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T Komeyama

Publications and source records attributed to T Komeyama.

At least 19 recordsLinked to original sources
PubMed1999

Pharmacological and molecular biological evidence for ETA endothelin receptor subtype mediating mechanical responses in the detrusor smooth muscle of the human urinary bladder.

The aim of this study was to characterize endothelin receptor subtypes of the detrusor muscle of the human urinary bladder. The receptor subtypes mediating endothelin (ET)-1-induced activity in the human detrusor smooth muscles have been characterized using isometric contraction and reverse transcription-polymerase chain reaction (RT-PCR). ET-1 (a non-selective ET receptor agonist; 10(-10) M to 10(-6) M) exhibited concentration-dependent contractions in human urinary bladder with a plateau at concentrations above 3x10(-7) M. Neither IRL1620 nor sarafotoxin S6c (both ETB-selective agonists; 10(-10) M to 10(-6) M) elicited contractile activity in the human urinary bladder detrusor smooth muscle. FR139317 (an ETA-selective antagonist; 10(-7) M to 10(-5) M) produced a marked shift to the right of the ET-1 concentration-response curve in human urinary bladder detrusor smooth muscle (from the Schild plot TpA2=7.96; slope=0.95). In contrast, RES701-1 (an ETB-selective antagonist; 10(-7) M to 10(-5) M) had no effect on the ET-1 concentration-response curve. RT-PCR revealed positive amplification of ETA receptor mRNA fragment, but not ETB. These results indicate that the ET-1-induced contractile effects of urinary bladder detrusor smooth muscle seem to be mediated mainly by the ETA receptor, not by the ETB receptor.

Aged↗
PubMed1997

Alpha-1 adrenoceptor subtypes (high, low) in human benign prostatic hypertrophy tissue according to the affinities for prazosin.

BACKGROUND: A novel classification of alpha-1 adrenoceptor subtypes (High, Low) was applied to human benign prostatic hypertrophy (BPH) tissue. METHODS: Human BPH specimens were examined by a radioligand binding assay method using 3H-prazosin, and those data were compared with preoperative therapies. RESULTS: (1) Scatchard analysis showed a high-affinity site (Kd:27.18 +/- 6.41 pM; Bmax:9.29 +/- 0.98 fM/mg protein; mean +/- SE) as alpha 1H, and a low-affinity site (Kd: 4088.0 +/- 744.34 pM, Bmax: 140.81 +/- 19.98 fM/mg protein) as alpha 1L subtype, for prazosin. (2) The Kd and Bmax were not different in the nontreated group (n = 5), alpha 1 blocker group (n = 5), and antiandrogen group (n = 5), in either alpha 1-high affinity or alpha 1-low affinity subtype. (3) Phenoxybenzamine had different pKi values for the above two adrenoceptor subtypes. Scatchard analysis showed that alpha 1-high affinity binding site disappeared in the presence of 1 microM of phenoxybenzamine, and the Kd and Bmax values in the presence of 1 microM of phenoxybenzamine were almost identical to the alpha 1-low affinity site of the two subtypes. CONCLUSIONS: Human BPH tissue possesses both alpha 1H- and alpha 1L-adrenoceptor subtypes according to the affinities for prazosin, and only the alpha 1H subtype can be completely inhibited by some concentration of phenoxybenzamine. Treatment by alpha 1 blocker may not change the conditions of alpha 1-adrenoceptors in prostatic tissue.

Adrenergic alpha-Antagonists↗
PubMed1997

Retroperitoneal laparoscopic adrenalectomy for functioning adrenal tumors: comparison with conventional transperitoneal laparoscopic adrenalectomy.

