摘要:

SYNOPSIS.Striking progress in our understanding of parasitic protozoa has been achieved thru the employment of advanced electron‐microscopic, biochemical, immunologic, and cultivation methods. Some recent information gathered by means of these methods on trichomonad and trypanosomatid flagellates as well as on eimeriidian and plasmodiid haemosporiidian Sporozoa is discussed. It is emphasized that the parasitic protozoa when studied by the presently available sophisticated methods in the context of being parasites, not merely cells maintained on refined media, can aid us greatly in illuminating the highly complex functional aspects of host‐parasite interacti

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02114.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.The structure of the cortical region (epicyte and ectoplasm) of the gregarineLecudina pellucida, an intestinal parasite of the polychete wormPerinereis cultriferawas studied by electron microscopy.The epicitary folds have 3 unit type membranes. Between the 1st and 2nd is a layer probably composed of fine longitudinal fibrils which has an arch‐like or gutter‐like structure at the crest of the folds. Inside these folds is cytoplasm without any noticeable differentiation or inclusion except for a granular (or finely fibrillar) layer under the limiting inner membrane and close to it.The ectoplasmic zone of the entocyte is separated from the epicitary region by a lengthwise discontinuous cylindrical opaque layer, inwardly tangential to the folds. The ectoplasm lacks paraglycogen granules but has various organelles: apparently pinocytic vesicles against the wall between the folds, vesicles with myelinic membranes, opaque granules, a few mitochondria with blistered internal vesicles, and a few circular tubular fibers.The superficial zone of the gregarine is supposed to contribute to nutrition, thru the extensive surface furnished by its folds and thru the pinocytic vesicles; but this alimentary intake is incomplete compared with that of the previously studied anterior region.Insufficient mucus is discharged to account for locomotion. There are some circular ectoplasmic fibers, but locomotory myonemes are completely absent. However, there are deformations of the folds and corresponding waves that could account for locomotion by creeping or swimming. These movements of the folds might be due to the action of the contractile proteins and correspond with some of the layers seen in the w

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02115.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Culture methods favorable for conjugation inStentor coeruleusare described and the effects of conjugation on over 12,000 conjugating pairs ofS. coeruleusare presented.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02116.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.A method is described for cultivation of large numbers ofSpirostomum ambiguum, calcified intracellularly with hydroxyapatite (bone salt deposits). The structure and activity of living animals at various stages of calcification is described and also illustrated with unstained and silver impregnated ciliates. A suitable modification of von Kossa's method for localization of insoluble phosphate deposits is given.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02117.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Only well fedParamecium aurelia, grown either monoflorally or on a mixture of 2 species of bacteria, are adequate to maintain optimal fission rates and encystment rates forDidinium nasutum.Progressive starvation of paramecia prior to their being fed to didinia leads to decreased fission rates, the appearance of abnormal cells and a loss of ability to encyst by the didinia. This depression can be fully overcome by allowing the didinia to feed again upon well nourished paramecia. A minimum of 45 well‐fed paramecia is required daily for eachDidiniumif maximal fission rates are to be maintained. Encystment and fission appear to be mutually exclusive processes, but encystment rates are related to fission rates and seem to be exclusive of the density of the didinial cultur

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02118.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.A strain ofPodophrya fixa(O. F. Müller, 1786) isolated in 1964 from a stagnant pool in the vicinity of Haifa, Israel, was cultivated in mass cultures and in single clones. It produced smooth‐walled cysts, and also the previously described ring‐walled cysts. The process of excystment, not previously reported, is described here in de

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02119.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Sulfanilamide inhibited the growth ofO. malhamensis.Sulfanilamide growth inhibition was reversed competitively by PABA and by very high concentrations of folic acid. Folic acid at low concentrations, however, accentuated sulfa inhibition of growth. Vitamin B12, methionine,p‐aminobenzoylglutamic acid and pteroic add were effective to some extent as antagonists of sulfa. A marked reduction in the folate synthesis was accompanied by sulfa growth inhibition. This was restored on growth restoration by PABA, folic acid, vitamin B12and methionine. The reduction in folate synthesis held for all the folate fractions except one derivative—a formyl poly‐glutamate. Sulfanilamide‐inhibited cells had a considerable activity forin vitrosynthesis of folate activity from precursors. ∼75% activity being retained at the 90% growth inhibition level. There was no change in chlorophyll, RNA and DNA contents as a result of sulfa growth i

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02120.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Eimeria larimerensiswas found in 5 species of ground squirrels and the white‐tailed prairie dog. The hosts includedSpermophilus armatusfrom Utah and Montana,S. variegatusfrom Utah,S. tridecemlineatusfrom Wyoming,S. lateralisfrom Utah,S. beecheyifrom California andCynomys leucurusfrom Wyoming. Oocysts were not present in fecal samples ofS. richardconifrom Montana,S. lateralisfrom California orS. columbianusfrom Washington. This coccidium could not be experimentally transmitted toS. richardsoni; however, patent infections were established inS. armatus, S. lateralis, andS. variegatus.No infections were found after inoculation of least chipmunks (Eutamius minimus), Mongolian gerbils (Meriones unguiculatus), or laboratory rats even tho excystation occurred in these animals. Resistance to infection did not develop during repeated experimental infections ofS. armatus, S. lateralis, orS. variegatus.No outward signs of coccidiosis were seen in any of the experimentally infected animals.In experimentally infectedS. armatus, the prepatent period was 5 days, and the patent period lasted 3–7 (mean 6.5) days. The endogenous stages were located in the epithelial cells of the jejunum and ileum. Mature 1st‐generation schizonts, 1st seen 2.5 days after inoculation, contained 16–32 merozoites. Mature 2nd generation schizonts were present 3.5 days after inoculation and contained 22–46 merozoites of a larger size than those of the 1st generation. Gametocytes were 1st seen 3.5 days after inoculation and developing oocysts were present 4 days after inoculation. Macrogametes contained eosinophilic granules which coalesced to form the oocyst wall. Formation of the macrogametes took place around cytoplasmic masses within the microga

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02121.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Density of prey (Paramecium aurelia) and predator (Amoeba proteus) were varied while volume of inorganic medium was kept constant. Variations in density of prey had little effect on the rates of feeding and reproduction of the amoebae; but with increasing predator density the amoebae captured the paramecia less rapidly and ingested fewer before dividing, altho division size did not change appreciably. Therefore, amoebae of a low density population with a constant food supply carry more nutritional reserves from generation to generation than do those in a denser population.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02122.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Two new species of chonotrichous ciliates,Oenophorachona ectenolaemusn.g., n.sp. andSpirochona halophilan.sp. were found onAnisogammarussp. collected from the waters of Humboldt County, California and Argyle Bay, San Juan Island, Washington. This is the 1st reported occurrence of 2 genera of chonotrichous ciliates on a single host species as well as the 1st of the occurrence ofSpirochonain marine and brackish water environments.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02123.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY