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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 595 records · Page 33Linked to original sources
PubMed1991

[A case of meningioangiomatosis in an infant].

We report here a rare case of meningioangiomatosis in an infant, not associated with von Recklinghausen's disease. A 14-month-old female was admitted because of seizures. Neurological findings on admission were normal. Computed tomography showed a slightly high density mass with marked contrast enhancement in the left temporoparietal lobe. Magnetic resonance image (MRI) revealed a slightly hypointensive lesion surrounded by an isointensive band on T1-weighted image, and a hyperintensive lesion surrounded by a slightly hypointensive band on T2-weighted image. Brain edema was shown to a certain extent around the lesion on MRI. Left carotid angiography demonstrated a slightly upward shift of the left middle cerebral artery, but no abnormal vascularity was shown. A temporoparietal craniotomy was performed. A yellowish red, elastic soft tumor was observed in the left temporal lobe. The tumor resembled hyperemic hypertrophic gyri and was well demarcated. Total removal of the tumor was performed. Pathological diagnosis was meningioangiomatosis. The patient is still doing well 3 years and 5 months after the operation. There was no evidence of recurrence on computed tomography at the 3-year follow up. She didn't have any stigmata, such as café au lait spots or neurofibromas suggesting von Recklinghausen's disease.

Angiomatosis↗
PubMed1991

[A case of effective preoperative chemotherapy in alveolar soft part sarcoma].

Alveolar soft part sarcoma is primarily treated by surgery, and reports of effective chemotherapy have been infrequent. We experienced a patient with alveolar soft part sarcoma in the left thigh, in whom preoperative chemotherapy with cisplatinum (CDDP) and adriamycin (ADM) was effective. This patient was a 13-year-old male who had an elastic hard mass with the size of his fist in the medial thigh. Plain X-ray revealed bone destruction with periosteal reactions in the distal diaphysis of the femur. Biopsy specimen showed alveolar growth of relatively large cells with eosinophilic or clear cytoplasm. PAS staining was positive in microgranular patterns in part of the cells, but no crystalline structure were observed. A diagnosis of alveolar soft part sarcoma was made, and chemotherapy was started. After administration of 150 mg of CDDP intraarterially twice and 50 mg of ADM intravenously 5 times, effectiveness of chemotherapy was estimated by physical and radiological findings. In the resected specimen, the margins of the soft part tumor showed shell-like ossification, suggesting the subperiosteal or intraosteal origin. Histology of the removed specimen showed that the tumor was mostly replaced by fibrous tissues, indicating the effectiveness of the preoperative chemotherapy. This disease has a relatively long course, however, the present case is considered to be another exceptional case that responded to preoperative chemotherapy.

Adolescent↗
PubMed1991

[Modified operation for an early stage gastric cancer].

The standard operation for gastric cancer is carried out for advanced gastric cancer with serosal invasion accompanying patent disseminative metastasis to the peritoneum of the omental bursa and lymph node metastases. It consists of subtotal or total gastrectomy, omentobursectomy and extended lymph node dissection. An early stage cancer, which in Japan accounts for almost a half of the resectable cases of gastric cancer, shows no serosal invasion, and lymph node metastases are rare if the cancer remains intramucosal. Such cases represent about a half the cases of the early stage cancer. The diagnosis of the early stage cancer, especially if it remains intramucosal, is made by means of preoperative radiological and endoscopic examinations and intraoperative examination. Since 1977 we have been performing a modified operation as well for cases of the early stage cancer. The surgical procedure is as follows: reduction in the size of gastric resection by 2/3, pylorus-preserving gastrectomy and proximal gastric resection; preservation of the distal portion of the greater omentum and transverse incision of the upper abdomen instead of upper midline incision to prevent ileus due to intestinal adhesion to abdominal wound around umbilicus; sparing bursectomy; narrowing the area of lymph node dissection; sparing thoracotomy for cancer in the esophagogastric junction; sparing splenopancreatectomy; preservation of the hepatic branch of the vagal nerve and postoperative temporary oral administration of cholagogue to prevent postgastrectomy cholelithiasis. In addition, the primary lesion is isolated from the blood circulation by means of ligation of the drainage veins to diminish metastasis through the blood vessels (hepatic metastasis, etc.), which is the main cause recurrence after surgery for the early stage cancer. The results of this new surgery are satisfactory; the five-year postoperative survival rate is 100.0% and it reduced the time needed for surgery, anesthesia and blood transfusion.

