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Biomedical subjects

T Ohira

Publications and source records attributed to T Ohira.

At least 19 recordsLinked to original sources
PubMed1992

[Induction of tumor immunity by cytokine cDNA transfected Lewis lung carcinoma].

It is difficult to induce anti-tumor immunity in tumors with low antigenicity. In order to develop a more effective method of immunotherapy, we transfected interleukin-2 (IL-2), interleukin-4 (IL-4) and interleukin-6 (IL-6) genes into Lewis lung carcinoma (LLC) cells. Then, 1 x 10(6) LLC-IL-2, LLC-IL-4 or LLC-IL-6 cells were transplanted into C57BL/6 mice subcutaneously. All mice transplanted with LLC-IL2 and half those with LLC-IL-4 rejected the tumor cells. Survival time of LLC-IL-6 transplanted mice was significantly shorter than that of LLC transplanted mice, with no difference in tumor growth. These data suggest that transplantation of IL-2 or IL-4 gene transfected cells could effectively induce immunity against LLC. IL-6 transfection did not induce immunity, but induced cachexia.

Animals↗
PubMed1991

Brain stem auditory-evoked potentials in meningomyelocele. Natural history of Chiari II malformations.

Brain stem auditory-evoked potentials (BAEPs) were recorded in 30 patients with meningomyelocele and shunted hydrocephalus ranging in age from birth to 33 years. Twenty-two of them had Chiari II malformation, one of which was symptomatic. In 22 cases, including 15 with Chiari II malformation, BAEPs were recorded repeatedly after periods ranging from 18 months to 7 years. The results were as follows: (1) III-V interpeak latency (IPL) decreased progressively from prolonged to the normal range with growth until 25 years of age; (2) I-III IPL tended to prolong gradually from the normal range; (3) these findings may indicate that the natural history of Chiari II malformation is delayed maturation of the brain stem and intensification in the elongation and stretching of the hindbrain and lower cranial nerves.

Adolescent↗
PubMed1991

Actinomycosis of the larynx.

Actinomycosis is a disease characterized by a chronic suppurative and granulomatous process which tends to form multiple pyogenic draining sinus tracts. The most common site in which it occurs is the cervico-facial region, especially in the submandibular area. The exudates from the fistulous tracts usually contain yellow granules known as "sulfur granules," which can be considered as a hallmark of actinomycosis. We report a rare case of laryngeal actinomycosis which occurred in a 68-year-old male who had been irradiated 8 years before due to laryngeal carcinoma. During the admission, the patient was also diagnosed as being a myelodisplastic syndrome carrier. The patient was treated successfully with penicillin 10 million IU administered daily over 40 days. The etiologic agents, predisposing factors, diagnostic procedures, and available treatments are discussed, and the pertinent literature is reviewed herein.

Actinomycosis↗
PubMed1991

Histochemical localization of calcium with potassium pyroantimonate in the articular tissues in calcium pyrophosphate dihydrate crystal deposition disease.

The ultrastructural localization of calcium in the articular cartilage, meniscus, and synovium of patients with calcium pyrophosphate dihydrate (CPPD) crystal deposition disease was examined by using potassium pyroantimonate. Focal areas with deposition of CPPD crystals in each tissue showed electron-dense precipitates of the antimony-calcium complex: (1) in the cytoplasm of hypertrophic chondrocytes around CPPD crystals, especially on the margins of intracellular lipid droplets or within electron-dense amorphous material or both; and (2) on the margins of lipid droplets and within electron-dense amorphous material in the degenerated matrix surrounding the hypertrophic chondrocytes. The slender rodlike structures consisting of electron-dense precipitates of the antimony-calcium complex, suggestive of the precursor to rodlike CPPD crystals, were also observed in the degenerated matrix. These findings suggest that the hypertrophic chondrocytes may contribute to the formation of CPPD crystals by intracellular accumulation of calcium and subsequent release of high concentration of calcium into their surrounding matrix.

