拉萨地区冠心病与幽门螺杆菌感染相关性研究

目的探讨西藏拉萨地区幽门螺杆菌（Helicobacter pyloric，Hp）感染与冠心病及多种危险因素的关系。为该地区冠心病的防治提供依据。方法分为冠心病组46例和非冠心病组51例，应用检测血抗HpIgG及-C-尿素呼气试验方法检测Hp感染情况，并分别测定各组血脂、血糖、餐后2h血糖、C反应蛋白、纤维蛋白原、白细胞总数。结果冠心病组患者血清抗HpIgG阳性率为50．0％（23／46），明显高于非冠心病组的23．5％（12／51），P〈0．05；冠心病患者Hp现症感染率为54．3％（25／46），明显高于非冠心病组的31．3％（27／51），P〈0．05；冠心病组Hp感染患者血脂、空腹及餐后2h血糖、C反应蛋白、纤维蛋白原较非感染患者明显升高（P〈0．05）。结论Hp感染与冠心病相关，可能是拉萨地区冠心病发病的独立危险因素。     

Three-year assessment of methicillin-resistant Staphylococcus aureus clones in Latin America from 1996 to 1998

Four hundred ninety-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from 1996 to 1998 from 22 hospitals in five countries of Latin America-Argentina, Brazil, Chile, Uruguay and Mexico-were examined for antimicrobial susceptibility and clonal type in order to define the endemic clones in those hospitals. The hybridization of ClaI restriction digests with the mecA- and Tn554-specific DNA probes combined with pulsed-field gel electrophoresis of chromosomal SmaI digests (ClaI-mecA::ClaI-Tn554::PFGE clonal types) documented not only the predominance and persistence of the Brazilian clone (XI::B::B) in Brazil (97%) and Argentina (86%) but also its massive dissemination to Uruguay (100%). Moreover, a close relative of the Brazilian clone (XI::kappa::B) was highly represented in Chile (53%) together with a novel clone (47%) (II::E'::F) resistant to pencillin, oxacillin, ciprofloxacin, chloramphenicol, clindamycin, erythromycin, and gentamicin. A unique clonal type (I::NH::M) was detected in Mexico among pediatric isolates and was resistant to penicillin, oxacillin, and gentamicin only. This study clearly documented the very large capacity for geographic expansion and the persistence of the Brazilian clone, contributing not only to the increasing uniformity of the MRSA in South America but worldwide as well.     

Serotypes of carriage and invasive isolates of Streptococcus pneumoniae in Brazilian children in the era of pneumococcal vaccines

Nasopharyngeal carriage of Streptococcus pneumoniae is a key factor in the development of invasive disease and the spread of resistant strains within the community. A single nasopharyngeal swab was obtained from 648 unvaccinated children aged <5 years, either healthy or with acute respiratory tract infection or meningitis, during the winters of 2000 and 2001. The overall pneumococcal carriage rate was 35.8% (95% CI 32.1-39.6). The pneumococcal serotypes found most frequently in the nasopharynx were 14, 6B, 6A, 19F, 10A, 23F and 18C, which included five of the seven serotypes in the currently licensed seven-valent conjugate vaccine (PCV7); serotypes 4 and 9V were less common. Serotypes 1 and 5 were isolated rarely from the nasopharynx. A comparison of 222 nasopharyngeal isolates with 125 invasive isolates, matched for age and time to the carrier isolates, showed a similar prevalence of penicillin non-susceptible pneumococci (PNSp) (19.8% and 19.2%, respectively). PNSp serotypes were similar (6B, 14, 19F, 19 A, 23B and 23F) for carriage and invasive disease isolates. The coverage of PCV7 for carriage isolates (52.2%) and invasive isolates (62.4%) did not differ significantly (p 0.06); similarly, there was no significant difference in PCV7 coverage for carriage isolates (34.5%) and invasive isolates (28.2%) of PNSp. These data suggest that PCV7 has the potential to reduce pneumococcal carriage and the number of carriers of PNSp belonging to vaccine serotypes.     

Synthesis and Characterization of Hyperbranched Polyethylenes Made with Nickel‐α‐Diimine Catalysts

The polymerization of ethylene in the presence of 1,4‐bis(2,6‐diisopropylphenyl)acenaphthenediiminenickel(II) dichloride ( 1 ) and methylaluminoxane (MAO) gives hyperbranched polyethylene (HBPE) in appropriate reaction conditions. The system 1 /MAO is active in solvents like toluene or hexane at temperatures as high as 80 °C and ethylene pressures ranging from 1 to 15 atm. The polyethylenes obtained show high molecular weights (up to 467 kg · mol^?1) and more than 218 branches per 1 000 backbone carbon atoms, qualifying these materials as hyperbranched. Dynamic‐mechanical thermal analysis (DMTA) of these materials shows high β‐transitions, directly related to the branch content of these polyethylenes.

DMTA analysis of polyethylenes obtained with 1 /MAO at 0, 30, and 50 °C (corresponding to entries 1, 2 and 3).     

