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Biomedical subjects

K Nonaka

Publications and source records attributed to K Nonaka.

At least 127 records · Page 7Linked to original sources
PubMed1995

Vascularized omental graft to brain surface in ischemic cerebrovascular disease.

The application of vascularized omental graft for the treatment of four patients with ischemic cerebrovascular disease is presented. The superficial temporal artery and vein were used as recipient vessels, and vascular anastomosis was applied in an end-to-end fashion. The distal parts of the omentum were exteriorized as monitoring segments for about 1 week. Angiography and cerebral blood flow (CBF) studies were performed in all patients postoperatively. There were no major complications, and all patients showed increases of CBF and apparent clinical improvement. It is suggested that this method is effective in selected patients with ischemic cerebrovascular disease.

Brain↗
PubMed1995

Effect of the dam strain on the spontaneous incidence of cleft lip and palate and intrauterine growth of CL/Fr mouse fetuses.

PURPOSE: The effects of dam strain on the spontaneous incidence of the cleft lip and palate (CLP) and the intrauterine growth of transferred CLP-susceptible CL/Fr embryos were examined with an embryo transfer technique. The CL/Fr strain of embryos at the early blastocyst stage was transferred to the same dam strain and also to the CLP-resistant C57BL dam strain. A laparotomy was done on the 18th gestational day at which time the number of fetuses, the resorption sites and the fetus weight were recorded. Each fetus was checked for the presence of CLP. Five criteria to assess the reproduction and fertility as well as the fetus weight were then compared between both dam strains. RESULTS: The dam pregnancy rate and the fetus survival rate in the CL/Fr dam strain were both significantly lower than those in the C57BL dam strain. The resorption rate in the CL/Fr dam strain was significantly higher than that in the C57BL dam strain. The spontaneous incidence rate of CLP in the CL/Fr dam strain was also significantly higher than that in the C57BL dam strain. The fetus weight of the CL/Fr fetuses developed in the CL/Fr dam strain was significantly lighter than that of the CL/Fr fetuses developed in the C57BL dam strain. CONCLUSION: The results indicated that the CLP-susceptible CL/Fr dam strain provided a less favorable uterine environment for the implantation, survival and intrauterine growth of the transferred CL/Fr embryos and also caused a higher spontaneous incidence rate of CLP. Thus, it can be concluded that the effect of the dam strain appears to play an important role on the spontaneous incidence of CLP and the intrauterine growth of the CL/Fr strain embryos transferred to both CL/Fr and C57BL dam strains.

Animals↗
PubMed1995

Poly(ADP-ribose) synthesis induced by nitric oxide in a mouse beta-cell line.

Nitric oxide (NO) has been implicated as an immunological effector molecule that mediates beta-cell dysfunction associated with Type 1 diabetes. To assess whether NO induces poly(ADP-ribose) synthesis in islet cells, we examined the effect of nitroprusside on islet cells. The exposure of mouse islet cells and a beta-cell line (beta TC1) to 0.05-0.2 mM nitroprusside resulted in the reduction of intracellular nicotinamide adenine dinucleotide (NAD) levels. Nitroprusside stimulated poly(ADP-ribose) synthetase activity in beta TC1 cells. An inhibitor of poly(ADP-ribose) synthetase, 3-aminobenzamide, prevented both NAD decrease and poly ADP-ribosylation. These observations suggest that NO-induced pancreatic beta-cell damage may be ascribable to the activation of poly(ADP-ribose) synthetase that results in the decrease of NAD content.

Animals↗
PubMed1995

Slow twin conception at first birth and subsequent maternal twin proneness in a natural fertility population.

