ALBERT

Notes: SYNOPSIS. Tetrahymena pyriformis strain HSM secrete large quantities of lysosomal acid hydrolases into the medium. The finding that 2 isozymes of β-N-acetylhexosaminidase (2-acetamido-2-deoxy-β-D-glucoside acetamidodeoxyglucohydrolase; EC 3.2.1.30) could be resolved by DEAE ion exchange chromatography and of possible differences between the secreted mixture and the intralysosomal hexosaminidase activity suggested that Tetrahymena might prove useful for studies of the control of lysosomal hydrolase isozyme secretion. In the present paper, we report a considerable purification of these isozymes and describe a number of their kinetic properties. Four isozymes were isolated into 2 major forms, A1 and B1, and 2 minor forms, A2 and B2, which were similar to the respective major forms in all kinetic properties tested. Hexosaminidase B1 has a molecular weight of ˜93,000 daltons and is inhibited by high concentrations of p-nitrophenyl-N-acetyl-β-D-glucosaminide. The inhibition is reversed by ethanol. Hexosaminidase A1 has a molecular weight of ˜170,000 and is not inhibited by high concentrations of substrate. The A forms are relatively less active against p-nitrophenyl-N-acetyl-β-D-galactosaminide than the B forms. Neither hexosaminidases A1 or B1 has any endo-β-N-acetylhexosaminidase activity. Comparison of the properties of the 2 major isozymes suggested that measurements of activity obtained under different assay conditions could be used to quantitate the amount of each isozyme in a mixture of the two. Log- and early stationary-phase cells secrete ˜20% of isozyme A and 80% of isozyme B into the medium or into a dilute salt solution. With increasing culture age the fraction of isozyme A secreted rises to over 90%. Supplementation of the proteose-peptone growth medium with glucose causes a decrease in total hexosaminidase subsequently secreted but with no change in proportion of each isozyme. Cells suspended in a dilute salt solution containing 0.1 mM L-propranolol secrete slightly more isozyme A than do control cells suspended without L-propranolol. Phenoxy-benzamine (0.2 mM) causes a slight decrease in the proportion of isozyme A released.

Notes: Living Entamoeba histolytica trophozoites were examined by phase-contrast microscopy. Intact critical point dried trophozoites were examined by transmission electron microscopy at an accelerating voltage of 1000 kV (HVEM) and by scanning electron microscopy (SEM). Half and quarter m̈ thick sections of epoxy-embedded trophozoites were examined by HVEM. Many of the trophozoites of 2 strains examined had surface filopodia, 1 to over 100 pan in length. The cytoplasm of filopodia was continuous with the cytoplasm and bounded by surface plasmalemma bearing a glycocalyx. Structures called “surface-active lysosomes with trigger,”“dendritic plasmalemmal extensions,” and “extra-amebic vesicles” by previous investigators probably represent portions of filopodia demonstrated in the present study. Filopodia appear to be of frequent normal occurrence in E. histolytica and may function in: (a) endocytosis or pinocytosis; (b) exocytosis; (c) attachment to substratum; (d) penetration of tissue; (e) release of cytotoxic substances; or (f) contact cytolysis of host cells.

Notes: Une nouvelle espèce Minchinia cadomensis parasite du Xanthidé A Rhithropanopeus harrisii tridentatus est décrite. La sporulation resemble à celle des espèces de Minchinia déjà décrite mais les spores possèdent des caractères distinctifs—la spore de forme sphérique est de taille plus petite que celle des espèces américaines; l'opercule est dissymétrique et ses lobes (en section) sont en forme de U à branches divergentes.〈section xml:id="abs1-2"〉〈title type="main"〉SYNOPSIS Minchinia cadomensis sp. n. is a common parasite of the Xanthid crab Rhithropanopeus harrisii tridentatus Maitland living in the canal from Caen to the sea (Calvados, France). Its sporulation resembles that of species of Minchinia found in crabs and oysters in the U.S.A., but the spores have some distinctive characters. The spore is smaller than those of the American species and more nearly spherical; the operculum is asymmetrical and its sides (in section) are raised like the letter U with divergent branches.

Notes: The principal characteristics of stomatogenesis during division in Climacostomum virens are: (A) Kinetosomal proliferation on the left side of a variable number of kineties in the ventral somatic cortex forms an oral primordium consisting of several kinetosomal fields, which then fuse to form a single anarchic field. (B) A constant topographical relationship exists between the primordium and a well defined cortical pattern, the zone of discontinuity. (C) The anarchic field primordium divides into 2 unequal parts—to the left, the AZM primordium, and to the right, the paroral primordium, which differentiates into the apical membranelles, the peristomial field, and the buccal tube. (D) Preoral and oblique kineties of the somatic cortex form along the right side of the paroral primordium. (E) Parental oral structures are partially dedifferentiated. Stomatogenesis in C. virens and other heterotrichs is compared.

Notes: The regeneration kinetics of Chlamydomonas reinhardtii mutants TS-6 and TS-79, whose flagella were mechanically amputated, indicated that the flagellar precursor in cytoplasm was used for regeneration when cycloheximide was present. The TS-6 cells rendered nonflagellate by regression at 35 C did not regenerate in the presence of cycloheximide, indicating that the precursor was inactivated by the high temperature. Neither mutant was able to use the absorbed flagellar components for regeneration in the presence of cycloheximide.

Notes: Flagellar activity in the biflagellate chlorophyte Chlamydomonas reinhardtii is selectively inhibited by Ni2+ or by treatment with Ca2+-chelating agents. Inhibitions of swimming speed, geotaxis, phototaxis, and pattern swimming result from qualitative and quantitative losses in the activity of individual flagella and in the coordination of activity beween the 2 flagella of each cell. Addition of Ca2+ (a) prevents inhibition and (b) restores normal flagellar activity in inhibited cells. Mg2+ is partially effective in reversal of inhibition. Other ions do not cause similar inhibition or reversal of nickel inhibition. The characteristics of inhibition and reversal suggest that the prmary target for nickel is a component of the flagellar apparatus, and that this component uses Ca2+ to perform its normal function in the regulation of flagellar activity. A 2nd target for nickel is a Carequiring process specific to phototaxis (and not involved in the photophobic response).

Notes: We have investigated the susceptibility of Trichomonas vaginalis to Mengo virus infection by comparing the outcome of Mengo virus or purified Mengo virus RNA infection in T. vaginalis and in CCL-1 mouse fibroblasts. While the adsorption and entry of Mengo virus into T. vaginalis occurred in the same manner as in fibroblasts, the uncoating was much slower. In addition, Mengo virus infection of T. vaginalis displayed no eclipse nor any subsequent production of infectious virus. Purified RNA failed to initiate productive infection in T. vaginalis, whereas it provoked viral replication in the fibroblast controls. It was shown by assessment of protein synthesis in T. vaginalis and mouse fibroblasts cell-free systems that the protozoan ribosomes were able to translate endogenous mRNA and poly-U, but not viral RNA.

Notes: Plankton samples were collected in the Northwest Atlantic on the Grand Banks of Newfoundland in August 1976 and on Flemish Cap in March 1977. The samples were taken using a Hardy Continuous Plankton Recorder towed at a depth of 9.1 m. On the Grand Banks the following species were found: Ceratium arcticum (Ehrenberg), C. longipes (Ehrenberg), C. lineatum (Ehrenberg), C. macroceros (Ehrenberg), C. fusus (Ehrenberg). C. tripos (Müller) and Ceratium spp. Other microplankton found in the samples included Radiolaria, Globigerina humilis (Brady), and the tintinnid ciliates Tintinnopsis cylindrica (Daday) and Tintinnopsis spp. In the samples from Flemish Cap only a single species of diatom was found in small numbers. The paucity of individuals in these samples is most probably related to the season of the survey, winter. The population density of C. arcticum had a patchiness with a length scale on the order of 104 m. The plankton tow on the Grand Banks was parallel to the north-south axis of the Labrador Current. This patchiness scale on the order of 104 m may reflect a meandering of the Labrador Current.

Notes: DNA-dependent RNA polymerase III was partially purified from trophozoites and immature cysts of the small soil ameba. Acanthamoeba castellanii. In contrast to the active modulation of the variety of transfer RNA species which are transcribed during encystment, no difference was found in the chromatographic or catalytic properties of the enzyme responsible for their transcription.

Notes: Kariologiya i Genetika Prosteyshikh. [Karyology and Genetics of Protozona (in Russian, English summaries).] Divizenie i Povekenie Odnokletotchnikh Zhivotnikh. [Locomotion and Behavior of Protozoa (in Russian).] Voprosi Ekologi i Prosteyshikh. [Problems of Protozoa (sic) Ecology (in Russian, English summaries).]

