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Biomedical subjects

K Obata

Publications and source records attributed to K Obata.

At least 181 records · Page 10Linked to original sources
PubMed1992

Significance of serum type-IV collagen levels in various liver diseases. Measurement with a one-step sandwich enzyme immunoassay using monoclonal antibodies with specificity for pepsin-solubilized type-IV collagen.

Serum type-IV collagen levels determined with a one-step sandwich enzyme immunoassay (EIA) using monoclonal antibodies with specificity for pepsin-solubilized type-IV collagen were compared with histologic changes in liver biopsy specimens from 107 patients with various liver diseases. Serum type-IV collagen levels were increased in the groups with liver diseases compared with controls. The serum type-IV collagen levels in the group with alcoholic cirrhosis showed significantly higher values than the other groups (P less than 0.05). A significant positive correlation was found between the serum type-IV collagen level and the degree of fibrosis or cell infiltration in 107 patients. Immunolocalization of type-IV collagen was observed around blood vessels and bile ducts increased in number in the portal tracts, with cell infiltration and fibrosis, increased around vessels in fibrous septa, and sinusoidal walls of areas with cell infiltration or necrosis in hepatic lobules, and along the boundary between fibrous septa and hepatocytes. The present data indicate that serum type-IV collagen may be a sensitive marker for active fibrosis and that the elevation of serum type-IV collagen level primarily reflects the enhancement of type-IV collagen synthesis and deposition in the liver tissue at the stage of active fibrosis in liver disease.

Adolescent↗
PubMed1992

[Application of ultrasonography in chest diseases--usefulness of ultrasonography and physiologic evaluation of low pressure vascular system].

Air and bones, which limit echo penetration to the lesion, are the major components of the thorax. Recently, however, there have been many reports concerning the valid application of ultrasonography for evaluation of chest diseases. In this paper, we report the usefulness of ultrasonography to analyze thoracic lesions based on our experience. Generally, ultrasonography is a method providing high resolution and real-time images. Using these characteristics, we tried to obtain physiological information concerning the hemodynamics of the right heart system. We addressed the results of our studies using ultrasonography as follows; 1) relationship between ventilatory change of IVC and central venous pressure, 2) estimation of pulmonary arterial pressure by measuring the size of the pulmonary artery, 3) dynamic changes of SVC configuration.

Hemodynamics↗
PubMed1992

[Quantitative fluorescence-immunohistochemistry of presynaptic terminals using a monoclonal antibody against a synaptic vesicle-specific protein (SVP-38) in paraffin sections].

We developed a method for investigating impairment of synaptogenesis quantitatively involving measurement of the fluorescence intensity emitted by immunohistochemically stained paraffin sections of rat brain using a monoclonal antibody (Mab 171B5) against a synaptic vesicle protein (SVP-38). We applied this method to congenitally hydrocephalic and non-hydrocephalic brains of HTX-rats, and compared the postnatal changes in the fluorescence intensity in the molecular layer of the cerebral cortex. In non-hydrocephalic HTX-rats, the fluorescence intensity remained nearly unchanged from the 1st to 7th postnatal day and then increased at an almost linear rate until the 21st postnatal day, when it reached 4.5 times the value on the 7th postnatal day. The increase thereafter was gradual until the 28th postnatal day. In hydrocephalic HTX-rats, the fluorescence intensity showed a marked reduction on the 28th postnatal day (p < 0.01). This finding indicated impairment of synaptogenesis. We believe that this method provides useful information for evaluating the impairment of synaptogenesis in various pathological conditions in mammarian brains. The basic aspects of this method which support its validity are also discussed.

Animals↗
PubMed1992

[Clinical evaluation of usefulness of cefixime (200 mg administered once daily) in the treatment of acute uncomplicated cystitis].

A comparative study of cefixime (CFIX), a new oral cephem antibiotic, was carried out at the Department of Urology, Nagoya University Hospital and its four affiliated hospitals to evaluate the clinical efficacy and safety of two dosage regimens of CFIX, given either in twice daily doses (BID group) or once daily dose (UID group), in the treatment of acute uncomplicated cystitis. Forty six female patients (BID group) were administered the daily dose of 200 mg in two divided doses for 3 days, 30 female patients (UID group) were administered 200 mg once daily for 3 days. The clinical efficacy was evaluated in 33 cases from the BID group and in 22 cases from the UID group, respectively, according to the criteria recommended by the Japan UTI Committee. In the BID group, the clinical efficacy was evaluated as excellent in 18 cases, moderate in 13 and poor in 2, with an overall clinical effectiveness rate of 94%. In the UID group, it was evaluated as excellent in 9 cases, moderate in 12 and poor in 1, with an overall clinical effectiveness rate of 96%. Safety was monitored in 71 patients, and only one case of stomatitis was seen in the UID group. This findings suggest that 200 mg once daily dosing regimen of cefixime is as effective as 100 mg twice daily dosing regimen in treatment of acute uncomplicated cystitis, and is well tolerated in terms of safety.

