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Biomedical subjects

M Sakamoto

Publications and source records attributed to M Sakamoto.

At least 487 records · Page 27Linked to original sources
PubMed1993

Characterization of tumor necrosis factor alpha-induced alteration of glycosaminoglycans in cultured cells: comparison among vascular smooth-muscle cells, vascular endothelial cells, Chang liver cells and LLC-PK1 cells.

We investigated the alteration of glycosaminoglycans (GAGs) induced by recombinant human tumor necrosis factor alpha (rhTNF alpha) using confluent cultures of bovine aortic smooth-muscle cells, bovine aortic endothelial cells, Chang liver cells and porcine kidney LLC-PK1 cells. It was found that the incorporation of both [35S]sulfate and [3H]glucosamine into GAGs in the trypsinate fraction of the cell layer was significantly decreased by rhTNF alpha in vascular smooth-muscle cells and vascular endothelial cells; the incorporation of [35S]sulfate was increased but that of [3H]glucosamine was unchanged in Chang liver cells; the incorporation of both [35S]sulfate and [3H]glucosamine was increased by rhTNF alpha in LLC-PK1 cells. In the conditioned medium, the incorporation of both [35S]sulfate and [3H]glucosamine was not greatly changed by rhTNF alpha in all tested cell types. Characterization of GAGs revealed that each cell type uniquely altered its GAGs after rhTNF alpha treatment; the cytokine-induced alteration of each GAG component was not necessarily the same among different cell types. It was therefore concluded that rhTNF alpha-induced alteration of GAGs is dependent upon cell type.

Animals↗
PubMed1993

[Difference by sex and age of mercury concentration in red blood cells].

The mercury concentration in red blood cells (RBCs) is one of the most useful indicators for people exposed to methylmercury. Sex- and age-related differences in mercury concentrations in red blood cells were studied by considering fish consumption in 1,253 adults (511 males and 742 females) participating in a mass health examination conducted in a town of Kumamoto Prefecture in 1989. The results were as follows: 1. The mercury concentrations in RBCs showed lognormal distributions for both sexes with a higher mode in males than in females. The geometric mean of the mercury concentrations in the RBCs was 28.5 ng/g (ranging from 5.6 to 71.0 ng/g) for males and 20.4 ng/g (ranging from 3.7 to 70.4 ng/g) for females and was significantly higher in males than in females. The mercury concentration in RBCs decreased with aging for both sexes. 2. The mercury concentrations in RBCs significantly increased with the amount of fish consumption for both sexes. The mercury concentrations in RBCs were significantly higher in drinkers than in non-drinkers for males and the concentrations increased significantly with body weight for females. 3. The mercury concentrations in RBCs were higher in males than in females and decreased with aging for both sexes under conditions of a constant level of fish consumption. 4. In couples who consumed same amount of fish, the mercury concentrations in RBCs were significantly higher in husbands than in wives. These results suggest that the mercury concentrations in RBCs are higher in males than in females and decreases with aging under a constant level of fish consumption.

Adult↗
PubMed1993

Two cases of protruding atherosclerotic plaque with mobile projections in the aortic arch.

We recently studied two patients with cerebral embolism, in whom transesophageal echocardiography revealed protruding atherosclerotic plaques with freely mobile projections in the aortic arch. Ultrasonic imaging showed that the carotid artery was normal, and transthoracic and transesophageal echocardiography did not reveal a cardiac embolic source in either case. In one patient, we observed that an atherosclerotic plaque became ulcerated and developed mobile projections over the course of a year. More consideration should be given to the thoracic aorta as a source of embolism in patients with unexplained stroke.

Aged↗
PubMed1993

Response of early-stage hepatocellular carcinoma and borderline lesions to therapeutic arterial embolization.

