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Biomedical subjects

R Saito

Publications and source records attributed to R Saito.

At least 217 records · Page 12Linked to original sources
PubMed1991

The use of visible light-curing resin for vertebral body replacement.

The technology of visible light-curing resin has recently been developed for use in removable prosthodontics. A quartz halogen lamp producing a 400- to 500-nanometer wave-length spectrum of visible light is used to polymerize high-molecular-weight acrylic resin monomers. While several in vitro and in vivo studies of visible light-curing resin are found in the dental literature, no studies have yet been performed to evaluate it as an intracorporeal implant in surgery. The authors have designed a rat model of microcervical corpectomy to assess vertebral body replacement with visible light-curing resin in comparison to conventional autopolymerizing methyl methacrylate. Spinal cord function tests, spinal-implant stability assessments, and histological evaluations were made in a total of 41 rats at 2, 4, or 6 months postimplant. No animal developed a neurological deficit or radiographic instability, and at sacrifice there was no evidence of implant fracture-extrusion. In addition, there were no signs of adverse reaction in the surrounding tissues. Morphological investigation of the resin/bone interface at 6 months revealed very good implant anchorage. Visible light-curing resin was found to be far superior to methyl methacrylate for construction of spinal implants. Its waxy consistency makes it easy to handle. It remains pliable until light is applied, allowing adjustments in shape for a well-fitted implant without time constraints. Applied in layers, adjustments can be made even after polymerization of a previous layer. This new implantable resin will allow safer, immediate stabilization in patients with neoplastic destruction of the spine, and may also be advantageous for other neurosurgical applications, such as cranioplasty.

Animals↗
PubMed1991

Contractile activity of Trimeresurus flavoviridis phospholipase A2 on guinea pig ileum and artery.

Trimeresurus flavoviridis phospholipase A2 (PLA2) induced strong contractions of the smooth muscles of guinea pig ileum and artery in a concentration-dependent manner (10(-10)-10(-6) M). When the same dose of PLA2 was administered in repetition to the ileal preparation, the contraction diminished progressively and was no longer recovered even by consecutive washings. The enzymatically inactive derivative of PLA2, in which His-47 was p-bromophenacylated, was unable to elicit contraction. Also, no activity was observed when the Ca(2+)-free medium was used. The contraction induced by PLA2 was inhibited completely by 1.0 x 10(-6) M indomethacin, but not by nordihydroguaiaretic acid. These results imply that the PLA2-induced contraction is due essentially to the hydrolytic action of the enzyme against phospholipid membranes to liberate arachidonic acid that is then converted to pharmacologically active prostaglandins. In guinea pig artery, PLA2 caused both contraction and relaxation.

Animals↗
PubMed1991

[The smoking habits of pregnant women and their husbands, and the effect on their infants].

A survey of the smoking habits of 3,025 couples, whose infants were receiving medical examinations, was conducted before and after pregnancy to determine the effect of smoking patterns of the parents on the newborn infant. Of the husbands 55.2% were smoking before pregnancy; 53.4% during pregnancy; and 51.8% after delivery. During pregnancy proportion of smokers decreased by only 1.8%. The percentages for wives, on the other hand, were 13.9%, 4.4%, and 5.3% respectively showing a reduction of 9.5% during pregnancy. Young couples, under 24 years of age, those with low educational backgrounds, and self-employed husbands showed the highest proportion of smokers. Examination of the relation between parents' smoking habits and their effect on the newborn infants, showed no difference in weeks of gestation nor in height. However, the infants of smoking parents were on the average 99.6 grams lighter at birth (p less than 0.02) and the rate of SFD was higher (p less than 0.05). The relative risk for SFD appearance was 1.21 with a smoking father, and 1.39 with both parents smoking. Husbands who decreased or stopped smoking during the pregnancy were largely in the 30 to 34 year old category, university graduates, and those whose wife was having their first baby. A remarkable decrease was observed in the average weight at birth of infants with a mother smoking 6 cigarettes a day or with father smoking 20 cigarettes a day compared to non-smoking parents, especially in the case of female infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Differential diagnosis of gastric adenoma and type IIa early gastric cancer.

