Biomedical subjects

H Nakata

Publications and source records attributed to H Nakata.

At least 163 records · Page 9Linked to original sources

PubMed1995

[Bone mineral content in patients with bronchial asthma].

To study the factors related to bone mineral content (BMC) in patients with bronchial asthma (BA), we measured BMC of the whole body, bone mineral density (BMD) in the second, third, and fourth lumbar vertebrae (by dual energy X-ray absorptiometry, DXA XR-26, Norland), and pulmonary function in patients with BA. Subjects were 103 patients with BA and 194 age-matched normal controls. There was no significant difference in BMC or BMD between patients with BA and controls. In patients with BA, there was no significant difference in BMC or BMD between those who were taking steroids and those who were not. BMC and BMD were significantly correlated with age, body weight, VC, %VC, and FEV1, but not with the duration of steroid administration or the total steroid dose administered. These results suggest that patients with BA have normal BMC and that steroid administration does not affect bone mineral loss in such patients.

Asthma↗

PubMed1995

[Radiotherapy for carcinoma of the esophagus in aged patients].

One hundred fifty-four patients with esophageal carcinoma were treated with either irradiation alone or irradiation combined with surgery at the University of Occupational and Environmental Health Hospital between January 1980 and February 1992. The number of patients 75 years old and older was 25. In patients 74 years old and younger, the overall five-year survival rate by Kaplan-Meier method was 24.5%. The survival rate was best in the patients who were treated by a combination of irradiation and surgery. In patients 75 years old and older, the one-year survival rate was 59%, and the three-year rate was 20%. Aged patients had a tendency to be worse in performance status, and there was no correlation between treatment modality and survival time. We conclude that radiotherapy is useful for treating esophageal cancer in aged patients particularly when maintenance of the quality of life is considered.

Adult↗

PubMed1994

Regulation of interleukin-1 receptors and hypothalamic-pituitary-adrenal axis by lipopolysaccharide treatment in the mouse.

We measured iodine-125-labeled recombinant human interleukin-1 alpha (125I-IL-1 alpha) binding in the hippocampus, pituitary, liver, spleen and testis, and plasma adrenocorticotropic hormone (ACTH) and corticosterone levels after i.p. injection of various dose and treatment regimens of the bacterial endotoxin, lipopolysaccharide (LPS). Plasma ACTH and corticosterone levels were significantly increased at 2 h after acute administration of LPS (60 or 300 micrograms/mouse). 125I-IL-1 alpha binding in all peripheral tissues examined was significantly and comparably decreased at 2 h after a single injection of 30 micrograms or 300 micrograms LPS/mouse. On the other hand, 125I-IL-1 alpha binding in hippocampus was significantly decreased only after high dose administration of LPS (300 micrograms/mouse). In order to evaluate if activation of IL-1 in brain resulting in the observed decrease in 125I-IL-1 alpha binding may require more sustained exposure to endotoxin, we compared the effects of a single injection (60 micrograms/mouse) and two injections of LPS (30 micrograms/mouse each at 0 and 12 h). A single injection of LPS (60 micrograms/mouse) decreased 125I-IL-1 alpha binding in the testis but not in the hippocampus, while two LPS injections (30 micrograms/mouse each at 0 and 12 h) caused dramatic reductions in 125I-IL-1 alpha binding in both the hippocampus and testis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗

PubMed1994

Regulation of A2a adenosine receptor mRNA expression by agonists and forskolin in PC12 cells.

Modulation of A2a adenosine receptor (A2aAR) expression by adenosine agonists was studied in cultured PC12 cell lines. Exposure of A2aAR agonists such as 5'-N-ethylcarboxamidoadenosine (NECA) or CGS-21680 caused a transient increase followed by a decrease of A2aAR mRNA in PC12 cells in 10 h. This was followed by a gradual recovery to control levels by approximately 24 h. These changes were blocked by an adenosine receptor antagonist, xanthine amine congener. Forskolin also induced similar changes in the level of A2aAR mRNA. In addition, A2aAR numbers of PC12 cell membranes were significantly decreased during the NECA-exposure. These results suggest that A2aAR gene expression in PC12 cells is regulated by activation of A2aAR via a mechanism involving the second messenger, cAMP.

