Comparative Study of Leaf and Stem Bark Extracts of Parkia Biglobosa Against Enterobacteria

Hydroethanolic and aqueous extracts of leaf and stem bark of Parkia biglobosa (Jacq) Benth. (Mimosaceae) were tested against clinical isolates Escherichia coli, Salmonella typhi, Shigella dysenteriae and Enterococcus faecalis, and corresponding collection strains E. coli CIP 105 182, Salmonella enterica CIP 105 150, Shigella dysenteriae CIP 54-51 and Enterococcus faecalis CIP 103 907. Discs of Gentamicin, a broad spectrum antibiotic were used as positive controls. The results showed that all the extracts possess antimicrobial activities. A comparative study of the antibacterial activity of the leaves and that of the bark showed that for all the tested microorganisms, the hydroalcoholic extract of the bark is more active than the aqueous extract of the leaf. The hydroethanolic extract of the leaves is as effective as the aqueous extract of the stem bark prescribed by the traditional healer, suggesting it is possible to use leaves other than the roots and bark. The phytochemical screening showed that sterols and triterpenes, saponosides, tannins, reducing compounds, coumarins, anthocyanosides, flavonosides are present in both bark and leaf but in different concentrations.     

In vitro evaluation of human muscle satellite cell migration prior to fusion into myotubes

We developed a short-time assay to evaluate muscle satellite cell migration, based on the fact that during myogenic differentiation, myoblasts migrate preferentially towards high cellular density areas where myotubes would form. This assay consists of a computer-assisted count of cells within a randomly chosen field, performed every hour for eight hours, and compared with the cell number at the start time of the experiment. Nine primary myoblast cultures were tested in triplicate. The method relies on several requisites. (1) Negligible cell proliferation: cell division was nearly absent in 8h experiments. (2) Directional cell movement: a major flow of cells, either entering or exiting the fields, was constantly observed.Counter-flows, detected by visual counting, involved minor percentages of cells. (3) Constant migration rate: a linear increase in cell count variations over 8h and a very high degree of intra- assay homogeneity were observed. Individual primary cell culture characteristics (depending on characteristics of the different donors) were the sole factor with a significant impact on migration rate. Automatic cell counting conveniently assessed the inhibitory effect of GRGDTP, an inhibitor of integrin-mediated cell adhesion. The method described here is rapid, does not require heavy equipment, and allows studies under serum-free conditions required to test molecules interfering with cell migration, in the course of the in vitro myogenic process.     

MRI诊断肾肿瘤和术前分期的价值

目的:回顾性分析MRI对肾肿瘤的诊断价值并与病理和随访结果进行对比。方法:对46例疑有肾肿瘤的患者(男33例,女13例,平均年龄64.7岁)行MRI(1.5T)检查,扫描序列包括脂肪抑制TSET2WI、GRET1WI、脂肪抑制3DGRET1WI和增强扫描3DGREMR尿路成像。结果:本组46例中共发现142个肾脏病变,直径从<2cm到14cm×18cm。29例病变位于双侧,17例位于单侧。4例肿瘤为多中心性,其中3例为单肾分布、1例为双肾分布。根据MRI诊断标准,将病变分为囊性和实质性。22例患者可见囊性病变,其中19例为单纯囊性,3例为混合性。43个实体性肿瘤中35个(35/43)经组…     

Mutations and impaired function of LKB1 in familial and non-familial Peutz-Jeghers syndrome and a sporadic testicular cancer

Germline mutations in LKB1 have been reported to underlie familial Peutz-Jeghers syndrome (PJS) with intestinal hamartomatous polyps and an elevated risk of various neoplasms. To investigate the prevalence of LKB1 germline mutations in PJS more generally, we studied samples from 33 unrelated PJS patients including eight non-familial sporadic patients, 20 familial patients and five patients with unknown family history. Nineteen germline mutations were identified, 12 (60%) in familial and four (50%) in sporadic cases. LKB1 mutations were not detected in 14 (42%) patients, indicating that the existence of additional minor PJS loci cannot be excluded. LKB1 is predicted to encode a serine/threonine kinase. To demonstrate the putative Lkb1 kinase function and to study the consequences of LKB1 mutations in PJS and sporadic tumors, we have analyzed the kinase activity of wild-type and mutant Lkb1 proteins. Interestingly, while most of the small deletions or missense mutations resulted in loss-of-function alleles, one missense mutation (G163D) previously identified in a sporadic testicular tumor demonstrated severely impaired but detectable kinase activity.      

