[Mechanism of generating neuropeptide family--selective regulation of gene transcription and processing enzyme].
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Amino Acid Sequence↗
Biomedical subjects
K Chihara
Publications and source records attributed to K Chihara.
[An open lung biopsy case of follicular bronchiolitis in rheumatoid arthritis].
A 49 year-old Japanese female with a clinical history of rheumatoid arthritis for 15 years developed fever, cough, sputa and exertional dyspnea. A chest x-ray showed right-sided pleural lesions in addition to persistent hyperinflation of the lungs for about four years. Pulmonary function tests showed combined obstructive and restrictive dysfunction, increased residual volume and reduced diffusing capacity. After an improvement of the pleural lesions, she underwent a right open lung biopsy in December 1988 which revealed follicular bronchiolitis and fibrino-fibrous pleural thickening. The pulmonary lesion of follicular bronchitis/bronchiolitis was reported in 1985 as a newly recognized pulmonary disorder among open lung biopsy cases. The present case was the second biopsy proven case of follicular bronchiolitis among the Japanese.
Arthritis, Rheumatoid↗
[Classification for bullous emphysema based on analysis of chest wall motion and pulmonary function before and after bullectomy].
This study proposed a new classification for giant bullae based on analysis of chest wall motion during breathing efforts in the supine position using serial chest X-rays and examined the pulmonary function before and after bullectomy. Twenty-three patients with giant bullae were divided into two groups. Eight patients (group A) had a phase shift between the diaphragm motion and the rib cage motion or abnormal diaphragmatic motion. Almost all of them had dyspnea on exertion, and their FEV1.0 and MVV% had dyspnea on exertion, and their FEV1.0 and MVV%pred. were impaired but improved soon after bullectomy. Fifteen patients (group B) had good coordination of the diaphragm motion and rib cage motion. Most of them had no dyspnea and had normal pulmonary function. In addition, patients of group B were divided into three subgroups based on a phase shift between the diaphragm motion and inflation-deflation of giant bullae during a run. First, three patients whose bullae synchronized with the diaphragm motion showed significant decrease of %VC after bullectomy, and took a year for the decreased FEV1.0 and MVV%pred. to recover following the operation. Secondly, three patients whose bullae lay on the diaphragm and reached maximum size in the early phase of expiration showed little change in pulmonary function after bullectomy. Third, three patients whose bullae reached a maximum size at the end of expiration showed improvement of %VC and FEV1.0 soon after bullectomy. Chest wall distortion, defined as one side of caudal chest and upper abdomen not moving symmetrically compared with the other side, was found in three patients whose bullae were located in the middle and lower lung fields.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Calcitonin gene-related peptide enhances spontaneous acetylcholine release from the rat motor nerve terminal.
The effect of synthetic rat calcitonin gene-related peptide (rCGRP) on neuromuscular transmission was examined in a superfused rat phrenic nerve-diaphragm preparation using an intracellular microelectrode technique. The superfusion with rCGRP (10(-8) to 2 x 10(-7) M) caused significant increases in the frequency of miniature endplate potentials (MEPPs). It, however, had no effect on the resting membrane potential, amplitude of MEPPs, or acetylcholine quantum size and content. Enhancement of spontaneous acetylcholine release from the motor nerve terminal by rCGRP was demonstrated.
Acetylcholine↗
Insulin-like growth factor I (IGF-I) production and the presence of IGF-I receptors in rat medullary thyroid carcinoma cell line 6-23 (clone 6).
To clarify whether insulin-like growth factor I (IGF-I) is an autocrine growth factor of rat medullary thyroid carcinoma (MTC) cell line, 6-23 (clone 6), IGF-I binding to MTC cell membranes, IGF-I levels in the conditioned culture medium of MTC cells and the effects of IGF-I on methyl-[3H]thymidine incorporation to MTC cells were examined. Scatchard analysis of saturation binding studies revealed the association constant and the maximal binding capacity were 1.0 x 10(9) M-1 and 199 fmol/mg of membrane protein, respectively. The binding of [125I]IGF-I to MTC cell membranes was inhibited by unlabeled IGF-I, IGF-II and insulin; the relative potencies were IGF-I greater than IGF-II much greater than insulin, suggesting the presence of type I IGF receptors in MTC cells. IGF-I levels in the conditioned culture medium of MTC cells were 120 +/- 3 pM (mean + SE). IGF-I (10(-10) to 10(-8) M) dose-dependently stimulated methyl-[3H]thymidine incorporation to MTC cells. These findings suggest a possible role of IGF-I as an autocrine growth factor for MTC cells.
