Cutaneous allergy to mustard in a salad maker

A case of allergic contact dermatitis to mustard (Brassica nigra) in a salad maker is reported. The sources of skin contact included a commercial salad cream, a vinegrette, and various members of the mustard family, Cruciferae. The Cruciferae family includes many salad vegetables and condiments which contain allergenic isothiocyanates. The extent of skin contact among salad makers and other food handlers may be significant, and sensitization to isothiocyanates from this large family of vegetables may be an important cause of food contact allergy in these individuals.     

Understanding how Listeria monocytogenes targets and crosses host barriers

Human listeriosis is caused by the Gram-positive bacterium Listeria monocytogenes. In humans, this pathogen has the ability to cross the intestinal, placental and blood-brain barriers, leading to gastroenteritis, maternofetal infections and meningoencephalitis, respectively. The entry of L. monocytogenes into cultured human epithelial cells is mediated by the interaction of an L. monocytogenes surface protein, internalin, with its human receptor, E-cadherin. The internalin-E-cadherin interaction is species-specific, and relies on the nature of a single amino-acid in the E-cadherin molecule, which is proline in permissive species such as humans, and glutamic acid in non-permissive species such as the mouse. In a transgenic mouse model that expresses human E-cadherin in enterocytes, internalin allows L. monocytogenes to cross the intestinal barrier. Epidemiological evidence also supports a role for internalin in human listeriosis, not only for crossing the intestinal barrier, but also for targeting and crossing the placental and blood-brain barriers. Consistent with these epidemiological data, infection with L. monocytogenes of trophoblastic cell lines, primary trophoblast cultures and human placental villous explants demonstrates that bacterial invasion of the syncytiotrophoblast barrier is mediated by the internalin-E-cadherin interaction, leading to histopathological lesions that mimic those seen in the placentas of women with listeriosis. Thus, the internalin-E-cadherin interaction that plays a key role in the crossing of the intestinal barrier in humans is also exploited by L. monocytogenes to target and cross the placental barrier. Further investigations are currently focusing on the molecular mechanisms by which L. monocytogenes targets and crosses the blood-brain barrier.     

大鼠创伤性肠粘连模型的制备及黄厚排气颗粒对其粘连程度的影响

为筛选出操作方法简便，结果稳定可控的大鼠创伤性肠粘连模型，观察中药复方黄厚排气颗粒对其粘连程度的影响，选用SD大鼠，手术造成肠粘连模型，用中药复方2．5、5．0、10．0g/kg连续治疗7d后观察肠粘连程度。结果表明，以盲肠型动物模型的制备较为理想，手术易于操作，结果稳定可控。用中药复方治疗后模型动物的肠粘连程度得到明显改善。提示黄厚排气颗粒对术后肠粘连有一定的预防作用。     

Evidence for differential effects of 8-OH-DPAT on male and female rats in the Anxiety/Defense Test Battery

The Proxemics/Activity test and the Eat/Drink test, two components of the Anxiety/Defense Test Battery, were developed to measure defensive reactions to situations associated with a natural predator (cat). In the present studies the behavioral effects of 8-OH-DPAT treatment (0.01–1.0 mg/kg, SC) were entirely consistent with anxiety/fear reduction. These effects included an increase in time spent near the cat compartment, and a complimentary decrease in time spent farthest from this compartment, together with an increase in transits and locomote behavior. 8-OH-DPAT (1.0 mg/kg) also increased eat frequencies and durations (highly preferred food) both during and following cat presentation, without influencing drinking. This finding is discussed with reference to previous findings with 8-OH-DPAT in studies assessing both food intake and anxiolysis. Interestingly, 8-OH-DPAT was more potent in a majority of its effects in female subjects, a finding consistent with recent neurochemical data. These findings provide important behavioral evidence for a sexual differentiation in 5-HT function, and support the case for greater emphasis on female subjects in animal models of anxiety.Supported by NIH MH42803 and RCMI Grants RR03061 and RR01825     

Chicken Parathyroid Hormone Gene Expression in Response to Gastrin,Omeprazole, Ergocalciferol,and Restricted Food Intake

Treatment with omeprazole, a long-acting proton pump inhibitor of acid secretion, induces hypergastrinemia. In chickens, omeprazole induces growth not only of the acid-producing mucosa (probably reflecting the trophic action of gastrin), but also of the parathyroid glands (hypertrophy + hyperplasia), while suppressing bone density and body weight gain without affecting blood calcium. The first part of the present study was concerned with the effect of omeprazole, ergocalciferol (vitamin D₂), and restricted food intake on the gene expression of parathyroid hormone (PTH) in the parathyroid glands of the chicken. Chickens were treated with omeprazole (400 μmol/kg/day, I.M.), food restriction, omeprazole + food restriction, ergocalciferol (250 000 IU/kg/day, S.C.), or ergocalciferol + omeprazole for 5 weeks. The weight gain of the chickens was monitored, and the weights of the parathyroid glands and femurs were determined at sacrifice. PTH mRNA in the parathyroid glands was analyzed by Northern blot. The second part of the study examined the effect of 3 weeks of continuous gastrin infusion (chicken gastrin 20–36, 5 nmol/kg/hour, S.C.) on the expression of PTH mRNA in the parathyroid glands. Omeprazole reduced the body weight and femur density (ash weight per volume) while greatly increasing the weight of the parathyroid glands and the PTH gene expression. Food restriction alone and ergocalciferol alone (at a dose that raised blood Ca²⁺) were without effect, but food restriction greatly enhanced the omeprazole-evoked increase in parathyroid gland weight and PTH gene expression. Gastrin increased the weight of the parathyroid glands and reproduced the effect of omeprazole on PTH gene expression. Hence, it seems likely that the effect of omeprazole reflects the ensuing hypergastrinemia. Received: 6 August 1996 / Accepted: 23 April 1997     

