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Biomedical subjects

K Kaga

Publications and source records attributed to K Kaga.

209 records · Page 12Linked to original sources
PubMedDate not supplied

Pure-tone audiometry and auditory brainstem responses in noise-induced deafness.

PURPOSE: The objective of this study is to find the relationship between pure-tone audiometry results and the auditory brainstem response wave abnormalities. SUBJECTS AND METHODS: The pure-tone audiometry (PTA) and auditory brainstem responses (ABRs) from 22 patients (44 ears) with diagnosed noise-induced permanent hearing loss were studied. Three indices of PTA were average thresholds of 0.5 kHz/, /1 kHz, and 2 kHz (PTA1); 2 kHz and 4 kHz (PTA2); and 4 kHz (PTA3) were subdivided into 3 thresholds of hearing. Their relationships with ABR results were analysed. The patterns of PTA from various groups of ABR wave patterns were studied. RESULTS: In this study, the abnormal ABR wave patterns were detected in 72.7% of the ears. The ears with prolonged ABR wave latency, absent early waves, prolong interpeak wave I-V latency was 20.5%, 18.2%, and 21.1%, respectively. Normal ABRs were recorded in 27.3% of the ears despite marked thresholds elevation of the PTA at high frequencies. Other relationships between PTA results and ABR wave results were discussed. CONCLUSION: There were relationships between severity of noise-induced hearing loss indicated by PTA and the patterns of ABR wave abnormalities among workers with noise-induced permanent hearing loss.

Aged↗
PubMedDate not supplied

The effect of methotrexate (MTX) on expression of signalling lymphocytic activation molecule (SLAM) in patients with rheumatoid arthritis (RA) and its role in the regulation of cytokine production.

OBJECTIVE: To investigate the effect of methotrexate (MTX) on cytokine production by activated CD4+ T-cells in patients with rheumatoid arthritis (RA). METHODS: The effect of MTX on intracellular expression of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), and cell surface expression of signalling lymphocytic activation molecule (SLAM) from freshly isolated peripheral blood mononuclear cells (PBMCs), and after in vitro culture with or without MTX, was analysed with flow cytometry in 18 patients with RA and 20 healthy controls. RESULTS: Intracellular expression of IFN-gamma and IL-4 on freshly isolated CD4+ T-cells was significantly higher in patients with RA than in the controls (p<0.05). Intracellular expression of both IFN-gamma and IL-4 after culture with MTX was significantly lower than those after culture without MTX in patients with RA. Although no significant difference was observed in SLAM expression on freshly isolated CD4+ T-cells between patients with RA and the controls, MTX significantly decreased SLAM expression on both activated IFN-gamma+ and IL-4+CD4+ T-cells in patients with RA. CONCLUSION: In vitro modulation of the cytokine network by MTX, IFN-gamma, and IL-4 is one of the major targets for MTX, and production of IFN-gamma and IL-4 by PBMCs may be suppressed by SLAM on activated CD4+ T-cell in patients with RA.

Aged↗
PubMedDate not supplied

Auditory brainstem response and neuropathology in a case of systemic T-cell lymphoma with intracranial metastasis.

A 58-year-old male with systemic T-cell lymphoma involving the brainstem eccentrically, showed varying abnormal auditory brainstem responses (ABRs). The initial ABR demonstrated a prolonged V wave peak latency and an I-V IPL on admission. Four months later, all waves were absent bilaterally. Neuropathological examination at autopsy revealed that most of the nuclei and tracts associated with the auditory system were destroyed by lymphoid cell infiltration. It suggested that in the early stages of this disease, lymphoid cells could have involved the lower brainstem and, subsequently, in the advanced stages invaded the inferior colliculus.

Brain Neoplasms↗
PubMedDate not supplied

Innominate artery erosion complicating use of tracheal tube with adjustable flange.

A tracheal tube having an adjustable flange (AF tube) can be adjusted in cases of abnormal depth from skin to trachea. In a 43-year-old man with squamous cell carcinoma of the floor of the mouth, an AF tube was inserted because of severe edema of pretracheal tissues. He developed innominate artery erosion on the 6th postoperative day caused by the malfitted AF tube and died of recurrent hemorrhage 5 days after a surgical repair of the wound. The AF tube should be utilized not routinely but only in individuals with abnormal anatomy of the neck or trachea. Use of the AF tube requires extra care in addition to routine care required in the case of a conventional tracheal tube. Its correct fit should be verified initially by radiography. Fiberoptic examination should be employed within days after tracheostomy for patients with an AF tube to determine whether the tracheal mucosa is intact.

Adult↗
PubMedDate not supplied

Vestibular findings and brainstem pathology in two siblings with Cockayne's syndrome.

