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排序方式: 共有123条查询结果,搜索用时 15 毫秒
1.
L B Hejfets L A Levina L V Salmin A A Antonova L S Segal M L Kuzminova K M Slavina A V Vasileva 《Journal of hygiene, epidemiology, microbiology, and immunology》1976,21(3):292-299
A total of 3 controlled field trials were carried out. One of them (1963) showed that aerosol chemical typhoid vaccine did not protect vaccinated subjects from the disease. Two other tests (1964 and 1965) assessing the effectivity of killed orally administered typhoid vaccine revealed a short term (up to 3 months) protective effect expressed by an effectivity coefficient of 45%, fiducial limits being 8-70%. In the assessment of oral paratyphoid B vaccine, the difference in morbidity in the experimental and control groups was statistically insignificant due to a small number of cases of disease. 相似文献
2.
Vesela Yancheva Elenka Georgieva Stela Stoyanova Iliana Velcheva Dóra Somogyi Krisztián Nyeste László Antal 《Acta zoologica》2020,101(4):431-446
The present study aimed to investigate for the first time the health status of the Caucasian dwarf goby Knipowitschia caucasica (Berg, 1916, Fishes of freshwaters of Russian Empire, p. 563, Moscow, Russia: Dep. Zemledeliya) (Teleostei: Gobiidae) from an anthropogenically loaded site in Hungary using histopathological analyses on multiple tissues. For that purpose, fish were collected from the public beach at Tiszafüred near the River Tisza. Gills, liver and kidney were subjected to histopathological analyses, and the results showed different alterations in each organ, which also differed in their extent and severity. In addition, we also found lesions in the reproductive organs of both, male and female fish which, overall, we hypothesized could be due to untreated municipal wastewaters, most likely contaminated with endocrine-disrupting chemicals. The multi-organ histopathological analyses of Caucasian dwarf gobies revealed different lesions, prevalence and severity in each target organ, as follows: liver>gills>kidney>gonad (testes and ovaries). These histopathological lesions can be assessed as good indicators of contamination by endocrine-disrupting chemicals of freshwater ecosystems. 相似文献
3.
This article considers the influence of the hydrological regime in the lower reaches of the Volga delta (based on the example of the Damchiksky site of the Astrakhan Reserve) during high water periods in the low-water year of 2012 and medium-water year of 2013 on the abundance of producers entering for spawning and the density of aggregations of juveniles of roach Rutilus caspicus, vulgaris rudd Scardinius erythrophthalmus, and river perch Perca fluviatilis. It is shown that the fish mass spawning in 2013 was more effective and occurred on floodplain spawning areas with the sequential succession of the investigated species, while the fish spawning was observed in eriks and was less effective in 2012. It was revealed that vulgaris rudd shows the highest adaptation to insufficient watering conditions. 相似文献
4.
Biliana Nikolova Severina Semkova Iana Tsoneva Georgi Antov Juliana Ivanova Ivanina Vasileva Proletina Kardaleva Ivanka Stoineva Nelly Christova Lilyana Nacheva Lyudmila Kabaivanova 《Engineering in Life Science》2019,19(12):978-985
Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all chemotherapy drugs currently on the market cause serious side effects. Fortunately, several studies have shown that some non‐toxic biological macromolecules, including algal polysaccharides, possess anti‐cancer activities or can increase the efficacy of conventional chemotherapy drugs. Polysaccharides are characteristic secondary metabolites of many algae. The efficacy of polysaccharides on the normal and cancer cells is not well investigated, but our investigations proved a cell specific effect of a newly isolated extracellular polysaccharide from the red microalga Porphyridium sordidum. The investigated substance was composed of xylose:glucose and galactose:manose:rhamnose in a molar ratio of 1:0.52:0.44:0.31. Reversible electroporation has been exploited to increase the transport through the plasma membrane into the tested breast cancer tumor cells MCF‐7 and MDA‐MB231. Application of 75 µg/mL polysaccharide in combination with 200 V/cm electroporation induced 40% decrease in viability of MDA‐MB231 cells and changes in cell morphology while control cells (MCF10A) remained with normal morphology and kept vitality. 相似文献
5.
Voitova A. A. Dmitrieva M. D. Dymova M. A. Vasileva N. S. Nushtaeva A. A. Richter V. A. Kuligina E. V. 《Russian Journal of Bioorganic Chemistry》2019,45(6):783-792
Russian Journal of Bioorganic Chemistry - Brain tumors are among the most intractable types of malignant neoplasms. Despite advances in the treatment of cancer, in particular, the development of... 相似文献
6.
