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Biomedical subjects

W Sakamoto

Publications and source records attributed to W Sakamoto.

At least 55 records · Page 3Linked to original sources
PubMed1994

[A case of testicular tumor with a small tumor focus in the testis].

The initial symptom of a testicular tumor is painless enlargement of the testis in most cases, but in some cases can manifest itself with metastatic lesions associated with a small focus. On the other hand, a occult testicular tumor accompanied by a minimal lesion in the testis, may be included in the category of extra gonadal germ-cell tumors. We have seen a 41-year-old male with a chief complaint of swelling of a cervical lymph node, who was found to have a tumor in the testis of normal size. A CT scan revealed a tumor in the retroperitoneal space. The serum levels of HCG and AFP were markedly elevated. Biopsy of the cervical lymph node established a diagnosis of embryonal cell carcinoma. The left testis, free from a palpable mass but tender, was excised. A gonadal cell tumor approximately 7 mm in size was just below the epididymis. A stage III-a testicular tumor was diagnosed in the patient. Three courses of VAB-6 yielded partial relief in the patient. We concluded that the testis should be carefully examined with echogram whenever a extra gonadal germ-cell tumor is suspected, since a tiny lesion can exist in the testis concomitantly in some cases.

Adult↗
PubMed1994

Bradykinin and Met-T-kinin-Leu stimulated PGE2 production by rat macrophage and fibroblast.

T-kininogen degradation and kinin release were observed in rat macrophages cultured under acidic conditions. Bradykinin and Met-T-kinin-Leu (a kinin precursor) stimulated PGE2 production by macrophages and fibroblasts but had no effect on O2- production. PGE2 production by macrophages stimulated with 10 microM bradykinin increased by approximately 148% compared to non-stimulated macrophages (0.47 +/- 0.13 vs 0.31 +/- 0.16 ng 10(6) cells-1 30 min-1), and increased by 161% in stimulated as opposed to non-stimulated fibroblasts (0.50 +/- 0.07 vs 0.31 +/- 0.05 ng 10(5) cells-1 30 min-1). No O2- production was detectable in fibroblasts despite stimulation with PMA, A23187, bradykinin, and Met-T-kinin-Leu. O2- production by macrophages was 4.2 +/- 0.3 and 3.0 +/- 0.2 nmol 10(6) cells-1 min-1 after stimulation with PMA and A23187, respectively, but no O2- production was observed after stimulation with bradykinin or Met-T-kinin-Leu. These data suggest that bradykinin and the kinin precursor are implicated in granulomatous tissue formation and wound healing through arachidonic acid and its metabolites but not through O2-.

Animals↗
PubMed1994

[Clinical studies of factors influencing acute tubular necrosis after kidney transplantation].

It is known that the earlier the graft begins functioning after cadaver kidney transplantation, the better the graft survival rate and function will be. In order to examine the possibility of shortening the period of acute tubular necrosis (AIN), we retrospectively studied the effect of several factors on the duration of postoperative hemodialysis. The subjects were 27 patients on whom a cadaver kidney transplantation was performed during a 6-year period from July 1, 1986. The mean duration of postoperative hemodialysis was 14.0 days in 26 out of the 27 patients. The remaining patient showed a primary non-functioning kidney. A significant correlation was observed between the anastomosis time and the duration of postoperative hemodialysis. No significant correlations were noted between the duration of postoperative hemodialysis and the age of the donor, renal function during the 24 hours preceding nephrectomy, or cold ischemic time. Moreover, no significant difference was observed in the duration of postoperative hemodialysis between patients using a roller pump for perfusion and patients who did not. The duration of postoperative hemodialysis was significantly shorter in patients using UW solution than in patients using Euro-Collins solution. Graft survival rate 6 months and one year after transplantation was 88.9% and 83.3%, respectively in the EC group, and 100% and 100%, respectively, in the UW group. It was concluded from these results that a short anastomosis time is essential in order to shorten the period of ATN after cadaver kidney transplantation, and that UW solution is effective in shortening the duration of postoperative hemodialysis and improving the graft survival rate thereafter.