Humans↗
PubMed1990

Activation of a brain type Na pump after glutamate excitation of cerebral neurons.

Rat cerebral neurons matured in culture were stimulated with glutamate, and the effects of glutamate on the activities of the Na pump isoforms were investigated. Glutamate increased the total Na pump activity via a remarkable increase in the activity of the brain type (highly digitalis-sensitive) isoform and a slight decrease in the common type (weakly digitalis-sensitive) isoform activity. The effects of glutamate were produced in response to an enhancement of [Na+]i in the neurons, which resulted from passive Na+ influx through glutamate receptor-mediated cation channels. These results suggest that the Na pump isoforms in neurons differ in their physiological significance and that the brain type isoform plays an important role in restoring concentration gradients of Na+ and K+ after neuronal excitation.

Animals↗
PubMed1990

Insulin-like growth factor I (IGF-I) distribution in the tissue and extracellular compartment in different regions of rat brain.

The regional distribution of insulin-like growth factor I (IGF-I) was examined in the tissue and extracellular compartment of rat brain. The tissue content of IGF-I was the highest in the pituitary gland, followed by the olfactory bulb, upper brainstem, cerebellum, striatum, hippocampus, lower brainstem, and cerebral cortex. The extracellular concentration was studied by intracerebral microdialysis technique, and the highest content was found in the hippocampus, followed by the olfactory bulb, hypothalamus, cerebellum, striatum, and cerebral cortex. The tissue and extracellular contents were significantly correlated in the olfactory bulb, hypothalamus, cerebellum, striatum, and cerebral cortex. IGF-I might act by paracrine and/or autocrine regulatory mechanisms in these regions.

Animals↗
PubMed1990

Enzymic synthesis of useful chito-oligosaccharides utilizing transglycosylation by chitinolytic enzymes in a buffer containing ammonium sulfate.

A chitinase purified from culture filtrates of Trichoderma resei KDR-11 efficiently catalyzed a transglycosylation reaction on tetra-N-acetylchitotetraoside in a buffer medium containing ammonium sulfate, converting the tetrasaccharide into hexa-N-acetylchitohexaose (39.6%) and di-N-acetylchitobiose (55.7%) as the major products. Sugar-chain elongation from di-N-acetylchitobiose as the initial substrate to hexa-N-acetyl-chitohexaose and hepta-N-acetylchitoheptaose was also efficiently induced through lysozyme catalysis in the presence of ammonium sulfate at high (30%) concentration. In this case, the addition of ammonium sulfate to the reaction system resulted in a remarkable increase of the hexamer and heptamer productions, which are desirable as biologically active oligosaccharides.

Acetylglucosamine↗
PubMed1990

Enzymatic synthesis of p-nitrophenyl 3(5)-O-beta-N-acetylglucosaminyl-alpha-maltopentaoside by lysozyme; a novel substrate for human amylase assay.

Transglycosylation from di-N-acetylchitobiose to the 3-position at the nonreducing end glucosyl group of p-nitrophenyl alpha-maltopentaoside was regioselectively induced through the use of hen egg-white lysozyme. The enzyme formed p-nitrophenyl 3(5)-O-beta-N-acetylglucosaminyl-alpha-maltopentaoside (5% of the enzyme-catalyzed net decrease of p-nitrophenyl alpha-maltopentaoside) from di-N-acetylchitobiose as a donor and p-nitrophenyl alpha-maltopentaoside as an acceptor. The rate of the transglycosylation depended on the concentration of substrate, the temperature and the pH. The hydrolytic actions of human pancreatic and salivary alpha-amylase on this derivative were examined. The maltopentaoside derivative was shown to be useful as a substrate for alpha-amylase assay through a coupled reaction involving alpha-D-glucosidase and glucoamylase.

Acetylglucosamine↗
PubMed1990

Hydrolysis of beta-D-glucopyranosyl fluoride to alpha-D-glucose catalyzed by Aspergillus niger alpha-D-glucosidase.

