Search PubMed⌕ Search

Biomedical subjects

N Nishida

Publications and source records attributed to N Nishida.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Intimal hyperplasia growth after stenting of modified gianturco Z stent in an experimental study].

Three types of modified Gianturco Z stents, which included some solder at the bend portion in group 1, a little solder in group 2 and no solder in group 3, were placed in the jugular vein in order to evaluate the degree of intimal hyperplasia growth in five dogs. Four weeks later, venography and histological examination after venectomy were performed. Stenosis was 32.7 +/- 6.9% at the bend portion in group 1, 27.0 +/- 6.0% in group 2 and 14.0 +/- 6.5% in group 3. The results indicate that stents without solder are preferable for the venous system.

Animals↗
PubMed1994

Amplification and overexpression of the cyclin D1 gene in aggressive human hepatocellular carcinoma.

We analyzed the genetic alterations of the cyclin D1 and INT-2 genes in hepatocellular carcinomas (HCCs) from 45 patients. Among these, expression of the cyclin D1 mRNA was also analyzed in 18 of them by Northern blotting. The cyclin D1 gene was amplified 3-16 fold in five HCCs (11%); among these, the INT-2 gene was also amplified 2-10 fold in four HCCs. We analyzed the mRNA of cyclin D1 in four HCCs with gene amplifications, and 6-10 fold overexpressions were detected in all of them. Because the cyclin D1 gene was amplified in patients at an advanced stage of HCC with rapid tumor growth, it appeared to be associated with the aggressive behavior of tumors. Studies on loss of heterozygosity on chromosome 13q, where the retinoblastoma (RB) gene is located, indicated that all HCCs with an amplified cyclin D1 gene retained heterozygosity on chromosome 13q. These results suggest that amplification and overexpression of the cyclin D1 gene result in the rapid growth of a subset of HCC, even though the function of the RB gene is retained.

Carcinoma, Hepatocellular↗
PubMed1994

The purification, characterization, cloning and sequencing of the gene for a halostable and thermostable leucine dehydrogenase from Thermoactinomyces intermedius.

Leucine dehydrogenase has been purified to homogeneity from a moderate thermophilic actinomycete, Thermoactinomyces intermedius IFO 14230. The enzyme can be stored without loss of its activity at a low temperature (e.g., 4 degrees C) for over two years. The enzyme was more thermostable at higher concentrations of salts such as NaCl and KCl. It retained about 90% of activity on incubation at 70 degrees C for at least 40 min in the presence of 3 M NaCl. The Michaelis constants for NAD, L-leucine, NADH, 2-oxoisocaproate and ammonia were determined to be 0.36, 2.0, 0.042, 0.63 and 118 mM, respectively, from initial-velocity analyses. The enzyme showed pro-S stereospecificity for hydrogen transfer of NADH in the reductive amination. The enzyme gene was cloned into Escherichia coli and its complete DNA sequence was determined. The leucine dehydrogenase gene (leudh) consists of a 1098-bp open reading frame and encodes 366 amino acid residues corresponding to a subunit (M(r) 40586) of the octameric enzyme. The amino acid sequence of the enzyme showed 80.7% similarity with that of the Bacillus stearothermophilus enzyme. The enzyme was overproduced in E. coli JM 109 having a recombinant plasmid, pULDH2, which was constructed from pUC18 and the leudh gene. The enzyme was purified from the cell extract to homogeneity in one day, with 78% recovery.

Actinomyces↗
PubMed1994

[Self-expandable metallic stent therapy for inferior vena cava obstruction secondary to malignancy: clinical observations].

To evaluate the self-expandable metallic stent therapy for inferior vena caval obstruction (IVCO) secondary to malignant liver tumors, changes in caval pressure, the symptoms and hemobiochemical values were observed. Among 16 IVCO cases with higher caval pressure than 20 cmH2O at the peripheral caval lumen to the stenosis, nine cases consisting of five extracaval compression cases and four intravenous tumor thrombi cases subjected the stent therapy. Other three subjected radiotherapy and the other four cases inactive supportive care. Immediately after the Z-stent implantation, the averaged caval pressure distal to the stenosis decreased from 27.7 +/- 3.5 cmH2O to 14.7 +/- 2.6 cmH2O. One case developed 8 cmH2O increase of right atrial pressure but no lung edema. The urine excretion volume increased after stent. The decrease in caval pressure correlated with the urine volume of the day after the stenting (gamma = 0.83), symptomatic improvements of leg edema (gamma = 0.68), ascites (gamma v 0.51) and scrotal edema (gamma = 0.70). Five cases showed gradual increase in platelet number. All elevated LDH and elevated fibrinogen value decreased. These changes would suggest physiologic benefits of the IVC stent therapy. Compression cases showed better improvements and courses than the thrombi cases. Two thrombi cases endured severe conditions suspected of triggered by the procedure. Conclusively, the stent therapy to the IVC obstruction was thought to effect hemodynamically and hematobiochemically.

