Takeshi Komeyama

Pharmacological evidence of distinct oci‐adrenoceptor subtypes mediating the contraction of human prostatic urethra and peripheral artery

1 The α1‐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 μm to 100 μm 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 pD2 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 α1‐adrenoceptor subtypes in the human prostatic urethra and branches of the internal iliac artery. The α1‐adrenoceptors responsible for the contraction of the human internal iliac artery branches are predominantly α1B‐subtype, whereas those in the human prostatic urethra are considered to be not α1B, but α1C or possibly α1A or α1A/D‐subtype.

Retroperitoneal Laparoscopic Adrenalectomy for Functioning Adrenal Tumors: Comparison With Conventional Transperitoneal Laparoscopic Adrenalectomy

PURPOSEnWe attempted to confirm the possibility and feasibility of laparoscopic adrenalectomy via the retroperitoneal approach, and to compare results of the transperitoneal and retroperitoneal approaches.nnnMATERIALS AND METHODSnThree men and 8 women (mean age 39.6 years) with functioning adrenocortical tumors (primary aldosteronism in 5 and Cushings 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.nnnRESULTSnAlthough the retroperitoneal approach was successful in all 5 patients with primary aldosteronism, it succeeded in only 2 of the 6 cases of Cushings syndrome. In 3 Cushings 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 Cushings 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.nnnCONCLUSIONSnRetroperitoneal laparoscopic adrenalectomy is feasible for primary aldosteronism. However, Cushings syndrome is presently a much more difficult indication than primary aldosteronism for this new operative technique.

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 Cushings 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 Cushings 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, Cushings syndrome and nonfunctioning adrenal tumors. The ultrasonic aspirator and argon beam coagulator may be useful for laparoscopic adrenalectomy.

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)

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.

Primary gastrointestinal stromal tumor in the retroperitoneum

Abstractu2002 Gastrointestinal stromal tumor (GIST) is the most frequent non‐epithelial neoplasm in the gastrointestinal tract. GIST has received much attention both for its clinical significance and biological nature, while the retroperitoneal condition identical to GIST has been rarely described. Presented herein is a case of GIST arising from the retroperitoneum in a 67‐year‐old man. The solid tumor measuring 4u2003cm was uncovered in the retroperitoneum, between the abdominal aorta and inferior vena cava, on computed tomography. The patient underwent surgical excision of the tumor. Histological examination showed proliferating spindle cells in the clearly demarcated tumor; immunoreactivity for Kit and CD34 in tumor cells confirmed the diagnosis of GIST. The histological origin of GIST is suggested to be gastrointestinal pacemaker cells, because they share specific immunoreactivity for CD117/Kit, which is also relevant to pathogenesis of GIST. The present case was a rare primary GIST in the retroperitoneum with typical immunopathological features.

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

A novel classification of α‐1 adrenoceptor subtypes (High, Low) was applied to human benign prostatic hypertrophy (BPH)tissue.

Value of Urinary Endothelin-1 in Patients with Primary Vesicoureteral Reflux

By using a radioimmunoassay specific for endothelin-1 (ET-1), we measured urinary excretion of ET-1-like immunoreactivity (LI) in 63 spot urine samples of 48 patients with primary vesicoureteral reflux (VUR). And also, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (beta-2-MG), microalbumin (Alb) and creatinine (Cr) were measured. There was no significant correlation in any of the pairs ET-1 and NAG, ET-1 and beta 2-MG, and ET-1 and Alb. Comparing the grade of reflux according to the International Classification with urinary ET-1, urinary ET-1/Cr levels in patients with grade 2, 3 and 4 VUR were higher than normal, and the ratio of more than normal urinary ET-1/Cr increased in proportion to the grade of reflux, but it conversely decreased in grade 5. In conclusion, urinary ET-1 may be an indicator of renal tubular injury in patients with primary VUR, and its meaning may be different from conventional urinary parameters.

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)

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 OReillys 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.