Differential Contractile Response of Cultured Microvascular Pericytes to Vasoactive Agents

Objective: Microvascular pericytes may contract in two different ways: In the first, a circumferential or radial mechanical force applied at right angles to the long axis of the vessel may constrict the underlying vessel affecting blood flow and transmural pressure. Retraction and elongation of pericyte processes may also occur tangentially and at right angles to the vessel axis and alter microvessel permeability by changing the amount of ablumenal surface covered or the openness of interendothelial junctions. In this study, cultured pericytes were utilized as a model experimental system to determine if vasoactive stimulation changes their shape in a manner consistent with this hypothesis. Methods: Pericytes cultured from isolated rate capillaries were subjected to angiotensin II and histamine. Their response was monitored by measuring the area of nonyielding substrate covered by the pericytes and the manner in which their shape changed. Shape changes were quantified by calculating the surface area: perimeter perimeter ratios. Results: Histamine significantly reduced surface area covered and the surface area: perimeter ratio. The pericyte processes retracted, resulting in elongated, spindle-shaped cells. These effects were nullified by the H₁ blocker diphenhydramine suggesting a receptor-specific response. Angiotensin II also elicited contraction and reduced surface area, but the cells contracted laterally and longitudinally. The surface area: perimeter ratios also decreased. Conclusions: These results indicate that pericytes are capable of two types of contractile responses in culture, depending on the specific vasoactive stimulus.     

蛇毒抗高凝状态酶、氟尿嘧啶对BEL-7404细胞作用的实验研究

目的通过蛇毒抗高凝状态酶（AHCSE）、氟尿嘧啶（5-FU）对人肝癌细胞BEL-7404（简称7404细胞）、正常LO2肝细胞（简称LO2细胞）作用的比较，研究AHCSE对肝癌的作用以及探讨其可能的作用机制。方法应用光学显微镜、透射电镜、MTT法、TUNEL、FCM等方法观察7404细胞、LO2细胞经过AHCSE、5-FU处理后，细胞形态学、生物化学等方面的变化。结果7404细胞、LO2细胞经过AHCSE、52FU处理后，发生了形态学改变；小剂量AHCSE对7404细胞具有很强的抑制作用，但对LO2细胞几乎无影响；随着剂量的加大，AHCSE对7404细胞抑制率上升不明显，但是出现对LO2细胞的抑制作用。经AHCSE作用后，7404细胞发生了凋亡，凋亡率随AHCSE浓度的增加而增加；与5-FU对7404细胞作用相似，但5-FU对LO2细胞抑制作用明显增强。结论AHCSE、5-FU对BEL-7404细胞均有很强的抑制作用，诱导细胞凋亡是其作用机制之一，AHCSE可能成为一种新的肝癌细胞凋亡的诱导剂。     

Pathogenesis of diabetic retinopathy and the renin-angiotensin system.

Despite the beneficial effects of good glycaemic control, loss of vision because of diabetic retinopathy (DR) still occurs. Recent studies have suggested that hypertension is a risk factor for the development and progression of DR and that blood pressure reduction can delay the progression of retinopathy. The renin-angiotensin system is activated by chronic hyperglycaemia, and the vitreous fluid level of angiotensin II (AII) is elevated in patients with proliferative diabetic retinopathy and diabetic macular oedema. AII increases vascular permeability and promotes neovascularization. It has been suggested that an autocrine-paracrine relationship may exist between AII and vascular endothelial growth factor in the ocular tissues. Accordingly, angiotensin-converting enzyme inhibitors or AII Type 1 (AT1) receptor blockers may be useful therapeutic agents for preventing the progression of DR.     

短期用药对幽门螺杆菌检测结果的影响

目的：研究短期不规则用药对幽门螺杆菌(Hp)检测结果的影响。方法：136名慢性胃炎及消化性溃疡的住院患，根据病史分为服药组即Hp检查前一周内接受过铅剂、抑酸剂治疗的患，共四例。对照组即Hp检查前未接受过药物治疗的患考，共37例。Hp检查方法包括①血清学方法；②快速尿素酶试验(RUT)；③组织学方法；④13c—尿素呼气试验(13C—UBT)。结果：服药组RUT，组织学，13C—UBT方法Hp检出率分别为9．0％，21．2％，27．3％，均显低于对照组相应Hp检出率37．8％、40．5％、48．6％(P＜0．01，P＜0．05，P＜0．05)。两组血清学方法Hp IgG、IgM阳性率各为48．5％，51．5％和54．1％，54．1％(P＞0．05)。单独服用质子泵抑制剂组RUT，组织学方法Hp检出率4．0％，16．0％显低于对照组相应方法Hp检出率(P＜0．01，P＜0．05)。单独服用枸橼酸铋钾、H2受体拮抗剂患中各方法Hp检出率与对照组检出率无显性差异(P＞0．05)。单独服用枸橼酸铋钾、H2受体拮抗剂、质子泵抑制剂三组Hp感染率14．3％、15．0％、16．0％均显低于对照组Hp感染率46．0％(P＜0．05)。结论：Hp检查前短期使用铋剂、抑酸剂可导致Hp检出率下降，短期使用质子泵抑制剂可显降低RUT、组织学方法Hp检出率；各方法中快速尿素酶试验检出率最低。血清学方法检测Hp抗体不受药物影响。     

