Biomedical subjects
N Tsuboi
Publications and source records attributed to N Tsuboi.
[Clinical application of third generation extracorporeal shock wave lithotriptor (TRIPTER X-1) to upper urinary tract stones].
Clinical trials of the third generation extracorporeal shock wave lithotriptor (TRIPTER X-1) on 30 patients with upper urinary tract calculi were performed from May to July, 1988. Eighteen patients (60%) were free from stones and 5 (16.7%) had stone fragments less than 5 mm, the effective rate of treatment which is sum of both group being 76.7 per cent, at one month after the treatment. The effective rate was 72.7 per cent for stones in the kidney and 87.5 per cent for those in the upper ureter. And the effective rate as to stone size was 100, 66.7 and 71.4 per cent, in stones less than 1 cm, 1 cm to less than 2 cm and 2 to 2.5 cm, respectively. Although gross hematuria skin ecchymosis, pain and fever were observed as side effects, none was serious enough to be mentioned. And post operative changes in blood chemistry were mild and transient. We confirmed extracorporeal shock wave lithotripsy using this machine for upper urinary tract stones is an effective treatment without any serious side effects.
[A case of retroperitoneal schwannoma].
A 39-year-old man, who had been pointed out to have a lower abdominal mass, was admitted to our hospital. Physical examination revealed a child-head-sized mass with smooth surface in the middle part of the lower abdomen. Computerized tomographic scan showed the non-cystic mass located in the retroperitoneal space from the level of L5 to S5. An open biopsy was performed and pathological diagnosis was benign schwannoma (Antoni A and B type). Radical operation could not be performed because of his refusal. In addition to this case, 40 cases of retroperitoneal schwannoma reported in Japan are reviewed and discussed.
[243 cases of percutaneous nephrolithotomy--result of 5 years].
Between May, 1982 and April, 1987, upper urolithiasis of 247 kidneys of 243 patients, 174 male and 69 female, were treated by percutaneous nephrolithotomy (PNL). The main stone was successfully removed from 236 kidneys (about 95.5%). Seven cases of ureteral stone could not be removed by PNL, and were treated by traditional ureterolithotomy. In 3 cases of pelvic stone, the stone descended to the ureter during the PNL procedure, and was also removed by ureterolithotomy. In one case of pelvic stone, complete obstruction of uretero-pelvic junction after PNL occurred, and pyeloplasty was needed. One pelvic stone patient who had basical hypertension and arrhythmia died soon after PNL, because of acute myocardial infarction. Blood transfusion was needed in 31 cases (12.8%). The residual stones over 5 mm were noticed in 48 cases (20.3%). The most important point to succeed in PNL is to make a nephrostomy through the most suitable calyx to the stone. The easiest way to identify the location and connection of the aimed calyx with the stone in three dimensional position, is to take X-ray films in intravenous pyelograms not only from postero-anterior but also oblique positions. Additional transureteral lithotripsy (TUL) for the fragment descending to the ureter after PNL produces a much better result.
[Study on the relationship between bacteria within stones and postoperative urinary tract infection in percutaneous nephrolithotomy].
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[The influence of percutaneous nephrolithotomy on renal function evaluated by 99m-Tc-DTPA renoscintigram].
The influence of percutaneous nephrolithotomy (PNL) on renal function was evaluated by 99m-Tc-DTPA renoscintigraphy. The renoscintigram was recorded and regions of interest of both kidneys (R) and background (BKG) were settled. Renal uptake ratio was calculated by the following formula. Renal uptake ratio = (formula; see text). The renal uptake ratio of 50 patients were compared before and up to 6 months after PNL. Most cases showed an increase or no change in post-PNL renal uptake ratio in operated kidney. Five cases (10%) showed decreased renal uptake ratio of post-PNL. No risk factors for the renal damage caused by PNL such as age, sex, stone size, number of nephrostomy and course of PNL were detected when compared with increased or no change groups. In cases of complete staghorn calculi in the decreased renal uptake ratio group, compensatory hypertrophy of contralateral kidney PNL course might occur, and the function of the operated kidney might not have recovered. More during cases and longer follow-up is necessary for the recovery of renal function.
