Search PubMed⌕ Search

Biomedical subjects

S Kitano

Publications and source records attributed to S Kitano.

At least 253 records · Page 14Linked to original sources
PubMed1994

[Image analysis of optic disk swelling in diabetic retinopathy].

Optic disc swelling was measured by computerized image analysis in diabetic patients. The subjects were divided into four groups. Group 1 contained 13 eyes without diabetic retinopathy, group 2, 14 eyes with a mild stage of simple diabetic retinopathy, group 3, 14 eyes with a severe stage of simple diabetic retinopathy and group 4, 14 eyes with preproliferative diabetic retinopathy. There were statistically significant differences in the optic disc swelling between group 1 and group 4, and between group 2 and group 4 (p < 0.05). The optic disc swelling increased as the stage of diabetic retinopathy progressed.

Diabetic Retinopathy↗
PubMed1994

Laparoscopy-assisted Billroth I gastrectomy.

Laparoscopic distal partial gastrectomy is still technically difficult under conditions of a pneumoperitoneum because of the lack of appropriate techniques and laparoscopic instruments. We describe here a technique of laparoscopy-assisted Billroth I gastrectomy under an abdominal wall-elevating method.

Aged↗
PubMed1993

Calciseptine binding to a 1,4-dihydropyridine recognition site of the L-type calcium channel of rat synaptosomal membranes.

Calciseptine (CaS) is a natural peptidic L-type Ca2+ channel blocker consisting of 60 amino acids with four disulfide bonds. The effects of synthetic CaS on the binding of various ligands to Ca2+ channels of rat brain synaptosomal membranes were studied. The membranes possessed specific binding sites for L-type Ca2+ channel ligands [3H]nitrendipine, [3H]diltiazem and [3H]verapamil, derivatives of 1,4-dihydropyridine, benzothiazepine and papaverine, respectively, and also for N-type Ca2+ channel ligand omega-[125I]-conotoxin GVIA (omega-[125I]CTX). Lineweaver-Bulk plot analysis disclosed that CaS competitively inhibited the binding of [3H]nitrendipine, with maximal binding capacity of 0.19 pmol/mg protein and dissociation constant (Kd) of 290 nM, being about 10(3) times the Kd value of [3H]nitrendipine. Similar to nitrendipine, CaS noncompetitively enhanced the binding of [3H]diltiazem, but did not affect the binding of [3']verapamil. CaS at up to 10.0 microM did not affect the binding of omega-[125I]CTX. These observations indicate that CaS shares the properties of 1,4-dihydropyridine derivatives, and allosterically modulates the binding of other L-type Ca2+ channel ligands.

Animals↗
PubMed1993

Tumor necrosis factor-alpha induces expression of monocyte chemoattractant JE via fos and jun genes in clonal osteoblastic MC3T3-E1 cells.

The mechanism by which circulating monocytes are attracted to sites of bone remodeling is unknown. We now report that tumor necrosis factor-alpha (TNF-alpha), a potent osteotrophic cytokine, was stimulatory for expression of the monocyte chemoattractant JE gene in osteoblastic MC3T3-E1 cells. TNF-alpha stimulated this JE gene expression transcriptionally. The presence of JE gene product in conditioned medium of the cytokine-treated cells was evidenced by an immunoprecipitation assay with antiserum specific for JE/MCP-1. The stimulated JE gene expression was markedly inhibited by H-7, a potent inhibitor of protein kinase C. Phorbol 12-myristate 13-acetate induced the JE gene expression, and the cytokine-induced JE gene expression was down-regulated by the phorbol ester pretreatment. TNF-alpha induced expression of both early protooncogenes, c-fos and c-jun, in the cells. Antisense oligonucleotides to these oncogenes significantly inhibited the cytokine-induced monocyte chemotactic activity. Furthermore, curcumin, a specific inhibitor of c-jun/AP-1, markedly inhibited JE gene expression and monocyte chemotactic activity induced by the cytokine. These results suggest that TNF-alpha may contribute to the regulation of remodeling and inflammation of bone tissues through the JE gene product.

3T3 Cells↗
PubMed1993

N-acetyl-D-galactosamine inhibits TNF-alpha gene expression induced in mouse peritoneal macrophages by fimbriae of Porphyromonas (Bacteroides) gingivalis, an oral anaerobe.

