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Biomedical subjects

H Tamura

Publications and source records attributed to H Tamura.

At least 55 records · Page 3Linked to original sources
PubMed2001

IgA nephropathy with complement deficiency.

We treated a female patient suffering from immunoglobulin A (IgA) nephropathy and congenital deficiency of the ninth component of the complement system (C9). She was admitted with hematuria and proteinuria, and the C9 deficiency was diagnosed based on the low hemolytic activity of 50 % of the hemolytic unit of the complements (CH50) and the normal C3 level in the plasma. Renal biopsy revealed mild mesangial proliferation, and immunofluorescence examination revealed mild mesangial deposits of IgA and C3 with the same distribution. We discuss the pathogenesis of IgA nephropathy and the role of the complements in its progression.

Adult↗
PubMed2001

Chronic central infusion of ghrelin increases hypothalamic neuropeptide Y and Agouti-related protein mRNA levels and body weight in rats.

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHS-R), was originally purified from the rat stomach. Like the synthetic growth hormone secretagogues (GHSs), ghrelin specifically releases growth hormone (GH) after intravenous administration. Also consistent with the central actions of GHSs, ghrelin-immunoreactive cells were shown to be located in the hypothalamic arcuate nucleus as well as the stomach. Recently, we showed that a single central administration of ghrelin increased food intake and hypothalamic agouti-related protein (AGRP) gene expression in rodents, and the orexigenic effect of this peptide seems to be independent of its GH-releasing activity. However, the effect of chronic infusion of ghrelin on food consumption and body weight and their possible mechanisms have not been elucidated. In this study, we determined the effects of chronic intracerebroventricular treatment with ghrelin on metabolic factors and on neuropeptide genes that are expressed in hypothalamic neurons that have been previously shown to express the GHS-R and to regulate food consumption. Chronic central administration of rat ghrelin (1 microg/rat every 12 h for 72 h) significantly increased food intake and body weight. However, it did not affect plasma insulin, glucose, leptin, or GH concentrations. We also found that chronic central administration of ghrelin increased both neuropeptide Y (NPY) mRNA levels (151.0 +/- 10.1% of saline-treated controls; P < 0.05) and AGRP mRNA levels (160.0 +/- 22.5% of saline-treated controls; P < 0.05) in the arcuate nucleus. Thus, the primary hypothalamic targets of ghrelin are NPY/AGRP-containing neurons, and ghrelin is a newly discovered orexigenic peptide in the brain and stomach.

Agouti-Related Protein↗
PubMed2001

[Light-wand (Trachlight) guided nasotracheal intubation].

We report that Trachlight-guided nasotracheal intubation might be achieved successfully and traumatically without removal of a stiff internal stylet. Endotracheal tube was mounted on a Trachlight with the stylet in position and bent to form a less sharp curvature than a right angle, namely 40-60 degree, at 7 cm proximal to the endotracheal tube tip. Forty-six patients scheduled for nasal intubation were studied to measure the intubation time and the success rate with the use of Trachlight. The tracheas were successfully intubated in 89% of patients. We suggest that Trachlight-guided nasotracheal intubation could be clinically feasible without traumatic complication when applied with a stiff stylet in position and this approach is a useful method for nasal intubation.

Humans↗
PubMed2001

[The clinical usefulness and transference of cefcapene pivoxil (CFPN-PI) into the maternal cubital blood, umbilical blood and amniotic fluid in premature rupture of the membranes].

We studied the transference of cefcapene pivoxil (CFPN-PI) into the maternal cubital blood, umbilical blood and amniotic fluid as well as its clinical usefulness. 58 pregnant women without complications who had a premature rupture of membranes after day 0 of the 36th week of pregnancy and delivered a child with a normal transvaginal labor were enrolled this study. As a result, we found that the maternal serum level of CFPN-PI reached a detectable level at 1 hr 15 min post dose, reached the maximum (Cmax) at 2 hr 30 min, and was maintained at 0.15-1.14 micrograms/ml until 4 hr 35 min. In the umbilical serum, the drug concentration reached a detectable level at 1 hr 45 min post dose, was maintained at Cmax of 0.40 microgram/ml from 3 hr 3 min until 4 hr 27 min, and showed a level as high as 0.14 microgram/ml at 7 hr 7 min. In the amniotic fluid, the drug concentration reached a detectable level of 0.09 microgram/ml at 2 hr 48 min post dose, reached Cmax at 3 hr 55 min, and was maintained at 0.15-0.61 microgram/ml until 13 hr 37 min. Concerning the prophylactic effects of CFPN-PI against infections, one case of puerperal intrauterine infection in the parent and two cases of neonatal infection were observed, showing an effectiveness of 95%. In terms of adverse events, neither abnormality in maternal laboratory test data suspected as due to CFPN-PI, nor abnormality in subjective and objective findings was observed. In the neonates, no abnormality suspected as due to CFPN-PI was detected, either, including growth retardation until the 3-month medical examination. We think that CFPN-PI can be a first choice drug for prophylaxis of infections in cases of premature rupture of membranes after the 36th week of pregnancy, because of convenience of oral administration, coupled with excellent safety and potent prophylactic effectiveness against infections resulting from a long term maintenance of high levels in the umbilical blood and amniotic fluid.

