Biomedical subjects

W Sakamoto

Publications and source records attributed to W Sakamoto.

At least 19 recordsLinked to original sources

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↗

PubMed1991

Linkage analysis of the nuclear homologues of mitochondrial plasmid-like DNAs in rice.

A genetical study on the nucleotide sequences of the nuclear DNAs which share homology with rice mitochondrial plasmid-like DNAs, B1, B2, B3 and B4 was carried out. Restriction fragments of the nuclear DNAs hybridized with these plasmid-like DNAs showed polymorphisms in their length between Indica and Japonica rice cultivars. The hybridized signals found specifically in Indica or Japonica cultivars segregated in the F2 population derived from a cross between these two subspecies. The observed ratio of the nuclear homologues in the F2 population demonstrated that they were transmitted according to the Mendelian inheritance. The co-segregation of homologues was examined and the linkage was detected between the B1-nuclear homologue of Japonica and the B4-nuclear homologue of Indica, and also between the nuclear homologues of B2 and B3 of Indica. The linkage between the B1-nuclear homologue of Japonica and the B4-nuclear homologue of Indica was conserved in the different rice cultivars.

Blotting, Southern↗

PubMed1991

[A case of renal pelvic squamous cell carcinoma accompanied with humoral hypercalcemia of malignancy].

A 74-year-old male was urgently admitted to our hospital because of consciousness disturbance. Laboratory data showed remarkable hypercalcemia (7.8 mEq/L), hypophosphatemia, low % TRP, low intact PTH level, normal nephrogenic cyclic AMP and normal 1,25 (OH)2D level. Serum bone Gla protein, which was thought to express osteoblastic activity, was low. Serum tartarate resistant acid phosphatase and urinary excretion of hydroxyproline, which were thought to express osteoclastic activity, were high. CT scan showed an enlarged mass in the left renal pelvis, which was found to be a squamous cell carcinoma (SCC) by biopsy through percutaneous nephroscopy. Bone scintigram appeared normal. Therefore, we diagnosed it as renal pelvic SCC with humoral hypercalcemia of malignancy (HHM) and performed left nephrectomy. After nephrectomy, serum calcium returned to normal. But after a few weeks, lung metastasis appeared and serum calcium was reelevated. As to PTH related protein (PTHrP) which was thought to induce HHM, PTHrP content of the resected tumor measured by RIA assay was 13 pmol/g wet weight of tissue, which suggested that this tumor might have been producing PTHrP.

Aged↗

PubMed1991

[Hyperthermic treatment in patients with benign prostatic hypertrophy].

Hyperthermic treatment was performed in 31 patients with benign prostatic hypertrophy (BPH). Eight patients of them had a urethral catheter because of urinary retention. The prostate was heated trans-rectally to 43-45 degrees C. The treatment consisted of 10 sessions of 60 min. each. To evaluate this treatment, the following parameters were determined before, during and one week after the last hyperthermia session: subjective symptoms score, and residual urine volume, uroflowmetry and transrectal ultrasound of the prostate as objective data. Symptoms score improve in all patients. Of 8 patients with a catheter, the catheter could be removed from 4 patients. There was no significant change in prostate volume, but significant decreases of residual urine volume, and increases of maximum flow rate and mean flow rate were observed. No adverse reactions were seen. Judging from the above results, this treatment is considered to be useful for patients with BPH.

Aged↗

PubMed1991

[Results of Kock pouch construction fully utilizing an auto-suture instrument].

From March 1987 to the end of February 1991, we performed Koch pouch construction as a urinary diversion on 20 patients who had undergone radical cystectomy due to bladder cancer. The operation was done according to the method of Skinner et al. We fully utilized an auto-suture instrument to ensure safe and stable suturing of the ileum and to shorten the operating time. It was of great concern that the staples placed at several portions might cause stone formation or aggravate infection. However, stone formation was observed only in one patient (5%) at the tip of a nipple valve in which a staple became the nucleus of the stone. Staples are usually not regarded as an obstacle as they are usually covered by the mucous membrane. In all patients, the maximum capacity of the pouch was more than 500 ml, intra-pouch pressure was kept low even when the pouch was inflated up to the maximum capacity, and reflux of urine into the upper urinary tract was not observed. As for complications, there was a slight degree of obstructive uropathy in 4 patients (20%), difficulty in catheter insertion was noted in 3 patients (15%), and stress incontinence-like urinary leakage was present in one patient when the capacity exceeded 500 ml. However, there were no complications which necessitated reoperation. In terms of blood chemistry, although there was a tendency towards a slight increase in BUN or hyperchloremia, no specific treatment was necessary as far as the kidney function was normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Inhibition of prostaglandin E2 and superoxide anion production in rat peritoneal macrophages by the calcium antagonists nifedipine and nisoldipine.