Adenosine↗

PubMed1994

[Combined radiotherapy and hyperthermia for Pancoast tumor].

Thirteen patients with Pancoast tumor were treated with combined radiotherapy and hyperthermia from April 1987 to December 1992. Radiotherapy was performed using 10 MV X-rays, and all patients received a total dosage of 40-118 Gy with conventional fractionation. Hyperthermia was performed once or twice a week within 30 minutes after each irradiation, using 8 MHz RF capacitive heating equipment (Thermotron RF-8). Partial response, defined as 50% or more regression of the tumor, was observed in 7/13 (54%) patients, and the median survival time was 25.2 months. Results of 14 patients treated with irradiation alone from July 1980 to December 1992 were also evaluated, and were used as a historical control. The partial response was 4/14 (29%) and the median survival time was 7.3 months. Radiotherapy combined with hyperthermia is an effective modality for treating Pancoast tumors.

Adult↗

PubMed1994

Distribution of mRNA for CCK-B receptor in the brain of Mastomys natalensis: abundant expression in telencephalic neurons.

The distribution of cholecystokinin B (CCK-B) receptors in the Mastomys brain was studied using Northern blot analysis and in situ hybridization technique. By Northern blot analysis using 32P-labeled cDNA probe, the cortex had the highest hybridization signal of CCK-B receptor mRNA in the brain. The olfactory bulb and hippocampus showed a moderate level of signals. In situ hybridization using 35S-labeled cRNA probes revealed a wide and region-specific distribution of CCK-B receptor mRNA in the telencephalon. Throughout the cerebral cortex, labeled cells were found in all layers, with higher intensities in layers II, V and VI. Pyramidal cells of the layer II of the piriform cortex showed the highest level of signals in the brain. In the hippocampus, most of the pyramidal cells of the Ammon's horn were labeled, although labeled cells were not detected in other layers. Distinct signals were also detected in the various amygdaloid nuclei, caudate-putamen, reticular thalamic nucleus, hypothalamic ventromedial nucleus and inferior colliculus. This distribution pattern may further support the prominent existence of CCK-B receptors in the brain particularly in the telencephalon.

Animals↗

PubMed1994

Location of agonist-dependent-phosphorylation sites in the third intracellular loop of muscarinic acetylcholine receptors (m2 subtype).

Muscarinic acetylcholine receptors (mAChR, human m2 subtype) expressed in Sf9 (Spodoptera frugiperda) cells using the baculovirus system were purified and subjected to phosphorylation by a mAChR kinase, which was partially purified from porcine cerebrum. Two bands with apparent molecular masses of 59 kDa and 39 kDa as determined by SDS/PAGE were found to be phosphorylated in an agonist-dependent manner. Both bands were labeled by the irreversible muscarinic ligand [3H]propylbenzilylcholine mustard. Molecular masses of the [32P]phosphorylated or [3H]propylbenzilylcholine-mustard-labeled bands decreased following treatment with N-glycanase. The 59-kDa and 39-kDa bands were converted to 52-kDa and 32-kDa bands, respectively, indicating that both the 59-kDa and 39-kDa bands contain the amino-terminal region where glycosylation sites are present. The ratio of incorporated [32P]phosphate and bound [3H]propylbenzilylcholine mustard was essentially the same for the 59-kDa and 39-kDa bands, indicating that all the phosphorylation sites reside in the sequence of 39 kDa from the amino-terminal region. The amounts of incorporated [32P]phosphate were estimated to be 10-11/receptor, with 7-8 serine and 3-4 threonine, but no phosphorylated tyrosine residues. Further treatment of [32P]phosphorylated or [3H]propylbenzilylcholine-mustard-labeled receptors with V8 protease indicated that the phosphorylation sites were not present in 30-kDa amino-terminal segment. These results indicate that the phosphorylation sites are localized in the range 30-39 kDa from the amino terminus, which consists of primarily the central part of the third intracellular loop. Consistent with this conclusion, a fusion protein containing glutathione S-transferase linked to a peptide corresponding to residues 227-324 of the central part of the third intracellular loop was found to be phosphorylated by the mAChR kinase in a heparin-sensitive manner.

