Thermogenesis in brown adipose tissue with age: Post-receptor activation by forskolin

₃-Adrenergic-stimulated thermogenesis in brown adipose tissue (BAT) is diminished with age. ₃-Adrenergic receptors are positively coupled to adenylyl cyclase in BAT. To determine whether thermogenesis, in response to direct activation of adenylyl cyclase, is also impaired with age, we examined whole body oxygen consumption, mitochondrial guanosine diphosphate (GDP) binding and BAT mitochondrial uncoupling protein (UPC) mRNA levels in 4- and 24-month-old F-344 rats following forskolin administration. We also examined the forskolin-induced change in body temperature in 4-month-old rats. In some instances, the results were compared with administration of the specific ₃-adrenergic agonist, CGP-12177. Forskolin (3.5 mg/kg) increased oxygen consumption but decreased body temperature. In subsequent experiments the BAT was unilaterally denervated. In these rats, the forskolin-(1.8 mg/kg) stimulated increase in oxygen consumption was similar in young and old rats. Forskolin increased GDP binding and UCP mRNA levels in both the denervated and innervated BAT pads. The increases were equal or greater in the BAT from senescent rats. These findings, coupled with our previous report of an impaired CGP-12177-stimulated increase in GDP binding in senescent rats, suggests ₃-adrenergic-stimulated, but not post-receptor-stimulated, thermogenesis is diminished with age.     

Detecting temporal expressions in medical narratives

BackgroundClinical practice and epidemiological information aggregation require knowing when, how long, and in what sequence medically relevant events occur. The Temporal Awareness and Reasoning Systems for Question Interpretation (TARSQI) Toolkit (TTK) is a complete, open source software package for the temporal ordering of events within narrative text documents. TTK was developed on newspaper articles. We extended TTK to support medical notes using veterans’ affairs (VA) clinical notes and compared it to TTK.MethodsWe used a development set consisting of 200 VA clinical notes to modify and append rules to TTK's time tagger, creating Med-TTK. We then evaluated the performances of TTK and Med-TTK on an independent random selection of 100 clinical notes. Evaluation tasks were to identify and classify time-referring expressions as one of four temporal classes (DATE, TIME, DURATION, and SET). The reference standard for this test set was generated by dual human manual review with disagreements resolved by a third reviewer. Outcome measures included recall and precision for each class, and inter-rater agreement scores.ResultsThere were 3146 temporal expressions in the reference standard. TTK identified 1595 temporal expressions. Recall was 0.15 (95% confidence interval [CI] 0.12–0.15) and precision was 0.27 (95% CI 0.25–0.29) for TTK. Med-TTK identified 3174 expressions. Recall was 0.86 (95% CI 0.84–0.87) and precision was 0.85 (95% CI 0.84–0.86) for Med-TTK.ConclusionThe algorithms for identifying and classifying temporal expressions in medical narratives developed within Med-TTK significantly improved performance compared to TTK. Natural language processing applications such as Med-TTK provide a foundation for meaningful longitudinal mapping of patient history events among electronic health records. The tool can be accessed at the following site: http://code.google.com/p/med-ttk/.     

Israeli and British women's wellbeing and eating behaviours in pregnancy and postpartum

Objectives: The study had two main objectives: (a) track changes in self-esteem, eating behaviours and body satisfaction from early pregnancy to 24 months postpartum and (b) to compare changes by context (Israel vs. UK) and maternal body mass index (BMI).

Background: High maternal BMI is associated with negative body image and restrained eating, which are experienced differently across cultures.

Methods: 156 pregnant women were recruited from Israel and the UK. Seventy-three women were followed up every six months from early postpartum and until 24 months following birth. Women completed questionnaires assessing self-esteem (RSEQ), body image (BIS/BIDQ) and eating behaviours (DEBQ) and self-reported weights and heights so that BMI could be calculated.

Results: Women with higher BMI had higher levels of self-esteem and were less satisfied with their body. Healthy-weight women were more likely to lose all of their retained pregnancy weight compared to overweight and obese women. Self-esteem, body image and eating behaviours remained stable from pregnancy until 24 months postpartum. No significant differences were found for any measure by context.

Conclusion: BMI was the strongest predictor of self-esteem and body dissatisfaction and a higher BMI predicted less weight loss postpartum.