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Biomedical subjects

M Kawamura

Publications and source records attributed to M Kawamura.

At least 829 records · Page 46Linked to original sources
PubMed1985

[Changes in pancreatic hormones in portal blood and morphological changes of islet cells of Langerhans after hepatectomy].

Hybrid adult dogs weighing 12 to 15 kg were laparotomized before, one week, and one month after partial hepatectomy: Pancreatic tissues were taken and examined by the PAP staining. Also, the animals were intravenously injected via peripheral veins with 50 percent glucose 0.5 g/kg before, one week, and one month after surgery, and their portal blood was taken before, 5, 15, 30, 45 and 60 minutes after injection, and submitted to examination of insulin, glucagon, somatostatin and blood sugar levels. We obtained these results as follows. sigma IRI which represents an increment of insulin secretion after glucose loads, showed a decrease at one week after surgery (p less than 0.05) and an increase at one month after surgery (p less than 0.05). Somatostatin levels of portal blood showed marked increase after surgery (p less than 0.05). Observation on the area of Langerhans islets revealed approximately 4.6 fold hypertrophy from the size of 486 +/- 23 microns m2 before surgery to 2236 +/- 98 microns m2 one month after surgery (p less than 0.05). Insulin secreting B cells were found to contain increased secreting granules. Somatostatin secreting D cells increased 2.8-fold in number one month after surgery, showing mitotic figures.

Animals↗
PubMed1985

Rapid assay of N-butyl-N-(3-carboxypropyl)nitrosamine in rat organs and urine by high-performance liquid chromatography after derivatization.

The concentration of N-butyl-N-(3-carboxypropyl)nitrosamine (BCPN), which is the major metabolite of the carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN), was measured in the urine, thymus, liver, kidney, and bladder of rats orally administered with BBN. Since BCPN is a carboxylic acid, it forms an ester with 9-anthryldiazomethane (ADAM), which is a fluorescent labeling agent highly sensitive to carboxylic acids. Thus, BCPN and ADAM were reacted at 40 degrees for 1 hr, and the resulting ester was separated and measured by high-performance liquid chromatography (HPLC) with a reverse-phase type column. The range of measurement was 0 to 40 micrograms/ml, and the coefficient of variation (CV) was 3.8%. When 0.025% BBN was given orally to rats in tap water, the BCPN concentration in the urine was very high at 220 micrograms/ml, while it was 0.15 microgram/100 mg in the wet tissues of the thymus, 0.35 microgram/100 mg in the liver, 0.40 microgram/100 mg in the kidney, and 1.2 microgram/100 mg in the bladder. The BCPN concentration in the bladder, in which tumors are induced by the administration of BBN, was thus higher than those in the other organs.

Animals↗
PubMed1985

Normotriglyceridemic abetalipoproteinemia in infancy: an isolated apolipoprotein B-100 deficiency.

The plasma lipoproteins of a 1-year-old Japanese infant were studied because of malnutrition, severe decrease in plasma lipid level, and acanthocytosis. Plasma lipoprotein analysis revealed that low-density lipoproteins were deficient; however, low levels of triglyceride-rich lipoproteins were found in the plasma. On sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis, apoprotein B-48 and a faint band corresponding to apoprotein B-100 were detected in the lipoprotein fraction of density less than 1.006 g/mL when the infant was 6 months old. Apoprotein B-48 was more clearly detected after 1 year, but the band corresponding to apoprotein B-100 on the sodium dodecylsulfate gel electrophoresis had disappeared. The apoprotein B-48 content of the fraction with density less than 1.006 g/mL was about 0.05 to 0.3 mg/dL. The patient's lipoproteins consisted mainly of high-density lipoproteins. These results suggest that the disorder in this patient is caused by apoprotein B-100 deficiency.

Abetalipoproteinemia↗
PubMed1985

Streptozotocin diabetes: prolonged inflammatory response with delay in granuloma formation.