PURPOSE: We attempted to confirm the possibility and feasibility of laparoscopic adrenalectomy via the retroperitoneal approach, and to compare results of the transperitoneal and retroperitoneal approaches. MATERIALS AND METHODS: Three men and 8 women (mean age 39.6 years) with functioning adrenocortical tumors (primary aldosteronism in 5 and Cushing's syndrome in 6) underwent laparoscopic adrenalectomy via the retroperitoneal approach using a balloon dissection technique and a newly developed ultrasonic aspirator. Results were compared to those of 27 cases of transperitoneal laparoscopic adrenalectomy. RESULTS: Although the retroperitoneal approach was successful in all 5 patients with primary aldosteronism, it succeeded in only 2 of the 6 cases of Cushing's syndrome. In 3 Cushing's syndrome cases the retroperitoneal approach was changed to the transperitoneal laparoscopic approach due to difficulty in exploration. Open laparotomy was required in 1 case of left Cushing's syndrome because of an inadvertent pancreatic injury. Subcutaneous emphysema developed in 6 patients without hypercapnia or prolonged postoperative symptoms. Mean operative time and blood loss, and time to oral intake and ambulation were 248.3 minutes, 151.4 ml., and 1.55 and 2 days, respectively. There was no difference between retroperitoneal and conventional transperitoneal laparoscopic adrenalectomy in regard to these factors or to convalescence. CONCLUSIONS: Retroperitoneal laparoscopic adrenalectomy is feasible for primary aldosteronism. However, Cushing's syndrome is presently a much more difficult indication than primary aldosteronism for this new operative technique.

Adrenal Cortex Neoplasms↗
PubMed1995

Laparoscopic adrenalectomy for Cushing's syndrome: comparison with primary aldosteronism.

BACKGROUND: Removal of adrenal adenoma of Cushing's syndrome is believed to be more troublesome than primary aldosteronism because of large amount of retroperitoneal adipose tissue and bleeding from the fat. The objective of the present study was to evaluate the feasibility of laparoscopic adrenalectomy for Cushing's syndrome and comparison of the results of laparoscopic adrenalectomy between primary aldosteronism and Cushing's syndrome. METHODS: From January 17, 1992, to July 31, 1993, laparoscopic adrenalectomies for functioning adrenal lesions were performed in 14 patients (five men, nine women), three of whom had Cushing's syndrome and 11 of whom had primary aldosteronism. RESULTS: Operative times (mean +/- SD) for primary aldosteronism and Cushing's syndrome were 269.0 +/- 100.9 minutes and 253.7 +/- 57.9 minutes, respectively. No difference was noted in operative time, operative bleeding, and postoperative recovery between them. However, the weight of removed tissue from patients with Cushing's syndrome (20.00 +/- 8.17 gm) was greater than that from those with primary aldosteronism (6.64 +/- 2.01 gm). No operative complications occurred in patients with Cushing's syndrome. Ultrasonic aspiration and argon-beam coagulation were useful for laparoscopic adrenalectomy in patients with Cushing's syndrome. CONCLUSIONS: Cushing's syndrome may be a good indication for laparoscopic operation.

Adenoma↗
PubMed1994

Correlation of upper and lower urinary tract function in patients with neurogenic bladder: evaluation using simultaneous measurement of cystometry and diuresis renography with full and empty bladder.

Diuresis renography and water filling cystometry were simultaneously performed with the bladder full and with the bladder empty. The findings of diuresis renography with a full bladder were compared with those of diuresis renography with an empty bladder, in 9 patients (4 male and 5 female, mean 24.4 years old) with neurogenic bladder dysfunction. According to O'Reilly's classification, the findings of diuresis renography with a full bladder were significantly worse than those of diuresis renography with an empty bladder, regardless of cystometry patterns and bladder compliance. These results suggest that in patients with neurogenic bladder dysfunction, a full bladder in itself can cause deterioration of the upper urinary tracts, regardless of bladder pressure and bladder compliance.

Adolescent↗
PubMed1994

Does gadolinium-diethylene triamine pentaacetic acid enhanced MRI of kidney represent tissue concentration of contrast media in the kidney? In vivo and in vitro study.

Although Gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) has been used as a contrast material in magnetic resonance imaging (MRI), it is known that contrast enhancement effect is not uniform if the concentration of Gd-DTPA increases beyond some levels. In this study, to evaluate the proper pulse sequences for dynamic MRI in the human kidney, the concentration of Gd-DTPA was quantitatively measured by inductively coupled plasma (ICP) emission spectrometry in human biological samples after administration of Gd-DTPA. The signal intensity of MRI in the solutions of several concentrations of Gd-DTPA was measured. The results were that in using a low magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 mumol/g under saturation recovery sequences (flip angle = 60 degrees or 90 degrees). Using a high magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 or 3.0 mumol/g under spin-echo or gradient-echo sequences. Gd-DTPA concentration of the renal cortex ranged from 0.132 to 0.152 mumol/g tissue at 5 min after IV injection of Gd-DTPA 0.05 mmol/kg body weight in six patients with adrenal tumor or renal cell cancer, and one patient with both urinary bladder cancer and prostatic cancer. Six of the patients showed normal renal function and the other had renal insufficiency (GFR = 25 ml/min/1.48 m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Experience with 17 cases of laparoscopic adrenalectomy: use of ultrasonic aspirator and argon beam coagulator.

Between January 17, 1992 and July 31, 1993, 11 patients with primary aldosteronism, 3 with Cushing's syndrome and 3 with a nonfunctioning adrenal tumor underwent laparoscopic adrenalectomy at our university hospital. In every patient adrenal tumor was removed successfully with adjacent normal adrenal tissue. The initial 10 operations were performed without use of an ultrasonic aspirator or argon beam coagulator, and the subsequent 7 procedures were done with those items. There was no difference between the groups in intraoperative blood loss or operative time. However, the tumors in the former group were significantly smaller than those of the latter group (mean 6.70 gm. versus 13.43 gm., respectively, p < 0.05, t test). For right tumors the argon beam coagulator was useful to resect or coagulate the liver, since adrenal tumors were sometimes tightly attached to the liver and upward retraction sometimes caused liver laceration. In obese patients or those with Cushing's syndrome the ultrasonic aspirator was useful to remove retroperitoneal fat surrounding the adrenal tumor without injury to the small vessels. The mean hospital stay for these 17 patients (11.63 days) was significantly shorter than that of 16 patients with corresponding adrenal tumors undergoing open removal during the last 5 years (17.32 days, p < 0.05 t test). In conclusion, laparoscopic adrenalectomy is feasible for the surgical treatment of primary aldosteronism, Cushing's syndrome and nonfunctioning adrenal tumors. The ultrasonic aspirator and argon beam coagulator may be useful for laparoscopic adrenalectomy.

Adrenal Gland Neoplasms↗
PubMed1994

Changes in urinary excretion of endothelin-1-like immunoreactivity in patients with testicular cancer receiving high-dose cisplatin therapy.

To assess the value of endothelin-1 (ET-1) in estimating renal injury in patients receiving high doses of cisplatin, urinary excretion of ET-1-like immunoreactivity (U-ET-1), beta 2-microglobulin (U-beta 2-MG), and N-acetyl-beta-d-glucosaminidase (NAG) were measured before, 1 week after, and 2 weeks after the administration of cisplatin in eight patients with testicular cancer (mean age, 33.3 years). Levels of U-ET-1/creatinine (Cr) during and 1 week after cisplatin treatment were significantly higher than before cisplatin treatment. There were no differences in U-ET-1/Cr levels during, 1 week after, and 2 weeks after cisplatin treatment. The level of U-beta 2-MG/Cr during cisplatin treatment was significantly higher than levels before, 1 week after, and 2 weeks after treatment. However, there were no differences in U-beta 2-MG/Cr levels before, 1 week after, and 2 weeks after cisplatin treatment. The level of U-NAG/Cr during cisplatin treatment was higher than levels before, 1 week after, and 2 weeks after treatment; U-NAG/Cr during cisplatin treatment was higher than levels before, 1 week after, and 2 weeks after treatment; U-NAG/Cr gradually decreased after cisplatin treatment. Among the three parameters, only U-ET-1/Cr maintained a higher level after cisplatin treatment. The U-beta 2-MG/Cr level returned most rapidly to normal after cisplatin treatment. Although U-ET-1/Cr did not show any significant correlation with U-NAG/Cr (r = 0.282, P = NS), it showed a significant correlation with U-beta 2-MG/Cr (r = 0.454, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1994

Urinary endothelin-1-like immunoreactivity in young male patients with testicular cancer treated by cis-platinum: comparison with other urinary parameters.