Aged↗
PubMed1994

[A twining method for struts connection in Z-stents].

To compose Gianturco Z-stents without welding, a twining method was applied. The link portion of the struts of were spirally entwined by a thin stainless steel wire of 0.1 mm in diameter. The directional balance of spring force of the twined stents compared favorably with that of the conventionally welded stents. This twining method has theoretical benefit of less susceptible to corrosion than soldering. Then the twining method was thought to be beneficial in composing Z-stents.

Equipment Design↗
PubMed1994

Acute toxicity of lipiodol infusion into the hepatic arteries of dogs.

RATIONALE AND OBJECTIVES: The authors studied the acute toxicity of percutaneous transcatheter hepatic artery infusion of iodized poppy oil fatty acid ester (Lipiodol, Laboratoire Guerbet, Aulnay-sous-Bois, France). METHODS: Lipiodol dosages of 0, 0.25, 0.5, 1.0, and 2.0 mL/kg were infused into the hepatic arteries of 10 beagles. Enzymatic and radiographic alterations were assessed. RESULTS: After the infusion of Lipiodol, the dogs showed body weight loss and hypoalbuminemia attributable to decreased food intake, transient elevation of the aspartate transaminase and alanine transaminase, and continuous increase in alkaline phosphatase. The controls did not show any significant change. The radiographs obtained immediately after and 2 weeks after the infusion showed dose-dependent accumulation of Lipiodol in the liver. After 2 weeks, histologic examination of livers and lungs showed dose-dependent (r = .9) retention of oily droplets in sinusoids and pulmonary capillaries. Interlobar pericholangitis was found in four dogs infused with Lipiodol. Pulmonary inflammatory reaction was observed with capillary oil embolism. Oil droplets also were found in the pancreas and the brain. CONCLUSIONS: Lipiodol infusion of the hepatic artery resulted in dose-dependent circulation and embolism of Lipiodol droplets via sinusoids and via pulmonary capillaries into the systemic circulation.

Acute Disease↗
PubMed1994

Pyridonecarboxylic acids as antibacterial agents. VIII. Synthesis and structure-activity relationship of 7-(1-aminocyclopropyl)-4-oxo-1,8-naphthyridine-3-carboxylic acids and 7-(1-aminocyclopropyl)-4-oxoquinoline-3-carboxylic acids.

4-Oxo-1,8-naphthyridine- and 4-oxoquinoline-3-carboxylic acids (2a, b and 3a-1) possessing a 1-amino-cyclopropyl group at the 7-position have been synthesized and evaluated for in vitro antibacterial activities. The three quinolones (3d, h, i) exhibited potent antibacterial activities against both gram-positive and gram-negative bacteria, which are comparable to those of ciprofloxacin (CPFX) and ofloxacin (OFLX). Among the three compounds, the best pharmacological and pharmacokinetic profile was obtained with 3i, an OFLX analogue, which was considerably less toxic than three reference quinolones (1, CPFX and OFLX).

4-Quinolones↗
PubMed1994

Investigation of type IIC von Willebrand disease.

Type II von Willebrand disease (vWD) is characterized by qualitative abnormality of von Willebrand factor (vWF). It is characterized by the absence of the largest, or the largest and intermediate-size plasma vWF multimers. Type IIC vWD is a very rare variant subtype. We report the tenth case of type IIC vWD who is a 32-year-old Japanese with a history of lifelong mild bleeding problems. The multimeric analysis of vWF of the patient's plasma revealed that the multimers were composed of the increased smallest multimer and progressively decreased larger multimers, with each multimer replaced by a single band instead of a normal triplet structure. The family study highly suggested that the propositus is the first case of homozygote for type IIC vWD gene, although previous studies have suggested that type IIC vWD is due to double heterozygosity of two different mutant genes. The patient's von Willebrand factor antigen showed a slight response to 1-deamino-8-D-arginine vasopressin (DDAVP), whereas his ristocetin cofactor showed no response. The patient responded very well to an intermediate-purity factor VIII concentrate, and then underwent cholecystectomy without bleeding problems.

Adult↗
PubMed1994

Treatment with cilazapril, angiotensin-converting enzyme inhibitor, changes the affinity of arginine vasopressin receptor in the kidney of the spontaneously hypertensive rat.