Acute Disease↗
PubMed1992

Surgical correction of foot deformities after stroke.

Of 104 patients with corrective surgery for foot deformities subsequent to a cerebrovascular accident from 1980 until 1983, 53 patients returned for clinical examination and 22 patients were evaluated by questionnaire and telephone interview. The average follow-up period was 6.4 years. The operative techniques were tenotomy of the toe flexors for hammer-toe deformity, lengthening of the aponeurosis of the gastrocnemius for equinus deformity, and transfer of the anterior tibial tendon or the posterior tibial tendon or the long toe flexors for varus deformity. In 74% of patients, correction was maintained; 79% did not use an orthosis; 51% could bathe unassisted; and 76% were satisfied with the results. The ability to walk was related to the degree of paralysis, the age of the patient at surgery, and the walking speed at discharge.

Cerebrovascular Disorders↗
PubMed1992

[A randomized study of pirarubicin (THP) versus adriamycin (ADM) for intravesical instillation therapy against superficial bladder cancer].

To determine the antitumor action by intravesical instillation prior to transurethral resection TUR, a randomized study on pirarubicin (THP) versus adriamycin (ADM) was performed for superficial, papillary and initially detected bladder cancers with participation of 21 Urological Clinics in 3 Tokai Prefectures. The instillation dose of 500 micrograms/ml was given 3 times per week for 3 weeks in both THP (n = 33) and ADM (n = 30) groups. The complete and partial response rates were 56.3% in THP group and 26.7% in ADM group. THP instillation was more effective against multiple tumors than a single tumor, stage Ta than T1 and grade G1 than G2 and G3. However, these findings were not statistically significant. Untoward effects were mainly bladder irritability and its frequency was 60.6% in the THP group and 23.3% in the ADM group. Contracted bladder was found in 2 of the 33 patients in the THP group and 2 of the 30 patients in the ADM group. The antitumor effect of a half dose of THP was equivalent to that of one dose of ADM, and the THP group showed a twofold higher frequency of side effects. Therefore, a clinical trial should be made comparing the effect of 500 micrograms/ml of THP and that of 1,000 micrograms/ml of ADM.

Administration, Intravesical↗
PubMed1991

Augmented secretion of brain natriuretic peptide in acute myocardial infarction.

In order to elucidate biosynthesis and secretion of natriuretic peptides in the early phase of acute myocardial infarction (AMI), we measured the plasma level of brain natriuretic peptide (BNP), a novel cardiac hormone secreted from the ventricle, in patients with AMI and compared with that of atrial natriuretic peptide (ANP). The plasma level of BNP increased rapidly (within hours from the onset of AMI) and markedly (greater than 100 times the normal level) as compared to that of ANP. The plasma ANP level correlated with pulmonary capillary wedge pressure (PCWP), whereas the plasma BNP level did not correlate with PCWP but highly correlated inversely with cardiac index. These results indicate that BNP is secreted from the heart much more acutely and prominently than ANP in the early phase of AMI, in association with left ventricular dysfunction.

Adult↗
PubMed1991

Immunohistological study on brains of Alzheimer's disease using antibodies to fetal antigens, C-series gangliosides and microtubule-associated protein 5.

An immunohistological study of Alzheimer's brains was performed using antibodies to C-series gangliosides and microtubule-associated protein 5 (MAP5), and their staining patterns were compared with those of antibodies to tau and beta-amyloid precursor protein. Antibodies to C-series gangliosides and MAP5, both of which are known to preferentially expressed in the fetal brains, immunostained dystrophic neurites of senile plaques, neurofibrillary tangles and neuropil threads abundant in 3rd and 5th layers in the cerebral cortex, all of which are considered to be pathological hallmarks of Alzheimer's disease. The immunostaining patterns of these structures by antibodies to C-series gangliosides and MAP5 were similar to those by the antibody to tau. These three antibodies also immunostained some neurons in Alzheimer's brain, although their staining patterns were slightly different from one another; i.e., both diffuse and granular patterns were seen by the antibody to tau, but only granular pattern by the antibodies to C-series gangliosides and MAP5. These neurons immunostained by these three types of antibodies appeared to be the precursors of the classical neurofibrillary tangles, as positively stained neurons were not seen in the brains of non-demented cases. The presence of fetal antigens such as the C-series gangliosides and MAP5 in Alzheimer's brain may suggest that regeneration or sprouting of neurons is ongoing in association with the re-induction of gene expression characteristic for the brain in the early stage of development.

Aged↗
PubMed1991

Induction of somatostatin by kainic acid in pyramidal and granule cells of the rat hippocampus.