Notes: Phospholipids from Paramecium tetraurelia strains 51s and d,95 cultures and isolated cilia were characterized. The following classes of phospholipids were identified in whole cell lipids: the 1-alkyl-2–acylglyceryl and the 1,2–diacylglyceryl forms of phosphonylethanolamine, phosphorylethanolamine. and phosphorylcholine; cardiolipin: ceramide aminoethylphosphonate and 5 other sphingolipids: phosphatidylserine; phosphatidylinositol; and lyso derivatives of the major glycerophospholipids. Cilia lipids were rich in ether lipids, phosphonolipids. and sphingolipids. Net lipid biosynthesis did not occur, as determined by the weight of lipids extracted from culture medium compared with the weight of lipids extracted from culture medium and ciliates after 7 days of growth. Total lipids/cell decreased with culture age. changes in the neutral lipid fraction accounting for the major decrease. Phospholipid class distributions changed with culture age—the glyceryl phosphorylethanolamine and choline content of cells decreased, while the glyceryl ohosphonylethanolamine content remained relatively constant: hence, the ratio of phosphonolipids to total phospholipids increased. All fatty acids observed in total lipids from cells and cilia were also present in the glycerophospholipids. Total lipids from cilia contained a greater percent of polyunsaturated fatty acid than those of whole cells. Whole cells and cilia glyceryl phosphonolipids contained up to 93% eicosatetraenoic plus eicosapentaenoic fatty acids. The enrichment of phosphonolipids in cilia accounted for most of the polyunsaturated fatty acid enrichment observed in cilia total lipids. The fatty acid composition of all major whole cell glycerophospholipid classes changed dramatically with culture age, while only small changes occurred in cilia glycerophospholipid fatty acids.

Notes: Synopsis.The DNA of the macro- and the micronucleus of Tetrahymena thermophila has been compared by various biochemical methods. It became evident from their thermal denaturation temperatures and buoyant densities that the 2 DNAs were very similar in overall composition. Small differences were detected when the sequence complexities of these DNAs were compared by DNA renaturation studies. The studies suggested that ˜ 10% of the micronuclear genome was lost or underrepresented in the macronucleus. Comparison of individual gene levels revealed further differences. By using the technic of gene cloning a micronuclear sequence was isolated which hybridized only with micronuclear, but not with macronuclear DNA. These results indicated the occurrence of elimination or underreplication of this sequence in the macronucleus. Gene amplification was also shown to occur. In the micronucleus only a single copy of rDNA was found integrated into the chromosome. During macro-nuclear development, amplification was observed to occur, and the amount of rDNA to increase, until there were ˜ 200 copies per haploid genome in the mature macronucleus. all of them extrachromosomal and palindromic. The 3rd case of alteration involved a simple repeated sequence, (CCCCAA)n, present in the termini of rDNA and also in many other locations of the genome. Restriction endonuclease digestion studies revealed drastic differences in the organization of the repeats between macro-and micronucleus. These differences may be interpreted as the results of chromosome fragmentation which occurs at every cluster of the repeats during macronuclear development. The relationship between this event and gene amplification and elimination is discussed.

Notes: Synopsis.A satisfactory model of the Tetrahymena thermophila macronucleus must explain its genetic behavior in terms of its constituent molecules. Particular genetic phenomena requiring explanation are (a) phenotypic assortment, here interpreted as resulting from allelic disjunction rather than from differential gene expression; (b) unequal allelic input for some loci, interpreted as a consequence of unequal and selective replication of some alleles during early macronuclear development; (c) delayed assortment at some loci, interpreted as an effect of inequality of allelic input combined with a generalized elevation of DNA content during early clonal history; (d) linkage disruption, probably reflecting continuous somatic recombination rather than dissolution of chromosomes into small repliconic units; (e) assortment depression, brought about by the occasional association of homologous replicons (chromosomes) or else by a differential increase in some classes of replicons; (f) ploidy-related developmental differences in macronuclear primordia are interpreted on the basis of quantitative differences in DNA rather than in terms of an early perception of genic imbalance, (g) Ploidy independent macronuclear DNA content is consistent with several models of size regulation.

Notes: Synopsis.A considerable amount of evidence is now available to indicate that the DNA in the ciliates Oxytricha and Stylonychia undergoes fragmentation when the micronucleus forms a macronucleus. Some evidence suggests that fragmentation may also occur in Tetrahymena and possibly in Paramecium. It is shown that some regulatory or nonrandom segregational mechanism must operate during cell divisions to maintain genic balance in Tetrahymena. Both the hypothesis of macronuclear subunits and also a new hypothesis based on replicative control of DNA are capable of explaining the currently know biochemical, cytological, and genetic facts.

Notes: Synopsis.Unequal macronuclear division in Tetrahymena thermophila introduces variance into G1 macronuclei; unless eliminated such variance would result in continuous variation in DNA content. Analysis of G1 and G2 macronuclear variances reveals that the added variance is eliminated by action on the extremes of macronuclear DNA content. In this model (Model II), macronuclei with small amounts of DNA have an additional complete S phase, while those with large amounts of DNA skip S. From available data, chromatin extrusion is shown not to contribute significantly, if at all, to the elimination of variance. Computer simulations utilizing haploid subunits indicate that model II predictions apply reasonably well to experimental data in terms of coefficients of variation, mean DNA content, and frequency of additional and skipped S phases. The simulations reveal also that within certain constraints, particularly the thresholds for additional and skipped S phases, macronuclear assortment is unaffected by Model II regulation. The relationships between Model II and other aspects of the cell cycle are briefly discussed.

Notes: Synopsis.The amitotic division of the macronucleus of Paramecium tetraurelia produces daughter macronuclei which frequently differ in DNA content. In wild-type cells these differences are small, but can be increased substantially by the action of mutant genes. The variance in macronuclear DNA content would increase continuously if there were no mechanism to regulate it. Paramecium has a very effective regulatory mechanism—all cells synthesize similar amounts of macronuclear DNA, regardless of the number of macronuclei or their prereplication DNA content. DNA synthesis is controlled at the level of macronuclear subunits, and the postreplication macronucleus consists of a mosaic of subunits that have undergone different numbers of replication events during the previous cell cycle. It is evident from experimental results that the amount of DNA synthesized can be influenced by the total size or mass of the cell. Experimental modification of the initial DNA content leads to no change in the amount of DNA synthesized, or in the subsequent protein content of the cells, but modification of cell size causes corresponding changes in the amount of DNA synthesized and in the size of the macronucleus. The implications of these observations for cell growth and the cell cycle are discussed.

Notes: Synopsis.A new species of Microsporida was observed in neurons of the marine mollusc Aplysia californica and the ultrastructure of its spores was investigated. The spores were ˜ 1.3 m̈m long and had a thick 3-layered coat. An anchoring disc and polar aperture were present. The polaroplast occupied most of the anterior half of the spore. The vesicular portion included lengths of loosely packed lamellar structures as well as the usual vesicular profiles embedded in fibrillar material; it was entirely surrounded by tightly packed, electron-dense lamellae. The polar tube had 5 or 6 coils. In this stage of the life cycle (mature spores), the parasites did not appear to be disturbing the host cells. The organism was named Microsporidium aplysiae sp. n.

Notes: Synopsis.Oocysts of Eimeria malabaricas sp. n. and Eimeria bandipurensis from the South Indian tree squirrel Funambulus tristriatus collected in Kerala, India, are described. Sporulated oocysts of E. malabaricas were ellipsoid to subspherical measuring 39.8 (35–45) × 32.1 (29–37) m̈m, with a thick (2.5–3.0 m̈m), 2-layered wall. The outer layer was yellow-brown, striated, and rough. There was no micropyle. but a polar granule was present in 34% of oocysts. The sporocysts were ovoid, 16.0 (14.0–18.0) × 11.2 (11.0–12.0) m̈m, with a Stieda body and a granular residuum. Excysted sporozoites were 21.8 (19.0–23.0) × 3.4 (3.0–4.0) m̈m, with a large refractile body.The sporulated oocysts of E. bandipurensis are redescribed.

Notes: Synopsis. Hammondia pardals sp. n. (Eimeriorina: Sarcocystidae) from Panama Canal Zone is described as an obligate heteroxenous coccidian, with felids as the final host and laboratory mice as the experimental intermediate host. Ovoid oocysts. measuring 40.8 (36–46) × 28.5 (25–35) m̈m. are shed unsporulated. Oocysts were infective only for the intermediate host. the laboratory mouse, Mus musculus, and the intracellular cysts were infective only for felids. Attempted passage of tissue cysts from mouse to mouse was unsuccessful.Mice fed 5 × 104 sporulated oocysts were found to harbor small intracellular cysts, 13–16 × 10–15 m̈m, in the mesenteric lymph nodes, lungs, and intestinal submucosa 15 days postinfection. The meronts in these early cysts were stubby and measured 3 × 6 m̈m. The prepatent period in the felids was 5 to 8 days and the patent period 5–13 days. Experimental infections of definitive hosts were successful with 6/6 domestic laboratory-reared kittens, Felis catus; 5/5 ocelots, F. pardalis; and 1/1 jaguarundi, F. yagouaroundi. None of the exposed raccoons, Procyon lotor, shed oocysts.

