Estrogen inhibits NPY secretion through membrane-associated estrogen receptor (ER)-α in clonal, immortalized hypothalamic neurons.

OBJECTIVE: Estrogen (E(2)) has an inhibitory effect on food intake by acting centrally in the hypothalamus, although it is not clear which hypothalamic neurons are involved in this process. Earlier studies from our lab and others have implicated neuropeptide Y (NPY) as an important central anorexigenic target of E(2). This study was designed to investigate whether E(2) can directly regulate NPY secretion and examine the cellular mechanisms and receptors responsible for this anorexigenic action of E(2). DESIGN: Clonal, murine, hypothalamic neuronal cell models, mHypoE-42 and mHypoA-2/12, were investigated for NPY secretory responses to 17ß-estradiol (E(2)) in the presence or absence of pharmacological inhibitors directed against the phosphatidylinositol-3-kinase (PI3K), mitogen-activated protein kinase (MAPK) and AMP-activated kinase (AMPK) pathways or to estrogen receptor (ER) specific agonists/antagonists. MEASUREMENTS: The presence of hypothalamic markers and characterization of neuronal cell lines was completed with polymerase chain reaction. NPY levels were measured using an enzyme immunoassay (EIA). The expression of ER-α and caveolin-1 was analyzed using immunocytochemistry. RESULTS: E(2) significantly decreased NPY secretion in both the mHypoE-42 and mHypoA-2/12 neurons. The E(2)-mediated repression of NPY secretion in the mHypoE-42 and mHypoA-2/12 neurons required ER-α, but not ER-ß, as shown by studies using an ER-specific agonist/antagonists. Additionally, using immunocytochemistry we detected colocalization of ER-α and the membrane-associated signaling protein caveolin-1. Importantly, using E(2)-conjugated bovine serum albumin (E(2)-BSA) and ER antagonists, we were able to show that the E(2)-mediated decrease in NPY secretion occurred through membrane-bound ER-α. Finally, using a combination of pharmacological inhibitors, we found that inhibition of the PI3K or AMPK pathway blocked the E(2)-mediated decrease in NPY secretion. CONCLUSION: These findings indicate that the central anorexigenic action of E(2) occurs at least partially through hypothalamic NPY-synthesizing neurons. This regulation of NPY secretion occurs through rapid signaling mechanisms through membrane bound ER-α.

Selenium accumulation by forage and grain crops and volatilization from seleniferous soils amended with different organic materials.

Greenhouse and field experiments were conducted to study the direct and residual effect of applying different organic materials on Se accumulation by crops and volatilization from seleniferous soils of northwestern India. Among organic manures, press mud and poultry manures proved 4-5 times more effective in reducing Se accumulation by different crops than farmyard manure. Efficiency of organic manures increased with increase in application rates. Application of both press mud and poultry manures reduced Se accumulation by 44-97% in wheat (Triticum aestivum) and rapeseed (Brassica napus) shoots in the greenhouse; 85-92% in wheat straw, 45-74% in wheat grains, 45-74% in rapeseed straw and 76-92% in rapeseed grains under field conditions. Both the manures remained highly effective in reducing Se accumulation by the crops following wheat and rapeseed and the extent of reduction varied from 50% to 87% in maize (Zea mays) and cowpeas (Vigna sinensis) in the greenhouse and 40-89% in maize and rice (Oryza sativa) crops under field situation. Rate of Se volatilization by wheat and rapeseed crops increased by 1.8-4.0 times; the greatest increase was observed with press mud followed by poultry manure, arhar (Cajanus cajan) leaves and farmyard manure. After 134d of incubation of 500g soil amended with 2% of plant tissues, the maximum amount of Se was volatilized with cowpea leaves (385ng) followed by wheat grains, leaves of maize, sugarcane (Saccharum officcinarum), arhar, poplar (Populus deltoides) and the control (91ng). The results of this study convincingly prove the usefulness of applying press mud and poultry manure in enhancing volatilization and retarding the transfer of Se from soil to plant in seleniferous soils.

Cold damage to the extremities: frostbite and non-freezing cold injuries.