Amino Acid Sequence↗

PubMed1994

Gastrin receptor genes are expressed in gastric parietal and enterochromaffin-like cells of Mastomys natalensis.

Although gastric enterochromaffin-like (ECL) carcinoid tumors are known to develop in patients with long-standing hypergastrinemia, the expression of the gastrin receptor gene in ECL cells has not yet been demonstrated. Therefore, this study was designed to examine gastrin receptor gene expression in ECL cells. Mastomys gastric mucosal cells isolated by enzyme dispersion were separated into 10 fractions (F1-10) by centrifugal elutriation. Each fraction was examined histologically to determine whether they contained ECL and/or parietal cells and Northern blot analysis was used to confirm the presence of histidine decarboxylase and H+, K(+)-ATPase gene expression. ECL cells were found only in fractions 1 and 2, whereas parietal cells were detected in fractions 6-10. Gastrin receptor gene expression was demonstrated in both parietal cell-rich and ECL cell-rich fractions. In addition, the gastrin receptor cDNA sequences obtained from the two of the fractions (F1 and 8) were identical. These results suggest that gastrin receptor genes are expressed in ECL cells as well as in parietal cells and that these receptors are identical.

Animals↗

PubMed1994

Complete regression of anaplastic astrocytoma by intravenous tumor necrosis factor-alpha (TNF alpha) after recurrence: a case report.

A 61-year-old male patient had a recurrence of anaplastic astrocytoma after initial chemoradiotherapy. After histologic confirmation of the recurrent tumor, he was treated with intravenous administration of human natural tumor necrosis factor-alpha (TNF alpha). Morphometric analysis of the tumor volumes demonstrated that the tumor continued to regress for 8 months during the course of intravenous TNF alpha therapy, and finally disappeared (total dose of intravenous TNF alpha, 785,000 JRU). The regression of tumor paralleled the neurologic improvement. He has had no signs of recurrence for 2 years. The present experience indicates that at least a certain population of malignant gliomas can be successfully treated by a systemic administration of TNF alpha without a major adverse effect.

Brain↗

PubMed1994

Gastrin receptor gene expression in several human carcinomas.

Gastrin has been shown to enhance the growth of various human tumors. The present study was designed to examine the gastrin receptor gene expression in various human carcinoma cell lines and in surgically resected carcinoma tissues. By Northern blot analysis, gastrin receptor mRNA was detected in 3 out of 7 small cell lung carcinoma cell lines. Gastrin receptor mRNA was also expressed in one out of 8 colon carcinoma cell lines and 2 out of 10 colon carcinoma tissues. Moreover, one of two small cell carcinoma cell lines of the stomach clearly expressed gastrin receptor mRNA. However, none of the gastric adenocarcinoma cell lines or surgically resected gastric adenocarcinomas tested had any detectable expression of gastrin receptor gene. These findings may suggest a role of gastrin receptor in the growth and differentiation of certain human carcinomas.

Adenocarcinoma↗

PubMed1994

[Regulation of G protein-coupled receptor kinase activity].

Recent progress on the activation of G protein-coupled receptor kinases is reviewed. beta-Adrenergic receptor kinase (beta ARK) is activated by G protein beta gamma -subunits, which interact with the carboxyl terminal portion of beta ARK. Muscarinic receptor m2-subtypes are phosphorylated by beta ARK1 in the central part of the third intracellular loop (I3). Phosphorylation of I3-GST fusion protein by beta ARK1 is synergistically stimulated by the beta gamma -subunits and mastoparan or a peptide corresponding to portions adjacent to the transmembrane segments of m2-receptors or by beta gamma -subunits and the agonist-bound I3-deleted m2 variant. These results indicate that agonist-bound receptors serve as both substrates and activators of beta ARK.

