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Biomedical subjects

H Minami

Publications and source records attributed to H Minami.

At least 37 records · Page 2Linked to original sources
PubMed1994

Different effects of antidepressants on dissociation of 3H-imipramine from solubilized binding sites of rat brain.

1. The effects of several antidepressants and 5-hydroxytryptamine on dissociation of 3H-imipramine from solubilized binding sites were investigated. 2. Binding sites were solubilized from rat brain membranes and gelfiltrated on a column of Sephacryl S-300. 3. Most of the agents used allowed biphasic dissociation with 1mM of displacing agent and without using dilution-induced dissociation. This biphasic dissociation without nonspecific effects of membranes may be due to the existence of low-affinity binding sites. 4. Dissociation of up to 40 min followed first-order kinetics. The dissociation half-life of 3H-imipramine with the various displacing agents was calculated at from 15.0 to 25.0 min, and the differences among the agents were not so significant as the attenuation or the acceleration of the dissociation was indicated. The lower concentration of the displacing agents may obscure the modulation of the dissociation.

Animals↗
PubMed1994

Severe neurological abnormalities associated with a mutation in the zinc-finger domain in a group A xeroderma pigmentosum patient.

All the reported Japanese patients with group A xeroderma pigmentosum (XP) have two or three mutations at codon 116 in exon 3, codon 228 in exon 6, and the splicing acceptor site of intron 3 of XP group A complementing (XPAC) gene. A homozygote (XP39OS) with a nonsense mutation at codon 228 has less severe neurological abnormalities than patients with the splicing mutation at the acceptor site of intron 3. As homozygotes for the nonsense mutation at codon 116, which truncates a carboxyl-terminal site of XPAC protein at an early part of its zinc-finger domain, have not been reported previously, the possible severity of associated neurological abnormalities was not known. We report a group A XP patient, XP18OS, who had neurological abnormalities which were more severe than those in patients homozygous for the splicing mutation. The polymerase chain reaction product from exon 3 of the patient's XPAC gene was digested completely into three fragments by MseI restriction endonuclease. Thus, the patient was homozygous for the mutation at codon 116.

Base Sequence↗
PubMed1994

Endobronchial mucosal bridges as evidence of residual malignancy.

Three patients who exhibited endobronchial mucosal bridges that formed at the site of tumor regression following chemotherapy for small cell lung carcinoma are presented. Histopathologic examination showed residual malignant cells in 2 of the 3 patients within the submucosal fibrous tissue and an overlying benign epithelium. Although these mucosal bridges were previously thought to represent a complete remission following chemotherapy or radiotherapy for small cell lung carcinoma, they may, in fact, harbor a residual malignancy under the benign mucosa.

Aged↗
PubMed1994

Interbronchoscopist variability in the diagnosis of lung cancer by flexible bronchoscopy.

STUDY OBJECTIVE: We evaluated the interbronchoscopist variability in the diagnosis of lung cancer by flexible bronchoscopy. DESIGN AND SETTING: A retrospective review of the bronchoscopic records and clinical charts of patients at a university-affiliated hospital. PATIENTS AND MEASUREMENTS: All records of flexible bronchoscopic procedures performed for the diagnosis of lung cancer were retrospectively reviewed, and procedures that obtained histologic or cytologic evidence of malignancy were considered positive. Rates of positivity were compared according to the following factors: operator, operator experience, bronchoscopic findings, tumor location, and tumor laterality. Factors that affected the positivity rate were evaluated using logistic regression analysis. RESULTS: Of 384 bronchoscopic procedures performed in 353 patients, 275 (72 percent) were positive. The positivity rate differed significantly depending on the operator (p = 0.003) and the bronchoscopic findings (p < 0.001). A difference between operators was noted in technically difficult cases without epithelial or subepithelial findings and when tumors were located in the upper lobe or the superior segment of the lower lobe. The bronchoscopic findings and the operator also emerged as factors significantly affecting the positivity rate in the logistic analysis. CONCLUSIONS: The diagnostic yield of bronchoscopy for lung cancer is dependent on both the type of bronchial lesion present and the bronchoscopist.

Bronchoscopy↗
PubMed1994

Rupture of thoracic aorta caused by penetrating aortic ulcer.

