Understanding the choroid

Based on previous work, this paper describes the anatomical and functional characteristics of the choroidal vasculature, namely the choriocapillaris, the arterial and arteriovenous anastomosis, the segmental distribution of the short posterior ciliary arteries, and the choroidal veins. The characteristics of the choroidal innervation with reference to the sensory nerve endings are reviewed. Some features of Bruch's membrane may explain the fundoscopic and angiographic appearance of the angioid streaks and the role of its basement membranes in the formation and transport of drusen.     

1,3-Dipropyl-8-cyclopentylxanthine attenuates the NMDA response to hypoxia in the rat hippocampus

Excitatory amino acids may cause neuronal damage and death in cerebral hypoxia and ischemia, through the activation of different subtypes of glutamate receptors, in particular of the (NMDA) receptor. In the present work, the effect of hypoxia on the component of the field excitatory postsynaptic potential (fepsp) mediated by the NMDA receptor was studied in the hippocampal CA1 area of the rat. A period of 15 min of hypoxia induced virtual abolition of the NMDA receptor-mediated fepsp and a 94.8 ± 0.7% maximal decrease in the fepsp. A period of 3 min of hypoxia induced a 89.3 ± 12.3% maximal decrease in the NMDA receptor-mediated component of the fepsp and only a 50.8 ± 11.5% maximal decrease in the fepsp. Both periods of hypoxia thus induced a more pronounced depression of the NMDA receptor-mediated component of the fepsp than of the fepsp. We found that 48.5 ± 9.1% decrease (about half of the total decrease) in the NMDA receptor-mediated fepsp, and 51.6 ± 19.6% decrease (approximately all decrease) in the fepsp induced by hypoxia (3 min) were reversed in the presence of the selective adenosine A₁ receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (50 nM), and thus likely to be mediated by endogenous adenosine, through the activation of adenosine A₁ receptors. On the other hand, under the conditions we assumed to be normoxic in our slices, DPCPX (50 nM) induced a much larger increase in the amplitude of the NMDA receptor-mediated fepsp compared to the increase in the fepsp, which suggest that endogenous adenosine is inhibiting predominantly the NMDA receptor-mediated fepsp under these conditions. Hypoxia markedly decreases the NMDA receptor-mediated fepsp in the hippocampal CA₁ area. The contribution of endogenous adenosine to the inhibition of the NMDA receptor-mediated fepsp may be fundamental for its neuroprotective effects.     

烧伤后淋巴细胞膜流动性变化

报告以ＤＰＨ作为膜标记探剂，用荧光偏振法测定烧伤后淋巴细胞膜流动性变化。将小鼠背部造成１１％～１２％体表面积Ⅲ度烧伤，于伤后第６天取脾淋巴细胞，测其膜流动性。结果表明：烧伤后淋巴细胞膜流动性明显下降（Ｐ＜０．００１），同时淋巴细胞增殖反应及ＣｏｎＡ刺激的ＩＬ－２生成亦下降；淋巴细胞功能受抑制的程度与淋巴细胞膜流动性呈负相关；脾淋巴细胞膜流动性与脾组织过氧化脂质水平呈负相关。结果提示烧伤后淋巴细胞膜流动性下降可能是烧伤后淋巴细胞功能抑制的原因之一，膜流动性降低与脂质过氧化亢进有关     

“分步给药”在低氧易感患者无痛苦胃镜检查中安全性的探讨

目的 探讨在低氧易感患者无痛苦胃镜检查中采用分步给药的安全性和镇静/镇痛效果.方法 接受胃镜检查的180例患者,其中有鼾症、或咳嗽、咳痰症状的患者120例单双号随机入选Ⅰ组(分步给药组)和Ⅱ组(普通组),60例无鼾症、咳嗽、咳痰症状的患者为Ⅲ组(常规给药组),Ⅰ组采用分步给药法,Ⅲ组采用常规给药法对患者实施胃镜检查前的镇静/镇痛术,Ⅱ组则进行普通胃镜检查,分析2种镇静法对SBP、DBP、SpO2、HR、清醒时间、患者反应、患者对检查过程的感受以及是否愿意再次接受检查的影响,评价分步给药法在低氧易感患者无痛苦胃镜检查中的安全性和镇静/镇痛效果.结果 Ⅰ组、Ⅲ组检查中SBP、DBP变化无明显差异(均P＞0.05),Ⅰ组检查前、中SpO2的变化小于Ⅲ组(均P＜0.01);Ⅰ组进镜时咽部受刺激产生的恶心咽吐、流涎、咳嗽、躁动反应多于Ⅲ组(均P＜0.01),但较Ⅱ组少(均P＜0.01);Ⅰ组对胃镜检查的评价与Ⅲ组无明显差异(P＞0.05),与Ⅱ组相比有明显差异(P＜0.01).结论 分步给药法是一种适用于低氧易感患者无痛胃镜检查的安全、有效的镇静/镇痛方法.     

Antibody Response Against the Glomerular Basement Membrane Protein Agrin in Patients with Transplant Glomerulopathy

Chronic allograft nephropathy (CAN) of renal allografts is still the most important cause of graft loss. A subset of these patients have transplant glomerulopathy (TGP), characterized by glomerular basement membrane (GBM) duplications, but of unknown etiology. Recently, a role for the immune system in the pathogenesis of TGP has been suggested. In 11 of 16 patients with TGP and in 3 of 16 controls with CAN in the absence of TGP we demonstrate circulating antibodies reactive with GBM isolates. The presence of anti-GBM antibodies was associated with the number of rejection episodes prior to diagnosis of TGP. Sera from the TGP patients also reacted with highly purified GBM heparan sulphate proteoglycans (HSPG). Indirect immunofluorescence with patient IgG showed a GBM-like staining pattern and colocalization with the HSPGs perlecan and especially agrin. Using patient IgG, we affinity purified the antigen and identified it as agrin. Reactivity with agrin was found in 7 of 16 (44%) of patients with TGP and in 7 of 11 (64%) patients with anti-GBM reactivity. In conclusion, we have identified a humoral response against the GBM-HSPG agrin in patients with TGP, which may play a role in the pathogenesis of TGP.     