To elucidate the interaction between the renin-angiotensin system and arginine vasopressin (AVP), we investigated the change in the renal AVP receptor in the spontaneously hypertensive rat (SHR) treated with an angiotensin-converting enzyme (ACE) inhibitor, cilazapril. SHR (age 15 weeks) were given oral cilazapril 10 mg/kg body weight daily for 25 days (ACEI group). Systolic blood pressure was significantly decreased in the ACEI group as compared with the untreated SHRs (control group) after day 2. Urine volume in the ACEI group was 3- to 5-fold higher than that in the control group. Under these conditions, the renal AVP receptor was studied using the radiolabeled receptor assay (RRA) of [3H]-AVP from renal medulla membrane fractions. The serum concentrations of sodium, potassium, chloride, urea nitrogen and creatinine were not significantly different between the two groups. The plasma concentration of AVP in the ACEI group was higher than that in the control group. The dissociation constant (Kd) in the ACEI group was significantly lower than that in the control, although there was no significant change of maximum binding capacity (Bmax) between the two groups. We previously reported that the number of renal AVP receptors decreased in rats with diabetes insipidus which were treated with lithium, suggesting that the change in the AVP receptor is a primary cause of polyuric state induced by lithium. In the present study, the diuretic state and the decrease in blood pressure induced by cilazapril resulted in a marked decrease in the Kd of the renal AVP receptor and an increase in the plasma AVP level. It is suggested that plasma AVP and renal AVP receptors in SHR responded to the diuretic state induced by cilazapril by increasing the secretion and renal receptor affinity. We conclude that the AVP system plays an important role in the regulation of the fluid balance under diuretic conditions caused by ACE inhibitor treatment.

Animals↗
PubMed1994

Alteration of renal receptors for atrial natriuretic peptide and vasopressin in spontaneously hypertensive rats treated with antihypertensive diuretics.

To investigate the alteration of the renal atrial natriuretic peptide (ANP) and arginine vasopressin (AVP) receptors in the controlled hypertensive state of spontaneously hypertensive rat (SHR) treated with antihypertensive diuretics, 12 weeks old SHRs were administered an antihypertensive diuretic, furosemide, trichloromethiazide, or indapamide, daily for 10 days and investigated by radiolabeled receptor assay (RRA) of ANP and AVP. The urine volume was significantly increased in all groups treated with antihypertensive diuretics as compared with the untreated control group on day 3. Systolic blood pressure was significantly decreased in groups treated with both trichloromethiazide and indapamide. The number of renal ANP receptors decreased; affinity was increased only in the SHR administered indapamide. The affinity of the renal AVP receptor was also decreased in that group. Alteration of ANP and AVP receptors was observed only in the group treated with indapamide. This indicates that the ANP and AVP receptor in the kidney of SHR was changed not only by diuresis or reduction of blood pressure, but by the pharmacological action of indapamide.

Animals↗
PubMed1993

Role and mutational heterogeneity of the p53 gene in hepatocellular carcinoma.

The mutational spectrum of the p53 gene was analyzed in 53 hepatocellular carcinomas. Somatic mutations of the p53 gene were detected in 17 cases (32%). Among these 17 mutations, 9 were missense mutations; the mutations in the other 8 cases were nonsense mutations, deletions, or mutations at the intron-exon junctions. These mutations were found in a wide region stretching from exon 4 to exon 10 without any single mutational hot spot. G:C to T:A transversions were predominant, suggesting the involvement of environmental mutagens in the mutagenesis of the p53 gene in a subset of the hepatocellular carcinoma cases. Mutations of the p53 gene occurred frequently in advanced tumors, although several tumors in the early stages also showed mutations. A deletion map of chromosome 17 was constructed by using 10 polymorphic probes and was compared with the p53 gene mutation in each case. Loss of heterozygosity (LOH) on chromosome 17p was observed in 49% of the cases (24 of 49), and two commonly deleted regions were detected (around the p53 locus and at 17p13.3 to the telomere). Sixteen of the 17 cases with p53 gene mutations showed LOH around the p53 locus, and mutations were rare in hepatocellular carcinomas without LOH. However, no mutations were detected in 8 cases with LOH on 17p, suggesting the possibility that an unidentified tumor suppressor gene(s) located on 17p may have also been involved in hepatocarcinogenesis.

Base Sequence↗
PubMed1993

MRI of the head in the evaluation of microcephaly.