Adenosine↗
PubMed1993

Effect of vitamin E on arachidonic acid-release in rat peritoneal macrophages.

We have previously reported on suppression of the PGE2 production in PMA- and calcium ionophore A23187-stimulated macrophages isolated from vitamin E-treated rats. To further study the mechanism, we examined the effect of vitamin E on phospholipase A2 activity in both intact macrophages and cell-free homogenates measuring the release of [14C]arachidonic acid. In macrophages from vitamin E-treated rats, arachidonic acid release in intact cells as stimulated with PMA and calcium ionophore A23187 was hardly detected. In the cell-free homogenates, increase in phospholipase A2 activity of cytosol and particulate fractions by PMA and A23187 was partially suppressed. In unstimulated macrophages, most of phospholipase A2 was recovered in the cytosol fraction. The partially purified cytosolic phospholipase A2 showed a molecular mass 95 kDa on TSK gel G3000SW gel-filtration and on Western blot analysis using anti-rabbit platelet phospholipase A2 monoclonal antibody RHY-5. The activity of cytosolic 95 kDa phospholipase A2 was not inhibited in vitro by vitamin E. From these results, it was suggested that vitamin E needs intact macrophages to suppress arachidonic acid release.

Animals↗
PubMed1993

In vivo analysis of Chlamydomonas chloroplast petD gene expression using stable transformation of beta-glucuronidase translational fusions.

We have used the Escherichia coli beta-glucuronidase (uidA) gene as a reporter gene to localize the promoter and analyze the function of the 5' untranslated region (UTR) of the Chlamydomonas chloroplast petD gene. Using particle bombardment, petD-uidA transcriptional and translational fusion genes were introduced into the chloroplast genome in the large inverted repeat flanking the atpB gene. In transformants carrying a petD-uidA transcriptional fusion, uidA mRNA accumulated but was not translated. However, in a translational fusion that included the entire petD 5' UTR, uidA mRNA accumulated and a high level of beta-glucuronidase activity was detected. When approximately 70% of the petD 5' UTR was deleted from the translational fusion, uidA mRNA accumulation and beta-glucuronidase activity decreased 4- to 6-fold and 8-fold, respectively. Run-on transcription assays demonstrated that all strains transcribe the uidA gene at equivalent rates. Our results show that sequences essential for translation reside in the petD 5' UTR and also that sequences within the 5' UTR directly or indirectly affect mRNA stability. The expression of beta-glucuronidase under the control of chloroplast transcriptional and translational signals will facilitate further studies of chloroplast gene regulatory mechanisms.

Animals↗
PubMed1993

[Clinical study of immunotherapy with interferon alpha and gamma in metastatic renal cell carcinoma].

A clinical study was conducted to evaluate the efficacy of combination therapy with interferon (IFN) alpha and gamma in 16 patients with advanced renal cell carcinoma whom we observed between August 1986 and June 1992. Eight patients had already had stage IV disease when they were seen first and five of them underwent nephrectomy. The other eight patients developed metastases after nephrectomy. The time to occurrence of the metastasis was 4-110 months. The dosage of the regimen was IFN alpha, 3 x 10(6) U, intramuscularly for 7 consecutive days at weeks 1, 3, 5 and 7 and IFN gamma, 6 x 10(6) JRU by intravenous drip on days 2, 4 and 6 of weeks 2, 4, 6 and 8. At and after week 9, the combined use of IFN alpha, 3 x 10(6) U, and IFN gamma, 1-6 x 10(6) JRU, was continued at least on a once-a-week basis as maintenance therapy as long as possible. The effect was evaluated as PR in 2 patients, MR in 2, NC in 3 and PD in 9. The response rate was 12.5% and the efficacy rate including MR was 25%. The time to onset of the effect was 8-24 weeks. Of the four patients showing MR or better responses, three had stage IV disease and one had metastatic disease after the operation. The duration of effect was 2-8 months. Side effects were fever, general malaise, anorexia, leukocytopenia and impaired liver function, and were noted frequently.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Effect of ciclosporin on cardiac output and regional blood flow in rats: ciclosporin-induced nephropathy and its prevention with calcium channel blocker.