Inflammatory responses to carrageenin in streptozotocin-induced diabetic rats proved to be characterized by low values of granuloma tissue (tissue) weight and granuloma pouch fluid (fluid) volume, high values of fluid beta-glucuronidase (beta-Gl) and leucine aminopeptidase (LAP), and furthermore by high values of fluid lipid peroxide (LPO) and lactate dehydrogenase (LDH) and low values of fluid proamidase. These results in such diabetic rats were similar to those in rats injected with high doses of carrageenin except tissue weight and fluid volume. On the basis of measurements of three basic parameters required for coordinated observation of the inflammatory system, namely lysosomal enzymes, LPO, and proamidase (related respectively to the inflammatory response sensu stricto, to tissue damage, and to tissue repair), it can be concluded that the diabetic rats show an inadequately adapted inflammatory response, with decreased granuloma formation and reduced exudation, to noxious agents. This is probably due to a low sensitivity of the inflamed tissue in diabetic rats to noxious stimuli or chemical mediators, leading to a delay in the normal defence reaction of enhanced granuloma formation and exudation, thus resulting in a prolonged inflammatory response with a delay in wound healing.

Amidohydrolases↗
PubMed1985

[Studies on combined effect of hyperthermia and MTX to choriocarcinoma cell line (BeWo)].

Changes in cell growth and hormone production of the choriocarcinoma cell line BeWo were studied to determine the manner in which the change in the cell cycle due to antimetabolite MTX affects heat sensitivity. First of all, BeWo was treated with 10(-7)M-MTX for 48 hrs. on day 4. And heat (43 degrees C for 1 h.) was applied at various stages after MTX removal on day 6. At the same time, the change in the cell cycle induced by MTX was studied by autoradiography. The labeling index (L.I.), which was increasing until 90% by MTX exposure, still remained more than 80% up to 5 hrs. after MTX removal and then decreased to about 43% at 9 hrs. after MTX removal. The greatest effect on cell growth and HCG production was seen when heat was applied within 5 hrs. after MTX removal. And these 5 hrs. corresponded to the time when the L.I. was as high as 80 to 90%. When heat was applied more than 6 hrs. after MTX removal, the heat sensitivity was reduced in proportion to the degree of decrease in the L.I. These findings suggest that the change in the cell cycle induced by MTX has the greatest effect on the heat sensitivity of BeWo. It is therefore possible to conclude that synchronization of BeWo with S phase by using MTX or possibly other antimetabolites is very important in the application of hyperthermia.

Autoradiography↗
PubMed1985

[Cerebral venous thrombosis with familial antithrombin III deficiency].

A case of cerebral venous thrombosis with familial antithrombin III (AT III) deficiency was reported and we discussed the anticoagulant therapy of cerebral venous thrombosis from the viewpoint of AT III. The patient, a 17-year-old boy, was admitted to our clinic with severe bifrontal headache, generalized convulsions and progressive disturbance of consciousness. He developed deep vein thrombosis in his right leg and pulmonary emboli two years earlier when he was placed on heparin and so forth, followed by warfarin sodium. Warfarin was terminated 9 months prior to his recent illness. On neurological examination on admission, he was semicomatous with blurred disc margins, roving eye movements with right abducens nerve palsy, nuchal stiffness and right flaccid hemiplegia. Left carotid angiogram and CT scan revealed extensive superior sagittal sinus thrombosis, complicated with hemorrhagic infarcts in bilateral frontal lobes. When examined for coagulation studies, the patient and his father had decrease in AT III activity and antigen levels. He was treated successfully with antiedematous agents and anticonvulsants during acute phase of illness. He was thereafter placed on warfarin 5-6 mg/day with no further clinical thromboembolic event for 2 years 9 months. There was no neurological abnormality when he was last examined, although he was treated with valproic acid 1,200 mg/day and phenytoin 250 mg/day to control occasional adversive seizures. A coagulation study following infusion of 5,000 units of AT III was carried out. Warfarin was discontinued the day before the study. 0.64 U/kg of AT III administration resulted in a 1% increase in AT III level after the infusion. The biological half life of AT III was 14.4 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[A review of thirteen carotid surgeries in ten patients].

During the period of 3 years and 9 months (from September 1980 to May 1984), 44 patients with arteriosclerosis of the carotid arteries were seen at our hospital. In 10 of them, arterial reconstructive surgery was performed. There were 7 men and 3 women. Ages ranged from 50 to 75 years (mean, 61.9 years). They had a total of 13 lesions in the carotid arteries, which were composed of one complete obstruction, 10 stenoses, one aneurysm, and one tortuosity. These lesions were treated by either thromboendarterectomy (TEA), TEA along with vein patch, vein patch, or aneurysmorrhaphy. Three of these 10 patients were subjected to the second operation because of remaining disease or recurrence of symptoms.

Aged↗
PubMed1985

[Magnetic resonance imaging in agenesis of the corpus callosum].

The recent use of computed tomography (CT) scan is providing an easy diagnoses of agenesis of corpus callosum which had been difficult to diagnose only by clinical signs and symptoms. Since, more neuropsychological studies on agenesis of corpus callosum are being done, clinical details of agenesis of corpus callosum are being clarified. We examined magnetic resonance imaging (MRI) on 3 patients who were suspected to have agenesis of corpus callosum by CT scan. And we studied the usefulness of MRI in agenesis of corpus callosum. Case 1. We studied a thirty-two-year-old right-handed man with a one-year history of amyotrophic lateral sclerosis. He had no callosal disconnection syndrome. CT scan on horizontal view showed dilated third ventricle, the dilatation of the occipital horns and wide separation of the lateral ventricles. On coronal view, CT scan showed the absence of the corpus callosum, the concave mesial borders of the lateral ventricle, the dilatation of the third ventricle and its abnormal dorsal extent(bat-wing appearance). On sagittal MRI (the inversion recovery technique), the corpus callosum was absent and the convolutions and sulci were arranged radically centering the third ventricle (radial distribution). But the anterior commissure was preserved. Case 2. We studied a fourty-one-year-old right-handed man with a seven-year history of hyper ventilation syndrome. He had no callosal disconnection syndrome. CT scan showed the similar findings as those of case 1. On sagittal MRI (the inversion recovery technique), the corpus callosum was absent, and the convolutions and sulci showed radial distribution. But the anterior commissure was preserved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Solubilization and purification of Artemia salina (Na,K)-activated ATPase and NH2-terminal amino acid sequence of its larger subunit.

Membrane bound (Na,K)-ATPase partially purified from the nauplius larva of the brine shrimp, Artemia salina, was solubilized with the non-ionic detergent C12E8 in the presence of KCl. The addition of KCl was essential for protecting the enzyme against inactivation. With solubilization the enzyme could then be purified to apparent homogeneity. Electron microscopic observation of the purified enzyme revealed a homogeneous population of particles with a diameter of approximately 4 nm. The larger (alpha) subunit of the enzyme formed double bands on sodium dodecyl sulfate-polyacrylamide gels. NH2-terminal sequence analysis of the alpha subunit revealed the possible presence of two isoforms of (Na,K)-ATPase. At the third position a small but distinct amount of lysine was found in addition to glycine, suggesting that the two forms are different from each other at least at the third residue. The NH2-terminal sequence determined is as follows. NH2-Ala-Lys-Gly (Lys)-Lys-Gln-Lys-Lys-Gly-Lys-Asp-Leu-Asn-Glu-Leu-Lys-Lys-Glu-Leu-Asp-Il e-Asp -Phe-His-Lys-Ile-Pro- The sequence is abundant in hydrophilic amino acids, especially lysine, and is quite different from those of vertebrate enzymes reported so far.

Amino Acid Sequence↗
PubMed1984

Evidence for essential disulfide bonds in the beta-subunit of (Na+ + K+)-ATPase.

(Na+ + K+)-ATPase from dog kidney lost its activity when heated at 55 degrees C in the presence of 0.3 M 2-mercaptoethanol. Either heat treatment alone or addition of reducing agent at around 25 degrees C caused little inactivation. One disulfide bond per protomer (mol. wt. 146 000) was reduced in the inactivated sample but in active samples no reduction occurred. Neither K+-dependent phosphatase activity nor phosphoenzyme formation in the presence of Na+ was detected in the inactivated sample, suggesting that the disulfide bond was essential for the catalytic cycle of (Na+ + K+)-ATPase. This essential disulfide bond belonged to the beta-subunit, the glycoprotein component of the enzyme, indicating that the beta-subunit may be an integral component of the (Na+ + K+)-ATPase system.

Animals↗
PubMed1984

Immunohistochemical localization of Na+, K+-ATPase in the choroid plexus.

