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Biomedical subjects

Y Shiina

Publications and source records attributed to Y Shiina.

At least 55 records · Page 3Linked to original sources

Studies on the castability of Co-Cr alloy for cast plates. Part 2: Effect of form of sprue attachment to the wax pattern.

Co-Cr alloy is used more frequently than Ni-Cr alloy as a non-precious alloy for cast plates in Japan. However, since the melting point of Co-Cr alloy is very high, about 1300 degrees C, and since it oxidizes easily, a vacuum-pressure casting machine capable of melting this alloy in a reducing atmosphere has recently been developed. Using this vacuum-pressure casting machine, the authors studied the effects on the castability of Co-Cr alloy due to the form of sprue attachment to the wax pattern. The results clarified that in the vacuum-pressure casting method, the form of sprue attachment to the wax pattern has a significant effect (p less than 0.01) on the castability of Co-Cr alloy.

Chromium Alloys↗

[Surgical correction of tetralogy of Fallot with anomalous origin of left pulmonary artery from the ascending aorta].

A surgically corrected case of tetralogy of Fallot with anomalous origin of left pulmonary artery from the ascending aorta is presented. The patient was under-developed 3-year-old girl. She weighed only 1,000 grams at birth and had a systolic heart murmur and slight cyanosis. Echocardiography demonstrated the features of tetralogy of Fallot shortly after birth. Chest roentgenogram showed right ventricular enlargement, but vascular marking of lung was almost normal. Catheterization and cineangiography demonstrated the findings of tetralogy of Fallot. Final diagnosis of anomalous origin of left pulmonary artery from ascending aorta was confirmed by aortography. Surgical correction was accomplished using cardiopulmonary bypass with surface cooling. The left pulmonary artery was detached from the aorta and anastomosed to the main pulmonary artery. Pulmonary valve stenosis and severe infundibular hypertrophy were corrected, and ventricular septal defect was closed with a patch. Postoperative recovery was uneventful. On follow up after surgery, she appears to be in very good condition.

Aorta↗

Reversibility of primary pulmonary hypertension with vasodilator, anticoagulant and nocturnal oxygen therapy.

Successful vasodilator therapy of a 19 year old woman with primary pulmonary hypertension is described. Long-term home oxygen therapy during sleep (2 1/min, 8 hours) in combination with vasodilator drugs (prazosin 2 mg and long-acting ISDN 20 mg bid) and an anticoagulant (ticlopidine 100 mg bid) brought significant reduction of pulmonary artery pressure and a rise of cardiac output 3 years later. This combination therapy may be effective in selected patients with primary pulmonary hypertension.

Adolescent↗

[Effects of prophylactically used latamoxef with tobramycin against postoperative infections on therapeutic drug monitoring and renal function in the field of obstetrics and gynecology].

Latamoxef (LMOX) and tobramycin (TOB) were administered to 50 patients via intravenous drip infusion to prevent postoperative infections in the field of obstetrics and gynecology. Blood levels of TOB were determined, and effects of the combined use of TOB and LMOX on renal functions were clinically studied. The results obtained are summarized as follows: 1. Determination of blood levels of TOB after intravenous drip infusion of 90 mg TOB with 1 g LMOX revealed a peak at the end of drip infusion, and thereafter the levels decreased rapidly. The maximum level and the level upon commencement of the next administration were within the safe range. 2. Clinical laboratory test before and after surgery using markers of renal functions (BUN, creatinine, beta 2-MG and NAG) revealed a tendency for slight increases in BUN and NAG, but no significant differences were shown. 3. There were no abnormalities in other clinical laboratory parameters or any appearance of subjective or objective side effects.

Adult↗

[Surgical management of coarctation of the aorta in early infants].

