bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Cell Surface of Trypanosoma musculi Bloodstream Forms. I. Fine Structure and Cytochemistry*†
Authors: DWYER DENNIS M. , D'ALESANDRO PHILIP A. 
Published: May 2007

SYNOPSIS. An extracellular surface coat was observed at the fine‐structural level on the outer lamina of the pellicular and flagellar membranes of intact Trypanosoma musculi bloodstream forms. The surface coat had a mean width of 9.2 nm, and was composed of a somewhat electron dense, uneven, fibrillar‐like matrix. Brief trypsin treatment of living blood forms completely removed the cell surface coat.Several cytochemical methods applicable to electron microscopy were used to detect the presence and distribution of carbohydrates in the trypanosome's surface coat and pellicular membrane. The polycationic dye compounds employed were: ruthenium red, ruthenium violet, Alcian blue chloride, and lanthanum nitrate. Electron‐dense stain reaction products, indicative of polysaccharides, were evident in the surface coat of cells treated with these dyes, which also agglutinated both living and glutaraldehyde fixed cells. Like the surface coat, the pellicular membrane of trypsinized cells gave strong positive staining reactions with the several dyes, indicating the presence of membrane bounded carbohydrates, and living and glutaraldehyde‐fixed trypsinized cells were agglutinated with the polycationic stains. Bloodstream forms were treated with the enzymes, α‐amylase, dextranase, and neuraminidase. No obvious morphologic difference, however, was apparent between the surface coat of untreated cells and those subjected to treatment with any of the various glycoside hydrolase enzymes. Further, these enzymes had no apparent gross effect on the staining affinity of the surface coat for the several polycationic dyes. Cationized ferritin was used to visualize the negative cell surface charge of T. musculi bloodstream forms. Large quantities of cationized ferritin were bound in the surface coat matrix. Glycoside hydrolase enzyme treatments had no apparent effect on the amount of ferritin bound in the surface coat. Cationized ferritin was bound also to the outer lamina of the pellicular membrane in trypsinized cells, which had quantitatively less ferritin bound per surface unit area than bloodstream forms untreated by the enzyme. Living and glutaraldehyde‐fixed cells were agglutinated with cationized ferritin. The results obtained in the various experiments indicated that polyanionic polysaccharides were constituent terminal ligands of the surface coat matrix and pellicular membrane in T. musculi bloodstream forms.
Allogromia laticollaris: A Foraminiferan with an Unusual Apogamic Metagenic Life Cycle*
Authors: Mc ENERY MARIE E. , LEE JOHN J. 
Published: May 2007

SYNOPSIS. The life cycles of 3 strains of Allogromia laticollaris, a monothalamous foraminiferan, have been studied. Each of the strains had a different, nonclassical, and basically apogamic, life cycle. The Cold Spring Harbor (CSH) strain regularly alternated between 2 agamontic forms: agamont I (uninucleate and diploid) and agamont II (multinucleate and diploid). The complete life cycle took 26 days. Sexual reproduction was rare (0.01%) and autogamous. Small numbers of organisms also underwent budding, binary fission, and cytotomy. The life cycles of the Towd Point (TPA) and Sippewissett (SIP) strains were comparatively abbreviated. Agamont II dominated their typical life cycles, which were completed in 16‐18 days. The life cycle of SIP was basically a continuous cycling of the agamont II phase. Approximately 75% of the schizozoites of the TPA strain developed into agamont II. The other 25% alternated between agamont II and agamont I phase.In the CSH strain schizozoites with ∼ 8 (range 5‐15) nuclei characterized newly formed agamonts II. More nuclei (∼ 25) were found in the other 2 strains. The nuclei in young agamonts II underwent rapid morphologic changes leading to a “mushroom‐like” chromosome appearance and extensive RNA synthesis. Nucleolar material accumulated at the nuclear periphery and eventually was discharged to the cytoplasm. Karyokinesis took place without the breakdown of the nuclear membrane.The single nucleus of young agamont I forms was proportionally quite large. The S1 phase occurred quite early (2‐5 days) in this part of the life cycle. RNA in the CSH strain formed a compact, subcortical, coarsely granular ring, while in the TPA it was cortical and differentiated into finely granular matrix with randomly distributed coarse granules. During the G2 phase the nucleus became further enlarged and eventually amoeba‐form. Intermediate stages in nuclear breakdown were not found.
Efficacy of Antibiotics A204 Sodium, A28695A, and A204np against Coccidia of Rabbits
Authors: FITZGERALD PAUL R. 
Published: May 2007

