The Influence of Age the BMI and All-Cause Mortality Association: A Meta-Analysis.

OBJECTIVES: To assess BMI range with the lowest mortality for those aged <65 years and those ≥65 years, utilising cohort studies that spanned the entire adult age range. DESIGN: A two-stage random effects meta-analysis of studies that reported mortality in cohorts both ≥65 years and <65 years. Setting / Participants: Community living adults aged ≥65 and <65 years. RESULTS: Eight studies were included with a total of 370 416 subjects (306 340 aged <65 years; 64 076 ≥65 years). In the older age group, mortality risk increased at BMIs lower than 22 (BMI range 21.0-21.9: hazard ratio (HR) (95% confidence interval (CI)): 1.05 (1.03, 1.07)), which was not seen in younger adults. In the younger group, mortality increased from BMI range 28.0-28.9 (HR (95% CI): 1.13 (1.00, 1.29)), but mortality did not tend to increase significantly in the older group at BMIs above 23. CONCLUSION: The recommended healthy weight range is appropriate for younger and middle aged adults but a higher BMI range should be recommended for older adults based on mortality.

Dacarbazine as single-agent therapy for relapsed lymphoma in dogs.

BACKGROUND: Multidrug resistance is the most common cause of treatment failure in dogs with multicentric lymphoma. 5-(3,3-Dimethyl-1-triazeno)-imidazole-4-carboxamide (DTIC) is an atypical alkylator used as standard treatment in human Hodgkin's lymphoma, and has been effective in combination treatment to treat resistant lymphoma in dogs. However, no data are available on the use of DTIC as a single agent in the treatment of relapsed canine lymphoma. HYPOTHESIS: Single-agent DTIC is effective and safe in treating dogs with lymphoma that relapsed or failed to respond to previous chemotherapy. ANIMALS: Forty client-owned dogs with relapsed lymphoma. METHODS: Dogs were eligible for the retrospective study if they had a histologically or cytologically confirmed diagnosis of lymphoma and had relapsed. Dogs received DTIC (800-1,000 mg/m(2) every 2-3 weeks as a 4-5-hour IV infusion) and were evaluated for response rate and duration. Hematologic and gastrointestinal toxicity was assessed. RESULTS: The overall response rate for dogs being treated with DTIC was 35% (14 dogs) with a median progression-free interval of 43 days. Thirteen dogs had a partial response and 1 dog had a complete response. Stable disease was achieved in 3 dogs. Mild gastrointestinal toxicity was reported in 3 dogs posttreatment. Thrombocytopenia was the principal toxicity observed 7-14 days after the treatment. Treatments were delayed because of thrombocytopenia. CONCLUSIONS: DTIC, when used alone, is effective in the treatment of dogs with relapsed lymphoma.

Chest X-rays in COPD screening: are they worthwhile?

The BTS/NICE COPD guideline recommends a chest X-ray at initial COPD evaluation; this is a grade D recommendation based on expert opinion. We have investigated which pathologies other than COPD are detected by chest X-ray and how they alter management. Dundee smokers aged 40 or over and receiving bronchodilators are assessed for COPD by their practice nurse and offered a chest X-ray if there is no record of a chest X-ray within the previous three years. We retrospectively analysed the chest X-ray reports and case records of these patients. The chest X-ray report was structured with 7 specific questions, most importantly "Are there any features of other disease likely to be causing dyspnoea?" and "Are there any features to suggest lung cancer?" Management of patients with chest X-ray findings suggesting other disease causing dyspnoea or lung cancer was assessed by questionnaire and case record study. Five hundred forty-six consecutive chest X-ray reports were analysed. Fourteen percent of all chest X-rays detected potentially treatable dyspnoea causing disease; where management following receipt of X-ray reports was audited, 84% were thought to help. Eleven lung cancers were detected, 3 had stage 1 disease. Considerable benign and malignant pathology is detected by chest X-ray performed at initial COPD assessment. Clinical management is changed in the majority with a potentially treatable abnormality. This evidence suggests that the NICE guideline to perform chest X-ray at initial COPD evaluation should be elevated from a grade D to grade C recommendation.

Reactivity of alkyl versus silyl peroxides. The consequences of 1, 2-silicon bridging on the epoxidation of alkenes with silyl hydroperoxides and bis(trialkylsilyl)peroxides.

The bond dissociation energies for a series of silyl peroxides have been calculated at the G2 and CBS-Q levels of theory. A comparison is made with the O-O BDE of the corresponding dialkyl peroxides, and the effect of the O-O bond strength on the activation barrier for oxygen atom transfer is discussed. The O-O bond dissociation enthalpies (DeltaH(298)) for bis (trimethylsilyl) peroxide (1) and trimethylsilyl hydroperoxide (2) are 54.8 and 53.1 kcal/mol, respectively at the G2 (MP2) and CBS-Q levels of theory. The O-O bond dissociation energies computed at G2 and G2(MP2) levels for bis(tert-butyl) peroxide and tert-butyl hydroperoxide are 45.2 and 48.3 kcal/mol, respectively. The barrier height for 1,2-methyl migration from silicon to oxygen in trimethylsilyl hydroperoxide is 47.9 kcal/mol (MP4//MP2/6-31G). The activation energy for the oxidation of trimethylamine to its N-oxide by bis(trimethylsilyl) peroxide is 28.2 kcal/mol (B3LYP/6-311+G(3df,2p)// B3LYP/6-31G(d)). 1,2-Silicon bridging in the transition state for oxygen atom transfer to a nucleophilic amine results in a significant reduction in the barrier height. The barrier for the epoxidation of E-2-butene with bis(dimethyl(trifluoromethyl))silyl peroxide is 25.8 kcal/mol; a reduction of 7.5 kcal/mol relative to epoxidation with 1. The activation energy calculated for the epoxidation of E-2-butene with F(3)SiOOSiF(3) is reduced to only 2.2 kcal/mol reflecting the inductive effect of the electronegative fluorine atoms.