OBJECTIVE: In Japan, borderline lesions and early-stage hepatocellular carcinoma (HCC) are now histopathologically divided into two subgroups; one includes adenomatous hyperplasia and atypical adenomatous hyperplasia, and the other includes early HCC and early advanced HCC. In order to evaluate the efficacy of transcatheter arterial embolization for treating such lesions, histopathologic studies were done after embolization and resection in 27 patients. MATERIALS AND METHODS: The lesions consisted of two adenomatous hyperplasias, one atypical adenomatous hyperplasia, 22 early HCCs, and 13 early advanced HCCs. All patients had chronic liver diseases in nontumorous parenchyma in addition to HCC. For transcatheter arterial embolization, one of the following embolizing materials was used: iodized oil (Lipiodol) alone (n = 4), an emulsion of doxorubicin in Lipiodol (n = 8), and the same emulsion followed by gelatin sponge particles (n = 15). RESULTS: The frequencies of tumor stain on the angiogram and retention of Lipiodol within the tumor were 84% and 94% in overt HCC, 23% and 69% in early advanced HCC, and 9% and 9% in early HCC, respectively. The average size of overt HCC was significantly (p < .01) larger than that of early advanced HCC and early HCC. The amount of necrosis induced by embolization relative to the size of the mass was 56% on average in overt HCCs, 14% in early advanced HCCs, and 0% in early HCCs, atypical adenomatous hyperplasias, and adenomatous hyperplasias. Significant differences (p < .01) in mean necrosis rate were seen between overt HCCs and early advanced HCCs, between early advanced HCCs and early HCCs, and between overt HCCs and early HCCs. The frequency of Lipiodol retention correlated with mean necrosis rate for tumor. With reference to therapeutic techniques, only for the overt HCCs was a significant difference (p < .01) in the mean necrosis rate found between the group that received the emulsion of doxorubicin in Lipiodol and the group that received the emulsion and then particles of gelatin. CONCLUSION: This study suggests that transcatheter arterial embolization has limited efficacy for treating early-stage HCC and borderline lesions compared with its efficacy for treating overt HCC.

Aged↗
PubMed1993

Trial of insulinlike growth factor I therapy for patients with extreme insulin resistance syndromes.

Extreme insulin resistance occurs in patients with primary defects in insulin action at the receptor or postreceptor levels. The condition commonly is associated with acanthosis nigricans and ovarian masculinization. Despite a marked increase in insulin secretion, some patients develop frank diabetes mellitus that does not respond adequately to insulin therapy. Insulinlike growth factor I exerts metabolic effects similar to those of insulin. This study assessed the potential effectiveness of IGF-I as a blood glucose lowering agent in patients with extreme insulin resistance syndromes, including type A insulin resistance, congenital generalized lipodystrophy, and leprechaunism. Among the 11 patients studied, some exhibited mutated insulin receptors, whereas others were suspected to have defects in postreceptor sites. In each patient, plasma glucose levels decreased in response to subcutaneous injections of recombinant human IGF-I (0.1-0.3 mg/kg body wt). The degree of the decrease was roughly comparable with that observed in normal individuals. IGF-I also reduced plasma insulin concentrations. A long-term trial of IGF-I (up to 16 mo) showed that IGF-I (0.1-0.4 mg/kg body wt twice daily) is effective in lowering both fasting and postprandial plasma glucose concentrations with decreases in both fructosamine and HbA1c values. Improvement of acanthosis nigricans was observed in some of the patients. These results suggest that recombinant human IGF-I could be used clinically as a hypoglycemic agent in diabetic patients with extreme insulin resistance in whom insulin treatment is ineffective.

Acanthosis Nigricans↗
PubMed1993

Experience with a new intraurethral stent for high-risk patients with benign prostatic hypertrophy.

Eight patients with benign prostatic hypertrophy (BPH), considered as a high risk for an operation because of severe accompanying disease, were treated with a self-retaining intraurethral catheter set. Two patients were judged unfit for operation (one because of severe cardiac failure, the other because of severe respiratory failure) and 1 patient rejected an operation. The BPH surgery was postponed in the others because of recent operations for such diseases as gastric cancer or because of severe gastric ulcer. All patients voided freely after stent placement and were continent. The device was left in place for 1 to 16 weeks. The chief complaint was frequency of voiding, with intervals of 1 to 2 hours. Some micturition discomforts such as urgency were recognized in 2 patients, but disappeared within 1 to 2 days. Pyuria observed before treatment disappeared in all but 1 patient. Average residual urine volume calculated on ultrasonograms was 54 ml. Stone formation was demonstrated in 1 patient 9 weeks after placement. We concluded that the intraurethral stent is an effective device for high-risk patients with BPH. However, a longer follow-up study will be needed to exclude late side effects.

Aged↗
PubMed1993

Phenotype changes in tumor vessels associated with the progression of hepatocellular carcinoma.