Dimitrova Yana D. Georgiev Boyko B. Mariaux Jean Vasileva Gergana P. 《Systematic parasitology》2019,96(3):279-297
Systematic Parasitology - Two new cestode species of the family Hymenolepididae Perrier, 1897 are described from birds of the order Passeriformes at Wondo Genet, Ethiopia. Passerilepis zimbebel n.... 相似文献
7.
Phyllobothrium squali Yamaguti, 1952 is redescribed and illustrated on the basis of the holotype from Squalus acanthias from Japanese waters and specimens from the same host off the Bulgarian Black Sea coast (new geographical record). The species is characterised by: a scolex diameter of 2.9-4.3 mm, a glandular apical organ, foliose bothridia with folded and posteriorly bifid margins, accessory suckers of 286-367 micro m in diameter, 222-373 testes per proglottis, an oval cirrus-sac with a length of 354-655 micro m, the vagina opening anteriorly to the cirrus-sac, and the terminal part of vagina with a circular musculature. Specimens from Etmopterus spinax off Naples, Mediterranean Sea, recorded by Euzet (1959) as Crossobothrium squali, are redescribed and their identification not confirmed. P. squali is recognised as a specific parasite of S. acanthias; it is presently known only from Japanese waters, the Black Sea and the Irish Sea. Changes to the generic diagnosis of Phyllobothrium, as given by Ruhnke (1996a), are proposed in order to include the characters of P. squali. 相似文献
8.
9.
We report sphingolipid-related reorganization of gel-like microdomains in the plasma membrane of living Saccharomyces cerevisiae using trans-Parinaric acid (t-PnA) and 1,6-diphenyl-1,3,5-hexatriene (DPH). Compared to control, the gel-like domains were significantly reduced in the membrane of a sphingolipid-deficient lcb1-100 mutant. The same reduction resulted from sphingolipid depletion by myriocin. The phenotype could be reverted when a myriocin-induced block in sphingolipid biosynthesis was bypassed by exogenous dihydrosphingosine. Lipid order of less-ordered membrane regions decreased with sphingolipid depletion as well, as documented by DPH fluorescence anisotropy. The data indicate that organization of lateral microdomains is an essential physiological role of these structural lipids. 相似文献
10.
Kovacheva VP Mellott TJ Davison JM Wagner N Lopez-Coviella I Schnitzler AC Blusztajn JK 《The Journal of biological chemistry》2007,282(43):31777-31788
During gestation there is a high demand for the essential nutrient choline. Adult rats supplemented with choline during embryonic days (E) 11-17 have improved memory performance and do not exhibit age-related memory decline, whereas prenatally choline-deficient animals have memory deficits. Choline, via betaine, provides methyl groups for the production of S-adenosylmethionine, a substrate of DNA methyltransferases (DNMTs). We describe an apparently adaptive epigenomic response to varied gestational choline supply in rat fetal liver and brain. S-Adenosylmethionine levels increased in both organs of E17 fetuses whose mothers consumed a choline-supplemented diet. Surprisingly, global DNA methylation increased in choline-deficient animals, and this was accompanied by overexpression of Dnmt1 mRNA. Previous studies showed that the prenatal choline supply affects the expression of multiple genes, including insulin-like growth factor 2 (Igf2), whose expression is regulated in a DNA methylation-dependent manner. The differentially methylated region 2 of Igf2 was hypermethylated in the liver of E17 choline-deficient fetuses, and this as well as Igf2 mRNA levels correlated with the expression of Dnmt1 and with hypomethylation of a regulatory CpG within the Dnmt1 locus. Moreover, mRNA expression of brain and liver Dnmt3a and methyl CpG-binding domain 2 (Mbd2) protein as well as cerebral Dnmt3l was inversely correlated to the intake of choline. Thus, choline deficiency modulates fetal DNA methylation machinery in a complex fashion that includes hypomethylation of the regulatory CpGs within the Dnmt1 gene, leading to its overexpression and the resultant increased global and gene-specific (e.g. Igf2) DNA methylation. These epigenomic responses to gestational choline supply may initiate the long term developmental changes observed in rats exposed to varied choline intake in utero. 相似文献