Animals↗

PubMed1994

[Effects of long-term endurance training on left ventricular dimensions and function in female distance runners].

Ultrasoundcardiogram (UCG) was measured to evaluate the effects of 2 years of endurance training on left ventricular dimensions and function in 3 female collegiate runners (mean age 19.7 years). All subjects had had an experience in endurance training as athletes and underwent the endurance training at the college for two years. Training consisted mainly of about 2 hours of running, 3 to 4 days a week. Training effects were found as measured by a 5000m-run pretraining (mean 19: 40.3 min) and post-training (mean 18: 49.3 min). The average increase in maximal oxygen uptake (VO2max/kg) after training was 9.4% (P < 0.05). UCG's dimensional variables such as LVDd, LVPWT and IVST in the post-training period did not reveal any increase. However, LVDs as a cardiac dimension showed a tendency to decrease, and functional variables such as SV, EF, FS showed a tendency to increase. This functional improvement appeared to be due to a decrease in LVDs. From these results, it is likely that the endurance training prior to this study might have helped an effective adaptation in their cardiac dimensions. Thus, we suggest that prior to this study cardiac dimensions had extended and enlarged to a certain extent, and then cardiac function might be improved as the subsequent physiological phenomenon.

Adult↗

PubMed1994

Sarcoidosis with hypercalcemia--successful treatment of renal insufficiency and renal calcification with prednisolone.

A case of muscular sarcoidosis accompanied by severe hypercalcemia (serum calcium 15.5 mg/dl), renal insufficiency and renal calcification is reported. Sarcoid granulomas were found in the biopsy specimens of the lung and the muscle. The administration of prednisolone effectively improved not only muscle weakness but also hypercalcemia, renal insufficiency and renal calcification. This is a rare case of sarcoidosis in which renal calcification remitted after treatment with prednisolone. It is thus suggested that prednisolone treatment should be considered not only for hypercalcemia, but also for renal insufficiency caused by renal calcification in patients with sarcoidosis.

Calcinosis↗

PubMed1994

[Bronchial hyperresponsiveness before and after percutaneous transluminal mitral commissurotomy in patients with mitral stenosis].

To study the effects of percutaneous transluminal mitral commissurotomy (PTMC) on bronchial responsiveness to inhaled methacholine in patients with mitral valve stenosis (MS), methacholine inhalation tests and pulmonary function tests were done in 10 patients with MS before and one week after PTMC. The mean log cumulative dose producing a 35% decrease in respiratory conductance (PD35Grs) was significantly higher after PTMC in nine patients in whom PTMC was successful (p < 0.05). There were no significant changes in the results of pulmonary function tests after PTMC. One patient had severe mitral regurgitation after PTMC, and a decrease in PD35Grs. Six of the other nine patients in whom PTMC was successful continued to be hyperresponsive to inhaled methacholine. These data show that bronchial hyperresponsiveness in patients with MS is less severe after PTMC, concomitant with the relief of pulmonary congestion, and they suggest that the remaining bronchial hyperresponsiveness is responsible for peripheral airway narrowing with organic remodeling.

Bronchial Hyperreactivity↗

PubMed1994

[A case of bronchiolitis obliterans organizing pneumonia: diagnostic utility of bronchoalveolar lavage and CT scan].

