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Biomedical subjects

T Mizusawa

Publications and source records attributed to T Mizusawa.

At least 19 recordsLinked to original sources
PubMed2000

Interaction between inflammatory cells and heparin-surface-modified intraocular lens.

PURPOSE: To investigate the interaction and adherence of inflammatory cells to a heparin-surface-modified intraocular lens (HSM IOL). SETTING: Department of Ophthalmology, Tokyo Medical University Hospital, Tokyo, Japan. METHODS: Splenic mononuclear leukocytes from rats with experimental autoimmune uveitis were cultured with the optic of an HSM IOL for 96 hours. The number of adherent cells on the HSM IOL surface was measured with and without the addition of interphotoreceptor retinoid-binding protein and concanavalin A (ConA) to the culture medium. The adherent cells were observed under a light microscope or a scanning electron microscope. RESULTS: Interphotoreceptor retinoid-binding protein and ConA increased the number of adherent cells on the HSM IOL relative to the control. Adherent cells on the HSM IOL were small and round, considered to be mainly lymphocytes. CONCLUSION: Activated lymphocytes tended to adhere to the surface of the HSM IOL.

Animals↗
PubMed1999

Evidence for beta3-adrenoceptor subtypes in relaxation of the human urinary bladder detrusor: analysis by molecular biological and pharmacological methods.

The purpose of the present study was to confirm the presence of beta3-adrenoceptor subtype in the relaxation of human urinary bladder detrusor tissue by reverse transcription-polymerase chain reaction (PCR); direct sequencing of the PCR product, in situ hybridization; and isometric contraction. Using reverse transcription-PCR, the mRNAs of three receptor subtypes (beta1, beta2, and beta3) were expressed in the human urinary bladder detrusor tissue. Direct sequencing of the PCR product of the above beta3-adrenoceptor revealed no mutation in the amplified regions. In situ hybridization with digoxygenin-labeled oligonucleotide probe revealed the presence of the mRNA of beta3-adrenoceptor subtype in the smooth muscle of the urinary bladder. The relaxant effects of isoproterenol (a nonselective beta-adrenoceptor agonist); ZD7114, BRL37344, and CGP12177A (putative selective beta3-adrenoceptor agonists); and SR59230A (a putative selective beta3-adrenoceptor antagonist) were tested using an isometric contraction technique. Isoproterenol in either the presence or absence of both atenolol (a beta1-adrenoceptor-selective antagonist) and butoxamine (a beta2-adrenoceptor-selective antagonist) revealed a relaxant effect on the carbachol-induced contraction of the human urinary bladder detrusor. Both BRL37344 and CGP12177A also revealed relaxant effects on the human urinary bladder detrusor, but ZD7114 did not elicit any relaxation. These results suggest that beta3-adrenoceptor may have some role in urine storage in the human urinary bladder.

Adrenergic beta-Agonists↗
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↗
PubMed1998

Angiography of experimental autoimmune uveoretinitis with ultrastructural correlation.

BACKGROUND: Indocyanine green (ICG) angiography has been used to evaluate posterior uveitis in the clinical setting, despite the shortage of data on possible pathological correlates of observed findings. METHODS: We used both ICG angiography and fluorescein angiography to examine rats that developed a mild form of experimental autoimmune uveoretinitis (EAU) induced by immunization with interphotoreceptor retinoid-binding protein (IRBP). Angiography was performed on days 9, 10, 11 and 23 after IRBP immunization, and freshly enucleated eyes obtained on the same days were examined histopathologically by light microscopy and transmission electron microscopy. RESULTS: Diffuse dilatation and tortuosity of the retinal vessels was observed by both ICG and fluorescein angiography, with leakage from these vessels in focal areas in the periphery. In addition, deep hyperfluorescent spots in the central posterior pole, not associated with retinal vessels, were observed by ICG angiography only. These corresponded to Dalen-Fuchs-like nodules on funduscopy. On histopathological examination, eyes showed inflammatory cell infiltration around retinal vessels, disorganization of outer retinal layers, focal subretinal accumulations of cells (resembling Dalen-Fuchs nodules), and diffuse inflammatory cell infiltration in the choroid. Ultrastructural examination of a Dalen-Fuchs-like nodule revealed a mound of monocytes, appearing to contain phagosomes of lipofuscin and phospholipids, sandwiched between transformed retinal pigment epithelium (RPE) cells with disrupted apical processes and loss of basal interdigitation. CONCLUSION: These results suggest that ICG angiography may be useful in delineating certain abnormalities at the level of the RPE, in association with posterior ocular inflammation, that cannot be observed by fluorescein angiography alone.

