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51.
The intestinal epithelium of third-stage larvae and adults of Cystidicoloides ephemeridarum from haemocoel of mayflies and stomach of brown trout was studied by electron microscopy and cytochemistry. In section, the intestine of both stages is composed of a single layer of about ten undifferentiated intestinal cells in a ring. A labyrinth of deep invaginations is present in the basal region of each cell. The apical surface is modified into well developed, regularly arranged microvilli. These, together with numerous organelles engaged in metabolism and a well defined gut lumen filled with unidentifiable material suggest that the intestine may function in digestion and absorption during both stages. The adults seem to feed upon the semifluid content of the stomach of brown trout. Fortuitous oral infection with undetermined bacteria in vitro led to degenerative changes in the intestinal tissue and probably caused death of the infected specimens. Up to 75% of the cell volume in the L3 is occupied by glycogen deposits. In the adults, a minor portion of glycogen, together with lipid droplets, has been observed. The adults are considered to rely more on aerobic metabolism, whereas anaerobic metabolism (glycolysis) may prevail in L3. 相似文献
52.
Frantiek Moravec Isaure de Buron Tiffany G. Baker David González-Solís 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2008,53(4):382-391
Three gonad-infecting species of Philometra Costa, 1845 were, for the first time, recorded from perciform fishes from estuarine and marine waters in South Carolina and
Georgia, USA: Philometra charlestonensis sp. nov. from the scamp Mycteroperca phenax (Jordan et Swain) (Serranidae), P. saltatrix Ramachandran, 1973 from the bluefish Pomatomus saltatrix (Linnaeus) (Pomatomidae), and Philometra sp. from the Atlantic croaker Micropogonias undulatus (Linnaeus) (Sciaenidae). The new species is characterized mainly by males (body length 2.65–3.14 mm) with equally long, needle-like
spicules (length 132–141 μm) and the gubernaculum (81–93 μm) bearing dorsal transverse lamella-like structures on its distal
portion, the body length of gravid females (168–247 mm), the presence of a well-developed anterior bulbous inflation on the
female oesophagus, and by the length of the first-stage larvae (544–597 μm). A key to gonad-infecting species of Philometra parasitizing marine and brackish-water fishes is provided. 相似文献
53.
J Bia?ek A Denys M Kowalska T Szyd?owska 《Archivum immunologiae et therapiae experimentalis》1985,33(6):735-739
The influence of ISO, the antiviral drug of immunomodulating activity, on the course of experimental influenza infections and mixed, viral-bacterial infections was studied. Spleen leukocytes migration inhibition test, performed in vitro in the presence of specific antigens stimulating influence of the drug administered to the infected animals was observed. 相似文献
54.
Protein kinase was found to be precipitated from adenovirus type 12 (Ad12)-infected KB cells and Ad12-transformed hamster cells by sera of tumor-bearing hamsters and rats: Immunoprecipitates obtained with T antigen reactive sera catalyzed transfer of 32P from [γ-32P]ATP to the γ-chain of IgG. Analogous products of control cells were without significant activity. Control hamster sera precipitated no protein kinase from infected and transformed cells. Some control rat sera (syngeneic with immune sera), however, were found to precipitate protein kinase from infected and transformed cells; particularly active in this respect were sera of female breeder rats. When partially purified, highly immunoreactive T antigen preparations from transformed cells were used as a source of enzymatic activity, protein kinase was detected only in precipitates obtained with immune sera. 相似文献
55.
Telomeres, besides their main role in the protection and maintenance of chromosome ends, have several other vital functions
in the cell cycle. We studied their role in the achiasmatic meiosis of female Lepidoptera, insects with holokinetic chromosomes.
By fluorescence in-situ hybridization (FISH) with the insect telomeric probe, (TTAGG)
n
, we mapped the distribution of telomeric and interstitial telomeric sequences (ITS) in female meiotic chromosomes of two
species, Orgyia antiqua with a reduced chromosome number (2n=28) and Ephestia kuehniella mutants, possessing a radiation-induced chromosome fusion in the genome (2n=59). In addition to the strong typical telomeric signals, O. antiqua displayed weaker hybridization signals in interstitial sites of pachytene bivalents. The observed ITS most probably reflect
remnants of chromosomal rearrangements and support the hypothesis that the Orgyia karyotype had arisen by multiple fusions of ancestral chromosomes. On the other hand, the absence of ITS in the chromosome
fusion of Ephestia indicated the loss of telomeres before the two original chromosomes fused. When the telomeric probe was amplified by enzymatic
reaction with tyramid, the number of ITS observed increased in Orgyia, and a few ITS were also observed in several chromosomes of Ephestia but not in the fused chromosome. This suggests that the genomes of both species also contain ITS other than those originating
from chromosome fusions. The analysis of female meiotic prophase I revealed non-homologous associations of postpachytene bivalents
mediated by telomeric DNA, which were not observed in the pachytene stage. Surprisingly, in early postpachytene nuclei the
telomeric associations also involved ITS, whereas later postpachytene nuclei displayed chains of bivalents interconnected
only by true telomeres. This finding favours a hypothesis that telomeric associations between bivalents play a role in chromosome
segregation in the achiasmatic meiosis of female Lepidoptera.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
56.
57.
Neuropeptide Y in the female reproductive tract of the rat. Distribution of nerve fibres and motor effects 总被引:2,自引:0,他引:2
The spontaneous firing of single neurones in the region of the lateral reticular nucleus was the subject of a pharmacological study employing microiontophoretic and systemic application of adrenoceptor agonists and antagonists. Both iontophoretic noradrenaline and systemic clonidine depressed neuronal firing. The depressions were consistently reversed by the alpha-2 antagonist RX781094. Other adrenergic antagonists, prazosin and sotalol, were ineffective. The results suggest the existence of alpha-2 receptors in this region of the brain. 相似文献
58.
J Bia?ek A Denys M Kowalska I Ciebiada T Szyd?owska 《Archivum immunologiae et therapiae experimentalis》1989,37(3-4):421-430
This paper is the continuation of earlier studies on the effect of the killed suspension of Corynebacterium parvum in influenza virus infected mice. Our investigation showed the normalized effect of these drugs on disturbed function of cell mediated immunity during experimental influenza infection especially in phagocytic and bactericidal activity of granulocytes. The present experiments concern the explanation of these infection mechanisms. Intraperitoneal injection of Corynebacterium parvum stimulated spleen index. Foot pad test is higher than in comparatively treated BCG group. The pathomorphological analysis of the spleen, thymus and peritoneal lymph nodes points out to the multiplication of multiple lymph nodes sinus cells. Generally, C. parvum possessed protective effect in experimental influenza infection. We tested the following parameters: phagocytic and bactericidal activity of granulocytes, liberation of leukocytes migration inhibition factor (LIF). 相似文献
59.
Bogdan Karakašević 《Medical microbiology and immunology》1955,142(1):27-37
Ohne Zusammenfassung 相似文献
60.