[Treatment of advanced cancer of the urinary tract with interleukin-2 (IL-2)].
Eight patients with advanced cancer of the urinary tract were treated with recombinant interleukin-2(IL-2) at our department between December, 1985 and September, 1987. Patients were given 5 x 10(5)-4 x 10(6) units of IL-2 by intravenous drip infusion daily. One of five patients who received IL-2 for over 28 days showed 62% regression in size of hepatic metastasis of bladder cancer on computed tomography and another showed marked improvement of Performance Status. The upward tendency of natural killer and lymphokine-activated killer activity of peripheral blood was observed during treatment. Fever, mental disturbance, hypotension and eosinophilia and others were recognized during administration of IL-2, and cardiac failure and disturbance of renal function were also recognized as severe side effect.
Dependence of junctional conductance on proton, calcium and magnesium ions in cardiac paired cells of guinea-pig.
1. The dependence of gap junctional conductance on the intracellular concentrations of H+, Ca2+ and Mg2+ was studied in paired myocytes dissociated enzymatically from guinea-pig ventricle. To apply an internal solution buffered to specific H+, Ca2+ or Mg2+ concentration directly to one aspect of the gap junction, the non-junctional membrane of one of the pair was mechanically ruptured. The junctional conductance was measured by clamping the membrane potential of the other cell using a two-pipette voltage-clamp method. 2. The conductance of the non-junctional membrane was kept low in comparison with that of the junctional membrane (less than 1/50) by replacing both external and internal K+ with Cs+. 3. The current-voltage (I-V) relation of the junctional conductance was linear over the potential range examined (from -100 to +100 mV). No voltage or time dependence was detected. 4. The conductance of the gap junction between the paired cells ranged from 90 to 3900 nS with a peak distribution at 1000 nS. 5. The effect of H+ was examined over the pH range 7.4-5.4, while keeping the free-Ca2+ concentration at zero, or pCa 6.3 or 7.0 using 2-10 mM-EGTA. The junctional conductance was almost constant from pH 7.4 to 6.5 and decreased in a dose-dependent manner with further acidification. There was no difference in the pH-conductance relationships at various Ca2+ concentrations. The Hill coefficient was approximately 2.4 and the half-maximum concentration (pK'H) was 6.1. 6. The closing effect of Ca2+ on the gap junction channel was examined over the concentration range from pCa 7 to 5, while keeping the pH at 7.4, 7.0 or 6.5. At each pH, increasing Ca2+ decreased the junctional conductance with similar Hill coefficients of about 3.4. The pCa-conductance relationship shifted toward a higher Ca2+ concentration range as the pH was lowered (pK'Ca = 6.6, 6.4 and 5.6, at pH 7.4, 7.0 and 6.5, respectively). 7. Increasing Mg2+ also caused a fall in the junctional conductance over the pMg range 3.0-2.0 with a pK'Mg of 2.5 (3.2 mM), and a Hill coefficient of 3.0. 8. These results suggest that there are two respective binding sites for divalent cations and H+, and that the gap junctional conductance is regulated reversibly by the ligand-receptor reactions. Comparing the threshold concentrations of Ca2+ and H+ for electrical uncoupling, it was concluded that Ca2+ plays a more important role in regulating the gap junctional conductance of cardiac cells under physiological conditions.
Inverted papilloma of the ureter with malignant transformation: a case report and review of the literature. The importance of the recognition of the inverted papillary tumor of the ureter.
Inverted papilloma of the ureter is a rare tumor generally considered to be a benign lesion. We present a case of ureteral inverted papilloma with malignant transformation and review the literature. Ten cases of ureteral inverted papillary tumors in Japan and 13 cases of inverted papillary tumors associated with malignancy in the urinary tract in the world literature have been analyzed to define their features. Inverted papillary tumors of the ureter have distinct clinicopathological features, but most are discovered retrospectively after nephroureterectomy. From the standpoint of clinicopathological features, inverted papillary tumor of the ureter should be distinguished from its exophytic counterpart with respect to the treatment. If the tumor can be diagnosed macro- and microscopically during surgery as inverted papilloma or malignant inverted papillary tumor without invasion, partial ureterectomy including the lesion may be recommended. Furthermore, we propose the hypothesis that inverted papillary tumor could be a neoplasm of basal cell origin in the transitional epithelium, termed 'basal cell urothelioma'.
