Cytokines and growth factors in keratinocytes and sweat glands in chronic venous leg ulcers. An immunohistochemical study

The role of growth factors and cytokines in the impaired healing of chronic leg ulcers remains uncertain. The aim of this study was to determine whether changes in the amount and location of cytokines and growth factors may be associated with impaired healing in chronic leg ulcers. Biopsies from leg ulcers of 21 patients and from normal skin of nine healthy volunteers were examined immunohistochemically for selected growth factors and cytokines. Greater staining intensity was found in keratinocytes at the edges of ulcers compared to normal skin, or skin adjacent to the ulcers. Staining at the ulcer edge was more intense in nonhealing ulcers for only vascular endothelial growth factor and platelet-derived growth factor, whereas staining in the adjacent skin was more intense for all factors in the nonhealing phase. For all factors staining was cytoplasmic, suggesting production in these areas. This study shows up-regulation of the production of cytokines and growth factors in keratinocytes of chronic leg ulcers that is greater when the ulcers are nonhealing.     

Multiple sclerosis: myelin basic protein induced mRNA expression of proinflammatory cytokines in mononuclear cells is suppressed by interferon-β 1b in vitro

Beta-interferon (IFN-β) is a promising treatment in multiple sclerosis (MS), reducing the exacerbation rate and MRI lesion burden, as well as the disease progression in relapsing-remitting MS. IFN-β was originally defined by its antiviral effects, but the interest has recently been focused on its immunomodulatory properties. Myelin basic protein (MBP) is one of several autoantigens considered to be the target for autoaggressive immune responses, which eventually might lead to the development of MS. To study in-vitro effects of IFN-β1b on MBP induced cytokine expression, mRNA for the Th1 cytokines IFN-γ and TNF-α, the Th2 related IL-4 and IL-6, the cytolytic perforin and the immune response downregulating TGF-β was measured with in situ hybridization after culture of blood mononuclear cells (MNC) in the presence and absence of MBP. Numbers of cells expressing IFN-γ, TNF-α, perforin and IL-4 mRNA were significantly suppressed after culture with 10 U/ml IFN-β1b. No such effect was seen on MBP induced IL-6 or TGF-β mRNA expression. These observations suggest that one of the major effects of IFN-β1b is the induction of a shift in the cytokine mRNA profile towards a more immunosuppressive pattern. In parallel in vitro tests, the control substance dexametasone (40 μg/ml) reduced the numbers of cells expressing mRNA for all cytokines under study with the exception of TGF-β, to an extent equal to or even more pronounced than IFN-β1b.     

Elevated extracellular potassium is associated with a reduced extracellular space in rat neural lobe in vitro

Summary Increased neural activity of neurosecretory cells is accompanied by large increases in extracellular K⁺. The possibility that elevations of this ion might involve fluid redistribution and thus affect the size of the extracellular space and the relationship between pituicytes and axons in the rat neural lobe was explored using rapid freezing and freeze-substitution. Neural lobes were incubated for 15 min before freezing either in a normal medium or one containing a 10 mM increase in KCl (high KCl), a 10 mM increase in KCl balanced by an equimolar reduction in NaCl (high KCl-low NaCl), or only a 10 mM reduction in NaCl (low NaCl). A quantitative assessment of the region of good fixation was made to determine the relative fractions occupied by axons, pituicytes and the extracellular space near the neurohaemal contact zone. In addition, the percentage of basal lamina contacted by pituicytes and axons was calculated, as was the degree of enclosure of axons by pituicytes.In neural lobes incubated in normal medium, the extracellular space accounted for approximately 30% of the cross-sectional area of the neuropil and could be divided into two domains: an extended perivascular space (28–29% of total area); and a narrow (approximately 24 nm; approximately 1% of total) space between closely apposed neurosecretory processes or between these processes and pituicytes. Pituicytes occupied almost 60% of the basal lamina at the neurohaemal contact zone, while axons occupied approximately 20%. Neural lobes incubated in either the high KCl solution, or in the high KCl-low NaCl solution, exhibited a significantly reduced extracellular space, to about 20% of the total area, or a reduction from controls of about one-third. The reduction was complemented by an increased area occupied by axons plus pituicytes. In the high KCl group, the contribution of the narrow spaces (22–24 nm) between apposed processes to the total extracellular space was greatly increased. The group exposed to low NaCl showed high variability in the size of extracellular space, and was thus not significantly different from any other group. No changes in any group were observed in the enclosure of axons by pituicytes, or in the relative amounts of axon and pituicyte apposition to the basal lamina.The subsequent buffering of K⁺ and other ions during periods of increased neuronal activity may be affected by changes in the extracellular space, thereby influencing stimulus-secretion coupling. A shrinkage of the extracellular space and the relative increase in the narrow spaces between processes initiated by elevated K⁺ could also alter the diffusion properties of the neural lobe.     