Effects of ACE inhibition in normotensive patients with chronic glomerular disease and normal renal function

A double-blind, placebo-controlled study was carried out to assess the effects of a three-month treatment with a new ACE inhibitor, Benazepril (BNZ), on systemic and renal hemodynamics, and urine protein excretion, in 20 patients with chronic glomerulonephritis, normal blood pressure (130/83 +/- 16/10 mm Hg), and normal renal function (creatine clearance 106 +/- 25 ml/min). Treatments with placebo or BNZ were assigned randomly. A wide range of proteinuria lowering effect was observed in overall population (from 1 to 84%, average 34%). Following the arbitrary level of a 30% reduction, two well-matched subgroups (10 patients for each one) were obtained: "good responders" (average decrease 51%), and "poor responders" (average decrease 17%). The main distinctive feature between the two groups was a higher plasma renin activity level in good than in poor responders. A positive correlation between the fall in proteinuria and blood pressure was found. Although the decrease in blood pressure seems to represent the major factor in determining the reduction in proteinuria, a multiple correlation analysis showed that the most prominent role (71%) was attributable to the combined decrease in blood pressure and filtration fraction, and then also to the efferent arteriole dilatation. Our conclusion is that ACE inhibitors are capable of also reducing proteinuria in patients with renal disease with normal blood pressure, the effect being more pronounced in those exhibiting humoral, systemic and renal hemodynamic patterns, indicating a greater activity of circulating and renal renin angiotensin system.     

The epidemiology of endometrial cancer in young women

A case-control study was conducted in Los Angeles County, California, of 127 endometrial cancer cases aged 45 years or less at diagnosis, to investigate the role of fertility, obesity and exogenous oestrogens in the development of the disease in young women. Use of sequential oral contraceptive (SOCs) or oestrogen replacement therapy (ERT) for greater than or equal to 2 years was strongly associated with increased risk of endometrial cancer. After excluding these cases, since the SOC or ERT use was probably the cause of their disease, we were left with 110 case-control pairs for further study. Among these remaining case-control pairs increasing parity was strongly associated with decreased risk (relative risk of 0.12 for women of parity 3 compared to nulliparous women, P less than 0.001). Current weight was associated with increased risk (relative risk of 17.7 for women weighing greater than or equal to 190 lbs compared to women weighing less than 130 lbs, P less than 0.001). Combination oral contraceptive (COC) use was associated with a decreased risk, which decreased with duration of COC use (relative risk of approximately 0.28 at 5 years of use, P less than 0.001), but the estimate of the protective effect was reduced and became statistically non-significant when allowance was made for weight and parity. The protective effect of COC use was only clearly evident in women who had less than 3 live-births and weighed less than 170 lbs. These results provide further support for the "unopposed" oestrogen hypothesis of the aetiology of endometrial cancer.     

Comparative mouse skin tumorigenicity and induction of Ha-ras mutations by bay region diol epoxides of 5-methylchrysene and 5,6- dimethylchrysene

We compared the tumor-initiating activities toward mouse skin of two structurally related polycyclic aromatic hydrocarbon diol epoxides: racemic anti-1,2,3,4-tetrahydro-5,6-dimethylchrysene-1,2-diol-3,4- epoxide (5,6-diMeCDE) and racemic anti-1,2,3,4-tetrahydro-5- methylchrysene-1,2-diol-3,4-epoxide (5-MeCDE). Tumors induced by these diol epoxides were analysed for mutations in the Ha-ras gene. 5,6- diMeCDE is derived from the non-planar parent compound 5,6- dimethylchrysene, and reacts to approximately equal extents with dA and dG in DNA, whereas 5-MeCDE is derived from a nearly planar parent compound, 5-methylchrysene, and reacts mainly with dG in DNA. 5,6- diMeCDE, at initiating doses of 33, 100 or 400 nmol per mouse, induced 1.2, 2.2 and 6.2 skin tumors per mouse, respectively. It was significantly less tumorigenic than 5-MeCDE which induced 3.1, 7.5 and 9.1 skin tumors per mouse at the same doses. Tumors induced by 5,6- diMeCDE had a large number of CAA-->CTA mutations in codon 61 of the Ha- ras gene: 50, 55 and 75% of the tumors analysed had this mutation at the 33, 100 and 400 nmol doses. No mutations were found in codons 12 and 13 in the tumors induced by 5,6-diMeCDE. In contrast, CAA-->CTA mutations in codon 61 were rarely seen in tumors induced by 5-MeCDE. At the highest dose of 5-MeCDE, 20% of the tumors analysed had mutations at G of codons 12 and 13. The results of this comparative study support the hypothesis that mutations in the Ha-ras gene in mouse skin tumors induced by PAH diol epoxides occur as a result of their direct reaction with the gene. However, pathways other than the commonly observed Ha- ras codon 61 mutations are clearly important in mouse skin tumorigenesis by these diol epoxides.      

Médecin traitant et médecin correspondant: mécanisme et missions

Résumé: La loi du 13 août 2004 relative à l’assurance maladie a instauré un système de coordination des soins reposant sur une centralisation de la prise en charge par un médecin traitant choisi par le patient.Dans ce système en vigueur depuis le 1^er juillet 2005, le médecin traitant assure la coordination des soins et les soins de premier recours. Les médecins intervenant en concertation avec le médecin traitant, les médecins correspondants, assurent quant à eux le second recours au système de soins, et notamment les soins les plus spécialisés.Les patients qui ne désignent pas un médecin traitant seront financièrement pénalisés.D’un commun accord avec son patient, tout cancérologue peut exercer la fonction de médecin traitant.