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The metacercariae of Pharyngostomum cordatum were found naturally infected in the European grass snake, Rhabdophis tigrina, purchased from a local snake collector in Jinju, Kyongsangnam-do. They were experimentally fed to several kinds of animals such as mice, rats, hamsters, ducklings, a dog, and cats. The adult worms were recovered from the cats 5 weeks after the infection, but none from other animals. The measurements and other morphological characters of the metacercariae and adults were both compatible with those of P. cordatum described by previous authors. The present study confirmed that the snake, Rhabdophis tigrina, serves as a second intermediate (or paratenic) host of P. cordatum in Korea.  相似文献   

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Intratracheal inoculation of Echinococcus multilocularis protoscoleces was performed in prednisolone tertiary-butylacetate(PTBA)-treated and untreated golden hamsters and AKR/J mice. Repeated PTBA treatments prior to the day of inoculation prevented the influx of neutrophils against the cestode. More than 1 month after infection, living immature adult forms of E. multilocularis, showing some somatic prolongation, were recovered from the pulmonary alveolar space of PTBA-treated golden hamsters, in the absence of any cystic development.  相似文献   

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Neonatally thymectomized rodents present an increased susceptibility to experimental viral infections leading to a severe growth depression. In thymectomized mice, viral infections significantly enhance the appearance of the wasting syndrome. These data suggest that viral infections may contribute to the development of wasting syndrome.  相似文献   

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Quinine, a cinchona alkaloid, was investigated for putative anxiogenic activity in view of clinical reports suggesting that it induces anxiety and apprehension following its use in malaria. The experimental paradigms chosen to elucidate anxiogenic activity have been shown to stand the tests of reliability and validity. Yohimbine, which has been shown to induce anxiety both in animals and in man, was used for comparison. Quinine was found to elicit a complex behavioural profile of activity ranging from overt central stimulation to marked central depression on dose increment. The doses 10 and 20 mg/kg, ip, of quinine chosen to investigate anxiogenic activity were comparable to those induced by 2.5 and 5 mg/kg ip of yohimbine. Quinine induced a dose-related anxiogenic activity in the open-field and elevated plus-maze tests in mice, and the social interaction and thirst conflict tests in rats, similar to effects induced by yohimbine. In addition, both quinine and yohimbine attenuated the effects of diazepam, an anxiolytic agent, in the open-field and thirst conflict tests. The results indicate that quinine exerts significant anxiogenic effect at a particular dose range.  相似文献   

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EHb-a herbo-mineral formulations of iron (ferrous form) produced a significantly higher and dose dependent increase in the haemoglobin level, as compared to Fefol (a non-complex-chelated iron preparation). Also, EHb did not produce any overt toxicity or gastric irritation at these dose levels. The results suggest that EHb can be of a better choice in the treatment of anaemia than any other commercially available chelated iron preparations.  相似文献   

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Laboratory investigations on three aquatic populations of Galba truncatula, originating from the Peruvian Altiplano and French Massif Central, were carried out during three successive snail generations to determine if these populations might be successfully used for the metacercarial production of Fasciola hepatica under experimental conditions. High numbers of surviving snails at day 30 post-exposure (>70%), high prevalences of F. hepatica infections (>60%), and prolonged productions of cercariae for a mean period of 35 to 47 days were observed in the three populations, whatever the snail generation. In the Peruvian population, metacercariae of F. hepatica significantly decreased in numbers from a mean of 251 in the parent snails to 124 per snail in the F2 generation, whereas no significant variation was observed in the two French populations. As these aquatic snails rarely emerged out of water, the use of these populations for the commercial production of F. hepatica metacercariae was of great interest, because the daily time spent watching the breeding boxes of snails was clearly shorter, thereby reducing the cost of producing metacercariae compared with using amphibious snails reared with romaine lettuce.  相似文献   

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ABSTRACT

Trophoblast migration and invasion through the decidua and maternal uterine spiral arteries are crucial events in placentation. During this process, invasive trophoblast replace vascular endothelial cells as the uterine arteries are remodeled to form more permissive vessels that facilitate adequate blood flow to the growing fetus. Placentation failures resulting from either extensive or shallow trophoblastic invasion can cause pregnancy complications such as preeclampsia, intrauterine growth restriction, placenta creta, gestational trophoblastic disease and even maternal or fetal death. Consequently, the use of experimental animal models such as rats and mice has led to great progress in recent years with regards to the identification of mechanisms and factors that control trophoblast migration kinetics. This review aims to perform a comparative analysis of placentation and the mechanisms and factors that coordinate intrauterine trophoblast migration in humans, rats and mice under physiological and pathological conditions.  相似文献   

10.
峨眉双蝴蝶的胚胎学研究   总被引:5,自引:0,他引:5  
首次报道了峨眉双蝴蝶Tripterospermum cordatum(Marq.)H.Smith的胚胎学特征,研究结果用以讨论双蝴蝶属的系统演化关系。主要研究结果如下:花药四室;药壁发育为双子叶型;绒毡层属单型起源,细胞具单核,属腺质型绒毡层,药隔处的绒毡层细胞形成类胎座,其余部位的绒毡层细胞仍为一层细胞;在花药成熟时,花药的药室内壁纤维状如厚且柱状伸长,表皮细胞减缩退化,纤维状加厚不明显。成熟花  相似文献   

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Emigration of leukocytes from the circulation into tissue by transendothelial migration, is mediated subsequently by adhesion molecules such as selectins, chemokines and integrins. This multistep paradigm, with multiple molecular choices at each step, provides a diversity in signals. The influx of neutrophils, monocytes and lymphocytes into inflamed tissue is important in the pathogenesis of chronic inflammatory bowel disease. The importance of each of these groups of adhesion molecules in chronic inflammatory bowel disease, either in human disease or in animal models, will be discussed below. Furthermore, the possibilities of blocking these different steps in the process of leukocyte extravasation in an attempt to prevent further tissue damage, will be taken into account.  相似文献   