1. Urinary excretion of endothelin-1-like immunoreactivity and urinary excretion of other parameters (beta 2-microglobulin, N-acetyl-beta-D-glucosaminidase and microalbumin) were measured before, within 1 week after and 2 weeks after the administration of cis-platinum in five young male patients with testicular cancer (mean age 33.0 years) and were compared. 2. Urinary endothelin-1-like immunoreactivity/creatinine during, 1 week after, and 2 weeks after cis-platinum treatment was significantly higher than before cis-platinum. There was no difference in urinary endothelin-1-like immunoreactivity/creatinine during, 1 week after and 2 weeks after cis-platinum. 3. Among the four parameters, urinary endothelin-1-like immunoreactivity/creatinine showed the highest level after cis-platinum treatment. Urinary beta 2-microglobulin/creatinine most rapidly returned to normal levels after cis-platinum. 4. Although urinary endothelin-1-like immunoreactivity/creatinine did not show any significant correlations with urinary N-acetyl-beta-D-glucosaminidase (r = 0.291, not significant) or urinary microalbumin/creatinine (r = 0.076, not significant), it showed a significant correlation with urinary beta 2-microglobulin/creatinine (r = 0.475, P < 0.05). 5. These results suggest that endothelin-1 may be a sensitive urinary parameter in detecting cis-platinum-induced renal tubular injury.

Acetylglucosaminidase↗
PubMed1994

Pharmacological evidence of distinct alpha 1-adrenoceptor subtypes mediating the contraction of human prostatic urethra and peripheral artery.

1. The alpha 1-adrenoceptor subtypes mediating contractions of the smooth muscle in human prostatic urethra and branches of internal iliac artery were characterized in isometric contraction experiments. 2. Phenylephrine produced concentration-dependent contractions in both the urethra and artery. These responses were competitively inhibited by prazosin, WB4101 and 5-methyl-urapidil, and the slopes of Schild plots for all these antagonists were close to unity. 3. The pA2 values for prazosin were not significantly different between the urethra (9.42 +/- 0.11; mean +/- s.d.) and artery (9.50 +/- 0.27), while the pA2 values for WB4101 and 5-methyl-urapidil in the human prostatic urethra (8.94 +/- 0.19 and 8.42 +/- 0.14, respectively) were significantly greater than in the branches of human internal iliac artery (7.94 +/- 0.21 and 7.43 +/- 0.22, respectively; P < 0.01). 4. Pretreatment with chlorethylclonidine (CEC) at concentrations ranging from 0.1 microM to 100 microM attenuated the maximum contraction to phenylephrine in a concentration-dependent manner in both the urethra and artery. However, the urethra was significantly less affected by CEC than the artery. The pD'2 values (negative logarithm of the molar concentration of antagonist which reduced the maximum contraction to one half) in the urethra and artery were 4.35 +/- 0.27 and 5.20 +/- 0.37, respectively (P < 0.01). 5. The present results indicate that there are distinct populations of alpha 1-adrenoceptor subtypes in the human prostatic urethra and branches of the internal iliac artery. The alpha 1-adrenoceptors responsible for the contraction of the human internal iliac artery branches are predominantly alpha 1 B-subtype, whereas those in the human prostatic urethra are considered to be not alpha 1 B, but alpha 1 c or possibly alpha 1 A or alpha 1A/D-subtype.

Aged↗
PubMed1994

Changes in urinary excretion of endothelin-1-like immunoreactivity before and after unilateral nephrectomy in humans. Comparison with other urinary parameters and unilateral adrenalectomy.

