Search PubMed⌕ Search

Biomedical subjects

T Ohta

Publications and source records attributed to T Ohta.

At least 1,261 records · Page 70Linked to original sources

Effects of consecutive night-shift work on health conditions among car-cleaners of super-express trains.

The Shinkansen Super-Express trains of the Japanese National Railways, the so-called bullet trains, run from early morning until late at night. Accordingly the car-cleaners of the Shinkansen must do late night shift work. A self-administered questionnaire survey including items about health and work conditions was given to 246 workers at Osaka Station, who were then divided into 3 groups: Group A consisted of 102 night workers working 5 successive days with 2 days off, Group B consisted of 124 alternate-day 24-hour workers working 3 days a week, while Group C included 20 day-workers working 6 days a week. A subjective fatigue inventory was administered before and after work for a week to 20 workers selected from each of three groups, group A, B above group D whose shift was 2 times 2 successive night shifts with one day off, and one holiday a week. The results of the questionnaire survey revealed that the rates of complaints such as gastroenteric disorders and general fatigue were the highest in group A. The results of the subjective fatigue inventory show a tendency for the number of complaints in group A and B to increase significantly after the last work shift of the week, but not in the case of group D. The authors demonstrated that there was a close relationship between patterns of night-shift work and various kinds of health problems, and concluded that to insert a day off on the third day of the group D shift was effective in reducing the work load.

Dizziness↗

Transuncodiscal approach to dumbbell tumors of the cervical spinal canal.

A combined anterior and lateral approach to the anterior cervical spinal canal with fusion was performed on five patients with cervical dumbbell-shaped tumors. The procedure consists of anterior discectomy and ipsilateral uncectomy, and removal of the posterolateral corners and posterior transverse ridges of the upper and lower vertebral bodies at the level of the tumor. In the case of a large tumor in the spinal canal, additional removal of a limited segment from the lateral part of the vertebral body was performed. The bone defect was filled with a T-shaped iliac bone graft. Two vertebral bodies were fused in each case. The highest level of the operation was C-2 and the lowest was T-1. The authors believe that any cervical dumbbell-shaped tumor below the C-2 level can be removed via an anterolateral approach as long as no more than three levels of the spine are involved.

Adult↗

Immunological analysis of IgG and other protein fractions in endolymph obtained from endolymphatic sac of Meniere patients and a control.

During endolymphatic sac surgery on patients with Meniere's disease, very small amounts (1 microliter) of the intra-sac endolymph were obtained with micro-glass pipets. An immunological assay of microanalysis of the protein by the single radial immunodiffusion (SRID) method was applied to 2 patients, one with bilateral involvement and the other unilateral. Among the protein fractions Alb, IgG, IgM, IgA, C3, C4, transferrin and alpha 2M, the concentrations of IgG were relatively higher, especially in the Meniere patient in the active stage. From 2 other patients and a control deaf patient with temporal bone fracture, the same amounts of endolymph were obtained, accompanied by a tiny specimen of the outer wall of the sac. When a radio-immunological procedure was applied to the endolymph and the homogenized sac, the specific concentration of IgG was higher in the Meniere patients than in the control.

Albumins↗

[Effects of N-696, a new beta-blocking agent, on canine experimental arrhythmias].

We evaluated antiarrhythmic effects of N-696 using canine digitalis ventricular arrhythmia models and electrophysiological actions of N-696 using canine ventricular muscles and isolated blood perfused A-V node preparations and compared the effects with those of propranolol. 1) N-696 at 30 mg/kg, i.v. was not effective on digitalis arrhythmia, but reduced the total heart rate and atrial rate for 60 min and transiently decreased the blood pressure. Propranolol at 3 mg/kg, i.v. transiently suppressed digitalis ventricular arrhythmia and decreased the total heart rate, atrial rate and blood pressure. The minimum effective plasma concentration of propranolol was 1.7 +/- 0.4 microgram/ml. 2) Ten to 100 micrograms/ml N-696 and 3 to 10 micrograms/ml propranolol did not affect the resting potential and the action potential duration at 75% repolarization of the canine ventricular muscle, but decreased the maximum rate of rise of the action potential in a dose-dependent fashion, and 100 micrograms/ml N-696 decreased significantly the action potential amplitude. The minimum effective drug concentration of N-696 was 60 micrograms/ml, and that of propranolol was 6 micrograms/ml. 3) N-696 (30 micrograms-3mg) dose-dependently delayed the A-V conduction time of the isolated blood perfused A-V node preparation when it was administered into the posterior septal artery (PSA) and the anterior septal artery (ASA). Propranolol (10-600 micrograms) also had similar effects, but the doses of N-696 delaying the A-V conduction time by 15% was about 8 to 21 times higher than those of propranolol.

Adrenergic beta-Antagonists↗

[Morphological study on biopsied skin materials of Lafora disease].

Skin biopsy of a patient with Lafora disease was performed. The specimen showed numerous PAS-positive materials in the eccrine glands as proposed by Carpenter and Karpati. The patient was a 25-year-old man, and his two brothers and sister were diagnosed as Lafora disease by clinical and autopsy findings. The patient has shown typical clinical course of Lafora disease. Light microscopic findings of the skin revealed 5-7 microns oval or round PAS-positive materials in most of the glandular cells in eccrine glands. Several histochemical stainings were applied to the specimens so that the storage materials in the glandular cells were considered as glucose-polymer (polyglucosan). Electronmicroscopic observation showed the materials adjacent to the nucleus without limiting membrane. The materials were composed of numerous glycogen-like particles associated with a small number of fine filaments and vesicles. It have been not clarified why these materials are present in the sweat glands in Lafora disease. Recently skin biopsies have been underwent in patients of storage disease involving the central nervous system. Especially it is much useful for diagnosis of the disease with no reliable enzymatic assays. Pathogenesis of Lafora disease is still unknown. Therefore, skin biopsy might be convenient to differentiate from other types of myoclonus epilepsy.

