Neuroanatomical specificity of prolactin-induced hyperphagia in virgin female rats

Intracerebroventricular (i.c.v.) administration of PRL increases food intake in virgin female rats but the brain site(s) at which PRL acts to promote feeding behavior is not known. The present studies investigated the role of the paraventricular nucleus (PVN), ventromedial nucleus (VMH), and medial preoptic nucleus (MPOA) in the hyperphagic actions of PRL. Ad-libitum-fed virgin female rats received twice daily site-specific injections of PRL (800 ng) over a period of 10 days. Only subjects demonstrating regular vaginal cyclicity were included in the study. Food intake, body weight, and vaginal cyclicity were measured daily. Results showed that PRL significantly increased food intake when injected into the PVN. A nonsignificant trend towards a hyperphagic response in the last 5 days of testing was observed in rats receiving intra-VMH injections of PRL, and the MPOA was not responsive to the feeding-stimulating properties of PRL. None of the manipulations affected body weight or vaginal cyclicity as demonstrated by vaginal smears. In sum, the present results reveal that one brain site at which PRL acts to increase food intake is the PVN, but these studies do not rule out the possibility that the effects of PRL on food intake may also involve other brain areas.     

Long-term effects on feeding and body weight after stimulation of forebrain or hindbrain CRH receptors with urocortin

Research on the contribution of CRH receptor stimulation to energy homeostasis has focused on forebrain substrates. In this study, we explored the effects of caudal brainstem administration of the CRH receptor agonist, urocortin, on food intake and body weight, and on plasma glucose and corticosterone (CORT) in non-deprived rats. Urocortin (0, 0.3, 1, 3 microg) delivered, respectively, to the fourth and lateral ventricles yielded substantial suppression of food intake measured 2, 4 and 24 h later. A significant but more modest anorexia was observed between 24 and 48 h after injection. Intake responses did not differ between the injection sites, but body weight loss measured 24 h after lateral-i.c.v. injection was substantially greater than that after fourth-i.c.v. injection. Fourth-i.c.v. urocortin administration (3 microg) produced substantial elevations in plasma glucose and CORT that were not distinguishable in magnitude and duration from responses to lateral-i.c.v. delivery. Unilateral microinjection of urocortin into the dorsal vagal complex significantly reduced 24-h food intake at a dose (0.1 microg) that was subthreshold for the response to ventricular administration, suggesting that fourth-i.c.v. effects are mediated in part by stimulation of CRH receptors in this region of the caudal brainstem. The results indicate that similar effects can be obtained from stimulation of anatomically disparate populations of CRH receptors, and that interactions between forebrain and hindbrain structures should be considered in the evaluation of CRH contributions to food intake and body weight control.     

青少年摄入不同剂量乳糖与氢呼气量关系的研究

目的　探讨广东青少年摄入不同剂量乳糖与氢呼气量的关系。方法　采用不同剂量乳糖进行氢呼气试验。选择广州、珠海、佛山、韶关 4个城市 7～ 1 8岁健康的中小学生 92 6名 ,摄入2 5 0 0g纯乳糖进行氢呼气试验 ,对检出为乳糖酶缺乏者 ,先后服用含乳糖 1 2 5 0、6 2 5g的奶粉 ,进行牛奶氢呼气试验。结果　广东省中小学生乳糖酶缺乏率为 73 7%。乳糖酶缺乏者出现最大呼氢峰值的年龄是 1 3岁 ,其中乳糖不耐受者出现最大呼氢峰值的年龄是 1 2岁。摄入乳糖 2 5 0 0、1 2 5 0、6 2 5g的呼氢峰值分别是 6 2 1 1、4 0 89、37 92mol/L ,差异有显著性 (U1 =1 6 76 3 5 0 ,U2 =5 739 0 0 ,P <0 0 1 )。摄入 2 5 0 0g乳糖受试组乳糖不耐受的呼氢峰值明显高于乳糖吸收不良者 (U =2 31 1 4 0 0 ,P<0 0 5 )。摄入 2 5 0 0、1 2 5 0、6 2 5g乳糖出现最大呼氢峰值时间分别是在摄入后 1、2、3h ,最高的乳糖酶缺乏检出率分别是在摄入后 2、2、3h。结论　氢呼气试验的呼氢峰值随乳糖摄入量的减少而降低 ,乳糖酶缺乏发生时间有随乳糖摄入量的减少而推后的趋势     

小剂量红霉素预防早产儿喂养不耐受的随机对照研究

目的:探讨小剂量红霉素预防早产儿喂养不耐受的疗效及安全性。方法:63例胎龄≤34周,出生体重≤1800g,并除外消化道先天畸形的早产儿被随机分配到对照组和预防用药组(用药组),其中用药组于生后第3d常规给予红霉素10mg/(kg·d),1次/8h,共7d。结果:用药组的喂养不耐受率(26·67%)低于对照组(45·5%),但差异无统计学意义(χ2=2·393,P>0·05)。两组达到完全经肠道喂养的时间、黄疸持续时间和每天大便次数均有明显差异(P<0·05或P<0·01),而平均住院时间的差异则无显著性意义。两组均无心律失常的发生。用药组未出现药物相关性肝功能损害。结论:小剂量红霉素预防早产儿喂养不耐受是安全有效的,但这些结果有待多中心大样本研究的证实。     

