Search PubMed⌕ Search

Biomedical subjects

R Nishikawa

Publications and source records attributed to R Nishikawa.

44 records · Page 3Linked to original sources

[Ependymal cyst--case report].

An eleven-month-old male infant with an ependymal cyst is reported. He was born after full-term pregnancy and vacuum extraction. His growth and development was somewhat retarded and he could control his head at the age of five months. He was admitted to our hospital because of the enlargement of his head and the paretic right upper limb. On admission he was found to be a well-nourished infant with the head circumference of 54.5 cm and the height of 75.5 cm. Physical examination disclosed slight weakness in the right upper extremity but no signs of increased intracranial pressure. Computed tomography (CT) revealed a huge low density area in the left frontoparietooccipital region which extended to the right across the midline. Another low density area was seen in the quadrigeminal cistern. CT findings also suggested an association with agenesis of the corpus callosum. The huge supratentorial cyst was isolated from the ventricles and subarachnoid space, which was shown by administration of metrizamide into the cyst. Carotid angiograms showed displacement of both anterior cerebral arteries to the right, which were dissociated from each other. This fact and an association with agenesis of the corpus callosum supported the idea that the cyst originiated in the interhemispheric fissure and expanded into both hemispheres. Cyst fluid was watery clear and protein and sugar contents were 13 mg/dl and 56 mg/dl respectively. The patient underwent a left frontal craniotomy and partial removal of the cyst wall was performed to make a communication with the ventricle. His postoperative course was uneventful and the weakness of the right upper extremity gradually improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Agenesis of Corpus Callosum↗

Endogenous type-C viral expression during lymphoma development in irradiated NFS mice.

The expression of the type-C retrovirus and the virus-related components in NFS mice were examined during preleukemic and leukemic phases after fractionated whole-body X irradiation. The NFS mice were highly susceptible to induction of thymoma by fractionated X irradiation. The leukemic tissues were negative for infectious type-C virus, as detected by both the XC-plaque test and mink S+ L- focus-inducing assays, but contained a substantially higher level of viral-specific RNA-dependent DNA polymerase activity and a major core protein p30 than the corresponding tissues from unirradiated age-control mice. In the preleukemic phase, the amount of p30-related antigen increased transiently in spleen. The leukemic cell lines established from radiation-induced lymphomas produced particulate entities with a buoyant density of about 1.15 g/ml. These virus-like particles lacked in vitro infectivity to mouse cells and mink lung cells and leukemogenicity in syngeneic mice. The p30-related antigens of these particles were immunologically similar to that of xenotropic virus derived from NZB mouse.

Animals↗

Disposition of total and unbound prednisolone in renal transplant patients receiving anticonvulsants.

Kidney transplant patients receiving phenytoin or phenobarbital may have decreased graft survival. These drugs have been shown to enhance the metabolism of glucocorticoids. We determined the disposition of total and unbound prednisolone in six stable kidney transplant patients receiving prednisone for immunosuppression and phenytoin or phenobarbital for a seizure disorder. Six similar patients not on anticonvulsants served as controls. A single intravenous dose of prednisolone was administered, and plasma samples were analyzed for prednisolone using a high-performance liquid chromatographic assay. Equilibrium dialysis was used to determine unbound prednisolone concentrations. Pharmacokinetic analysis showed that the half-life of prednisolone was shorter in the anticonvulsant group compared to the controls, based on both total (2.3 +/- 0.4 vs. 3.4 +/- 0.2 hr (SD), P less than 0.01) and unbound (1.7 +/- 0.3 vs. 2.4 +/- 0.2 hr, P less than 0.01) concentrations. Total drug clearance was 10.4 +/- 2.8 liters/hr (0.171 +/- 0.087 liters/hr X kg) in the anticonvulsant group versus 7.2 +/- 1.2 liters/hr (0.100 +/- 0.014 liters/hr X kg) in the controls (P less than 0.05). Unbound prednisolone clearance was 57.2 +/- 12.1 versus 46.4 +/- 8.7 liters/hr (P greater than 0.05) and for weight-corrected estimates 0.886 +/- 0.224 liters/hr X kg versus 0.644 +/- 0.115 liters/hr X kg (P less than 0.05) in the two groups, respectively. Thus, the disposition of prednisolone is altered by anticonvulsants in kidney transplant patients and may require dose alteration.

Adolescent↗

Irrigation of the peritoneal cavity and local antibiotics in the treatment of peritonitis.

Peritonitis was induced in the Sprague-Dawley rats by the implantation of gelatin capsules containing 0.3 milliliter of human fecal suspension into the peritoneal cavity. The rats were then treated with systemic antibiotics or peritoneal irrigation with normal saline solution alone or cephalotin solution, 2,000 micrograms per liter, or both. The results show that peritoneal irrigation with normal saline solution or with cephalotin alone was ineffective, even though the cephalotin concentration used inhibited the growth of all bacterial species isolated during the free stage of peritonitis in vitro. Systemic antibiotics alone as well as in combination with peritoneal irrigation significantly improved the survival rate, p less than or equal to 0.05 and p less than or equal to 0.02, respectively. However, only systemic antibiotics in combination with peritoneal irrigation resulted in a significant cure rate compared with the control group and the group treated with systemic antibiotics alone, p less than or equal to 0.002. There was no increase in the cure or survival rates when antibiotics were added to the peritoneal irrigation fluid. In the second experiment, seven of ten rats treated with systemic antibiotics survived, but only two rats had no intraperitoneal abscesses at autopsy. Intraperitoneal application of antibiotics did not improve these results: six rats survived, and one rat was cured. We conclude that peritoneal irrigation alone is ineffective in the treatment of peritonitis. The addition of peritoneal irrigation to systemic antibiotic therapy, however, resulted in a significantly increased cure rate. The addition of antibiotics to the irrigant does not further improve the results, and local antibiotics are not more effective than systemic antibiotics. We believe that benefit of peritoneal irrigation is due to its mechanical effect.

Animals↗