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Biomedical subjects

M Mizuno

Publications and source records attributed to M Mizuno.

At least 541 records · Page 30Linked to original sources
PubMed1987

The experience of otolaryngological practice on neurological patients.

This paper summarizes the experiences of three years of otolaryngological practice at the Tokyo Metropolitan Neurological Hospital. Almost 30% of the patients treated were bedridden, necessitating otolaryngologists' ward visits. Neuro-otological examinations, other otolaryngological examinations and surgical treatments were accomplished. Neurology, neurosurgery and pediatric neurology have different purposes with regard to otolaryngological consultations. This study indicates that those varied demands are a problem in conducting effective otolaryngological practice. The study concluded that otolaryngologists could play a more important role in the diagnosis and treatment of patients with diseases of the central nervous system.

Female↗
PubMed1987

Serous otitis media in amyotrophic lateral sclerosis.

Serous otitis media (SOM) is a common disease, the cause of which is not always clear. In this paper authors report the high incidence of SOM among the patients with amyotrophic lateral sclerosis (ALS). Furthermore, a comparative study about ALS and other diseases shows higher incidence of SOM in ALS. Our study indicates that SOM in ALS seems to be mainly due to muscular disturbance of eustachian tube caused by ALS, although the influence of long term supine position and nasopharyngeal irritation by nasogastric feeding tube cannot be denied in the development of SOM.

Amyotrophic Lateral Sclerosis↗
PubMed1987

Neoplastic angioendotheliomatosis. Report of two autopsy cases with special reference to the origin of atypical cells.

Two autopsy cases of neoplastic angioendotheliomatosis (NAE) were presented. Both patients were elderly woman, characterized by an ascending progression of transverse myelopathy and abnormal brain shadows similar to metastatic tumor in computer tomographic examination in Case 1, and by typical clinical features of cerebral infarction in Case 2. Postmortem examinations of both cases revealed an exclusive intravascular distribution of large atypical cells in generalized organs, especially in the central nervous system, and associated multiple cerebral infarcts and, in Case 1, widespread demyelination of the spinal cord. There were no distinct lesions suggestive of a primary focus. In both cases only a few atypical cells were immunohistochemically positive for factor VIII-related antigen, likely due to non-specific absorption of serum factor VIII into the cells. On the other hand, almost all of the atypical cells were immunoreactive for LN-1, LN-2, and leukocyte common antigen, suggestive of lymphocytic (B cell) origin.

Aged↗
PubMed1987

Development of extrauterine fetal incubation system using extracorporeal membrane oxygenator.

Despite the recent progress in perinatal medicine, it is still difficult to manage the extremely immature newborn. A new extrauterine incubation system has been developed using 14 goat fetuses. The goat fetus is surrounded by artificial amniotic fluid and is connected to an extracorporeal membrane oxygenator. The blood is drained from the umbilical arteries and returned to the umbilical vein. The perfused blood is recirculated and ventilated with a mixture of O2, N2, and CO2 gases to obtain a PO2 of 30-35 mm Hg and a PCO2 of 30-35 mm Hg in the umbilical venous blood. Fetal heart rate, blood pressure, electroencephalogram, and several movement parameters are continuously recorded by the polygraph. With this system, the fetuses can be kept under fairly stable physiological conditions for periods up to 165 h. This improved system might therefore become a useful method to manage the ill fetuses and newborns.

Animals↗
PubMed1987

Monoclonal antibodies identifying antigens on distinct domains of rat hepatocytes.

To aid in evaluating the functional significance of various domains of the hepatocyte plasma membrane, we have developed monoclonal antibodies that react with three different antigens on the surface of rat hepatocytes. One antigen is present on the sinusoidal-lateral plasma membrane but is absent from the bile canalicular membrane. On the basis of apparent molecular weight and ability to bind a desialylated glycoprotein, this antigen may be the asialoglycoprotein receptor. It was also identified immunocytochemically on the sinusoidal-lateral plasma membrane of human hepatocytes. The second antigen is present only on the bile canalicular membrane, whereas the third is present on the entire cell surface of rat hepatocytes. Our monoclonal antibodies may be useful in investigations of the sorting mechanisms of hepatocyte membrane proteins and the pathogenesis of certain liver diseases.

Animals↗
PubMed1987

Cardiovascular responses at the onset of exercise with partial neuromuscular blockade in cat and man.

