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Biomedical subjects

H Naito

Publications and source records attributed to H Naito.

At least 91 records · Page 5Linked to original sources
PubMed1999

Exercise-induced alterations in skeletal muscle myosin heavy chain phenotype: dose-response relationship.

This study investigated the effects of exercise training duration on the myosin heavy chain (MHC) isoform distribution in rat locomotor muscles. Female Sprague-Dawley rats (120 days old) were assigned to either a sedentary control group or to one of three endurance exercise training groups. Trained animals ran on a treadmill at approximately 75% maximal O2 uptake for 10 wk (4-5 days/wk) at one of three different exercise durations (30, 60, or 90 min/day). Training resulted in increases (P < 0.05) in citrate synthase activity in the soleus and extensor digitorum longus in both the 60 and 90 min/day duration groups and in the plantaris (Pla) in all three exercise groups. All durations of training resulted in a reduction (P < 0.05) in the percentage of MHCIIb and an increase (P < 0.05) in the percentage of MHCIIa in the Pla. The magnitude of change in the percentage of MHCIIb in the Pla increased as a function of the training duration. In the extensor digitorum longus, 90 min of daily exercise promoted a decrease (P < 0.05) in percentage of MHCIIb and increases (P < 0.05) in the percentages of MHCI, MHCIIa, and MHCIId/x. Finally, training durations >/=60 min resulted in an increase (P < 0.05) in the percentage of MHCI and a concomitant decrease (P < 0.05) in the percentage of MHCIIa in the soleus. These results demonstrate that increasing the training duration elevates the magnitude of the fast-to-slow shift in MHC phenotype in rat hindlimb muscles.

Animals↗
PubMed1999

Synthesis and antitumor activity of novel pyrimidinyl pyrazole derivatives.

Novel pyrimidinyl pyrazole derivatives were synthesized and examined for cytotoxic and antitumor activity. Mannich reaction was employed to construct this scaffold. Among the compounds synthesized, a series of propene derivatives exhibited a potent cytotoxic activity against some tumor cell lines including multidrug resistant cell lines due to the overexpression of P-glycoprotein. The vinyl bond moiety in the scaffold was believed to be required for the cytotoxic activity. Among them, compound 14 g, when administered intraperitoneally, showed potent antitumor activity against the malignant ascites caused by intraperitoneal inoculation of P388 cells in mice. This compound also showed high activity against a solid tumor Meth A mouse fibrosarcoma when administered both intraperitoneally and orally.

Animals↗
PubMed1999

Transferability of cephalothin to the alveolar cavity in thoroughbreds.

Five Thoroughbreds were classified into 4 groups according to the administration method used for saline solution (saline), ambroxol, and cephalothin sodium (cephalothin). In group A, cephalothin was injected intravenously after oral administration of ambroxol. In group B, cephalothin was injected intravenously after oral administration of saline. Groups C and D were used as control groups. The dose of cephalothin or ambroxol was clinically administrated. Venous blood and bronchoalveolar lavage fluid (BALF) were sampled from each group. In groups A and B, cephalothin concentrations in plasma reached their maximum level 5 min after cephalothin administration and then declined over time. In plasma obtained from groups A and B, there were no significant differences in pharmacokinetic parameters (T1/2, Kel, Vd). By contrast, cephalothin concentrations in BALF reached their peak at 180 min after cephalothin administration in both groups A and B and maintained a relatively high level even after 300 min. These findings indicate that cephalothin requires a relatively long period of time to move from the blood stream to the alveolar cavity, but once transferred to the alveolar cavity, it is preserved for a long time. In groups A and B, cephalothin concentrations in BALF were approximately at the same level. However, in group A, total protein in BALF was lower at 60, 180, and 300 min than the other groups. Then, cephalothin concentration was adjusted to total protein in BALF. After adjustment to total protein in BALF, group A showed a concentration level of cephalothin approximately 1.5-fold higher than that of group B. This suggests that the transferability of cephalothin to the alveolar cavity improves as a result of the oral administration of ambroxol.

Ambroxol↗
PubMed1999

Regional left ventricular motion during early filling phase in patients with right ventricular pressure overload.