Aspergillus niger alpha-D-glucosidase, crystallized and free of detectable activity for beta-D-glucosides, catalyzes the slow hydrolysis of beta-D-glucopyranosyl fluoride to form alpha-D-glucose. Maximal initial rates, V, for the hydrolysis of beta-D-glucosyl fluoride, p-nitrophenyl alpha-D-glucopyranoside, and alpha-D-glucopyranosyl fluoride are 0.27, 0.75, and 78.5 mumol.min-1.mg-1, respectively, with corresponding V/K constants of 0.0068, 1.44, and 41.3. Independent lines of evidence make clear that the reaction stems from beta-D-glucosyl fluoride and not from a contaminating trace of alpha-D-glucosyl fluoride, and is catalyzed by the alpha-D-glucosidase and not by an accompanying trace of beta-D-glucosidase or glucoamylase. Maltotriose competitively inhibits the hydrolysis, and beta-D-glucosyl fluoride in turn competitively inhibits the hydrolysis of p-nitrophenyl alpha-D-glucopyranoside, indicating that beta-D-glucosyl fluoride is bound at the same site as known substrates for the alpha-glucosidase. Present findings provide new evidence that alpha-glucosidases are not restricted to alpha-D-glucosylic substrates or to reactions providing retention of configuration. They strongly support the concept that product configuration in glycosylase-catalyzed reactions is primarily determined by enzyme structures controlling the direction of approach of acceptor molecules to the reaction center rather than by the anomeric configuration of the substrate.

Aspergillus niger↗
PubMed1990

Simultaneous determination of butyltin and phenyltin compounds in oysters by capillary gas chromatography.

A method is described for the simultaneous determination of butyl- and phenyltin compounds in oyster samples. The organotin compounds were extracted (as chlorides) from oyster homogenates with hydrochloric acid and benzene in the presence of 0.05% tropolone. These compounds were converted into pentyl derivatives with pentyl Grignard reagent and then analysed by capillary gas chromatography with a flame photometric detector equipped with a 393-nm filter. The recoveries of six organotin compounds added to oyster samples ranged from 71 to 74%. The detection limits of butyl- and phenyltin compounds were in the 5-9 pg range as tin. We detected significant amounts of three organotin compounds (di- and tributyltin and triphenyltin) in oyster samples.

Animals↗
PubMed1990

Doppler echocardiographic-determined changes in left ventricular diastolic filling flow velocity during the lower body positive and negative pressure method.

Changes in parameters of left ventricular (LV) diastolic filling flow obtained with Doppler echocardiography during the lower body positive and negative pressure method were analyzed in 15 patients (12 with coronary artery disease and 3 with dilated cardiomyopathy). Lower body pressure was altered at 5 steps (+20, +10, 0, -20 and -40 mm Hg vs atmospheric pressure). Pulmonary capillary wedge pressure measured with a balloon-tipped catheter was changed proportionally with lower body pressure during the procedures (p less than 0.01). Mean systemic arterial pressure was changed slightly during lower body positive pressure and negative pressure of -40 mm Hg. Heart rate was almost unchanged except at lower body pressure of -40 mm Hg. The peak velocity of LV early diastolic filling flow was changed with pulmonary capillary wedge pressure in an almost parallel fashion during the procedures (p less than 0.01). The peak velocity of LV late diastolic filling flow showed smaller changes than that of early diastolic filling flow. Changes in pulmonary capillary wedge pressure correlated positively with changes in the peak velocity of LV early diastolic filling flow (r = 0.759, p less than 0.01), but not with changes in the peak velocity of LV late diastolic filling flow (r = 0.039, not significant) during lower body negative pressure of -20 mm Hg. These data suggest that left atrial pressure is one of the important determinants of LV early diastolic filling flow in this acute clinical setting and that LV late diastolic filling flow is less sensitive to changes in left atrial pressure than LV early diastolic filling flow.

Adult↗
PubMed1990

Removal of famotidine by haemodialysis in elderly anuric patients.

The effect of haemodialysis on the pharmacokinetics of oral famotidine has been studied in five elderly anuric patients. Famotidine 20 mg was administered in a cross-over design to patients on and not on haemodialysis. The elimination rate constant of haemodialysis (k) was 4.6-fold larger than the systemic elimination rate constant (ke). Although the mean maximum serum concentration of famotidine during haemodialysis (141.5 ng.ml-1) was not significantly lower than that without haemodialysis (195.6 ng.ml-1), the AUC up to 5 h during haemodialysis was significantly decreased to 58.1% of the value without it. The data suggest that famotidine is dialysable by haemodialysis.

Aged↗
PubMed1990

Allosteric properties, substrate specificity, and subsite affinities of honeybee alpha-glucosidase I.