Adherence to host cells is an essential step in the initiation of most infectious diseases. It is well known that bacterial fimbriae may be involved in the adherence. Porphyromonas (Bacteroides) gingivalis is a pathogenic organism of adult periodontitis which is a chronic inflammatory disease. Using an experimental system for fimbria-induced TNF-alpha gene expression in mouse peritoneal macrophages, we examined the role of sugar moieties in the adhesion of P. gingivalis fimbriae to these cells. The fimbriae strongly induced TNF-alpha gene expression in the macrophages, and marked TNF activity toward fibroblasts was observed in culture supernatants of the fimbria-treated cells. The potent expression of TNF-alpha was inhibited by N-acetyl-D-galactosamine, but not inhibited by D-mannose, alpha-lactose, and alpha-L-rhamnose, D-galactose, and N-acetyl-D-glucosamine.

Acetylgalactosamine↗
PubMed1993

[Usefulness of superparamagnetic iron oxide particles in the detection of hepatocellular carcinoma by MR imaging].

Eight patients with histologically or clinically diagnosed hepatocellular carcinoma and a total of 23 nodules were studied. SE 2000/20 (PDW-SE), SE-2000/80 (T2W-SE), SE 500/20 (T1W-SE), GRE 167/13/70 degrees (T1W-GE), and GRE 167/13/15 degrees (T2*W-GE) were used. Using each pulse sequence the pre-and post-contrast detection rates of the 23 nodules visualized by CT arterial portography (CTAP) were compared. With plain MRI, the detection rates were PDW-SE: 48%, T2W-SE: 74%, T1W-SE: 52%, T1W-GE 48% and T2*W-GE: 48%. After the administration of contrast medium all pulses sequences showed enhanced detection rates: 100%, 83%, 87%, 91%, and 96% respectively. Superparamagnetic iron oxide particle enhanced MRI showed a high detection rate comparable to CTAP, suggesting that this agent can make a major contribution to the diagnosis of HCC, particularly the detection of small HCC.

Carcinoma, Hepatocellular↗
PubMed1993

IL-1 induces expression of monocyte chemoattractant JE in clonal mouse osteoblastic cell line MC3T3-E1.

Recent studies demonstrated that platelet-derived growth factor-inducible JE is an inflammatory cytokine that directs chemotaxis of monocytes, and is a homolog of monocyte chemoattractant protein-1, which is a human monocyte chemotactic factor. Migration and accumulation of monocyte lineage cells in bone tissue sites are very important for the recruitment of multinucleate osteoclasts, because the origin of osteoclasts is derived from monocyte lineage cells in hemopoietic cells. Because IL-1 is a potent regulator in bone remodeling, we examined whether IL-1 beta induces JE expression in a clonal mouse osteoblastic cell line, MC3T3-E1. Significant chemotactic activity for human monocytes was detected in conditioned medium of the cells at 6 h after initiation of IL-1 beta treatment, and the chemotactic activity increased in both a culture time- and dose-dependent manner. The peak of the chemotactic activity in the conditioned medium was observed in fractions corresponding to a m.w. of 26 kDa when the conditioned medium was fractionated by gel filtration. The chemotactic activity in the peak fraction was completely neutralized by antiserum specific for JE protein. And the JE gene product in the conditioned medium was detected as a microheterogeneous protein with a m.w. of 21 to 33 kDa by immunoprecipitation with the specific antiserum. IL-1 beta induced a maximal JE gene expression in the cells at 3 h after initiation of the cytokine treatment. This significant expression was observed when IL-1 beta was used at a concentration of 10 U/ml, and the expression was dose dependent. The run-on assay showed that the cytokine-induced JE gene expression increased at the transcriptional level. IL-1 beta and TNF-alpha acted synergistically to stimulate JE gene expression in the cells. Expression and product of the JE gene were also observed in an osteoblast-enriched cell population prepared from mouse calvariae. These results suggest the possibility that osteoblastic cells can participate in osteoclast recruitment via the JE gene product.

Animals↗
PubMed1993

The effects of indomethacin and thiorphan on bradykinin-induced albumin output and submucosal gland secretion in the ferret trachea in vivo.