Notes: Synopsis. Facieplatycauda pratti gen. n., sp. n. and Myxobolus kozloffi sp. n., from the Klamath Lake sucker,Catostomus luxatus (Cope), are described. The new genus is placed in the family Myxobolidae between Henneguya and Myxobolus. The spore valves beyond the sporoplasmic space are broad and long but not attenuated as an inverted triangle as in certain species of Myxobolus with tails, or of Henneguya with sometimes bifurcated tails. An organism resembling Myxobolus insidiosus (Wyatt & Pratt) was found in the muscle of the body of Salmo clarki (Richardson). Differences in spore structure and site of infection suggest this is a subspecies of the previous form which should be designated Myxobolus insidiosus clarki. A previously unreported species of Myxobolus from Cottus aleuticus (Gilbert) is also described.

Notes: Synopsis.The cortical anatomy and morphogenesis of Cladotricha koltzowii Gajewskaja and Cladotricha variabilis Rumen from the Great Salt Lake, Utah, are described. When compared with 2 marine hypotrichs, Uroleptoides kihni Wenzel and Stichotricha secunda Kahl, from the east coast of the United States, their structure and development suggest that Cladotricha may have descended from an intermediate species within the line of evolution of the Spirofilidae from primitive Kahliella-like hypotrichs. It is suggested that the Kahliella-Cladotricha-Uroleptoides series is separated at the familial level from both the tubicolous and planktonic spirofilids. Further, the structural and morphogenetic differences between Cladotricha and the holostichid Uroleptus appear to be at a subordinal level. These findings are significant in revising definitions of the Hypotrichida, its suborders, and the Urostylidae.

Notes: SYNOPSIS.A scanning electron microscope (SEM) study of Hypotrichomonas acosta (Moskowitz), Trichomonas vaginalis Donné. Pentatrichomonas hominis (Davaine), and Tritrichomonas foetus (Riedmüller) provided new information about the structure of the periflagellar canal: emergence of the flagella from the cell body; structure of the undulating membrane; and position, shape, and size of the pelta. Of special interest were the spatial relationships of the attached part of the recurrent flagellum and the accessory filament in Hypotrichomonas and in the members of Trichomonadinae, i.e. Trichomonas and Pentatrichomonas.

Notes: SYNOPSIS.The occurrence of conjugation in the flagellate, Polytomella agilis Aragão, as first reported in 1910, is confirmed. The gametes made contact with each other in a variety of positions. Our observations differ in minor ways from those reported for P. agilis and are in considerable disagreement with others published on sexual reproduction in Polytomella caeca.

Notes: Book reviews in this article:Regan, M. A. & Chapman, D. J. 1978. A Biochemical Phylogeny of the Protists.

Notes: SYNOPSIS.Under the growth conditions employed, the G1 macronucleus of Tetrahymena pyriformis HSM contains 7.4 × 10-12 g DNA, the G2 micronucleus 0.42 × 10-12 g. DNA content from the Tetrahymena thermophila macronucleus did not significantly differ from that of HSM, but the micronucleus contained about twice as much DNA as the micronucleus of the HSM cells. The T. thermophila macronucleus contained on average enough DNA for ˜ 35 haploid micronuclear copies. A new spreading technic allowed separation of macronuclear substructures from cells of late G2 to early G1. Photometric determination of DNA content of 345 individual structures suggested the existence of 5 different-sized macronuclear structures with a DNA content corresponding to 2, 4, 8, and 16 × the basic values. Comparison of the DNA content of these structures with (a) mitotic micronuclear chromosomes and (b) meiotic micronuclear chromosomes of T. thermophila cells suggests that the 5 basic values of macronuclear structures derive from structures of micronuclear chromosomes. The micronuclear chromosomes of T. pyriformis may be oligotenic. It is suggested that these results further our understanding of macronuclear organization.

Notes: Book reviews in this article: Princibal Para-sites of Domestic Animals i n the United States: Biological and Diagnostic Information Ivens, V. R., Mark, D. L. & Levine, N. D. Geografhic Medicine for the Practitioner. Algorithms in the Diagnosis and Management of Exotic Diseases. Warren, K. S. and Mahmoud, A. A. F., eds.

Notes: Resume.Une analyse des séquences morphogénétiques du CiliéTetrahymena paravorax montre que: (A) La durée de la stomatogenèse de bipartition des formes microstomes en croissance exponentielle représente 45% du temps de génération (stade 1—20%; stade 2—3%; stade 3—3%; stade 4—5%; stade 5—5%; stade 6—9%). (B) La division cytoplasmique est inégale (les proters sont plus petits que les opisthes); la différence de taille initiale entre les 2 produits de fission est probablement compensée par une prolongation de la période de croissance chez le proter. (C) Le pourcentage maximum de réorganisation buccale microstome → macrostome pour les populations asynchrones atteint –˜ 70% au bout de 210 mn d'incubation dans la stomatine. (D) L'initiation de la stomatogenèse de remplacement oral est connectée avec la fin d'une période dont la durée minimale est approximativement celle du stade 0 du cycle normal d'interdivision des microstomes; cette initiation est retardée chez les microstomes exposés à la stomatine dès le début du cycle cellulaire. (E) Le primordium buccal de division peut se résorber en présence de stomatine et la stomatogenèse antérieure peut commencer avant que ne soit terminée cette résorption; la résorption n'est plus induite au-delà d'un point du stade 5 qui précède le début de la constriction du corps cellulaire.SYNOPSIS.An analysis of the morphogenetic sequences in the ciliate Tetrahymena paravorax has shown that: (A) The duration of predivision stomatogenesis in exponentially growing microstomes occupies 45% of the generation time (stage 1—20%; stage 2—3%; stage 3—3%; stage 4—5%; stage 5—5%; stage 6—9%). (B) Cytoplasmic division is unequal (the proters are smaller than opisthes); the initial size difference between the 2 fission products is presumably compensated by an increased growth period in the proter. (C) The maximum percentage of microstome-to-macrostome oral reorganization is –˜ 70% in asynchronous populations, 210 min after suspension in stomatin. (D) Initiation of oral replacement stomatogenesis is associated with the end of a period which has a minimum duration nearly equal to that of stage 0 characteristic of the normal inter-division cycle of the microstomes; this initiation is delayed if exposure of microstomes to stomatin is begun at the onset of the cell cycle. (E) The buccal primordium formed in division can be resorbed in presence of stomatin and anterior stomatogenesis can start before the resorption is completed: this resorption is not induced if the cells have progressed beyond a point which precedes the beginning of the cell furrowing (stage 5).

Notes: SYNOPSIS.In Tetrahymena thermophila subline B, a morphogenic alteration of the anterior end of cells of mating types III and VII results from a cellular interaction which precedes and is a prerequisite for pairing. Cell pairing begins 1 h after starved cells of complementary mating type are mixed. The 1 h-long lag period is characterized by an actinomycin D-sensitive inductive interaction in the first 30 min, followed by a maturation period. Tip transformation begins during the maturation period and continues after pairing. Scanning electron microscopy of deciliated cells reveals ridges which form a chevron meeting in a midline seam between the oral apparatus and the anterior tip. During transformation, the seam broadens until the ridged surface is completely smooth. Melding of the ridges also occurs at the tip of the cell resulting in its blunted appearance. Cells of complementary mating types join in the region of this modified surface, which eventually becomes a specialized cell junction perforated by cytoplasmic bridges. Thus, pursuant to an inductive interaction the structure of the tip of cells is modified in anticipation of the pairing event. Rate of cell pairing might be limited by rate of tip transformation.

Notes: Synopsis.Structure, infraciliature, and ecology of 4 fresh-water Tintinnina were investigated. The lorica of Tintinnidium fluviatile is gelatinous, fragile, and contains some agglutinated material mainly of biologic origin. Its infraciliature consists of ˜ 10 kineties. with kinetosomes arranged in pairs. Only one basal body of a pair is ciliated, except for the uppermost 1–4 pairs which have 2 slightly elongated cilia. In Tintinnidium fluviatile. Tintinnidium pusillum, and Tintinnopsis cylindrata there are 2 prominent ventral organelles. The lorica of T. pusillum is gelatinous and coated with much agglutinated material of biologic and nonbiologic origin. Its infraciliature is similar to that of T. fluviatile, but the uppermost pair of kinetosomes has elongated cilia. The firm loricae of T. cylindrata and Codonella cratera are, built mainly of sharp-cornered structures. The infraciliature of T. cylindrata is composed of ˜ 10 kineties with kinetosomes not arranged in pairs. The infraciliature of C. cratera consists of ˜ 32 kineties, in some of which the kinetosomes are paired, e.g. ventral kinety, and in others not paired, e.g. cilia of the very prominent lateral field and of the other somatic kineties. The uppermost kinetosomes of each somatic kinety are paired and have elongated cilia. In addition, there is an unusual ventro-lateral kinety. The oral apparatus consists of adoral membranelles and a paroral membrane. The membranelles that enter the praecral cavity are very elongate, a feature perhaps unique to Polyhymenophora. The fibrillar system consists of a prominent praeoral ring formed by fibrils extending from the adoral membranelles. A finely meshed silverline system extends over the entire cell.A review of the ecology of the fresh-water Tintinnina indicated that water temperature seems to be the most essential ecologic factor.The systematic position of the Tintinnina is discussed in light of their infraciliature. It is concluded that these organisms are most closely related to Oligotrichina, and probably to Heterotrichina.