We present the findings in a 57-year-old man with a rupture of the thoracic aorta that originated in a penetrating atherosclerotic aortic ulcer. It formed a large hematoma that clinically mimicked a true saccular thoracic aneurysm. The possibility of penetrating aortic ulcer should be considered in the differential diagnosis of aortic aneurysm.

Aortic Aneurysm, Thoracic↗
PubMed1994

[Clinical evaluation of intracavernous self-injection of vasoactive drugs for impotence: a long-term follow-up observation].

From December 1989 to September 1992, nine patients with impotence were instructed to perform intracavernous self-injection of vasoactive drugs. At first 40 mg of papaverine hydrochloride was used in all patients and the response on erection was evaluated. If the response did not show sufficiently functional erection, a mixture of 40 mg of papaverine hydrochloride and 1 mg of phentolamine mesylate or 20 mg of prostaglandin E1 was reinjected. Eight patients had achieved full erections and vaginal penetrations without noteworthy complications during the follow-up period. Out of eight patients, three patients were able to ejaculate and one patient showed recovery of erection. No major side effects were seen. In conclusion, intracavernous self-injection is a useful modality for impotence.

Adult↗
PubMed1994

[A case of mediastinal mature teratoma presenting increased serum CA19-9 level].

A case of mediastinal mature teratoma with elevated serum CA19-9 level is reported. A 50-year-old woman admitted to our hospital complaining of cough and chest pain. Chest X-ray showed an abnormal mass shadow with retention of the right pleural effusion. Her serum CA19-9 level was high (204.4 U/ml), while serum AFP, CEA, HCG levels were normal. On lateral thoracotomy, an anterior mediastinal tumor perforating into the right lung was revealed and the total resection of the tumor with adherent part of the right lung was performed. Postoperatively, her serum CA19-9 level returned to normal. Histological examination disclosed a mature teratoma consisting of skin, pancreatic tissue, cartilage, bronchial epithelium, etc. Immunohistochemical staining were positive in the bronchial epithelium and bronchial gland but was negative in the pancreatic tissue of the tumor. This is a rare case of mediastinal mature teratoma with elevated serum CA19-9 level and negative immunohistochemical staining for it in the pancreatic tissue of the tumor.

CA-19-9 Antigen↗
PubMed1993

Expression of active human DNA ligase I in Escherichia coli cells that harbor a full-length DNA ligase I cDNA construct.

A recombinant plasmid for expression of full-length human DNA ligase I (phLig-I) was constructed in a plasmid/phage chimeric vector, pTD-T7N, which was derived from pUC118 by oligonucleotide-directed mutagenesis. The insert contained a 2757-base pair coding sequence for a whole human DNA ligase I and an extra ACC codon adjacent to the ATG initiation codon. This ACC codon was required for achieving high levels of expression of full-length DNA ligase I in Escherichia coli strain BL21. The recombinant plasmid, which was designed to exploit the T7 late promoter and the ATG initiation codon for beta-galactosidase was transfected into E. coli BL21 cells that express T7 RNA polymerase. The recombinant clone produced relatively high levels of DNA ligase I with a molecular mass of 130 kDa, as estimated by SDS-polyacrylamide gel electrophoresis. The DNA ligase was purified to near-homogeneity by the two-step column chromatographic procedure from BLphLig-I cells that had been induced with isopropyl beta-D-thiogalactoside. The specific activity, chromatographic behavior, kinetic properties, molecular mass, and antigenicity of the recombinant human DNA ligase I were indistinguishable from those of purified mammalian DNA ligase I. Metabolically labeling experiments with 32P(i) indicate that the recombinant DNA ligase I was present as an enzyme-AMP reaction intermediate, but not as a phosphoprotein, in the E. coli cells.

Amino Acid Sequence↗
PubMed1993

Differential responses of intestinal glucose transporter mRNA transcripts to levels of dietary sugars.

