Neuroendocrine regulatory peptide-1 and -2: novel bioactive peptides processed from VGF.

Neuroendocrine regulatory peptides (NERP)-1 and NERP-2 are derived from distinct regions of VGF, a neurosecretory protein that was originally identified as a product of a nerve growth factor-responsive gene in rat PC12 cells. The amino acid length of human NERP-1 is 26, and that of rat NERP-1 is 25. Human and rat NERP-2 are both 38 amino acid peptides. NERPs colocalize with vasopressin in the storage granules of the paraventricular and supraoptic nuclei in the hypothalamus of both rats and humans. Administration of NERPs suppresses hypertonic saline- or angiotensin II-induced vasopressin release from the hypothalamus and pituitary. Thus, VGF is a precursor of multiple bioactive peptides with diverse neuroendocrine functions, and NERPs are novel hypothalamic peptides involved in the control of body fluid homeostasis by regulating vasopressin release.

A role for ghrelin in the central regulation of feeding.

Ghrelin is an acylated peptide that stimulates the release of growth hormone from the pituitary. Ghrelin-producing neurons are located in the hypothalamus, whereas ghrelin receptors are expressed in various regions of the brain, which is indicative of central-and as yet undefined-physiological functions. Here we show that ghrelin is involved in the hypothalamic regulation of energy homeostasis. Intracerebroventricular injections of ghrelin strongly stimulated feeding in rats and increased body weight gain. Ghrelin also increased feeding in rats that are genetically deficient in growth hormone. Anti-ghrelin immunoglobulin G robustly suppressed feeding. After intracerebroventricular ghrelin administration, Fos protein, a marker of neuronal activation, was found in regions of primary importance in the regulation of feeding, including neuropeptide Y6 (NPY) neurons and agouti-related protein (AGRP) neurons. Antibodies and antagonists of NPY and AGRP abolished ghrelin-induced feeding. Ghrelin augmented NPY gene expression and blocked leptin-induced feeding reduction, implying that there is a competitive interaction between ghrelin and leptin in feeding regulation. We conclude that ghrelin is a physiological mediator of feeding, and probably has a function in growth regulation by stimulating feeding and release of growth hormone.

Orexins (hypocretins): novel hypothalamic peptides with divergent functions.

The hypothalamus is the most important region in the control of food intake and body weight. The ventromedial "satiety center" and lateral hypothalamic "feeding center" have been implicated in the regulation of feeding and energy homeostasis by various studies of brain lesions. The discovery of orexin peptides, whose neurons are localized in the lateral hypothalamus and adjacent areas, has given us new insight into the regulation of feeding. Dense fiber projections are found throughout the brain, especially in the raphe nucleus, locus coeruleus, paraventricular thalamic nucleus, arcuate nucleus, and central gray. Orexins mainly stimulate food intake, but by the virtue of wide immunoreactive projections throughout the brain and spinal cord, orexins interact with various neuronal pathways to potentiate divergent functions. In this review, we summarize recent progress in the physiological, neuroanatomical, and molecular studies of the novel neuropeptide orexins (hypocretins).

Differential regulation of melanin-concentrating hormone and orexin genes in the agouti-related protein/melanocortin-4 receptor system.

Agouti protein and agouti-related protein (AGRP) antagonize alpha-melanocyte-stimulating hormone that binds to and activates the melanocortin-4 receptor (MC4-R) in the hypothalamus, thereby stimulating food intake. Melanin-concentrating hormone (MCH) and orexin are orexigenic peptides that specifically are synthesized in the lateral hypothalamus. MCH gene expression was augmented in A(y)/a (agouti) mice which overexpress agouti protein, but orexin mRNA was not. AGRP administered intracerebroventricularly into wild-type rats augmented MCH but not orexin gene expression. Also, SHU9119, a peptidergic antagonist of MC4-R, increased only MCH mRNA. These findings indicate that interruption of signaling at MC4-R activates the MCH but not the orexin gene. The biosyntheses of MCH and orexin are regulated through different pathways.

Bioreactor operated production of lipase: castor oil hydrolysis using partially-purified lipase.

A highly stable lipase from Pseudomonas aeruginosa KKA-5 was produced by batch cultivation technique employing shake flask and 5 L-bioreactor. The bioreactor was run at different airflow rates. Low airflow rates (1 and 3 L/min), did not lead to effective growth and lipase production. Growth increased by about one order and lipase production increased by about 6 times, at an airflow rate of 5 L/min. Lipase production occurred during decelerated cell growth. A highly stable lipase was produced which retained its activity in the running bioreactor, even after a period of one month. This stable lipase was partially-purified using ammonium sulphate precipitation technique. Castor oil was hydrolyzed using 300U crude and partially-purified lipase, each. Approximately 21-fold, partially-purified lipase could hydrolyze 81% castor oil within a period of 96 hr, where as only 63% hydrolysis was obtained, in 216 hour, when crude lipase was used.

Narcolepsy in orexin knockout mice: molecular genetics of sleep regulation.

Neurons containing the neuropeptide orexin (hypocretin) are located exclusively in the lateral hypothalamus and send axons to numerous regions throughout the central nervous system, including the major nuclei implicated in sleep regulation. Here, we report that, by behavioral and electroencephalographic criteria, orexin knockout mice exhibit a phenotype strikingly similar to human narcolepsy patients, as well as canarc-1 mutant dogs, the only known monogenic model of narcolepsy. Moreover, modafinil, an anti-narcoleptic drug with ill-defined mechanisms of action, activates orexin-containing neurons. We propose that orexin regulates sleep/wakefulness states, and that orexin knockout mice are a model of human narcolepsy, a disorder characterized primarily by rapid eye movement (REM) sleep dysregulation.