Notes: Synopsis. Trypanosoma congolense Broden, an intravascular parasite, binds to vessel walls and erythrocytes of infected hosts. In an attempt to characterize T. congolense adhesion to host cells, an in vitro assay was devised. It was shown in the in vitro experiments that T. congolense binds to bovine, sheep, and goat erythrocytes, but not always to erythrocytes of rats, mice, rabbits, horses or humans. Only the anterior part of live trypanosomes adheres to erythrocytes, and the attachment site on the trypanosomes is destroyed by trypsin and chymotrypsin. Trypanosomes did not adhere to bovine erythrocytes that had been incubated with neuraminidase, sodium periodate and poly-L-lysine. The foregoing experiments suggest that the surface of T. congolense contains a protein-associated site which binds to sialic acid of some host cells. This surface site is most likely responsible for attachment to blood vessels in vivo.

Notes: SYNOPSIS.Attempted infection of 2 young lambs with oocysts of Eimeria christenseni from a goat was unsuccessful. Negative results were obtained also when young kids were fed oocysts of Eimeria ninakohlyakimovae from sheep. There was no difficulty in infecting lambs with the sheep coccidium resembling E. ninakohlyakimovae nor goats with the goat coccidium E. christenseni. Oocysts from the goat measured 38.4 × 26.7 m̈m, but were easily distinguished from Eimeria ahsata from the sheep by sporocyst size and shape, and from Eimeria ovina by oocyst size. Eimeria ninakohlyakimovae-like oocysts from sheep averaged 23.0 ×18.2 m̈m and were morphologically indistinguishable from previously reported goat coccidia.Since no cross infections of sheep and goats could be accomplished with oocysts of Eimeria sp. characteristic of one or the other host, I concluded that sheep coccidia previously known as E. ninakohlyakimovae are distinct from morphologically similar goat coccidia and therefore constitute a separate species. Since the name E. ninakohlyakimovae was first used for coccidia from the goat, the sheep coccidium is renamed Eimeria ovinoidalis with oocyst structure and endogenous stages similar to those previously described from the sheep.

Notes: SYNOPSIS.The reproduction of Toxoplasma gondii RH-strain in vertebrate cells was studied in a controlled-environment culture system. The lag period before reproduction and the doubling time of individual parasites were determined using a least-squares linear regression method of analysis which does not artificially constrain the data. In the majority of cases, the time intercept of the linear regression line was either zero, implying the lack of a lag phase before reproduction, or negative, implying the parasite had completed part of its reproductive cycle before entering the host cell. The mean doubling time of T. gondii is 10.9 h in bovine embryo skeletal muscle cells and 8.3 h in HeLa cells. This difference is not significant at the 5% level. The population doubling times of mouse-derived parasites is best described by a gamma distribution.

Notes: Synopsis.Eighteen strains of algae, including 17 formerly symbiotic with Paramecium bursaria, were tested for capacity to release sugar. Detectable amounts of sugar were found in the supernatant fluids from 10 strains, including 6 strains infective for aposymbiotic P. bursaria syngen 2. The other 4 sugar-releasing strains were noninfective and released ˜26–46 m̈g sugar/mg dry cell weight compared to ˜90–175 m̈g sugar/mg dry cell weight for infective strains. This relationship of infectivity with capacity to release sugar supplements data that indicate a relationship of infectivity with resistance to Con A agglutination. The correlation is completed if we assume that resistance to Con A agglutination and capacity for sugar release must both be present in an algal strain for infectivity. The data thus strongly suggest that these 2 characteristics must be present for infectivity by any algal strains for aposymbiotic P. bursaria syngen 2.

Notes: Book reviews in this article: Annual Review of Microbiology. Starr, M. P., Ingraham, J. L. & Raffel, S., eds.

Notes: SYNOPSIS.At room temperature (˜20 C) the concentration of 1 mg/liter of chromium, as CrO 3, and a 3–h exposure were the conditions at which most Euglena gracilis survived. Euglena subjected to 31.5 ± 0.5 C for 1 h, then cooled to room temperature and treated with Cr, was as sensitive to 0.001 mg/liter as to 10 mg liter. When simultaneously subjected to 31.5 ± 0.5 C and Cr, survival of Euglena was 50% at concentrations down to 0.001 mg/liter by the end of 3 h.

Notes: Synopsis.The ability of carotenoids to protect a heterotrophic dinoflagellate, Crypthecodinium cohnii, from photodynamic damage by sunlight in the presence of an exogenous dye was demonstrated. Wild-type C. cohnii and 2 carotcnoid-deficient mutants were plated on agar-solidified media and exposed to natural sunlight. The wild-type strain, which synthesizes γ–carotene and β–carotene, had the lowest mortality. Mutant car 17 which accumulates mainly §–carotene had an intermediate mortality rate while the albino mutant, car 3, which contains only phytoene, lost viability most rapidly. Wild-type cells treated with diphenylaminc, a carotenogenic inhibitor, were killed at the same rate as mutant car 3. The survival rate of mutants on exposure to sunlight was dependent upon the chromophore length of the accumulated carotenoids. The 3 strains showed no difference in rate of mortality when exposed to ultraviolet light. Protection from sunlight by accumulation of carotenes may be an important ecological factor for this species whose natural habitat is tidepools.

Notes: SYNOPSIS.A new design of flow vessel provides a method for continuous culture of P. falciparum in a settled layer of human erythrocytes with a slow flow of culture medium over them. The parasitemia is kept fluctuating from ˜ 1%, just after addition of fresh erythrocytes. to ˜ 10%, 2 or 3 days later. Each vessel provides each week 3 harvests, each containing ˜ 0.6–1 × 109 parasites.

Notes: Synopsis.Gametocytes of Plasmodium falciparum were produced in continuous cultures but eventually declined in numbers after 3–4 months in vitro. Their development progressed in a consistent pattern, from small rounded, through triangular, to ellipsoidal, and finally after 8 days to crescentic forms. Morphologic maturity occurred at 8–9 days, but the gametocytes would not exflagellate in vitro, even after 14–18 days of development. Thus, current culture methods cannot produce a continuous supply of functional gametes for further studies.

Notes: Synopsis.A simplified method for obtaining axenic cultures of Blepharisma involves the use of penicillin, streptomycin, and tetracycline. Cytologic examination disclosed no significant effect of these antibiotics on the structure of the ciliates.

Notes: Synopsis.Crude preparations of kinetoplast vesicles were used to investigate the respiratory chain components in Leishmania tropica promastigotes. In difference spectra from enzymically and chemically reduced preparations, cytochrome b was the predominant component. By utilizing special assays designed to minimize the influence of cytochrome b on difference spectra, cytochromes a, a3, and c333 were demonstrated. Difference spectra from chemically reduced preparations indicated that pyridine nucleotides (NADH) and flavoproteins were also part of the respiratory chain. The presence of these components as well as their response to respiratory inhibitors and ascorbate provide evidence for the presence of a typical trypanosomatid respiratory chain in L. tropica promastigotes.

Notes: SYNOPSIS.The carotenoid compositions of 15 nitrosoguanidine-induced mutants of Crypthecodinium cohnii, a heterotrophic dinoflagellate, were determined by chromatographic and mass spectral analyses. Wild-type C. cohnii grown with irradiation of 250 m̈ W/cm2 visible light at 27 C synthesizes β-carotene (33%) and γ-carotene (67%) amounting to 0.083 mg/g dry wt. There are 4 types of carotenoid-deficient mutants: (I) albinos which synthesize no C40-carotonoids: (II) albinos blocked at the level of phytoene desaturation; (III) cream-colored cells which accumulate mainly §–carotene, with phytoene and/or β-zeacarotene also present; and (IV) light-orange strains which synthesize reduced amounts of β-carotene and γ-carotene.Dark-grown wild-type cells produced 35% as much carotenoids as light-grown cells. Inhibition studies revealed that diphenylamine (3 γ) caused phytoene accumulation; nicotine at 0.9 mM blocked the final cyclization, to cause γ-carotene to accumulate in wild-type cells. Inhibition by adenine and guanine (1.5 mM) of carotenogenesis was demonstrated for the first time in any system. The effect of these purines was similar to that of diphenylamine addition: phytoene desaturation was largely inhibited.The carotenogenic system in this dinoflagellate is similar to that of green algae and higher plants, and is under nuclear genetic control.