A 54-year-old female was admitted to our hospital because of abnormal shadows on chest X-ray at annual checkup. She complained of dyspnea on exertion. Chest X-ray findings showed an increase in density at the bilateral lower lung fields and unclearness of the silhouette of the heart and the diaphragm. CT scan findings revealed irregular opacities of various density with many small cystic changes and air bronchograms and air bronchiolograms. The pulmonary function test showed restrictive ventilatory disturbance and reduced diffusing capacity. BALF findings revealed an increase in the total cell count, an increase in the percentage of lymphocytes and a decrease in the OKT4+/OKT8+ ratio. TBLB specimen showed infiltration of mononuclear cells in alveolar septa and organizing exudate in alveolar ducts. These findings suggested a diagnosis of BOOP rather than IPF, and an open lung biopsy was performed. Open lung biopsy specimen showed obstructive bronchiolitis with polypoid granulation tissue and thickening of alveolar septa with infiltration of mononuclear cells, and she was diagnosed as having BOOP. She responded well to corticosteroid and is free from any abnormalities on chest X-ray, CT scan and pulmonary function test at present. Analysis of BALF and CT scan findings are useful for the differential diagnosis of BOOP and IPF.

Bronchoalveolar Lavage Fluid↗

PubMed1994

[123I-IMP clearance of the lung in pneumoconiosis].

We studied 123I-IMP lung clearance on 10 cases of pneumoconiosis and compared it with the data of 5 non-smoking young adults. After the venous injection of 111 MBq of 123I-IMP we collected the lung dynamic data using 1 frames/10 sec for 10 minutes and 1 frame/min for following 40 minutes. The time activity curve after the injection of 123I-IMP was obtained as follows: C(t) = A1e-k1t divided by A2e-k2t (k1, k2: slopes of the exponential component at the early and delayed phase). The 123I-IMP clearance was delayed in the patients group especially on the early phase and the k1 was lower than that of the normal group. Our results indicate that the pulmonary blood flow of the patients with pneumoconiosis decreased because of the advanced fibrotic change. This dynamic analysis may prove useful for the evaluation of the pneumoconiosis objectively and quantitatively.

Adult↗

PubMed1994

Irreversible data compression in chest imaging using computed radiography: an evaluation.

We studied the feasibility of a recently developed 20:1 to 25:1 compression technique for computed radiography (CR) using lung phantom images, and clinical cases were evaluated. We compared one original and two reconstructed CR films of the same image using compression ratios of 10:1 to 15:1, and 20:1 to 25:1, and the deterioration of image quality was carefully checked. Evaluation by subjective ranking of various abnormal opacities created for phantoms and clinical cases showed deterioration of image quality with 20:1 to 25:1 compression images. This was greatest for a single linear opacity (thin line) and least for reticulonodular opacities. Receiver operating characteristics (ROC) for pneumothorax, pulmonary nodules and reticulonodular opacities in newborns, infants, and adults revealed no significant differences among the original 10:1 to 15:1, and 20:1 to 25:1 compression images. We conclude that this new method of data compression of CR images is clinically applicable and useful.

Adult↗

PubMed1993

Functional characterization of a human brain cholecystokinin-B receptor. A trophic effect of cholecystokinin and gastrin.

We have cloned a human brain cholecystokinin (CCK)-B receptor cDNA and characterized its function by introducing it into Chinese hamster ovary (CHO) cells. The deduced amino acid sequence was highly conserved as compared with those of the gastrin receptors in Mastomys enterochromaffin-like cells (90%) and canine parietal cells (89%). Human brain CCK-B receptors possessed slightly but significantly higher affinities for CCK-8 than for gastrin I, while both ligands bound equally to Mastomys enterochromaffin-like cell-derived gastrin receptors. Both CCK-8 and gastrin I markedly augmented phosphoinositide hydrolysis and cytosolic free calcium levels in the CHO transfectants, indicating that the cloned CCK-B receptor could functionally couple with intracellular signaling molecules. Moreover, CCK-8 and gastrin I dose-dependently increased [3H]thymidine incorporation of the CHO transfectants in serum-free medium and promoted cell growth. The CCK-B receptor mRNA was abundantly expressed in particular areas of the human brain and stomach, such as the cerebral cortex and mucosa of the gastric fundus. This is the first demonstration of trophic effects of CCK and gastrin through the normal human brain CCK-B receptor. The availability of this receptor cDNA will help to clarify the precise role of CCK in the central nervous system as well as digestive organs.

Amino Acid Sequence↗