Biomedical subjects

K Obata

Publications and source records attributed to K Obata.

At least 163 records · Page 9Linked to original sources

PubMed1993

Prognostic significance of selected lifestyle factors in urinary bladder cancer.

To examine the prognostic significance of lifestyle factors in urinary bladder cancer, we conducted a follow-up study of 258 incident bladder cancer patients, who were originally recruited in a case-control study in metropolitan Nagoya. Information on individual survivals was obtained from the computer data-file of the tumor registry of the Nagoya Bladder Cancer Research Group. Univariate analyses revealed significant associations of 5-year survivorship with educational attainment, marital status, drinking habits and consumption of green tea in males, and age at first consultation, histological type and grade of tumor, stage and distant metastasis in both sexes. After adjustment for age, stage, histology (histological type and grade) and distant metastasis by means of a proportional hazards model, drinking of alcoholic beverages was significantly associated with the prognosis of bladder cancer in males. Its adjusted hazard ratio was 0.46 (95% confidence interval: 0.26-0.79), favoring patients who had taken alcoholic beverages. In detailed analysis, ex-drinkers and all levels of current drinkers demonstrated hazard ratios smaller than unity, although no clear dose-response relationship was detected. No prognostic significance was found for such lifestyle factors as smoking habit, uses of artificial sweeteners and hairdye, and consumption of coffee, black tea, matcha (powdered green tea) and cola.

Adult↗

PubMed1993

S100a0 protein as a marker for tissue damage related to extracorporeal shock wave lithotripsy.

We assayed serum and urine S100a0 protein levels in patients with renal stones (n = 21) or ureteral stones (n = 18), before and after extracorporeal shock wave lithotripsy (ESWL) to evaluate tissue injury. Serum S100a0 protein levels increased significantly immediately after, and at 2 and 24 h after ESWL in patients with renal stones, and at 2 and 24 h after ESWL in patients with ureteral stones. Significant increases in urine S100a0 protein levels were observed immediately and 2 h after ESWL in both groups of patients. The patients receiving a higher number of shock waves had a more pronounced increase in serum S100a0 protein especially in the case of more than 3,500 shock waves. Because S100a0 protein exists at relatively high concentrations in the proximal renal tubules and skeletal muscles, serum and urine S100a0 protein levels appear to be useful markers of tissue injury, including damage in the kidney and skeletal muscles, in the early post-ESWL phase.

Adult↗

PubMed1993

[Autopsy results of an elderly case of Parkinson's disease and aorto-esophageal fistula who died of a massive hematemesis during prolonged bed rest].

An 81-year-old female patient with an 8-year history of Parkinson's disease was hospitalized because of aspiration pneumonia. The clinical course of her pneumonia was prolonged because of dysphagia with a short period of remission, and she required a long period of bed rest. She received supportive nutrition via a nasogastric tube and many peroral medications that consisted of 3 anti-Parkinsonian drugs and 5 anti-bacterial or anti-tussive agents. Six months after admission, she vomited fresh blood through the nasogastric tube, then went into hypovolemic shock. Hemodynamic stability was temporarily achieved by blood transfusion. Gastroduodenal endoscopic examination could not reveal the exact bleeding site because of massive blood clots. Five days later, the patient died of a massive hematemesis. Autopsy revealed 2 chronic longitudinal ulcers, each 1.7 x 0.4 cm in size, in the upper portion of the esophagus. One of them had developed a fistula to the aorta. Neither esophageal carcinoma nor a foreign body was detected around the fistula. Atherosclerosis of the aorta was mild and the perforation channel was covered with the esophageal epithelium. The fistula was assumed to be a product of local esophageal injury due to drug retention.

Aged↗

PubMed1993

[Clinical studies of renal pelvic and ureteral tumors: an analysis of 611 registered cases and progress of treatment].

A review of 611 cases of renal pelvic or ureter tumor registered in Tokai Urological Tumor Registry for the past 10 years from 1980 and comparison of results between the first and latter half was made. The number of renal pelvis tumor was 347 and that of ureter tumors was 264. Clinical stages and pathological grades of the tumor were as follows; Ta, 11.9; T1, 31.8; T2, 14.4; T3, 24.3; T4, 17.6% and G1, 10.5; G2, 49.3; G3, 33.0%. Higher stages and grades were observed in the recent 5 years. Of 409 cases (66.9% in total cases) treated by total nephroureterectomy, 28.3% of the first and 49.0% of the latter half were treated adjunctively by chemotherapy. Five years relative survival rates of these two groups were 49.4 and 47.3%, respectively, suggesting no improved results. A new treatment strategy such as neoadjuvant chemotherapy or lymphadenectomy is expected to improve the prognosis.

