Does support surface coefficient of friction influence postural dynamics and isometric force productions of the upper extremities performed by seated subjects?

The purpose of this study is to determine if increasing the potential risk of slipping on support surface materials decreases postural dynamics and task performance. Seated subjects were asked to exert maximum horizontal two-handed isometric pushes as quickly as possible on a dynamometric bar. Reaction forces exerted at seat (Rxs and Rzs) and footrest (Rxf and Rzf) were measured using force sensors. A dynamometric bar measured horizontal push force (Fx). Global adherence ratio (micro) was calculated. Three support surface materials, characterised by different coefficients of friction, were tested. The same surfaces were placed on the seat and the footrest during a series of pushes. It was shown that the different support surfaces significantly influence Fx, Rxs, Rzs, Rzf and micro maximum values obtained at the end of the push. Even when the instructions given to the subject are to produce a maximum push, the maximum horizontal force applied to the bar differs according to the support surface material. Dynamic postural adjustments are influenced by characteristics of slipperiness of support surfaces. The coefficient of friction contributes an essential element to the program of postural dynamics, which in turn modulates the task performance. During brief isometric pushes, seated subjects have the capacity to control the potential risk of slipping.     

Nucleotide sequence of the geminivirus chloris striate mosaic virus

The genome of chloris striate mosaic virus (CSMV) comprises a single circular DNA as determined by analyses on virion single-stranded (ss) DNA and virus-specific covalently closed circular (ccc) DNA isolated from infected plants. The nucleotide sequence of CSMV DNA was determined from cccDNA and the data were accommodated into one DNA circle of 2750 nucleotides. Comparison of the nucleotide sequence with those of maize streak virus (MSV), wheat dwarf virus (WDV), and digitaria streak virus (DSV) showed 49, 47, and 48% DNA homology, respectively. The sequence has four potential open reading frames for proteins of greater than 10,000 mol wt, two in the viral (+) sense and two in the complementary (-) sense. Three of these potential coding regions have homologous counterparts, by comparison of the amino acid sequences, among the open reading frames reported for MSV, WDV, and DSV. CSMV encapasidates primer molecules able to prime the synthesis in vitro of a complementary strand to virion DNA, initiating this reaction at one site on the genome. The CSMV primer comprising approximately 88 nucleotides was located within the smaller of two intergenic or noncoding regions.     

Surveillance of antibiotic resistance in invasive isolates of Neisseria meningitidis in Australia 1994-1999

A total of 1434 strains of Neisseria meningitidis isolated from cases of invasive meningococcal disease (IMD) in Australia between 1994 and 1999 were examined by standard methods for susceptibility to antibiotics used for treatment and prophylaxis. The proportion of isolates fully susceptible to penicillin decreased from 45% in 1994 to 26% in 1999 (P<0.001). All the other isolates were less sensitive to penicillin except for two meningococci with a penicillin MIC of 1 mg/l. The geometric mean penicillin MIC increased from 0.045 to 0.065 mg/l from 1994 to 1999. There was no significant difference in the geometric mean penicillin MICs of serogroup B and serogroup C meningococci. Penicillin susceptibility was significantly associated with a poorer outcome. Isolates from survivors of IMD had a higher geometric mean penicillin MIC (0.06 mg/l) than those from fatal cases (0.048 mg/l) (P< 0.001). This suggests that factors other than the decrease in susceptibility to penicillin observed were more relevant to outcome in IMD. All isolates were fully susceptible to ceftriaxone. Rifampicin resistance was infrequent (eight isolates in 6 years) and sporadic. A single isolate had decreased quinolone susceptibility. Despite the significant shift in susceptibility to penicillin recorded, this group of antibiotics remains a suitable treatment for IMD in Australia.     

人缺血脑组织中IP-10和IFN-γ的表达

目的：探讨趋化因子IP-10和细胞因子IFN-γ是否参与人缺血脑损伤过程。方法：将21例脑梗死死亡病例按发病持续时间分为〈7天、7～14天和15～21天3组，以非缺血侧半球做对照，用HE染色法观察炎性细胞浸润情况；通过免疫组织化学方法检测缺血半球脑组织与非缺血半球脑组织中趋化因子IP-10和细胞因子IFN-γ的表达。结果：在〈7天组和7～14天组中，缺血脑组织可见大量炎性细胞浸润。在〈7天组、7～14天组和15～2l天组中，趋化因子IP-10在缺血半球脑组织中的表达高于非缺血半球（分别是1．74倍增高，P〈0．01；1．41倍增高，P〈0．05和1．52倍增高，P〈0．01）。在对细胞因子IFN-γ的检测中发现〈7天和7～14天组中，IFN-γ在缺血半球脑组织中的表达高于非缺血半球（分别是1．65倍增高，P〈0．05和1．32倍增高，P〈0．05）；在15～21天组中，IFN-γ在缺血半球与非缺血半球中的表达没有显著差异（P〉0．05）。结论：在人缺血脑组织中观察到IP-10和IFN-γ的表达，提示IP-10和IFN-γ参与了炎症反应对脑组织的损伤过程。同时也提示IP-10可能参与后期对损伤脑组织的修复。     

A combination of genetic polymorphisms increases the risk of progressive disease in chronic hepatitis C

Background: There is increasing interest in the influence of host genetic factors on hepatic fibrosis, and whether genetic markers can reliably identify subjects at risk of developing severe disease. We hypothesised that hepatitis C virus (HCV) infected subjects with progressive fibrosis, classified using strict criteria based on histology at biopsy in addition to disease duration would be more likely to inherit several genetic polymorphisms associated with disease progression compared with subjects with a low rate of disease progression. Methods: We examined polymorphisms in eight genes that have been reported to have an association with hepatic fibrosis. Results: Associations between polymorphisms in six genes and more rapidly progressing fibrosis were observed, with individual adjusted odds ratios ranging from 2.1 to 4.5. The relationship between rapidly progressing fibrosis and possession of ⩾3, ⩾4, or ⩾5 progression associated alleles was determined and the adjusted odds ratios increased with increasing number of progression associated alleles (9.1, 15.5, and 24.1, respectively). Using logistic regression analysis, a predictive equation was developed and tested using a second cohort of patients with rapidly progressing fibrosis. The predictive equation correctly classified 80% of patients in this second cohort. Conclusions: This approach may allow determination of a genetic profile predictive of rapid disease progression in HCV and identify patients warranting more aggressive therapeutic management.     

Alternate therapy for traumatic pneumothorax in "pocket shooters"

Traumatic pneumothorax is a common complication of the IV drug abusers in Detroit who utilize the "pocket shot" (the central approach to the internal jugular vein). Fourteen patients who sustained a total of 16 pneumothoraces (two with bilateral collapse) and who underwent catheter aspiration of a simple pneumothorax (CASP) were studied prospectively. The sizes ranged from less than 10% to 100%. In addition, there was one tension pneumothorax and one pneumomediastinum. The 16 CASP procedures produced 13 successful lung expansions (82%). The remaining three were treated with tube thoracostomy and admission. Twelve of the 13 patients in whom the procedure was successful returned for followup, and all of these had 100% continued full expansion. CASP appears to be a safe, efficacious, and cost-effective treatment for the drug abuser with simple traumatic pneumothorax. With the current pressures of cost containment, this less-invasive approach with outpatient management should be studied as initial potential treatment for any simple pneumothorax.