Sub‐retinal neovascular membrane in exudative macular degeneration

Age‐related macular degeneration is a major cause of serious vision loss. The earliest stages of age‐related maculopathy may be defined by the size of the drusen present in the macula and the effects on vision. Further manifestations may include soft drusen, choroidal neovascularisation, macular haemorrhage and cicatricial or disciform degeneration of the macula. This report describes a patient with a macular haemorrhage, a choroidal neovascular membrane and serious loss of vision. In addition, the pathogenesis, diagnosis and treat‐ment options of macular degeneration are reviewed.     

Immunobead and Density Gradient Purification of Paget Cells: In vitro Studies of Proliferation

Previous studies using primary monolayer cultures of epithelial cells from the involved epidermis of patients with mammary and extramammary Paget's disease investigated whether Paget cells proliferate as other malignant cells do. Although epithelial monolayers from the involved skin were maintained for approximately 45 days, no permanent cell lines were established. The proportion of carcinoembryonic antigen (CEA)-positive cells did not increase in the long-term cultures. Herein, we report studies of whether there is a real reduction of Paget cell numbers or if this is merely a decrease in the expression of CEA by the cells. Furthermore, we investigated whether Paget cells survive longer when cultured free from any potential inhibitory keratinocytes or other epidermal cells. Skin samples were obtained from one patient with mammary Paget's disease and three with extramammary Paget's disease; epidermal cells were cultured in vitro. An enrichment of Paget cells was carried out from the cultured epidermal cells by combining an anti-epithelial membrane antigen monoclonal antibody, binding to immunobeads, and density gradient centrifugation in Nycodenz. The separated cells were re-cultured in Keratinocyte-SFM serum-free media. The proportion of CEA-positive cells did not increase in the cultures, and the purified cells did not show any increase in survival times compared to the non-purified cultured cells. These results suggest that the decrease of CEA-positive cells noted during culture results from a decline in expression of CEA in the Paget cells. Paget cells in the involved epidermis do not proliferate significantly and thus differ from many other malignant cells.     

液膜法提取硝酸水溶液中Ag~+的工艺过程

液膜的组成为:2%石油硫醚-4%多丁二酰亚胺-94%煤油,内相试剂为:1～2mol/L的氨水溶液。较为适宜的操作条件为:乳水比为1:3;内油比为0.8:1;外相硝酸浓度为0.5～1mol/L;常温操作。当料液中的银离子浓度小于800ppm时,一次提取率可达97%以上。本工艺具有分离速度快,效率高、选择性好等优点。     

Observations on two members of the Swedish family with congenital dyserythropoietic anaemia,type III

Abstract: Two affected individuals of the Swedish family with CDA, type III, in which the disease is transmitted as an autosomal dominant character, were studied. Both cases displayed features hitherto undescribed in this family but described in patients with CDA, type III, in whom the inheritance may have been as an autosomal recessive character. Such features were: (a) haemosiderinuria, (b) grossly disorganised erythroblast nuclei, (c) differences in the ultrastructural appearances of individual nuclei within the same multinucleate erythroblast and (d) intraerythroblastic inclusions resembling precipitated globin chains. In both cases the giant mononucleate erythroblasts and the multinucleate erythroblasts had total DNA contents up to 28c (1c = haploid DNA content) and 48c respectively, and some DNA synthesising bi- and multinucleate erythroblasts contained one or more nuclei which were unlabelled with ³H-thymidine. These findings are similar to those in patients with the autosomal recessive type of disease. Thus no major phenotypic differences are yet apparent between cases of CDA, type III, with different patterns of inheritance. Analysis of the surface erythrocyte proteins of the 2 Swedish CDA, type III, patients with monoclonal antibodies recognising Band 3, glycophorins A, B, C and D, Rh, CD44, CD47, CD55, CD58, CD59, Lutheran, Kell, LW and acetylcholinesterase did not reveal any gross abnormality of expression of these proteins. A slightly altered expression of blood group antigens A and H was revealed by the lectins Dolichos biflorus and Ulex europaeus and the Mr of Band 3 as judged by SDS polyacrylamide gel electrophoresis was also slightly reduced, suggesting that there may be minor alterations in the degree of N-glycosylation of some red cell membrane constituents.     

Fluidity state of lymphocyte plasma membrane in malignant hyperthermia susceptible pigs and humans

Recent studies suggest that abnormalities occur at the lipid level in malignant hyperthermia susceptible humans and pigs. To test this hypothesis, we first investigated the physical state of plasma membranes of lymphocytes isolated from normal and malignant hyperthermia susceptible swine. In halothane-challenged pigs, malignant hyperthermia susceptibility was also assessed by ryanodine binding assay on purified sarcoplasmic reticulum membranes. The results clearly show that plasma membrane of lymphocytes from malignant hyperthermic pigs are significantly more fluid than controls. We then attempted to apply the same methodology to lymphocytes prepared from human patients previously diagnosed by the halothane and caffeine contracture test. In that case, there was no clear relationship between malignant hyperthermia susceptibility and the fluidity state of lymphocyte plasma membranes.