腹腔间室综合征:当前存在的问题和新的治疗策略

腹腔间室综合征(ACS)是一种处理起来十分棘手的疾病,ACS对病人的血管、呼吸、肾脏及神经等系统的功能均有不良影响.     

Evaluation of tamoxifen and alpha-hydroxytamoxifen 32P-post-labelled DNA adducts by the development of a novel automated on-line solid-phase extraction HPLC method

A novel HPLC system has been developed that has allowed the separation of tamoxifen DNA adducts formed in the livers of rats and mice treated with this drug. At least 13 different peaks have been separated from 32P-post-labelled DNA, with two major peaks jointly accounting for >60% of the total adducts formed by tamoxifen in the livers of treated rats and mice. This is a great improvement on the resolution obtained by thin layer chromatography, which separates the adducts into one main product consisting of a group of major adduct spots eluting together, plus several other minor spots. Identification of the nature of some of the peaks has been investigated. Comparisons of the products formed when alpha-acetoxytamoxifen is reacted with DNA in vitro with 32P-post- labelled liver DNA adducts from rats treated with tamoxifen or alpha- hydroxytamoxifen in vivo, appear to confirm that a major route of activation of tamoxifen in vivo is via alpha-hydroxylation. The resolving power of this HPLC system has further extended this result to show that six of the peaks, including the two major peaks, are formed by the reaction of an activated alpha-hydroxytamoxifen with DNA. Activation of 4-hydroxytamoxifen by the peroxidase/H2O2 system in vitro gives a more polar DNA adduct seen only at trace levels in liver DNA from tamoxifen-treated rats and mice.      

Tissue osmolality in intestinal villi of four mammals in vivo and in vitro

Using a freezing point depression method osmolality in the intestinal tissue of four mammals (gerbils, guinea-pigs, rabbits and rats) was estimated in vivo, during fluid transport from an isotonic electrolyte-glucose solution. Net fluid transport was also measured. In gerbils, guinea-pigs and rabbits tissue osmolality was also estimated during in vitro conditions. A marked hyperosmolality was observed in vivo in the upper parts of the villi of all four mammals studied. The tissue osmolality was significantly higher than that seen in the same species during in vitro conditions. A villus hyperosmolality was observed also in species which exhibited a net fluid secretion (guinea-pig, rabbit ileum), indicating that the fluid secretion emanated from the intestinal crypts. Based on the results of the present experiments and on observations made in earlier experiments performed on the cat, it is proposed that the villus hyperosmolality is created by a countercurrent multiplier present in the intestinal villus. The hyperosmolar compartment in the villus tissue creates the force that drives fluid from lumen to tissue.     

Inhibition of release of inflammatory mediators in primary and cultured cells by a Chinese herbal medicine formula for allergic rhinitis

Background  

We demonstrated that a Chinese herbal formula, which we refer to as RCM-101, developed from a traditional Chinese medicine formula, reduced nasal and non-nasal symptoms of seasonal allergic rhinitis (SAR). The present study in primary and cultured cells was undertaken to investigate the effects of RCM-101 on the production/release of inflammatory mediators known to be involved in SAR.     

Antimicrobial, Wound Healing and Antioxidant Activities of Anthocephalus Cadamba

Anthocephalus cadamba (Roxb.) Miq. Syn A. chinensis (Lamk) A. Rich (Rubiaceae) is ethnomedicinally widely used in the form of paste by tribe in western Ghats for treating skin diseases. In this context, antimicrobial potential of A. cadamba against a wide range of microorganisms was studied. To validate the ethnotherapeutic claims of the plant in skin diseases, wound healing activity was studied, besides antioxidant activity to understand the mechanism of wound healing. The alchoholic and aqueous extract of this plant showed significant antibacterial and antifungal activity against almost all the organisms: Micrococcus luteus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and four fungi Candida albicans, Trichophyton rubrum—dermatophyte fungi, Aspergillus niger, Aspergillus flavus and Aspergillus nidulans—systemic fungi, with especially good activity against the dermatophyte (Trichophyton rubrum) and some infectious bacteria (Escherichia coli, Proteus mirabilis and Staphylococcus aureus) with an MIC of 2.5 µg/disc. The results show that A. cadamba extract has potent wound healing capacity as shown from the wound contraction and increased tensile strength. The results also indicated that A. cadamba extract possesses potent antioxidant activity by inhibiting lipid peroxidation and increase in the superoxide dismutase (SOD) and catalase activity.     