Adult↗
PubMed2000

Preparation and properties of cyclopentadienyl- and pentamethylcyclopentadienyl-titanium(IV) complexes with the C8H4S8 ligand, electrical conductivities of their oxidized species, and X-ray crystal structure of Ti(C5Me5)2(C8H4S8).

Ti(C5H5)2(C8H4S8) (1), Ti(C5Me5)2(C8H4S8) (2), [NMe4][Ti(C5H5)(C8H4S8)2] (3), and [NMe4][Ti(C5Me5)(C8H4S8)2] (4) [C8H4S8(2-) = 2-(4,5-ethylenedithio)-1,3-dithiole-2-ylidene)-1,3-dithiole-4,5- dithiolate(2-)] were prepared by reaction of Ti(C5H5)2Cl2, Ti(C5Me5)2Cl2, Ti(C5H5)Cl3, or Ti(C5Me5)Cl3 with Li2C8H4S8 or [NMe4]2[C8H4S8] in THF. They were oxidized by iodine, the ferrocenium cation, or TCNQ (7,7,8,8-tetracyano-p-quinodimethane) in CH2Cl2 or in acetone to afford one-electron-oxidized and over-one-electron-oxidized species, [Ti(C5H5)2(C8H4S8)].I3, [Ti(C5H5)2(C8H4S8)][PF6], [Ti(C5Me5)2(C8H4S8)].I3, [Ti(C5Me5)2(C8H4S8)][PF6], [Ti(C5H5)(C8H4S8)2].I0.9, [Ti(C5H5)(C8H4S8)2][TCNQ]0.3, [Ti(C5Me5)(C8H4S8)2].I2.4, and [Ti(C5Me5)(C8H4S8)2][TCNQ]0.3, with the C8H4S8 ligand-centered oxidation. They exhibited electrical conductivities of 1.6 x 10(-1) to 7.6 x 10(-4) S cm-1 measured for compacted pellets at room temperature. The crystal structure of 2 was clarified to consist of isolated dimerized units of the molecules through some sulfur-sulfur nonbonded contacts: monoclinic, P2(1)/c, a = 9.534(2) A, b = 18.227(2) A, c = 17.775(2) A, beta = 94.39(1) degrees, Z = 4.

Journal Article↗
PubMed2000

Observation of a spin-flip M1 transition in 7(lambda)Li.

Using a large-acceptance germanium detector array (Hyperball), we have observed a spin-flip M1 gamma transition between the ground-state spin doublet of (7)(Lambda)Li (3/2(+)-->1/2(+)). The observed energy of 691.7+/-0.6(stat)+/-1.0(syst) keV provides crucial information on the strength of the spin-spin interaction between a Lambda and a nucleon. This is the first observation of well-identified hypernuclear gamma transitions using germanium detectors.

Journal Article↗
PubMed2000

Investigation of hydrocephalus with three-dimensional constructive interference in steady state MRI.

We report four patients with various types of hydrocephalus in whom constructive interference in steady state (CISS) MRI disclosed the cause of the hydrocephalus. The imaging clearly delineated an abnormal contour of the ventricular system and intraventricular septa, essential information for surgical planning, including endoscopic surgery. Postoperative CISS images were useful for showing not only regression of hydrocephalus but also the patency of small fenestrations.

Aged↗
PubMed2000

A case of chronic myeloid leukemia with minor bcr-abl transcript following fluorouracil therapy for esophageal carcinoma.