Dietary sugars are known to stimulate intestinal glucose transport activity, but the specific signals involved are unknown. The Na(+)-dependent glucose co-transporter (SGLT1), the liver-type facilitative glucose transporter (GLUT2) and the intestinal-type facilitative glucose transporter (GLUT5) are all expressed in rat jejunum [Miyamoto, Hase, Taketani, Minami, Oka, Nakabou and Hagihira (1991) Biochem. Biophys. Res. Commun. 181, 1110-1117]. In the present study we have investigated the effects of dietary sugars on these glucose transporter genes. A high-glucose diet stimulated glucose transport activity and increased the levels of SGLT1 and GLUT2 mRNAs in rat jejunum. 3-O-Methylglucose, D-galactose, D-fructose, D-mannose and D-xylose can mimic the regulatory effect of glucose on the SGLT1 mRNA level in rat jejunum. However, only D-galactose and D-fructose increased the levels of GLUT2 mRNA. The GLUT5 mRNA level was increased significantly only by D-fructose. Our results suggest that the increase in intestinal transport activity in rats caused by dietary glucose is due to an increase in the levels of SGLT1 and GLUT2 mRNAs, and that these increases in mRNA may be caused by an enhancement of the transcriptional rate. Furthermore, for expression of the SGLT1 gene, the signal need not be a metabolizable or transportable substrate whereas, for expression of the GLUT2 gene, metabolism of the substrate in the liver may be necessary for signalling. Only D-fructose is an effective signal for expression of the GLUT5 gene.

Animals↗
PubMed1993

Calvasculin, as a factor affecting the microfilament assemblies in rat fibroblasts transfected by src gene.

Cell transformations accompany alterations in cell morphology and microfilament patterns. Calvasculin encodes mRNA termed pEL-98, 18A2, 42A, p9Ka, or mts1, found to be elevated in several metastatic cell lines. We report the elevation of calvasculin expression in SR-3Y1 cells, which show disappearance of ordered microfilaments, compared to that in 3Y1 cells and that the similar distribution of calvasculin to that of actin filaments. Interestingly, calvasculin co-sediments with F-actin and bundles actin filaments in a Ca(2+)-dependent manner. This activity, along with the elevation of calvasculin following transformation, suggests that the disorganization of filaments in SR-3Y1 cell is due to the cross-linking activity of calvasculin.

Actin Cytoskeleton↗
PubMed1993

Na+/D-glucose cotransporter based bilayer lipid membrane sensor for D-glucose.

A new type of amperometric blosensor for glucose was fabricated using a Na+/D-glucose cotransporter as the signal-transducing sensory element that exploits the D-glucose-triggered Na+ ion current through bilayer lipid membranes (BLMs). The planar BLM was formed by the folding method across a small aperture of a thin Teflon film. The Na+/D-glucose cotransporter, isolated and purified from small intestinal brush border membrane of guinea pigs, was embedded into BLMs through proteoliposomes. The number of the protein molecules thus incorporated in the present sensing membrane was estimated to be ca. 10(7). The sensor response was measured as an ionic current through the BLM arising from cotransported Na+ ion flux under a constant applied potential and was only induced by D-glucose above 10(-9) M, but not by the other monosaccharides except for D-galactose. The effect of applied potentials, Na+ and K+ ion concentrations, and the addition of a competitive inhibitor, phlorizin, were scrutinized to characterize the sensor output. The results were briefly discussed in terms of the potential use of the Na+/D-glucose cotransporter as a sensory element for D-glucose.

Animals↗
PubMed1993

Inhibition of glucose absorption by phlorizin affects intestinal functions in rats.

BACKGROUND: To investigate the mechanism of regulation of intestinal disaccharidase activity and glucose absorption, the effect of dietary intake of phlorizin, a potent and specific inhibitor of intestinal glucose transport, on intestinal disaccharidase activity and Na(+)-dependent glucose transporter was examined in rats. METHODS: Jejunal disaccharidase activity and the number of Na(+)-dependent glucose transporters were determined in rats maintained on a low-starch diet, a high-starch diet, or low-starch diets containing various amounts of phlorizin (0.1%-0.9% wt/wt). RESULTS: Jejunal disaccharidase activity increased in a dose- and time-dependent manner. Stimulation of jejunal disaccharidase activity only occurred when phlorizin was added to starch-containing diets, not when it was added to a carbohydrate-free diet. Addition of the same amount of phloretin and glucose (constituents of phlorizin), to the diet failed to increase disaccharidase activity. The maximum binding of phlorizin to brush border membrane vesicles was increased in the rats fed phlorizin, whereas the dissociation constant remained unchanged, suggesting an increase of glucose transporter expression. CONCLUSIONS: Dietary phlorizin increased the jejunal disaccharidase activity and Na(+)-dependent glucose transporter expression. The trigger for these changes may have been due to an increased luminal glucose content.