Thirteen infants under three months old were repaired aortic coarctation between 1980 and 1988. The mean age at operation was 2 +/- 0.8 months, the mean weight was 3.7 +/- 0.6 kg. Patients were simple coarctation in 1, coarctation with VSD in 7, and coarctation with complex heart disease in 5. As the operative method, the prosthetic patch plasty was done in 11 patients, end to end anastomosis in 1 patient and remaining one was primary VSD closure and secondary coarctation repair (patch plasty). Three patients died perioperatively, the overall early mortality rate was 23%. Since the introduction of PGE1 therapy in 1985, operative mortality rate of the operation (patch aortoplasty) was improved dramatically. Two of 10 patients died from LOS after the secondary operation (one was TGA and another was congenital MS with VSD). Eight patients are alive and clinical course after operation had been good. The measurement of arm-leg pressure difference didn't reveal significant residual gradient. Postoperative isthmus index was 90 +/- 13% in follow up measurement. Recoarctation has not been occurred in patients undergoing operations with patch plasty. Postoperative hypoplastic arch index was 93 +/- 19% in 1 to 2 years after operation compared with 70 +/- 16% of the preoperation. Therefore, it is concluded that prosthetic patch aortoplasty and end to end anastomosis of the aorta are both available as reasonable and/or adequate operation for the early infants with coarctation.

Aorta↗

The serum pregnancy-specific beta 1-glycoprotein to beta-human chorionic gonadotrophin ratio as an index of prognosis in patients with choriocarcinoma.

The ratio of serum pregnancy-specific beta 1-glycoprotein (SP1) to the beta-subunit of human chorionic gonadotrophin (beta-hCG) before and after chemotherapy was measured in 12 patients with metastatic choriocarcinoma. The ratios before chemotherapy ranged between 0.03 and 0.75, with a mean value of 0.34 (SD 0.21). The ratio increased to over 1.0 (1.05-53.3) after one or two courses of chemotherapy in seven of the 12 patients. These women achieved complete remission. In the other five patients who died of the disease due to drug resistance of the tumour, the ratio after chemotherapy was low (0.04-0.74) and tended to decline. These data suggest that the serum SP1/beta-hCG ratio can be used to predict the prognosis of patients with choriocarcinoma.

Antineoplastic Combined Chemotherapy Protocols↗

[Histopathological characteristics of stromal cells in trophoblastic disease].

The histopathological characteristics of stromal cells in trophoblastic diseases remain unknown, though determination of malignancy depends on the existence of stromal elements in villi. Thus, we tried to clarify the characteristics and role of stromal cells in the development of diseases. The mitosis index (MI) of stromal cells and cytotrophoblasts, and the frequency of vessels observed in the stroma were examined. The results were as follows: 1) Complete moles were characterized by high MI values for stromal cells and cytotrophoblasts. They were similar to the ones from normal villi. 2) In partial moles, the MI values for both cells were remarkably low. 3) Invasive moles showed low stromal MI and high cytotrophoblastic MI values. 4) The frequency of blood vessels observed in the stroma was low in complete and invasive moles, though it was high in partial moles. The present results which showed histopathological differences in stromal elements in partial and complete moles, may correspond to the difference in their pathogenesis. And it is possible to assume that the decrease in stromal MI values in invasive mole play an important role in the abnormal proliferation of trophoblasts.

Female↗

A case of spontaneous esophageal rupture treated with conservative therapy.

A 51 year-old male was admitted because of abrupt hematemesis and loss of consciousness. Emergency endoscopy depicted a giant esophageal ulcer on the left side extending from the middle intrathoracic region to the lower intrathoracic region. Esophagography, performed on the second day of admission, revealed a huge cavity (10 cm x 7 cm) filled with contrast medium resulting from a rupture in the ulceration. His state of shock improved with conservative therapy and no severe mediastinitis was noted. The drainage from the cavity into the lumen of the esophagus was considered to be acceptable from esophagography and an endoscopic examination. Secondary to his stable condition and continuous drainage, this patient was treated conservatively throughout his clinical course. The patient was given intravenous hyperalimentation (IVH) until the 25th hospital day and was medicated with broad spectrum-antibiotics. On the 21st hospital day the size of the esophageal cavity was markedly decreased (7 cm x 2 cm). Only small irregular mucosa was noted on the esophagogram taken 6 weeks after admission. Six months after the onset, an X-ray examination revealed complete healing of the spontaneous esophageal rupture with no recurrence.

