摘要:

SYNOPSIS.Unusual dense forms were discovered in ultrathin sections ofPlasmodium berghei‐infected rat erythrocytes. These parasites frequently occurred with one or more typical trophozoites in a single blood cell. They appeared darker than both the neighboring trophozoites and the host erythrocyte. Ribosomes were visible in clusters in their compact cytoplasm. The endoplasmic reticulum, when present, had dilated cisternae often containing a material of low density. Large food vacuoles werecommonly seen along with the small vesicles harboring pigment granules. The single large nucleus had dense nucleoplasm. Multilaminated membraned bodies and sausage‐shaped vacuoles were, seen in some of the parasites.The exact identity of this form ofP. bergheiis not known. Its possible significance is discussed with particular reference to the differentiation of gametocy

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03279.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.Eimeria bateri, a parasite of the Indian quail, was described from laboratory infections in Japanese quail. First generation schizonts developed in the glands of the duodenum and upper intestine. Second, 3rd and 4th generation schizonts and gametocytes occurred in the villous epithelium. There was a gradual spread along the small intestine until the whole organ was affected. The prepatent period was 4 days and the patent period 6 days. Graded doses from 5,000 to 1,280,000 oocysts produced very little pathogenic effect in young quail.E. bateridid not infect young pheasants or chicks.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03280.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.The transformation of theP. cynomolgioocyst into definitive sporozoite forms occurs 8–10 days after an infective blood meal byAnopheles, stephensimosquitoes. Vacuolization divides the oocyst cytoplasm into sporoblast sub‐units from which sporozoites bud. The role of sporoblast nuclear and cytoplasmic components in the complex differentiative process is discus

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03281.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.The feasibility of applying immunoferritin technics in malarial antibody studies was explored using the asexual erythrocytic stages ofPlasmodium berghei.Anti‐P. bergheiantibodies were induced in rats by repeated infection and in rabbits by immunization with French press‐ or saponin‐prepared antigens. Ferritin tagging was observed in thin sections of some freed and intracellularP. bergheiparasites after exposure to ferritin‐labeled antibodies.A more extensive localization of ferritin was observed in cells subjected to the indirect versus the direct method of incubation. With formalin as a prefixative as opposed to glutaraldehyde, an increased ferritin tagging and the distribution of ferritin at intracellular sites was evident. These observations are discussed in terms of the damage and associated increase in permeability which often appeared in our formalin‐fixed tissue.Controls with normal serum or normal uninfected erythrocytes differed in ferritin localization from their corresponding test materials in only a few trials. The need for antibody preparations as free as possible from reactivity to host components became obvious. The positive results obtained when ferritin alone (especially TC‐modified ferritin) was applied in excess indicated a nonspecific binding and the necessity of purifying the conjugates of unbound ferritin was stressed.Native ferritin was found in the large double membranebound host inclusions, small vesicles and residual body o

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03282.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03283.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.Allamanda nereifoliaandPlumeria rubra, plants belonging to the family Apocynaceae were infected experimentally with the trypanosomatid flagellate,Phytomonas elmassiani.In these presumably exotic hosts,P. elmassiani, ordinarily infecting plants belonging to the family Asclepiadaceae, underwent marked structural changes. The presence of numerous choanomastigote like organisms along with a certain proportion of promastigotes and amastigotes, would, under ordinary circumstances, result in classification of the infecting organisms asCrithidia.Obviously, the change in environment from Asclepiadaceae to the closely related Apocynaceae, exerts a profound influence on structure of the organism.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03284.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.Myxosoma cephalisn. sp. is described from the brain meninges, gills, jaw bone, crop tissue and buccal cavity ofMugil cephalusLinnaeus (striped mullet) of south Florida. The fresh spore is subspherical in front view, lenticular in side view and averages 14.1 × 11.0 × 9.0 μ (length, width, thickness). The sutural ridge is broad, the sutural line is faintly visible and the polar filaments are coiled 4–5 times. This parasite is apparently associated with an epizootic in mullet.Three species of beloniform fishes from south Florida waters were examined for myxosporidan parasites. New host records and extensions of ranges are provided forMyxidium sphaericumThélohan inStrongylura timucu(Walbaum) (timucu), andCeratomyxa aggregataDavis inHyporhamphus unifasciatus(Ranzani) (halfbeak). A single spore of the genusMyxidiumwas found in the gall bladder ofHemiramphus brasiliensisLinnaeus (ball

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03285.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.Differentiation of small‐mouthed cells (microstomes) into large‐mouthed, potentially carnivorous cells (macrostomes) inTetrahymena voraxis prevented by 2‐mercapto‐1‐(β‐4‐pyridethyl) benzimidazole (MPB). This differentiation, induced by the transforming principle, stomatin, isolated from the potential prey,Tetrahymena pyriformis, is a synchronous process in which 70–95% of the population ofT. voraxmicrostomes transform into macrostomes within 450 min. MPB also inhibits RNA synthesis in transforming microstomes while having little effect on protein synthesis. Finally, the effect of MPB on both transformation and RNA synthes

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03286.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.Feeding activity ofHomalozoon vermiculareonParameciumandBlepharismaand on a number of non‐living materials was compared in order to understand its feeding behavior and some of the factors governing it. During a given period it involves a series of feeding responses, each response being completed in 5 stages: (i) contact of prey or non‐living particles with the oral rim ofHomalozoon, (ii) ejection of toxin byHomalozoon, if the food is a living organism, (iii) paralysis of the prey, (iv) grasping, and (v) swallowing.The feeding activity ofHomalozoondiffers from one food to another and also on any one food at different times. These differences are governed by (i) the physiologic condition ofHomalozoonand (ii) certain food characteristics. Its starvation, but not its developmental stage, markedly influences its feeding activity on any food. The food characteristics most important for feeding byHomalozoonare: (i) concentration of prey or non‐living particles in the medium, insuring their adequate contact with the organism's mouth, (b) susceptibility of living organisms to paralysis by the toxin, (c) suitability of particle size for accommodation in the organism's mouth, and (d) suitability of the food material to stimulate the grasping and swallowing responses.Homalozoonmuch prefersParameciumtoBlepharismaon account of (i) a greater susceptibility ofParameciumto paralysis by the toxin, and (ii) certain differences in the chemical characteristics of the certain proteins, particularly albumins, hemoglobin, etc., of the 2 orga

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03287.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SYNOPSIS.Uniformly14C‐labeled pyrimidine ribonucleosides and orotic‐6‐14C acid were fed to growing cultures ofOchromonas malhamensisand the radioactivity appearing in RNA and DNA was determined. The carbon skeletons of uridine and cytidine were incorporated intact into all of the pyrimidine nucleotides from RNA and DNA. Incorporation of radioactivity into the purine nucleotides was negligible. The evidence supports the conclusion that deoxyribonucleotide biosynthesis in this organism proceeds via a pathway involving the direct reduction of the corresponding ribonucleosides or ribonucleotides. An important role for a trans‐N‐deoxyribosylase in deoxyribonucleotide biosynthesis here appears to be

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1971.tb03288.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY