Action of Isoflurane on the Substantia Gelatinosa Neurons of the Adult Rat Spinal Cord

Background: Although isoflurane, a volatile anesthetic, can block the motor response to noxious stimulation (immobility and analgesia) and suppress autonomic responsiveness, how it exerts these effects at the neuronal level in the spinal cord is not fully understood.

Methods: The effects of a clinically relevant concentration (1 rat minimum alveolar concentration [MAC]) of isoflurane on electrically evoked and spontaneous excitatory/inhibitory transmission and on the response to exogenous administration of the [gamma]-aminobutyric acid type A receptor agonist muscimol were examined in lamina II neurons of adult rat spinal cord slices using the whole cell patch clamp technique. The effect of isoflurane on the action potential-generating membrane property was also examined.

Results: Bath-applied isoflurane (1.5%, 1 rat MAC) diminished dorsal root-evoked polysynaptic but not monosynaptic excitatory postsynaptic currents. Glutamatergic miniature excitatory postsynaptic currents were also unaffected by isoflurane. In contrast, isoflurane prolonged the decay phase of evoked and miniature [gamma]-aminobutyric acid type A receptor-mediated inhibitory postsynaptic currents and increased the amplitude of the muscimol-induced current. Isoflurane had little effect on action potential discharge activity.     

The results of an investigation of the various factors influencing the late patency ratio of coronary bypass grafting

The purpose of this communication was to find out the factors influencing the late patency ratio of coronary artery bypass grafts of 42 patients in our institution. The following results were obtained: 1. The size of the measured diameters of coronary arteries and the graft flow rates were correlated well to the late patency ratio (p less than 0.05). 2. The regular physical exercise trainings were significantly important to keep patent grafts (p less than 0.01). 3. In blood serum studies, serum uric acid levels were significantly lower (p less than 0.05), the average mean HDL cholesterol levels were much higher (p less than 0.001) and the ratio of total cholesterol to HDL cholesterol were significantly lower in the group with late patent grafts than with grafts occluded. Therefore, we found out the variables affecting graft patency ratio which were examined by a stepwise method were the diameter of the coronary artery, regular physical exercise training, the average of lower serum uric acid levels and higher HDL cholesterol levels. The multiple coefficient for these four variables was 0.562 (p less than 0.001) and the contribution was 31.6%. According to the base of this studies, we have concluded that postoperative regular physical exercise, low fat and restricted calorie intake were very important to keep the late patent grafts in long-term follow up period after coronary bypass surgery.     

ULTRASTRUCTURE OF AN ANAPLASTIC GIANT-CELL CARCINOMA FOUND 8 YEARS AFTER OPERATION ON A PAPILLARY CARCINOMA OF THE THYROID

Light and electron microscopic studies have been made on an anaplastic giant-cell tumor that developed in a woman 8 years after an operation on the thyroid for papillary carcinoma. Many giant cells were observed in the anaplastic tumor tissue, but no follicles. Numerous tightly-packed mitochondria and abundant ribosomes were present, but there were no desmosomes. The basement membrane was not distinct.     

Genetic alterations in thyroid carcinomas and adenomas detected by restriction landmark genomic scanning

Alterations of genomic DNAs in 9 papillary thyroid carcinomas and 3 follicular thyroid adenomas were examined by restriction landmark genomic scanning, a 2-dimensional gel analysis that allows detection of deletions, amplifications and other rearrangements of genomic DNA. DNAs from both thyroid tumors and associated non-tumorous glandular tissues were cleaved with the restriction enzyme NotI end-labeled with P-32 and size-fractionated by 2-dimensional electrophoresis using HinfI in a second digestion. The altered spots in carcinomas and adenomas were compared with those in nontumorous samples. Five and 4 spots were commonly amplified in carcinomas and adenomas, respectively. One amplified spot was apparently specific only for carcinoma and was not detected in any of adenomas examined. In contrast, 12 spots reduced in intensity were frequently observed in tumors, although a subset of 5 were more sporadically affected in adenomas. The results indicate both common and distinct genetic abnormalities occurring in thyroid tumors, which may relate to the different biological behaviors of malignant and benign neoplasms.     

Focal distribution of p16/CDKN2 gene mutations within individual prostate carcinomas

To examine the potential role of pl6/CDKN2 gene mutations in prostate tumorigenesis, focal areas within individual tumors were investigated. Eleven cases of histologically heterogeneous prostate carcinomas obtained by radical prostatectomy were subjected to analysis of p16/CDKN2 gene mutations. DNA was extracted from 5 to 10 separate areas of each tumor with different growth or histological patterns. Exons 1 through 3 of the p16/CDKN2 gene were amplified using the polymerase chain reaction (PCR) and screened for homozygous deletions and mutations of this gene by single-strand conformation polymorphism (SSCP) analysis. No homozygous deletions were observed in any of the prostate carcinomas, but two of the eleven tumors demonstrated mutations in exon 2 of p16/CDKN2 gene. Missense mutations were detected in only one and two foci, respectively, out of six ana ten selected tumor areas. The present results suggest that p16/CDKN2 gene mutations, although they occur at a low incidence, are involved in prostate tumorigenesis, indicating a mutational heterogeneity in addition to morphological heterogeneity.     

Wrapping operation for Stanford type A acute dissecting aneurysms]

Four cases of Stanford type A acute aortic dissection were treated by wrapping operation. After careful dissection between the dilated ascending aorta and right pulmonary artery, 8 mm woven Dacron vascular prosthesis was passed around the aorta and tightened. Further enforcement wrapping was carried out using several prostheses from aortic root to the innominate artery. We call this technique "wrapping operation". Emergent operations were performed on all patients because of cardiac tamponade, 6.8-33 hours after the onset of dissection. Three patients are doing well 17-39 months after the operation, but only 1 patient died early postoperative period because of DIC and multiple organ failure. And 2 patients was showed closure of entry of the ascending aorta by the postoperative aortography. We think that the wrapping operation is a useful technique for the patients of ruptured Stanford type A acute dissecting aneurysms.     

Protective Effects of a Hydrogen-Rich Preservation Solution in a Canine Lung Transplantation Model

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