Prolactin-releasing peptide increases food intake and affects hypothalamic physiology in Japanese quail (Coturnix japonica).

Prolactin-releasing peptide (PrRP) increases food intake in birds, whereas it is a potent satiety factor in rodents and fish. The aim of this study was to determine the effects of central injection of PrRP on feeding behaviors and hypothalamic physiology in juvenile Japanese quail (Coturnix japonica). Intracerebroventricular injection of 1,692 pmol of PrRP increased food intake for the first 90 min after injection but did not affect water intake. Quail treated with PrRP displayed more food and drink pecks, less time standing but more perching, and decreased defecations. Prolactin-releasing peptide-injected quail had increased c-Fos immunoreactivity in the dorsomedial nucleus (DMN) and arcuate nucleus (ARC) of the hypothalamus. Hypothalamic neuropeptide Y receptor subtypes 2 and 5 and melanocortin receptor 4 mRNAs were greater in PrRP- than vehicle-injected quail. In the DMN, there was less corticotropin-releasing factor (CRF) mRNA and in the ARC, more CRF mRNA in PrRP- than vehicle-injected chicks. Thus, PrRP increases food intake in quail, which is associated with changes in hypothalamic CRF and neuropeptide Y receptor gene expression and c-Fos-immunolabeled cells in the ARC and DMN.

Factors associated with acute otitis media in children due to penicillin intermediately resistant Streptococcus pneumoniae.

OBJECTIVES: This study was conducted to analyze the association between recent antimicrobial use and acute otitis media (AOM) due to Streptococcus pneumoniae intermediately resistant to penicillin (PISP). The influence of drug resistance on the clinical course of AOM was also assessed. METHODS: A retrospective cohort study was conducted in infants at Japanese Red Cross Medical Center, Tokyo. Children included in the study were under 24 months of age and diagnosed with AOM due to infection with S. pneumoniae between April 2002 and March 2007. Crude risk ratios (cRR) of PISP infection in cases with recent antibiotic use and other factors were obtained. The Mantel-Haenszel estimate was applied for the adjustment of cRR. RESULTS: Of 35 children, 13 had AOM due to penicillin-susceptible S. pneumoniae (PSSP) and 22 had AOM due to PISP. The adjusted risk ratio (aRR) of penicillin antibiotic use within 1 month was 1.99 (95% confidence interval (CI): 1.36-2.92), and the aRR of penicillin antibiotic use within 1 week was 1.93 (95% CI: 1.33-2.67). Recent use of penicillin antibiotics was an associated factor for AOM due to PISP. The clinical course was not clearly different between cases infected with PSSP and those with PISP. CONCLUSION: Recent use of penicillin antibiotics might be a selective pressure for PISP.

Effect of Garcinia cambogia extract on serum leptin and insulin in mice.

In this study we examined the effects of 3.3% Garcinia cambogia extract on 10% sucrose loading in mice for 4 weeks. Treatment was found to have no effect on body weight, fat pad weight or serum glucose level. On the other hand, serum total cholesterol, triglycerides, NEFA were observed. Levels of serum insulin and leptin, as well as the leptin/WAT ratio, were lower in the treated mice than in the control. These findings suggested that G. cambogia extract efficiently improved glucose metabolism and displayed leptin-like activity.

Intracerebroventricular injection of glucagon-like peptide-1 decreases monoamine concentrations in the hypothalamus of chicks.

1. We measured the concentrations of dopamine (DA), norepinephrine (NE), epinephrine (E) and 5-hydroxytryptamine (5-HT) in the hypothalamus of 21-d-old male brown-egg layer-type chicks after intracerebroventricular injection of glucagon-like peptide-1 (GLP-1). 2. The monoamine concentrations of the whole hypothalamus, paraventricular nucleus and lateral hypothalamic area were not significantly affected by GLP-1. 3. However, concentrations of DA, NE and E, but not 5-HT, in the ventromedial hypothalamic nucleus (VMH) were significantly decreased by GLP-1. 4. These observations suggest that the anorexigenic effect of GLP-1 involves catecholaminergic systems in the VMH in the chick.

Feeding increases 5-hydroxytryptamine and norepinephrine within the hypothalamus of chicks.

It is thought that hypothalamic 5-hydroxytryptamine (5HT) and norepinephrine (NE) are involved in the regulation of feeding in chicks. The present study was conducted to elucidate changes in the levels of extracellular 5HT and NE in the hypothalamus during feeding of chicks. In order to measure 5HT, NE and 4-hydroxy-3-methoxyphenylglycol (MHPG), which is a major metabolite of NE, we used brain microdialysis and high-pressure liquid chromatography with an electrochemical detector. After collecting samples to determine the basal levels of 5HT, NE and MHPG, food-deprived birds were given access to food. 5HT levels in the medial hypothalamus (MH) and lateral hypothalamus (LH) increased during the first 30 min of feeding, and then returned to basal levels. NE and MHPG in the LH increased during feeding, and remained elevated throughout the experiment. This study supports an idea that hypothalamic monoamines in the chick brain are involved in the regulation of feeding.