Anti-Bacterial Agents↗

Nonsurgical therapy to preserve oviduct function in patients with tubal pregnancies.

Surgical treatment for tubal pregnancies greatly impairs the subsequent fertility of patients because of salpingectomy and its complicated adhesions. Nonsurgical methotrexate therapy was developed to avoid such complications. Although early detection was of prime importance, resolution of ectopic pregnancy was obtained in 22 patients (95.7%) with methotrexate administration alone. Patency of the oviducts was evaluated with hysterosalpingography and/or laparoscopy in 19 patients after termination of methotrexate treatment. In 10 of 19 patients (52.6%), complete patency of the involved oviduct confirmed the validity of this regimen. Severe side effects were not observed in any of the 23 patients.

Adult↗

Incidence of ovarian metastasis in patients with cancer of the uterine cervix.

During the period from 1970 to 1985, 706 patients with cervical cancer of stage 0 and Ia were treated by a simple hysterectomy without oophorectomy. In 326 patients with invasive carcinoma in stage Ib to stage III, who were treated by a radical hysterectomy from 1977 to 1985, histological examinations were performed to detect ovarian metastasis. A total of 674 autopsy specimens were obtained from the Annual of the Pathological Autopsy Cases in Japan. (Japanese Pathological Society, 1965 to 1978). Follow-up observations on stage 0 and stage Ia revealed no recurrence in the ovaries. In invasive cases of epidermoid carcinoma (stage Ib to stage III), no ovarian metastases were detected, despite discovery of metastases to the pelvic lymph node in 21.6% of the cases. Conversely, in the cases of cervical adenocarcinoma (pure adenocarcinoma and mixed carcinoma), 6 of 48 cases (12.5%) showed ovarian metastases. Ovarian metastases were found in 22 of 77 (28.6%) autopsy cases of adenocarcinoma, but in only 104 of 597 (17.4%) cases of epidermoid carcinoma. This finding is statistically significant (P less than 0.02). Both corpus invasion and metastasis to the ovaries were found in 20 of 54 cases (37.0%). This rate was significantly higher than the rate of ovarian metastasis in cases without corpus invasion (P less than 0.001).

Adenocarcinoma↗

Comparison of the mechanisms of bone resorption induced by 1 alpha,25-dihydroxyvitamin D3 and lipopolysaccharides.

The mechanisms of increase in bone resorption induced by 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] and bacterial lipopolysaccharides (LPS) were compared in an in vitro dead bone assay and a living bone assay. 1 alpha,25(OH)2D3 at concentrations of 0.05-5 ng/ml dose-dependently enhanced the ability of alveolar macrophages to release 45Ca from prelabeled dead bone particles (dead bone assay). In addition, the vitamin promoted fusion of the macrophages to form multinucleated cells and also enhanced glucose consumption, a marker of activation of macrophages. LPS at 0.05-5 micrograms/ml similarly enhanced the release of 45Ca from the dead bone particles and glucose consumption by alveolar macrophages, but it did not induce fusion of the cells at any concentration. Both 1 alpha,25(OH)2D3 and LPS dose-dependently stimulated the release of 45Ca from fetal mouse calvaria prelabeled with 45Ca (living bone assay). Compared to control bone, there were several times as many osteoclasts per given length of trabecular bone surface in calvaria treated for 5 days with either 5 ng/ml of 1 alpha,25(OH)2D3 or 5 micrograms/ml of LPS. Indomethacin (10(-5) M) completely inhibited the LPD-induced increase of osteoclasts, but not the 1 alpha,25(OH)2D3-induced increase. These results suggest that 1 alpha,25(OH)2D3 and LPS similarly stimulate bone resorption by activating macrophages as well as by promoting fusion of precursor cells to form multinucleated cells. 1 alpha,25(OH)2D3 induced formation of multinucleated cells with bone-resorbing activity directly, whereas LPS appeared to induce multinucleated cells through prostaglandin synthesis by some other types of cells present in living bone tissues.

Animals↗