Anti B cell targeted immunotherapy for treatment of refractory autoimmune haemolytic anaemia in a young infant

We report the case of an 8 week old infant with fulminant autoimmune haemolytic anaemia refractory to conventional immunomodulating treatment. Massive haemolysis resulted in cardiac decompensation and acute renal failure which necessitated mechanical ventilation and peritoneal dialysis. Rituximab, a chimeric anti-CD20 monoclonal antibody, halted progression of the haemolytic process, but the patient died of acute viral pneumonia and disseminated fungal infection. Earlier introduction of rituximab might have prevented the renal complications. Paediatricians should be aware of this useful therapeutic tool for treatment of refractory autoimmune haemolytic anaemia and balance its use against the risk of potential life threatening infection.     

EXPLAINED VARIATION FOR LOGISTIC REGRESSION

Different measures of the proportion of variation in a dependent variable explained by covariates are reported by different standard programs for logistic regression. We review twelve measures that have been suggested or might be useful to measure explained variation in logistic regression models. The definitions and properties of these measures are discussed and their performance is compared in an empirical study. Two of the measures (squared Pearson correlation between the binary outcome and the predictor, and the proportional reduction of squared Pearson residuals by the use of covariates) give almost identical results, agree very well with the multiple R² of the general linear model, have an intuitively clear interpretation and perform satisfactorily in our study. For all measures the explained variation for the given sample and also the one expected in future samples can be obtained easily. For small samples an adjustment analogous to R²_adj in the general linear model is suggested. We discuss some aspects of application and recommend the routine use of a suitable measure of explained variation for logistic models.     

实证医学与中医药研究和开发

临床疗效是衡量一切防治措施价值的最高准则,也是决定一个医疗卫生体系效益的最基本因素。实证医学的核心就是任何有关疾病防治的整体策略和具体措施的制定都应基于现有最严谨的关于其临床疗效的科学证据之一。使用无效甚至有害的防治措施在伦理上是不能接受的,更是对人类宝贵医疗资源的浪费。因此,中医药研究和开发应从临床疗效的验证开始。机理的研究、有效成份的探索和剂型的改进是重要的,但应以证实临床有效为前提。本文从 ４个方面进行了论证： １、一个防治措施若没有防治作用,就没有其相关的作用机理可被发现,也没有其相关的有效成份可被探索,更没有改进剂型的必要。２、中医药临床疗效评价,为从中医药中开发新药提供一个经济的、快捷的途径。因为它节省了用于无临床疗效的药物的临床前研究所需要的大量资源。同时也大大缩短了一个新药从开发到临床使用的时间。３、中医药临床疗效评价具有巨大的经济效益。临床上无效的防治措施被淘汰,而有效的被进一步推广。从而一个医疗体系会因减少使用无效的防治措施而提高效益。４、对中医药临床疗效的评价也是对其理论体系在实践上的检验。     

The effect of myelination on perimetry and retinal nerve fibre analysis

Background: Myelinatecl retinal nerve fibres around the optic nerve head can lead to an enlargement of blind spot with kinetic perimetry. Presumably extensive myelination will also decrease the visual sensitivity with static perimetry. This study reports the effect of myelination on static perimetry in several patients. Scanning laser polarimetry can measure the retinal nerve fibre layer thickness around the optic nerve head in vivo. This technique was applied at the myelination to investigate its effect on retinal nerve fibre layer thickness determination. Methods: Four eyes of three subjects with myelination around the optic nerve head were tested with Bjerrum screen at one metre to measure the blind spot size. They were followed by Humphrey Visual Field Analyser with a custom pattern to quantify the threshold level at the blind spot region. A GDx Nerve Fiber Analyser was used to measure the retinal nerve fibre layer thickness around the optic nerve head. Results: All the patients demonstrated an enlargement of the blind spot, with different extents, corresponding to the area of myelination. Threshold testing revealed a depression in the myelinated regions. The results for retinal nerve fibre layer were not conclusive with two eyes demonstrating thickening and two eyes showing no effect from myelination. Conclusions: A static field test with a modern visual field analyser may help to quantify the effect of myelination on visual sensitivity. More studies on the effect of myelination on retinal nerve fibre layer thickness measurement are suggested with more subjects involved.