单甲氧聚乙二醇化学修饰药物酶的研究进展

用单甲氧基聚乙二醉(1)化学修饰药物酶是生化药物研究开发的重要手段之一。本文综述了1化学修饰药物酶的一般方法及修饰后酶在生物和理化性质方面的变化，同时对1研究前景进行展望，并指出了尚待解决的问题。     

Dose-response differences in the ability of ramipril to improve retention in diabetic mice

Ramipril blocks the conversion of angiotensin I to II. The literature indicates that diabetes is often associated with mild impairment of learning and memory. The study reports the effects of ramipril on memory retention in diabetic and non-diabetic mice. Mice were made diabetic by an injection of streptozocin. After overt signs of diabetes were present, diabetic or vehicle-treated mice were partially trained on a footshock active avoidance task. Immediately after training, ramipril (0.5–1.5 mg/kg s.c.) was administered and retention was tested by continuing training one week later until mice avoided footshock on five out of six trails. The results indicate that ramipril enhanced retention of both diabetic and control mice but it required about 5 times as much ramipril in diabetic as control mice to achieve the same effect on retention. Increased sensitivity to angiotensin II may play a role in cognitive impairment in diabetes.     

Characteristics of antibody responses induced in mice by protein allergens

Whereas many foreign proteins are immunogenic, only a proportion is also allergenic, having the capacity to induce the quality of immune response necessary to support the production of IgE antibody. We have demonstrated previously that intraperitoneal administration to mice of proteins such as ovalbumin (OVA) or the industrial enzyme A. oryzae lipase, which possess significant allergenic potential, stimulates the production of both IgG and IgE antibody. Identical exposure to bovine serum albumin (BSA), a protein with limited potential to cause immediate respiratory or gastrointestinal hypersensitivity reactions, induced IgG responses only. In the current investigations, the quality of immune responses induced following exposure to these proteins via mucosal tissue (intranasal) has been compared with those provoked following administration via a non-mucosal (intraperitoneal) route of exposure. Intranasal or intraperitoneal administration of BSA, OVA or A. oryzae lipase elicited in each case vigorous IgG and IgG1 antibody responses. For all three proteins, at every concentration tested, and via both routes of exposure, IgG1 antibody titres paralleled closely IgG titres. However, the three materials displayed a differential potential to provoke IgE responses and this correlated with their known allergenic potential in humans. Thus, OVA and A. oryzae lipase stimulated strong IgE antibody responses, whereas BSA provoked low titre IgE only at the highest concentration tested (5% administered intraperitoneally). The quality of induced responses was not affected by the route of exposure. It would appear, therefore, that the stimulation of IgG and IgG1 antibody responses is a reflection of protein immunogenicity whereas protein allergenicity is associated with the induction of strong IgE responses.     

蛇毒治疗不能解释肺动脉高压的研究

本通过对不能解释的肺动脉高压患，进行右心导管测定肺动脉平均压（ＰＡＭＰ）作为主要对照指标，观察蛇毒制品（精制溶栓酶）的急性药物试验和近期药物试验。发现该药物在近期有理想的降低ＰＡＭＰ作用，症状及胸片、超声心动图异常也明显取得改善，提示其可能为治疗该病的理想药物。     

重症胰腺炎动物模型制作及发病机理的研究

为探讨胰腺炎的发病机理，作者采用大鼠（ｎ＝５８只）十二指肠结扎法和犬（ｎ＝４６条）胰管内注射自身胆汁法制作重症胰腺炎的动物模型。该模型接近人类急性胰腺炎的发病因素，方法可靠，操作简便，费用便宜。前者适用于小动物实验，后者宜于大动物实验。作者认为胰管内压力增高和微生物是急性胰腺炎的重要条件；胰酶激活始动时间早在胰管内胆汁和肠液的反流后，胰酶激活的主要部位在腺泡细胞。     

左室肥厚对急性心肌梗塞时心肌酶的影响

通过２０例有左室肥厚和２３例无左室肥厚患者发生急性心肌梗塞时ＣＰＫ值的比较，发现在梗塞部位相同的情况下，心肌肥厚组的酶值水平高于非心肌肥厚组（１３．２±４．８比９．０±４．６Ｕ／ＬＰ＜０．０１），这可能与肥厚组酶活力增强和心肌梗塞体积增大有关。