Hamiltonian Quantization of Effective Lagrangians with Massive Vector Fields

Effective Lagrangians containing arbitrary interactions of massive vector fields are quantized within the Hamiltonian path integral formalism. It is proven that correct Hamiltonian quantization of these models yields the same result as naive Lagrangian quantization (Matthews's theorem). This theorem holds for models without gauge freedom as well as for (linearly or nonlinearly realized) spontaneously broken gauge theories. The Stueckelberg formalism, a procedure to rewrite effective Lagrangians in a gauge invariant way, is reformulated within the Hamiltonian formalism as a transition from a second class constrained theory to an equivalent first class constrained theory. The relations between linearly and nonlinearly realized spontaneously broken gauge theories are discussed. The quartically divergent Higgs self interaction is derived from the Hamiltonian path integral.Comment: 16 pages LaTeX, BI-TP 93/1

Are C-reactive protein and homocysteine cardiovascular risk factors in obese children and adolescents?

Background: Several prospective epidemiological studies have demonstrated that high-sensitivity C-reactive protein (hsCRP) and plasma homocysteine (hcy) are predictors of future coronary events among healthy men and women. The aim of the present study was therefore to investigate a possible relationship between hsCRP, hcy levels and body mass index (BMI), relative weight (RW), serum leptin levels, and cardiovascular risk factors in obese children and adolescents. Methods: The study involved 28 obese children and adolescents (13 girls, 15 boys; BMI>95‰ for age and sex), 4.5-15 years of age (mean 10.7 ± 0.6 years), who attended hospital for a basic obesity check-up. The association between hsCRP, hcy levels and BMI, RW, serum leptin levels, and cardiovascular risk factors such as blood pressure (BP), lipid profile, serum fasting insulin levels, and insulin resistance indexes, was investigated. Results: Serum hsCRP level was positively correlated with BMI (r = 0.512, P < 0.01), RW (r = 0.438, P < 0.05), systolic and diastolic BP (r = 0.498, P < 0.01), serum leptin levels (r = 0.457, P < 0.05), but not with serum lipid, glucose, fasting insulin, plasma hcy levels or insulin resistance indexes. For hcy level, in contrast, no correlation was found with BMI, RW, systolic and diastolic BP, serum lipid levels, leptin, hsCRP, glucose, fasting insulin levels, or insulin resistance indexes. Conclusions: hsCRP is correlated with BMI, RW, BP and leptin, which are risk factors for coronary heart disease, which supports the relationship between obesity, inflammation and atherosclerosis. hsCRP in childhood obesity might be a useful index to predict possible atherosclerotic events. © 2008 Japan Pediatric Society

A role of leptin in psoriasis?

Aim: Although there is evidence of a positive association between psoriasis and body mass index (BMI) and leptin is known to play a part in the regulation of the immune system, the relationship between psoriasis and leptin is still not well known. The aim of this study was to evaluate the possible relation between leptin and psoriasis. Materials and Methods: Serum leptin concentrations and BMI in 20 patients with psoriasis were compared to 20 age- and sex-matched healthy volunteers. Results: There was no difference between serum leptin levels of psoriatic patients (32.3 ± 24.9 ng/ml) and controls (36.8 ± 28.2 ng/ml). Leptin levels of both psoriatic and healthy volunteers showed positive correlations with BMI. Serum leptin levels in the patient group did not correlate with psoriasis area severity index (PASI) score or duration of psoriasis. Conclusions: In the setting of this study, our results did not support any possible relation between serum leptin levels and psoriasis. © TÜBİTAK