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Biomedical subjects

T Yoshihara

Publications and source records attributed to T Yoshihara.

At least 163 records · Page 9Linked to original sources
PubMed1988

Immunocytochemical study of catecholaminergic innervation in the guinea pig cochlea.

The enzymes for synthesis of catecholamine, tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), and phenylethanolamine N-methyl transferase (PNMT), have been immunocytochemically localized in the guinea pig cochlea. Two groups of catecholamine-containing neurons could be distinguished. The first group, which was TH-positive/DBH, PNMT-negative, was found in the inner spiral bundle and the tunnel spiral bundle. The other group was TH, DBH-positive/PNMT-negative, and was found around the blood vessels. The immunocytochemical evidence obtained in this experiment suggests that the catecholamines should play a functional role in the guinea pig cochlea.

Animals↗
PubMed1988

Temporal bone findings in a newborn infant with multiple congenital anomalies.

Temporal findings were described in the case of a newborn infant with severe congenital anomalies. The autopsy demonstrated severe multiple bone abnormalities in the face and extremities, but no organ abnormalities. Middle and inner ear anomalies were characterized by columella-shaped stapes on both sides, deformed cochlea and absence of spiral ganglion cells on the left side, enlarged saccule and common crus, abnormal branch of superior vestibular nerve on the left side, and wide endolymphatic duct and sac on the right side.

Ear, Inner↗
PubMed1987

Light and electron microscopic studies of localized laryngeal amyloidosis.

We performed light and electron microscopic studies in a case of localized supraglottic laryngeal amyloidosis involving a 55-year-old woman. Tissue specimens were stained with hematoxylin and eosin, and alkaline Congo red with or without permanganate (KMnO4) treatment, and were also examined with peroxidase-antiperoxidase immunohistochemistry. Biopsy specimens from the epiglottis showed diffuse replacement of the subepithelial region by amyloid, which showed a typical green birefringence under polarized light. Tissue affinity for Congo red was persistent after the KMnO4 treatment. However, the tissue sections showed a positive reaction only to the anti-P component antibody. Electron microscopic studies revealed some disorders of the plasma cells, suggesting that these cells play an important role in focal production of amyloid fibrils.

Amyloid↗
PubMed1987

Cytochemical localization of Ca++-ATPase activity in the lateral cochlear wall of the guinea pig.

Ca++-ATPase activity was examined cytochemically in the lateral cochlear wall of the guinea pig. The reaction products showing Ca++-ATPase activity were found along the folded plasma membrane of the strial marginal cells. In contrast, little or no reaction was seen on the apical surfaces of these cells. There were also marked reaction products on the microvilli and the endolymphatic cell surface of Reissner's membrane, and the apical and lateral plasma membranes of the spiral prominence and the external sulcus cells. These reactions completely disappeared when Ca++ or ATP was removed from the incubation medium. Our results strongly suggest that Ca++-ATPase plays an important role in Ca++ transport system for the regulation of Ca++ concentration in the cochlear endolymph.

Animals↗
PubMed1987

Localization of Na+, K+-ATPase activity in the tegmentum vasculosum of the chick cochlea.

We studied the localization of Na+, K+-ATPase activity in the chick cochlea, utilizing a cytochemical method of K+-p-nitrophenylphosphatase (K+-NPPase), and found that the enzyme activity was limited to the dark cells of the tegmentum vasculosum (TV). Our present results indicate that the dark cells of the TV play an essential role in the maintenance of the ionic composition of the cochlear endolymph.

Animals↗
PubMed1987

Cytochemical studies of Ca++-ATPase activity in the vestibular epithelia of the guinea pig.

We used ultracytochemistry to examine Ca++-ATPase activity in the vestibular epithelia of the guinea pig. Many reaction products were found along the basolateral plasma membrane of the vestibular dark cell. There were also marked reaction deposits on the apical and lateral cell membranes of the transitional cells, and the utricular and saccular wall cells. Both sensory and supporting cells showed Ca++-ATPase activity along their ciliary membrane and apical-lateral cell surfaces. Our findings indicate that the Ca++-ATPase activity found on the plasma membrane is closely related to Ca++-transport across the plasma membrane. When either Ca++ or ATP was omitted from the incubation medium, enzyme activity (as seen by the staining reaction present) was completely abolished. Our present results suggest that Ca++-ATPase located in the vestibular epithelia plays a significant role in the regulation of the Ca++-concentration in the vestibular endolymph.

Animals↗
PubMed1987

Ultrastructural changes of statoconia after segmentation of the otolithic membrane.

The chick vestibule transformed from a homogeneous epithelial layer at day 2 (stage 15) into a pseudo-stratified epithelial layer at day 4 (stage 24). The apical columnal appearance of sensory cells was evident by day 6 (stage 29). In the supporting cells of the saccule and utricle large rough endoplasmic reticulum cisterns filled with material similar to the primitive organic matrix. Fibrillar material of the otolithic membrane remained attached to the supporting cells and accumulated over the saccule and utricle. The primitive otolithic membrane acquired stress-like lines and statoconial units emerged from the upper surface without a central core. Statoconia thickened at the periphery and a central core formed. Calcium was deposited between the fibrils of older statoconia which were located on top of the segmenting membrane. DIAMOX inhibited statoconia formation and/or prevented calcium and the matrix from associating. Large statoconia (100-200 microns diameter) were formed in embryos injected with this carbonic anhydrase inhibitor. Gel electrophoresis of immature statoconial complexes yielded at least 5 major protein bands between 25 and 210 kDa. Ouabain-sensitive potassium-dependent p-nitrophenylphosphatase activity was demonstrated in the endolymphatic sac of newly hatched chicks.

