Biomedical subjects

I Ohtani

Publications and source records attributed to I Ohtani.

At least 37 records · Page 2Linked to original sources

PubMed1993

[The localization and the function of carbonic anhydrase in the inner ear].

Carbonic anhydrase (CA) is distributed in a wide variety of animal cells and tissues, especially in cells and tissues involved in rapid exchange or transport of protons, bicarbonate, or other ions. Although localization of this enzyme and its physiological roles in the inner ear have been investigated extensively, full clarification has yet to be achieved. We have conducted a histochemical investigation of CA localization in the inner ear of the guinea pig by Hansson's method, with emphasis on improved fixation. The histochemical reaction for CA activity is localized in the outer and inner hair cells of the organ of Corti, Deiters' cells or nerve endings, inner pillar cells, Boettcher's cells, stria vascularis, spiral ligament, vasculo-epithelial zone and spiral ganglion cells. The physiological roles of CA in the inner ear, particularly in relation to the production or absorption of endolymph, are discussed in this report.

Animals↗

PubMed1992

In vitro effects of glycosylated insulin in perfused liver and hindquarter in rats.

Using the perfused liver and hindquarter of the rat, the uptake of glycosylated insulin and its effect on glucose output were investigated. Insulin was glycosylated in ambient high glucose concentration, and glycosylated insulin GI80 (insulin incubated with 0.08% glucose), GI350 (incubated with 0.35% glucose), and GI1000 (incubated with 1% glucose) were prepared. The liver and hindquarter were perfused with nonglycosylated insulin (N-GI) or glycosylated insulin at a concentration of 100 or 1000 microU/ml. There were no significant differences in the fractional uptake of insulin by perfused liver and hindquarter despite glycosylation. Insulin-induced decrement in glucose output was significantly lower in the liver perfused with GI1000 than that in the liver perfused with N-GI, GI80, and GI350 at an insulin concentration of 100 microU/ml. There were no significant differences in insulin-induced decrement in glucose output between the hindquarter perfused with N-GI, GI80, GI350, and GI1000. These results suggest that when insulin (100 microU/ml) is incubated with a markedly elevated concentration of glucose (1000 mg/dl) its biological activity is reduced in the liver, but not in the hindquarter.

Animals↗

PubMed1992

The hearing loss in Wegener's granulomatosis: relationship between hearing loss and serum ANCA.

We observed the change of hearing for 1 year in a patient with Wegener's granulomatosis. We also studied anti-human neutrophil cytoplasm antibody (ANCA), which is believed to be specific for this disease and to be associated with disease activity. From these progresses, changes in hearing were considered to be generally related with the general condition and with the ANCA titer level. Because hearing loss in our case was improved by steroids and immunosuppressants, and because ANCA is the autoantibody observed in angiitis syndrome, hearing loss in this case of Wegener's granulomatosis was suspected of being caused by angiitis of the middle and inner ear induced by autoimmune reaction.

Adult↗

PubMed1992

Four cases of metastatic lymphoma into the temporal bone.

A histopathological study on 17 temporal bones obtained from 9 patients who died of malignant lymphoma revealed metastasis of malignant lymphoma in 7 temporal bones from 4 of them. There were no differences in stages at the initial diagnosis between the cases with metastasis and those without metastasis. However, the higher was the frequency of metastasis, the longer became the period from the first medical examination to death. In addition, malignant lymphoma was considered to metastasize into the temporal bone by the following two routes, 1) direct infiltration or invasion from the cerebrospinal fluid and 2) hematogenous metastasis or invasion.

Adult↗

PubMed1992

Immunohistochemical evaluation with Ki-67: an application to salivary gland tumours.

Using Ki-67, a monoclonal antibody, the proliferating capacity of 15 salivary gland tumours, including nine pleomorphic adenomas, four adenoid cystic carcinomas, one mucoepidermoid carcinoma and one acinic cell carcinoma was determined immunohistochemically, using normal salivary gland tissue as a control. The frequency of Ki-67 positive cells was 4.7 percent in the normal salivary gland and one percent in pleomorphic adenomas, whereas the average frequency in malignant tumours was 18.3 percent. Among adenoid cystic carcinomas, the frequency was related to the morphological type; the solid sub-type had the highest frequency of Ki-67-positive cells. As this sub-type is recognized as the most aggressive of these tumours, this technique has the potential of providing an early indication of the clinical behaviour of a tumour.