To study whether apparently more fecund women having delivered twins at first birth have traits of higher twin-proneness, we performed a retrospective cohort study on population-based historical vital records of the 17-18th century French Canadian immigrants and their descendants under natural fertility conditions. Among 24896 mothers who had at least one child, 248 had twin maternities at their first birth (twinning rate = 1.0%). Among 21508 mothers with a valid marriage-first birth interval, twinning rate was 0.97% among prompt conceptions (7.0-11.0 months), with a particularly high rate at the interval of 7.0-8.0 months (2.2%). Marriages in August-October resulted in a higher twinning rate particularly for the slow conceptions than those in the other seasons. Promptly-conceived mothers of twins at the first delivery may seem to have higher fecundity, but subsequent births from these mothers (n = 88) show a lower twinning rate (1.7%) particularly at younger maternal age than from the other mothers who had slowly conceived twins at their first birth (n = 112). The latter show a 4.5% twinning rate as a whole among their second or later births. So-called twin-proneness of a mother, whether genetic or acquired, was not connected to higher conception rate of twin's mothers immediately after marriage. Reduced fecundity, which may have been imposed by some environmental factors, could raise the chance of twinning.

Adult↗
PubMed1995

Human histocompatibility leukocyte antigen-DR and heat shock protein-70 expression in eye muscle tissue in thyroid-associated ophthalmopathy.

To investigate the expression and localization of human leukocyte antigen (HLA)-DR and heat shock protein-70 (HSP-70) in orbital tissue from patients with thyroid-associated ophthalmopathy (TAO), we carried out an immunohistochemical study using anti-HLA-DR and anti-HSP-70 monoclonal antibodies and a streptavidin-biotinperoxidase detection system. Eye muscle tissues were obtained at surgery from 38 patients with TAO and 8 control subjects. HLA-DR expression on eye muscle cells was demonstrated in orbital tissue from 2 of 3 untreated patients and 2 of 35 patients who had been treated with orbital irradiation or corticosteroids, in all of whom lymphocytic infiltration was also demonstrated. HLA-DR was not detected on eye muscle cells from 8 normal controls studied. HLA-DR was expressed on endothelial cells and interstitial cells from almost all patients with TAO and all 8 control subjects. HSP-70 was detected in eye muscle cells from 31 of the patients with TAO, including all 3 untreated patients, and 3 of the controls. Although the degree of HSP-70 expression did not correlate with the severity of the ophthalmopathy, significant expression of HSP-70 in eye muscle cells was more often demonstrated in patients with eye disease of short duration (83%) than in those with disease of longer duration (33%). These results support the notion that eye muscle fiber is an important target of the orbital autoimmune reactions that characterize TAO.

Adult↗
PubMed1995

Chitosan-derived polymer-surfactants and their micellar properties.

Chitosan derivatives, sulfated N-acyl-chitosan (S-Cn-chitosan) possessing various lengths of alkyl chain, were prepared, and the properties of their aqueous solutions were examined. The 1H-NMR spectrum of D2O solutions of S-C12-chitosan showed broadening of the proton signals caused by aggregation of the alkyl chain. The solubility of a hydrophobic compounds, azobenzene, was small in the aqueous solutions of S-Cn-chitosan with shorter alkyl chains, but increased with increasing length of the chains above C10, showing that micelles had been formed. The ESR spectrum of a spin probe, TEMPO, in an S-C14-chitosan solution showed the existence of a hydrophobic region in the solution, but this region did not exist in the S-C2-chitosan solution. The rigidity of this region was examined by using a spin probe, 16-doxyl-stearic acid. From these results, it was revealed that S-Cn-chitosan with longer alkyl chains formed a novel type of micelle called a "polymer micelle," which was more stable than the ordinary micelles formed from low-molecular-weight surfactants.

Acylation↗
PubMed1995

[Operative removal of esophageal leiomyosarcoma: a case report].

This is a case report of 56-year-old man complaining of dysphasia. Upon admission, his chest X-ray film revealed medium amount of fluid accumulation in the right pleural space. Cytological examination of the aspirated fluid revealed nothing particular. Preoperative radiological examination including esophagogram, CT and MRI demonstrated cystic appearance of mass lesion, measuring approximately 5 cm in size located in posterior aspect of the lower portion of the mediastinum. Upon operation, it was found that a tumor with pedunculated connection to the esophageal muscle layer, suspecting diagnosis of leiomyoma of the esophagus. Then, tumor was removed together with the part of esophageal muscle. Postoperative pathology reported leiomyosarcoma of the esophagus with low grade malignancy. We added no esophagectomy. He made uneventful recovery without no sign of recurrence of the malignancy, 4 years after the surgery.