13.
自身免疫性胰腺炎(autoimmune pancreatitis,AIP)是一种特殊类型的胰腺炎,其发病机制与自身免疫密切相关。2010年公布的诊断标准主要从血清学、影像学、组织学、胰腺外器官受累和激素治疗反应五方面将其分为1型和2型。近年来越来越多的资料显示多种胰腺外表现与AIP相关,如泪腺和唾液腺病变,硬化性胆管炎,间质性肺炎,肺门、纵膈淋巴结肿大,腹膜后纤维化,肾小管间质性肾炎等。胰腺外病变与AIP有相同的病理表现:器官内可见大量的Ig G4阳性浆细胞浸润,对激素治疗反应良好。本文主要对AIP的胰腺外表现作一综述。  相似文献   

14.
The sympathetic nervous system has been shown to influence immune function. Angiotensin II and substance P are two neurally active peptides that have been shown to increase sympathetic nervous system activity when injected centrally. Using osmotic minipumps, we chronically infused angiotensin II (1 microgram/h) and substance P (2 micrograms/h) into the brains of intact Sprague-Dawley rats for a period of 1 month and 2 weeks, respectively. Age-matched control animals were infused with artificial cerebrospinal fluid. We then examined the effect of this infusion on the percentage of different lymphocyte populations in the peripheral blood. The angiotensin II infused animals showed an increase in the percentage of total T-cells and a decrease in the percentage of B-cells relative to controls. The substance P treated animals also showed an increase in the percentage of T-cells present, but failed to show the decrease in the B-cell population seen with the angiotensin II infused group. This study shows that the central nervous system can influence the immune system. As shown in this study, these effects are most likely mediated via the sympathetic nervous system. These results add to the expanding body of data suggesting an important role of the central nervous in regulating immune function and our susceptibility to disease.  相似文献   

15.
峨眉双蝴蝶组织培养与快速繁殖(简报)   总被引:2,自引:0,他引:2  
峨眉双蝴蝶植株带芽茎段的最佳芽诱导培养基为MS+6-BA 1.5mg/L;在1/2MS+IBA 1.0培养基上可诱导出根,生根率96%以上;生根苗经炼苗后移栽成活率在89%以上。  相似文献   

16.
In order to obtain skin and ocular lesions comparable to those which are found in human onchocerciasis, it is not necessary to use members of the genus Onchocerca which are found in large animals and difficult to use. Other Filariae with biological features comparable to Onchocerca volvulus can be used in which microfilariae are localized in capillaries and can escape from the walls and produce lesions similar to those in onchocerciasis. The life cycles of several filariae of rodents have been worked out and they are proposed as experimental models as the tick vectors and the rodent hosts are easily maintained in the laboratory.  相似文献   

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Ethanolic extract of the aerial parts of H. spinosa a semiwoody herb was examined on male albino rats for certain haematological changes. The extract (100 & 200 mg/kg, po) significantly increased the haemoglobin, haematocrit, RBC and total WBC, as compared with vehicle treated control rat haemogram. In anemic male albino rats, the extract significantly increased haemoglobin, haematocrit and RBC count. Serum iron and serum total iron binding capacity were significantly decreased in H. spinosa extract treated anemic rats as compared with those in the vehicle treated anemic control rats. These findings demonstrated the haematinic effect of H. spinosa extract on experimental animals.  相似文献   

20.
Aparisthmium cordatum (Juss.) Bail. (Euphorbiaceae), known in the State of Pará, Brazil as "ariquena queimosa", is a medium-sized tree which is native to the North Brazilian coastal region. Previous phytochemical studies of the bark of A. cordatum yielded a furan diterpenoid with a clerodane skeleton, called aparisthman. Recently, we reported the antiulcerogenic activity of trans-dehydrocrotonin (DHC), a furan diterpene isolated from Croton cajucara bark, in different ulcerogenic models in mice and rats. The aim of the present study was to assess the possible antiulcerogenic activity of aparisthman. When previously administered (p.o.) at the dose of 100 mg/kg(-1), aparisthman reduced significantly (p < 0.01) gastric injury induced by the indomethacin/bethanechol (71%), ethanol (71%), pylorus ligature, (59%) and hypothermic restraint-stress models (50%), in mice and rats. In the HCl/ethanol-induced gastric ulcer model in mice, at oral doses of 100 and 250 mg/kg(-1), aparisthman from A. cordatum reduced significantly (p < 0.001) the formation of gastric lesions by 59% and 66%, respectively, as compared with control. In the pylorus-ligature model, aparisthman (p.o.) decreased the volume of gastric juice as compared with control (p < 0.001). When aparisthman (100 mg/kg(-1)) was administered intraduodenally to mice, significant modifications were found, such as a decrease in gastric acidity as compared with control. In the animals pre-treated with aparisthman, free mucus production increased by 19% in the gastric mucosa (p < 0.05). The results suggest that aparisthman from A. cordatum presents a significant anti-ulcer effect when assessed in these induced ulcer models. Although the mechanism underlying this antiulcerogenic effect remains unknown, it seems to be related to an increase of the defensive mechanisms of the stomach such as prostaglandin synthesis and mucus production. The good yield of aparisthman obtained from A. cordatum, as well as its antiulcerogenic activity, suggest that this compound should be submitted to pharmacological research as a potential new antiulcerogenic drug.  相似文献   

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