Morphological characteristics and immunohistochemical detection of nicotinic acetylcholine receptors on intestinofugal afferent neurones in guinea-pig colon

Intestinofugal afferent neurones (IFANs) provide excitatory synaptic input to abdominal prevertebral ganglion neurones. Input is greatly reduced during blockade of nicotinic acetylcholine receptors (nAChRs) in the wall of the colon, suggesting two projection pathways: a direct pathway without synaptic interruption and an indirect pathway interrupted by at least one nicotinic cholinergic synapse. This study aimed to characterize the morphology of IFANs and examine the distribution of nAChRs on them. We identified IFANs in guinea-pig colon by retrograde labelling with fluorescent tracer DiI placed either on the lumbar colonic nerves in vitro or inferior mesenteric ganglion in vivo. Confocal laser scanning microscopy and computerized image-processing software were used for 3D image reconstruction. Approximately 70% of identified IFANs had Dogiel type I-like morphology, the remainder were Dogiel type II-like. In vivo labelled IFANs were injected with Lucifer Yellow and immunostained for nAChRs using monoclonal antibody MAb35. Approximately 3% of total plasma membrane surface of IFANs with Dogiel type I morphology had MAb35-IR. In contrast, <1% of membrane surface of IFANs with Dogiel type II morphology had MAb35-IR. The finding that IFANs displayed immunostaining for nAChRs suggests the presence of putative nicotinic synapses.     

Synergistic actions of the vitamin D analogue MC 1288 and 15-deoxyspergualin in xenotransplantation

Abstract: The vitamin D analogue MC 1288 (20-epi-1α,25-dihydroxycholecalciferol) effectively postpones rejection of cardiac, intestinal, skin, and aortic allografts. MC 1288 binds to the vitamin D receptor and is thus assumed to exert its immunosuppressive effects via the same mechanisms as 1α,25-dihydroxycholecalciferol, the active form of vitamin D. 1α,25-Dihydroxycholecalciferol has been demonstrated to inhibit the production of various cytokines (interleukin-2, interferon-γ, granulocyte macrophage colony-stimulating factor, and interleukin-12) and to prevent B lymphocyte secretion of immunoglobulins. In the present study MC 1288 was evaluated for its ability to prevent rejection of mouse-to-rat cardiac xenografts, alone and in combination with 15-deoxyspergualin (DSG). Combined treatment with MC 1288 (given days -1 to 9) and DSG (given day -1 and onward) postponed rejection from day 3.0 (untreated recipients) until day 19.5. In rats treated with MC 1288 or DSG as monotherapy, rejection occurred after 3.0 and 7.5 days, respectively. Functioning grafts, obtained on day 9 from recipients treated with MC 1288 and DSG in combination, displayed an almost normal morphology without any obvious deposition of immunoglobulins in the vessels of the grafts and with just a few infiltrating cells. Thus, we have demonstrated synergistic actions of MC 1288 and DSG in delaying rejection of xenografts. Analysis of cellular infiltration, immunoglobulin deposition and graft survival times in the various treatment groups indicate a combined inhibitory effect of these two drugs on the level of macrophage effector function, direct or indirect via T lymphocytes, as well as on antibody production.     

Effect of dietary selenium and vitamin E on the biomechanical properties of rabbit bones

Summary It is generally agreed that combined deficiency of selenium and vitamin E leads to several abnormalities including Kashin-Beck disease which is an endemic and chronic degenerative osteoarthrosis. The abnormalities can be reversed by the administration of various forms of selenium and vitamin E.The present study was designed to investigate the effects of dietary selenium and vitamin E on bone tissue and on the biomechanical properties of bone. Young rabbits of both sexes were fed with either a selenium- and vitamin E-adequate diet (control group), or a selenium- and vitamin E-deficient diet or a selenium-excess diet. The selenium-deficient diet resulted in a significant decrease in plasma selenium level and the selenium-excess diet resulted in a significant increase in the plasma selenium level with respect to the corresponding control values (p<0.05). The diets did not affect the blood cell counts considerably but erythrocyte glutathione peroxidase activity increased (decreased) relatively when the plasma selenium level increased (decreased) (p<0.05). The light microscopic investigations of the bone tissues of the two experimental groups indicate that the findings of the present work are compatible with osteomalacia. The biomechanical properties of the bones from the three groups were determined experimentally with bending tests. Both the Se-and vitamin E-deficient diet and the Se-excess diet decreased the biomechanical strength of the bones significantly while the bones belonging to the control group always had the largest modulus of elasticity (p<0.05).     