The effect of ciclosporin (CS) on cardiac output (CO) and regional blood flow was studied using the microsphere method in heminephrectomized rats with and without renal arterial clamping prior to the administration of CS. The effect of a calcium (Ca) channel blocker, verapamil, was also examined on CS-induced nephropathy. CS at a dose of 40 mg/kg per day was given orally using a gastric tube for 7 days. Verapamil was given in the drinking water for 7 days. Significant increases in blood urea nitrogen (BUN) and serum creatinine (sCr) with a significant decrease in renal inulin clearance (CIn) were noted after 7 days of CS administration in both intact and ischemic-kidney groups, indicating the development of CS-induced nephropathy. The ischemic-kidney group showed a significantly severe nephropathy as compared with the intact-kidney group. As for change in CO and regional blood flow, CS caused a significant decrease in CO, renal blood flow (RBF) and brain blood flow, while hepatic arterial blood flow and muscular blood flow significantly increased. The renal outer cortical blood flow decreased markedly while the inner cortical blood flow remained unchanged. Although verapamil slightly but significantly decreased mean arterial blood pressure in CS-treated rats, CO and its distribution did not change. BUN and sCr were not significantly ameliorated in the intact-kidney group. However, in the ischemic-kidney group, verapamil caused a significant improvement in RBF, ameliorating CS-induced elevation of BUN and sCr, and a decrease in CIn.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[A case of muellerian duct cyst treated with minocycline hydrochloride sclerotherapy under ultrasound control].

We present a case of a muellerian duct cyst in a 55 year-old man. A cystic lesion was incidentally found between the prostate and the bladder on transabdominal ultrasound examination. Computerized tomography revealed a low density area homogeneous and round with a clear margin. Both urethrocystgram and vesiculogram demonstrated no cystic lesion. On diagnosis of muellerian duct cyst percutaneous needle aspiration was performed under ultrasound control. The aspirated fluid was yellow, clear and negative for cytology. Microscopically no spermatozoa were found in it. Minocycline (100 mg) was injected into the cyst. No recurrence has occurred since the operation. The literature of the cyst was briefly reviewed.

Cysts↗
PubMed1992

Action of a novel kinin precursor, Met-T-kinin-Leu, on prostaglandin I2 and blood pressure.

The novel kinin precursor, Met-T-kinin-Leu, stimulated the release of prostaglandin I2 from endothelial cells cultured using bovine carotid artery endothelial cells and minimum essential medium supplemented with 10% fetal calf serum. However, it failed to stimulate the release of prostaglandin I2 from the cells in the fetal calf serum-free medium conditions. To examine the discrepancy of the release of prostaglandin I2 from the cells by Met-T-kinin-Leu in the presence or absence of fetal calf serum, the products formed from Met-T-kinin-Leu by incubation of culture medium were analyzed by reverse-phase HPLC. Regarding the blood pressure reaction of Met-T-kinin-Leu, it showed from one fifth to one hundredth of that compared with bradykinin in blood pressure reactivity of each species, such as rats, rabbits and cats.

Animals↗
PubMed1992

Changes in polymorphonuclear neutrophil-elastase in pancreatitis.

In cases of acute and chronic pancreatitis, we measured the amount of polymorphonuclear neutrophil (PMN)-elastase. There was a significantly larger increase in PMN-elastase in patients with pancreatitis than normal adults. Especially, there was a particularly notable increase in amount of PMN-elastase in patients with severe pancreatitis. Furthermore, the peak of PMN-elastase increase throughout the course of the pancreatitis was seen to be 1-2 days after peak increase in pancreatic enzymes. In the experiment in which pancreatic juice and pig pancreatic kallikrein were added to granulocytes in vitro, we recognized a gradual release of PMN-elastase. From these data, we suggested that timely measurements of PMN-elastase are useful to marker of monitoring clinical changes in severe pancreatitis.