SYNOPSIS. Three polycyclic, polyether, monocarboxylic acid antibiotics produced by and extracted from a strain of Streptomyces albus and designated A204 sodium, A28695A, or A204np, were specifically tested for activity against hepatic and incidentally against intestinal coccidia of rabbits. All were effective in preventing infections and acceptable to young rabbits when prepared in pelleted feed. Weight gain, however, was not as good in inoculated, medicated rabbits as in noninoculated, nonmedicated controls.No gross pathologic changes were detected except in the livers of inoculated, nonmedicated controls which were severely infected and greatly enlarged. Livers of medicated rabbits were uninfected and normal in appearance and size.
Effect of 4‐Pentenoic Acid on Intermediate Metabolism of Tetrahymena*
Authors: LIANG TONY , RAUGI GREGORY J. , BLUM J. J. 
Published: May 2007

SYNOPSIS. The growth of Tetrahymena pyriformis strain HSM was strongly inhibited by 4‐pentenoic acid. Supplementing the medium with acetate reversed the growth inhibition, but pyruvate was ineffective. Glycogen content was much lower in cells grown with 4‐pentenoic acid than in controls; this effect was not reversed by acetate or by pyruvate. There was little effect of 4‐pentenoic acid on the incorporation of label from [1‐14C]acetate, [2‐14C]glycerol, [1‐34]ribose, [U‐14C]fructose, or [1‐14C]glucose into CO2, but incorporation of label into glycogen was inhibited, the strongest inhibition being on acetate and the weakest (∼ 20%) on ribose, fructose, and glucose. A 3‐compartment model for quantitation of labeled acetyl CoA fluxes was shown to be applicable to Tetrahymena grown in the presence of 4‐pentenoic acid, and experiments were performed to establish the flux of [1‐14C]acetyl CoA into glycogen, lipids, CO2, glutamate, and alanine. It was evident from the results of these experiments that 4‐pentenoic acid did not appreciably inhibit β‐oxidation or lipogenesis, but markedly decreased the glyconeogenic flux of labeled acetyl‐CoA from the peroxismal and outer mitochondrial compartments.At least 2 mechanisms have been proposed for the action of 4‐pentenoic acid: (a) reduction of the levels of acetyl CoA or free CoA and (b) direct inhibition of enzymes by 4‐pentenoyl CoA or its metabolites. Although 4‐pentenoic acid has little effect on acetyl‐CoA metabolism in the inner mitochondrial compartment, the present data suggest that the flux through the outer mitochondrial compartment of acetyl‐CoA derived from pyruvate is inhibited largely by the first, and that the glyconeogenic flux of acetyl‐CoA is inhibited largely by the 2nd mechanism.
Timing and Regulation of Nuclear and Cortical Events in the Cell Cycle of Tetrahymena pyriformis*
Authors: SUHR‐JESSEN PETER B. , STEWART JOHN M. , RASMUSSEN LEIF 
Published: May 2007

SYNOPSIS. Using continuous flow cultures based on the chemostat principle, we varied the cell generation times of the ciliate Tetrahymena pyriformis strain GL, from 4.9 to 22.2 hr and studied various parameters of the cell cycle at 28 C. These included: the duration of the periods required for oral morphogenesis, macronuclear division, cell division, G1 S, and G2. The size of individual cells was also measured.Independent of the growth rate, the period of oral morphogenesis occurred during the last 90 min of the cell cycle. In all cases macronuclear and cell divisions took place during the last part of these 90 min, and the final macronuclear separation occurred just before final cell separation. The S‐period increased slightly, while the G1 and G2 both increased in roughly the same relative proportion to the increasing generation times. Slowly growing cells (generation time 20.5 hr) were shorter but broader and somewhat larger in volume than quickly growing cells (generation time 4.9 hr).
Biological Interactions and the Realized Niche of Euplotes vannus from the Salt Marsh Aufwuchs
Authors: AILLLER WILLIAM A. , LEE JOHN J. 
Published: May 2007

SYNOPSIS. Euplotes vannus, a hypotrich ciliate. grows well over broad ranges of temperature and salinity. It requires higher densities of food (> 1 × 104 cells/ml) for rapid reproduction than do the other herbivores, the foraminiferan Al‐logromia laticollaris (> 1 × 102 cells/ml), and the nematode Chromadorina germanica (∼ 1 × 103 cells/ml), to which it was compared. If food levels were initially very high (∼ 1 × 108 cells/ml) the ciliates reproduced rapidly and consumed the algae faster than it could reproduce. Some balance between the algae and the ciliates was achieved at initial algal concentrations of ∼ 1 × 105 cells/ml. In microcosm experiments at 25 C with equal numbers of C. germanica and A. laticollaris. E. vannus proved to be a very poor competitor; reaching only 20% of control levels when grow with C. germanica and only 13% when cultured with A. laticollaris. It was a better competitor in 2‐species microcosms, at lower temperatures, and when its ratio to the other species was initially higher.The experimental evidence suggests that E. vannus is best adapted to being a migrating initial colonizer of fresh algal blooms.
Geotactic Behavior of Chlamydomonas
Authors: BEAN BARRY 
Published: May 2007

