Immunoreactive ghrelin in human cord blood: relation to anthropometry,leptin, and growth hormone

BACKGROUND: Ghrelin is secreted by the stomach, the hypothalamus, and the placenta in humans and has growth hormone-secreting and orexigenic properties. Leptin is secreted mainly by the adipocyte, plays a major role in energy balance, and reflects fat mass in infants as well as adults. Leptin and ghrelin central effects are mediated, at least partly, through the neuropeptide Y/Y1 receptor pathway in the hypothalamus. METHODS: We determined whether ghrelin is also present in the fetus and investigated its relationship to leptin, growth hormone, birth weight, and calf and abdominal circumferences in 90 full-term neonates. RESULTS: Immunoreactive ghrelin was detected in all cord samples (mean +/- SD, 187 +/- 88 pmol/L; range, 66-594 pmol/L). In contrast to leptin, ghrelin concentrations of boys and girls were not statistically different. In female neonates, ghrelin is inversely correlated with anthropometric measures. In male neonates, ghrelin is positively correlated with leptin and negatively with growth hormone. CONCLUSION: The presence of significant ghrelin concentrations in all neonates before the first feeding is intriguing. Unlike the fairly constant concentrations and effects of leptin over the short term, the wide variability of ghrelin concentrations observed in newborns raises the possibility that ghrelin secretion causes short-term changes in feeding behavior. We suggest that ghrelin may play a physiologic role in the initiation of feeding.     

Longitudinal analysis of incomplete adolescent data.

An approach is illustrated for the analysis of longitudinal variables collected during adolescence. Since the method requires complete data, three techniques are compared for application when some individuals have missing values. These methods are implemented in a study of systolic blood pressures and dietary fat intakes collected longitudinally in adolescent girls. The value of adolescent systolic and fat variables in predicting systolic pressure in adult women is investigated.     

Detectability of fifteen aquatic micro/mesocosms

Zooplankton abundance and species richness in 15 untreated 12,000 L outdoor microcosms (n = 15) were monitored over the course of 1 year to document the inherent variability and statistical detectability between replicates. Statistical power analysis were applied to derive the statistically minimal detectable difference (MDD) between replicates with default values set at; α = 0.1 and β = 0.2. Copepod abundance and species richness generally demonstrated the best detectability at 0.31 and 0.16, respectively, (n = 15); 0.59 and 0.33 (n = 3). Total zooplankton abundance and species richness had the lowest detectabilities at 0.19 and 0.14, respectively, (n = 15); 0.35 and 0.3 (n = 3). Rotifers, due to their opportunistic and rapid life traits, had the lowest single-species abundance detectabilities at 0.54 (n = 15); 0.8 (n = 3), whereas macroinvertebrate species richness had the lowest detectability at 0.43 (n = 15); 0.7 (n = 3) over 1 year. We recommend a priori calibration of the study design relative to relevant MDDs. Moreover, it is suggested to consider alternatives to statistical null hypothesis testing.     

Association of a genetic marker at the corticotropin-releasing hormone locus with behavioral inhibition.

BACKGROUND: Behavioral inhibition to the unfamiliar (BI), a heritable temperamental profile involving an avoidant response to novel situations, may be an intermediate phenotype in the development of anxiety disorders. Corticotropin-releasing hormone (CRH) is a key mediator of the stress response through its effects on the hypothalamic-pituitary-adrenal axis and limbic brain systems. Transgenic mice overexpressing CRH exhibit BI-like behaviors, implicating this gene in the development of the phenotype. METHODS: We genotyped a marker tightly linked to the CRH locus in 85 families of children who underwent laboratory-based behavioral assessments of BI and performed family-based association analyses. RESULTS: We observed an association between an allele of the CRH-linked locus and BI (p =.015). Among offspring of parents with panic disorder, this association was particularly marked (p =.0009). We further demonstrate linkage disequilibrium between this marker and single nucleotide polymorphisms encompassing the CRH gene. CONCLUSIONS: These results are consistent with the possibility that variants in the CRH gene are associated with anxiety proneness.     