Animals↗
Synaptic regulation of paraventricular arginine vasopressin-containing neurons by neuropeptide Y-containing monoaminergic neurons in rats. Electron-microscopic triple labeling.
Synaptic regulation of arginine vasopressin (AVP)-containing neurons by neuropeptide Y (NPY)-containing monoaminergic neurons was demonstrated in the paraventricular nucleus of the rat hypothalamus. NPY and AVP were immunolabeled in the pre- and the post-embedding procedures, respectively, and monoaminergic fibers were marked by incorporating 5-hydroxydopamine (5-OHDA), a false neurotransmitter. The immunoreaction for NPY was expressed by diaminobenzidine (DAB) chromogen, and that for AVP by gold particles. The DAB chromogen was localized on the surface of the membrane structures, such as vesicles or mitochondria, and on the core of large cored vesicles. Gold particles were located on the core of the secretory granules within the AVP cell bodies and processes. The incorporated 5-OHDA was found as dense cores within small or large vesicular structures. From these data, three types of nerve terminals were discernible: NPY-containing monoaminergic, NPY-containing non-aminergic, and monoaminergic fibers. The AVP cell bodies appeared to have synaptic junctions formed by these nerve terminals as well as by the unlabeled nerve terminals which have small clear vesicles and large cored vesicles. These different types of nerve terminals were frequently observed in a closely apposed position on the same AVP cell bodies. The functional relationships of these three types of neuronal terminals are discussed.
3,3'-Diaminobenzidine↗
Axons containing neuropeptide Y innervate arginine vasopressin-containing neurons in the rat paraventricular nucleus. Dual electron microscopic immunolabeling.
Synaptic connections between neurons immunoreactive for arginine vasopressin (AVP) and axon terminals immunoreactive for neuropeptide Y (NPY) were found in the magnocellular part of the paraventricular nucleus (PVN) in the rat hypothalamus. In pre-embedding double immunolabeling, NPY axon terminals labeled with diaminobenzidine (DAB) reaction product established synaptic junctions on the perikarya and neuronal processes of AVP neurons labeled with silver-gold particles. Ultrastructural morphology of the neurons was more suitably preserved by a combination of pre- and post-embedding procedures. The presynaptic NPY terminals contained many small clear vesicles and a few cored vesicles, and DAB chromogen (immunoreaction product) was located on the surface of the vesicular profiles and on the core. The postsynaptic AVP neurons possessed many large secretory granules labeled with gold particles. At the synaptic junctions, small clear vesicles were accumulated at the presynaptic membrane, and the postsynaptic membrane was coated with a dense accumulation of fine electron dense particles. The perikarya also received synapses made by immuno-negative axon terminals containing many small clear vesicles and a few cored vesicles. These terminals were found more frequently than those containing NPY.
Animals↗
Presence and release of calcitonin gene-related peptide in rat stomach.
Immunoreactive (IR)-calcitonin gene-related peptide (CGRP) was identified throughout the entire stomach of rats, being most highly concentrated in the pyloric region, and the concentrations in muscular layers being higher than those in mucosal layers. In addition, IR-CGRP was also present in the venous effluent from isolated perfused rat stomach, and its release was stimulated by dibutyryl cyclic AMP or theophylline but not by glucagon. Gel chromatography as well as HPLC of both tissue extracts and gastric perfusate showed three identical major peaks of IR-CGRP, one of which coeluted with synthetic CGRP. These results suggest that CGRP in the stomach plays a role in the regulation of gastric function.
Animals↗
Development of the neuronal system containing neuropeptide Y in the rat hypothalamus.