Seizures were induced in rats by systemic administration of kainic acid and, 1.5-12 h after, expression of preprosomatostatin and c-fos mRNAs in 9 hippocampal areas and in the cerebral perirhinal cortex was investigated using in situ hybridization histochemistry. Immunohistochemistry was also performed to study somatostatin peptide. In the control animals preprosomatostatin mRNA was expressed in some cells in the dentate hilus, the stratum oriens and the stratum radiatum of Ammon's horn, the subiculum and the cortex. Starting 3 h after kainic acid administration preprosomatostatin mRNA was expressed in a subpopulation of granule and pyramidal cells which did not normally express it. Preprosomatostatin mRNA-positive cells were markedly increased in the subiculum. Immunohistochemical examination confirmed that preprosomatostatin mRNA in granule and pyramidal cells was translated into peptide. In contrast, c-fos mRNA was induced in most hippocampal and cortical neurons starting 1.5 h after the kainic acid injection. When diazepam was injected to suppress the generalized seizures, preprosomatostatin mRNA was still expressed in pyramidal and subicular cells but not in granule cells.

Animals↗
PubMed1991

Effect of H1 receptor stimulation on coronary artery diameter in patients with variant angina: comparison with effect of acetylcholine.

It has been suggested that histamine is involved in the pathogenesis of coronary spasm but its exact role remains unclear. H1 receptor stimulation of the coronary artery was performed with a selective intracoronary infusion of histamine (2 micrograms/min) in 21 patients with variant angina after blockade of the H2 receptor with cimetidine (25 mg/kg) and its effect on the coronary artery diameter was examined. Intracoronary injection of acetylcholine was also performed in 19 of the 21 patients. Ergonovine (0.2 mg) was intravenously administered in one patient. The coronary artery diameter was measured with cinevideodensitometric analysis. A mean plasma histamine concentration in the coronary sinus increased from 4 x 10(-9) to 7 x 10(-8) M 5 min after histamine infusion into the left coronary artery (n = 18). Coronary spasm was induced in 6 patients (29%) with histamine, in 18 (95%) with acetylcholine and in 1 with ergonovine. The effect of histamine on the luminal diameter was analyzed at the site of spasm in the 26 coronary arteries in which spasm was induced by acetylcholine or ergonovine. Of the 20 coronary arteries with a normal arteriogram or a fixed stenosis less than or equal to 50% of luminal diameter, histamine decreased the diameter in 4, increased it in 14 (70%) and caused no change in 2; of the 6 coronary arteries with a fixed stenosis greater than or equal to 75%, histamine decreased the diameter in 5 and increased it in 1. In the coronary arteries in which spasm was not induced by either acetylcholine or ergonovine, histamine increased the diameter, especially in those without advanced atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1991

Brain natriuretic peptide as a novel cardiac hormone in humans. Evidence for an exquisite dual natriuretic peptide system, atrial natriuretic peptide and brain natriuretic peptide.

Using a specific radioimmunoassay for human brain natriuretic peptide (hBNP) with a monoclonal antibody, we have investigated its synthesis, secretion, and clearance in comparison with those of atrial natriuretic peptide (ANP) in normal subjects and patients with congestive heart failure (CHF). Mean BNP-like immunoreactivity (-LI) levels in normal atrium and ventricle were 250 and 18 pmol/g, respectively. The plasma BNP-LI level in normal subjects was 0.90 +/- 0.07 fmol/ml, which was 16% of the ANP-LI level. In contrast, the plasma BNP-LI level markedly increased in patients with CHF in proportion to its severity, and surpassed the ANP-LI level in severe cases. There was a significant step-up of the plasma BNP-LI level in the coronary sinus (CS) compared with that in the aortic root (Ao) and the difference between these BNP-LI levels, delta(CS-Ao)BNP, also increased with the severity of CHF. In addition, the step-up of the BNP-LI level in the anterior interventricular vein [delta(AIV-Ao)BNP] was comparable to delta(CS-Ao)BNP, indicating that BNP is secreted mainly from the ventricle. Predominant BNP synthesis in the ventricle was also confirmed by Northern blot analysis. Catheterization and pharmacokinetic studies revealed that hBNP is cleared from the circulation more slowly than alpha-hANP; this was in part attributed to lower (about 7%) binding affinity of hBNP to clearance receptors than that of alpha-hANP. A predominant molecular form of BNP-LI in the heart and plasma was a 3-kD form corresponding to hBNP. These results indicate that BNP is a novel cardiac hormone secreted predominantly from the ventricle, and that the synthesis, secretion and clearance of BNP differ from those of ANP, suggesting discrete physiological and pathophysiological roles of BNP in a dual natriuretic peptide system.