The endoscopic and radiographic findings of 45 gastric adenomas in 39 patients were followed for 6 months to 13 years and compared with type IIa early gastric cancer observed in 9 patients. Difficulties in the differential diagnosis of these disorders were evaluated. The following features were suggestive of gastric adenomas: clustered lesion; protuberance with gentle slope; smooth surface; and relatively young patients. Discrimination of adenoma from type IIa early gastric cancer is often difficult by visual observation alone; biopsy was essential in most patients. A group III adenoma verified on biopsy should be followed closely because the lesion may harbor a cancer (so-called carcinoma-in-adenoma) or a cancer may later develop.

Adenoma↗
PubMed1990

Characterization of tachykinin receptors in endothelial cells of porcine artery.

The binding of iodine-labeled Bolton-Hunter substance P (125I-BHSP) to porcine endothelial cell membranes was examined. The endothelial cells had a single high-affinity binding site with a dissociation constant of 0.10 nM, and a maximum number of binding sites of 52.2 fmol/mg protein. The relative potencies of various tachykinins to displace the binding of 47 pM 125I-BHSP suggested that endothelial cells of porcine aorta contain the NK-1 subtype of tachykinin receptor. A GTP analogue, guanyl-5'-yl imidodiphosphate, induced marked reduction in the number of 125I-BHSP binding sites suggesting that these binding sites are coupled with GTP-binding protein.

Animals↗
PubMed1990

Detection of peripheral blood and bronchoalveolar lavage fluid lymphocytes in rat lung transplantation for early diagnosis of rejection.

Left lung transplantation was performed in two combinations of rat strains. In group 1, lung grafts were rejected within 7 day postoperatively, and in group 2, grafts were rejected within 18 day postoperatively. The histological appearance of rejection was classified into 4 stages, and lymphocytes from peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) were collected at each stage. In group 1, a significant decrease in the number of lymphocytes in PB was observed as the rejection progressed, whereas the number of lymphocytes in PB increased slightly in group 2. The number of total cells in BALF increased significantly as the rejection progressed in both groups. A marked increase in the value of spontaneous blastogenesis (SB) was observed in stage 2 in BALF lymphocytes, whereas that in PB lymphocytes was found to increase after stage 3 in both groups. The ratio of T-helper/T-nonhelper did not change significantly in PB lymphocytes in both groups. On the other hand, a significant decrease in the value of T-helper/T-nonhelper (less than 1.0) was observed in BALF at stage 3 and 4 in both groups. These results show that the studies of BALF lymphocytes were very useful for early diagnosis of rejection in lung transplantation.

Animals↗
PubMed1990

Ceruminoma with intracranial invasion--case report.

Ceruminous gland tumors (ceruminomas), which usually involve the external auditory canal, are rare. A case of ceruminoma invading the temporal bone and histologically proven to be papillary adenoma is presented. The tumor recurred and invaded intracranially after subtotal removal and was finally diagnosed as adenocarcinoma. The importance of early diagnosis and radical treatment is stressed.

Adenocarcinoma↗
PubMed1990

[OKT4 epitope deficiency in a patient with thymoma and hypogammaglobulinemia].

A 61-year-old male stonecutter was in excellent health until December 1988 when he was admitted to Miyagikenritsu Semine Hospital with an abnormality on chest X-ray film. Chest X-ray film revealed a left anterior mass that was confirmed on chest CT scan and MRI. Biochemical examinations and serum protein electrophoresis demonstrated hypoproteinemia (5.4 g/dl) and hypogammaglobulinemia (7.9%, 0.43 g/dl). Lymphocyte subset analysis showed OKT4 epitope deficiency (OKT4 0.1% and Leu3a 28.4%), and decrease of CD4/CD8 ratio (0.65). An encapsulated anterior mediastinal mass and the thymus were resected on January 9, 1989, without difficulty. Histology revealed a thymoma with a spindle cell epithelial component. OKT4 epitope deficiency in a patient with Good's syndrome (thymoma with hypogammaglobulinemia) was our diagnosis. There was no change in the patient's serum immunoglobulin level after thymectomy. Fifteen cases of Good's syndrome have been reported in Japan, but this is the first report of OKT4 epitope deficiency with Good's syndrome in Japan.