Notes: Synopsis. Tetrahymena pyriformis strain HSM secretes large quantities of acid hydrolases into the culture medium. An enzyme secreted by the ciliate and capable of degrading walls of streptococci was identified and purified to a considerable degree. The pH optimum of this enzyme was 3–4, and it was eluted after cytochrome c from Sephadex G-75 columns. Unlike lysozyme, the enzyme was thermolabile at pH 2.9, but relatively thermostable at pH 8.1. It degraded “C-labeled cell walls of streptococci releasing reducing groups. Cell walls prepared from different strains of streptococci differed in susceptibility to this enzyme, the most sensitive strain tested being of group A, type T12. It was shown in immunologic studies that this hydrolase released the group-specific carbohydrate from the walls. Secretions of Tetrahymena from early stationary-phase cultures had more bacterio-lytic activity than those from cells from late stationary-phase cultures. Further, cells from cultures grown in glucose-supplemented medium secreted less of the enzyme than ciliates of comparable age grown in unsupplemented proteose-peptone. The newly isolated bacteriolytic enzyme, presumably of lysosomal origin, may be helpful in characterizing streptococcal cell walls.

Notes: SYNOPSIS.The fatty acids of whole cells and cilia from Paramecium tetraurelia strains 51s and d,95 and from Paramecium octaurelia strain 299s were identified. Ciliates were grown axenically in 3 types of culture media. More than 30 fatty acid species were identified and their structures determined by gas chromatography, mass spectrometry, argentation chromatography, hydro-genation, and fragmentation technics. The major fatty acids were hexadecanoic, octadecanoic, 9-octadecenoic, 9,12-octadecadi-enoic, 6,9,12-octadecatrienoic, and 5,8,11,14-eicosatetraenoic acids. Minor variations in fatty acid compositions were observed in cells grown in the different culture media as well as among the 3 strains. Major changes in fatty acid compositions occurred with culture age and cell density. The cells accumulated exogenous lipids in cytoplasmic vesicles. These lipids were utilized as culture age progressed. Both cellular volume and lipid content were greater in young than in older cultures. Fatty acid compositions of both whole cells and cilia changed with age and had a relative decrease in saturated, short-chained and odd-numbered carbon acids. Cilia lipids were enriched in long-chained, polyunsaturated acids as compared to lipids in whole cell extracts. Eicosatetra-enoic acid (arachidonic acid) increased to the greatest extent with age in both cellular and ciliary lipids, accounting for 20–60% of the total fatty acids in cilia. The age-related change in fatty acid composition in Paramecium is among the largest observed in eukaryotic organisms. It was concluded that some minor fatty acids found in Paramecium lipids were incorporated directly from certain culture media and that Paramecium had w3, 6, and 9 pathways for polyunsaturated fatty acid biosynthesis.

Notes: SYNOPSIS. Isoenzyme electrophoresis of 7 different enzyme systems was used to compare 24 strains of Naegleria fowleri and 6 strains of N. gruberi. The 30 strains could be grouped into 4 distinct categories based upon zymogram patterns. No interstrain band variation in all enzyme systems was demonstrated in pathogenic strains of N. fowleri. Three nonpathogenic high temperature-tolerant strains of Naegleria had similar zymograms. Four of the 5 remaining nonpathogenic Naegleria strains had no interstrain band variation. Based upon zymograms, the 22 pathogenic strains constitute a homogenous species. Similarly the high temperature-tolerant nonpathogenic strains formed a cohesive group. The remaining nonpathogenic strains could be separated into 2 groups.

Notes: SYNOPSIS The DNA content of Euglena gracilis and murine leukemic cell line L-1210 were varied by growth under abnormal conditions. DNA measurements by colorimetry and by flow microfluorometry were compared and absolute calibration of the flow device was established.

Notes: SYNOPSIS Two glutamate dehydrogenases, NADH-linked (EC 1.2.1.2) and NADPH-linked (EC 1.2.1.4.) were isolated from the epimastigote forms of Trypanosoma cruzi and purified. Both enzymes exist as hexamers. The molecular weights of the native NADH-and NADPH-linked glutamate dehydrogenases were estimated to be 360,000 and 265,000, respectively, and those of the subunits to be 58,000 and 43,000, respectively. The isoelectric point of the NADH-linked dehydrogenase is at pH 5.25 and that of the NADPH-linked enzyme at pH 5.1. The activities of both enzymes are regulated by product inhibition. In addition, purine nucleotides were shown to be potent inhibitors of the NADH-linked glutamate dehydrogenase.

Notes: SYNOPSIS The following new taxa of septate gregarines are established: METAMERIDAE fam. nov. includes genera Metamera Duke, Deutomera Bhatia & Setna, and Cognettia gen. n., the last with the type and only species C. legeri (Cognetti de Martiis); family GREGARINIDAE Labbé includes Degiustia gen. n. with the type and only species D. hyallela (Batten & DeGiusti); Cirrigregarina gen. n., with the type species C. spissa (Henry) and another species, C. kamenote (Hoshide); and Molluskocystis gen. n., with the type and only species M. pterotracheae (Stuart). Family HIRMOCYSTIDAE (Grassé) includes Arachnocystis gen. n., with the type species A. arachnoidea (Devdhar & Gourishankar) and 3 other species A. nitida (Geus), A. oribatidae (Geus), A. scutovertexi (Erhardová). Family ACTINOCEPHALIDAE (Léger), subfamily Actinocephalinae (Léger), includes Chilogregarina gen. n., with the type species C. striata (Léger & Duboscq) and 3 other species C. brasiliensis (Pinto), C. dujardini (Schneider), and C. stella (Léger).

Notes: SYNOPSIS The structure and gliding movement of Gregarina garnhami Canning, a eugregarine found in the midgut of the desert locust, Schistocerca gregaria, have been studied by light microscopy and transmission and scanning electron microscopy (EM). Ultrastructural studies revealed that the cytoplasm of G. garnhami is separated from the epicyte folds by a basal lamina. The pellicle consists of 3 membrane layers. At the tips of the epicyte folds there are 2 sets of longitudinally oriented filaments. An ectoplasmic network is present in the ectoplasm and the endoplasm contains numerous paraglycogen granules. The effect of cytochalasin B on G. garnhami was studied. Examination of scanning EM preparations of gliding and stationary gregarines yielded inconclusive results. In some instances the epicyte folds were thrown into waves; in others the folds were straight, regardless of treatment before fixation. Gregarina garnhami glides through its environment without any apparent deformation in shape. As it moves, a mucus trail is left behind it. Phase-contrast observations were made of centrifuged gregarines in which the endoplasm was displaced. Centrifuged gregarines continued to glide. Displacement of the endoplasm allows visualization of the epicyte folds in gliding animals. No lateral waves were seen in the epicyte folds of gliding centrifuged animals.

Notes: RÉSUMÉ L'infraciliature corticale de Kuklikophrya dragescoi gen. n., sp. n., se compose de cinétosomes jumelés. Chaque cinétosome du couple posséde des fibres transverses. Les fibres transverses antérieures sont doublées d'une lame de matériau dense et les transverses postérieures sont dirigées vers la partie postérieure du corps. Le cinétosome postérieur porte seul une courte protubérance en position de cinétodesmale. Le cortex a une couche alvéolaire bien développée, une limite ectoendoplasmique épaisse. Le trait saillant de la ciliature buccale est l'existence d'une circumorale dont l'infraciliature est faite de paires de cinétosomes ciliferes. La polarité antéropostérieure du segment paroral est inversée par rapport à celle du Cilié. Les organelles ciliaires adoraux et préoraux sont constitués de 2 rangées de cinétosomes ciliférs, dont chacun porte des fibres postciliaires. Une armature de némadesmes entoure le cytopharynx; ce dernier est soutenu par des rideaux de microtubules qui lui conferent un aspect feuilleté trés particulier. Le phagoplasme est formé de vésicules de type “vermicelles”. Le micronoyau est inclus dans l'espace périnucléaire du macronoyau.

Notes: SYNOPSIS Naegleria gruberi amebae normally transform into biflagellated cells. When subjected to high temperatures during flagellate differentiation, populations develop an average of 4–5 flagella/flagellate. Attempts to maximize this phenomenon by altering cellular and environmental variables revealed that: (a) few Naegleria isolates become multiflagellated: strain NB-1 gives the greatest response to heat shocks: (b) temperature is the most critical variable: highest numbers of flagella are obtained only if cells are temperature-shocked at precisely 38.2 ± 0.1 C, then returned to 19–22 C to complete differentiation; (c) although pH alone does not affect numbers of flagella. a pH optimum of 5.5–7.0 exists for temperature-shocked cells; and (d) single cells in microdrops become multiflagellated, but the population response is density-dependent. Optimal conditions are described for growing, washing, and transforming amebae to generate reproducibly highest numbers of flagella.

