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Biomedical subjects

K Ohtsuka

Publications and source records attributed to K Ohtsuka.

At least 235 records · Page 13Linked to original sources
PubMed1985

Peripheral plasma concentrations of somatostatin-like immunoreactivity in newborns and infants.

Postprandial peripheral plasma concentrations of somatostatin-like immunoreactivity (SLI) were measured by RIA after extraction with acetone-petroleum ether in 98 normal newborns and infants. In 62 subjects, plasma concentrations of gastrin were determined simultaneously. The plasma levels of SLI increased progressively with age during the neonatal period. The mean plasma levels of SLI increased significantly from 19.5 +/- 7.5 (+/- SD) pg/ml in 29 cord blood samples to 29.0 +/- 17.2 pg/ml in 36 newborns aged 1-5 days. The mean postprandial level of plasma SLI was significantly higher in 18 infants aged 1-3 months (45.5 +/- 25.8 pg/ml) than in newborns and tended to decrease in infants aged 7-10 months after weaning (31.6 +/- 7.9 pg/ml). The mean postprandial levels of plasma SLI were significantly higher in newborns and infants less than 10 months old than in older children aged 8-12 yr (10.2 +/- 3.7 pg/ml). The gel filtration patterns of SLI of plasma extracts were similar in infants and older children. The changing pattern of mean plasma gastrin with age was similar to that of SLI, and individual plasma levels of SLI were significantly correlated with those of gastrin during the neonatal period. High concentrations of SLI are present in the peripheral circulation during the first 10 months of life. Thus, this peptide may play a significant role as a hormone in nutrient homeostasis in infants.

Aging↗
PubMed1985

[Effect of recombinant alpha-interferon on advanced renal cell carcinoma].

The present study was undertaken to assess the efficacy of single agent chemotherapy with alpha A-interferon or alpha 2-interferon for metastatic renal cell carcinoma. alpha A and alpha 2-Interferon were administered i.m. at a primary dose of 3 X 10(6) units/day to 13 patients. Two patients (15%) showed partial response; 1 patient (8%), minor response; 5 patients (38%), no change; 6 patients (46%), progressive disease. These preliminary observations indicate that these interferons are active antitumor agents in patients with renal cell carcinoma.

Adenocarcinoma↗
PubMed1985

[Transfer of ceftizoxime to renal tissues].

Serum and renal tissue concentrations of ceftizoxime (CZX) after intravenous dosing with 1 g were determined in 15 patients with renal disease. The highest serum concentration of CZX was 105 micrograms/ml 6 minutes after dosing and the lowest concentration was 10.5 micrograms/ml at 170 minutes. The highest renal tissue concentration was 155 micrograms/g and the lowest concentration was 7.46 micrograms/g. There were no correlation between the tissue concentrations and sampling time. Tissue to serum concentration ratios ranged from 0.28 to 5.73. These patients were divided into 3 groups; hydronephrosis, normal kidneys and renal atrophy according to pyelographic findings. Their renal tissue concentrations were compared with serum concentrations in each group. The tissue concentrations were lower than the serum concentrations in the first group, and were almost the same or higher in the other groups. CZX concentrations in the medulla and the cortex were determined in 5 patients; and were higher in the medulla in 4 of these patients. Urinary tract infection due to E. coli, K. pneumoniae, P. mirabilis, S. pyogenes or S. epidermidis was present in 5 of the 25 patients. Intravenous injection of 1 g of CZX provided therapeutically effective concentrations against these urinary tract infections.

Adult↗
PubMed1984

A desktop computer to visualize the intraluminal velocity profile and its clinical application.

Based on our previous study that the outcome of reconstructive surgery for lower limbs could well be predicted by flow waveforms and that this state was defined by variation of wall shear stress (tau) in a cardiac cycle, we set up a desktop computer that could calculate wall shear stress in a given patient. This work is based on a principle of a computational method for simulating pulsating blood flow. The flow data from the patient are sent to the waveform analyzer, where the intraluminal velocity profile as well as the shear stress variation is demonstrated. Our study revealed no late occlusion in patients with flow waveforms over 70 dynes/cm2 in tau-variation, early graft failure in those below 20 dynes/cm2, and late occlusion in considerable numbers of patients whose waveforms were between 70 and 20 dynes/cm2. Intraoperative use of the waveform analyzer disclosed the occult cause of obstruction, which would otherwise be overlooked, leading to a remarkable decrease in the rate of immediate graft failure. Follow-up of outpatients with this approach facilitated early detection of late failure, making it possible to repair the graft with minor surgery. Use of the waveform analyzer proved superior to ankle pressure index in predicting graft failure.