Antibodies, Monoclonal↗
PubMed1991

[S100a0 protein and creatine kinase isozymes (CK-B & CK-M) in serum and urine might be useful markers for non specific tissue damages by extracorporeal shockwave lithotripsy (ESWL)].

In order to demonstrate that the extracorporeal shockwave lithotripsy (ESWL) for urolithiasis causes a renal damage, we immunoassayed S100a0 protein and creatine kinase isozymes (CK-B & CK-M) in the serum and urine from patients with renal stone (N = 21) and those with ureteral stone (N = 18) before and after ESWL. S100a0 protein and CK-B, which are localized in the proximal renal tubules at relatively high concentrations, were enhanced more or less both in the urine and serum samples after the treatment in both groups of patients. Since CK-M, which is mainly localized in muscle tissue, also increased in both groups of patients, S100a0 protein and CK-B may be derived not only from kidney, but also from muscle tissues.

Adult↗
PubMed1991

[Hormonal treatment of carcinoma of the prostate].

Efficacy of orchiectomy and intravenous administration of diethylstilbestrol diphosphate (DESP) for the treatment of prostatic carcinoma was evaluated on 184 patients treated between 1975 to 1989. The patients were between 49 to 88 years old with a mean age of 73.4 +/- 8.3 years. Clinical stage was A in 9.8%, B in 12%, C in 26.6% and D in 51.6%. The histologically well, moderately and poorly differentiated adenocarcinoma were observed in 20.9, 29.4 and 49.7%, respectively. The 5-year survival rate of stage A, B, C and D calculated with the Kaplan-Meier method were 90, 49, 60 and 34%, respectively. The 5- and 10-year survival rate of the patients who had received orchiectomy was 53 and 24%, respectively, while that of the patients without orchiectomy was 38 and 14%, respectively. The 5 and 7-year survival rate of the patients treated with intravenous administration of DESP was 54 and 34%, respectively while that of the patients without DESP was 46 and 31%, respectively. These findings suggest that orchiectomy and intravenous administration of DESP in any form prolonged patient survival compared with only oral administration of estrogens or antiandrogens. Reactivation was seen in 24 (40%) of the 60 patients under sufficient observation. Clinical relapse occurred within an average of 32.3 +/- 26.4 months after primary hormonal manipulation. The average time to relapse in stage D was shorter than that in stage B and C. Reactivation was observed in the patients on interrupted treatment earlier than in the patients on continuous administration of drugs. Cardiovascular death followed by endocrine therapy was 7.4% in this study.

Adenocarcinoma↗
PubMed1990

Differences in lipid composition between isolated growth cones from the forebrain and those from the brainstem in the fetal rat.

The lipid composition of nerve growth cone membranes isolated from rat fetal forebrain or brainstem by the sucrose density gradient method was analyzed biochemically and immunochemically. In the forebrain, growth cone membrane (GCM) contained lower levels of gangliosides than those from other heavier fractions, but it was not the case in the fetal brainstem at the same developmental stage. The distinctive features in the ganglioside composition of GCM are the predominance of GD3 and the presence of c-series gangliosides that are due to fetal expression in mammals. A unique acidic glycolipid, sulfoglucuronylparagloboside (SGPG), which is not present in adult brains, was first detected in both forebrain and brainstem GCM. Including such minor species, the ganglioside composition in forebrain or brainstem GCM was almost identical to other membrane fractions from the forebrain or brainstem. The compositional ratios of the major lipid classes in membranes, cholesterol and phospholipids, seemed to be common to forebrain GCM and brainstem GCM, as indicated by the identical values of phospholipid-to-protein (PL/Pr), cholesterol-to-protein (Ch/Pr), and cholesterol-to-phospholipid (Ch/PL) ratios for both. This study has revealed that GCM isolated from forebrain which is supposed to be at an earlier stage of neuronal differentiation than brainstem has less amounts of total gangliosides, high proportion of GD3 to GD1a and enriched c-series gangliosides as compared to brainstem GCM.

Animals↗
PubMed1990

The changes in arterial keton bodies during upper abdominal surgery.

The relationship between the arterial keton body ratio (AKBR: acetoacetate/Beta-hydroxybutyrate) and the plasma hormone activities were studied under a general anesthesia using enflurane group (group G) and a GO + Epidural group (group E) with continuous glucose loading (10 g.hr(-1)) during partial gastrectomy. In both groups, the AKBR increased significantly during the operation. The plasma insulin activity was significantly positively correlated with the AKBR and it was negatively correlated with log (Beta-hydroxybutyrate) in both groups. We could not find any significant difference of the AKBR between group G and group E. Our results indicate that the plasma insulin activity affects the arterial keton body ratio and that the AKBR must be evaluated considering the plasma hormone activity, especially insulin activity during the operation.

Journal Article↗