Birth weight, early life weight gain and age at menarche: a systematic review of longitudinal studies.

BACKGROUND AND OBJECTIVE: Adiposity in pre- and postnatal life may influence menarcheal age. Existing evidence is primarily cross-sectional, failing to address temporality, for which the role of adiposity in early life remains unclear. The current study sought to systematically review longitudinal studies evaluating the associations between birth weight and infant/childhood weight status/weight gain in relation to menarcheal age. METHODS: PubMed, EMBASE, Web of Science, Global Health (Ovid) and CINAHL were systematically searched. Selected studies were limited to English-language articles presenting multi-variable analyses. Seventeen studies reporting risk estimates for birth weight (n = 3), infant/childhood weight gain/weight status (n = 4) or both (n = 10), in relation to menarcheal age were included. RESULTS: Lower vs. higher birth weight was associated with earlier menarche in nine studies and later menarche in one study, while three studies reported a null association. Greater BMI or weight gain over time and greater childhood weight were significantly associated with earlier menarche in nine of nine and six of seven studies, respectively. CONCLUSIONS: Studies suggested that lower birth weight and higher body weight and weight gain in infancy and childhood may increase the risk of early menarche. The pre- and postnatal period may thus be an opportune time for weight control interventions to prevent early menarche, and its subsequent consequences.

Ecological succession of the microbial communities of an air-conditioning cooling coil in the tropics.

Air-conditioning systems harbor microorganisms, potentially spreading them to indoor environments. While air and surfaces in air-conditioning systems are periodically sampled as potential sources of indoor microbes, little is known about the dynamics of cooling coil-associated communities and their effect on the downstream airflow. Here, we conducted a 4-week time series sampling to characterize the succession of an air-conditioning duct and cooling coil after cleaning. Using an universal primer pair targeting hypervariable regions of the 16S/18S ribosomal RNA, we observed a community succession for the condensed water, with the most abundant airborne taxon Agaricomycetes fungi dominating the initial phase and Sphingomonas bacteria becoming the most prevalent taxa toward the end of the experiment. Duplicate air samples collected upstream and downstream of the coil suggest that the system does not act as ecological filter or source/sink for specific microbial taxa during the duration of the experiment.

Influence of moisturizer and relative humidity on human emissions of fluorescent biological aerosol particles.

Utilizing the ultraviolet light-induced fluorescence (UV-LIF) measurement technique as embodied in the Waveband Integrated Bioaerosol Sensor (WIBS-4A), we evaluated the fluorescent particle emissions associated with human shedding while walking in a chamber. The mean emission rates of supermicron (1-10 µm) fluorescent particles were in the range 6.8-7.5 million particles per person-h (~0.3 mg per person-h) across three participants, for conditions when the relative humidity was 60%-70% and no moisturizer was applied after showering. The fluorescent particles displayed a lognormal distribution with the geometric mean diameter in the range 2.5-4 µm and exhibited asymmetry factors that increased with particle size. Use of moisturizer was associated with changes in number and mass emission rates, size distribution, and particle shape. Emission rates were lower when the relative humidity was reduced, but these differences were not statistically significant.

Thermal comfort, perceived air quality, and cognitive performance when personally controlled air movement is used by tropically acclimatized persons.

In a warm and humid climate, increasing the temperature set point offers considerable energy benefits with low first costs. Elevated air movement generated by a personally controlled fan can compensate for the negative effects caused by an increased temperature set point. Fifty-six tropically acclimatized persons in common Singaporean office attire (0.7 clo) were exposed for 90 minutes to each of five conditions: 23, 26, and 29°C and in the latter two cases with and without occupant-controlled air movement. Relative humidity was maintained at 60%. We tested thermal comfort, perceived air quality, sick building syndrome symptoms, and cognitive performance. We found that thermal comfort, perceived air quality, and sick building syndrome symptoms are equal or better at 26°C and 29°C than at the common set point of 23°C if a personally controlled fan is available for use. The best cognitive performance (as indicated by task speed) was obtained at 26°C; at 29°C, the availability of an occupant-controlled fan partially mitigated the negative effect of the elevated temperature. The typical Singaporean indoor air temperature set point of 23°C yielded the lowest cognitive performance. An elevated set point in air-conditioned buildings augmented with personally controlled fans might yield benefits for reduced energy use and improved indoor environmental quality in tropical climates.