1. In decerebrated cats the cardiovascular, heart rate and blood pressure responses to static muscle contractions were followed from the onset of stimulation of the cut L7-S1 ventral roots. Heart rate and blood pressure were also followed during maximal voluntary and electrically induced static muscle contractions in man using one leg. In both cat and man contractions were performed under control conditions and tubocurarine-induced neuromuscular blockade. 2. In the cat, heart rate and blood pressure increased 1.7 s after the onset of the contraction. No cardiovascular responses were seen when the muscle contraction was blocked by tubocurarine. 3. In man, both heart rate and blood pressure increased at the onset of voluntary contractions. Partial curarization reduced strength to 39% of control. The heart rate response was unaffected by tubocurarine while the blood pressure response was reduced from 61 to 32 mmHg. 4. Electrical stimulation of the muscles resulted in 75% of voluntary strength in man. The heart rate response was delayed one R-R interval in the electrocardiogram but was as large as during voluntary contractions. During partial curarization the heart rate response was significantly smaller and the blood pressure response was reduced from 11 to 8 mmHg. 5. In conclusion, processes in active muscles elicit an increase in heart rate and blood pressure which depends on the intensity of the muscle contraction developed. However, the immediate cardiovascular responses at the onset of voluntary muscle contractions cannot be accounted for by reflexes generated in the working muscles alone.

Adolescent↗
PubMed1987

Effects of mitomycin C, 5-fluorouracil and cyclophosphamide on drug absorption, enzyme activities and mucosal lipid composition of intestine.

The effect of a single intravenous or oral administration of mitomycin C (MMC), 5-fluorouracil (5-FU) or cyclophosphamide (CP) on drug absorption was studied in rats in relation to changes in membrane characteristics. At 48 h after pretreatment, a differential effect on the absorption of sulfanilamide and L-tryptophan was observed in in situ recirculation experiments. Intravenous MMC administration suppressed the absorption of both sulfanilamide and L-tryptophan to a similar extent as a higher oral dose of this agent. Dosing with 5-FU via both routes caused the largest but almost equal suppression of L-tryptophan absorption. However, CP had no effect on the absorption of the two drugs. Differences in these effects were considered to reflect their pharmacological and pharmacokinetic properties. Absorption of drugs from the small intestine had a positive correlation with small intestinal wet weight regardless of the antitumor drug used, pretreatment doses and routes of administration and the results indicated that the change in absorptive surface area played a major role in this phenomenon. Toxicity to intestinal mucosa was shown to derive from an effect on dividing cells in the crypts because MMC and 5-FU preferentially decreased thymidine kinase activity. However, at the membrane level, increased mucosal membrane permeability was also confirmed by measuring the release rates of D-glucose from liposomes consisting of mucosal total lipids obtained from the antitumor drug-treated rats. Pretreatment with lipophilic and polymeric prodrugs of MMC did not exhibit any effect on drug absorption and thus, the possibility of alleviation of toxicity and adverse reactions via the prodrug approach was suggested.

Animals↗
PubMed1987

The inhibitory effect of cytosolic fraction of human decidua on prostaglandin synthesis.

To elucidate the mechanism of suppression of prostaglandin (PG) production in decidua in early pregnancy, the PG synthetase activity of decidua and mid-secretory endometrium was studied. The microsomal fractions and their supernatants were prepared from the tissue by ultracentrifugation at 105,000 g. The standard incubation mixture consisted of the microsomal fraction and 14C arachidonic acid with cofactors, with incubation being carried out for 10 minutes at 37 degrees C. After extraction, the radioactivity of PGE2 was measured and PG synthetase activity was assayed. The apparent Km value for PG synthetase in decidua was 4.6 +/- 0.14 x 10(-6) M (n = 4), whereas that in endometrium was 4.6 +/- 1.18 x 10(-6) M (n = 3). Subsequently, kinetic studies on PG synthetase inhibitor in decidua were carried out. When sheep seminal vesicle was used as an enzyme source, the decidual supernatant showed competitive inhibition. The inhibitory substance in decidua was inactivated after incubation for 15 minutes at 65 degrees C. It seems likely that the suppression of PG biosynthesis in human decidua in early pregnancy is not due to the difference in PG synthetase found in decidua and in endometrium, but due to the existence of PG synthetase inhibitor in decidua.

Cell Extracts↗
PubMed1987

[A study on the activity of the PGI2 producing enzyme system derived from maternal and fetal vessels of toxemia of pregnancies].