Adult↗

PubMed1993

The effects of glucose on plasma amino acids and pyruvate during upper abdominal surgery.

To assess the potential benefits of perioperative glucose administration, the plasma concentrations of insulin, free fatty acids, ketone bodies, amino acids, lactate, and pyruvate were measured in 20 patients undergoing partial gastrectomy. Ten patients received intravenous glucose at 10 g/h during the operation, and the other 10 patients, as control, received no glucose. Plasma glucose, insulin activity, pyruvate and alanine concentrations in the glucose-receiving group increased significantly during the operation in comparison with the control group. In contrast, in the glucose-receiving group the plasma ketone bodies and branched-chain amino acids, especially leucine and isoleucine, decreased significantly during surgery. These results suggest that administration of glucose stimulated insulin secretion and resulted in accumulation of the substrates such as pyruvate and alanine which were utilized readily in the body. Glucose administration is useful in suppressing catabolism during upper abdominal surgery.

Amino Acids↗

PubMed1992

A one-step sandwich enzyme immunoassay for human matrix metalloproteinase 3 (stromelysin-1) using monoclonal antibodies.

A one-step sandwich enzyme immunoassay (EIA) for matrix metalloproteinase 3 (MMP-3; stromelysin-1) was developed. The assay system used two simultaneous immunoreactions using a solid phase monoclonal antibody and a horseradish peroxidase-labeled monoclonal antibody (Fab'). The sensitivity of the assay system was 20 micrograms/l and linearity was obtained between 31 and 500 micrograms/l. The EIA system was capable of measuring both precursor and active forms of MMP-3 as well as the forms of MMP-3 complexed with tissue inhibitors of metalloproteinases. MMP-3 levels as measured by this assay are significantly higher in the sera of patients with rheumatoid arthritis as compared to those of healthy subjects and patients with osteoarthritis. Immunoblot analyses showed that in the sera and synovial fluids of patients with rheumatoid arthritis, MMP-3 is present in the 59- and 57-kDa precursor forms.

Animals↗

PubMed1992

Cloning and sequence analysis of cDNA for a neuronal cell membrane antigen, HPC-1.

A monoclonal antibody (mAb), HPC-1, labels the plasma membrane of the amacrine cell soma and inner plexiform layer in rat retina and other central neurons. HPC-1 antigen recognizes several proteins of about 35 kDa. In this study, an HPC-1 positive cDNA, HPC-113, was isolated from a lambda gt11 cDNA library of the rat hippocampus. HPC-113 had the 894-base pair nucleotide sequence in an open reading frame and the calculated molecular mass of the deduced amino acid sequence (298 residues) was 33,989 Da, implying that HPC-113 contains almost the full-length coding region of HPC-1 antigen is an integrated membrane protein revealing the characteristic alpha-helical structure with periodical heptad repeats usually seen in proteins with coiled-coil structures. Although the entire amino acid sequence did not show significant homology to any proteins so far known, a few local sequences in the possible extracellular domain of the HPC-1 antigen molecule had notable homology to some partial sequences in the laminin B1 chain. These sequences of laminin are included in the portion which has neurite outgrowth and/or survival promoting activity. The HPC-1 gene was transcribed in nerve tissues much more predominantly than in non-neuronal tissues. Thus, HPC-1 antigen(s) was confined to be a newly identified neuronal cell membrane protein(s) localized in a subpopulation of neurons.

Amino Acid Sequence↗

PubMed1992

Immunocytochemical localization of synaptic vesicle-specific protein in Lewy body-containing neurons in Parkinson's disease.