Global left ventricular (LV) diastolic function has been reported to be disturbed under conditions of right ventricular pressure overload (RVPO). However, from the standpoint of regional wall motion, only a little information related to the mechanism of LV diastolic dysfunction is available. Eight patients with RVPO and 7 healthy volunteers were investigated using tagged cine magnetic resonance imaging. Regional diastolic fraction (RDF) was determined in 4 segments (anterior, lateral, inferior, and septal) in the mid-ventricular short axis section and in 2 segments (septal and lateral) in the 4-chamber section. A heterogeneity index was obtained from the RDFs of the short axis section. In the RVPO group, in both short axis and 4-chamber sections, the RDF of the septal segment was depressed, and it showed an inverse correlation with the right-to-left ventricular systolic pressure (RV/LV) ratio (r = -0.74, p < 0.05) in the short axis section. In the 4-chamber section, the RDF was lower in the septal segment than in the lateral segment (p < 0.05). The heterogeneity index in the RVPO group was greater than that in the control group (p < 0.01). The index correlated positively with the RV/LV ratio (r = 0.77, p < 0.05). The altered regional diastolic motion results in increased heterogeneity in regional diastolic motion.

Adolescent↗
PubMed1999

Endotoxin contamination in isolation of lamina propria mononuclear cells.

Because the beginning of extraction of lamina propria mononuclear cells is to obtain mucosal tissues that are exposed to luminal bacteria, the contaminated endotoxin in this step and/or the enzymes for mucosal digestion may activate mucosal macrophages and other cells. To address this issue, endotoxin levels in isolation solutions were evaluated during the extraction of lamina propria mononuclear cells from 8 control, 7 Crohn's disease and 8 ulcerative colitis specimens. Endotoxin levels were measured using Toxicolor system based on the limulus tests. Endotoxin levels were consistently below 500 pg/ml, and more importantly, these in enzyme digestion solutions were comparable among control, Crohn's disease, and ulcerative colitis. Therefore, comparative experiments using lamina propria mononuclear cells from these mucosae can be appropriately carried out, at least as far as in a comparable amount of contaminated endotoxin. However, careful consideration is required for the comparative and functional study using peripheral blood and lamina propria mononuclear cells.

Aged↗
PubMed1999

Differential diagnosis of lymphocytic interstitial pneumonia and malignant lymphoma on high-resolution CT.

OBJECTIVE: Lymphoproliferative disorders span a spectrum from inflammatory lesions to malignant neoplasms. The purpose of this study was to compare high-resolution CT findings of lymphocytic interstitial pneumonia with those of malignant lymphoma of the chest. MATERIALS AND METHODS: The study included 17 patients with lymphocytic interstitial pneumonia and 44 patients with malignant lymphoma (35 with non-Hodgkin's lymphoma and nine with Hodgkin's disease). Without knowledge of the pathologic diagnosis, two chest radiologists evaluated the frequency and distribution of high-resolution CT findings in both groups of patients. RESULTS: Cysts were more common in patients with lymphocytic interstitial pneumonia (14/17, 82%) than in patients with malignant lymphoma (1/44, 2%) (p < .0001). Air-space consolidation was more commonly seen in patients with malignant lymphoma (29/44, 66%) than in patients with lymphocytic interstitial pneumonia (3/17, 18%) (p < .001). Large nodules (11-30 mm in diameter) were more common in patients with malignant lymphoma (41%) than in patients with lymphocytic interstitial pneumonia (6%). Pleural effusions (25%) were seen only in patients with malignant lymphoma. We found no statistically significant difference in the distribution of lung lesions between patients with lymphocytic interstitial pneumonia and patients with malignant lymphoma. CONCLUSION: On high-resolution CT, cysts are characteristic in patients with lymphocytic interstitial pneumonia, whereas consolidation, large nodules, and pleural effusions are characteristic in patients with malignant lymphoma. These findings on high-resolution CT help differentiate lymphocytic interstitial pneumonia from malignant lymphoma.

Adult↗
PubMed1999

A resected case of pancreatic metastasis from primary renal cell carcinoma.

A 71-year-old man, who had received a right nephrectomy for a primary renal cell carcinoma 8 years earlier, and had two years later received a distal gastrectomy for duodenal ulcer, was admitted. In the subsequent clinical course, a solitary low echographical tumor was found in the pancreas. Abdominal computed tomography revealed a tumor of low density area, and celiac angiography revealed a hypervascular tumor stain of the pancreas. From the above findings, a diagnosis of pancreatic tumor was made, and a distal pancreatectomy was performed. Examination of the resected tissues confirmed the presence of a solitary tumor in the pancreatic tail. Histologically, the tumor corresponded to the initial renal cell carcinoma and pancreatic metastasis of renal cell carcinoma was diagnosed. We report a resected case of such a metastasis and review the literature.

