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Biomedical subjects

Y Umezu

Publications and source records attributed to Y Umezu.

16 recordsLinked to original sources
PubMed1992

Histochemical and immunological analyses of differentiating skeletal muscle fibers of the postnatal rat.

Fiber type differentiation as revealed by myosin ATPase activities and the immunological analysis of myosin light chains (MLC) by the Western blotting method were done on the postnatal rat soleus and extensor digitorum longus (EDL) muscles. In the soleus, type 1 (slow-twitch) muscle fibers gradually increase in percentage after postnatal day 10, and, in the EDL, the differentiation of type 2A and 2B (fast-twitch) muscle fibers is also pronounced between postnatal days 10 and 15. The present immunological analysis of MLC indicates that the antigenicity of Lc1S becomes more intense with a rapid decrease in antigenicity of Lc2F from postnatal day 7 in the soleus, while the antigenicity of Lc1F becomes noticeable during the same period in the EDL. These results suggest that the differentiation of slow-twitch fibers is mainly due to that of Lc1S in the soleus and the differentiation of fast-twitch fibers is mainly due to that of Lc1F in the EDL.

Age Factors↗
PubMed1992

[A case of ruptured aortic arch aneurysm into the lung].

Successful surgical treatment of aortic arch aneurysm ruptured into the left lung was reported. The patient was a 74-year-old man suffering from recurrent hemoptysis. Computed tomography and aortic angiography demonstrated a giant aortic arch aneurysm. Emergency operation was performed. Arch reconstruction by a Dacron graft was performed with hypothermic circulatory arrest. The post operative course was uneventful and there was no evidence of cerebral complication. In the emergency operation for ruptured aortic arch aneurysm, hypothermic circulatory is very useful method for cerebral protection.

Aged↗
PubMed1991

Corneal edema induced by bis (tributyltin) oxide.

Corneal edema induced by bis (tributyltin) oxide (TBTO) was studied with an electron microscope and the accumulation sites of tin were determined with an X-ray microanalyzer. Male Wistar rats received an intramuscular injection of 0.5 ml/kg TBTO. After time intervals of 2, 4, 6, 8, 10, 12 h after injection, corneas were isolated and provided for electron microscopy. Corneas from untreated rats served as controls. Marked swelling of mitochondria in the corneal endothelial cells occurred at 4 h after TBTO injection. The corneal edema appeared in the endothelial layer and the stroma at 6 h after injection. By X-ray microanalysis, Sn peaks were obtained from swollen mitochondria in the endothelial cells. At 12 h after TBTO injection, edematous swelling of the corneal tissue became more advanced. These results indicated that parenterally administered TBTO accumulated in the mitochondria of corneal endothelial cells. The direct toxic effects of TBTO on the mitochondria might cause the interference with active pump function of endothelial cells and induced the corneal edema.

Animals↗
PubMed1991

Cadmium toxicity in the thyroid gland of pregnant rats.

The toxic effects of cadmium on the thyroid gland of pregnant rats were studied with an electron microscope and an X-ray microanalyzer. Serum levels of thyroid hormones (T3 and T4) were also analyzed. Deterioration of the rough-surfaced endoplasmic reticulum occurred in the thyroid follicular epithelium on the fifth day of cadmium treatment. Large intracellular vacuoles, which arose from dilated cisternae of the rough-surfaced endoplasmic reticulum, were fused together, and marked swelling of the mitochondria was also noted. Thyroglobulin-secreting granules at the apical cytoplasm were decreased in number. By energy dispersive X-ray microanalysis, cadmium peaks were preferentially obtained from swollen mitochondria in the follicular epithelial cells. Serum levels of T3 and T4 were significantly decreased in cadmium-treated rats dams when compared to those of controls. In the present experiment, cycloheximide also caused degenerative changes in the rough-surfaced endoplasmic reticulum and the disappearance of thyroglobulin-secreting granules. Cycloheximide is a known inhibitor of protein synthesis on cytosolic ribosomes. These results indicated that accumulated cadmium in the mitochondria of thyroid follicular epithelial cells might disturb the oxidative phosphorylation of this organelle and the loss of energy supply possibly caused the inhibition of the synthesis and release of thyroid hormones.