We carried out an immunocytochemical examination of the brainstem and sympathetic ganglia of 5 autopsied patients with Parkinson's disease, using monoclonal antibodies against microtubule-associated protein 2 (MAP2) and synaptic vesicle-specific 38 kDa protein (SVP38). Lewy bodies (LBs) in the nerve cell somata were often immunoreactive for MAP2. Immunoreactivity of SVP38 in the somata of nerve cells was rarely demonstrated in the peripheral portion of the LBs. On the other hand, SVP38-immunoreactive (IR) LB-containing nerve cell processes were frequently found in the brainstem and sympathetic ganglia, considerably outnumbering MAP2-IR LB-containing nerve cell processes. These findings suggested that SVP38 is stored in LB-containing nerve cell processes and indicate that the majority of these processes are axons.

Aged↗

PubMed1992

Effect of acetylcholine on the highly stenotic coronary artery: difference between the constrictor response of the infarct-related coronary artery and that of the noninfarct-related artery.

To examine the constrictor response of the infarct-related stenotic coronary artery in comparison with that of noninfarct-related stenotic arteries, acetylcholine in maximal doses of 100 micrograms for the left and 50 micrograms for the right coronary artery was injected into the 16 infarct-related coronary arteries of 16 patients with previous myocardial infarction (group 1) and into 19 stenotic coronary arteries of 16 patients with stable angina without myocardial infarction (group 2). Acetylcholine's effects on lumen diameter and area were quantitatively analyzed at the stenotic segment and its proximal segment without significant stenosis. Acetylcholine decreased lumen diameter and area at the stenotic segments from 0.72 +/- 0.18 to 0.18 +/- 0.33 mm and from 0.45 +/- 0.22 to 0.10 +/- 0.22 mm2, respectively, in group 1 (both p less than 0.01) and from 0.75 +/- 0.22 to 0.49 +/- 0.30 mm and 0.48 +/- 0.29 to 0.26 +/- 0.23 mm2, respectively, in group 2 (both p less than 0.01). Acetylcholine decreased the diameter and area at the proximal segment from 2.71 +/- 0.75 to 2.38 +/- 0.6 mm and from 6.18 +/- 3.4 to 4.71 +/- 2.23 mm2, respectively, in group 1 (both p less than 0.01) and from 2.31 +/- 0.67 to 1.95 +/- 0.59 mm and from 4.5 +/- 2.97 to 3.22 +/- 1.96 mm2, respectively, in group 2 (both p less than 0.01). The changes in diameter and area at the stenotic segment in group 1 were significantly greater than those in group 2 (both p less than 0.01); there were no significant differences between groups in the changes at the proximal segment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMed1992

The 4th study of prophylactic intravesical chemotherapy with adriamycin in the treatment of superficial bladder cancer: the experience of the Japanese Urological Cancer Research Group for Adriamycin.

A multicentric randomised trial was conducted for the purpose of investigating the efficacy of intravesical chemoprophylaxis of superficial bladder cancers. A total of 443 patients (number of evaluable patients, 284) were registered from July 1987 to December 1989 and randomised into 3 groups. Group A received 21 intravesical instillations of Adriamycin (ADM) at 20 mg/40 ml physiological saline for 2 years after undergoing transurethral resection (TUR); group B was given the same dose as group A but received 6 intravesical instillations for 2 weeks before undergoing TUR; and group C served as a control and underwent TUR only. Better prophylactic effects were obtained in group A. The overall non-recurrence rates calculated for groups A and B differed significantly (P less than 0.05) on day 240, and those determined for groups A and C were also significantly different (P less than 0.01) on day 480. No benefit was obtained using intravesical instillation prior to TUR (group B). The major side effects encountered were pollakisuria and miction pain, which occurred in 32% of the patients in group A and in 52% of those in group B.

Administration, Intravesical↗

PubMed1992

Long-term results of intravesical chemoprophylaxis of superficial bladder cancer: experience of the Japanese Urological Cancer Research Group for Adriamycin.