Notes: Wall ultrastructure and sporogenesis were studied in plasmodia of Henneguya adiposa Minchew which infects the channel catfish, Ictalurus punctatus (Rafinesque). Plasmodia were located among connective tissue bands of the adipose fin and were always separated from host fibrocytes by collagen fibers. The plasmodium wall consisted of a single unit membrane which was continuous with numerous pinocytic canals extending into the parasite's ectoplasm. The membrane was highly convoluted, producing an irregular parasite surface, and was covered by a fine granular coat of almost uniform thickness. Early sporogenic stages were located in a zone of cytoplasm rich in mitochondria, just interior to the zone of pinocytic canals. Later sporogenic stages, including mature spores, were concentrated in the center of the plasmodia. Sporogenesis began with the envelopment of one generative cell, the sporont, by a 2nd, nondividing, cell—the enveloping cell. The sporont and its progeny proceeded through a series of divisions until 10 cells were present within the enveloping cell. Once divisions were completed, the 10 cells became arranged into 2 identical spore-producing units, each consisting of one binucleate sporoplasm and 2 capsulogenic cells, all surrounded by 2 valvogenic cells. Later stages of spore development indicated that capsulogenesis, valvogenesis and sporoplasm maturation occurred concomitantly.

Notes: La mise en évidence de chromosomes méiotiques (= complexes synaptonématiques) chez 7 espèces de Microsporidies appartenant à 6 genres différents est le signe de l'existence d'une méiose et par là d'une caryogamie. La méiose chez les espèces qui la présentent, se déroule au début de la sporogonie, au stade du jeune sporonte. De ce fait, la caryogamie doit être localisée entre le stade “spore” et la fin de la mérogonie c'est-à-dire dans la phase du cycle biologique la plus obscure. Les espèces de Microsporidies étudiées. a spores uninucléées et schizogonie à diplocaryon (type Thelohania), montrent que les 2 noyaux accolés, renfermant des chromosomes méictiques, ne fusicnnent jamais, mais au contraire se séparent au début de la sporogonie avant que chacun d'eux ne subisse la méiose. Leur séparation est conduite par un organite dont la structure et le rôle sont mal connus. Toutefois sa structure rappelle celle du centre cinétique, organite auquel il pourrait être assimilé.Les 2 espèces de Nosema observées n'ayant pas révélé de complexes synaptonématiques. leur cycle est difficile à comprendre: ou bien caryogamie et méiose interviennent dans la partie non connue du cycle, ou bien il n'y a pas de phénomènes sexuels du tout. Dans ce cas. le cycle type Nosema correspondrait á une multiplication asexuée qui pourrait trouver son explication dans la théorie du dimorphisme des Microsporidies.Cette étude montre que le cycle biologique des Microsporidies n'est pas un cycle haplobiontique comme on aurait pu le croire par rapprochement avec les Sporozoaires.〈section xml:id="abs1-2"〉〈title type="main"〉SYNOPSISSynaptinemal complexes have been demonstrated in 7 microsporidian species belonging to 6 different genera (Gurleya, Thelohania, Pleistophora. Tuzetia, Baculea, Glugea). Thus, it can be presumed that a meiosis and consequently a karyogamy occur during their life cycle. Meiosis occurs at the beginning of sporogony: therefore, karyogamy must occur between spore and merogony. i.e. during the poorly known part of the life cycle. In the microsporidian species studied, with uninucleate spores and diplokaryotic merogony (Thelohania for instance), the 2 joined nuclei, each of them containing meiotic chromosomes, not only fail to fuse, but actually separate at the beginning of sporogony; afterwards, each of them undergoes melosis. Their separation is accompanied by the appearance of an organelle whose structure and function are poorly understood. However, its structure resembles that of the kinetic center.The Nosema species studied do not have synaptinemal complexes: thus, their life cycle is difficult to understand: either karyogamy and meiosis occur during the unobserved part of the life cycle, or sexual phenomena are absent altogether. In the latter case, the Nosema-type life cycle might be limited to vegetative multiplication which could be explained by the dimorphism theory of Microsporidia.It is shown also in the present study that the life cycle of Microsporidia does not involve haploid organisms which it might be thought to contain by comparing it with the cycles of sporozoa.

Notes: Jahn, Theodore L., Bovee, Eugene C. & Jahn, Frances F. 1979. How to Know the Protozoa.

Notes: Rabbits infected either orally or intratracheally with cell culture-grown Encephalitozoon cuniculi were monitored regularly for serum antibody levels and E. cuniculi in the urine. Their responses were compared with intravenously inoculated and uninoculated control rabbits.All rabbits receiving E. cuniculi developed serum antibodies, generally within 3 weeks, and excreted E. cuniculi by 6 weeks. In the acute stage of infection, the organs most affected were lung, kidney and liver; the brain and gut were unaffected. However, during chronic infection, the brain, kidney, and heart were the only organs found to be involved. Antibody levels were very high at this stage. Thus both the oral and tracheal routes may be normal routes of infection with E. cuniculi in adult rabbits.

Notes: The first successful cryopreservation of Ochromonas danica and Ochromonas malhamensis is reported. The freezing method was consistently reproducible for the former, but not for the latter. Ochromonas danica cultures established from frozen material still could be used as test organisms for assay of thiamin. This is the first report of a protozoon retaining its assay property after being frozen to -196 C.

Notes: Leishmania tropica promastigotes transport L-proline through an active uptake system that has saturation kinetics, temperature dependence, a requirement for metabolic energy and transport against a concentration gradient. In experiments lasting 10 min, less than 10% of the proline transported is incorporated into macromolecules. The remainder is largely unaltered proline with an intracellular concentration nearly 60 times that in the reaction mixture. The uptake system has a relatively broad specificity; it is competitively inhibited by D-proline as well as by alanine, methionine, valine, azetidine-2–carboxylate, thioproline, 3,4–dehydroproline, hydroxyproline and α-aminoisobutyric acid. Pre-established intracellular proline pools exchange with external proline as well as compounds that compete with it for uptake. Evidence is presented that feedback inhibition and transinhibition may regulate proline uptake in this organism.

Notes: Bloodstream forms of Trypanosoma cruzi had a substantial increase in respiration in the presence of acetate. Oxidation of acetate took place via the tricarboxylic acid cycle and involved an antimycin A-sensitive respiratory pathway. Oxygen uptake in the presence of acetate was as sensitive to antimycin A inhibition as was CO2 production. There was a 6–7% residual O2 uptake which was not inhibited by high antimycin concentrations. Human anti-T. cruzi sera had no effect on oxygen uptake.

Notes: Whole cell respiration rates were measured polarographically for Naegleria gruberi during growth in agitated cultures. Log growth phase amebae consumed 80 ng atoms O/min/mg cell protein. At stationary phase, respiration rate decreased 4–fold. Intact mitochondria were isolated from N. gruberi and their oxidative and phosphorylative capacities were studied polarographically. As with the mammalian system, the mitochondria oxidized succinate and NAD-linked substrates, but unlike rat liver mitochondria, those from the protozoan rapidly oxidized citrate and NADH. The rates of substrate oxidation were ADP-dependent, with ADP:O ratios equalling ˜ 2.8 for NAD-linked substrates and ˜ 2.2 for succinate. The respiratory control ratios. 2 to 4 for 11 substrates, were dependent on Pi, Mg2+, and serum albumin. Potassium cyanide, azide, malonale, and rotenone inhibited electron transport the same way as that of the mammalian system: however, amytal inhibited both glutamate and succinate respiration. Pentachlorophenol, DNP, and bilirubin uncoupled oxidation from phosphorylation. Difference spectra of oxidized and dithionite-reduced mitochondria had distinct absorption bands of flavins and of c-, b-, and α-type cytochromes.

Notes: This paper explores the imputed service price approach to the pricing of the services of consumer-owned-and-used durables in the construction of the consumer price index, using the services of owner-occupied housing as an illustration. A theoretical framework for analyzing this question is first developed. Certain practical problems are then discussed. The conceptual difficulty of constructing an appropriate rate of return on the basis of available data on interest rates and house prices, in the context of inflation, is explored. Two arguments are advanced that statistical agencies ought not to follow the imputed service price approach in pricing the services of owner-occupied dwellings and other consumer durables. On the one hand, nominal interest rates will, in any short period, reflect monetary policy and not any change in the money “rental” of owner-occupied houses. Second, movements in nominal interest rates will also reflect changes in the money price of pure consumption goods, as well as changes in the money price of houses. The argument is extended to other consumer durables and, in the limiting case, to monetary balances, and it is concluded that in all but trivial cases the application of the service price approach leads to price movements of little or no meaning.

Notes: This paper uses a variety of assumptions to produce calculations of worldwide income distributions from recent international data compilations. The variable quality of the source materials in these compilations along with the arbitrariness in the assumptions required are emphasized. A number of working hypotheses for the worldwide income distribution are offered until data and methods improve. It is suggested the top 1 percent of world population may receive 10–15 percent of world income, the top 10 percent from 45–65 percent, and the bottom 20 percent from 1–4 percent. These figures seem more unequal than those for domestic distributions even for more inegalitarian countries.