In the rat hypothalamus, neuropeptide Y-containing neurons first appeared on day 14.5 of gestation in the arcuate nucleus and in the dorsolateral hypothalamic area. Until birth neuropeptide Y-containing cell bodies increased in number in the arcuate, dorsomedial-lateral and paraventricular nuclei, but disappeared thereafter, but some cells remaining in the arcuate nucleus. In animals treated neonatally with monosodium L-glutamate to destroy the arcuate nucleus, neuropeptide Y-immunoreactivity became evident in many cells scattered in the magnocellular paraventricular and dorsomedial-lateral hypothalamic nuclei on day 16 but not on days 60 and 12. These neuropeptide Y-immunoreactive neurons which appeared in the paraventricular nucleus were also vasopressin-positive. Neuropeptide Y fibers, on the contrary, remarkably diminished in number on day 16, particularly in the paraventricular and dorsomedial-lateral nuclei, and the medial preoptic area, but made a considerable recovery on days 60 and 120. Hence it is probable that, in normal ontogenetic progress, the development of the neuropeptide Y fibers in these areas is inhibitorily affected by that of arcuate neuropeptide Y neurons.
Aging↗
GHRH treatment: studies in an animal model.
This study examined the effects of chronic deletion of circulating growth hormone-releasing (GHRH) and/or somatostatin (SRIF) on normal growing male rats, as well as the effects of exogenous GHRH (1-29)NH2 and/or SMS 201-995 administration on the growth of rats with hypothalamic ablation. Passive immunization with anti-rat GHRH goat gamma-globulin (GHRH-Ab) for 3 weeks caused a marked decrease in the levels of pituitary GH mRNA and severe growth failure. Treatment with anti-SRIF goat gamma-globulin (SRIF-Ab) for 3 weeks produced a more modest decrease in GH mRNA levels in the pituitary and a slight but significant inhibition of normal somatic growth. Hypothalamic ablation produced a marked decrease in the level of mRNA in the pituitary. Chronic continuous administration of GHRH (1-29)NH2 stimulated pituitary GH synthesis, elevated serum levels of insulin-like growth factor I and increased body weight gain in rats with hypothalamic ablation treated with replacement doses of cortisone, testosterone and L-thyroxine. Combined treatment with GHRH (1-29)NH2 and SMS 201-995 appeared to promote the effect of GHRH on pituitary GH release and somatic growth in these animals. The results suggest that continuous administration of GHRH will be useful in the treatment of children with growth retardation resulting from hypothalamic disorders. In children with combined GHRH and somatostatin deficiencies, the addition of somatostatin to a GHRH treatment regimen may produce better results.
Animals↗
Physiological role of somatostatin-mediated autofeedback regulation for growth hormone: importance of growth hormone in triggering somatostatin release during a trough period of pulsatile growth hormone release in conscious male rats.
In mammals including human, it is generally accepted that growth hormone (GH) can regulate its own secretion through an autofeedback mechanism in which somatostatin (SRIF) may be involved. To explore a physiological role of SRIF-mediated GH autoregulation, the effect of exogenous human GH administration on plasma rat GH response to [D-Ala2, Nle27]-human GH-releasing hormone-(1-28)-agmatine (hGHRH-analog), which does not crossreact with anti-rat GH-releasing hormone gamma-globulin (GHRH-Ab), was examined in conscious male rats treated with GHRH-Ab in the absence and presence of anti-SRIF gamma-globulin (SRIF-Ab). Enhanced SRIF release during a trough period of natural pulsatile GH secretion, suggested by the blunted GH response to exogenous hGHRH-analog, no longer occurred when major GH secretory bursts were abolished by GHRH-Ab treatment. On the other hand, when hGH was administered in GHRH-Ab-treated rats so as to simulate the quantity and dynamic change of GH in hypophysial portal circulation in rats exhibiting pulsatile GH secretion, hGHRH-analog-induced GH rises were significantly suppressed during the period corresponding to a GH trough. This suppression was completely prevented by simultaneous treatment with SRIF-Ab. Furthermore, administration of bovine GH, but not ovine prolactin, resulted in significant suppression of hGHRH-analog-provoked GH rises. These findings suggest that enhanced SRIF release during a trough period of spontaneous GH secretory rhythm is induced by the preceding GH secretory burst, and also suggest a possible role for SRIF-mediated GH autoregulation in a physiological state.