Acute Disease↗
PubMed1992

[A case of renal cyst associated with renal cell carcinoma--characteristics of intracystic fluid associated with renal cell carcinoma from Japanese reports].

The patient was a 56-year-old male. Renal cyst and intracystic mass were incidentally found in the right kidney by ultrasound sonography. Intracystic mass was enhanced. At operation, intracystic fluid was clear and yellow, and its cytology was negative. However, rapid histological examination of the intracystic mass showed malignancy. Accordingly, nephrectomy was performed. We then reviewed the characteristics of the intracystic fluid in renal cell carcinoma reported in Japan and found that 70% was bloody intracystic fluid and 30% showed positive cytology. These findings suggested that we should to be more careful when diagnosing renal cyst associated with renal cell carcinoma only by the examination of the intracystic fluid.

Body Fluids↗
PubMed1992

[A case of male pseudohermaphroditism with incomplete testicular feminization syndrome].

A 19-year-old female visited our hospital because of primary amenorrhea. She was genetically (46XY) male. Her breasts were poorly developed. She had no pubic or axillary hair. The phenotype was female, and the vagina had a short and closed end. Plasma testosterone (T) and 5-alpha dihydrotestosterone (DTH) were low. However, DHT was elevated by ex vivo T load. The testis, which was atropic, epididymis and vas deferens, which were well developed, were found and resected by operation. The amount of androgen receptors of the skin tissue of the external genitalia was normal. These findings suggested that male pseudohermaphroditism with incomplete testicular feminization syndrome may have been caused by androgen resistance syndrome due to the disorder of androgen receptor complex, genetic information or post receptor.

Adult↗
PubMed1991

Vitamin E inhibits PGE2 and O2- production in rat peritoneal macrophages.

In order to examine the possible role of vitamin E on the modulation of macrophages, we investigated the effect of vitamin E on O2- and PGE2 production in macrophages. The production of both PGE2 and O2- in rat peritoneal macrophages was dose-dependently stimulated by the addition of PMA and calcium ionophore A23187. However, the macrophages obtained after intraperitoneal injection of vitamin E for six successive days showed less PGE2 and O2- production when stimulated with PMA or A23187 as compared to those of control macrophages. O2- production in control macrophages stimulated with 139 nM PMA and 1 microM A23187 as 4.2 +/- 0.3 and 3.0 +/- 0.2 nmol/min per 10(6) cells, respectively. On the other hand, O2- production by the macrophages from vitamin E-treated rats was 1.5 +/- 0.4 nmol/min per 10(6) cells when stimulated with the PMA, and was not detectable when stimulated with A23187. As for the production of PGE2, control macrophages produced 2.59 +/- 0.70 ng/30 min per 10(6) cells when stimulated with PMA and 8.96 +/- 3.26 ng/30 min per 10(6) cells with the A23187, whereas PGE2 production by the macrophages from vitamin E-treated rats was reduced to 12-20% of the control. By analyzing alpha-tocopherol content and intracellular concentration of calcium ion [( Ca2+]i) in the macrophages isolated from control and vitamin E-treated rats, vitamin E treatment augmented alpha-tocopherol content (384.7 +/- 76.1 vs. 1.2 +/- 0.4 ng/10(6) cells) and decreased free [Ca2+]i when stimulated with A23187 (652 +/- 14 vs. 1201 +/- 223 nM).

Animals↗
PubMed1991

Inhibition of PGE2 production in macrophages from vitamin E-treated rats.