In order to clarify the possibility of an antiatherogenic action of the calcium antagonists nifedipine (CAS 21829-25-4) and nisoldipine (CAS 63675-72-9) the effect of nifedipine and nisoldipine on phorbol myristate acetate (PMA)- and calcium ionophore A23187-stimulated O2- and PGE2 production from macrophages was investigated. Nifedipine and nisoldipine inhibited dose-dependently PMA-stimulated O2- and PGE2 production, but not A23187-stimulated PGE2 production. The 50% inhibitory concentration (IC50) of nifedipine and nisoldipine for PMA-stimulated O2- production were 60 and 8 mumol/l, respectively, whereas those for A23187-stimulated O2- were 9.3 and 2.0 mumol/l. IC50 of nifedipine and nisoldipine for PMA-stimulated PGE2 production were 3.0 and 2.8 mumol/l, respectively. The release of [1-14C]-arachidonic acid from labeled macrophages stimulated with PMA was inhibited approximately by 39 to 43% in the presence of 20 mumol/l nifedipine and nisoldipine. The increase of (Ca2+)i in macrophages induced by A23187 could not be attenuated by nifedipine and nisoldipine, and (Ca2+)i level did not alter when stimulated with PMA. These results suggest that the inhibitory mechanism of nifedipine and nisoldipine for O2- production from the macrophages appears to directly inhibit the enzyme system of the NADPH-oxidase complex through the activation of protein kinase C, and that the inhibition of PMA-stimulated PGE2 production may be due to a decrease of phospholipase A2 through protein kinase C. On the basis of the inhibitory action on O2- and PGE2 production from the macrophages, a possible mechanism of antiatherogenic effect of calcium antagonists was discussed.

Animals↗

PubMed1991

[Extracorporeal shock wave lithotripsy for ureteral stones and cystine stones].

We report our experience with extracorporeal shock wave lithotripsy (ESWL) in the treatment of ureteral and cystine stones, which are known to be difficult to treat by this method. First, in order to determine the effectiveness of the ureteral catheter in the destruction of ureteral stones, we compared the clinical results of 121 patients treated without the catheter and 141 patients inserted with the catheter. There was no significant difference in the success rate between the two groups regardless of stone size, which indicates that the use of the ureteral catheter had no effect on the outcome of treatment. We then studied the clinical results of impacted ureteral stones which are especially difficult to destroy. Excretory urography was performed to non-invasively diagnose these stones, and those without visualization in the ureter below the stone were diagnosed as impacted stones and treated by ESWL without the ureteral catheter. Among the stones with a diameter of 1 to 2 cm, the success rate was significantly lower in impacted stones compared to non-impacted stone. These findings suggest that ESWL treatment without the ureteral catheter may be effective for ureteral stones with a diameter of less than 1 cm and non-impacted stones with a diameter of 1 to 2 cm, while combination therapy with other methods such as TUL may be better for other stones. We also performed ESWL on 6 patients with renal stones and 2 patients with ureteral stones which were cystine stones. Renal stones required an average 4.1 treatment with an average of 1,875 shocks per treatment, and ureteral stones required 1.5 treatment with an average of 1,833 shocks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Effects of verapamil on cyclosporine. A (CsA)-induced nephropathy in ischemic kidney model in rats: changes in systemic hemodynamics and hepatic and renal microsomal cytochrome P-450].

We have examined the effect of verapamil on CsA-induced nephropathy by measurement of systemic hemodynamics including each organ blood flow using the microsphere method in ischemic kidney model of hemi-nephrectomized Wistar rats. Hepatic and renal microsomal cytochrome P-450 contents and their enzyme activities were measured to study the correlation between CsA-induced nephropathy and induction of hepatic and renal microsomal cytochrome P-450. All rats were hemi-nephrectomized (l-nephrectomy) and were classified into the following 6 groups: 1) control groups, 2) CsA at a dose of 40 mg/kg per day orally for 7 days (CsA group), 3) Oral administration of verapamil for 7 days in the CsA group (CsA + V group), 4) 20 min clamping of the remaining right kidney pedicle (Ischemic, Is group), 5) CsA was administered in the Is group (Is + CsA group), 6) Addition of verapamil to CsA in the Is + CsA group (Is + CsA + V group). Verapamil was given in the drinking water and the average dose calculated from the amount of drinking was 4.7 +/- 1.0 mg/kg per day and 5.2 +/- 0.7 mg/kg per day for the CsA + V group and the Is + CsA + V group, respectively. CsA caused significant increases in BUN and serum creatinine (sCr) with a significant decreases in renal inulin clearance (CIn) in all groups. When compared with the Is group, CsA caused significant decreases in cardiac output and all organ blood flow especially in renal blood flow with significant increases in BUN and sCr in the Is + CsA group.2+ degree of nephropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