In the ferret liquid-filled trachea in vivo, intraluminal bradykinin (BK, 3-300 microM) produced concentration-dependent increases in the output of lysozyme from submucosal gland serous cells and albumin movement into the lumen. Baseline outputs of albumin and lysozyme were not altered significantly by intraluminal indomethacin (10 microM) or thiorphan (10 microM). However, intraluminal indomethacin completely blocked the BK-induced increase in albumin output. Intraluminal thiorphan (10 microM) did not significantly potentiate BK-induced albumin output, although mean output was higher. Neither indomethacin nor thiorphan significantly altered BK-induced lysozyme output, although mean output was reduced in the presence of indomethacin. Thus BK increases albumin output and may increase lysozyme output via the action of cyclooxygenase products. Inhibition of neutral endopeptidase activity may enhance the action of BK on albumin output.

Albumins↗
PubMed1993

Expression of monocyte chemoattractant protein 1 (MCP-1) in adult periodontal disease: increased monocyte chemotactic activity in crevicular fluids and induction of MCP-1 expression in gingival tissues.

The present study shows that monocyte chemotactic activity in crevicular fluids increases with severity of the disease and that a monocyte chemoattractant, monocyte chemoattractant protein 1 (MCP-1), is expressed as the predominant cytokine of gingival tissues and their fibroblasts treated with Porphyromonas (Bacteroides) gingivalis lipopolysaccharide (P-LPS). High monocyte chemotactic activity in the crevicular fluids was neutralized significantly by antiserum specific for the JE/MCP-1 protein. Marked expression of the MCP-1 gene was observed in the gingival tissues of all adult periodontal patients tested, but not in those of healthy subjects. Monocyte chemotactic activity was observed in culture supernatants of human normal gingival tissues treated with P-LPS, and the chemotactic activity increased in a dose-related manner. Expression of MCP-1 in P-LPS-treated human gingival fibroblasts was further examined. P-LPS induced the MCP-1 gene expression in a dose- and treatment time-dependent manner. The MCP-1 gene product in the culture supernatant was detected as two forms with molecular masses of 11,000 and 15,000 Da by immunoprecipitation with the specific antiserum. The MCP-1 gene expression was induced in the fibroblasts treated with interleukin-1 beta and tumor necrosis factor alpha, but not with interleukin-6. These results suggest that gingival fibroblasts can participate in monocyte recruitment in gingival tissues of adult periodontal patients via the MCP-1 gene product and that MCP-1 plays an important role in the inflammatory reaction in the disease.

Adult↗
PubMed1993

Laparoscopic cholecystectomy: the Japanese experience.

We investigated the current status of laparoscopic cholecystectomy in Japan. A retrospective survey of laparoscopic cholecystectomy was performed involving 1989 patients from eight Japanese institutions. The preoperative work-up and the operative technique were largely identical to those in the United States. Conversion to open cholecystectomy was required in 54 patients (2.7%) because of unexpected intraoperative findings such as inflammation and adhesions in 40 patients (2.0%) and intraoperative complications in 14 patients (0.7%). There were no deaths, and postoperative complications occurred in 34 of 1935 patients (1.75%) in whom laparoscopic cholecystectomy was completed. Only 10 patients (0.51%) had serious complications (hemorrhage and bile duct injury, for example) that required laparotomy. The incidence of bile duct injury was 11 of 1989 (0.55%). We conclude that the adoption of laparoscopic cholecystectomy in Japan has been highly successful.

Cholecystectomy, Laparoscopic↗
PubMed1993

Effects of beraprost sodium, a stable analogue of prostacyclin, on hyperplasia, hypertrophy and glycosaminoglycan synthesis of rat aortic smooth muscle cells.

The effects of beraprost sodium, a stable analogue of prostacyclin, on the syntheses of DNA, protein and glycosaminoglycans (GAG) of cultured vascular smooth muscle cells (SMC) were studied. SMC were isolated from the thoracic aorta of male Wistar rats. The syntheses of DNA, protein and GAG of SMC were determined by incorporations of [3H]thymidine, [3H]leucine and [35S]sulfuric acid, respectively. Insulin at a concentration of 10(-6) M stimulated DNA synthesis 4 fold compared to control. Beraprost sodium suppressed the insulin-stimulated DNA synthesis dose-dependently at concentrations greater than 10(-7) M and suppressed it by 68% at 10(-5) M. Platelet derived growth factor (PDGF) at a concentration of 20 ng/ml stimulated DNA synthesis 6 fold compared to control. Beraprost sodium suppressed the PDGF-stimulated DNA synthesis dose-dependently at concentrations greater than 10(-7) M and suppressed it by 51% at 10(-5) M. Beraprost sodium suppressed GAG synthesis dose-dependently at concentrations greater than 10(-7) M and suppressed it by 49% at 10(-5) M. However, beraprost sodium at concentrations up to 10(-5) M did not affect protein synthesis. These results indicate that beraprost sodium suppressed the proliferation and GAG synthesis of SMC but did not affect hypertrophy. Beraprost sodium may be a potent antiarteriosclerotic agent through suppression of hyperplasia of SMC and modification of matrix protein.