Acetazolamide↗
PubMed1987

Cardiopathology of sudden cardiac death in the race horse.

Twenty thoroughbred race horses were selected for postmortem cardiopathological study of sudden cardiac death; ten of the twenty horses died suddenly. In order to define accurately the morphological changes observed in these ten hearts, ten other thoroughbred race horses considered to have normal hearts were selected as a control group and studied by postmortem coronary angiography. Of the ten horses that died suddenly, eight were witnessed to have died either during or shortly after training or racing. The death was instantaneous except in one horse, which showed ventricular tachycardia and died 4.5 h after a race. The other two died unexpectedly in the stable at night. Pathologically, the horses that died suddenly generally showed multifocal myocardial lesions that were ischemic and fibrotic. These lesions were found in the atrial tissue close to the sinoatrial (SA) node and in the atrioventricular (AV) junction, including the upper portion of the interventricular septum. Such myocardial lesions were often associated with vascular changes including arterio- and/or arteriolosclerosis. Angiographically, the SA node appeared to be perfused by atrial branches of the left and right coronary arteries. One branch originating from the left coronary artery gave off a few branches into the AV junction. These pathological findings, mainly consisting of both atrial lesions and lesions in the AV junction, were similar to those observed in horses with either atrial fibrillation, SA block, or paroxysmal ventricular tachycardia. A finding of particular interest was the angiographic demonstration that the blood supply to the AV junction partly came from the SA node artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Experimental studies on thermotolerance in hyperthermia treatment of cancer].

Thermotolerance was investigated in hyperthermia using FM3A cells in vitro and in vivo. FM3A cells were heated at 42.0 degrees C, 43.0 degrees C and 44.0 degrees C and the survival rate of the cells was decreased in this order. In in vitro experiments, thermotolerance induced by heating at 43.0 degrees C for 30 min reached at maximum, when the heating interval was 12 hr and thermotolerance induced by heating at 44.0 degrees C for 30 min reached at maximum, when the heating interval was 12 to 24 hr. In in vivo experiments, thermotolerance induced by heating at 42.0 degrees C, 43.0 degrees C and 44.0 degrees C continued for 48 hr after initial heating and disappeared after 96 hr. In the repeated hyperthermia experiments, 7 times with 24 hr interval heating or 4 times with 48 hr interval heating did not show the significant inhibition of tumor growth as compared with the control group at 42.0 degrees C, 43.0 degrees C and 44.0 degrees C. However, twice with 96 hr interval heating indicated the significant inhibition of tumor growth at 42.0 degrees C, 43.0 degrees C and 44.0 degrees C. From these results it is suggested that hyperthermia treatment should be repeated after the disappearance of thermotolerance.

Animals↗
PubMed1986

Clinical studies on the transabdominal resection of esophagocardial cancer and cervical anastomosis using bypass methods. Analysis of data on 76 patients.

Transabdominal resection for esophagocardial cancer and reestablishment of alimentary continuity using bypass methods were performed in 76 patients. Thirteen underwent a bypass with a gastric tube and in 30, a colonic segment was prepared. In the remaining 33, a jejunal segment was used as a bypass organ, with considerable success. The 5 year survival rates were 68.8 per cent in those with stages (I + II), 16.5 per cent in those with stage III, 12.6 per cent in those with stage IV and 22.5 per cent in all cases, indicating similar results compared to those with cancer located in the upper third of the stomach with the limited proximal extension within the esophagocardial junction and operated on during the same period.

Adenocarcinoma↗
PubMed1986

Blunt esophageal resection for esophagocardial cancer: blunt dissection and retrosternal esophagojejunostomy using the EEA stapler.

A transabdominal resection for esophagocardial cancer and cervical esophagojejunal anastomosis was devised by our group. Since 1973, seventy-six such operations have been done and the long-term follow up study showed a good survival rate. These findings justify our efforts to perform the operative procedure without opening the chest. To obviate cervical esophagocutaneostomy which is indispensable to this method and may contribute to complications, we altered the operative procedure to blunt dissection of the esophagus and retrosternal esophagojejunostomy, using the EEA stapler. Details of the operative procedures used for nine patients are reported herein.

Aged↗
PubMed1986

Poorly differentiated fibrosarcoma (spindle cell sarcoma) involving the temporal bone.

A case of metastatic fibrosarcoma of the temporal bone was studied histopathologically. The primary site of this tumor was the posterior neck region. The initial major symptom of the patient was a left facial nerve paralysis. Although the patient underwent a suboccipital posterior craniectomy, radio-, and chemotherapy, she eventually died from multiple metastases. Histological examination of the temporal bones showed an extensive tumor invasion in the external auditory canal, middle ear cavity, middle ear muscle, tympanic membrane, mastoid cavity, petrous apex, facial nerve, and superior division (distal segment) of the vestibular nerve (left ear). The route from the stylomastoid foramen to the superior division of the vestibular nerve via the facial nerve canal could be one of the possible passages of tumor invasion.

Adult↗