Two siblings with Cockayne's syndrome (CS) are described. Both showed cachectic dwarfism, photosensitivity and progressive neurological dysfunction. The damped-rotation test revealed no vestibular nystagmus in one of them, and reduced per-rotatory nystagmus in the other. Neuropathological examination in the former subject disclosed neuronal loss with fibrillary gliosis in the vestibular nuclei, whereas neuronal degeneration was not apparent in the abducens nuclei, the oculomotor nuclei and the paramedian pontine reticular formation. Our findings suggest that CS might cause vestibular dysfunction as well as hearing loss and that the lesions in the vestibular nuclei might be related to the vestibular dysfunction.

Adolescent↗
PubMedDate not supplied

Autonomic nervous system of the cat middle ear mucosa.

The autonomic nerves of the cat middle ear mucosa were studied by the methods of surface preparation, histochemistry and electron microscopy. The tympanic nerve was found to contain large myelinated fibers probably of a sensory nature. Other sympathetic bundles consisted primarily of unmyelinated fibers with a sparse distribution of myelinated fibers. The inferior tympanic artery was accompanied by many vasomotor nerves and its branches were also innervated predominantly by adrenergic fibers. A dense neural network which showed acetylcholinesterase activity was found in the mucosa around the Eustachian tube orifice. These nerves consisted of several unmyelinated fibers encapsulated by a single Schwann cell just below the epithelium. The fine structure of the small ganglions of the tympanic plexus revealed that the cholinergic nerve endings synapse with the cell body of the ganglion. This finding suggests that these ganglions are autonomic.

Acetylcholinesterase↗
PubMedDate not supplied

Absence of later auditory brain stem response components, congenital horizontal nystagmus, and hypotonia in male infants.

Five male infants, all of whom showed findings of wave I or waves I and II only of the auditory brain stem response (ABR), congenital horizontal pendular nystagmus, and hypotonia of head and limbs in the early infantile period with later paresis, are discussed. Their ages ranged from 3 to 13 months at the first examination, at which time neither head control, sitting, nor walking had been attained. Follow-up studies of ABRs revealed persistent abnormalities with neither remission nor progression. In spite of these abnormalities, these infants responded well to voices and other sounds. The congenital nystagmus in each case was demonstrated by electronystagmography to have a frequency of 2 to 3 Hz. The correlation between clinical signs and ABR is uncertain as yet. However, our findings are strongly indicative of nonprogressive inborn abnormalities in the lower brain stem.

Brain Stem↗
PubMedDate not supplied

Comparison of roxatidine and famotidine on nocturnal gastric juice secretion.

Adult patients with symptoms of gastric disease were randomly assigned to two treatment groups (roxatidine group, n = 115; famotidine group, n = 113) or untreated control group (placebo, n = 111). The treatment groups randomly received 75 mg of roxatidine or 20 mg of famotidine at 9 pm, and 12 - 13 h later gastric juice secretion was measured with gastric X-ray films in both groups. Mean gastric juice secretion was significantly lower in the treated groups (roxatidine, 16.1 ml/12 h; famotidine, 19.9 ml/12 h) than in the untreated controls (placebo, 49.5 ml/12 h). Gastric juice suppression by roxatidine and by famotidine, respectively, was 82% and 37% in patients with gastric ulcer; 71% and 39% in patients with duodenal ulcer; 70% and 64% in patients with gastritis; and 68% and 86% in patients with no evidence of disease. It is concluded that roxatidine was more effective than famotidine for gastric juice suppression in patients with peptic ulcer. In patients with no evidence of gastric disease, however, famotidine was more effective than roxatidine.

Adult↗
PubMedDate not supplied

Middle-latency responses of awake and anesthetized Japanese macaques.

The middle-latency response (MLR) of two Japanese macaques were investigated. In the awake state, the configuration of the MLR components showed two positive peaks: Pa and Pb. The latency and the configuration of Pa were very similar to those of humans. In the topographic recordings, the largest Pa amplitude was found from the vertex, or R1, which is 1 cm lateral to the vertex. In the anesthetic state, Pa and Pb gradually disappeared. This study shows that the MLR in awake Japanese macaques is similar to that in humans, and differs from that in cats. Therefore these awake monkeys are suitable as animal models of human MLR.

Acoustic Stimulation↗
PubMedDate not supplied

Changes in otoacoustic emissions in patients with idiopathic sudden deafness.

Transiently click-evoked (TEOAE), distortion product (DPOAE) and spontaneous otoacoustic emissions (SOAE) were recorded and changes in these tests were studied during the recovery process in 15 cases of idiopathic sudden deafness (ISD). In all these cases the amplitudes of TEOAEs and DPOAEs increased concurrently with the recovery of the hearing threshold. Ears with ISD were not different in their OAE characteristics from ears with other forms of sensorineural hearing loss (SNHL). In 4 of the 15 cases, SOAEs could be detected when hearing had recovered. These results suggest that the function of outer hair cells (OHCs) had deteriorated when the hearing threshold was elevated and that OHC activity recovered as hearing improved to nearly normal levels in ISD cases with good outcome.

Adult↗