Aged↗
PubMed1999

[Usefulness of helical scanning CT in assessment of left ventricular papillary muscle contractility].

Three-dimensional data on the left ventricle at quasi-end-diastole and quasi-end-systole were acquired by helical scanning CT in 12 patients. Short axial images of the left ventricle and long axial images of the papillary muscle were created using multiplanar reconstruction. Left ventricular dimensions and the length of the papillary muscle were measured, and fractional shortening of the papillary muscle was calculated. There was a good correlation between left ventricular dimensions measured by echocardiogram and helical scanning CT (end-diastole: r = 0.94: end-systole: r = 0.86; fractional shortening of left ventricular dimension: r = 0.84). Papillary muscle fractional shortening was 6.3% in the ischemic group and 21.5% in the non-ischemic group (p < 0.005). Helical scanning CT is clinically useful for the assessment of left ventricular papillary muscle function.

Adult↗
PubMed1999

[Adverse effects of anti-thymocyte globulin/anti-lymphocyte globulin therapy].

This single-centre study evaluated the adverse effects of anti-thymocyte globulin (ATG) and anti-lymphocyte globulin (ALG) as used for the treatment of aplastic anemia and/or for conditioning regimens prior to stem cell transplantation. ATG/ALG was given to 29 patients a total of 37 times. The incidence of adverse effects was 62.1% (23/37), and fever was the most frequent adverse effect. Therapy was discontinued in only 4 patients (10.8%) due to severe adverse effects. Adverse effects occurred more frequently with ATG (rabbit-derived) than with ALG (horse-derived). Seven patients underwent 2 or 3 cycles of ATG/ALG therapy, for a combined total of 8 times; 6 of those patients (75% (6/8)) experienced adverse effects. Shorter intervals between repeated cycles of therapy appeared to heighten the risk of adverse reactions.

Adolescent↗
PubMed1999

[Re-coronary artery bypass grafting using a MIDCAB technique in a patient with a patent RITA-LAD graft].

In a patient with a patent RITA-LAD (right internal thoracic artery-left anterior descending artery) graft, re-CABG (re-coronary artery bypass grafting) with re-median sternotomy has been a high risk procedure. A 56-year-old male underwent 4-CABG (RITA-LAD, LITA-Dx, SVG-PL, and SVG-RCA) nine years ago. Coronary angiography showed that the RITA-LAD graft was well patent, but there was 95% stenosis distal to RITA-LAD anastomosis site. We performed re-CABG (right gastroepiploic artery-LAD; RGEA-LAD), using MIDCAB (minimally invasive direct coronary artery bypass) technique with neither re-median sternotomy nor cardiopulmonary bypass. The right gastroepiploic artery was harvested through a small upper median laparotomy and anastomosed to LAD through a small left anterior thoracotomy. The postoperative course was uneventful. This technique seems to be useful for re-revascularization of the LAD in a patient with a patent RITA-LAD graft.

Coronary Artery Bypass↗
PubMed1999

[Intra-arterial chemotherapy for invasive bladder cancer].

Between July 1993 and May 1999, 36 patients with invasive bladder cancer were treated with intra-arterial chemotherapy using cisplatin and pirarubicin, and their treatment outcome was evaluated. Clinical CR was obtained in 18 patients, PR in 13, and NC in 5, for an overall response rate of 86%. The median follow-up for evaluating patients was 24 months (2-70 months). The bladder was preserved in 13 of 18 patients showing CR and in 4 of 13 patients showing PR. The 5-year cause-specific survival rate for the 36 patients was 56%. The grade factor did not effect the survival rate significantly. Compared with stage T2, stage T3 yielded a significantly poor prognosis, especially with grade 3. Intra-arterial chemotherapy was confirmed useful as a regional treatment, but not sufficient as a systemic treatment. Thus the selection of patients for this therapy was considered to require exact staging and assessment of the effectiveness.

Adult↗
PubMed1999

The herbal medicine Dai-Kenchu-Tou stimulates upper gut motility through cholinergic and 5-hydroxytryptamine 3 receptors in conscious dogs.