Agammaglobulinemia↗
PubMed1990

Prognostic factors in liver metastases after transcatheter arterial embolization or arterial infusion.

From January 1986 to December 1988, 85 patients (55 men and 30 women, mean age 59 years) with metastatic liver tumors were treated with hepatic artery embolization (TAE) or infusion (HAI). Sixty-eight patients with successful catheterization were treated with TAE using iodized oil (Lipiodol) mixed with anticancer agent (ACA). In 12 of 68 patients with hypervascular tumors gelatin sponge was added. Patients with unsuccessful catheterization were treated with hepatic artery infusion of ACA. Forty-three patients received oral chemotherapy following TAE or HAI. Overall, the 6-month, and 1- and 2-year survival rates were 69.5, 31.8 and 4.1 per cent, respectively (mean 233 days). A univariate analysis of prognostic factors showed that number of metastases, stage, treatment times and oral chemotherapy were all significant factors (p less than 0.05). Ascites, jaundice, percentage of hepatic replacement and treatment protocol also had some influence (p less than 0.1). Sex, age, primary site, elevation of tumor markers, other metastatic lesions, portal vein involvement and difference in anticancer agent had no prognostic significance. A multivariate analysis using Cox's proportional hazard model revealed that the number of treatments had the most important prognostic significance, followed by oral chemotherapy, stage and percentage of hepatic replacement.

Antineoplastic Agents↗
PubMed1990

[Clinicopathologic assessment of esophageal cysts--a report of 8 cases].

We experienced 8 cases of esophageal cysts on between January, 1965 and March, 1989. During the same period, 320 cases of mediastinal tumors were operated in our department, and esophageal cysts were 2.5% of these cases. They were 7 males and 1 female, and ranged in age from 5 to 51 (mean 29.9) years. The cysts were located in the right in 6 and in the left in 2, and in the upper third of the esophagus in 1, middle third in 3 and lower third in 2 cases. A correct preoperative diagnosis was made in only 1 case. The definite diagnoses were not obtained from thoracic CT scans and esophagography. We tried transesophageal ultrasonic endoscopy in the recent 2 cases, and could diagnosed in 1 case as a cyst in the esophageal wall. The another case, we could not diagnose, was a cyst attached to the esophageal wall by a muscular stalk. We experienced 2 cases of post operative bleedings, so we must be careful of hemostasis of the muscular layers after enucleation of the cysts. Histological examinations of the cysts showed ciliated columnar epithelium in all cases. Cartilage were observed (bronchogenic cysts) in 4 patients (50%) and two muscle layers were observed (duplication cysts) in 4 other patients (50%). But 2 cases of bronchogenic cysts had two muscular layers, 1 case of them was well-defined. And 1 case of duplication cyst had poor two muscular layers. We cannot divide clearly the esophageal cysts into bronchogenic cyst or duplication cyst, in the point of having cartilage and double muscle layers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

No enhancement by phenobarbital of the hepatocarcinogenicity of a choline-devoid diet in the rat.

An experiment was performed to test whether inclusion of phenobarbital in a choline-devoid diet would increase the hepatocarcinogenicity of the diet. Groups of 5-week old male Fischer-344 rats were fed for 7-25 months semipurified choline-devoid or choline-supplemented diets, containing or not 0.06% phenobarbital. No hepatic preneoplastic nodules or hepatocellular carcinomas developed in rats fed the plain choline-supplemented diet, while one preneoplastic nodule and one hepatocellular carcinoma developed in two rats fed the same diet containing phenobarbital. The incidence of preneoplastic nodules and of hepatocellular carcinomas was 10% and 37%, respectively, in rats fed the plain choline-devoid diet, and 17% and 30%, in rats fed the phenobarbital-containing choline-devoid diet. The results evinced no enhancement of the hepatocarcinogenicity of the choline-devoid diet by phenobarbital. Sporadic neoplastic lesions were observed in organs other than the liver of some of the animals, irrespective of the diet fed.

