Polycystic Ovarian Syndrome: the Next Cardiovascular Dilemma in Women?

All known risks for cardiovascular disease are increased in women with polycystic ovary syndrome, which features amenorrhea, hirsutism, and obesity. Epidemiologic studies in these patients and their families have revealed a familial predisposition not only to polycystic ovary syndrome, but also diabetes, hypertension, and cardiovascular disease. The heterogeneity of phenotypes (clinically and biochemically) leads to difficulty in achieving a precise diagnosis, defining a single underlying pathogenesis, and selecting a homogeneous population for much needed prospective studies. The authors believe that while insulin resistance plays and important role in some cases of polycystic ovarian syndrome, it is the overall milieu created by the co-existence of several cardiovascular risk factors in polycystic ovarian syndrome patients which could be an important target for preventative strategies and therapy.     

Novel mechanism of cellular DNA topoisomerase II inhibition by the pyranonaphthoquinone derivatives α-lapachone and β-lapachone

PURPOSE: The mechanisms of intracellular topoisomerase II inhibition by the pyranonaphthoquinone derivatives alpha-lapachone and beta-lapachone were studied. METHODS: Cell-based mechanistic studies were designed based on the in vitro mechanisms [17] and primarily involved the use of cultured KB (nasopharyngeal tumor cells) cells and the etoposide-resistant sub-line KB-7d. RESULTS: The KB-7d cells exhibited collateral sensitivity to alpha-lapachone; this supports the possibility of catalytic inhibition of topoisomerase II in the cells. Interestingly, both compounds induced an increase (two- to threefold) in reversible double-stranded DNA breaks in cell lines with a reduced expression of topoisomerase II. However, these drug-induced DNA breaks became irreversible at treatment times greater than 1 h. Studies showed that DNA breaks in KB-7d cells were not caused by endonucleases. Use of antioxidants abolished the appearance of cellular DNA breaks; this suggests involvement of the oxidation-reduction cycle of pyranonaphthoquinones in topoisomerase II inhibition; however, irreversible DNA breaks were not a result of drug-induced oxidative stress. CONCLUSIONS: On the basis of the findings, it is proposed that the compounds, on longer incubation with cells, induce abortive dissociation of topoisomerase II from the DNA, leading to an irreversible accumulation of high molecular weight DNA fragments. In addition to establishing topoisomerase II as an intracellular target of alpha-lapachone, the results suggest that both compounds can be classified as neither typical poisons nor as typical catalytic inhibitors of the enzyme. In summary, both compounds are members of a new inhibitor class, and alpha-lapachone, in particular, can be considered a potential lead for the development of drugs to treat multidrug-resistant cell lines with lower expression of topoisomerase II.     

印度亚拉文眼科模式

印度亚拉文医院是世界卫生组织合作单位,创造了“大规模、高质量、低成本”的眼科医疗模式,2005年,医院门诊量达163万多,手术超过22万例,其中白内障手术达16万多例,为世界之最。如何有效地借鉴印度亚拉文的模式为我所用,成为中国眼科界同仁日益热烈讨论的一个话题。本刊特邀印度亚拉文医院的主要负责人就该模式的特点撰文介绍。     

Impact of carotid tortuosity on outcome after endovascular thrombectomy

Neurological Sciences - Endovascular thrombectomy (EVT) is efficacious in patients with large vessel occlusion stroke (LVO). We explored whether internal carotid (ICA) tortuosity increases the...     

Invivo Comparative Evaluation of Tertiary Dentin Deposit to Three Different Luting Cements a Histopathological Study

The aim of the study is to evaluate histopathologically the amount of tertiary dentin deposit stimulated by three different luting cements. With the informed consent for fifteen patients crown preparation was done for maxillary and mandibular premolar teeth which were scheduled for orthodontic extraction. Copings were cemented with three different luting cements zinc oxide eugenol, glass ionomer and zinc polycarboxylate which were classified as Groups A, B and C respectively. The teeth were later extracted and histopathologically analysed for pulpodentinal reactions using a control study group. Statistically Tukey-HSD procedure was used to identify the significant group and one way ANNOVA was used to analyse the thickness of tertiary dentin among the study group. Tertiary dentin was seen in most of the specimens. When the three groups were compared zinc oxide eugenol helps in stimulation of tertiary dentin formation.     

Muscle Mass Index As a Predictor of Longevity in Older Adults

Objective

Obesity (as defined by body mass index) has not been associated consistently with higher mortality in older adults. However, total body mass includes fat and muscle, which have different metabolic effects. This study was designed to test the hypothesis that greater muscle mass in older adults is associated with lower all-cause mortality.

Methods

All-cause mortality was analyzed by the year 2004 in 3659 participants from the National Health and Nutrition Examination Survey III who were aged 55 years or more (65 years if women) at the time of the survey (1988-1994). Individuals who were underweight or died in the first 2 years of follow-up were excluded to remove frail elders from the sample. Skeletal muscle mass was measured using bioelectrical impedance, and muscle mass index was defined as muscle mass divided by height squared. Modified Poisson regression and proportional hazards regression were used to examine the relationship of muscle mass index with all-cause mortality risk and rate, respectively, adjusted for central obesity (waist hip ratio) and other significant covariates.

Results

In adjusted analyses, total mortality was significantly lower in the fourth quartile of muscle mass index compared with the first quartile: adjusted risk ratio 0.81 (95% confidence interval, 0.71-0.91) and adjusted hazard ratio 0.80 (95% confidence interval, 0.66-0.97).

Conclusions

This study demonstrates the survival predication ability of relative muscle mass and highlights the need to look beyond total body mass in assessing the health of older adults.