Esophageal Neoplasms↗
PubMed1995

Effects of a new calcium channel blocker, MPC-1304, on blood pressure, serum lipoproteins and serum carbohydrate metabolism in patients with essential hypertension.

The effects of MPC-1304, a new calcium channel blocker, on blood pressure, serum lipoproteins, and carbohydrate metabolism were compared with those of atenolol in a group of patients with mild to moderate essential hypertension. Systolic and diastolic pressures were significantly decreased by both MPC-1304 and atenolol administration. Serum levels of apolipoproteins A-I and A-II were significantly increased after 8-12 weeks of MPC-1304 treatment, but were unchanged during a similar period of atenolol treatment. Neither drug induced any significant change in other lipoprotein parameters, fasting blood sugar, immunoreactive insulin, C-peptide or HbA1c. No serious side-effects or abnormal laboratory values were observed during the course of administration of either drug. These findings indicated that MPC-1304 is as efficacious as an antihypertensive drug and is without adverse effect on lipoprotein or carbohydrate metabolism.

Adult↗
PubMed1995

[Aortic aneurysm complicated with coarctation of the aorta and Turner syndrome].

A 23-year-old female with Turner syndrome and horse-shoe kidney underwent the operation of the coarctation of the aorta associated with the thoracic aortic aneurysm. The aortic aneurysm was located between the left carotid artery and the coarctation of the aorta, and the subclavian artery which was branched away from the aortic aneurysm was also aneurysmal. Aneurysmectomies and the reconstruction of the descending thoracic aorta and the left subclavian artery were performed with knitted Dacron grafts under assisting of the left atriodescending thoracic aortic bypass with Bio-pump. The disease was rare and such a case was not reported previously.

Adult↗
PubMed1995

Effect of the new nitrate ester ITF 296 on coronary and systemic hemodynamics in the conscious dog: comparison with nitroglycerin and nicorandil.

The coronary and systemic hemodynamic effects of the novel nitrate ester ITF 296 were investigated in conscious, resting dogs and compared with nitroglycerin and nicorandil. ITF 296 at 1-25 micrograms/kg i.v. elicited selective, long-lasting, and dose-dependent increases in large epicardial coronary artery diameter (CD) without affecting coronary blood flow (CBF) or coronary vascular resistance (CVR). Blood pressure (BP) and heart rate (HR) were also unaltered. At 125 micrograms/kg, ITF 296 further increased CD but simultaneously reduced CVR and mean aortic pressure and increased CBF and HR. Nitroglycerin 1-25 micrograms/kg induced a shorter and less selective dilatation of large coronary conductance arteries, as it was accompanied by a decrease in CVR at all doses used. Nicorandil produced a selective increase in left circumflex CD only at the lowest dose used (10 micrograms/kg), whereas higher doses were effective on both CD and CVR. ITF 296 significantly reduced left ventricular end-diastolic pressure and increased stroke volume (SV) and cardiac output (CO) at doses that did not alter HR or BP, indicating an increase in cardiac efficiency. In contrast, the increases in CO produced by nitroglycerin and nicorandil were dependent on the augmentation of HR, because SV was unchanged at all doses used. Nitroglycerin dose-dependently decreased BP, whereas ITF 296 reduced BP only at the highest dose used. In conclusion, ITF 296 induces a selective, flow-independent dilatation of large coronary conductance arteries without affecting the tone of small coronary resistance vessels or systemic hemodynamics over a broad range of doses. An equally selective effect was elicited by nicorandil only at the lower dose used, whereas no selective effect of nitroglycerin on the diameter of coronary conductance arteries was seen at the doses utilized in this study.