Carcinoma, Adenoid Cystic↗

PubMed1992

Adrenergic mechanism in hyperketonemia in thyrotoxic and starved rats.

To evaluate the possible role of the adrenergic mechanism in hyperketonemia in hyperthyroidism and starvation, the plasma concentrations of FFA, acetoacetate (AcAc), and beta-hydroxybutyrate (BOHB) were measured in thyrotoxic and starved rats for 96 hours. Thyrotoxemia was induced in rats by a daily subcutaneous thyroxine (100 micrograms/kg/day) injection carried out for 7 days. Some of the thyrotoxic and starved rats were administered subcutaneous phentolamine (2 mg/kg, twice daily) or propranolol (0.1 mg/kg, twice daily). Plasma levels of FFA, AcAc, and BOHB were significantly increased in thyrotoxic and starved rats compared with the control rats. Phentolamine and propranolol administration did not alter plasma levels of FFA, AcAc, and BOHB in thyrotoxic rats. In starved rats, propranolol did not alter plasma levels of FFA, AcAc, and BOHB, however, phentolamine did increase plasma levels of FFA, AcAc, and BOHB. These results indicate that the adrenergic mechanism may not contribute to the hyperketonemia in thyrotoxic rats, but may have a slight inhibitory effect on ketogenesis in starvation probably due to alpha-antilipolytic action.

3-Hydroxybutyric Acid↗

PubMed1992

In vitro effects of glycosylated insulin and glucagon in perfused liver of the rat.

Using perfused liver of the rat, the hepatic uptake of glycosylated insulin (GI) and glucagon (GG) and its effects on hepatic glucose output were investigated. Insulin and glucagon were glycosylated in ambient high glucose concentration, and GI80 or GG80 (insulin or glucagon incubated with 0.08% glucose), GI350 or GG350 (incubated with 0.35% glucose), and GI1000 or GG1000 (incubated with 1% glucose) were prepared. The liver was perfused with the medium containing 1000 microU/ml insulin and 200 pg/ml glucagon or 200 microU/ml insulin and 1000 pg/ml glucagon. The fractional uptake of insulin or glucagon by perfused liver was not significantly altered by the glycosylation. In the liver perfused with 1000 microU/ml insulin and 200 pg/ml glucagon, glucose output was not changed by the glycosylation of the hormones, while in the liver perfused with 200 microU/ml insulin and 1000 pg/ml glucagon, GI1000 reduced its biological activity, as reflected by insulin-mediated decrease in glucose output. These results suggest that in the liver insulin incubated with markedly high concentration of glucose reduces its biological activity at a physiological concentration in the presence of high concentration of glucagon.

Animals↗

PubMed1992

Oral health conditions and denture treatment needs in institutionalized elderly people in Japan.

Oral health conditions, including dental conditions, temporomandibular joint (TMJ) conditions, denture status, and oral hygiene status, were assessed on 1908 institutionalized elderly people 65 yr of age and older at 29 of the 30 existing institutions in the city of Kitakyushu, Japan. The percentage of edentulous people was 27% in the 65-74-yr-old group, and increased with age to 56% in the 85 yr and older group. In dentate persons, the mean number of remaining teeth and DF teeth were 13.4 and 8.6, 9.5 and 6.8, and 8.4 and 6.5 in the groups aged 65-74 yr old, 75-84 yr old, and 85 yr and older, respectively. 81% of all the persons examined had no unusual symptoms in their TMJ. A clicking sound was the most frequent symptom (17%). Hygiene of both their teeth and dentures was very poor. Of all the subjects, 36% needed new full and/or partial denture(s), and 41% needed only repair. When the institutionalized elderly people were compared according to their general health condition, no clear differences were observed in percentage of edentulousness, mean number of remaining teeth and DF teeth, and TMJ conditions. However, a higher level of both untreated teeth and denture treatment needs, and poorer oral hygiene, was found in elderly people having poor general health than was observed in those with better health.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

Bronchoscopy for airway foreign bodies: consideration based on an extraordinarily large one.