Animals↗
PubMed1989

Clinical effects of cepharanthin (Ceph.) on leukopenia by chemotherapy in lung cancer patients.

In order to examine the clinical efficacy of cepharanthin (Ceph.) for preventing leukopenia caused by chemotherapy in lung cancer patients, a randomized trial was carried out. Subjects were 45 patients with non-small cell lung cancer (NSCLC) receiving initial treatment with cisplatin (CDDP) +adriamycin (ADM) +mitomycin C (MMC). Ceph. was given at a dose of 1 mg/kg to the administration group (Ceph. group) and changes in the peripheral leukocyte count were examined in both the Ceph. and non-Ceph. groups. The Ceph. group showed a reduction in the number of cases with a count nadir less than 3,000/microliters (p less than 0.05), a shortening of the time that leukocyte counts stayed under 2,000/microliters, corresponding to the time in which granulocyte counts were less than 500/microliters (p less than 0.05), and also a reduction of the time for leukocyte counts to recover from nadir to 2,000 or 3,000/microliters (p less than 0.05) measured from the commencement of chemotherapy. These results suggest that administration of Ceph. has an antileukopenic effect in anticancer treatment, and makes it possible to reduce the period of risk for infection, allowing effective regimens to be administered repeatedly in shorter intervals.

Adult↗
PubMed1989

[Angiographic positions for thoracic outlet syndrome].

Thirty four patients (18 males and 16 females, 54 lesions) with thoracic outlet syndrome (TOS) were studied with conventional angiography. Angiography in the supine position did not confirm subclavian artery compression in 43.4% of patients. Lordotic position or upright position was useful for demonstration of subclavian artery compression in patients who did not show any findings in conventional techniques.

Adolescent↗
PubMed1989

Dimeric substance P analogue shows a highly potent activity of the in vivo salivary secretion in the rat.

We have synthesized a dimeric analogue of substance P (SP) COOH-terminal nonapeptide fragment (D-SP-(3-11] and examined the in vivo and in vitro biological activities in the submaxillary gland of the rat. The dimer elicited an enhanced biological response as compared with receptor binding, showing 2.4-fold more potent receptor affinity than its monomer and 75-fold more potent in vivo salivary secretion activity.

Animals↗
PubMed1989

Electrical resistance of appliances as a cause of urethral stricture following transurethral resection of prostate.

We performed transurethral resection for prostatic hypertrophy on 128 patients, and encountered 6 causes of postoperative urethral stricture. As they occurred during a short period, we investigated the causes. An electrical check revealed electrical resistance of more than 10,000 omega in the electric cord of a resectoscope. When an unused loop was connected with three used cords (No. 1, 2 and 3) and a new cord, the resistances were 2,000, 5,000, 0.9 and 0.5 omega, respectively. Moreover, the respective resistances were 15,000, 1,150,000, 1.3 and 0.9 omega when a used loop was tested. These findings suggested that the excessive resistance resulted from the use of a worn cord and that the used loop caused the postoperative urethral stricture.

Electric Conductivity↗
PubMed1989

Toxic megacolon in cytomegalovirus colitis.

We report a case of toxic megacolon manifesting in cytomegalovirus (CMV) colitis in a 55-yr-old man with steroid-dependent chronic obstructive pulmonary disease. He presented to the hospital with increasing dyspnea and low-grade fever. His hospital course was characterized by the poor response of his symptoms to treatment, and by the subsequent development of intermittent hematochezia and, eventually, acute abdomen. The surgical specimen showed dilatation of the cecum and ascending colon with a solitary mucosal ulcer in the latter. The major histologic changes were limited to the area of ulceration. In addition to classical CMV inclusions. vasculitis manifested in two forms, namely, leukocytoclastic type and fibrinoid necrosis. The patient died shortly thereafter, due to multi-organ system failure. To our knowledge, this represents the first reported case of toxic megacolon due to CMV infection without underlying inflammatory bowel disease. The pathogenesis of toxic colonic dilatation remains unknown.

Colitis↗