Human hepatocellular carcinoma (HCC) is characterized by hypervascularity and tumor staining in angiograms, and tumor angiogenesis is considered indispensable for tumor growth. HCC is also characterized by an obvious multistage process of tumor progression. To find out in which stage of human hepatocarcinogenesis angiogenesis occurs, we have carried out a pathological study, of the phenotypic changes in tumor vessels taken from surgically resected liver tumors showing each step of the progression. Eleven early advanced HCCs (advanced HCC component in early HCC nodule, eAd HCC), seven early HCCs (eHCC) and six adenomatous hyperplasias (AH), the non-tumorous liver surrounding each and five normal livers were studied by lectin histochemistry and immunohistochemistry. The sinusoidal endothelial cells from the non-tumorous liver were shown to be negative for UEA-I (Ulex europaeus I), but the endothelial cells from the sinusoidal tumor vessels in advanced HCC components were strongly positive. In AH and eHCC, half the tumors were negative and the other half focally positive. In the early HCC lesion of eAdHCC, the rate of positivity for UEA-I was a little higher than in AH and eHCC but lower than in advanced HCC lesions in eAdHCC. Immunohistochemically, laminin was not detected in the sinusoids in the non-tumorous liver or in the sinusoidal tumor vessels in AH and eHCC. In eAdHCC, however, two early HCC lesions and four advanced HCC lesions were positive. An immunohistochemical examination for muscle actin revealed an increase in arterial tumor vessels in six advanced HCC lesions and one early HCC lesion of eAdHCC. The results indicate the emergence of UEA-I-positive sinusoidal tumor vessels to be most pronounced during the progression from eHCC to advanced HCC, and laminin-positive sinusoidal tumor vessels or actin-positive arterial tumor vessels to emerge mainly in advanced HCC.

Actins↗
PubMed1993

[A case of metastatic urinary bladder tumor from colon carcinoma].

A 62-year-old female patient underwent an operation for a brain tumor. The pathological diagnosis of the resected specimen was metastatic adenocarcinoma with signet-ring cells. The primary lesion was found in the ascending colon. In addition, a non-papillary and pedunculated tumor was found on the right wall of the bladder on cystoscopy. Biopsy of the bladder tumor showed adenocarcinoma with signet-ring cells, which was the same as the histologies of the colon and the brain tumors. Under the diagnosis of metastatic bladder tumor, transurethral resection of the tumor was performed. This is the first case of metastatic bladder carcinoma from the colon reported in Japan.

Brain Neoplasms↗
PubMed1993

[Studies of emergency cardiopulmonary bypass (ECPB) for cardiopulmonary-cerebral resuscitation--(3). Neurological outcome and pathological changes of the brain].

Neurological outcome and pathological changes of the brain were studied in 5 female mongrel dogs, which were subjected to normothermic ventricular fibrillation (Vf) cardiac arrest of 15 min and resuscitated by using cardiopulmonary bypass through the femoral artery and veins (F-F bypass). Spontaneous circulation was restored by one or two defibrillating countershocks in all 5 dogs 5.2 +/- 1.1 (mean +/- SD) min after initiation of the F-F bypass. The F-F partial bypass was continued for 164 +/- 30 min under mild hypothermia. After weaning from the bypass, intensive care including controlled ventilation was carried out for the subsequent 6 to 36 h. Intermittent slow waves appeared on the electroencephalogram 62.8 +/- 11.6 min after initiation of the F-F bypass resuscitation and continuous waves at 145.6 +/- 27.5 min. Soon after extubation, the animals barked, moved the forelegs and could drink water. Neurological deficit scores (normal: 0, brain death: 500) improved to become below 100 except in 1 dog. However, macroscopic examination of the brain in 2 dogs with prominent recovery disclosed atrophy of the central gyrus and microscopic examination revealed typical ischemic injuries of the vulnerable neurons at the cerebellum, hippocampus and cerebral cortex in the frontal lobe.

Animals↗
PubMed1993

Transitional cell carcinoma of the upper urinary tract: analysis of morphology and distribution for surgical management.