An extraordinarily large foreign body was lodged in the trachea of a 14-year-old boy. It was a rectangular piece of lead measuring 35 x 12 x 5 mm and was removed by a lower rigid bronchoscope introduced through a tracheostoma. Based on experiences of this and 6 other cases of tracheobronchial foreign body treated by this method, we discuss what approach should be used to extract tracheobronchial foreign bodies. We believe that lower bronchoscopy is still useful in removing foreign bodies very large or located in the peripheral bronchus, although it is used much less often today than before.

Adolescent↗

PubMed1991

Possible role of adrenergic mechanism in starvation-induced reduction in circulating thyroxine and triiodothyronine in rats.

To elucidate the possible role of adrenergic mechanism in thyroid hormone metabolism during starvation, serum thyrotropin (TSH), thyroxine (T4), and 3,5,3'-triiodothyronine (T3) levels and conversion of T4 to T3 in perfused liver were investigated in fasting (60 h) and fed rats. Propranolol (0.5 mg/kg), yohimbine (0.3 mg/kg) or phentolamine (5.0 mg/kg) was subcutaneously injected to the rat every 12 h. Serum levels of TSH, T4, and T3 were significantly lower in fasting rats than in fed rats. Although propranolol, yohimbine, and phentolamine administration did not significantly alter circulating TSH, T4 and T3 levels in fed rats, phentolamine partly inhibited the starvation-induced reduction in circulating TSH, T4, and T3. Thyroxine uptake and T3 production in perfused liver were significantly lower in fasting rats than in fed rats. Phentolamine treatment did not alter the T4 uptake and T3 production in perfused liver of fasting rats. These results suggest that alpha-adrenergic mechanism may have some role in starvation-induced reduction in circulating T4 and T3, and that phentolamine partly inhibited this phenomenon probably through the inhibitory effect on reduction in circulating TSH during starvation.

Animals↗

PubMed1991

Uptake of beta-hydroxybutyrate in perfused hindquarter of starved and diabetic rats.

To elucidate the peripheral ketone body uptake and the role of insulin in regulating peripheral ketone body utilization in starvation and diabetes mellitus, uptake of beta-hydroxybutyrate (BOHB) was investigated in the perfused hindquarter of starved (72 hour) or streptozotocin-induced (65 mg/kg, intraperitoneally) diabetic rats. Blood concentration of BOHB was significantly higher in diabetic (1,380 +/- 250 mumol/L) and starved (1,229 +/- 245 mumol/L) rats than in controls (104 +/- 8 mumol/L). The hindquarter was perfused with synthetic medium at a flow rate of 0.5 mL/g muscle weight/min. BOHB was added to the medium at a concentration of 0.1, 0.5, 2, or 10 mmol/L, and insulin was added at a concentration of 20, 100, or 500 microU/mL. In the hindquarter perfused with 0.1, 0.5, 2, or 10 mmol/L BOHB, fractional uptake of BOHB in the absence or presence of insulin was significantly lower in diabetic and starved rats than in controls. The addition of 100 or 500 microU/mL insulin significantly increased BOHB uptake in the perfused hindquarter of control rats; however, insulin addition did not significantly increase BOHB uptake in the perfused hindquarter of starved and diabetic rats. These results suggest that BOHB uptake is markedly reduced in the perfused hindquarter of starved and diabetic rats, and that physiological dose of insulin stimulates BOHB uptake in control rats, but not in starved and diabetic rats.

3-Hydroxybutyric Acid↗

PubMed1991

Serum lipid and apolipoprotein levels in non-hypertensive lean NIDDM patients.

To determine the possible role of a glycaemic control in lipid metabolism in non-insulin-dependent diabetes mellitus (NIDDM) patients, serum lipid and apolipoprotein levels were measured in well-controlled and poorly controlled lean NIDDM without proteinuria and hypertension. A sample of 96 lean NIDDM patients (body mass index less than 25 kg m-2 in men and less than 27 kg m-2 in women) were divided into two groups: group I, where the HbA1c concentration had been less than 6% for the previous 3 months, and group II, where the HbA1c concentration had been greater than 8% for the previous 3 months. Serum total cholesterol, triglyceride, and HDL-cholesterol levels showed no significant differences between groups I and II. Furthermore, serum levels of apolipoproteins AI, AII, B, CII, CIII, and E did not differ significantly between groups I and II. These results suggest that glycaemic control did not influence lipid metabolism in lean NIDDM patients.

Adult↗

PubMed1991

CPITN assessments in institutionalised elderly people in Kitakyushu, Japan.