SYNOPSIS The normal negative geotaxis (motility oriented against gravity) of Chlamydomonas is an energy‐dependent response that requires coordinated flagellar activity. It is evident from quantitative assays that the rate of geotaxis is steady, and slow relative to the average swimming speed.Geotaxis is inhibited when the horizontal swimming path is less than 200 μm, suggesting that normal geotactic reorientation maneuvers involve long gradual turns. Videomicrographic tracking of cells confirms that such turns are common. In contrast, contact‐reorientations generate random cell orientations. When collision frequencies increase, geotaxis in inhibited. The mechanism of normal geotactic orientation, then, depends on long slow reorientation maneuvers (from net downward to net upward vectors) that require hundreds of micrometers of free swimming space. Mechanisms of geotaxis that would require passive reorientation or sedimentation, or rapid active responding, are excluded.Unusually dense populations sediment with atypical rapidity, probably due to formation of functionally aggregated subpopulations.Sodium azide causes an inhibition of orientation behavior that is selective relative to its effects on general motility. Evidence presented suggests that active physiologic mechanisms for geotaxis should be reconsidered.
Effects of Cyclophosphamide on Visceral Leishmaniasis in the Mouse*
Authors: HERMAN ROBERT , FARRELL JAY P. 
Published: May 2007

SYNOPSIS Cyclophosphamide (Cy), 125 or 200 mg/kg body weight, injected intraperitoneally (i.p.) into BALB/c mice one day before infection with amastigotes of Leishmania donovani, by the 8th day postinfection caused a significant decrease in the mean numbers of parasites in spleens and livers when compared to mice injected with phosphate buffered saline (PBS). When 125 mg/kg was injected into chronically infected mice (on day 34 of infection), however, within 2 days (day 36) mean parasite levels in both the spleens and livers were statistically greater than in PBS‐treated controls. Similarly, when a series of 6 Cy injections, 50 mg/kg each, was injected over a period of 8 days during the chronic stage of infection, the mean parasite levels in both spleens and livers were significantly increased over those of PBS‐treated controls. Druing the chronic stage of infection, Cy injections suppressed the immunity to superinfection.Neither plasma nor parasitized peritoneal macrophages obtained from Cy‐treated mice, when compared to PBS‐treated mice, differed in their respective capacities to influence the growth of intracellular amastigote of L. donovani in vitro. Passive transfer of hyperimmune mouse serum could not reverse the immunosuppressive effects of Cy upon chronic leishmaniasis in the mouse.It is suggested that neither readily demonstrable anti‐leishmanial humoral factors nor “immune” macrophages per se, plays a major role in acquired immunity to leishmaniasis in the mouse.
Qualitative and Quantitative Studies on DNA and RNA Synthesis in Loxodes striatus Nuclei*
Authors: RON A. , URIELI S. 
Published: May 2007

SYNOPSIS. In this study the characteristics of the synthesis of DNA and RNA in the nuclei of Loxodes were investigated. Loxodes striatus is a primitive ciliate with 2 pairs of structurally differentiated diploid nuclei, the macro‐ and micronuclei. The macronuclei are differentiated morphologically into a clearly recognizable central core and an outer zone.To determine DNA and RNA synthesis, individual organisms were analyzed by autoradiography after incubating groups of cells with a 3H‐labeled precursor ([3H]thymidine for DNA and [3H]uridine for RNA).The following observations were made: (A) All portions of macro‐ and micronuclei appeared to contain DNA as judged by the localizations of incorporated [3H]thymidine. (B) The macro‐ and micronuclei did not synthesize DNA at the same time; moreover, the duration of DNA synthesis in the former was much longer than of the latter nucleus. (C) Replication of DNA in the inner core and outer zone of the macronucleus occurred at separate times with little if any overlap. (D) All of the detectable [3H]uridine incorporation was found in the macronucleus and none in the micronucleus. Within the macro‐nucleus the central core was more heavily labeled. (E) The quantitative differences in the label of the different components of the nuclear complex were investigated. (F) Contrary to the previously reported information our results suggest that DNA synthesis can occur in adult macronuclei.The possible explanation of these results is discussed in the context of the nuclear evolution of ciliates and of recent information on nuclear differentiation.
Promitosis and Rod Occurrence in the Limax Ameba Vahlkampfia lobospinosa*
Authors: FIZER EMERSON R. , WILHELM WALTER E. 
Published: May 2007