Animals↗
PubMed1990

Histopathological findings in the biopsied muscle of a juvenile type III glycogenosis.

We report a case of juvenile type III glycogenosis that was confirmed by histopathological and biochemical studies. The histopathological findings consisted of vacuoles, periodic acid-Schiff positive materials, type 2B fiber deficiency, mildly positive acid phosphatase reaction and intensely positive non-specific esterase reaction. It is suggested that the enzyme reactions may be related to membrane-bound sacs containing glycogen.

Acid Phosphatase↗
PubMed1990

Acetylcholinesterase activity of developing muscles in the lower limb of the rat.

A cytochemical study of acetylcholinesterase was done in the lower limb of the prenatal rat and in the gastrocnemius muscle of the postnatal rat. Between 15 and 17 days of gestation, mesenchymal cells constituting the muscle primordia are characterized by the presence of enzyme activity in their rough endoplasmic cisterns and nuclear envelopes, while those involved in the formation of the neocapillary and cartilage do not show enzyme activity. This suggests that mesenchymal cells destined to myogenic cells actively produce acetylcholinesterase in a limited period, which may play a role in cellular aggregation and fusion during the muscular morphogenesis. Cytochemical findings as to extensive networks of secondary synaptic folds of the neuromuscular junctions and invaginations of the sarcolemma in the extrasynaptic regions are also illustrated in the differentiating gastrocnemius muscles.

Acetylcholinesterase↗
PubMed1990

[A case report of ball variance of Smeloff-Cutter prosthetic valve].

A 37-year-old woman had undergone aortic valve replacement with Smeloff-Cutter prosthetic valve in 1967. She visited our hospital because of dyspnea and chest pain about 22 years after the operation. Severe aortic regurgitant murmur was audible and a chest X-ray demonstrated lung edema. A diagnosis was made of acute left heart failure due to prosthetic valve dysfunction, and emergency operation was performed. The Silastic ball was severely deformed and shrunken. Therefore, the ball was easily put off outside the cage. A St. Jude medical prosthetic valve was implanted. The postoperative course was uneventful.

Adult↗
PubMed1990

[Intrathoracic pacemaker implantation in children].

In order to minimize the complications, we introduced the intrathoracic implantation method since 1976. Until 1988, 12 children underwent this method. A pacemaker generator was exchanged in 8 patients, 12 times, because of battery exhaust. Compared with the conventional method (abdominal wall implantation), the complications such as electrode fracture, which was related to the implantation sites, were reduced. Furthermore it was very useful from the cosmetic viewpoint. Although an exchange of generator was very easily done at the first time, it was very difficult at the second time, due to rib fusion accompanying with children's growth.

Adolescent↗
PubMed1989

Ultrastructural findings in the wound healing of the colonic mucosa of rabbits.

The wound healing of the rabbit colonic mucosa after experimental excision was observed with the electron microscope. Between 5 and 7 days, considerable numbers of undifferentiated mesenchymal cells (group I), differentiating muscle cells (group II) and histiocyte-like cells (group III) appear in the regions where the muscularis mucosae is re-establishing. Our electron micrographs indicate that group I cells are stem cells which differentiate to group II cells involved in muscle regeneration or to group III cells involved in phagocytosis. The mitotic proliferation of pre-existing smooth-muscle cells at the ulcer margin does not seem to be the major reason for the re-establishment of the muscular layer. Multinucleated cells occurring in this healing mucosa are considered to be formed by successive fusions between the group III cells and to play a role in enclosure of cell debris such as fragments of elastin.

Animals↗
PubMed1989

[A case of pulmonary infarction secondary to subacute bacterial endocarditis with subpulmonary VSD].

