Biomedical subjects

O Watanabe

Publications and source records attributed to O Watanabe.

149 records · Page 9Linked to original sources

PubMedDate not supplied

Experimental regional cerebral ischemia in the middle cerebral artery territory in primates. Part 2: Effects on brain water and electrolytes in the early phase of MCA stroke.

Acute regional cerebral ischemia was produced in the middle cerebral artery (MCA) territory in monkeys (Macaca mulatta) by selective embolization of the internal carotid (ICA) bifurcation with minimum surgical intervention in the neck under sedated conditions. Two of five hours after embolization, brain water (measurement of dry weight) and tissue concentration of sodium and potassium were determined in the tissues of the sylvian cortex, putamen and subcortical white matter in the affected MCA territory. As early as three hours, initial increase in brain water was detected in the samples of the putament without noticeable change in tissue electrolytes in two of three animals. Gross ischemic swelling of the gray matter, in both the sylvian cortex and putamen, became obvious in six of eight animals after four to five hours. This swollen gray matter showed marked increase in brain water (up to 36% swelling), increase in tissue sodium (up to 100% of the control value), and decrease in tissue potassium (down to 55%). On the other hand, edema in the white matter, if present at all, was minimal without detectable change in tissue electrolytes and was always accompanied by much greater ( greater than two to seven times) edema in the gray matter. Thus, the gray matter edema, in both the deep subcortical structures and the cortex, appeared to play the major role in the development of hemispheric swelling of the brain which may begin within hours of the onset of the MCA stroke in monkeys. Microscopically, the swollen gray matter which showed more than 10% swelling with a definite shift of tissue sodium and potassium content appeared to be dead tissue. However, early edema in the gray matter which showed less than 10% swelling without detectable change in electrolytes might be caused by simple diffusion of water through the dysfunctional capillary wall or cell membrane with or without a permeability gradient between the intravascular cerebrospinal fluid and cerebral tissue compartment and might possibly be reversible.

Animals↗

PubMedDate not supplied

Anemia and neutropenia due to copper deficiency in enteral nutrition.

Copper deficiency has been regarded a rare complication of total parenteral nutrition. This report describes the first known case of anemia and neutropenia caused by copper deficiency in a patient receiving long-term enteral nutrition. A 34-year-old man presented with bulbar palsy and tetraplegia after an operation for cerebellar hemorrhage on June 7, 1989. Nasopharyngeal tube feeding with a defined-formula diet (Besvion) was instituted on June 19, 1989. He developed normocytic anemia and neutropenia approximately 19 months after the initiation of the tube feeding. Serum copper and ceruloplasmin levels were markedly below normal. There were anisocytosis and erythrocyte deformities in the peripheral blood smear. Bone marrow aspirates revealed a hypocellular marrow with numerous myeloid and erythroid cells with cytoplasmic vacuoles. Because the amount of copper administered was estimated to be 2.6 to 5.1 mumol/d during the tube feeding, copper deficiency was suspected to be the cause of the hematologic disorders. The patient's daily oral copper intake was increased to 34 mumol/d. His serum copper and ceruloplasmin concentrations reached a normal level after 16 days and 23 days of copper supplementation, respectively. A marked reticulocytosis occurred after 10 days of copper supplementation, and his anemia gradually improved over the next 3 months. His blood neutrophil count also returned to normal within 2 weeks.

Adult↗

PubMedDate not supplied

Antitumor efficacy of combination chemotherapy with UFT and cyclophosphamide against human breast cancer xenografts in nude mice.

The combination of cyclophosphamide (CPA) and 5-fluorouracil (5-FU) is currently regarded as the most effective therapy for the treatment of patients with advanced and recurrent breast cancer. We evaluated the augmentation of antitumor activity and toxicity by coadministration of CPA and UFT (1M tegafur--4M uracil) instead of intravenous 5-FU on H-31 human breast cancer xenografts in nude mice. The maximum tolerable dose (MTD) of UFT alone (24 mg/kg) and CPA alone (85 mg/kg) had a significant effect on H-31 tumors in mice with 86.6% and 83.0% inhibition rates of tumor growth, respectively, and without loss of body weight, diarrhea or myelosuppression. The combined administration with full and 83.3% MTD of UFT and CPA augmented the antitumor activity compared to that of UFT alone and CPA alone. The relative tumor volume of the UFT plus CPA-treated group to the UFT- and CPA-treated groups was 0.28 and 0.36 for the full MTD, and 0.51 and 0.67 for 83.3% MTD, respectively. When CPA was consecutively administered to the tumor-bearing mice for 14 days, there were no decreases in the activities of enzymes related to 5-FU metabolism, but there was an significant increase in the activity of ribonucleotide reductase, suggesting that anabolism of 5-FU derived from tegafur is accelerated to some extent by coadministration of CPA. In conclusion, these results suggest that combination therapy with oral UFT and CPA may be useful for the long-term treatment of cancer patients with advanced and recurrent breast cancers.

Animals↗

PubMedDate not supplied

Computed tomographic appearance of closed-loop obstruction.

The obstruction of a bowel segment at two points results in closed-loop obstruction, and is apt to cause strangulation. Thus, the early recognition of closed-loop small bowel obstruction might reduce the mortality rate. However, plain films are limited in their ability to diagnose it. Using previously described criteria, we retrospectively reviewed the CT images of six surgically confirmed cases of closed loop obstruction. In all patients, CT showed the characteristic configuration of closed loops, specific findings detected at the site of obstruction, or both. On the basis of our experience, CT is a useful, non invasive method for the investigation of patients with suspected closed-loop obstruction.

Adult↗

PubMedDate not supplied

Central neurocytoma with clinically malignant behavior.

We describe two cases of central neurocytoma that did not show histopathologic features of anaplasia but did show tumor dissemination after surgery and radiation therapy. CT and MR imaging before surgery depicted extraventricular extension of the tumors. The importance of radiologic findings is stressed.

Adult↗