Administration, Oral↗
PubMed1993

Phase I clinical and pharmacokinetic study of a 14-day infusion of etoposide in patients with lung cancer.

PURPOSE: A phase I study was conducted to determine the maximum-tolerated dose (MTD) of a 14-day continuous infusion of etoposide, and to evaluate the pharmacokinetics in patients with lung cancer. PATIENTS AND METHODS: Etoposide was administered continuously through a central venous catheter using a pump. The starting dose level was 300 mg/m2 over 14 days, with dose escalations of 100 mg/m2 over 14 days until unacceptable toxicities occurred. Pharmacokinetic studies were performed in all patients. RESULTS: Twenty-one patients, 20 with non-small-cell lung cancer and one with refractory small-cell lung cancer, received 37 courses. No World Health Organization (WHO) grade III or greater toxicity occurred at doses up to 400 mg/m2 over 14 days. At 700 mg/m2 over 14 days, all four patients experienced grade III or IV leukocytopenia, and two developed grade III stomatitis. No cumulative toxicity was observed. A steady concentration of etoposide was achieved 24 hours after the start of chemotherapy, and it was significantly correlated with surviving fractions of leukocytes (r = -.64, P = .001) and platelets (r = -.68, P < .001). The leukocyte count at the termination of chemotherapy predicted the nadir count (r = .93, P < .001). CONCLUSION: Steady blood levels of etoposide were maintained for prolonged periods, during 14-day continuous infusions. Leukocytopenia and stomatitis were dose-limiting. Nadir counts and surviving fractions of leukocytes were predicted by the leukocyte count at the end of chemotherapy and the concentration of etoposide, respectively. The recommended dose for phase II trials is 600 mg/m2 over 14 days.

Adult↗
PubMed1993

[Analysis by two-dimensional electrophoresis of the cause of myocardial dysfunction in aging rat hearts].

The severity and frequency of atherosclerosis, diabetes, and ischemic heart disease, which affect cardiac function, increase with aging. Although there are many reports about hemodynamic and histopathological studies about aging hearts, there are very few studies on changes in structural proteins in aging hearts. We investigated the contractile proteins of the left ventricles in rats aged 6, 12 and 125 weeks using two-dimensional electrophoresis. There were no difference in structural proteins in heart between 6-week and 12-week-old rats. The contents of myosin heavy chain, myosin light chain 2, actin, troponin-I in 125-week-old rats decreased compared with those of 12-week-old rats. Myosin heavy chain, which is one component of myosin, interacts with actin and changes chemical energy to mechanical energy. Therefore its decrease leads to a decline in myocardial contractility. These results seem to indicate one of the most important changes in the aging rat heart, as well as impairment in relaxation by the increase of interstitial fibrosis and decline of Ca uptake by sarcoplasmic reticulum.

Aging↗
PubMed1993

Immunohistochemical analysis of keratin distribution in eccrine poroma.

Although eccrine poroma has been thought of as a neoplasm of the intradermal eccrine duct, this interpretation has not been entirely confirmed. In this study, twenty-five cases of eccrine poroma were retrieved and analyzed by immunohistochemical techniques, using various kinds of monoclonal antikeratin antibodies. Comparative immunohistochemical observations of eccrine poroma and normal eccrine glands revealed that the poroma cells expressed immunophenotypes similar to those of the basal cells of dermal eccrine ducts. Sweat-ductlike structures showed similar staining patterns to those observed in the inner cells of dermal eccrine ducts. Some cystic spaces were similar to those observed in the secretory cells of eccrine glands. Eccrine poroma is, therefore, speculated to originate via the proliferation and expansion of the basal cells of eccrine ducts, although it is very difficult to prove the histogenesis. Some tumor cells may differentiate toward inner cells of the eccrine ducts, forming ductal lumina, whereas other tumor cells differentiate toward eccrine secretory regions, forming some cystic spaces.

Adenoma, Sweat Gland↗