Notes: The persistence of poverty and income inequality in less developed countries (LDCs) is a source of serious concern to development economists. To understand the structure of inequality, several researchers using a variety of methodologies have measured the importance of various contributory factors to overall income variability. The available literature—which now includes studies of Brazil, Mexico, Iran, the Philippines, Taiwan, Thailand, Pakistan, and Colombia-has been reviewed elsewhere (Fields, forthcoming). This paper presents additional evidence for urban Colombia, in the process raising some important methodological issues which bear on the design of future research studies.The data set used in this paper is described in Section I. The decomposition of Colombian inequality by functional income source is presented in Section 11 for micro data. Section I11 examines the robustness of source decomposition procedures to data aggregation. Section IV presents inequality decompositions by city, and Section V by other income-determining characteristics. Conclusions appear in Section VI.

Notes: Using a simple simulation model, this paper assesses the impact of relative movements in asset prices on the distribution of wealth during the 1969–75 period. Because of the strong negative correlation between wealth level and the ratio of debt to wealth, this particular inflation induced a substantial drop in the overall level of wealth inequality. Moreover, comparing the portfolios of different demographic groups, we found that middle-aged households gained relatively to younger and older ones, married couples gained relatively to singles, whites gained relatively to non-whites, and home-owners gained relatively to renters. The biggest gainers from this inflation were home-owners with large mortgages and the biggest losers the large stock holders.

Notes: Responding to a perceived growing interest in human wealth estimates, this paper offers a framework for measuring the aggregate stock of human capital and then implements the procedure for the United States male population age 14 to 75. Unlike previous estimates of human wealth that are based upon historical or resource costs, these estimates measure the capital stock as the discounted resent-value of expected lifetime returns. In the estimation, returns are equated with earnings data from the 1970 U.S. Census 15 percent Public Use Sample for out-of-school males, adjusted for employment and survival probabilities, adjusted for an assumed exogenous growth in future earnings, and discounted at 7.5 percent.We provide cross-sectional estimates of individual stocks of human capital by age and educational attainment, as well as expected lifetime wealth profiles for individuals by level of education. These individual profiles can be used to obtain direct estimates of age-specific depreciation which suggest human capital is subject to significant and prolonged appreciation before nearly straight-line depreciation begins around middle age. This finding is all the more significant since resource-cost estimates of human capital which must assume a depreciation pattern to obtain stocks have always imposed a much faster rate much sooner.Finally, an aggregate estimate of the stock of human capital for all males is supplied and its sensitivity to the choice of the discount rate, tax laws, and expected exogenous growth is analyzed. This seemingly-conservative stock estimate is then compared to a much lower resource-cost estimate offered recently by John Kendrick. A discount rate over 20 percent would be needed to equate the two measures. In trying to reconcile the two figures, we raise some new questions about the validity of both approaches for human capital accounting.

Notes: This study is concerned with an effort to analyze changes in costs and prices in the Australian economy by tracing the effects of changes in wages and import prices through the stages of production, using a disaggregated input-output model with lags. The object of constructing the model was to improve, by introducing lags, the accuracy of predictions of the effect of cost changes on prices, and to show the lag structures. Data problems encountered are discussed, and the need for integration of price statistics to enhance their usefulness for analyses such as this is emphasized. Concepts and sources of data are discussed in some detail in an appendix.

Notes: For some considerable time the interest in price statistics has mainly been focused on their use as “intermediate goods”. The requirements of a system of price index numbers which have to be established in this connection are largely in the field of statistical coordination (integration of statistics on quantities, values and prices).Recently the inflation problem has given rise to an increased interest in price statistics as “final goods”. A meaningful analysis of inflation will devote attention to the relation between input prices and output prices. In this article several versions of an analysis of prices of final demand categories based on an ordinary Leontief input-output scheme are presented and the needs for price statistics are discussed. In fact a self-contained system of price statistics emerges from the price analysis.There is a difference in the nature of the price index numbers required in compiling input-output tables in constant prices (Paasche) and that in the case of price analysis (Laspeyres). However the need for price observation runs largely parallel because in both cases the same detailed information on price developments will probably be used.Price analysis gives the possibility of a step-by-step approach in building up a system of price index numbers.

Notes: This paper focuses on a neglected aspect of the treatment of the income unit in the construction of size distributions of income. If the size distribution is to be an indicator of the distribution of economic welfare, and if the economic welfare of each individual in society is to count equally, then conventional distributions are inconsistent with individualistic welfare functions. We estimate size distributions with each person's welfare weighted equally, and contrast these results with those weighting each household unit's welfare equally. The choice of weights is shown to affect both the level and the trend in income inequality.

Notes: After defining economic activity the author lists the chief types of non–market economic activities for which he has prepared estimates for the United States 1929–1973, and briefly describes his methodology and data sources. Some major findings are:(1) As of 1973 GNP adjusted to include the additional imputations was 63.5 percent larger than the official estimate.(2) At least since 1929 imputed values have grown faster than official GNP, especially when both are measured in terms of real factor costs.(3) The personal sector comprises a far larger portion of the national economy-almost one-third—when account is taken of imputed labor and property compensation, and its relative importance has grown.(4) Gross government product is more than 60 percent higher when the imputed rental value of public property is added to the compensation of general government employees.(5) Reflecting the relative growth of non-business wealth, imputed property income has risen much faster than monetized property income. This has mitigated the decline in the property share of expanded gross national income compared with its share in the official estimates.

Notes: This paper investigates the properties of various measures of poverty and of the “difficulty of alleviation of poverty”. It is found that the ranking properties of both kinds of indices can be quite counter-intuitive and that they could be misleading if used for policy evaluation. An alternative index is proposed; it is compared to the other indices and seems to fare rather well. To illustrate, a special reference is made to S. Anand's recent article on poverty in Malaysia.

Notes: This paper is concerned with measurement of the size distribution of personal wealth in Canada. The only available estimates of this distribution are those provided on the occasions when Statistics Canada's Survey of Consumer Finance has surveyed assets and debts. Results of the latest “SCF” to do this, that of 1977, are not yet available. The paper shows that the previous study, conducted in 1970, indicated wealth-inequality as viewed by top quantile shares roughly of the same order as estimated by others for the U.S. and U.K. A comparison of asset and debt aggregates implied by the survey, however, with independent totals indicates that for almost all items the SCF likely under-estimated true holdings. The possible relative importance of sampling and non-sampling errors in explaining this distortion is considered, drawing on Monte Carlo evidence and American validation studies of survey response. It is concluded that sampling error is unlikely to provide the explanation for SCF discrepancies in aggregates, but that non-sampling error is capable of doing so. Finally the 1970 SCF distribution of wealth is re-estimated. First a correction is made for hypothetical differential response according to true net worth. Second an attempt is made to remove the effects of under-reporting by respondents. The “best-guess” re-estimated distribution exhibits mean net worth considerably greater than shown by the SCF but only a slightly greater degree of concentration. Under certain fundamental assumptions this result is surprisingly robust. The appropriate conclusion is not that survey estimates of the distribution of wealth are reliable, but that the strong non-sampling errors affecting the 1970 Canadian SCF wealth estimates may have been composed of almost completely offsetting sources of bias.

Notes: Potential gross national product (GNP) is a measure of the aggregate supply capability of an economy, or the amount of output that could be expected at full employment. Such a measure of output at constant rates of labor and capital utilization is useful as a benchmark for economic performance, calculation of the full employment surplus as an indicator of fiscal policy, and in the projection of unemployment rates. Potential GNP for the United States is estimated for the years 1948–77, and projected for 1978–80. The calculations use a variable benchmark for the full-employment unemployment rate, based on the changing age-sex composition of the labor force, and a constant benchmark for the utilization of fixed capital. A framework for separation of productivity into trend, cycle, and irregular components is developed, and then estimated for the 1948–77 period, using quarterly data. The relationships between various age- and sex-specific unemployment rates are also estimated in construction of the variable unemployment benchmark.

Notes: A review of the United Nations System of National Accounts and its implementation by countries is presently being conducted at the United Nations Statistical Office. This article presents a personal and selective account by the author of the results of that review and its consequences for the present structure of the SNA.Information is included on the level of response by countries for the tables of the SNA national accounts questionnaire. It shows that this response is at present sparce, except for the tables on GDP by end use, cost structure and kind of economic activity.On the more detailed level the feasibility of introducing integrated sector accounts into the system has been examined and different approaches compared. Country practices suggest that one way of facilitating the introduction of such accounts would be to eliminate one essential feature of the dual classification of the SNA, i.e., the distinction between quasi-corporate and other unincorporated enterprises. Other modifications of the SNA structure implied below are the introduction on a limited scale of articulation of transactions, the inclusion of additional aggregate income and balancing items, a reallocation of data between the main accounts and the supporting tables, and a better integration of the SNA matrix with the accounts and tables of the system. A reduction of the present number of independent classifications in the SNA is suggested, based on links between categories of different classifications that are assumed in country responses to the questionnaire. A suggestion is made for a uniform valuation of goods and services and income flows, to replace the present complex valuation guidelines on approximate basic and factor values and producers’ prices.