Two series of transitional cell carcinomas (TCC), one including 49 renal pelvic and/or ureteral cancers and the other 29 bladder cancers with concomitant ureteral involvement, were reviewed to establish the criteria for nephron-sparing surgery and for selecting the most appropriate surgical intervention for TCCs at the ureterovesical junction. The following categorization of tumors was made possible by histological mappings of step-sectioned surgical specimens from various surgical modes: 1) low grade papillary superficial tumor, 2) high grade papillary or non-papillary tumor with adjacent or skipped carcinoma in situ (CIS), 3) high grade non-papillary invasive tumor without CIS, 4) high grade papillary superficial tumor without CIS. We can, by comparing postoperative clinical courses, select the mode of surgery in the following manner: 1) nephron-sparing surgery could be indicated in cases of low grade papillary tumor so far as a complete resection is possible; 2) in a case of high grade papillary or non-papillary tumor with adjacent or skipped CIS, extended resection of the urinary tract is required; 3) in a case of high grade non-papillary tumor without CIS, complete en bloc resection of the tumor site, including surrounding organs, will be necessary. The possibility of organ-sparing surgery for early stage cancer without CIS at the ureterovesical junction has been suggested. Preoperative consideration of the above classifications for conservative surgery is also discussed.

Adult↗
PubMed1993

A ureteral small cell carcinoma mixed with malignant mesodermal and ectodermal elements: a clinicopathological, morphological and immunohistochemical study.

A 60-year-old male with a small cell carcinoma of the right lower ureter is presented. The tumor mainly comprised a small cell carcinoma but also included a full variety of histological types such as transitional cell carcinoma, squamous cell carcinoma, adenocarcinoma, leiomyosarcoma and chondrosarcoma. Immunohistochemical staining was positive for neuron specific enolase and cluster 1 small cell lung cancer antigen/N-CAM in the small cell carcinoma and S-100 in the chondrosarcoma component. The patient underwent a right nephroureterectomy, and received prophylactic radiation of the pelvic and para-aortic lymph node regions and cisplatin and etoposide combination chemotherapy. Eight months after the chemotherapy, a transitional cell carcinoma was found in the bladder neck, and a cystectomy with urethrectomy performed. To our knowledge, this is the second report of a small cell carcinoma originating from the ureter.

Biomarkers↗
PubMed1993

[Clinical studies on methicillin-resistant Staphylococcus aureus (MRSA) infections].

We experienced 20 cases of methicillin-resistant Staphylococcus aureus (MRSA) infection from April 1991 to September 1992. Of them, 9 showed substantial morbidity and their clinical courses are herein reported. The clinical presentations of these cases were wound infection and enterocolitis. Although in 8 cases MRSA was eradicated in 14 to 160 days by effective antibiotics administration, one had a fatal outcome. All strains isolated showed similar drug-sensitivity pattern suggesting hospital infection. Sensitivity to vancomycin and arbekacin, however, remained high and these drugs were effective clinically. It should be stressed that treatment strategy of MRSA infection should consist of isolation of patients with MRSA from other patients, use of disposable equipment and products, and serious and continuing concerns of medical personal on communicability of MRSA.

Aged↗
PubMed1993

[Strangulation of the penis by a metallic ring].

An 81-year-old male patient visited our hospital on November 13, 1992 for the treatment of penile edema that had been caused by a metallic ring which he placed for fun 4 days prior to the visit. He had placed the metallic ring on the base of the penis and subsequent penile edema made it impossible to remove the ring. He had no problem with urination. The ring was successfully removed with a metal-cutting tool. But 3 days later, infected penile ulceration occurred at the base of the penis and the necrotic tissue was resected. It took 25 days for the wound to heal. It is stressed that penile strangulation is a serious injury and prompt removal is necessary.

Aged↗
PubMed1993

Bactericidal effects of povidone-iodine solution to oral pathogenic bacteria in vitro.

Seven species of periodontal pathogenic bacteria (Bacteroides, gingivalis, Bacteroides intermedius, Bacteroides melaninogenicus, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Capnocytophaga spp., Eikenella corrodens) and two control species (Streptococcus intermedius, Pseudomonas aeruginosa) were selected in order to study the bactericidal effects of 10% povidone-iodine (PVP-I) aqueous solution in vitro. The PVP-I solution was diluted to 10, 20, 50, 100, 200, 400, 800, 1600, 3200, 6400 and 12800 x and contact times were 15, 30 and 60 seconds. The strongest bactericidal effects on the seven periodontal pathogenic bacteria and two control bacteria were seen at a dilution of 400 x and a contact time of 15 seconds. Based on these findings, we advocate a 0.25% solution of 10% aqueous PVP-I for oral mucosa and periodontal pocket irrigation.