To determine if canine and rat choroid plexus Na+,K+-ATPase can be localized by immunoperoxidase staining after fixation and embedding, we prepared rabbit antiserum to purified canine kidney medulla Na+,K+-ATPase. When sodium dodecylsulfate polyacrylamide electrophoretic gels of purified canine kidney Na+,K+-ATPase and canine kidney microsomes were treated with antiserum followed by [125I]protein A and autoradiography, the canine microsomes and purified Na+,K+-ATPase showed a prominent radioactive band coincident with the alpha-, beta- and gamma-subunits of the purified canine kidney enzyme. When the rabbit immunoglobulin that was purified from the Na+,K+-ATPase antiserum through DEAE-cellulose ion exchange chromatography was used for immunoperoxidase staining of the choroid plexus fixed with Bouin's fixative, intense immunoreactive staining was present on the epithelial cells of both choroid plexuses but was not found in the tissue around the vessel. The staining was especially confined to apical surfaces of the epithelial cells. The same procedure was performed in the canine kidney, and immunostaining was obtained in the tubules where Baskin and Stahl described the enzyme localization. No staining was seen with pre-immune serum of the normal rabbit. We concluded that both the canine and rat choroid plexus are rich in Na+,K+-ATPase, which plays an important role in cerebrospinal fluid (CSF) secretion.

Animals↗
PubMed1984

Effects of the ratio of exogenous eicosapentaenoic acid to arachidonic acid on platelet aggregation and serotonin release.

We added arachidonic acid (AA) and eicosapentaenoic acid (EPA) to washed platelet suspensions in the absence of albumin, holding the total amount of the fatty acids constant at 2 microM, and changing the ratio of EPA to AA. Platelet aggregation, serotonin release and the amount of thromboxane (TX) B2, a cyclooxygenase product synthesized from exogenous AA, decreased as the ratio was increased. The decreases were greater than the expected ones from the diminution of the amount of exogenous AA. On the other hand, 12-hydroxyeicosatetraenoic acid (HETE), a lipoxygenase product synthesized from exogenous AA, increased in the presence of EPA. Although EPA was reported to be a poor substrate for platelet cyclooxygenase, the amount of TXB3 synthesized from exogenous EPA increased markedly by the simultaneous addition of AA. These results suggest that the EPA/AA ratio-dependent decrease in platelet aggregation and serotonin release is caused at least by both the decrease in the absolute amount of AA and the inhibitory effect of EPA on AA-metabolism via the cyclooxygenase pathway. Further studies on effects of EPA-metabolites via the cyclooxygenase pathway on platelet responses will be needed.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1984

Plasma carcinoembryonic antigen and acinar cell carcinoma of the pancreas.

Seventeen patients with histologically proven pancreatic cancers were studied in order to clarify the relationship of histologic types to plasma carcinoembryonic antigen (CEA) values. Two cases with marked elevation of plasma CEA values having 6100 ng/ml and 2500 ng/ml, respectively, disclosed histologically acinar cell carcinoma and mixed acinar and ductal cell carcinoma, respectively. Despite of massive hepatic metastases, the other 15 cases with ductal cell carcinoma, including 3 cases with cystadenocarcinoma, adenoacanthoma, and undifferentiated pancreatic cancer, respectively, showed normal or very modest elevation of plasma CEA values. No correlation was obtained between plasma CEA values and several biochemical tests. Two patients with marked elevation of plasma CEA value revealed strong staining in the cancerous areas of the pancreas by using a peroxidase-antiperoxidase staining technique. These findings suggest that acinar cell carcinoma of the pancreas may contribute to increase the circulating plasma CEA value.

Adenocarcinoma↗
PubMed1984

Follow-up study of a nation-wide neonatal metabolic screening program in Japan. A collaborative study group of neonatal screening for inborn errors of metabolism in Japan.

A nationwide neonatal screening program for phenylketonuria (PKU), maple syrup urine disease (MSUD), homocystinuria, histidinemia and galactosemia was started in Japan in 1977. The total number of infants screened had reached 6,311,754 by March, 1982. A follow-up study revealed the incidence of the disease in Japan: 1/108,823 for PKU; 1/450,840 for hyperphenylalaninemia (HPA); 1/1,577,939 for biopterin deficiency; 1/525,980 for MSUD; 1/1,051,959 for homocystinuria; 1/8,371 for histidinemia, and 1/788,969 for galactosemia type 1. The incidences of PKU, HPA, homocystinuria, and galactosemia (type 1) were found to be markedly low in Japan as compared with those in Caucasian countries. There was no great difference in the incidence of MSUD between both. On the other hand, the incidence of histidinemia was higher in Japan. It was found that most of the patients with PKU, HPA, MSUD, homocystinuria, or galactosemia are developing normally due to the early initiation of dietary treatment. These results clearly indicate that the neonatal mass screening program plays a great role in preventing the occurrence of handicapped children.

Biopterins↗