BACKGROUND: The herbal medicine Dai-Kenchu-To, composed of zanthoxylum fruit, ginseng root, and dried ginger rhizome, is clinically effective for uncomplicated postoperative adhesive intestinal obstruction. We investigated the effect of Dai-Kenchu-To and each ingredient on upper gastrointestinal motility and its mechanism of action. METHODS: Five mongrel dogs were equipped with 4-strain gauge-force transducers on the gastric body, antrum, duodenum, and jejunum to measure contractile activity of the circular muscle. Dai-Kenchu-To (1.5 g) or the separate ingredients zanthoxylum fruit, ginseng root, or dried ginger rhizome (1.0 g each) were administered by bolus into the gastric lumen. The effect of atropine, hexamethonium, phentolamine, propranolol, and ondansetron on intragastric Dai-Kenchu-To-induced contractions was studied. RESULTS: Intragastric Dai-Kenchu-To induced phasic contractions in the antrum, duodenum, and jejunum. Zanthoxylum fruit elicited phasic contractions mainly in the duodenum and jejunum, whereas dried ginger rhizome induced phasic contractions in the antrum. Ginseng root had no effect. Phasic contractions induced by intragastric Dai-Kenchu-To were inhibited by atropine and hexamethonium at all sites, although ondansetron inhibited these contractions in the antrum and duodenum. CONCLUSIONS: Intragastric Dai-Kenchu-To stimulates upper gastrointestinal motility through cholinergic and 5-hydroxytryptamine 3 receptors.

Animals↗
PubMed1998

Functional characterization of the bovine conglutinin promoter: presence of a novel element for transcriptional regulation of a C-type mammalian lectin containing a collagen-like domain.

Bovine conglutinin is a Ca2+-dependent serum lectin that is specific for N-acetylglucosamine and a member of the collectin (collagen-like lectin) family. Here we report the identification of the cis-acting elements involved in regulating expression of the conglutinin gene. The 5'-flanking region of the conglutinin gene was cloned and sequenced by gene walking using vector (cassette)-ligation mediated PCR. A genomic fragment encompassing -741 to +50 bp had significant promoter activity when linked to the luciferase reporter gene and transfected into the human hepatoma cell line HepG2. Transfection analysis using a series of luciferase vector/5'-stepwise deletion mutants of the promoter constructs indicated that the sequence of 7 base pairs at around -180 bp from the transcription initiation site was necessary for the full expression of the conglutinin gene. The site-directed mutagenesis in the AP-1 (Activator Protein-1) sequence, immediately downstream of the positively controlling cis-element at around -180 bp, resulted in a marked loss of the promoter activity. The novel positively controlling cis-element and the AP-1 sequence regulated synergistically the expression of the conglutinin gene. Gel retardation assay and DNase I footprint analysis demonstrated the presence of the nuclear proteins that bind to these two cis-elements.

Animals↗
PubMed1998

Left ventricular regional systolic motion in patients with right ventricular pressure overload.

Left ventricular regional systolic motion was investigated in patients with right ventricular pressure overload and 10 controls using tagged cine magnetic resonance imaging. The regional shortening fraction was determined in four segments (septal, lateral, inferior, and anterior) on the short-axis image. An asynchrony index, nonhomogeneity of regional shortening, was calculated. Septal shortening in these patients was depressed, and showed an inverse correlation with the right-to-left ventricular peak pressure ratio (r=-0.80, P<0.01). Lateral shortening was greater in the patients than in the controls (P<0.01). The asynchrony index was significantly greater in the patients than in the controls (P<0.01), and correlated with the right-to-left systolic pressure ratio (r=0.64, P=0.02) and the left ventricular end-diastolic pressure (r=0.79, P<0.01). The altered distribution of regional circumferential shortening results in an increased heterogeneity of regional systolic motion. These findings may have important implications for the assessment of ventricular function in patients with right ventricular pressure overload.

Adult↗
PubMed1998

Different ras gene mutational frequencies in thyroid papillary carcinomas in Japan and Thailand.

The incidence and pattern of ras oncogene mutations in human malignancies demonstrate geographic and racial differences. For example, specificity of alterations is found in cholangiocellular carcinomas in Thai patients with a different etiology from those in Japanese patients. In the present study, a comparison of ras gene mutations in thyroid papillary carcinomas from Japanese and Thai patients was performed using single-strand conformation polymorphism and direct sequencing analyses. The incidence of ras mutation differed markedly in Japanese (two of 24 carcinomas, 8.3%) and Thai (five of 10 carcinomas, 50%) patients. In addition, all but one ras mutation occurred at codon 12 of the K-ras gene in the Thai cases. These results suggest that thyroid cancers in Thailand may be due to specific genetic and/or environmental factors.

Adult↗