Fifty-five patients with microcephaly (head circumference < -2SD) were identified. The 55 patients were divided into two groups, consisting of group 1 (34 cases) in which genetic causes were considered primary, and group 2 (21 cases) in which intrauterine and/or postnatal acquired factors were thought to be responsible. MRI abnormalities were present in 80% of the total series: 68 and 100% in groups 1 and 2, respectively. In group 1, migration abnormalities were the most prominent and mental retardation was the major neurological handicap, while in group 2, hydranencephaly and infarction secondary to brain circulatory derangements were the most frequently observed abnormalities, with severe multiple handicaps such as cerebral palsy, epilepsy and mental retardation seen. Head MRI was considered indispensable in the investigation of the causes of microcephaly and in determining the neurological prognosis of affected patients.

Agenesis of Corpus Callosum↗
PubMed1993

An unusual heterotopia of pyloric glands of the stomach with inverted downgrowth.

A rarely reported, large heterotopia of gastric glands in the submucosal layer of the stomach is observed in a 79 year old Japanese man with early gastric cancer. Histologically, it consists of marked hyperplasia of benign foveolar-type epithelia and tubular glands which instead of growing upwards grow downwards into the submucosa. Immunohistochemically, many gastrin-positive G cells are observed within it, indicating the existence of independent pyloric-type glands from the surrounding mucosa with intestinal metaplasia. Muscle actin-positive fascicles, derived from the muscularis mucosae, are demonstrated to branch into it and to encapsulate it. This result suggests that the present lesion may not represent a truly submucosal ectopic location, but an inverted downgrowth of the mucosa into the submucosa, thus resembling an inverted polyp of the colon. An awareness of this unique lesion is important in order that it not be mistaken for a submucosal extension of the primary adenocarcinoma.

Aged↗
PubMed1993

Self-expandable spindle for transcatheter vascular occlusion: in vivo experiments. Work in progress.

A mechanical vascular occluder was studied in eight pigs to test its efficacy in arteries of different diameters, stability over time, and safety in placement. The main component is a self-expandable spindle made of tubular stainless steel mesh. Simple steel spindles, double spindles, and Dacron-core spindles were placed in the common carotid artery, main renal artery, renal artery branches, and infrarenal aorta. Follow-up arteriograms were obtained immediately, 30-60 minutes, and (except for aortic spindles) 7 days after deployment. The left common carotid artery was occluded in all pigs, regardless of spindle type. In the main renal artery and its branches, simple steel spindles did not achieve complete occlusion. Double and Dacron-core spindles produced immediate occlusion without recanalization on the 1-week follow-up arteriogram, except for one spindle with an incomplete Dacron core and two spindles that did not completely fill the arterial lumen. Two Dacron-core spindles achieved immediate complete occlusion of the infrarenal aorta. No migration was seen with any spindle.

Animals↗
PubMed1993

Self-expandable metallic stent therapy for superior vena cava syndrome: clinical observations.

PURPOSE: To study clinical and physiologic aspects of Z-stent therapy for superior vena cava (SVC) syndrome secondary to malignant disease. MATERIALS AND METHODS: Signs and symptoms of SVC syndrome were classified, graded, and scored in 11 cases. Six patients with caval pressure higher than 22 mm Hg peripheral to the stenosis underwent stent therapy. RESULTS: Immediately after Z-stent implantation into the stenotic lesion, the diameter of the constriction increased from 3.3 mm +/- 2.0 (mean +/- standard deviation) to 14.0 mm +/- 3.2, the mean caval pressure peripheral to the stenosis decreased from 26.6 mm Hg +/- 2.5 to 8.9 mm Hg +/- 0.7, and the symptom score decreased from 6.7 +/- 1.8 to 1.3 +/- 1.4. The caval pressure, lesion diameter, and symptom score correlated highly with each other. One complication--transient pulmonary edema attributable to volume overload caused by reperfusion--was observed. Mean survival exceeded 7.1 months. CONCLUSION: Stent placement could be a useful treatment for refractory SVC syndrome.

Aged↗
PubMed1993

Purification and properties of extremely thermostable glutamate dehydrogenases from two hyperthermophilic archaebacteria, Pyrococcus woesei and Pyrococcus furiosus.

Glutamate dehydrogenase (L-glutamate: NADP oxidoreductase, deaminating, EC 1.4.1.4) from the hyperthermophilic archaebacteria Pyrococcus woesei and P. furiosus were purified to homogeneity from crude extracts. The enzymes had similar enzymological properties: molecular mass, subunit structure, optimum pHs for the oxidative deamination and reductive amination, substrate specificity and coenzyme specificity as well as thermostability; the activity was not lost after incubation at 105 degrees C for 30 min. However, some differences were detected in resistance to urea denaturation and effects of salts on their activity and stability. The N-terminal 20 amino acid sequences of the two enzymes were identical.

Amino Acid Sequence↗