Aged↗
PubMed1989

Vector analysis of three-dimensional evoked potentials: eccentric dipoles.

The quantitative description of three-dimensional cerebral evoked potentials is extended to include eccentric dipolar sources. Eccentricity-related distortions in dipole orientation and magnitude are assessed. The use of nonstandard montages, the prediction of topographic surface maps, dynamic analysis, and theoretical mechanisms of planar segment formation are discussed.

Brain↗
PubMed1989

[Comparisons of bioavailability of various calcium salts. Utilization incisor dentin in parathyroidectomized rats].

In the present study, we compared the bioavailability of various calcium salts in the diet such as calcium lactate, calcium carbonate and calcium phosphate by examining the effects of these calcium salts on serum calcium concentration and on the mineralization of incisor dentin in parathyroidectomized (PTXed) rats. Each rat was given daily 12 g of a low calcium (0.1% Ca) diet beginning from 3 days before the operation and continuing for 11 days after. Then the diet was changed to those containing various calcium salts (1.5% Ca). The serum calcium and phosphorous concentrations were examined every three days, just before feeding time and 6 hours after. The degree and site of the mineralization of incisor dentin were examined histologically by a time marking method using lead acetate. In the PTXed rats maintained on a low calcium diet, the serum calcium concentration decreased to about 4.5 mg/dl and the mineralization of incisor dentin was inhibited. On the 11th day, just before feeding on diets containing various calcium salts, the serum calcium concentrations were very similar for each group, but at 6 hours after feeding, concentration was 7.6 mg/dl in the calcium lactate group, 6.2 mg/dl in the calcium carbonate group and 4.8 mg/dl in the calcium phosphate group. On the 17th day following administration of the high calcium diets, the serum calcium concentrations were 9.8 mg/dl in the calcium lactate group, 8.4 mg/dl in the calcium carbonate group and 4.4 mg/dl in the calcium phosphate group. Mineralization of the incisor dentin was best in the calcium lactate group, moderate in the calcium carbonate group and poor in the calcium phosphate group. We also examined the effects of dietary phosphorus contents on serum calcium concentrations and on the mineralization of incisor dentin using PTXed rats. On the 17th day following the administration of diets (1.5% Ca, with calcium lactate) containing various amounts of phosphorus, the serum calcium concentrations in the calcium lactate group were 8.8 mg/dl (0.4% P), 6.9 mg/dl (0.8% P) and 4.2 mg/dl (1.6% P) respectively. Mineralization of incisor dentin was also inhibited in rats fed a high phosphorus diet. These results suggest that in PTXed rats, absorption of calcium from the intestines and mineralization of the incisor dentin is best by the administration of calcium lactate, moderate by calcium carbonate and poor by calcium phosphate, and that phosphorus in the diet inhibits calcium absorption from the intestines.

Animals↗
PubMed1989

A histological study of calcium pyrophosphate dihydrate crystal-deposition disease.

Synovial, meniscal, articular cartilage, and other connective tissue from fifty-seven patients who had calcium pyrophosphate dihydrate crystal-deposition disease was examined by light microscopy, electron microscopy, and electron-probe microanalysis. Safranin O-positive hypertrophic chondrocytes that contained proteoglycans were observed in the tissues of each patient. Microcrystals that were suggestive of early precipitation of crystals were found in the degenerating matrix surrounding hypertrophic chondrocytes. The matrix contained electron-dense amorphous material, including proteoglycans and debris of cellular components. The microcrystals were often seen in contact with degenerating collagen fibers. There was never any histological evidence of formation of crystal in the areas that had no hypertrophic chondrocytes. Chondrocytes of this kind, surrounded by characteristic degenerating matrix, were never observed in the articular tissue from sixty-one patients who had only osteoarthritis. On the basis of our results, we speculate that electron-dense amorphous material containing proteoglycans and debris of cellular components, and the degenerating collagen fibers that were seen around the hypertrophic chondrocytes, may play important roles in the formation of calcium pyrophosphate dihydrate crystals.