Animals↗
PubMed1998

Videofunduscopy and videoangiography using the scanning laser ophthalmoscope in Vogt-Koyanagi-Harada syndrome.

AIM: To observe pathophysiological changes in patients with Vogt-Koyanagi-Harada (VKH) syndrome using the scanning laser ophthalmoscope (SLO) to perform videofunduscopy, and indocyanine green (ICG) and fluorescein videoangiography. METHODS: 18 patients diagnosed with VKH syndrome were studied. 15 patients were examined in both acute and convalescent phases, and three patients were examined in the convalescent phase only. Retrospective review of charts was performed to obtain data on visual acuities, clinical findings, and results of cerebrospinal fluid cytology and histocompatibility leucocyte antigen D locus testing. RESULTS: Videofunduscopy revealed abnormalities in the central macula at the level of the retinal pigment epithelium or choroid in 40% of patients in the acute phase and 83% of patients in the convalescent phase. ICG videoangiography showed irregular hypofluorescence (80%), slow or patchy filling (67%), indistinct or fewer choroidal vessels (73%), filling defects (73%), and focal leakage (33%) in patients in the acute phase. These changes improved with systemic corticosteroid treatment, although at least one ICG videoangiographic abnormality persisted into the convalescent phase in 83% of patients in the absence of clinical inflammation. In contrast, fluorescein videoangiography revealed fewer and decreased severity of abnormalities, with greater resolution in the convalescent phase when compared with ICG videoangiography. CONCLUSIONS: SLO videofunduscopy and videoangiography revealed numerous abnormalities in patients with VKH syndrome, many of which persisted well after clinical recovery, suggesting the development of permanent morphological changes in the fundus. ICG videoangiography was more sensitive than fluorescein videoangiography in delineating abnormalities in layers deep to the sensory retina.

Acute Disease↗
PubMed1998

Treatment of bilateral renal cell cancer and multiple lung metastasis: nephron-sparing surgery and resection of lung tumors after interleukin-2 therapy.

We report a case of bilateral renal cell cancer and multiple lung metastasis who was first treated with left radical nephrectomy and nephron-sparing surgery of the right kidney. Consecutive interleukin-2 administration achieved partial response in lung disease and residual tumors were surgically removed. The disease-free state has continued for 33 months.

Aged↗
PubMed1997

Plasma endothelin-1 level in patients with renovascular hypertension - does the kidney with stenosis of the renal artery upregulate production of endthelin-1?

PROBLEM: To examine the value of plasma endothelin-1 (ET-1), we measured the level of plasma ET-1 activity of peripheral venous blood and selective renal venous blood in renovascular hypertension patients, and compared that activity with corresponding renin activity and split renal function. METHODS: ET-1 level, renin activity in selective renal venous blood and peripheral venous blood, and 99mTc-dimercaptosuccinic acid renal uptake as a split renal function test were measured in 11 patients (mean 42.1 years old) with renovascular hypertension (RVH) and 6 patients with both renal cell cancer (RCC) and essential hypertension. RESULTS: 1. In patients with RVH, resting peripheral venous plasma ET-1 ranged from 0.6 to 8.1 (mean 4.07) pg/ml and was higher than the normal level (p <0.01). However, the renal vein ET-1 ratio was nor correlated with the renal vein renin ratio. 2. In patients with RCC, resting peripheral venous plasma ET-1 was not different from the normal level. There was no step-up of plasma ET-1, or renin among renal veins, or the proximal and distal parts of the interior vena cava. 3. Both renal vein renin ratio and renal vein ET-1 ratios were inversely correlated with t99mTC-dimercaptosuccinic acid renal uptake as a split renal function examination in patients with RVH. 4. The peripheral plasma ET-1 level was correlated with the degree of stenosis of the renal artery in patients with RVH of a unilateral lesion, but not bilateral lesions. CONCLUSION: These results suggest that ET-1 may take part in the hypertensive mechanisms of RVH in addition to the renin-angiotensin system, but its significance in RVH still remains to be examined.