有关乳糖不耐受的研究进展

乳糖不耐受与人类尤其是婴儿期的营养和健康密切相关,影响人类对乳及其制品的摄入。了解乳糖不耐受的分型、临床症状及诊断,对维持人体健康、降低老年人群骨质疏松的危险性有着重要意义。对乳糖酶基因多态性的研究为人类了解、预防和控制该症提供了广阔的前景。乳糖酶分型的检测有可能成为对骨质疏松症患者进行早期基因筛查的一种行之有效的手段,而如何对乳糖不耐受进行改善和控制,尚需从多方面加以深入研究。     

Clinical improvement in patients with orthostatic intolerance after treatment with bisoprolol and fludrocortisone

Orthostatic intolerance is the development of disabling symptoms upon assuming an upright posture that are relieved partially by resuming the supine position. Postural tachycardia syndrome (POTS) is an orthostatic intolerance syndrome characterized by palpitations because of excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope. Patients usually undergo extensive medical, cardiac, endocrine, neurologic, and psychiatric evaluation, which usually fails to identify a specific abnormality. The authors investigated the autonomic and hemodynamic profile of patients with POTS and the effectiveness of bisoprolol and fludrocortisone. The authors evaluated 11 female patients with POTS before and after medical treatment with a cardioselective bisoprolol -blocker or fludrocortisone, or both, and 11 age-matched control patients. Variability of heart rate and systolic blood pressure was assessed by fast Fourier transform, and spontaneous baroreceptor gain was assessed by use of the temporal sequences slope and index. Modelflow was used to quantify hemodynamics. Symptoms in all patients improved greatly after medication. The autonomic and hemodynamic impairment observed in patients with POTS, particularly after orthostatic stress, is treated effectively with bisoprolol or fludrocortisone or both. These results need further confirmation in a controlled double-blind study. Proper medical treatment improves dramatically the clinical and autonomic-hemodynamic disturbances observed in patients with POTS. The data support the hypothesis that POTS is the result of a hyperadrenergic activation or hypovolemia during orthostasis.     

Mass spectrometric and high performance liquid chromatography profiling of the venom of the Brazilian vermivorous mollusk Conus regius: feeding behavior and identification of one novel conotoxin.

Carnivorous mollusks belonging to the genus Conus paralyze their prey by injecting a rich mixture of biologically active peptides. Conus regius is a vermivorous member of this genus that inhabits Brazilian tropical waters. Inter-, intra-species and individual variations of cone snail venom have been previously reported. In order to investigate intra-specific differences in C. regius venom, its feeding behavior and the correlation between these two factors, animals were pooled according to gender, size and season of collection, and their venom composition was compared by high performance liquid chromatography (HPLC). Both the whole venom and one specific peak were monitored by HPLC. Chromatographic profiles revealed no significant differences in their peak areas, indicating that the venom composition, based solely in the presence or absence of the major peaks, is stable regardless of season, gender and size. Therefore, analysis of one given toxin, eluting in one of the major peaks, is representative among the population. Moreover, this work presents the identification of one novel conotoxin (rg11a), which amino acid sequence was deduced by mass spectrometry.     

Association of long-duration breastfeeding and dental caries estimated with marginal structural models

PurposeTo estimate the association between breastfeeding 24 months or beyond and severe early childhood caries (S-ECC).MethodsWithin a birth cohort (n = 715) from low-income families in Porto Alegre, Brazil, the age 38-month prevalence of S-ECC (≥4 affected tooth surfaces or ≥1 affected maxillary anterior teeth) was compared over breastfeeding duration categories using marginal structural models to account for time-dependent confounding by other feeding habits and child growth. Additional analyses assessed whether daily breastfeeding frequency modified the association of breastfeeding duration and S-ECC. Multiple imputation and censoring weights were used to address incomplete covariate information and missing outcomes, respectively. Confidence intervals (CIs) were estimated using bootstrap resampling.ResultsBreastfeeding 24 months or beyond was associated with the highest adjusted population-average S-ECC prevalence (0.45; 95% CI, 0.36 to 0.54) compared with breastfeeding less than 6 months (0.22; 95% CI, 0.15 to 0.28), 6–11 months (0.38; 95% CI, 0.25 to 0.53), or 12–23 months (0.39; 95% CI, 0.20 to 0.56). High-frequency breastfeeding enhanced the association between long-duration breastfeeding and caries (excess prevalence due to interaction: 0.13; 80% CI, −0.03 to 0.30).ConclusionsIn this population, breastfeeding 24 months or beyond, particularly if frequent, was associated with S-ECC. Dental health should be one consideration, among many, in evaluating health outcomes associated with breastfeeding 24 months or beyond.     

Examining the side effects of sucrose for pain relief in preterm infants: a case-control study

Sucrose solution is recommended as relevant pain relief management in neonates during acute painful procedures; however, only a few studies have analyzed the potentially adverse effects of sucrose administration to preterm neonates. The goal of this study was to examine the potential side effects of sucrose for pain relief in preterm infants, assessing feeding and weight gain during hospitalization and their feeding patterns postdischarge. The study sample consisted of 43 preterm neonates divided into two groups: a sucrose group (SG, n=18) and a control group (CG, n=25) in which no sucrose was administered. The SG received 0.5 mL/kg 25% oral sucrose for 2 min prior to all acute painful procedures during three consecutive days. A prospective review of medical charts was performed for all samples. The study was done prior to implementation of the institutional sucrose guidelines as a routine service, and followed all ethical requirements. There were no statistically significant differences between groups in terms of weight gain, length of stay with orogastric tubes, and parenteral feeding. Postdischarge, infant nutritional intake included feeding human milk to 67% of the SG and 74% of the CG. There were no statistically significant differences between groups regarding human milk feeding patterns postdischarge. Neonate feeding patterns and weight gain were unaffected following the short-term use of sucrose for pain relief.