Suppression of neuropeptides' mRNA expression by herbal medicines in a rat model of peripheral inflammation.

The traditional Chinese medicines have been used clinically for a long time in some Asian countries, however, very few studies have been done to demonstrate the working mechanisms of these medicines using recently developed biochemical methodologies. In this study, we examined the anti-inflammatory effect of Huang-Lian-Jie-Du-Tang (HLJDT), a combination of herbs used in traditional Chinese medicine, on paw edema, thermal hyperalgesia and the mRNA increase of neuropeptides in spinal dorsal horn and hypothalamic neurons using a rat model of peripheral inflammation and hyperalgesia. The rats that received HLJDT from 3 days before the injection of complete Freund's adjuvant (CFA) into the plantar had significantly less edema and reduced thermal hyperalgesia compared to control rats that received CFA injection. The up-regulation of preprodynorphin mRNA in L4-5 dorsal horn neurons 8 hours after CFA injection that was observed in control rats, was also decreased in the HLJDT-treated rats. Moreover, there was a significant decrease in mRNA level of corticotropin-releasing factor in the paraventricular hypothalamic nucleus in the HLJDT-treated rats. These data demonstrate that HLJDT is anti-inflammatory, and produces changes in mRNA expression in dorsal horn and hypothalamic neurons. This is the first demonstrated that a traditional Chinese medicine can affect the excitability of neurons through an anti-inflammatory action.

Using postnatal age to determine test dates leads to misinterpretations when treatments alter gestation length: results from a collaborative behavioral teratology study in Japan.

A collaborative study was conducted by researchers from 18 laboratories that participated in the Behavioral Teratology Meeting in Japan. Pregnant Sprague-Dawley rats from four breeders received subcutaneous injections of nicotine (6 mg/kg body weight) from day 7 to day 20 of gestation. Results of preweaning tests were closely related to length of gestation, and prolonged gestation was seen in the nicotine group. The effects of nicotine were compared with and without the adjustment of the mean difference in gestational lengths. Without the adjustment (i.e., by employing assessment in terms of postnatal day) several perplexing results were obtained, indicating that the nicotine group developed more quickly than the control group on several preweaning tests. By employing the adjustment, these perplexing results disappeared, indicating that the nicotine group developed more slowly than the control group. The merit of employing gestational day (or postcoital age) as an alternative index is emphasized.

Effect of 8-methoxypsoralen plus long-wave ultraviolet (PUVA) radiation on mast cells. II. In vitro PUVA inhibits degranulation of rat peritoneal mast cells induced by compound 48/80.

Rat peritoneal mast cells incubated with a histamine liberator, compound 48/80, showed a significantly reduced capacity for releasing histamine following in vitro treatment with 0.1 micrograms/ml of 8-methoxypsoralen (8-MOP) plus 1-5 J/cm2 of long-wave ultraviolet (UVA) irradiation (PUVA). No remarkable inhibition in histamine release was observed in the cells treated with 8-MOP only. Irradiation with 5 J/cm2 of UVA alone exerted an inhibitory effect on histamine release, to a lesser extent than PUVA. PUVA irradiation did not bring any decrease in cell viability or any spontaneous release of histamine from irradiated cells as shown by phase-contrast microscopy and by histamine assay, respectively. These results suggest that PUVA treatment may cause a noncytotoxic disturbance at mast cell membranes or on surface receptors, leading to a decreased capacity for secreting chemical mediators.

Serum prolactin levels in eighty patients with sarcoidosis.

Serum prolactin levels were measured by radioimmunoassay in eighty patients (thirty-four males, forty-six females) with sarcoidosis before treatment. In twelve patients (15%) serum prolactin levels were more than two standard deviations above the mean of normal subjects. Hyperprolactinaemia was found most frequently (22%) in patients with radiological stage II; however, 14% of patients with stage I also had elevated serum prolactin levels. In most cases serum prolactin levels fell to within the normal range after treatment with corticosteroid in parallel with improvement of intrathoracic lesions. These findings suggest that hyperprolactinaemia may be due to hypothalamic involvement by sarcoid granulomata. We conclude that the measurement of basal serum prolactin levels using radioimmunoassay is a sensitive and practical method for screening patients with sarcoidosis for hypothalmic lesions.