Adult↗
PubMed1989

Ultrastructural study of articular cartilage in experimental pyogenic arthritis.

Ultrastructural changes of the articular cartilage at the early stage of experimental pyogenic arthritis were studied by electron microscopy. The superficial zone of the cartilage at the site of the cartilage-synovium junction demonstrated far more changes than those at the site of the free surface of the articular cartilage. Changes were observed at the cartilage-synovium junction as early as four hours after the intraarticular injection of the infecting organism. The most interesting finding was migration of erythrocytes and polymorphonuclear leucocytes into the superficial zone of the cartilage at the early stage. The pericellular matrix in the middle zone became so loose in some areas that collagen fibrils were partially exposed after three days. The naked collagen fibrils were tapered, nicked and irregular in size after seven days.

Animals↗
PubMed1988

Histologic localization of lipid in the articular tissues in calcium pyrophosphate dihydrate crystal deposition disease.

We demonstrated the histologic localization of lipid in the articular cartilage, meniscus, and synovium in calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, by staining with Sudan III. Almost all the sites of tophus-like deposits of CPPD crystals and the degenerated matrix containing low concentrations of scattered CPPD crystals stained strongly with Sudan III. Transmission electron microscopy demonstrated round or oval lipid droplets in more than half of the chondrocytes around the crystals in each of these tissues. Small lipid droplets were also seen on or around the crystals. These findings suggest that lipids are abundant at the site of CPPD crystal deposition and may be involved in CPPD crystal formation.

Aged↗
PubMed1988

Persistent hemarthrosis of the shoulder joint with a rotator-cuff tear in the elderly.

Three elderly patients developed persistent hemarthrosis of the shoulder joint without having suffered injury. Complete tears of the rotator cuff, attrition of the undersurface of the acromion, and instability were noted in the affected shoulders. Synovial fluids examined from two patients contained many alizarin red S-positive microspheroids. The synovium obtained at surgery from two patients showed hypervascularity, vasodilatation, and severe degenerative changes of collagenous tissues. The tendon of the m. supraspinatus showed infiltrations of multinucleated giant cells around calcified deposits consisting of hydroxyapatite crystals. Anatomical and mechanical derangements, and possible biological reactions following phagocytosis of hydroxyapatite crystals, may have contributed to the persistent hemorrhage in the shoulder joints.

Acromion↗
PubMed1988

A modified extended middle cranial fossa approach for acoustic nerve tumors. Results of 125 operations.

During the past 10 years, 125 operations for acoustic nerve tumors were performed on 114 patients at the authors' institution using a modified extended middle cranial fossa approach. This approach is based on a combination of King and Morrison's translabyrinthine-transtentorial approach and on the extended approach through the middle cranial fossa described by Bochenek and Kukwa. There were two hospital deaths (operative mortality 1.6%). In 102 operations on the initial tumor, total removal was performed in 89 cases (87%), and in 71 (80%) of these the facial nerve was anatomically preserved. Intracranial end-to-end anastomosis was performed on five of the 18 sacrificed facial nerves; a facial-hypoglossal anastomosis was carried out in the remaining 13 patients and in five (7%) of the 71 patients whose anatomically preserved facial nerve functioned poorly. In seven (39%) of the 18 patients in whom an attempt to preserve hearing was made, postoperative hearing was saved. In 23 operations on 17 patients for recurrent tumors, most of which had previously been removed subtotally via the suboccipital approach, total removal was accomplished in 13 (57% of the 23 reoperations and 76% of the 17 patients). At reoperation, the facial nerve was preserved in six (55%) of the 11 patients in whom the facial nerve had not been sacrificed. Postoperative leakage of cerebrospinal fluid occurred in 11 cases (8.8%), with rhinorrhea in 10 cases and otorrhea in one. Five of the fistulas were corrected by surgery and the rest healed spontaneously. Other complications were not significant.

