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Background-Girls who are overweight/obese (OB) develop breast tissue but do not undergo menarche (the first menstrual period) significantly earlier than girls of normal weight (NW). It has been proposed that estrogen synthesized by adipose tissue may be contributory, yet OB do not have higher serum estrogen levels than NW matched on breast stage. We hypothesized that estrogen synthesized locally, in mammary fat, may contribute to breast development. This hypothesis would predict that breast development would be more advanced than other estrogensensitive tissues as a function of obesity and body fat. Methods-80 pre-menarchal girls (26 OB, 54 NW), aged 8.2-14.7 yrs, underwent dual-energy xray absorptiometry to calculate percent body fat (%BF), Tanner staging of the breast, breast ultrasound for morphological staging, trans-abdominal pelvic ultrasound, hand x-ray (bone age), a blood test for reproductive hormones, and urine collection to determine the vaginal maturation index (VMI), an index of estrogen exposure in urogenital epithelial cells. Results-When controlling for breast morphological stage determined by ultrasound, %BF was not associated with serum estrogen or gonadotropin (LH and FSH) levels or on indices of systemic estrogen action (uterine volume, endometrial thickness, bone age advancement, and VMI). Tanner breast stage did not correlate with breast morphological stage and led to misclassification of chest fatty tissue as breast tissue in some OB. Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Prevalence of Vibrio spp. with special reference to Vibrio parahaemolyticus (Vp) infection was assessed in Penaeus vannamei farms in Kancheepuram and Thiruvallur districts of Tamil Nadu during the period August 2014 to February 2015. Isolation and identification of bacteria from haemolymph, stomach and hepatopancreas of P. vannamei was done from all the farms for the prevalence of Vp infection. Based on the morphological, physiological and biochemical characterisation, 74 isolates were identified as Vp (35.14%), V. harveyi (21.62%), V. anguillarum (16.22%), V. campbellii (10.81%), V. mimicus (8.11%), V. alginolyticus (5.41%) and Pseudomonas aeruginosa (2.7%). The PCR results showed that there were 26 (35.14%) isolates positive for Vp specific toxR and tlh genes and negative for human pathogenic tdh and trh genes. All isolates were also negative for acute hepatopancreatic necrosis disease (AHPND) specific AP1, AP2, AP3 (pirAvp) and AP4 (pirAvp and pirBvp) genes. The study revealed that there was no AHPND causing Vp strain in farmed P. vannamei from two important coastal districts of Tamil Nadu, India.

Overweight/obese girls (OB) undergo thelarche but not menarche significantly earlier than normal weight girls (NW). It has been proposed that estrogen synthesized by adipose tissue may be contributory, yet OB do not have higher serum estrogen levels than NW matched on breast stage. We hypothesized that in OB, adipose tissue overlying the breast bud may be a ready source of estrogen that is sufficient to initiate thelarche because the primitive breast bud is intimately associated with the mammary fat pad during development (Anbazhagan Am J Anat ’91, Neville J Mammary Gland Biol Neoplasia ’98). Estrogen derived from mammary fat could act locally to induce thelarche but would not be detected in the circulation and therefore would not act systemically to induce uterine maturation/menses. To address this hypothesis, we measured reproductive hormones and imaged the breast, uterus, and ovaries in 80 pubertal, pre-menarchal girls (26 OB, 54 NW) aged 8.2-14.7 yrs. We used total percent body fat (%BF), determined by DXA, as a proxy for mammary fat, taking advantage of the positive correlation between these two measures (Novotny Am J Hum Biol ’11, Schautz Eur J Clin Nutr ’11, Zhu Eur Radiol ’16). We predicted that if estrogen derived from mammary fat contributes to breast maturation, then girls with higher %BF (and thus more mammary fat) would demonstrate immaturity of other estrogen-sensitive tissues (e.g. uterus, endometrial lining, vaginal epithelium) compared with girls of the same breast morphological stage (stages A-E based on Bruni et al. Adolesc Pediatr Gynecol ‘90) with lower %BF. OB were younger than NW (10.1 ± 1.1 vs. 11.3 ± 1.3 yrs, p<0.001) and more likely to be non-Hispanic Black or Hispanic (p=0.03). %BF ranged from 13.1-53.5% (3 rd -97 th percentiles). The distribution of Tanner breast and pubic hair stages was similar in NW and OB, and the full spectrum of breast development (A-E) was observed with stages D and E being the most common (59%) overall. Uterine volume, endometrial thickness, sex steroids (E1, E2, T, A’dione), and gonadotropins increased (p<0.001 for all), as expected, with breast morphological stage but %BF was not associated with any index of systemic estrogen action or reproductive hormones in a linear regression model controlled for breast morphological stage. These studies suggest that neither total %BF nor local (mammary) are clinically significant sources of estrogen capable of inducing breast development in OB. Taken together with the comparable gonadotropin levels observed in girls of the same breast morphological stage across a broad range of total %BF, these findings point to earlier activation of the hypothalamic-pituitary-ovarian axis in OB as the most likely cause of earlier thelarche in OB compared with NW. Longitudinal follow-up of this cohort is underway to investigate the...