Animals↗
PubMed1994

Experimental quantitative evaluation of transvascular removal of unnecessary substances in brain edema fluid.

We developed a model by which the transvascular removal of unnecessary substances in brain edema fluid could be measured quantitatively and chronologically. Brain stab wounds were produced in Wistar rats by insertion of paired microdialysis probes in the unilateral caudatoputamen. Homovanillic acid (HVA) was administered by microdialysis from one probe, and the HVA clearance was measured by HPLC analysis of perfusate from the other probe. Using this model, we evaluated the site of removal and whether the removal processes were affected by anesthesia or an elevated plasma concentration of the substance. As a result, 1) Probenecid did not change HVA clearance although this inhibits HVA removal via subarachnoid vessels. Therefore, HVA removal in this model was considered mainly due to intraparenchymal transvascular efflux. 2) There was no alteration in HVA removal induced by anesthesia or intravenous HVA injection. Consequently, this efflux mechanism seems to be a rather stable protective process, and seems to play a considerable role in brain microenvironmental homeostasis.

Animals↗
PubMed1994

The effect of dam's strain on the intrauterine craniofacial growth of mouse fetuses.

PURPOSE: The maternal effect is one of the important factors in mammalian growth in conjunction with the genetic effect. The present study investigated the prenatal maternal effect of a dam on the intrauterine craniofacial growth of a mouse fetus using embryo transfer and cephalometry. DDD/Qdj strain mouse embryos were transferred to four strains of recipient female mice (DDD/Qdj, C3H/Qdj, C57BL/Qdj, and DBA/1J Sea). Just after parturition cephalometric observation of the newborn offspring, which developed in the uteri of the four strains of dams, was performed and then the craniofacial size of the newborn offspring was calculated on the lateral cephalogram. Statistical analyses were performed to examine the correlation between the dam's weight and the craniofacial size of the newborn offspring, to test the significance of the effect of the dam's strain on the craniofacial size of the newborn offspring, and to evaluate the interstrain difference of the intrauterine craniofacial growth of the mouse fetuses. RESULTS: It was disclosed that there were a direct relation between the dam's weight and the craniofacial size of the newborn offspring, a significant effect of the dam's strain on the craniofacial size of the newborn offspring, and a significant interstrain difference in the craniofacial size of the newborn offspring after eliminating the effects of litter size and gestation period on the craniofacial size of the newborn offspring (DDD/Qdj > C3H/Qdj = C57BL/Qdj > DBA/1J Sea). CONCLUSION: Thus, it could be concluded that the four strains of dams affected differently the intrauterine craniofacial growth of the DDD/Qdj strain fetuses through each uterine condition, indicating that the dam's weight played an important role as one of the prenatal maternal effects on the intrauterine craniofacial growth of mouse fetuses.

Animals↗
PubMed1994

Localization of heat shock protein in orbital tissue from patients with Graves' ophthalmopathy using in situ hybridization.

We studied the cellular localization of heat shock protein 70 (HSP70) synthesis in human orbital tissue from patients with Graves' ophthalmopathy(GO) before and after immunosuppressive therapy. Synthesis was detected using in situ hybridization techniques. In a specimen from a GO patient in active phase, strong expression of HSP70 mRNA was detected in infiltrating lymphocytes as well as in fibroblasts. HSP70 mRNA was also detected in orbital tissue fibroblasts from GO patients following treatment, but not in control specimens. HSP70 expression in the orbital tissue of GO patients may be important in mediation of the immune process.

Adult↗
PubMed1994

Elevated adenosine deaminase activity in the serum of patients with diabetes mellitus.

