but lie mostly in the direction of (1) avoiding simplistic solutions such as turning the national income accounts into a measure of social welfare and (2) providing the elements of an information strategy to obtain such a measure or more accurately such a set of measures.The proposed information strategy highlights five activities: (1) the presentation and analysis of welfare outcomes, an activity which is analogous to but broader than “social indicators”; (2) social accounting which includes economic accounting, demographic accounting, and time-use accounting; (3) model building and operation which, unlike accounting, are concerned with behavioral or causal relationships used to explain and project welfare outcomes; (4) hypothesis testing to develop new insights into economic and social behavior; and finally (5) the building and maintenance of a data base required for carrying on the aforementioned four activities.

Notizen: The importance of non-personal shareholders in Malaysian corporations is widely acknowledged. However, up till now, very little has been known about the nature of these shareowners, their manner of equity ownership (especially their size of holdings hence degree of share concentration), their country of incorporation and how they themselves are controlled i.e. whether Malaysian or foreign. This paper attempts to fill this gap with data compiled from official shareholders' lists of the largest ninety-eight Malaysian incorporated companies engaged in manufacturing, for a point in time 1975–75, which is towards the end of the Second Malaysia Plan period. Some of the empirical findings are then compared with those of a few selected countries.