Neuroimaging in Pineal Tumors

BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.     

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.     

Is the outcome of in-vitro fertilization and embryo transfer treatment improved by spontaneous or surgical drainage of a hydrosalpinx?

A pilot study was designed to examine whether the outcome of embryo transfer in women with a hydrosalpinx might be improved by surgical drainage of the hydrosalpinx at the time of oocyte collection for in- vitro fertilization treatment. A comparative, controlled but retrospective analysis of the results was performed of all women with infective tubal damage aged <40 years old, who had ovulatory cycles, a normal uterus and a partner with normal spermatozoa. A standardized treatment regimen was used. A maximum of three embryos were transferred. Hydrosalpinx was defined by prior hysterosalpingography and/or laparoscopy with transcervical dye injection. A total of 237 embryo transfer cycles in women with hydrosalpinges (tubal distension not visible in 151, visible but not drained in 30 and drained in 56) were compared with 705 embryo transfer cycles in women with tubal disease but no hydrosalpinx. Results were analysed in the first three cycles but also separately in the first cycle to check for bias. Success rates were higher in the first cycle, but did not significantly influence overall differences. Implantation rates were significantly reduced overall in the hydrosalpinx group (8.0 versus 13.2% for controls; P < 0.001), being 8.3% (P < 0.01) in the subgroup without evident tubal distension and 7.5% (not significant) in the drained hydrosalpinx group. This study shows that tubal damage with distal occlusion is associated with a marked reduction in embryo implantation, even in the absence of obvious fluid distension. Surgical drainage of distended hydrosalpinges appears to offer no benefit.      

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).     

住院精神分裂症患者十年前后用药情况对比分析

目的对十年前后精神分裂症患者用药情况的变化进行调查分析.方法对十年前后两个五年段的各500份符合精神分裂症诊断标准的病历进行回顾性调查,并对各项指标进行对比分析.结果两组折算用药剂量经t检验差异无显著性(P>0.05);两组合并用药、合并抗胆碱药及疗效经χ2检验差异有显著性(P<0.01);十年后非典型抗精神病药物氯氮平在临床上的应用比例明显增大并上升为首位.结论十年前后两组抗精神病药的应用发生了明显变化,疗效好、副作用轻的非典型抗精神病药的应用比例明显增加.     

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.