We report here a very rare case of chronic myeloid leukemia (CML) with a minor bcr-abl transcript, which developed following long-term chemotherapy with fluorouracil for esophageal carcinoma. A 64-year-old male patient was diagnosed with CML. Four years earlier, he had suffered from esophageal carcinoma, which was treated by surgical resection followed by oral administration of fluorouracil (200 mg/day) for 4 years. Molecular analysis of his Philadelphia chromosome (Ph) using reverse-transcriptase polymerase chain reaction (RT-PCR) and subsequent sequencing revealed a minor bcr-abl transcript. The clinical course of this patient was aggressive with a short chronic phase of CML. This is the first reported case of secondary CML with a minor bcr-abl transcript.

Esophageal Neoplasms↗
PubMed2000

Immunopharmacological and immunotoxicological activities of a water-soluble (1-->3)-beta-D-glucan, CSBG from Candida spp.

We have established a convenient, two-step procedure to solubilize the yeast cell wall (1-->3)-beta-D-glucan using the combination of NaClO oxidation and DMSO extraction. Candida soluble beta-D-glucan (CSBG) was mainly composed of a linear beta-1,3 glucan with a linear beta-1,6-glucan moiety. In this study, we screened for several immunopharmacological activities of CSBG and found the following activities: (1) interleukin-6 synthesis of macrophages in vitro; (2) antagonistic effect for zymosan mediated-tumor necrosis factor synthesis of macrophages; (3) augmentation for lipopolysaccharide mediated tumor necrosis factor and nitrogen oxide syntheses of macrophages; (4) activation of alternative pathway of complement; (5) hematopoietic response on cyclophosphamide induced leukopenia; (6) the antitumor effect on ascites form tumor; (7) Enhanced vascular permeability; (8) priming effect on lipopolysaccharide triggered TNF-alpha synthesis; and (9) adjuvant effect on antibody production. These results strongly suggested that CSBG possessed various immunopharmacological activity.

Animals↗
PubMed2000

Glucocorticoids regulate pituitary growth hormone secretagogue receptor gene expression.

Glucocorticoids regulate growth hormone (GH) secretion by modulating both hypothalamic and pituitary function. At the level of the pituitary, glucocorticoids increase GH and GH-releasing hormone receptor (GHRH-R) gene expression. To test if glucocorticoids might also regulate the pituitary expression of the recently identified GH secretagogue (GHS) receptor, GHS-R; adult male rats were adrenalectomized or sham operated, and treated with the synthetic glucocorticoid (dexamethasone, 200 microg/day) or vehicle for 8 days. Pituitary GHS-R mRNA levels were assessed by reverse transcriptase polymerase chain reaction (RT-PCR). Adrenalectomy decreased pituitary GHS-R mRNA to 45% of vehicle-treated, sham-operated rats (P < 0.05). Administration of dexamethasone increased GHS-R mRNA levels in sham-operated as well as in adrenalectomized rats (199 +/- 24% (P < 0.05) and 369 +/- 48% (P < 0.01) of vehicle-treated controls). Addition of dexamethasone to primary rat pituitary cell cultures increased GHS-R mRNA levels in a dose- and time-dependent manner while the transcriptional inhibitor, actinomycin D, completely blocked the stimulatory action of dexamethasone. Taken together, these results suggest glucocorticoids directly increase pituitary GHS-R mRNA levels by stimulating GHS-R gene transcription.

Adrenalectomy↗
PubMed2000

Masculinizing effect of dihydrotestosterone on growth hormone secretion is inhibited in ovariectomized rats with anterolateral deafferentation of the medial basal hypothalamus or in intact female rats.

There is a striking sex difference in the pattern of growth hormone (GH) secretion in rats. Our previous studies showed that short-term administration of pharmacological doses of testosterone or dihydrotestosterone (DHT) masculinized the GH secretory pattern in ovariectomized (OVX) rats. The locus where testosterone or DHT interacts with the somatotropic axis is believed to be the hypothalamus. To obtain insights into this phenomenon, we administered a single dose of DHT s.c. to adult OVX rats at 0.01, 0. 1 or 1 mg/rat. Blood GH concentrations were measured in unanaesthetized rats. Six to 12 h after the s.c. administration of all three doses of DHT, the GH secretory pattern revealed a male-like secretory pattern as shown by episodic bursts occurring at 2-3-h intervals with low or undetectable trough levels. When anterolateral deafferentation of the medial basal hypothalamus (ALC) was performed, the blood concentrations revealed irregularly occurring small fluctuations, instead of the usual high bursts, but the basal GH concentration was significantly higher than that of OVX-sham-operated rats. DHT treatment did not elicit pulsatile GH secretion or alter GH concentrations in OVX rats with ALC. When intact adult female rats received DHT at a dose of 1 mg/rat, the male-like GH secretory pattern was not induced. These results suggest that neural inputs from the anterolateral direction to the medial basal hypothalamus are necessary for the masculinizing effect of DHT on the GH secretory pattern in OVX rats, and that oestrogen in intact female rats prevents the masculinizing effect of DHT.