To assess the value of endothelin-1 (ET-1) as a parameter of renal functional overload and the process of hyperfiltration, urinary excretion of ET-1-like immunoreactivity (U-ET-1) and urinary excretion of other parameters [beta 2-microglobulin (beta 2-MG), N-acetyl-beta-D-glucosaminidase (NAG), albumin (Alb) and 24-hour creatinine clearance (Ccr24)] were measured before, 1, 2 and 7 days after unilateral nephrectomy in 15 patients with unilateral renal lesions (renal cell cancer, renal pelvic cancer, ureteral cancer and renal tuberculosis) and after unilateral adrenalectomy in 5 patients with adrenal lesions. In the nephrectomy group (NX), Ccr24 significantly decreased at 1 and 2 days after the operation, but the other 4 parameters significantly increased after the operation as compared to preoperative values. In the adrenalectomy group (ADX), neither Ccr24 nor ET-1/Cr showed any change after the operation, but the other 3 parameters (beta 2-MG/Cr, NAG/Cr and Alb/Cr) significantly increased. Comparing the NX and ADX groups, both ET-1/Cr and beta 2-MG/Cr in NX were significantly higher than in ADX after the operation. On the other hand, neither NAG/Cr nor Alb/Cr in NX differed from values in ADX. Comparing ET-1/Cr and other parameters, only beta 2-MG showed a positive significant correlation. These results suggest that U-ET-1 may be an indicator of functional overload of the kidney.

Acetylglucosaminidase↗
PubMed1994

Dissociation of selective renal venous plasma endothelin-1 activity and corresponding plasma renin activity in a patient with hypertension, severe stenosis of unilateral renal artery and ipsilaterally decreased renal function.

Plasma endothelin-1 (ET-1)-like immunoreactivity in selective renal venous blood and peripheral venous blood was measured and compared with plasma renin activity and aldosterone level in a 26-year-old woman with suspected renovascular hypertension due to stenosis of the left renal artery. Although there was no significant step-up in plasma renin activity between the right and the left renal vein, left/right ratio of plasma ET-1 in the renal vein was 2.18. This case suggests that ET-1 may be one of the hypertensive mechanisms of suspected renovascular hypertension in addition to the renin-angiotensin system.

Adult↗
PubMed1994

Incidence of pouch stones and risk factors for urolithiasis in patients with continent urinary diversion or neobladder using intestine.

Urinary risk factors and inhibiting factors for urolithiasis, such as oxalate, calcium, phosphate, uric acid, citrate, and magnesium, were examined in 12 patients receiving continent urinary diversion, neobladder, or augmentation cystoplasty using intestine. These data were compared with the incidence of pouch stone formation. Ten (83.3%) of 12 patients had at least one risk factor, and 5 (41.7%) of 12 had two or more risk factors. Pouch stone developed in 4 (80%) of 5 patients with two or more risk factors, and in none of 7 patients with one or zero risk factors. The incidence of pouch stone in the former group was significantly higher than in the latter group. These results suggest that urinary reservoir operations should not be performed in patients with two or more risk factors for urolithiasis.

Female↗
PubMed1994

Simultaneous measurement of cystometry and diuresis renography during full and empty bladder in neurogenic bladder patients: a preliminary report.

In 9 patients (4 male and 5 female; mean 24.7 years old) with neurogenic bladder dysfunction, diuresis renography and water filling cystometry were simultaneously monitored with a full and empty bladder, and findings of diuresis renography with a full bladder were compared with those of diuresis renography with an empty bladder. According to O'Reilly's classification, findings of diuresis renography with a full bladder were significantly worse than those of diuresis renography with an empty bladder, regardless of cystometry patterns and bladder compliances. Although every kidney without hydronephrosis on intravenous pyelogram showed normal diuresis renography with an empty bladder, some kidneys with hydronephrosis showed an obstructive pattern even with an empty bladder. These results suggest that in some patients with neurogenic bladder dysfunction, deterioration of the upper urinary tract occurs more easily with a full than with an empty bladder, regardless of bladder pressure and bladder compliance.

Adult↗