Aged↗
PubMed1983

A study on the reaction of human erythrocytes with hydrogen peroxide.

Membrane fluidity of human erythrocytes treated with H2O2 (1--20 mM) was studied using three kinds of fatty acid spin labels. A strongly immobilized signal appeared on exposure of erythrocytes to H2O2 but was not observed in either H2O2- or Fenton's reagent-treated ghosts or lipid vesicles prepared from H2O2-treated erythrocytes, indicating that the appearance of this signal necessitates the reaction of hemoglobin with H2O2 and is not due to lipid peroxidation. The ESR spectrum of maleimide-prelabeled erythrocytes showed an isotropic signal and the rotational correlation time (tau c) increased as the concentration of H2O2 was increased. Furthermore, maleimide labeling of H2O2-pretreated erythrocytes showed a strongly immobilized component, in addition to a weakly immobilized component. From the relative ratio of the signal intensity of hemoglobin and membrane proteins, it was found that label molecules bound predominantly to hemoglobin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of H2O2-treated erythrocytes demonstrated globin aggregation. Therefore, the changes in the ESR signal observed on H2O2 treatment may be due to some change in hemoglobin, such as globin aggregation or its binding to the membranes. The ESR spectrum of H2O2-treated erythrocytes at -196 degrees C is characterized by signals of nonheme ferric iron type (g equal to 4.3), low spin ferric iron, and free radical type at g equal to 2.00. At higher H2O2 concentrations, the ESR lines due to low spin ferric iron became broad and their peak heights decreased, compared with that at g equal to 2.00 or 4.3. These results indicate that oxidative stress such as decrease of membrane fluidity, lipid peroxidation, and globin aggregation in H2O2-treated erythrocytes is dependent on the reaction of hemoglobin with H2O2.

Adult↗
PubMed1983

[Functional recovery following surgical removal of traumatic epidural hematoma--factor analysis].

UNLABELLED: Factors contributing to functional recovery following evacuation of epidural hematoma were analyzed in 53 subjects. Subjects were limited to the cases with "pure" epidural hematoma. Fifty-three cases were classified into 3 groups based on presence or absence, and duration of preaggravation period (PAP) following occurrence of head trauma (Fig. 1). Level of consciousness at operation and at PAP is summarised in Fig. 2. Major neurological signs at operation are summarized in Table 1. Gradings of functional status were divided to 6 (Table 2). Gradings of 53 subjects which were judged 1 month after removal of epidural hematoma are summarized in Fig. 3. RESULTS: 1) As to outcome in relation to duration of preaggravation period (PAP) and consciousness level at operation (Fig. 4): The patients whose PAP was shorter and whose consciousness level at operation was more severe, took outcome of lower (worse) gradings. 2) As to outcome in relation to interval from the end of PAP to operation and PAP (Fig. 5): The patients whose PAP are within 3 hours, took outcome of relatively good recovery only when epidural hematoma was removed within 5.5 hours after the end of PAP. 3) As to outcome in relation to interval from the end of PAP to operation and consciousness level at operation (Fig. 6): The patients whose consciousness level at operation was better than semicoma took good recovery when epidural hematoma was evacuated within 5.5 hours after the end of PAP. This was right even in the patients who presented with decerebrate posture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1982

Degeneration of retinal neuroblasts by chinoform-ferric chelate.

The possible mechanism of neuropathic effect of chinoform was investigated using cultured retinal neuroblasts from chick embryos. Retinal neuroblasts completely degenerated by chinoform-ferric chelate within a day. This change, however,, was not observed with free chinoform or ferric ion alpha-Tocopherol had a potent protective effect on the toxicity of the chelate. From these results, it was concluded that the lipid peroxidation due to ferric ion chelated with chinoform incorporated into the membrane of nerve tissues is the most important step in induction of the neuropathy.

Animals↗