Orexins, orexigenic hypothalamic peptides, interact with autonomic, neuroendocrine and neuroregulatory systems.

We determined the immunohistochemical distributions of orexin-A and orexin-B, hypothalamic peptides that function in the regulation of feeding behavior and energy homeostasis. Orexin-A and -B neurons were restricted to the lateral and posterior hypothalamus, whereas both orexin-A and -B nerve fibers projected widely into the olfactory bulb, cerebral cortex, thalamus, hypothalamus, and brainstem. Dense populations of orexin-containing fibers were present in the paraventricular thalamic nucleus, central gray, raphe nuclei, and locus coeruleus. Moderate numbers of these fibers were found in the olfactory bulb, insular, infralimbic and prelimbic cortex, amygdala, ventral, and dorsolateral parts of the suprachiasmatic nucleus, paraventricular nucleus except the lateral magnocellular division, arcuate nucleus, supramammillary nucleus, nucleus of the solitary tract, and dorsal motor nucleus of the vagus. Small numbers of orexin fibers were present in the perirhinal, motor and sensory cortex, hippocampus, and supraoptic nucleus, and a very small number in the lateral magnocellular division of the paraventricular nucleus. Intracerebroventricular injections of orexins induced c-fos expression in the paraventricular thalamic nucleus, locus coeruleus, arcuate nucleus, central gray, raphe nuclei, nucleus of the solitary tract, dorsal motor nucleus of the vagus, suprachiasmatic nucleus, supraoptic nucleus, and paraventricular nucleus except the lateral magnocellular division. The unique neuronal distribution of orexins and their functional activation of neural circuits suggest specific complex roles of the peptides in autonomic and neuroendocrine control.

Experimental and clinical studies on balloon laserthermia using Nd: YAG laser for uterine endometrial cancer.

BACKGROUND AND OBJECTIVE: No conservative therapy for endometrial cancer exists. We therefore evaluated the new balloon laserthermia for such cases. STUDY DESIGN/MATERIAL AND METHODS: Experimental and clinical study. We examined experimentally porcine kidney and stomach, human resected uterus and clinically on 12 patients with endometrial cancer and two patients with hyperplasia. RESULTS: Temperatures were safely kept at the balloon surface. Laser irradiation should be performed for at least 10-15 min, 65-70 degrees C to produce a suitable degeneration, experimentally. Clinically, necrosis and degeneration to a depth of 4-6 mm was histologically observed. Eight patients with carcinoma and hyperplasia for which laserthermia was effective showed that the surface of cancer was smooth and the depth of invasion was in most cases up to 1/4 of muscle layer. CONCLUSION: Balloon laserthermia may be effective in early endometrial cancer or precancerous lesions. Its clinical usefulness should be investigated further.

Familial hypocalciuric hypercalcemia associated with mutation in the human Ca(2+)-sensing receptor gene.

Familial hypocalciuric hypercalcemia (FHH) is generally characterized by lifelong hypercalcemia without hypercalciuria and is inherited in an autosomal dominant manner. Affected individuals show abnormal parathyroid and renal responses to changes in the extracellular calcium concentration. A Japanese FHH family was screened for mutations in the Ca(2+)-sensing receptor gene by the polymerase chain reaction and single strand conformation polymorphism. The proband with hypercalcemia showed an abnormal pattern in exon 1 of the gene, whereas her two sisters with normocalcemia showed a normal pattern. The consanguineous parents with borderline serum calcium concentrations showed both patterns. Nucleotide sequence analysis identified a G-->C point mutation at nucleotide 118 that resulted in the conversion of the normal codon for proline into a codon for alanine at amino acid 40 (numbered according to the bovine complementary DNA). The proband was homozygous for the mutation, and the parents were heterozygous. These results imply that this mutation in the human Ca(2+)-sensing receptor gene causes FHH and that the dosage of the gene defect determines disease phenotype.

Prostalase: basic clinical research and preliminary clinical results with laser thermotherapy for symptomatic benign prostatic hyperplasia.

Prostalase¿ has a probe that emits a laser beam at 360 degrees . Targeted obstructive prostatic adenoma tissue was heated to above the cytotoxic threshold temperature of 45 degrees C. After successful canine prostate study, from September 1992 to April 1993, 45 patients were treated. This paper reports the 9 months results of this initial cohort of patients. Prostatic and periprostatic temperature mapping showed the mean temperature within the adenoma zone was 49 degrees C, while the periprostatic tissue remained within the safety level of less than 42.5 degrees C. The mean prostate volume reductions at 3, 6, and 9 months were 36, 33, and 38%, respectively. Those patients whose surgery was unsuccessful had prostatic tissue removed by TURP at 2 to 3 months. This tissue revealed a definite zone of coagulative necrosis. For the clinical assessment, patients were divided into urine retention (UR) and nonretention (NR) subgroups. At 9 months, 20 of the 32 UR subgroup and 10 of the 13 NR subgroup patients were available for assessment. Due to poor response or complications, 6 of the 26 UR patients (23%) required ancillary treatment. Hence, 20 of the 26 cases (77%) remained catheter free and their mean maximum uroflow +/- SE was 9.6 +/- 0.7 ml/sec. Based on a Siroky normogram only 7 of these 26 patients (27%) became unobstructed. Two of the 12 NR subgroup patients (17%) required ancillary treatment. The mean maximum uroflow +/- SE was 10.7 +/- 1.2 ml/sec.(ABSTRACT TRUNCATED AT 250 WORDS)