Long-term results were analyzed in terms of tumor progression and survival in patients with superficial bladder cancer who were enrolled in the second intravesical chemoprophylactic study of the Japanese Urological Cancer Research Group for Adriamycin, which was started in July 1982. This study was a prospective, randomized, controlled trial conducted on primary tumors treated with a long-term instillation regimen that involved control versus intravesical instillations of Adriamycin or mitomycin C given once a week for the first 2 weeks, once every other week for 14 weeks, once a month for 8 months, and once every 3 months for 1 year, for a total of 21 instillations in 2 years. An analysis of the prophylactic effects of such treatment on bladder tumors after TUR has previously been performed, and the results have been published elsewhere. The present study represents a follow-up of the above trial. Of the 671 cases previously analyzed with regard to tumor prophylaxis, 158 cases (23.5%) were eligible to be followed for tumor progression and survival. A detailed comparison of the background factors between these 158 patients and the other 513 cases revealed no statistically significant difference. Thus, the 158 evaluable cases might reasonably be considered to represent all patients enrolled in the second study, and the results were thought to be reasonable enough to reflect the long-term efficacy of the long-term instillation regimen adopted in this study. The median follow-up for these 158 cases was 6.6 years. Tumor progression in terms of the disease stage and/or grade occurred in 43 of 127 patients who received prophylactic instillations and in 12 of 31 control cases. No significant difference in the incidence of tumor progression was found between the treatment and the control groups. In addition, no difference in survival was observed between the treatment group and the control group. Survival was also compared between patients who showed tumor progression and those who did not. All patients whose tumors did not progress survived, whereas the 7-year survival of those exhibiting tumor progression was less than 90%.

Actuarial Analysis↗

PubMed1992

Changes of drebrin expression in the visual cortex of the cat during development.

The expression of and developmental changes in drebrin were studied in cat visual cortex using immunohistochemistry and immunoblot analysis. Drebrin is a developmentally regulated brain protein which in the chicken has characteristic changes in expression related to developmental stage. A monoclonal antibody (MAb M2F6) raised against drebrin, was found to label the neuropil of the kitten visual cortex in the early postnatal period. At 1-3 weeks of age, the staining was prominent in layer IV of the visual cortex. The immunoreactivity, however, was found to be dramatically decreased around the end of the sensitive period for ocular dominance plasticity (approximately 3 months of age). In the adult visual cortex, almost no immunostaining was observed. These developmental changes revealed by an immunohistochemical method were confirmed using immunoblot analysis. Upon immunoblot analysis after SDS-PAGE of protein from the kitten visual cortex, MAb M2F6 was found to recognize two protein bands with molecular weights of 130 kDa (drebrin E) and 140 kDa (drebrin A). The developmental profile of the intensity of the two bands of the drebin closely parallels in time the postnatal changes in cortical susceptibility to visual deprivation. These results indicate that the expression of drebrin in kitten visual cortex is restricted to the early postnatal period and suggest that it may play an important role in the experience-dependent modification of cortical circuitry during the sensitive period.

Aging↗

PubMed1992

Retinoic acid-induced neural tube defects with multiple canals in the chick: immunohistochemistry with monoclonal antibodies.

When retinoic acid was injected into chicken yolks before incubation, various types of neural tube defect (NTD) were induced in 38-46% of the embryos after 48-96 h of incubation. The cranial NTD consisted of a delay in closing of the neural plate in 48-h embryos and some remained as disorganized, hyperplastic masses in older embryos. In spinal NTD of 48-h embryos the posterior neuropore remained widely open. In older embryos with a closed posterior neuropore, the neural tube appeared dissociated or disorganized locally at the trunk level. The tissue consisted of a dorsally-situated, neural-plate-like structure and a ventrally-located cell mass containing multiple canals. Although the location was different, this arrangement was similar to the overlap zone which appears between primary and secondary neurulation in normal development. Immunohistochemistry was performed using monoclonal antibodies which selectively stained various components of chick tissue. Considering the similarity in neural tube formation between chick and human, this experimental NTD may provide clues to understanding the etiology of human myelomeningocele.

Animals↗

PubMed1992

Cortical synaptogenesis in congenitally hydrocephalic HTX-rats using monoclonal anti-synaptic vesicle protein antibody.

We attempted to develop a method for investigating impairment of synaptogenesis quantitatively involving measurement of the fluorescence intensity emitted by immunohistochemically stained 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 increased nearly in parallel with that in non-hydrocephalic HTX-rats up to the 21st postnatal day. On the 28th postnatal day, the fluorescence intensity showed a marked reduction (P less than 0.01). This finding indicates that despite the presence of continuous pressure due to progressive ventricular dilatation after birth, synaptogenesis in the cerebral cortex may be relatively resilient.

Aging↗

PubMed1992

Cloning of drebrin A and induction of neurite-like processes in drebrin-transfected cells.