Improvement in sensitivity of allele-specific PCR facilitates reliable noninvasive prenatal detection of cystic fibrosis

BACKGROUND: Cell-free fetal DNA circulating in maternal blood has potential as a safer alternative to invasive methods of prenatal testing for paternally inherited genetic alterations, such as cystic fibrosis (CF) mutations. METHODS: We used allele-specific PCR to detect mutated CF D1152H DNA in the presence of an excess of the corresponding wild-type sequence. Pfx buffer (Invitrogen) containing replication accessory proteins and Taq polymerase with no proofreading activity was combined with TaqMaster PCR Enhancer (Eppendorf) to suppress nonspecific amplification of the wild-type allele. The procedure was tested on DNA isolated from plasma drawn from 11 pregnant women (gestational age, 11-19.2 weeks), with mutation confirmation by chorionic villus sampling. RESULTS: The method detected 5 copies of the CF D1152H mutant allele in the presence of up to approximately 100,000 copies of wild-type allele without interference from the wild-type sequence. The D1152H mutation was correctly identified in one positive sample; the only false-positive result was seen in a mishandled sample. CONCLUSIONS: This procedure allows for reliable detection of the paternally inherited D1152H mutation and has potential application for detection of other mutations, which may help reduce the need for invasive testing.     

Reoperative Lymph Node Dissection for Recurrent Papillary Thyroid Cancer and Effect on Serum Thyroglobulin

Background

Papillary thyroid cancer (PTC) has an excellent prognosis with current treatment methods. However, the rates of locoregional recurrence after initial surgical management remain significant. This study evaluates the effect of reoperative neck dissection for locoregional recurrence of PTC after initial total thyroidectomy and radioiodine therapy on the incidence of cervical recurrence and postoperative serum thyroglobulin (Tg) levels.

Methods

This is a retrospective cohort study conducted in a single academic medical center of patients with recurrent or persistent PTC isolated to the neck after previous total thyroidectomy with or without lymph node dissection and adjuvant I¹³¹ therapy who were treated with reoperative lymph node dissection. Outcomes including operative complications, pathologic findings, and effect of surgery on Tg levels and rates of recurrent disease were analyzed.

Results

From 2001 to 2010, a total of 61 patients had reoperative neck dissections for recurrent cervical PTC with a complication rate of 5?%. Seventy-two percent of patients were clinically free of detectable disease, and 28?% of patients had recurrent, persistent, or newly metastatic disease detected during the follow-up period. All patients had significant decreases in Tg levels, with a median 98?% reduction in preoperative levels. However, only 21?% of patients had an undetectable stimulated Tg (<0.5?ng/mL) during the follow-up period of 15.5?months.

Conclusions

Reoperative treatment of recurrent or persistent PTC can be performed with low complication rates, and Tg levels greatly decrease in most patients; however, few achieve undetectable stimulated Tg.     

An expanded model of faculty vitality in academic medicine

Many faculty in today’s academic medical centers face high levels of stress and low career satisfaction. Understanding faculty vitality is critically important for the health of our academic medical centers, yet the concept is ill-defined and lacking a comprehensive model. Expanding on previous research that examines vital faculty in higher education broadly and in academic medical centers specifically, this study proposes an expanded model of the unique factors that contribute to faculty vitality in academic medicine. We developed an online survey on the basis of a conceptual model (N?=?564) and used linear regression to investigate the fit of the model. We examined the relationships of two predictor variables measuring Primary Unit Climate and Leadership and Career and Life Management with an overall Faculty Vitality index comprised of three measures: Professional Engagement, Career Satisfaction, and Productivity. The findings revealed significant predictive relationships between Primary Unit Climate and Leadership, Career and Life Management, and Faculty Vitality. The overall model accounted for 59% of the variance in the overall Faculty Vitality Index. The results provide new insights into the developing model of faculty vitality and inform initiatives to support faculty in academic medical centers. Given the immense challenges faced by faculty, now more than ever do we need reliable evidence regarding what sustains faculty vitality.