Rh phenotype prediction by DNA typing and its application to practice

The complexity of the RHD and RHCE genes, which is the greatest of all blood group systems, confounds analysis at the molecular level. RH DNA typing was introduced in 1993 and has been applied to prenatal testing. PCR-SSP analysis covering multiple polymorphisms was recently introduced for the screening and initial characterization of partial D. Our objective is to summarize the accrued knowledge relevant to the approaches to Rh phenotype prediction by DNA typing, their possible applications beyond research laboratories and their limitations. The procedures, results and problems encountered are highly detailed. It is recommended that DNA typing comprises an analysis of more than one polymorphism. We discuss future directions and propose a piecemeal approach to improve reliability and cost-efficiency of blood group genotyping that may eventually replace the prevalent serology-based techniques even for many routine tasks. Transfusion medicine is in the unique position of being able to utilize the most extensive phenotype databases available to check and develop genotyping strategies.     

Axonal transport of dopamine D1 receptors in the rat brain

Binding of a specific dopamine D₁ receptor antagonist,¹²⁵I-SCH 23982, was measured in rat brain sections by quantitative autoradiography at various time intervals, following a knife cut through the striatonigral pathway. Twenty-four hours after lesioning, accumulations of D₁ receptor binding sites were found in sagittal sections both rostral and caudal to the lesion site. No other regions studied (caudate-putamen, nucleus accumbens, olfactory tubercle, and substantia nigra pars reticulata) showed any change in D₁ receptor binding 24h after the lesion. In brain sections obtained 10 days after lesioning, only the substantia nigra pars reticulata had a significant decrease in D₁ receptors ipsilateral to the lesion. These findings suggest the possibility of a presence of bidirectional axonal transport of D₁ receptors in rat striatonigral pathway.     

Vitamin D and HRT: No benefit additional to that of HRT alone in prevention of bone loss in early postmenopausal women. A 2.5-year randomized placebo-controlled study

The study was designed to examine the effect of hormone replacement therapy (HRT) and low-dose vitamin D (Vit D) supplementation on the prevention of bone loss in non-osteoporotic early postmenopausal women and to determine whether Vit D supplementation can give additional benefit to an already optimized estrogen regimen. The effects of HRT and Vit D on bone mineral density (BMD) were studied in postmenopausal women in a 2.5-year randomized placebo-controlled study. The study population was a subgroup of the Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) (n=13100). A total of 464 early postmenopausal women were randomized to four groups: (1) HRT (a sequential combination of 2 mg estradiol valerate and 1 mg cyproterone acetate (E₂Val/CPA); (2) vitamin D₃ (cholecalciferol, 300 IU/day); (3) HRT+Vit D; and (4) placebo (calcium lactate; 93 mg Ca²⁺/day). Lumbar (L1–4) and femoral neck BMD were determined by dual-energy X-ray absorptiometry before and after 2.5 years of treatment. After 2.5 years, lumbar BMD had increased by 1.8% in the HRT group (p<0.001) and by 1.4% in the HRT+Vit D group (p=0.002), whereas lumbar BMD had decreased by 3.5% (p<0.001) in the Vit D group and by 3.7% (p<0.001) in the placebo group. The loss of femoral neck BMD was lower in the HRT (–0.3%) and the HRT+Vit D (–0.9%) groups compared with the Vit D (–2.4%) and the placebo groups (–3.7%). This study confirms the beneficial effect of HRT on BMD. It also shows that low-dose vitamin D supplementation has only a minor effect in the prevention of osteoporosis in non-osteoporotic early postmenopausal women and does not give any benefit additional to that of HRT alone.     