Afferent Pathways↗
PubMed2000

Measurement of blood clearance time by Limulus G test of Candida-water soluble polysaccharide fraction, CAWS, in mice.

The Limulus G test, responsive to beta-1,3-D-glucan, is a well-established method for the detection of invasive fungal infection. We have recently found that Candida albicans released a water-soluble polysaccharide fraction (CAWS) into synthetic medium (Uchiyama et al., FEMS Immunol. Med. Microbiol. 24 (1999) 411-420). CAWS was composed of a mannoprotein-beta-glucan complex and activated Limulus factor G, and thus would be similar to the Limulus active substance in patient's blood. In a preliminary investigation, we have found that CAWS is lethal when administered intravenously in a murine system. In this study, we examined the toxicity and then the fate of CAWS in mice. The lethal toxicity was strain-dependent and strain DBA/2 was the most resistant. The toxicity was, at least in part, reduced by salbutamol sulfate and prednisolone treatment in the sensitive strains. On intravenous administration, the half clearance time (t1/2) was approximately 40 min in mice (DBA/2). On intraperitoneal administration, CAWS appeared in the blood with a peak concentration at 1 h. In order to establish a treatment plan, it is important to demonstrate the onset and the termination of deep-seated mycosis. The Limulus G test is suitable for the above purpose; however, it is necessary to fully understand the fate of beta-1,3-D-glucan in patients' blood.

Animals↗
PubMed2000

Assessment of lacunar hemorrhage associated with hypertensive stroke by echo-planar gradient-echo T2*-weighted MRI.

BACKGROUND AND PURPOSE: Echo-planar gradient-echo T2*-weighted MR imaging (GRE-EPI) may detect hypointense lesions representing microhemorrhages with high sensitivity. The aim of this study was to evaluate the effectiveness of GRE-EPI for detecting old lacunar hemorrhages in hypertensive patients with stroke. METHODS: GRE-EPI was performed with a 1.5-T MRI system in 198 hypertensive patients with stroke (130 patients with hemorrhagic stroke and 68 patients with multiple lacunar stroke) and 66 age-matched healthy elderly individuals. RESULTS: Concomitant hypointense foci were found in 84 (66%) patients with hemorrhagic stroke, 46 (68%) patients with multiple lacunar stroke, and 3 (5%) healthy elderly individuals. These hypointense foci were noted in the lentiform nucleus in 61 (47%) patients with hemorrhagic stroke, in the caudate nucleus in 9 (7%) patients, in the thalamus in 54 (42%) patients, in the corticosubcortical region in 57 (44%) patients, in the brain stem in 40 (34%) patients, and in the cerebellum in 32 (25%) patients. CONCLUSIONS: GRE-EPI is effective for the detection of lacunar hemorrhages induced by hypertension.

Acute Disease↗
PubMed2000

Central effect of ghrelin, an endogenous growth hormone secretagogue, on hypothalamic peptide gene expression.

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHS-R), was originally purified from the rat stomach. Like the synthetic GHSs, ghrelin specifically releases GH following intravenous administration. Also consistent with the central actions of GHSs, ghrelin-immunoreactive cells were shown to be located in the hypothalamic arcuate nucleus as well as the stomach. However, the central actions of ghrelin have not been elucidated. Here, we used radioactive in situ hybridization histochemistry to examine the effects of central administration of rat ghrelin on neuropeptide genes that are expressed in hypothalamic neurons that were previously shown to express GHS-R. We found that central administration of ghrelin increased both agouti-related protein (AGRP) mRNA levels (245.8 +/- 28.3% of the saline-treated controls; p < 0.01) in the hypothalamus and food intake (5.7 +/- 0.9 g ghrelin vs. 1.9 +/- 0.5 g saline; p < 0.05). On the other hand, 1 microg of rat ghrelin central administration did not alter the episodic GH release of freely moving adult male rats. Thus, ghrelin has an alternative role in stimulating food intake via an increase of AGRP rather than the release of GH from the pituitary.

Agouti-Related Protein↗