Comparison of cardiac and pulmonary-specific quality-of-life measures in pulmonary arterial hypertension.

Studies systematically comparing the performance of health-related quality-of-life (HRQoL) instruments in pulmonary arterial hypertension (PAH) are lacking. We sought to address this by comparing cardiac and respiratory-specific measures of HRQoL in PAH. We prospectively assessed HRQoL in 128 patients with catheterisation-confirmed PAH at baseline and at 6, 12 and post-24 month follow-up visits. Cardiac-specific HRQoL was assessed using the Minnesota Living with Heart Failure Questionnaire (LHFQ); respiratory-specific HRQoL was assessed using the Airways Questionnaire 20 (AQ20); and general health status was assessed using the 36-item Short Form physical component summary (SF-36 PCS). The LHFQ and AQ20 were highly intercorrelated. Both demonstrated strong internal consistency and converged with the SF-36 PCS. Both discriminated patients based on World Health Organization (WHO) functional class, 6-min walking distance (6MWD) and Borg dyspnoea index (BDI), with the exception of a potential floor effect associated with low 6MWD. The LHFQ was more responsive than the AQ20 to changes over time in WHO functional class, 6MWD and BDI. In multivariate analyses, the LHFQ and AQ20 were each longitudinal predictors of general health status, independent of functional class, 6MWD and BDI. In conclusion, both cardiac-specific and respiratory-specific measures appropriately assess HRQoL in most patients with PAH. Overall, the LHFQ demonstrates stronger performance characteristics than the AQ20.

Extent and determinants of discrepancy between self-evaluations of weight status and clinical standards.

OBJECTIVES: To examine the extent and type of discordance between personal and medical classifications of weight status, and to examine the influence of sociodemographic factors on the misclassification of weight status. DESIGN/SETTING: The 1991 Health Promotion and Disease Prevention Supplement of the National Health Interview Survey, a nationally representative, cross-sectional survey of the U.S. population. PARTICIPANTS: Adults 18 years and older (N = 41,676). MEASUREMENTS AND MAIN RESULTS: Respondents' self-evaluations of weight status were compared to classification of their body mass index (BMI) by medical standards. Twenty-nine percent of respondents incorrectly classified their weight status relative to medical standards, and the nature of this error was variable. While 27.4% of overweight persons judged their weight to be "just about right," of those who did judge themselves to be overweight, 23.9% were in fact normal or underweight according to their BMI. Overall, 16.6% of persons underassessed their weight category, and 12.4% overassessed their weight category. Multivariate analysis revealed that sex, age, race, income, education, and occupation influenced the misclassification of weight status. CONCLUSIONS: A substantial proportion of Americans deviate from medical standards in their self-evaluations of weight appropriateness, and this lack of correspondence may reflect the normative judgments of various population subgroups. Clinical and public health programs that employ a uniform strategy or approach to the population may not be efficacious.

Structural characterization of the mouse Foxf1a gene.

Members in the superfamily of the forkhead/winged-helix transcription factors are known to play a critical role in the control of cell differentiation and tissue development. To understand the regulation and function of these genes, we have initially isolated and characterized the mouse Foxf1a gene, a novel forkhead gene predominantly expressed in the lung. The mouse gene consists of two exons with the forkhead domain contained in exon 1, and is located at band E1 on chromosome 8. Amino acid sequence of the mouse protein shares a high degree of homology to that of the corresponding human protein. The tissue specificity of expression of the mouse gene also resembles that found in the human gene. This gene is primarily expressed in the lung, and to a lesser extent in placenta and tissues in gastrointestinal tract. The transcription start site was mapped to 113 nucleotides upstream from the putative translation initiation site. The promoter of the mouse gene is highly GC rich and contains neither a CAAT nor a TATA box. A series of luciferase report constructs driven by the promoter and various deletions in the 5' flanking region of the gene were constructed and employed in transient transfection studies using a line of SV40 transformed mouse lymph node endothelial cells (SVEC4-10), which express the endogenous Foxf1a gene, and a line of mouse hepatoma cells (Hepa 1-6), in which Foxf1a is not expressed. To our surprise, these reporter genes are equally active in both cell lines. Further studies have shown that the proximal 5' flanking sequence and exon 1 of the endogenous gene are highly methylated in Hepa 1-6 cells but not in SVEC4-10 cells, suggesting that DNA methylation but not cell-specific transcription factor(s) regulates cell specificity of gene expression in these cultured cells.