305例老年死亡病例医院感染回顾性调查

本文结果表明,305例老年死亡病例医院感染的发病率为33.8％。感染最多部位为肺部(66.9％),其次为尿路感染(19.4％)。高龄患者,侵袭性操作、多种抗生素联合应用,激素疗法等是诱发医院感染的危险因素。58.8％的病原菌为革兰氏阴性杆菌,37.2％为真菌。31株病原菌药敏结果显示耐药率为33.3％。本文指出合理应用抗生素是预防医院感染的重要措施之一。     

以计算机为基础的教学(CBE)在护理领域的应用现状

随着计算机和网络技术的普及应用，以计算机为基础的教育(Computer Based Education，CBE)特别是多媒体课件的应用在护理教育中越来越受重视。然而，我国CBE在护理领域的应用尚处于起步阶段，也存在着一些缺陷和不足，有待于进一步完善。     

运动性肥大心肌活细胞胞浆游离Ca2+动态变化的激光共聚焦研究以及局部IGF-Ⅰ和AngⅡ的变化

目的:研究运动与心脏重塑过程中心肌胞浆游离Ca2 ([Ca2 ]c)动态变化的生物学机制.方法:采用激光扫描共聚焦显微技术(LSCM)对STDIn Ca2 荧光试剂负载的运动肥大心肌活细胞[Ca2 ]c动态变化进行研究,采用放射免疫测定运动小鼠心肌局部IGF-Ⅰ和AngⅡ含量.结果:运动肥大心肌[Ca2 ]c变化表现为基值稳态和峰值显著升高,达峰时间延长(P＜0.001).心肌局部IGF-Ⅰ和AngⅡ显著升高(P＜0.001).结论:运动性心肌肥大与[Ca2 ]c变化、机械信号、IGF-Ⅰ和AngⅡ关系密切,机械信号、IGF-Ⅰ和AngⅡ可能是引起[Ca2 ]c显著升高,增强心肌收缩能力的胞外刺激因素.     

第五届国际生殖内分泌学术会议纪要

秋日的北京凉爽宜人，2005年9月9～12日，由北京协和医院、国家人口计生委科学技术研究所主办，国际妇科内分泌协会和中国医学科学院协办，并由生殖医学杂志承办的第五届国际生殖内分泌学术会议在北京隆重举行。来自中国、美国、加拿大、英国、意大利、荷兰、比利时、芬兰、巴西、日本、菲律宾、     

N—酰化壳聚糖膜性能的研究

讨论了一系列N-酰化壳聚糖膜的抗张强度、透水性、VB_(12)的透过性、透氧性以及血液相容性。N-已酰化壳聚糖膜具有良好的血液相容性。在制膜过程中,加入分子量为1500的聚乙二醇为致孔剂,则可使N-己酰化壳聚糖膜的渗透性有较大提高。同时保持较好的血液相容性和强度。     

Release of Proinflammatory Cytokines During Pediatric Cardiopulmonary Bypass: Heparin-Bonded Versus Nonbonded Oxygenators

Background. Heparin bonding of the cardiopulmonary bypass (CPB) circuit may be associated with a reduced inflammatory response and improved clinical outcome. The relative contribution of a heparin-bonded oxygenator (ie, >80% of circuit surface area) to these effects was assessed in a group of pediatric patients.

Methods. Twenty-one pediatric patients undergoing CPB operations were assigned randomly to receive either a heparin-bonded oxygenator (group H, n = 11) or a nonbonded oxygenator (group C, n = 10) in otherwise nonbonded circuits. The two groups were similar in pathology, age, weight, CPB time, and cross-clamp time. Plasma levels of the cytokines tumor necrosis factor-, interleukin-6, and interleukin-8, as well as terminal complement complex, neutrophils, and elastase, were analyzed before, during, and after CPB.

Results. Significant levels of tumor necrosis factor- were not detected in either group. Plasma levels of all other markers increased during and after CPB compared with baseline. Plasma levels of interleukin-6 peaked in both groups 2 hours after the administration of protamine but remained significantly higher in group C 24 hours after operation. Plasma concentrations of interleukin-8 peaked at similar levels in both groups 30 minutes after protamine administration and returned to baseline thereafter. Levels of terminal complement complex and elastase peaked in both groups 30 minutes after protamine administration. Plasma levels of terminal complement complex were significantly higher at the end of CPB and after protamine administration in group C. Elastase levels were significantly higher 2 and 24 hours after CPB in group C. The ventilation time of patients in group H was significantly lower than that of patients in group C: 10 (range, 3 to 24) versus 22 (range, 7 to 24) hours, respectively (p < 0.01).

Conclusions. The present study confirms the proinflammatory nature of pediatric operations and demonstrates a lessened systemic inflammatory response with the use of heparin-bonded oxygenators. This is achieved without bonding of the entire circuit, which could have significant cost-benefit implications by negating the need for custom-built heparin-bonded circuitry.