The treatment of cold injuries to the periphery has advanced substantially in the last 10 years and optimal outcomes are only likely to be achieved if a multidisciplinary team uses the full range of diagnostic and treatment modalities that are now available. The internet and satellite phones with digital images allow immediate access by patients from remote geographical locations to hospital based specialists who can assess cold injuries and advise on early field care. The severity of frostbite injuries can now be assessed with triple phase bone scanning, allowing early prediction of likely subsequent tissue loss. Early hyperbaric oxygen therapy appears to improve outcome and the use of intravenous drugs such as synthetic prostaglandin analogues infusions and tissue plasminogen activator have been shown to reduce amputation rates. In non-freezing cold injuries the early administration of analgesia, the avoidance of secondary exposure, and the use of infrared thermography to assess the injuries are among newer approaches being introduced.

The generation of an array of clonal, immortalized cell models from the rat hypothalamus: analysis of melatonin effects on kisspeptin and gonadotropin-inhibitory hormone neurons.

Significant information on reproductive function has been generated based on the rat model, including many seminal discoveries. Yet little is known about the molecular and cellular events involved in control of reproductive function, mainly due to the pervasive lack of cell models from rat. We have therefore generated a wide array of cell lines using primary cell culture from the rat hypothalamus. Immortalization of the primary cells was achieved through retroviral transfer of T-antigen, followed by selection with geneticin. The mixed cell populations were subcloned and each clonal cell line was analyzed for expression of specific cellular markers. Each line has a distinct phenotypic profile, with expression of key neuroendocrine markers. We have functionally analyzed two clonal cell lines, rHypoE-7 and rHypoE-8, for hormones implicated in the control of gonadotropin-releasing hormone neuronal function through melatonin, specifically kisspeptin (KISS) and RF-amide-related peptide-3 (RFRP-3, the mammalian ortholog of the avian gonadotropin-inhibiting hormone, GnIH). We detected functional melatonin receptor activity, as each cell line exhibited inhibition of forskolin-stimulated 3'-5'-cyclic adenosine monophosphate (cAMP) accumulation. Upon treatment with 10 nM melatonin, we found that KISS gene expression was decreased in the rHypoE-8 cell line, while RFRP-3 was increased in the rHypoE-7 cell line. These results are in accordance with the differential regulatory functions of these two peptides, particularly on GnRH neuronal control. These cell lines will serve as novel tools for the analysis of the cellular and molecular mechanisms involved in hypothalamic control of a number of physiological processes described in the rat animal model.

Bioavailability of selenium to forage crops in a sandy loam soil amended with Se-rich plant materials.

Greenhouse experiments were conducted to study the bioavailability of selenium (Se) to sorghum (Sorghum bicolor L.), maize (Zea mays L.) and berseem (Trifolium alexandrinum L.) fodders in a sandy loam soil amended with different levels of Se-rich wheat (Triticum aestivum L.) and raya (Brassica juncea L. Czern) straw containing 53.3 and 136.7microg Seg(-1), respectively. Each of the fodder crops was grown after incorporation of Se-rich materials either individually or in a sequence - sorghum-maize-berseem by incorporating Se-rich straws only to the first crop. Application of Se-rich straws to each crop, even at the greatest rate of 1%, did not have any detrimental effect on dry matter yield of different crops. With increase in the level of wheat straw from 0% to 1%, Se content in sorghum and maize plants increased to greatest level of 1.3 and 1.5microg g(-1), respectively, at 0.3% of applied straw and thereafter it decreased consistently. In case of raya straw, the greatest Se content in sorghum (2.3microg g(-1)) and maize (3.0microg g(-1)) was recorded at 0.3% and 0.4% of the applied straw, respectively. Unlike sorghum and maize fodders, Se content in all the four cuts of berseem continued to increase with increase in the level of applied straws and for different cuts of berseem it varied from 1.6 to 2.3 and 3.4 to 4.3microg g(-1) in case of wheat and raya straw, respectively. Similar variations in Se content of different fodder crops were recorded when these were grown in the sequence - sorghum-maize-berseem; but Se content was 2-4 times lower than when each crop was grown with fresh application of Se-rich straw. None of the fodders absorbed Se in levels toxic for animal consumption (>5microg g(-1)) even at the greatest level of applied straw. Of the total Se added through Se-rich straws, utilization of Se was not more than 2% in case of sorghum and maize crops and up to 5% in case of berseem. At the time of sowing of sorghum, hot water soluble Se (HWS-Se) in soils treated with different levels of Se-rich wheat and raya straw, respectively, varied from 18 to 36 and 18 to 79microg kg(-1). Whereas in case of berseem, it varied from 33 to 101 and 33 to 154microg kg(-1), respectively. HWS-Se present at the sowing time of berseem was significantly correlated with Se content of all the four cuts in the soil treated with Se-rich straws; the coefficients of correlation 'r' varied between 0.79 (p0.05) and 0.99 (p0.001). Selenium-rich materials supplied significant amounts of S, P and micronutrients to the growing fodder crops. These investigations suggest that Se-rich raya and wheat straw may be disposed off safely in soils used for growing fodders.