Animals↗
PubMed1993

[Effects of ascorbic acid on trace element metabolism in the choroid-retina of streptozotocin-induced diabetic guinea pigs].

In order to investigate the effect of ascorbic acid on trace element metabolism in the choroid-retina, experimental diabetes mellitus was induced in Hartley guinea pigs with intraperitoneal injection of streptozotocin. After 4 weeks, ascorbic acid-deficient feed was given for 3 weeks. Trace elements of the choroid-retina were measured with inductively-coupled plasma emission spectrometry. The activity of superoxide dismutase and lipid peroxide content also were measured. The results indicated that zinc and magnesium increased in diabetes mellitus. However, with ascorbic acid deficiency in diabetes mellitus, zinc and magnesium significantly decreased. On the other hand, the activity of superoxide dismutase showed no change between either condition and lipid peroxide content decreased under ascorbic acid deficiency in diabetes mellitus. These findings suggested that ascorbic acid played an important role in chorioretinal damage of diabetes mellitus. However, it was also suggested that lipid peroxide has little influence on the choroid-retina under these conditions.

Animals↗
PubMed1993

[Clinical evaluation of postoperative adjuvant arterial infusion chemotherapy in resected hepatoma patients].

Eighty surgically treated patients with advanced hepatocellular carcinoma (HCC) were divided into two groups. In group I, twenty patients whose mean diameter of tumors was 56 mm, prophylactically underwent hepatic arterial infusion chemotherapy after liver resection. Chemotherapeutic agents (5-FU, ADM, MMC, CDDP, Lipiodol) were administered 4 times a year via Infuse A port. The remaining 60 patients, whose mean diameter of tumors was 57 mm, served as the control without prophylactic infusion (group II). The 2-year cumulative survival rate was higher in the prophylactic group (71%) than the control (48%, p = 0.040). The two-year disease-free survival rate was improved in group I (38%) compared with that in group II (27%, p = 0.021). Intrahepatic multiple recurrence within 1 year after surgery was recognized in four out of 18 patients of group I (22%) and in thirty-three out of 60 patients of group II (55%, p = 0.029). In group I, two cases who died of hepatic failure with no recurrence, had lower functional reverse and a larger amount of Lipiodol than the remaining 18 patients. Adjuvant arterial infusion chemotherapy can thus be be efficacious in alleviating hepatoma recurrence after liver resection. For patients with poor liver function, a smaller volume of chemotherapeutic agents might be feasible.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Sclerotherapy vs. esophageal transection vs. distal splenorenal shunt for the clinical management of esophageal varices in patients with child class A and B liver function: a prospective randomized trial.

Ninety-six patients with good liver function (Child class A or B) and esophageal varices were randomly assigned to one of three groups given different treatments: endoscopic injection sclerotherapy (n = 32), esophageal transection (n = 32) or distal splenorenal shunt (n = 32). Five patients (5.2%) had to be excluded from this study because severe chronic pancreatitis made separation of the distal splenic vein from the pancreatic bed difficult. Esophageal transection was performed for these patients. No deaths occurred during the 30 days of treatment. The 5-yr cumulative bleeding rates were 0%, 5.9% and 12.9% in the endoscopic injection sclerotherapy, esophageal transection and distal splenorenal shunt groups, respectively (no statistical significance). In no case in the three groups did death occur because of variceal bleeding. Sixteen patients died, mainly because of underlying liver disease; four were in the endoscopic injection sclerotherapy group, five were in the esophageal transection group and seven were in the distal splenorenal shunt group. No statistically significant difference in survival rate among the three groups was found. These results show that endoscopic injection sclerotherapy is a satisfactory alternative to esophageal transection or distal splenorenal shunt for the clinical management of patients with esophageal varices.

Esophageal and Gastric Varices↗
PubMed1992

Endoscopic injection sclerotherapy for 1,000 patients with esophageal varices: a nine-year prospective study.