Adolescent↗
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↗
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

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

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

Value of dimercaptosuccinic acid single photon emission computed tomography and magnetic resonance imaging in detecting renal injury in pediatric patients with vesicoureteral reflux. Comparison with dimercaptosuccinic acid planar scintigraphy and intravenous pyelography.

The value of 99mTc-dimercaptosuccinic acid (DMSA) planar renal scintigraphy, DMSA single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) in the assessment of renal injury related to vesicoureteral reflux (VUR) was examined in 60 kidneys of 32 pediatric patients (28 bilateral, 4 unilateral) with primary VUR. The results were: (1) detection of minor renal lesions was best with MRI, then DMSA-planar and DMSA-SPECT, and (2) in comparing the positive rate, DMSA-SPECT (85%) and MRI (83.3%) were superior to intravenous pyelography (55%) and DMSA-planar scintigraphy (65%). These results suggest that DMSA-SPECT or MRI may be more sensitive than DMSA-planar scintigraphy and intravenous pyelography in detecting renal injury related to VUR in pediatric patients.

Child↗
PubMed1994

Measurement of urinary endothelin-1-like immunoreactivity and comparison with other urinary parameters in patients with primary vesicoureteral reflux. A preliminary report.

By using a radioimmunoassay specific for endothelin-1 (ET-1), we measured urinary excretion of ET-1-like immunoreactivity in 63 spot urine samples of 48 patients with primary vesicoureteral reflux (VUR). Urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (beta 2-MG), microalbumin (Alb), and creatinine (Cr) were also measured. There was no significant correlation in any pairs of ET-1 and NAG, ET-1 and beta 2-MG or ET-1 and Alb. In patients with grade 2, grade 3, and grade 4 VUR, urinary ET-1/Cr was significantly higher than normal (p < 0.05). Comparing the grade of reflux according to the International Classification with urinary ET-1/Cr, 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 distal renal tubular or collecting duct injury in patients with primary VUR.

Acetylglucosaminidase↗
PubMed1994

[Laparoscopic management for nonpalpable testis].

In this series, we investigated the efficacy and advantage of laparoscopy for management of nonpalpable testis. Laparoscopic examination was performed in 10 boys, involving one with bilateral nonpalpable testis and 9 with a unilateral nonpalpable testis and a contralateral normal one, between August 1991 and September 1993 in our institution. Three testis were diagnosed as intraabdominal and 8 testis were diagnosed as probably intracanalicular with laparoscopy. Two boys with 3 intracanalicular testis underwent laparoscopic clipping of testicular vessels, and about 6 months later, they underwent the second stage of 2-stage Fowler-Stephens orchiopexy. Eight boys, diagnosed as probably intracanalicular type by laparoscopy, underwent surgical exploration with inguinal incision. Of 8 patients, only 1 boy underwent 1-stage orchiopexy, and the other 7 boys underwent orchiectomy because their gonads were extremely hypoplastic. About 1 year after orchiopexy, 3 testes were normal in both size and location. Laparoscopy seems to be useful for both evaluation and treatment of the nonpalpable testis.

Adolescent↗
PubMed1993

Laparoscopic adrenalectomy for primary aldosteronism: a new operative method.

From January 17, 1992 to January 16, 1993, laparoscopic adrenalectomy was performed in 7 patients (3 men, 4 women) with primary aldosteronism ranging in age from 35 to 65 years (mean 48.7 years). Five of the adrenal lesions were on the left side and two were on the right. Five to six trocar-sheath units were used, and adrenal tumors were successfully removed with adjacent normal adrenal glands in all patients. The operative time ranged from 165 to 572 min (mean 302 min), operative blood loss was between 50 and 450 ml (mean 217.2 ml), and there was no major complication. In conclusion, laparoscopic adrenalectomy is a safe alternative operative method for primary aldosteronism, although application of this technique to other types of adrenal lesions remains to be examined.

Adrenal Gland Neoplasms↗