复合维生素对抗体形成细胞的影响

单独一种维生素缺乏对免疫功能的影响已有较多研究报道,但维生素缺乏一般不会单独发生,为此本实验研究了维生素A、E、B_2、B_6及叶酸供给不足(1/3生理需要量)、加倍补充(2倍和3倍生理需要量)后对小鼠抗体形成细胞的复合效应。动物喂养6周(不足纠正组喂8周),结果显示,不足组抗体形成细胞显著低于对照组,而2倍、3倍组则显著升高,不足组补充正常量维生素后,抗体形成细胞升高超过对照组,与2倍量组无显著差异;另外,该几种维生素对肝脏RNA、脾脏DNA、RNA及肝脏蛋白质均有明显影响,且抗体形成细胞的变化与核酸、蛋白质含量改变相平行,提示后者可能是维生素作用于体液免疫系统的生化机制。     

Three-dimensional recording of the human face with a 3D laser scanner.

Three-dimensional recording of the surface of the human body or of certain anatomical areas has gained an ever increasing importance in recent years. When recording living surfaces, such as the human face, not only has a varying degree of surface complexity to be accounted for, but also a variety of other factors, such as motion artefacts. It is of importance to establish standards for the recording procedure, which will optimise results and allow for better comparison and validation. In the study presented here, the faces of five male test persons were scanned in different experimental settings using non-contact 3D digitisers, type Minolta Vivid 910). Among others, the influence of the number of scanners used, the angle of recording, the head position of the test person, the impact of the examiner and of examination time on accuracy and precision of the virtual face models generated from the scanner data with specialised software were investigated. Computed data derived from the virtual models were compared to corresponding reference measurements carried out manually between defined landmarks on the test persons' faces. We describe experimental conditions that were of benefit in optimising the quality of scanner recording and the reliability of three-dimensional surface imaging. However, almost 50% of distances between landmarks derived from the virtual models deviated more than 2mm from the reference of manual measurements on the volunteers' faces.     

Malnutrition and subsequent ischemic heart disease in former prisoners of war of world war II and the Korean conflict

The harsh treatment of former prisoners of war (POWs) of World War II and the Korean conflict resulted in severe malnutrition. Although rarely linked to specific long-term medical problems, a specific marker of malnutrition, self-reported lower limb edema (presumably due to a vitamin B deficiency) was associated with a three-fold increase in subsequent death attributed to ischemic heart disease (IHD) during the follow-up period from 1967 through 1975. Although there is at present no medical basis for linking edema, which is perhaps a marker for some unmeasured risk factor, to subsequent IHD, this finding may nonetheless have medical implications for the group of former POWs and other populations with severe dietary deficiency. It also suggests there may be a need to reexamine currently held theories on malnutrition and subsequent chronic disease.     

北方汉族人群维生素D受体基因Bsm I位点多态性与前列腺癌易感性的相关性分析

目的 :研究低发病的中国汉族人群维生素D受体基因 (VDRG)BsmⅠ 位点单核苷酸多态性 (SNP)与前列腺癌的关系 ,探讨不同种族前列腺癌发病的基因差异。　方法 :收集中国北方地区汉族人群 10 3例前列腺癌病人及10 6例健康对照者外周血标本 ,应用变性高效液相色谱 (DHPLC)检测VDRG第 8内含子BsmⅠ多态位点 ,并对该位点SNP分布进行分析。　结果 :BsmⅠ 多态位点bb、Bb、BB基因型和等位基因在北方地区汉族前列腺癌病人及对照者中的分布频率差异无显著性 (P >0 .0 5 ) ,基因型分布频率分别为 92 .2 3%、7.77%、0和 94.34 %、5 .6 6 %、0 ;等位基因B、b分别为 3.88%、96 .12 %和 2 .91%、97.0 9%,而与高发病人群的分布相比有显著不同。　结论 :VDRGBsmⅠ多态性在低发病的中国汉族人群与前列腺癌无相关 ,其分布与高发病人群有明显差异 ,提示VDRGBsmⅠ多态性可能是前列腺癌发病种族差异的原因之一。