We report here the results of endoscopic injection sclerotherapy performed in 1,000 consecutively treated Japanese patients with esophageal varices. This prospective study covered the period from 1982 to 1990. Variceal bleeding was controlled in 215 (97.7%) of 220 patients. Esophageal varices were completely eradicated in 778 patients (77.8%); the mean number of sessions was 4.2. In only 3 of the 778 patients did esophageal varices of the same size recur. Small, dilated, venous vessels that required additional sclerotherapy in follow-up endoscopy at 3-mo intervals appeared in 171 (22.2%) of 778 patients. The cumulative nonbleeding rate at 5 yr was 94.5% in patients in whom the varices had been eradicated. Deaths caused by upper gastrointestinal bleeding accounted for 2.6% of cases, whereas the rates of liver failure and hepatoma were 4.6% and 47.3%, respectively. The 5-yr cumulative survival rate was 54.1% in patients without concomitant hepatoma; it was 12.0% in patients with hepatomas. Multivariate analysis showed that hepatoma, Child classification, indication (acute, elective or prophylactic) and eradication were independent factors that significantly influenced survival time. This study clearly shows that close follow-up with endoscopy and complete eradication lead to significant reduction in bleeding from esophageal varices and reduction of mortality related to this bleeding.

Endoscopy↗
PubMed1992

An assay system utilizing devitalized bone for assessment of differentiation of osteoclast progenitors.

The present study provides a novel assay system to examine the differentiation of osteoclast progenitors on devitalized bone slices. We used the population of bone cells liberated enzymatically from 14-day-old mouse embryonal calvariae as a source of osteoclast progenitors. The analysis of differentiation of osteoclast progenitors into preosteoclasts and mature osteoclasts was assessed in terms of the formation of TRAP-positive cells and pits or resorption lacunae, respectively, on devitalized bone slices. Osteoclasts having bone-resorbing activity appeared when the calvarial cell population was cultured in the presence of 1 alpha,25-(OH)2D3 on devitalized bone slices. The resorbing activity increased in a 1 alpha,25-(OH)2D3 dose-related manner. However, calcitonin, a potent inhibitor of differentiation and activation of osteoclast lineage cells, reduced the area of the resorption lacunae in a dose-dependent fashion. The bone-resorbing cells on the bone slices expressed an obvious ruffled border and clear zone, structures specific to mature osteoclasts. These results suggest that osteoclast progenitors in the mouse calvarial population examined differentiated into mature osteoclasts in the presence of 1 alpha,25-(OH)2D3 on devitalized bone slices. Further, using this assay system we assessed the effect of some other osteotropic factors on the differentiation of osteoclast progenitors to mature osteoclasts. IL-1, IL-6, and PTH increased the formation of TRAP-positive cells and pits and the area of resorption lacunae in a dose-dependent fashion. However, prostaglandin E2 was unable to induce the formation of resorption lacunae, although a significant appearance of TRAP-positive cells was observed at a concentration of 200 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1992

Effect of ipriflavone on bone mineral density and calcium-related factors in elderly females.

The effects of ipriflavone (7-isopropoxy-3-phenyl-4H-1-benzopyran-4-one) on bone mineral density (BMD) of the 3rd lumbar vertebra and on calcium (Ca)-related factors, including serum calcitonin (CT) levels before and after rapid calcium infusion (4 mg/kg for 5 minutes), were studied in 11 elderly female subjects (80 +/- 2 years of age, mean +/- SE). Ipriflavone (IP) administration (600 mg/day, 7 months) resulted in inhibition of BMD loss in 7 patients (responders, mean change of BMD value 2.2 +/- 2.3%), whereas 4 patients showed a loss of BMD (nonresponders, mean change of BMD value -13.1 +/- 2.6%) compared with pretreatment values. The responder group showed a significant increase in mean pretreatment serum CT levels (from 20 +/- 2 pg/ml to 42 +/- 7 pg/ml, P < 0.05) after treatment with IP, and a significant decrease in the mean basal serum level of corrected Ca (from 9.6 +/- 0.2 mg/dl to 8.7 +/- 0.1 mg/dl, P < 0.01) after treatment with IP; nonresponders did not show these changes. For responders, both the percentage of change and the maximal value of serum CT in response to Ca infusion were maintained at rather high levels, both before and after IP treatment; nonresponders showed almost no response to a stimulation test for CT. These findings suggest that IP inhibits bone loss in elderly female subjects possibly through the mechanism of increasing CT secretion.

Aged↗