Adult↗

[The effects of failure of arterial reconstruction on limb status].

During the last 8 years, arterial reconstructive operations such as bypass grafting, thrombendarterectomy and percutaneous transluminal angioplasty were performed on 282 lower extremities with chronic arterial occlusion. Operative indications were intermittent claudication in 57.1% and limb salvage in 42.9%. Early and late failure rate following operations was 31.2%: for claudication group 24.0% and for limb salvage group 40.7%. In 30.6% of claudication group and in 45.7% of limb salvage group, ischemia of limbs, compared to their preoperative status, worsened following occlusion. These limb worsening-rates were high and not negligible. Main causes of failures were poor run off and poor graft. Because chronic arterial occlusion is not a malignant disease, it is not forgivable to worsen limb status by surgery. Therefore, the operative indication for claudicant should be the need of patients in their daily life. For femoro-popliteal bypass grafting in claudicant, not artificial graft but auto vein graft should be used. When no suitable vein is available, conservative therapy is the choice of treatment. In case of limb salvage, artificial graft may be used.

Adult↗

Recognition mechanism of tRNA with tRNA(guanosine-2')methyltransferase from Thermus thermophilus HB 27.

rRNA(Gm)methyltransferase from an extreme thermophile, Thermus thermophilus HB 27 specifically methylates the 2'-OH of the ribose ring of G18 in the invariant G18-G19 sequence in the D loop of tRNA. The interaction site on tRNA was presumed to be the D loop and stem structure. Destruction of tertiary structure of tRNA caused by heat resulted in a great decrease in the acceptor activity of methyl group. It was suggested by CD measurement that a conformational change of tRNA occurs when it forms an equimolar complex with Gm-methylase.

Base Sequence↗

Radioimmunoassay for human pancreatic ribonuclease and measurement of serum immunoreactive pancreatic ribonuclease in patients with malignant tumors.

A method for radioimmunoassay of human pancreatic RNase was developed. The method is sensitive, reproducible, and specific. Almost no cross-reactivity exists between human pancreatic and liver RNases. A good correlation was observed between the serum concentration of pancreatic RNase as measured by radioimmunoassay and its enzymatic activity using polycytidylic acid as substrate. The concentration of serum pancreatic RNase correlates well with age, blood urea nitrogen, and albumin contents but does not correlate with serum amylase activity. Using the data of 52 patients with malignant tumors except pancreatic cancer, serum RNase level could be expressed by a multiple regression equation: Immunoreactive RNase content in pancreatic cancer was elevated in patients with complications from renal failure. Serum pancreatic RNase contents in patients with pancreatic cancer measured by radioimmunoassay agreed well with the values calculated using the equation derived from the data of patients with other malignant tumors.

Humans↗

[A case of cervical intramedullary neurenteric cyst].

A case of cervical intramedullary neurenteric cyst was reported. A 12-year-old girl was admitted with severe pain over the nape and shoulders, and weakness of all extremities. At the age of 4 years, she had suffered from the nape pain and paraparesis which, however, cleared later spontaneously. Neurological examination revealed evidences of presumptive cervical intramedullary lesion, and myelography showed a complete block at the third cervical level accordingly. Surgical exploration through C3-C5 laminectomy disclosed an intramedullary cyst situated within the right half of the cord. The cyst was removed except for its upper and lower apices. Excellent clinical results followed the operation. The cyst was composed of collagen fibers with an inner epithelial lining, which consisted of single or pseudostratified layer of columnar, cuboidal or squamous cells. Cells were ciliated at some parts. The base of the epithelial cells rested upon the basement membrane. Nuclei were positioned near the base of the cells, to present a row. The cytoplasm in the majority of cells contained abundant mucin positive to PAS staining. Pathological diagnosis of neurenteric cyst was made on the basis of these histological findings. Usually intraspinal neurenteric cyst is located in the subarachnoid space and ventrally to the spinal cord. Neurenteric cyst appears histologically similar to ependymal cyst, though, in the latter the epithelial cells seldom contain mucin, and only in scanty amount, if any present. Embryogenesis during the third week of embryonic life was discussed in relation to the development of neurenteric cyst.

Child↗

Radioimmunoassays for two types of human urinary ribonucleases: differential determination of ribonucleases in human serum.

We developed radioimmunoassays for two types of human urinary ribonucleases. The assays are sensitive, reproducible and specific. One human urinary ribonuclease (RNase UL) showed strong immunological identity with human pancreatic ribonuclease, and the other ribonuclease (RNase Us) showed strong immuno cross-reactivity with human liver ribonuclease. There was no immuno cross-reactivity between these two urinary ribonucleases. Serum immunoreactive RNase UL was eluted as four peaks on phosphocellulose chromatography, whereas immunoreactive RNase US was eluted as a single peak. Serum content of immunoreactive RNase UL was 354 +/- 105 ng/ml (mean +/- SD) in normal individuals, and that of immunoreactive RNase Us was 15.9 +/- 5.7 ng/ml (mean +/- SD). No correlation was demonstrated between these two ribonuclease contents in serum.

Adult↗