Notes: The estimation of true basic prices in a Social Accounting Matrix (SAM) has long been recognized as necessary in order to achieve uniform valuation of inputs for meaningful manipulation of the input-output table contained in a SAM, in order to assess the real effects of changes in demand, etc. In practice, approximate basic prices only have normally been calculated in order to avoid matrix inversion among other things. It is equally the case that true basic prices are required if one wishes to assess the price-raising effects of commodity taxes. It is shown through an example that approximate basic prices, as conventionally calculated, are inadequate and potentially misleading for this as indeed they are for achieving uniformity of valuation. There are also problems with the present procedure for calculating true basic prices.An alternative method of calculating true basic prices is given, which has various advantages over the existing method, and a new approximate method is also derived which appears to represent a definite improvement on the present method. For the main purpose of the paper, however, the prices of concern are those charged by producers to which the methodology equally applies.

Notes: Empirical work on the division of real output and prices into tradable and nontradable components has not kept pace with theoretical developments. The conventional proxies of prices and productivity by tradable and nontradable sector are examined and found deficient in several important respects. It is demonstrated that an approach that relies on the long–standing data on gross domestic product by industry of origin can overcome some of these deficiencies. These data are used to construct new annual measures of prices and productivity for tradable and nontradable output for 12 industrial countries over the period 1950–73. While far from precise, the new measures are consistent with the following criteria for distinguishing between tradables and nontradables: the degree of foreign trade participation should be higher for tradables than for nontradables; the degree of international commodity arbitrage, as measured by cross-country correlations of price changes, should be higher for tradables than nontradables; and tradables should be closer substitutes than nontradables for traded goods from other countries (imports).Despite the considerable conceptual advantages of the new measures of prices and productivity over the conventional proxies, correlation analysis indicates that the new and old measures usually move together rather closely in our 12 subject countries. The correlations are higher across the alternative relative productivity measures than for the alternative relative price measures.

Notes: The analysis of the redistribution processes via taxation, transfers and collective services raises several methodological problems among which tax incidence is not the least important. Through two hypotheses of incidence of employers’ social contribution the results of the redistribution of public funds lead to four types of conclusions. Despite the fact that about one third of the French national income is involved in the processes there is no clearcut evidence of any redistribution, except for the nonactive population in so far pensions are considered as redistributed. The positive effects which certain mechanisms may have (e.g. income tax…) are to a certain extent offset, or neutralized, by the anti-redistributive effects of indirect taxation and social contributions. It appears that the results of the redistribution not only depend on the institution network, on the evolution of demographic structures and the rate of growth for the various types of income but also on lack of adaptation between the evolution of the three groups of factors. In last analysis, the reason why redistribution does not appear to have more far-reaching consequences is that social policy amalgamates mechanisms often set up in isolation, whereas any reduction in inequalities must be based on a conscious awareness of the inter-dependence of the situations which create and foster these same inequalities.

Notes: This paper explores the sensitivity of the size distribution of family income in Canada to alternative definitions of income. These alternative definitions examine both wealth generally in the form of an annuity equivalent, and home ownership in the form of imputed rent. An adjustment for family size differences is also made. The impact of these adjustments is assessed for average incomes, inequality, and the incidence of low income for different age groups. The adjustments do have significant effects that vary by age; in particular, the economic position of the elderly seems understated by the usual data. Also, methodological considerations, such as the direct use of micro data and the choice of inequality indicator are shown to be significant.

Notes: Do-it-yourself activities are, by definition, those for which a choice must exist between doing it oneself or hiring someone else. This means they typically involve the own account production of services, but whereas it is customary to include most goods produced on own account in GDP services are conventionally excluded. In principle, however, it is possible to envisage a comprehensive and unique measure of the total final output of all the goods and services produced within an economy whether for sale or own use. Such a measure would be better than GDP as an indicator of long term changes in economic welfare, being independent of any shifts in the ratio of market to non-market production. Moreover, it would be a homogeneous measure with clearly defined limits in contrast to improvised indices of welfare which mix economic and non-economic variables in arbitrary and subjective ways. However, the need for a measure of market output, or something very close to it such as GDP, is still as strong as ever as soon as attention is switched from measurement of long term growth to problems associated with market disequilibria, such as unemployment and inflation.

Notes: Redistributional effects of income transfers, taxation and social goods in Finland have been studied making use of household surveys for 1966 and 1971 and the input-output study for 1970. According to the study the selection of income to be used as the criterion in carrying out the decile grouping substantially influences the picture that is obtained of the magnitude of redistribution. If factor income is used as the criterion in carrying out the decile grouping, the redistribution appears substantially greater than when disposable income is used as the criterion. On the other hand, whether income is calculated per capita or per household does not substantially influence the overall picture of redistribution obtained. The breakdown of factor income seems to have remained practically the same in Finland in the interval between the study years, while redistribution seems to have levelled income differences more in 1971 than in 1966.

Notes: This study attempts to examine the inter-occupational differences in the patterns of cash and in-kind expenditure in rural India on the basis of a special tabulation of The National Sample Survey (NSS), 18th round (February 1963-January 1964) consumer expenditure data. The occupational groups considered here are (i) cultivators, (ii) agricultural labourers, (iii) other agriculture, and (iv) non-agricultural occupations.The analysis is carried out primarily in terms of curves relating item-specific cash/kind expenditure to total cash/total kind expenditure for fifteen selected item-groups of expenditure. For each item-occupation combination, four two-parameter forms of Engel curve together with the log-log-inverse form are estimated and the comparisons across occupation groups are made separately on the basis of each of the two-parameter curve forms which were found to give the best fit for at least one occupation group as well as the log-log-inverse form, using analysis of covariance technique.The results indicate that so far as the cash components of item expenditures are concerned, the pattern of expenditure is considerably influenced by occupational factors. It is observed that cultivators have a cash expenditure pattern different from those of agrictural labourers and of households with non-agricultural activities. The comparison of the kind expenditure patterns does not, however, reflect any clear picture primarily because in most cases the itemwise kind expenditure functions could not be estimated satisfactorily. This analysis also suggests that the specification of itemwise cash and kind expenditure functions employed here may not be the most satisfactory ones in an economy with a high degree of non-monetization and therefore alternative specifications need be examined.

Notes: This paper analyzes the effects of inflation on the size distribution of income, making use of a microsimulation model. It goes beyond earlier analyses not only in the use of microdata but also in the types of inflation modeled. Two different income concepts are used, one the money income concept of the U.S. Census Bureau and the second, called Accrued Comprehensive Income, based on the concept of income as consumption plus the change in net worth. The results of the simulation inflations are presented graphically, as the ratio of real income with inflation to real income without, by income class. The analysis concludes that the income concept chosen is crucially important. While low income households suffer modest losses and middle income households are largely unaffected, whatever income concept is used, the effects on upper income households are extremely sensitive. With a simple money income concept, the well-to-do appear to benefit from inflation but a broader concept reverses this effect. A policy to negate the distributional effect of inflation would benefit primarily the upper income households. Similarly, macroeconomic policies designed to reduce inflation at the price of slower growth and greater unemployment would not aid lower income groups to a significant degree.

Notes: The period 1968–69 to 1973–74 saw a redistribution of incomes in Australia. This is evidenced first by declining differentials between dissimilar persons and secondly by changes in two measures of income inequality, the Gini and Theil coefficients.The inequality coefficients are decomposed into components which distinguish between that part of total inequality due to income differences between dissimilar persons and that part due to inequality between similar persons. It is found that the reduction in inequality was due to the reduction in differentials between dissimilar persons and that inequality between similar persons probably did not change over the period.

Notes: Specific electrical resistivity of natural waters contains information on their genesis. The authors propose to conduct mass and regime observations of this parameter in river and stream beds.The electrical resistivities in streams flowing from under a glacier reveal details formed at the same time as the glacier. Observations in the beds of big rivers show a gradual increase in water salinity overlain by reductions by inflowing glacial waters.The diurnal and annual trend of changes in the electrical conductivity of water associated with the change in the balance of glacial and ground waters has been established near to glaciers.Resistivity observations help to locate discharge sites of sub-permafrost waters, for water.

Notes: The VLF response of laterally inhomogeneous and anisotropic models is calculated numerically using the finite element method.Some results are presented for a slab model in terms both of the polarization parameters, i.e., the tilt angle and ellipticity of the magnetic polarization ellipse, and the amplitude ratio |Hz/Hx|.On the basis of both the ellipticity and the tilt angle, it is possible to discriminate between a poor conductor and a good one. The direction of the dip can be determined from the anomaly profiles of all diagnostic parameters. The effect of the conductive overburden is most noticeable on the ellipticity profile: one observes attenuation for a poor conductor and “negative attenuation” for a good conductor. The anomaly profiles for anisotropic cases are consistent with the ones of the isotropic cases.