SYNOPSIS. Nuclear division and trophozoite structure and function were investigated in Vahlkampfia lobospinosa. During karyokinesis the nucleolus remained present and divided to form polar masses. Chromatids separated and were directed to the polar masses by spindle fibers within an intact nuclear membrane. No interzonal body was formed.Trophozoites consistently contained and extruded a rod‐like structure 10–15 × 1–2 μm. Although it was found in other areas of the cell within the cytoplasm, this rod most frequently protruded from the uroid.
The Structure and Morphogenesis of the Ventral Ciliature in Paraurostyla hymenophora*
Authors: GRIMES GARY W. , L'HERNAULT STEVEN W. 
Published: May 2007

SYNOPSIS. The structure and morphogenesis of the ventral ciliature of Paraurostyla hymenophora (Stokes) are described. The oral primordium apparently originates in association with transverse cirrus #6, from which it migrates anteriorly simultaneous with kinetosomal proliferation. The primordium eventually forms an elongate ciliary field from which the future opisthe's fronto‐ventro‐transverse (FVT) and undulating membrane primordial fields arise. Concomitantly, the future proter's FVT primordial field is initiated by the disaggregation of frontal cirri #4, #5, and #6. Primordia then develop simultaneously within marginal and ventral cirral rows by a disaggregation of cirri within the respective rows, and do not give rise to new cirri until the FVT fields complete segregation into discrete cirri. Near the completion of cirral production from the FVT primordia, each ventral cirral primordium (VCP) forms the 2 rightmost transverse cirri. Segregation of new cirri within the marginal cirral primordia and VCP then occurs, eventually replacing all old cirri within their respective marginal and ventral cirral rows. At the end of cortical morphogenesis, all old ciliary organelles, with the exception of the adoral zone of membranelles, are either reorganized or replaced.These results suggest an evolutionary affinity between the ventral and marginal cirral rows and raise questions about the control of the developmental competence of individual primordia.
Intestinal Transit Time During Infection with Eimeria nieschulzi in Rats*
Authors: DUSZYNSKI D. W. , ROY S. A. , STEWERT J. , CASTRO G. A. 
Published: May 2007

SYNOPSIS. Experiments were designed to test whether or not intestinal transit time increases significantly during severe coccidiosis in the rat. Intraduodenal catheters were surgically implanted into 25 rats. Six to 12 days after surgery 11 rats were inoculated orally with 104 sporulated oocysts of Eimeria nieschulzi Dieben, and 11 were inoculated with 106 oocysts; 3 rats were retained as uninfected controls. At 2, 4, 8, 9, and 16 days postinoculation (PI) Na251CrO4 was injected through the catheter into the duodenum of fasted rats and allowed to progress through the small bowel for 15 min, at which time the rats were killed. The distribution of 51Cr in the gut was plotted as a function of gut length. The leading edge of radioactivity traversed 70% of the gut length in controls, and ∼ 50–60% in parasitized rats on days 2, 4, 8, and 9 PI. Also, a reflux of gut contents, as evidenced by radioactivity in the stomach, occurred early (PI days 2 & 4) in rats infected with 104 oocysts and throughout patency in rats infected with 106 oocysts.A 2nd study was undertaken to determine if chemically induced suppression of gut transit time during early infection would enhance infectivity as measured by increased parasite fecundity. Nine rats were injected subcutaneously with an antidiarrheal agent, Loperamide®, known to slow small bowel motility significantly. Another group of 9 control rats was injected with the ethanol‐propylene glycol solvent. Ten min after injection, all rats were inoculated per os with 104E. nieschulzi oocysts. The daily number of oocysts discharged/rat was followed from PI days 5–11. Patency began for all rats on PI day 7. The total number of oocysts discharged by the drugged rats as compared with controls was not significantly different.
Genetic Evidence Concerning the Structure of the Tetrahymena thermophila Macronucleus*†
Authors: NANNEY D. L. , PREPARATA R. M. 
Published: May 2007

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.
Eimeria malabaricas sp. n. and Eimeria bandipurensis from the South Indian Tree Squirrel, Funambulus tristriatus*
Authors: CHOWATTUKUNNEL JOSEPH T. 
Published: May 2007

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.
Correlation of Sugar Release and Concanavalin A Agglutinability with Infectivity of Symbiotic Algae from Paramecium bursaria for Aposymbiotic P. bursaria
Authors: WEIS DALE S. 
Published: May 2007

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.
Effects of Visible and Ultraviolet Light on Carotene‐deficient Mutants of Crypthecodinium cohnii
Authors: WITHERS NANCY W. , TUTTLE ROBERT C. 
Published: May 2007

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.
Observations on Gametogenesis in Plasmodium falciparum from Continuous Culture*
Authors: JENSEN JAMES B. 
Published: May 2007

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.