In-house development of test equipment for quality control and training. Case study: a prototype ECG simulator-tester

The support services for biomedical technology address a variety of technical and administrative issues, concerning the safe and efficient operation of medical equipment over the period of its intended use and the training of hospital personnel in issues concerning safety and quality. Clinical Engineering Departments undertake the responsibility of developing and operating training programs in medical equipment utilisation apart from the traditional role of training and supervising technicians involved in testing, calibration and preventive/corrective maintenance of electromedical equipment. In view of the above, the Institute of Biomedical Technology and the Centre of Biomedical Engineering collaborated for the design and development of a prototype digital ECG and arrhythmia simulator. In the absence of internationally accepted inspection protocols for ECG simulators, the verification phase of the project involved mainly the inspection of the device's conformity to its initial technical specifications. The results demonstrated that this tester, due to simplicity in construction and easiness of use could be a practical, reliable and economical solution for electrocardiograph and ECG monitor testing and waveform recognition training.     

Possible Evidence for a Variant of Myasthenia Gravis Based on HLA and Acetylcholine Receptor Antibody in Chinese Patients

SUMMARY A comprehensive study of 194 Chinese patients with myastheniagravis in Hong Kong has shown district differences from thepatterns of disease seen in Caucasians. Restricted ocular myastheniais the predominant disease type in patients presenting in thefirst two decades of life and is associated with absence orlow titres of acetylcholine receptor antibody. Predispositionto this type of disease is strongly associated with HLA-DRw9.Generalized myasthenia gravis occurs predominantly in patientspresenting after the age of 20 years and is accompanied by hightitres of acetylcholine receptor antibody but is less stronglyassociated with HLA-DRw9. It is suggested that myasthenia gravisoccurring within the first two decades of life and characterizedby affected ocular muscles and absence or low titre of acetycholinereceptor antibody is a genetically determined variant of thedisease which occurs commonly in Orientals.     

Automatic detection of atrial fibrillation and flutter by wave rectification method.

Rapid detection of atrial flutter or fibrillation is needed in intensive care or home ECG monitoring with alarm generation, and in portable monitors with warningfunction, etc. Detection and assessment of these atrial abnormalities is necessary in computerized morphological analysis as well, to decide whether parameter measurements should be rejected, restricted to QRS and/or T wave only, or limited to those leads where atrial flutter orfibrillation waves are less expressed. A method for the detection and measurement of atrial flutter and fibrillation in the T-P segments of the ECG is proposed. An atrial flutter/ fibrillation parameter (AFF) is defined as the mean value of the differentiated filtered and rectified signal in these segments. The AFF has been measured in 329 patients from an annotated atrial flutter-fibrillation database. A threshold of AFF=0.35% with respect to the maximum signal excursion was chosen by a heuristic algorithm, to separate patients with atrial arrhythmia. The accuracy of the method was 91.8 %. The positive and negative detection errors of the AFF classification are discussed.     

一叶萩生物碱类成分研究

目的对一叶萩的生物碱类成分进行研究。方法采用各种色谱技术对一叶萩的总生物碱部位进行分离,应用理化常数和波谱技术(NMR、MS等)鉴定化合物的结构。结果自一叶萩枝叶的总碱部位中分离得到2个新的生物碱类化合物,分别命名为叶下珠碱B(phyllanthidine B,4α-methoxy-phyllanthidine,Ⅰ)和一叶萩醇D(securi-nolD,14β-hydroxyviroallosecurinine,Ⅱ)。结论化合物和均为新化合物。