Effects of activation sequence and anisotropic cellular geometry on the repolarization phase of action potential of dog ventricular muscles.
The influence of activation sequences on action potential configuration, especially in the repolarization phase, was examined in isolated canine ventricular muscles. Action potentials were recorded from the epicardial surface in the center of a preparation having nearly uniform fiber orientation (25 X 25 mm). Stimuli applied just adjacent to the recording site produced nearly centrifugal propagation. An activation sequence either parallel (longitudinal) or perpendicular (transverse) to the long axis of the muscle fibers was produced by peripheral stimulation. Action potential duration at -60 mV (APD-60 mV) during centrifugal propagation was significantly longer than that during longitudinal propagation. Further shortening of APD-60 mV was observed during transverse propagation. When a collision of longitudinal or transverse wavefronts (longitudinal or transverse collision) was produced at the action potential recording site, the shortest APD was recorded. During centrifugal propagation, action potential mapping around the stimulating electrodes revealed that APD-60 mV shortened gradually as the recording site was moved further from the stimulation site. The spatial gradient of APD was steeper in the transverse than in the longitudinal direction, causing a distortion in the repolarization sequence and the recovery of excitability near the center of the tissue. Premature stimuli applied to an area near the central stimulation site induced one-way block and circus movement of the wavefront, indicating reentry of excitation. We concluded that the activation sequence and anisotropic cellular geometry substantially affect APD, and that such a change contributes to the spatial inhomogeneity of refractoriness leading to reentrant arrhythmias.
A new radical cystectomy for advanced or multifocal urinary bladder cancer.
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[Percutaneous nephrolithotomy in the elderly].
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[Influences of percutaneous nephrolithotomy on renal function, an observation using the NAG-index and beta 2-microglobulin as indices].
To examine the influence of percutaneous nephrolithotomy (PNL) on renal function, we measured the activity of urinary N-acetyl-beta-D-glucosaminidase (NAG) and beta 2-microglobulin (beta 2MG) in patients with nephrolithiasis, before and 3, 5, 7, 14 days and 1 month after PNL. With PNL, renal function was recovered within one month, and PNL was thought to be a more protective method than pyelolithotomy. Recovery of renal function was delayed in the cases in which PNL had been attempted over three times. In the patients with preoperative high-grade hydronephrosis, the excretion of NAG and beta 2MG in the urine was delayed. NAG-index was considered to be a more sensitive parameter than beta 2MG to evaluate renal function. The NAG-index and beta 2MG values of bladder urine were in good correlation with those of nephrostomy urine 5 days or more postoperatively. Measurement of the urinary NAG-index 3, 7, 14, 30 days after PNL operation was considered valuable for determining changes in renal function.
[Antitumor effect of carboplatin and iproplatin on human urinary bladder and prostatic cancers grown in nude mice].
Antitumor effects of carboplatin and iproplatin, a second-generation cisplatin analog were studied using cisplatin sensitive human urinary bladder (NM-B-1) and prostatic cancers (PRO-1) grown in nude mice. Both NM-B-1 and PRO-1 were sensitive to carboplatin and iproplatin. The tumor-regression effect of carboplatin at the fourfold dose of cisplatin was comparable to that of cisplatin. Iproplatin at the eight to sixteen times dose of cisplatin showed a comparable tumor regression to cisplatin. The range of effective dose was wider in carboplatin than cisplatin and that of iproplatin was not so wide as cisplatin.
Transurethral enucleation of benign prostatic hyperplasia.
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[Electron microscopic study on superficial bladder epithelium in experimentally contracted and expanded states in rats].
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[Prevalence of positive rheumatoid factor and results of a follow-up study in a population of 20,000].
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Primary malignant melanoma of female urethra: report of a case and review of the literature.
We report herein one case of malignant melanoma with a survival period of more than four years, refer to its recent conception on histopathological and ultrastructural problems and its treatment, and review the literature.