Agmatine↗
Effects of dopamine on immunoreactive growth hormone-releasing factor and somatostatin secretion from rat hypothalamic slices perifused in vitro.
The effects of dopamine (DA) on the release of GRF and somatostatin (SRIF) from the hypothalami of adult male rats were examined in an in vitro perifusion system using horizontal hypothalamic slices, 400 micron thick, including the median eminence and arcuate nuclei. When hypothalamic slices from five animals were perfused in a chamber with artificial cerebrospinal fluid (ACSF) at a flow rate of 100 microliters/min under a gaseous phase of 95% O2 and 5% CO2 at 37 C, rat (r) GRF- and SRIF-like immunoreactivities (-LI) were constantly detected in 30-min perifusates at least until 240 min of perifusion, and during the perifusion with 60 mM K+, the concentrations of rGRF-LI and SRIF-LI were increased 2.1 and 3.2 times, respectively, over basal values. Under the perifusion with ACSF containing normal goat gamma-globulin, the addition of 10(-8) M DA resulted in a significant increase in SRIF-LI from 8.2 +/- 0.3 to 14.3 +/- 1.5 pg/hypothalamus.30 min, but conversely, it caused a slight but significant decrease in rGRF-LI from 4.5 +/- 0.9 to 2.0 +/- 0.3 pg/hypothalamus.30 min. On the other hand, 10(-8) and 10(-6) M DA significantly stimulated rGRF-LI release from hypothalamic slices perifused with ACSF containing anti-SRIF goat gamma-globulin. These findings suggest that DA is a secretagogue for both SRIF and rGRF in the hypothalamus, but the rGRF-stimulating effect of DA is masked unless the action of endogenous SRIF is attenuated.
Animals↗
Alpha 2-adrenergic control of growth hormone (GH) secretion in conscious male rabbits: involvement of endogenous GH-releasing factor and somatostatin.
In an attempt to clarify the regulatory role in GH secretion of central alpha-adrenergic and dopaminergic mechanisms, the effects of iv administration of alpha 1- and alpha 2-adrenergic antagonists and dopaminergic antagonists were investigated in undisturbed conscious male rabbits. During a 6-h observation period (1030-1630 h), control animals demonstrated spontaneous pulsatile GH secretion with mean (+/- SEM) 6-h GH levels of 6.49 +/- 0.54 ng/ml (n = 16). Intravenous injection of yohimbine (YOM; an alpha 2-antagonist), chlorpromazine (CPZ), and haloperidol (HAL; dopamine and alpha-adrenergic antagonists) completely suppressed this pulsatile GH secretion (mean 6-h GH levels, 2.98 +/- 0.24, 3.48 +/- 0.24, and 2.91 +/- 0.29 ng/ml, respectively; P less than 0.001), whereas prazosin (an alpha 1-antagonist), pimozide (a selective dopamine antagonist), sulpiride, and YM-09151-2 (YM; D2-specific antagonists) failed to affect the GH secretory pattern (mean 6-h GH levels, 6.61 +/- 0.73, 6.71 +/- 0.56, 5.44 +/- 0.44, and 6.87 +/- 1.44 ng/ml, respectively). While an iv injection of 2 micrograms synthetic human GH-releasing factor-(1-44)-NH2 (hGRF) induced GH rises in prazosin-, HAL-, pimozide-, sulpiride-, and YM-treated rabbits as well as control rabbits, YOM and CPZ completely abolished these GH responses to hGRF injection. An iv injection of 10 ml antisomatostatin gamma-globulin caused a prompt and transient GH rise, followed by a sustained elevation of GH trough levels in normal control rabbits. YOM treatment completely abolished this highly oscillated GH release. However, suppression by YOM or CPZ of hGRF-induced GH rises was significantly reversed by iv administration of 10 ml antisomatostatin gamma-globulin. Therefore, the inhibitory effect of YOM and CPZ on both episodic GH release and hGRF-induced GH rises is due to the enhanced release of somatostatin, with a simultaneous suppression of endogenous GRF. On the other hand, HAL, possessing a weaker alpha-blocking action than CPZ, blunted pulsatile GH secretion, but only modestly suppressed hGRF-induced GH rises. These results suggest the following. 1) Central alpha 2-adrenergic mechanisms play a more important role in the regulation of GH secretion than alpha 1-adrenergic mechanisms in the rabbit as well as in other species. 2) The alpha 2-adrenergic blockade causes suppression of the release of hypothalamic GRF and enhanced release of endogenous somatostatin, thereby suppressing GH secretion.(ABSTRACT TRUNCATED AT 400 WORDS)
Adrenergic alpha-Antagonists↗
[Growth hormone--physiological roles of endogenous GRF and SRIF].