Aggregatibacter actinomycetemcomitans↗
PubMed1993

[An autopsy case developing both marked stenosis of the coronary artery and dilated phase of hypertrophic cardiomyopathy].

An autopsy case involving the dilated phase of hypertrophic cardiomyopathy (HCM) is reported. This case was also complicated with a lesion similar to fibromuscular dysplasia of the coronary artery. A 37 year-old male died of cardiac insufficiency and an autopsy was performed. Macroscopically, both atriums and ventricles were dilated and the walls of both ventricles were markedly thickened. Also, the coronary artery was almost completely obstructed. Histological examination revealed bizarre myocardial hyperplasia with disorganization and marked fibrosis of the myocardium. The coronary artery showed intimal fibrous thickening with increase in elastic fibers and smooth muscle cells. There were similar lesions in other arteries examined; the renal arteries, external iliac arteries, pulmonary arteries and aorta. We think that this lesion of the coronary artery plays an important part in the progression from hypertrophic cardiomyopathy to dilated cardiomyopathy.

Adult↗
PubMed1993

Pathology and DNA cytophotometry of small hepatocellular carcinoma with a nodule-in-nodule appearance--evidence for stepwise progression of hepatocellular carcinoma.

Among 92 surgically resected human hepatocellular carcinomas (HCCs) < or = 3 cm in diameter, 23 tumors (25%) grossly showed a nodule-in-nodule appearance indicating stepwise progression of HCC. The central nodules showed destructive growth of HCC, which was less differentiated than the surrounding area histologically, while the surrounding area showed growth of very-well-differentiated HCC with no, or only minimal, destruction of the underlying liver structures. Previously, we proposed the term "early HCC" for HCCs without definite destructive growth, and the nodule-in-nodule lesions described here are considered to be in the transitional stage from early HCC to advanced HCC, and are therefore named early advanced HCC (eAd HCC). DNA cytophotometry was performed in 12 cases of eAd HCC, in which the early HCC component, advanced HCC component and non-tumorous liver tissue showing chronic hepatitis or cirrhosis were analyzed separately. The early HCC component showed a diploid pattern in eight of the 12 cases. The advanced HCC component showed an aneuploid peak in seven cases, and in three of these the peak was detected only in the advanced HCC component and not in the early HCC component. The mean nuclear DNA content was significantly increased from non-tumorous liver to the early HCC component and from the early HCC component to the advanced HCC component. Polyploid cells containing more than 4.8C DNA were exceptional in non-tumorous liver, but were detectable in the early HCC component and increased in number in the advanced HCC component. These findings suggest that DNA instability may have an important role to play in the subclonal progression of human HCC.

Adult↗
PubMed1992

Possible mechanism for zinc protection against cadmium cytotoxicity in cultured vascular endothelial cells.

We investigated the effect of zinc on cadmium cytotoxicity in vascular endothelial cells in a culture system. The cytotoxicity was evaluated by [3H]adenine release assay. Cadmium at 2 microM concentration and above significantly increased the [3H]adenine release, but zinc at 80 microM and below did not induce such a response after a 24-h incubation. Metallothionein was induced by cadmium at 0.1 microM and above but not by zinc at 300 microM and below; however, zinc at 10 microM and above significantly decreased cadmium-(2 and 5 microM) induced cytotoxicity. Zinc protection against cadmium cytotoxicity was also observed in the presence of 1 microM cycloheximide. Zinc caused significantly less accumulation of cadmium in the cell layer accompanied with a significant accumulation of zinc. The distribution (%) of cadmium in the particulate fraction of the cells was significantly decreased by zinc. In contrast, cadmium in the cytosol fraction was increased in the cells treated with both cadmium and zinc. Gel filtration chromatography of the cytosol showed that cadmium was capable of being bound to high-molecular-weight proteins and metallothionein. The metallothionein-bound cadmium was not increased by zinc; however, the relative distribution of cadmium in the high-molecular-weight fraction in the cytosol was decreased in cadmium plus zinc-treated cells. From these results, it was suggested that the mechanism by which zinc protects endothelial cells from cadmium cytotoxicity was decreased accumulation of cadmium in the particulate fraction and in the high-molecular-weight fraction in the cytosol of the cells. This alteration is postulated to be caused by both zinc-induced decrease in the intracellular cadmium accumulation and the sequestration of cadmium by cadmium-induced metallothionein.

Adenine↗