A CPITN survey was conducted on 1958 institutionalised elderly people aged 59 years and older at 29 of the 30 public and private institutions in the city of Kitakyushu, Japan. About 60 per cent of the sample was edentulous, and the prevalence of periodontal conditions was high. The percentages of dentate subjects with healthy gingivae, bleeding on probing, calculus, shallow pockets, and deep pockets were 3, 4, 32, 52, and 9 per cent respectively. Half the sextants in the dentate subjects were scored as excluded (less than two teeth), indicating that many teeth were missing. Only very few sextants were healthy. These findings indicate the importance of preventive programmes for periodontal diseases in the younger generations, because (a) dental care for the elderly population becomes more difficult with increasing age and (b) periodontal care, if it is available at all, is provided too late for most people.

Aged↗

PubMed1990

Temporal bone pathology in intracochlear schwannoma with profound hearing loss.

Intracochlear schwannoma was found in the temporal bone of a 85-year-old man in whom audiometric study, 26 days before death, had shown total deafness in the left ear. The tumor occupied the entire lumen of the cochlea in the basal turn involved Rosenthal's canal, but it occupied only the scala tympani in the second turn. Intralabyrinthine schwannomas are difficult to diagnose by clinical examination. They were discovered accidentally during destructive labyrinthectomy for presumed Ménière's disease or discovered incidentally by postmortem temporal bone pathology. Although intralabyrinthine schwannomas are a rare occurrence and cannot usually be diagnosed without surgery or postmortem histopathology, it is important to suspect the possibility of their existence in differential diagnosis of atypical Ménière's disease or unilateral idiopathic progressive deafness. Long-term follow-up is obviously necessary to exclude the tumor.

Aged↗

PubMed1990

Inner ear impairment following combined CDDP (platinum preparation) and radiation therapy.

Hearing ability was examined in patients with head and neck cancer treated by combined CDDP and electron beam therapy. In 3 of 7 patients with maxillary cancer, hearing impairment apparently attributable to the therapy was noted on the affected side. In one of these 3 patients, the temporal bone was observed, but the cause of hearing impairment could not be determined. We present patients with cancer of the external ear in whom radiation-caused hearing impairment worsened probably due to combined CDDP and electron beam therapy.

Adult↗

PubMed1990

Temporal bone findings in two cases of head injury.

Temporal bone findings in two cases of head injury are reported. In one patient, longitudinal fractures occurred in both temporal bones, and extended to the middle ear bilaterally. Bleeding was seen in the tympanic cavity, mastoid air cells, internal auditory meatus and facial nerve canal. Bleeding was observed in the scala tympani, cochlear aqueduct and endolymphatic sac, but there were no fractures. In the other patient, bleeding was seen in the internal auditory meatus and facial nerve canal. In the right ear, endolymphatic hydrops was observed in all turns of the cochlea.

Adult↗

PubMed1990

Immuno-electron microscopic study of keratin distribution in the cochlea using monoclonal antibody.

Keratin distribution in the cochlea has been studied immuno-electron microscopically by both pre-embedding and postembedding methods. Keratin immunoreactivity in the guinea pig cochlea was clearly demonstrated in Hensen's cells, the reticular lamina surrounding both outer and inner hair cells, outer and inner pillar cells, Claudius' cells, inner and external sulcus cells, interdental cells of the spiral limbus, Reissner's membrane, border cells, inner phalangeal cells, Deiters' cells, and spiral prominence cells. Keratin expression at the ultrastructural level showed a nonfilamentous keratin system in the cytoplasm of cochlear supporting cells.

Animals↗

PubMed1990

Learning efficiency of a toothbrush for mastering scrubbing method.

Toothbrushing with long horizontal strokes often causes traumatization of sound enamel and gingival tissues. Also, dental plaque on cervical and adjacent surfaces of teeth can hardly be removed because toothbrush tips cannot reach these regions adequately. A toothbrushing device which indicates overstroke was tested to determine the efficacy with which it makes subjects master brushing with short horizontal strokes following an initial period of instruction. The degree of learning measured in the testing group was superior to that of the control group immediately after the first instruction. Moreover after one week and 12 weeks, its efficacy persisted. The plaque elimination ratio, however, showed no significant difference between the testing group and the control.

Adult↗