Lysozyme Activity in the Plasma of Rodents Infected With Their Homologous Trypanosomes

Background

In this study the concentration of lysozyme in blood plasma of Microtus agrestis, Clethrinomys glareolus, Apodemus sylvaticus, BK rats and outbred white mice before and after infection with culture forms of Trypanosoma microti, T, evotomys, T. grosi, T. lewisi and T. musculi respectively was measured.

Methods

Blood samples of rodents, Microtus agrestis, Clethrionomys glareolus, Apodemus sylvaticus, BK rats and outbred mice infected with T. microti, T. evotomys, T. grosi, T. lewisi and T. musculi respectively were collected in heparinized micro- tubes immediately before inoculation and 3, 6, 12, 24, 48, 96 and more than 400 days after intra- perituneal inoculation with 5×10⁵of their homologous trypanosome parasites of which more than half were metacyclic trypomastigote in 0.2 ml of culture medium. Micro- tubes were centrifuged and plasma samples were separated and the lysozyme activity was measured by the agar method.

Results

Levels of lysozyme rose rapidly three to six days after the inoculation to ten to twenty than their pre- infection levels. They then gradually decreased, although after more than one year they were still two to ten folds higher than controls. The highest level measured occurred in rats infected with T. lewisi and the lowest in A. sylvaticus infected with T. grosi. After one year the highest concentration of lysozyme was in mice infected with T. musculi and lowest in A. sylvaticus.

Conclusion

Persistent enhanced lysozyme levels may prevent re- infection with trypanosomes.     

Fetal erythropoiesis in steel mutant mice. III. Defect in differentiation from BFU-E to CFU-E during early development

Erythroid progenitor cells in +/+ and Sl/Sld fetal livers manifested as burst-forming units-erythroid (BFU-E) and colony-forming units- erythroid (CFU-E) were assayed in vitro during early development. The proportion of BFU-E was higher as mutant than in normal fetal livers. On the other hand, the proportion of CFU-E was less in the mutant than in the normal. These results suggest that the defect in Sl/Sld fetal hepatic erythropoiesis is expressed at the steps of differentiation that effect the transition from BFU-E to CFU-E.     

Prevalence and predictors of Toxoplasma seropositivity in women with and at risk for human immunodeficiency virus infection

We assessed the prevalence and predictors of latent Toxoplasma infection in a large group of human immunodeficiency virus (HIV)-infected and HIV-uninfected at-risk US women. The prevalence of latent Toxoplasma infection was 15% (380 of 2525 persons) and did not differ by HIV infection status. HIV-infected women aged > or =50 years and those born outside of the United States were more likely to have latent Toxoplasma infection, with prevalences of 32% and 41%, respectively.     

种植牙——人类的第三副牙齿

研究显示,若全口无牙,人的全身机能将下降40％～60％,佩戴假牙之后,全身机能也只能恢复到正常的81％-95％．种植牙的诞生为彻底解决缺牙带给患者咀嚼功能和语言发音障碍,影响面容美观和心理伤害等长期困扰其健康和生活质量问题提供了一个重要出路．伴随技术的成熟,种植牙也因此被誉为继乳牙、恒牙之后,人类的第三副牙齿．它是生命科学和材料与工程科学完美结合所诞生的产物,是近半个世纪以来口腔医学献给人类健康的一份厚礼．种植牙作为天然牙齿的替代体,人工牙根可以和牙床完全融合,     

Severe cholestatic hepatitis following cloxacillin treatment

We describe a 77-year-old woman who developed fatigue, fever, a maculopapular rash and severe cholestatic hepatitis two weeks after receiving cloxacillin and ofloxacin.     

Neonatal treatment with 192 IgG-saporin produces long-term forebrain cholinergic deficits and reduces dendritic branching and spine density of neocortical pyramidal neurons

The role of basal forebrain-derived cholinergic afferents in the development of neocortex was studied in postnatal rats. Newborn rat pups received intraventricular injections of 192 IgG-saporin. Following survival periods ranging from 2 days to 6 months, the brains were processed to document the cholinergic lesion and to examine morphological consequences. Immunocytochemistry for choline acetyltransferase (ChAT) and in situ hybridization for ChAT mRNA demonstrate a loss of approximately 75% of the cholinergic neurons in the medial septum and nucleus of the diagonal band of Broca in the basal forebrain. In situ hybridization for glutamic acid decarboxylase mRNA reveals no loss of basal forebrain GABAergic neurons. Acetylcholinesterase histochemistry demonstrates a marked reduction of the cholinergic axons in neocortex. Cholinergic axons are reduced throughout the cortical layers; this reduction is more marked in medial than in lateral cortical areas. The thickness of neocortex is reduced by approximately 10%. Retrograde labeling of layer V cortico-collicular pyramidal cells reveals a reduction in cell body size and also a reduction in numbers of branches of apical dendrites. Spine densities on apical dendrites are reduced by approximately 20-25% in 192 IgG- saporin-treated cases; no change was detected in number of spines on basal dendrites. These results indicate a developmental or maintenance role for cholinergic afferents to cerebral cortical neurons.      

肿瘤坏死因子对牛肺动脉内皮细胞的损伤及蛋白激酶C抑制剂的抑制作用

研究表明:肿瘤坏死因子(TNF)可剂量依赖地引起牛肺动脉内皮细胞乳酸脱氢酶释放率(LDH%)升高,促进中性粒细胞向内皮细胞粘附,并可抑制内皮细胞增殖和DNA合成。蛋白激酶C(PKC)抑制剂1-(5-异喹啉磺酰基)-2-甲基哌嗪(H-7)和槲皮素一方面可剂量依赖地抑制TNF对内皮细胞的直接损伤,另方面又可通过抑制TNF诱导的中性粒细胞对内皮细胞粘附增加,减轻TNF对内皮细胞的间接损伤作用,同时还可抑制TNF对内皮细胞增殖和DNA合成的影响,从而间接加强内皮细胞对损伤的自我修复。