Efficacy of repeated high-dose hepatitis B vaccine (80 microg) in patients with chronic liver disease.

Patients with chronic liver disease (CLD) respond poorly to standard hepatitis B (HBV) vaccine given as sequential 20 microg IM shots because of an overall impaired immune response. Many of these patients go on to liver transplantation and are at risk of acquiring recurrent or de novo HBV infection. To evaluate the efficacy and safety of high-dose (80 microg) IM HBV vaccination in patients with CLD who had previously failed to respond to a standard three-dose schedule of 40 microg IM vaccine given monthly. A retrospective review was undertaken at our institution of 79 patients with CLD who were treated with high-dose (80 microg) HBV vaccinations. All had previously failed a three-dose course of 40 microg HBV vaccine. An HBV vaccine response was defined as an anti-HBs titer greater than 100 mIU/ml. Liver enzymes, creatinine, age, prothrombin time, total vaccine dose, and MELD score were recorded. No adverse events were reported. Seventy-two per cent (57/79) of the subjects had an adequate response after receiving a mean total dose of 220 mug vaccine (range 80-800 microg). Twenty-eight per cent (22/79) of the subjects did not respond after receiving a mean total dose of 420 microg vaccine (range 240-720 microg). Non-responders had more severe hepatic disease defined as a higher mean total bilirubin level (p = 0.003) and a lower mean albumin level (p < 0.05). Age, prothrombin time, MELD score, and creatinine were not statistically significant between the responders and non-responders. Repeated high-dose (80 microg) HBV vaccination, in patients who do not respond to standard HBV vaccine doses, is safe and effective in the majority of patients with CLD.

The in vitro antibacterial/synergistic activities of Withania somnifera extracts.

The methanol, hexane and diethyl ether extracts from both leaves and roots of Withania somnifera were evaluated for the antibacterial/synergistic activity by agar plate disc-diffusion assay against Salmonella typhimurium and Escherichia coli. Different concentrations of Tibrim, a combination of rifampicin and isoniazid, were tested to find out the minimum inhibitory concentration (MIC), which came out to be 0.1 mg/ml for S. typhimurium and E. coli. From the six extracts tested, only methanol and hexane extracts of both leaves and roots were found to have potent antibacterial activity. A synergistic increase in the antibacterial effect of Tibrim was noticed when MIC of Tibrim was supplemented with these extracts.

Effects of dietary taurine on auditory function in full-term infants.

Three groups of neonates fed taurine supplemented infant formula, non-supplemented infant formula or breast milk, respectively, were studied from birth to 12 weeks of age. In addition to the measurement of whole blood taurine content, auditory function was monitored using auditory brainstem responses (ABRs) and transient evoked otoacoustic emissions (TEOAEs). The results showed a significant reduction in whole blood taurine concentration in the non-supplemented formula group. In addition, there was a significant drop in whole blood taurine levels in all 3 groups over the first four weeks of life. ABR wave latencies were significantly shorter in the non-supplemented group, with wave V showing the greatest reductions. Falling taurine levels after full-term birth may aid synaptic maturation/efficiency within the auditory system. TEOAE responses were significantly larger over the low to mid frequencies in the breast fed group suggesting improved middle ear function.

Functional suitability of commercially milled rice bran in India for use in different food products.

The effect of blending of commercially available full fat and defatted rice brans in India from modern multistage rice mills with parboiling/stabilizing facilities in different food products in comparison to those obtained from laboratory milling of rice is reported. Bread volume and cookie spread decreased but muffin volume increased with the addition of different types of bran to wheat flour, however, the cookie spread factor was not affected by addition of full fat rice bran. The yields of the extrudate were increased by the blending of full fat rice bran but were decreased by the addition of defatted rice bran. Rice brans could be added to different food products to the extent of 5-10%. However, the full fat rice bran could not be used for production of extruded snack food.