We investigated the conversion rate from arachidonic acid (A.A.) to PGI2 and the activity of PGI2 producing enzyme system in endothelial cells of umbilical veins (U.V.) and maternal omental veins (O.V.) in normal pregnancy (NOR) and toxemia of pregnancy (TOX). The conversion rate from A.A. to PGI2 for U.V. and O.V. in NOR was higher than that in TOX. There was a significant difference between NOR and TOX with the conversion rate for U.V. at a concentration of 172.4 nM/ml A.A. The apparent Vmax value for PGI2 producing enzyme system (nM/mg) in U.V. in NOR (n = 7) was 0.88 +/- 0.21 (mean +/- S.E.) and that for TOX (n = 3) was 1.63 +/- 0.18. The apparent Km value for the enzyme system (microM) in U.V. in NOR (n = 7) was 0.75 +/- 0.25, and that for TOX (n = 3) was 3.26 +/- 0.78. Significant differences (p less than 0.05) between NOR and TOX were observed with Vmax and Km values. The apparent Vmax value for the enzyme system in O.V. in NOR (n = 3) was 0.32 +/- 0.13, and that for TOX (n = 3) was 2.12 +/- 0.38. The apparent Km value for the enzyme system in O.V. of NOR (n = 3) was 0.26 +/- 0.06, and that for TOX (n = 3) was 0.97 +/- 0.09. There was a significant difference between (p less than 0.05) the Vmax and Km values for NOR and TOX. The present study showed that U.V. (fetal vessel) and O.V. (maternal vessel) in TOX had a lower activity PGI2 producing enzyme system than those in NOR due mainly to an imbalance between the substrate supply and cyclooxygenase activity.

Adult↗
PubMed1987

Cobalamin-binding protein in gastric juice as a new tumor marker in gastric cancer.

Cobalamin-binding protein (binder) in gastric juice was studied as a biochemical marker of gastric cancer. Fasting gastric juice of cancer patients and controls with benign disease was used for separation of cobalamin binders by gel filtration and DEAE-cellulose column chromatography. Physicochemical properties of the binder in gastric cancer patients were shown to have a larger molecular size and more acidic isoelectric point than the control binder. The binder was found in the gastric juice of all patients with early gastric cancer. Detection of the binder may be clinically valuable as a possible marker in the diagnosis of gastric cancer.

Chromatography, DEAE-Cellulose↗
PubMed1986

Changes in D-glucose uptake by brush-border vesicles from small intestine of rats treated with mitomycin C.

The effect of mitomycin C pre-administration on the D-glucose transport system in the intestinal brush-border membrane of rat small intestine was examined by a rapid filtration technique. Forty-eight hours following the intravenous administration of mitomycin C, there were extensive and severe mucosal derangements. At this time point, membrane vesicles were prepared from the mitomycin-C-pretreated and control rats. Binding studies indicated that D-glucose entered into the intravesicular space of vesicles even in the case of mitomycin-C-pretreated rats. Vesicles obtained from both the mitomycin-C-pretreated and the control rats showed sodium-dependent uptake of D-glucose, but the initial uptake at 15 sec was significantly greater in control rats than in mitomycin-C-pretreated rats. Comparison of kinetic parameters of D-glucose transport indicated that Km was not significantly different between control and mitomycin-C pretreated rats. The pretreatment with mitomycin C decreased Vmax and increased the diffusional permeability to D-glucose considerably. These changes induced by mitomycin C seemed to derive not from a direct effect on mature enterocytes but from an indirect effect secondary to mitotic inhibition in the crypts.

Animals↗
PubMed1986

Enzymatic bases for the fatty acid positioning in phospholipids of Brevibacterium ammoniagenes.

Positional distribution of fatty acids in phospholipids from Brevibacterium ammoniagenes was analyzed to find that phosphatidylethanolamine consisted mainly of 1-saturated acyl 2-unsaturated acyl species while phosphatidylglycerol consisted mainly of 1-unsaturated acyl 2-saturated acyl species. Three acyltransferase systems were characterized in a membrane preparation--the acylations of glycerophosphate, 1-acyl-glycerophosphate, and 2-acyl-glycerophosphate--which appeared to be catalyzed by different enzymes. The distribution of fatty acids in the phosphatidylethanolamine molecule was not correlated simply with the specificities of these enzymes, but the relatively high specificity for palmitoyl-CoA of the glycerophosphate acyltransferase system to form 2-acyl-glycerophosphate, followed the relatively high specificity for oleoyl-CoA of the 2-acyl-glycerophosphate acyltransferase system, provided a basis for producing the major molecular species of phosphatidylglycerol.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