The substrate specificity of honeybee alpha-glucosidase I, a monomeric enzyme was kinetically investigated. Unusual kinetic features were observed in the cleavage reactions of sucrose, maltose, p-nitrophenyl alpha-glucoside, phenyl alpha-glucoside, turanose, and maltodextrin (DP = 13). At relatively high substrate concentrations, the velocities of liberation of fructose from sucrose, glucose from maltose, p-nitrophenol from p-nitrophenyl alpha-glucoside, and phenol from phenyl alpha-glucoside were accelerated, and so the Lineweaver-Burk plots were convex, indicating negative kinetic cooperativity: the Hill coefficients were calculated to be 0.50, 0.64, 0.50, and 0.67 for sucrose, maltose, p-nitrophenyl alpha-glucoside, and phenyl alpha-glucoside, respectively. For the degradation of turanose and maltodextrin, the enzyme showed a sigmoidal curve in v versus s plots and thus catalyzed the reaction with positive kinetic cooperativity. The Lineweaver-Burk plots were concave and the Hill coefficients were 1.2 and 1.5 for turanose and maltodextrin, respectively. These unique properties cannot be interpreted by the reaction mechanism that Huber and Thompson proposed: (1973) Biochemistry 12, 4011-4020. The rate parameters for the hydrolysis of sucrose, maltose, p-nitrophenyl alpha-glucoside and phenyl alpha-glucoside were estimated by extrapolating the linear part of the Lineweaver-Burk plots at low substrate concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Allosteric Regulation↗
PubMed1990

Acute hemodynamic effects of nilvadipine, a new calcium channel blocker, in patients with congestive heart failure.

The acute hemodynamic effects of nilvadipine, a newly synthesized calcium channel blocker, were studied in 12 patients with congestive heart failure. Hemodynamic measurements were made before and 15, 30, and 60 min after oral administration of 6 mg nilvadipine. Substantial reductions in systemic vascular resistance (-28.8 +/- 6.3%, p less than 0.01) and forearm vascular resistance (-52.0 +/- 6.2%, p less than 0.01) after nilvadipine administration were associated with increases in cardiac index (31.1 +/- 8.3%, p less than 0.01) and forearm blood flow (105.2 +/- 27.4%, p less than 0.01). Mean arterial and pulmonary arterial pressures were decreased by 12.2 +/- 3.0% (p less than 0.01) and 14.7 +/- 5.0% (p less than 0.05), respectively, after nilvadipine administration; however, heart rate remained unchanged. Decreases in mean arterial pressure correlated with the baseline arterial pressure (y = 0.58x - 41.6, r = 0.75, p less than 0.01). Pulmonary capillary wedge pressure decreased by 33.1 +/- 9.1% (p less than 0.01) after nilvadipine administration. However, right atrial pressure and the venous stiffness constant remained unchanged, and the venous pressure-volume curve was not shifted significantly. Therefore, the decrease in pulmonary capillary wedge pressure was attributed primarily to afterload reduction. Nilvadipine holds promise as a vasodilator for the therapy of congestive heart failure.

Aged↗
PubMed1990

Complications of lateral C1-2 puncture myelography.

This study reviewed the technical complication of 112 cases of lateral C1-2 puncture myelography for cervical spinal cord disorders. Spinal cord puncture and contrast injection, puncture between the occiput and C1, and blood vessel puncture were the main complications. These principally depended on the positioning of the patient's neck (hyperextension) and misdirection of the x-ray beam. For preventing major arterial puncture, the authors also reviewed 164 vertebral angiograms and determined the pathway of the vertebral arteries and the incidence of anomaly.

Female↗
PubMed1990

Antimicrobial activity and stability to beta-lactamase of BMY-28271, a new oral cephalosporin ester.

BMY-28271, the acetoxyethyl ester of BMY-28232, 7-[(Z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3(Z) -propen-1-yl-3- cephem-4-carboxylic acid, is a new oral cephalosporin. BMY-28232 has a widely expanded spectrum with high activity against gram-positive and gram-negative bacteria. BMY-28232 is far more active than cefixime or cefteram against Staphylococcus aureus and Staphylococcus epidermidis. Against gram-negative bacteria, the activity of BMY-28232 was comparable to or somewhat weaker than that of cefixime or cefteram. BMY-28232 was a poor substrate for various beta-lactamases. Orally administered BMY-28271 had a good therapeutic effect on systemic infections with S. aureus and some gram-negative bacteria in mice. Oral BMY-28271 was efficacious against S. aureus Smith infection: the efficacy of BMY-28271 was 80 to 90 times higher than that of cefixime or cefteram.

Administration, Oral↗