Adenosine deaminase (ADA) is suggested to be an important enzyme for modulating the bioactivity of insulin, but its clinical significance in diabetes mellitus (DM) is not yet characterized. We measured the serum levels of ADA isoenzymes (ADA1 and ADA2) in healthy donors (HD, n = 52), insulin-dependent diabetes mellitus (IDDM, n = 53) patients and non-insulin-dependent diabetes mellitus (NIDDM, n = 65) patients. The mean serum level of ADA1 in HD, IDDM or NIDDM patients was, respectively 6.5, 8.1 or 9.5 units/l (P < 0.001 vs. HD) and that of ADA2 in HD, IDDM or NIDDM patients was 7.0, 14.9 (P < 0.001 vs. HD) or 11.2 units/l (P < 0.001 vs. HD), respectively. Normalization of the blood glucose level by the hospitalization was associated with the decrease in ADA2 (but not ADA1) activity in 6 of 8 IDDM or 11 of 12 NIDDM poorly controlled patients. ADA2 (but not ADA1) activity in the poorly controlled NIDDM patients directly correlated with the hemoglobin A1c level (P < 0.002). Measurement of serum ADA2 activity may be important to better understand the clinical aspects of both IDDM and NIDDM. The pathogenic role of elevated ADA activity in the sera of DM patients was addressed.

Adenosine Deaminase↗
PubMed1994

Comparative effects of monatepil, a novel calcium antagonist with alpha 1-adrenergic-blocking activity, and nitrendipine on lipoprotein and carbohydrate metabolism in patients with hypertension.

The effects of monatepil, a new calcium antagonist with alpha 1-blocking activity, and nitrendipine on lipoprotein and carbohydrate metabolism in 86 patients with mild-to-moderate hypertension were examined in a randomized, open-label, multicenter (32 hospitals) study. Thirty-nine patients treated with monatepil and 33 patients treated with nitrendipine completed the 12-week study. Monatepil and nitrendipine each significantly decreased both systolic and diastolic blood pressure. Changes in heart rate were not seen in either group. Monatepil administration significantly decreased total cholesterol, low density lipoprotein (LDL) cholesterol, the LDL cholesterol to high density lipoprotein (HDL) cholesterol ratio, apolipoprotein (Apo) B levels, and HbA1c levels, whereas no changes in these measurements were observed in nitrendipine-treated patients. Monatepil also significantly decreased lipoprotein(a) levels, but there were no significant changes in HDL cholesterol, Apo-AI, or Apo-E levels. After nitrendipine treatment, the C peptide concentration decreased significantly, although no significant changes were observed in fasting blood glucose or immunoreactive insulin levels. On the basis of these results, it can be concluded that monatepil belongs to a new class of antihypertensive calcium antagonist with favorable carbohydrate metabolism and lipid-lowering activity, although the clinical importance of these findings has not been established.

Adrenergic alpha-Antagonists↗
PubMed1994

Genetic variation in experimental dental caries in four inbred strains of rats.

The relative contribution of the host genetic effect on the susceptibility to dental caries was examined. Four inbred strains of male rats (BN/Sea, F344/Ms, PVG/cSea, and WKA/Sea) were inoculated with Streptococcus mutans and fed a cariogenic diet. The caries scores of the molar teeth were compared among these four strains, and the degree of genetic determination was estimated by analysis of variance. Statistically significant differences in caries scores were found among these strains (F344 > WKA > PVG/c > BN), and a high degree of genetic determination was obtained.

Analysis of Variance↗
PubMed1994

The high prevalence of the diabetic patients with a mutation in the mitochondrial gene in Japan.

Recently, an A to G transition at position 3243 in transfer ribonucleic acidLeu(UUR) [the 3243 base-pair (bp) mutation] originally found in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes has been identified in patients with diabetes and deafness. To determine the prevalence of the diabetic patients with this mutation in Japan, we screened 550 randomly selected cohorts of diabetic patients without prior information about clinical features such as type of diabetes, family history of diabetes, age of onset, and mode of therapy. We have identified 5 patients with this mutation, suggesting that approximately 0.9% of diabetic patients have the 3243 bp mutation. However, there were no subjects with this mutation in 250 controls with normal glucose tolerance. The percentage of mutant DNA in whole mitochondrial DNA did not correlate to the degree of symptoms. We conclude that the 3243 bp mutation in the mitochondrial gene plays an important part as a cause of diabetes in Japan.

Adolescent↗