Adolescent↗
PubMed1988

[Intraoperative electrophysiological monitoring for hearing preservation in acoustic neurinoma surgery].

Five acoustic neurinomas have been operated with hearing preservation as a goal. We monitored intraoperative brainstem auditory evoked potentials (BAEP) in all five cases, electrocochleogram (ECoG) using needle electrode in external auditory meatus in four, and compound action potentials directly recorded from the cochlear nerve (CAP VIII) in three. In all five cases the tumor was totally resected and cochlear nerve was anatomically preserved. However, in only one case useful hearing was preserved with preservation of all wave forms of the BAEP. Another patient with preservation of all wave forms of BAEP and the ECoG showed postoperative severe hearing loss. Other three patients showed postoperative severe hearing loss: only Wave I of BAEP and ECoG were preserved without preservation of the CAP VIII in one whose cochlear nerve was thought to be damaged in cerebellopontine angle cistern; Wave I of BAEP, ECoG and CAP VIII were preserved in one in whom it was suggested cochlear nerve near brainstem or cochlear nucleus was damaged; none of the BAEP, ECoG and CAP VIII was preserved in one in whom it was suggested distal cochlear nerve, or internal auditory artery was damaged. These different patterns of changes suggested that different causes for the hearing loss and difficulties in hearing preservation during acoustic neurinoma surgery. Having identified the putative mechanism of the hearing loss by monitoring those potentials, suggestions are made about how such hearing loss might be avoided. For preservation of the hearing in acoustic neurinoma surgery, all of those potentials including all wave forms of BAEP, ECoG and CAP VIII should be preserved during surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1988

[Clinicophysiological study of multimodality evoked potentials and computed tomographic findings in persistent vegetative state].

The auditory brainstem response (ABR), short latency somatosensory evoked potential (SSEP) and visual evoked potential (VEP) of patients in the persistent vegetative state (PVS) are reported, and the correlations between the electrophysiological findings and the CT scan findings with the three clinical grades of the PVS (transitional, incomplete and complete vegetative syndromes) are discussed. Twenty two patients in a vegetative state caused by subarachnoid hemorrhage (3), hypertensive intracerebral hemorrhage (5), cerebral infarction (6), head injury (3), cerebral anoxia (4) and brain tumor (1). Each evoked response was evaluated for the presence or absence of abnormalities and assigned a grade ranked I to III. Briefly an evoked response was assigned a grade I, II, III if it satisfied the respective criteria of normal, moderately abnormal and severely abnormal or absent electrical activity. On the other hand CT scan findings in the PVS were evaluated for abnormal low density areas, ventricular dilatation and enlargement of the sulci and cisterns indicative of atrophy of the brain parenchyma. SSEP and VEP were better correlated with the clinical grade than ABR, and upper brainstem atrophy and abnormal low density area in CT scan findings were more valuable as an index to expresses the clinical features than ventricular dilatation. On the basis of these results, it is concluded that studies of ABR, SSEP and VEP associated with CT scan findings in the PVS could be a useful diagnostic aid to evaluate the lesions of these patients.

Adult↗
PubMed1987

Hydroxyapatite deposition in osteoarthritic articular cartilage of the proximal femoral head.

Hydroxyapatite crystal deposition in the articular cartilage of the proximal femoral head was examined by using light and electron microscopy and electron probe microanalysis. The hydroxyapatite deposition was significantly more frequent in patients with osteoarthritis (40.7%, 22 of 54) than in control subjects (6.0%, 3 of 50) (P less than 0.001). Initial deposition of needle-like crystals was always seen on or within the electron-dense, amorphous material around the degenerating hypertrophic chondrocytes. Matrix vesicles were rarely seen in the calcifying areas.

Cartilage, Articular↗