Effect of concomitant food intake on absorption kinetics of fenoldopam (SK&F 82526) in healthy volunteers

Summary Eight healthy volunteers participated in an open crossover study to assess the effect of a standardised meal on the systemic availability of a single oral dose of fenoldopam mesylate 100 mg. Subjects were studied on four separate occasions, twice fasting and twice fed in randomised, balanced order. Plasma and urine samples were obtained before and at regular intervals up to 25 h post dose. Measurement of fenoldopam (SK&F 82526) and its 8-sulphate metabolite (SK&F 87782) were by means of HPLC-EC analysis. Area under the plasma concentration time curve (AUC) and maximum detected plasma concentration (C_max) for fenoldopam and SK&F 87782 were significantly reduced whereas time to maximum concentration was significantly increased with food. Using AUC's for fenoldopam and SK&F 87782, mean relative bioavailabilities were 35% and 81% respectively under fed compared with fasting conditions. Twenty-four hour excretion of fenoldopam was significantly reduced with food, but excretion of SK&F 87782 was apparently unchanged. Mean relative bioavailabilities calculated from these data were 83% and 86% respectively. Relatively large inter-subject variability in AUC and C_max were seen, but intra-subject variability was not marked. Mild symptoms associated with vasodilation were reported on all study days.     

脑动静脉畸形实验动物模型的建立

脑动静脉畸形是一种比较常见的严重威胁人们生命安全和生存质量的脑血管疾病，目前人们主要是通过尸体解剖以及CT、MRI等影像学的方法认识。近年来，学者们应用各种动物模型来研究脑动静脉畸形的血流动力学，病理生理学以及脑动静脉畸形栓塞材料的评估，栓塞后临床疗效评价，放射照射剂量对脑动静脉畸形的影响等。本文就脑动静脉畸形实验动物的常用种类，动物模型的建立方法以及动物模型的实际应用进行了综述。     

激素性股骨头缺血坏死MRI诊断的实验研究

目的：建立股骨头缺血坏死(ANFH)动物模型，将磁共振成像(MRI)表现与组织病理学结果对照，探讨早期ANFH的病理变化和删表现的病理学基础。方法：成年新西兰兔36只，随机均分成三组。A组：为正常对照组，静脉注射生理盐水。B、C组为实验组，B组：单纯静脉注射地塞米松10mg／kg／d连续7天，间隔两周再重复一次。C组；马血清与激素共用，先静脉注射马血清10g／kg，间隔2周再重复一次；继之重复B组给药。之后4、8、16、26周后分别从3组随机各取3只，先拍X线平片再进行删，然后取双侧股骨头做组织病理检查。结果：实验组兔股骨头第8周T1WI信号强度明显降低，T2WI呈不均匀高信号，对应病理改变为骨髓水肿，骨髓腔内少量出血和少量骨细胞坏死。16、26周T1WI信号强度增高，病理显示骨髓脂肪细胞肥大并融合成大泡状，大量骨细胞坏死，骨小梁变细、中断。16、26周兔股骨头X线平片示骨质稀疏，骨小梁模糊。C组上述变化较B组显著。结论：1．采用马血清和肾上腺皮质激素共用，比单纯用肾上腺皮质激素更易诱导出较典型的ANFH动物模型。2．删能够较全面反映早期激素性ANFH的病理变化。     

骨质疏松动物实验骨折风险性分析

目的:评价骨质疏松动物模型发生骨折的风险性.方法:健康雌性SD大鼠36只,随机分为实验组和对照组各18只.实验组切除双侧卵巢,对照组仅切开皮肤.于术后2、4、8周两组处死6只大鼠,作松质骨(腰椎)和皮质骨(股骨干)骨密度(BMD)组织形态学和力学测定.结果:与对照组相比,手术组松质骨BMD 2、4、8周均明显下降,2周皮质骨无明显差异,4、8周则明显下降;股骨中段骨皮质厚度变薄;骨小梁体积(TBV)占全部骨组织体积(TTV)的百分比明显减少;成骨细胞和破骨细胞明显增多;股骨最大弯曲载荷、腰椎最大压缩载荷下降.