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Animals↗
[Gene encoding growth hormone-releasing hormone precursor: structure and expression control].
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Amino Acid Sequence↗
[A clinical study of six surgically treated patients with malignant tumors arising from chronic pleuritis and pyothorax].
During the clinical course of chronic pleuritis and pyothorax, we frequently have found abnormal clinical signs such as increased abnormal chest shadows, subjective symptoms, such as chest pain and bloody sputum, and the appearance of atypical cells in the pleural effusion. It is very difficult and important to diagnose differentially worsening of chronic inflammation and occurrence of malignant tumors. We have surgically treated six patients with malignant tumors arising from chronic pleuritis and pyothorax, who had the above abnormal signs. All of them were made, and their average age was fifty three years. Two patients exhibited increased abnormal chest shadows, 5 had subjective symptoms (5 with chest pain, 2 with bloody sputum and 2 with fever), and 1 had atypical cells in the pleural effusion. Two patients had suffered from chronic pleuritis, who both had received artificial pneumothorax therapy for pulmonary tuberculosis, and the other 4 patients had suffered from chronic pyothorax, with mean duration of thirty years. The pathological diagnoses were 2 cases each of malignant pleural mesothelioma, squamous cell carcinoma, and malignant fibrous histiocytoma. The two patients with squamous cell carcinoma had pleurocutaneous and bronchopleural fistula. The operative methods were tumor resections with pleuropneumonectomy performed in 2 patients and pneumonectomy in 1. Absolute non-curative operation was performed in 1 patient, and postoperative radiotherapy in 3 patients. All patients died of tumor recurrence, although five of them underwent reoperation, chemotherapy and radiotherapy. Their duration of survival ranged from 3 to 15 months with a mean of 9 months after appearance of malignant tumor signs.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Nd-YAG laser therapy in the field of pulmonary surgery].
Since 1980, we have treated 71 patients with malignant tumors and benign lesions by the Nd-YAG laser. The flexible fiberoptic bronchoscope with the local anesthesia was used for the treatments. Fifty-four cases were malignant tumors and 17 were benign lesions involving trachea and/or hilar bronchus. In malignant tumors, 41 cases were lung cancers, 24 of which were squamous cell carcinomas. Of 17 cases of benign lesions, 10 (58.5%) were introgenic stenoses. Palliative treatments were done for 36 cases of lung cancers, of which 23 died within 1 year after treatments. Four of 5 cases, which survived beyond 2 years, were adenoid cystic carcinomas. In 17 benign cases, 13 (76.5%) showed distinct improvements of symptoms and findings after treatments. Three patients died of massive bleedings. In these cases, severe stenoses were observed, which required treatments repeatedly. With the proper knowledge of the indications, limitations and complications, of YAG laser therapy it can be a beneficial mean for the management of benign lesions and malignant tumors in trachea and hilar bronchus.
Female↗
[Right ventricle support after lung resection].
It is very important to establish a method of determining the influence of lung resection on right ventricular function and to devise some therapeutic methods of supporting the right ventricle. However, there has been no systematic research on these issues. We found that echocardiographic demonstrated abnormal motion of the ventricular septum after right pneumonectomy and of the left ventricular wall after left pneumonectomy. We developed a triggered cuirass respirator and showed that it could support the right heart after a lung resection. We also found that the injection of SF6 Gas into the postpneumonectomy pleural space might be useful in supporting the right heart after a pneumonectomy.
Adult↗