Rat peritoneal macrophages from vitamin E-treated rats (5 mg per rat for 6 successive days) contained 403.3 +/- 90.7 ng alpha-tocopherol/10(6) cells, whereas control macrophages contained 1.2 +/- 0.4 ng. PGE2 production in the macrophages from vitamin E-treated rats was significantly suppressed when stimulated with PMA and calcium ionophore A23187. The mechanism of vitamin E inhibition of PGE2 production in macrophages was investigated. The release of (14C)-arachidonic acid from pre-labeled macrophages and the conversion of (14C)-arachidonic acid to PGE2 by the homogenate of the cells were remarkably reduced. These results strongly suggested that the inhibition of PGE2 production by vitamin E results from the inhibition of the activities of both phospholipase A2 and cyclooxygenase.

Animals↗
PubMed1991

Examination of aggravating factors of urinary excretion of N-acetyl-beta-D-glucosaminidase after extracorporeal shock wave lithotripsy.

We measured urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion before and after extracorporeal shock wave lithotripsy (ESWL) with a view to study the underlying factors which aggravate renal impairment immediately after ESWL. The factors associated with the significant elevation of urinary NAG after ESWL included female sex, a previous history of ESWL, and urinary tract infection (UTI). By studying the backgrounds of these factors, we found that both the female group and the group with a previous history of ESWL contained significantly more patients with UTI. These findings indicate that UTI may be one of the risk factors which aggravate renal damage immediately after ESWL, and that careful management is necessary in the ESWL treatment of urinary tract stones with UTI.

Acetylglucosaminidase↗
PubMed1991

Combined therapy of interleukin 2 with cyclophosphamide or bacillus Calmette-Guérin against implanted bladder cancer cells in mice.

1 x 10(5) cells of FAMFT-induced bladder cancer cell line (MBT-2) were injected into the right leg of the C3H/He mice. 10 days later, these animals with the same tumor size were divided into four groups. Group 1 is the control with no treatment. Group 2 underwent interleukin 2 (IL-2) treatment for 10 days since the 11th day after tumor inoculation. Group 3 received just one CPM injection on the 10th day. Group 4 had a combination therapy of CPM, followed by IL-2. Group 1 and 2 exhibited enlargement of tumor size, resulting in the death of all animals. Administration of CPM led to temporary disappearance of tumor, followed by local tumor recurrence in all cases. However, combined therapy with IL-2 showed complete remission of the tumors. Natural killer cell activity measured by the 51Cr release assay of the spleen cells using Yac-1 cells as target cells 20 days after tumor inoculation was found to be significantly higher in group 2 and 4, while lymphokine-activated killer cell activity of the spleen cells against P-815 cells showed no significant difference between the four groups.

Animals↗
PubMed1991

Stone fragility--measurement of stone mineral content by dual photon absorptiometry.

We measured the mineral content of urinary tract stones by dual photon absorptiometry, which is widely used for the analysis of bone mineral content, and compared the values of the stones by dual photon absorptiometry (DPA values) with the results of an in vitro fracture study as well as those of an in vivo extracorporeal shock wave lithotripsy treatment study. The results of a preliminary experiment showed that the DPA values of 20 urinary tract stones reflected actual stone mineral content. As a result of the in vitro fracture study, the DPA value calculated by volume of a struvite stone, which was the most easily disintegrated, was the lowest (0.53 g/cm3). The DPA values of calcium oxalate monohydrate and apatite stones, which poorly disintegrated, were the highest (0.98, 1.01 g/cm3). The DPA value of calcium oxalate dihydrate, which moderately disintegrated, was 0.86 g/cm3. By the in vivo extracorporeal shock wave lithotripsy treatment study, the total DPA values of stones measured before extracorporeal shock wave lithotripsy treatment in 12 patients were 0.73 +/- 0.34 g in successful cases and 1.92 +/- 0.43 g in unsuccessful cases with a significant difference between the two (p less than 0.05). These results showed that the measurement of stone mineral content by dual photon absorptiometry was useful in predicting the fragility of stones against shock waves before performing extracorporeal shock wave lithotripsy treatment for patients with urinary tract stones.

Absorptiometry, Photon↗