A case of pulmonary infarction secondary to subacute bacterial endocarditis of pulmonary valve which is associated with subpulmonary VSD is presented. The jet stream of blood through the subpulmonary VSD made damage to the pulmonary valve, which may be one of the reasons why subacute bacterial endocarditis was associated with the subpulmonary VSD. Echocardiography of the right-sided valves will be very useful in order to detect the pulmonary valve endocarditis in congenital heart disease presenting with fever.

Adult↗
PubMed1989

[Surgical consideration of ruptured abdominal aortic aneurysms].

During the recent 18 and a half years, 30 cases of ruptured abdominal aortic aneurysm (including four cases of A-V fistula) were operated at Saiseikai Utsunomiya Hospital. In 26 cases, a conventional graft replacement was performed. In other four cases, axillo-bifemoral bypass (in the cases ruptured into the colon) or other methods were used. Overall operative mortality rate was 26.7%. However, during the last 9 years, operative results were improved (21.7%, 5 deaths out of 23 cases). Amount of intraoperative blood loss influenced the operative results greatly. Other operative risk factors included preoperative shock, preoperative severe cerebrovascular or cardiovascular complications, and postoperative thromboembolism. Factors of recent improvement in mortality included; establishment of emergency system which resulted in earlier operation after the patient's arrival at the hospital, use of occlusive balloon for bleeding control, heparin administration before the aortic clamp for preventing peripheral thromboembolism and introduction of autotransfusion system for reducing the amount of blood transfusion.

Adult↗
PubMed1987

[Quality control of radioimmunoassay for TSH, LH, FSH, C-peptide, prolactin based on NIH-computer program].

As there has been no data available on the variation of RIA through a year, we assessed within kit and component of between assay variation of TSH, LH, FSH, C-peptide and PRL kit through a year (more than 12 sequential assays). The average of within kit variation was 6.9% (ranged from 4.7 to 9.8%) and that of component of between assay variation was 11.2% (ranged from 8.9 to 14.5%). These values were almost similar to those obtained for the within kit variation and component of between assay variation employing single lot of kit. These results warrant that quality of kits produced by manufacturers was homogeneous throughout the observation period.

C-Peptide↗
PubMed1986

Dual-energy projection radiography using condenser x-ray generator and digital radiography apparatus.

The authors describe a system for dual-energy projection radiography using a modified condenser-type x-ray generator and a digital radiography unit. High- and low-energy images are obtained within a practical exposure interval. This method provides better visualization of soft tissues that are otherwise obscured by skeletal structures and also allows better visualization of bone and calcifications (e.g., calcified nodules in the lung) without interference by overlying soft tissue.

Humans↗
PubMed1985

Decrease in human growth hormone (HGH) levels during transsphenoidal surgery for acromegaly as a guide for prognosis.

To evaluate the clinical significance of human growth hormone (HGH) dynamics during transsphenoidal microsurgery for acromegaly, serial HGH levels during the surgery were compared with the post-operative basal HGH levels in 15 acromegalic patients, retrospectively. In all patients, in whom the HGH level immediately after tumor resection was reduced below 5 ng/ml or the decreasing rate which stood for the magnitude of decrease of HGH during resection procedure was above 80%, postoperative permanent HGH levels fell to below 5 ng/ml, namely, within the normal range. The rapid radioimmunoassay (RIA) of HGH was developed by the use of high affinity antibody in order to inform the surgeons of plasma HGH levels quickly during the surgery. It is now possible to know HGH levels about 1 hour after submitting the samples. It was verified that HGH levels measured in the rapid RIA correlated well with those obtained in the conventional way. The rapid RIA method was applied to 6 patients and the correlation between HGH levels during the surgery and post operative levels was also studied prospectively. The results were essentially identical to those in a retrospective study. It was suggested that the HGH level immediately after tumor resection and the extent of the decrease in HGH during the resection procedure were good indicators of the prognosis of surgical results in acromegaly and the rapid RIA method was useful in order to judge HGH levels quickly during the surgery.

Acromegaly↗