The developmentally-regulated neuron-specific protein, drebrin A, is expressed first at the time of outgrowth and maturation of dendrites, and is localized within dendrites of the adult brain. A cDNA clone of adult rat drebrin A was isolated and sequenced. There is no overall homology with other reported protein sequences except chicken drebrins. We constructed the expression vector MIW-DA containing the drebrin A cDNA. Transfection of nonneuronal cells with MIW-DA induced the formation of highly branched neurite-like cell processes. In these process-bearing transfectants, expressed debrin A is concentrated in submembraneous regions of the cell. Furthermore, actin concentration is higher in these cells than other fibroblasts. These results suggest a possible role of drebrin A in neurite outgrowth.

Amino Acid Sequence↗

PubMed1992

Effect of extracorporeal shockwave lithotripsy for urolithiasis on concentrations of creatine kinase isozymes in patient serum and urine.

To determine whether extracorporeal shockwave lithotripsy (ESWL) for urolithiasis causes renal injury, we immunoassayed creatine kinase isozymes (CK-B and CK-M) in serum and urine from patients with renal stone (n = 21) and ureteral stone (n = 18) before and after (0, 2, and 24 h) ESWL. CK-B is generally present in renal tissue at relatively high concentrations, whereas CK-M is found at low concentrations. CK-B and CK-M levels were enhanced both in the serum and urine samples after ESWL in both groups of patients but CK-B levels return to almost normal very rapidly. Because CK-M, which is mainly localized in muscle tissue, also increased in both groups, the increased CK-B in serum after ESWL might be derived not only from kidney but also from muscle tissues which also contain a significant level of CK-B. These results suggest that significant tissue injury, including kidney and muscles, might be caused by ESWL treatment for urolithiasis but there is no long-term renal adverse effect, and that creatine kinase isozymes in serum and urine might be useful markers of tissue injury by such treatment.

Adult↗

PubMed1992

[The role of neuronal cytoskeleton associated proteins in neuronal network formation].

There have been many studies to determine extrinsic factors that may regulate the neuronal migration and growth of axons and dendrites. However, the intracellular mechanism, especially the regulation of cytoskeleton, has not been clarified. It has been reported that actin filament crosslinking protein, MAR-CKS, play roles in cell motility through cytoskeletal rearrangement accompanied by rapid, PKC-dependent phosphorylation. Recently, we have demonstrated that neuron-specific actin binding protein, drebrin, changed the stability and distribution of microfilaments within the fibroblast and formed highly-branched dendrite-like cell processes from their cell perimeters. It has also been reported that overexpression of microtubule associated protein, tau, in a fibroblast induced long axon-like cellular processes. This review will focus on dynamic regulations of the microfilament by drebrin and those of the microtubules by MAP2 and tau. Since all kinds of cytoskeletons are related to each other, the binding ability of neurofilament H to microtubules and that of MAP2 to neurofilaments were also discussed.

Actin Cytoskeleton↗

PubMed1992

Peritoneal cytology in endometrial carcinoma.

Peritoneal cytology is accepted as part of the evaluation for patients undergoing laparotomy for a suspected or proven gynecologic malignancy. The study subjects were 83 patients with endometrial carcinoma. We investigated the significance of peritoneal cytology in endometrial carcinoma. Cytological positive results were observed in 11 (23%) of the 48 T1 cases, 9 (50%) of the 18 T2 cases and 4 (50%) of the 8 T3 cases. Cytological positive rates by histological differentiations were 14 (28%) for 50 G1 cases, 4 (36%) for 11 G2 cases and 6 (46%) for 13 G3 cases. Cytological positive results were found in 11 (28%) of 39 cases of less than 1/3 of intramuscular infiltration and 13 (37%) of 35 cases of 1/3 or more infiltration. Five (56%) of 9 metastasis cases and 17 (29%) of 59 nonmetastasis cases were found positive cytologically. An analysis of the data indicated that the influence of positive peritoneal cytology on recurrence superceded that of other known risk factors, such as grade, myometrial invasion, extrauterine disease, and lymph node metastasis. The patients with normal cytological findings at laparotomy tend to have a significantly (p less than 0.01) better prognosis than similar patients with abnormal cytological findings.

Adenocarcinoma↗