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Biomedical subjects

N Tsuboi

Publications and source records attributed to N Tsuboi.

At least 91 records · Page 5Linked to original sources
PubMed1986

Direct measurement of the gap junctional conductance under the influence of Ca2+ in dissociated paired myocytes of guinea-pig.

A new method to measure the gap junctional conductance under the influence of a given pCa solution was described. The paired ventricular cells were enzymatically dissociated from the guinea pig and were voltage clamped. One of the pair was crushed to expose one aspect of the gap junction to the bath solution, which contained different pCa. The method disclosed a reversible effect of Ca closing the gap junctional channel.

Animals↗
PubMed1985

Percutaneous nephrolithotomy. With emphasis on large renal stones.

With utilization of safety guide wire, dilator (up to 36F), and Mazzariello-Caprini forceps, percutaneous removal of renal stone was successfully performed in 18 cases, including 5 cases with staghorn calculus, although parts of the staghorn calculus were left in 4 cases. Attempts at stone extraction were performed on the day nephrostomy was made. All of the renal stones excluding staghorn calculi were removed without disruption followed by satisfactory postoperative renal function. Unexpectedly Kocher forceps was found to be a useful and relatively safe instrument for quick fragmentation and removal of staghorn calculi.

Female↗
PubMed1985

Anisotropic conduction properties of canine ventricular muscles. Influence of high extracellular K+ concentration and stimulation frequency.

The effects of fiber direction on the conduction of excitation and the characteristics of both extracellular and intracellular action potentials were examined in isolated dog ventricular muscle preparations. Conduction velocity and amplitude of extracellular potentials during propagation in the direction parallel to the long axis of fibers (longitudinal propagation) were significantly greater than those during propagation in the direction perpendicular to it (transverse propagation). However, the maximum rate of rise and amplitude of intracellular action potential were significantly greater during transverse propagation than during longitudinal propagation. Compared with the transverse propagation, the longitudinal propagation was more susceptible to conduction failure under high extracellular K+ concentration, suggesting a lower safety factor of the latter mode of propagation in depolarized cardiac tissue. In contrast, high frequency stimulation caused a greater decrease in the conduction velocity during transverse than longitudinal propagation resulting in augmentation of anisotropic conduction properties. These results suggest that the anisotropic conduction properties of cardiac tissue may play important roles in conduction disturbances leading to arrhythmias under various pathological conditions.

Action Potentials↗
PubMed1985

[A case of renal cell carcinoma difficult to diagnose preoperatively because of hypovascular findings].

A 35-year-old man visited our out-patient clinic with the chief complaint of macroscopic hematuria. After admission to the hospital, examinations by CT scan, renal angiography, etc. revealed a hypovascular space-occupying lesion in the right kidney, but no definite diagnosis could be made; blood findings such as accentuated alpha 2-globulin and raised LDH suggested the possibility of malignancy; and right nephrectomy was performed. In view of the preoperative X-ray findings together with postoperative pathological findings, papillary renal cell carcinoma was suspected intensively. Some discussion was made on the differentiation of lesions of hypovascular to avascular tumors and the reliability of image diagnosis based on CT scan, angiography, and other methods.

Adult↗
PubMed1985

[A clinical study on tumor of the renal pelvis and the ureter].

The 39 cases of renal pelvic and ureteral tumors treated in our hospital from 1974 to 1983, were reviewed retrospectively. The 39 cases included 15 renal pelvic tumors, 21 ureter tumors and 3 ureteropelvic tumors. The incidence of these tumors was 0.15% among all new outpatients. Sex distribution was 25 males to 14 females, and mean age was 65.2 years old. Hematuria was the most frequent initial symptom and chief complaint. Of the patients, 28.6% had come to our hospital within one month after their initial symptoms appeared. "Filling defect", an important finding of IVP and RP, was revealed most frequently. The positive rate of urine cytology was 33.4%. Histological examination revealed 14 transitional cell carcinoma and 1 papilloma of 15 renal pelvic tumors and 19 transitional cell carcinoma, 1 polyp and 1 metastatic adenocarcinoma of 21 ureter tumors. Operative therapy was performed on 36 patients; 26 by nephroureterectomy with partial cystectomy. Vesical recurrence rate was 18.9%. The 5-year survival rate was 37.4% on renal pelvic tumor and 40.7% on ureter tumor. The factors, high grade, high stage, and ureteropelvic double tumor, which reflect the specificity of the malignant potential, also affected prognosis. In conclusion, post-operative adjuvant therapy was thought to be valuable in the near future.

Adult↗
PubMed1985

[Clinical study of ureteral polyp: three cases report and review].

Three cases of ureteral polyp are reported. The first case was an adult fibrous polyp. The second was the first report as a single, lower ureteral polyp in a child in Japan. The third was a granulomatous polyp accompanied by ureteral stones. About 130 cases of ureteral polyp have been reported in Japan. Although it has been classified into 4 to 7 histological types, the concept of ureteral polyp itself is confusing as its origin remains controversial.

Child↗
PubMed1985

[Severe cyclophosphamide hemorrhagic cystitis controlled with transurethral electrocoagulation: a case report].

A case of massive cyclophosphamide hemorrhagic cystitis is presented. A 47-year-old woman with Evans syndrome was treated with a total dose of 56.6 g of cyclophosphamide for 2 years. Six months after the cessation of administration, massive hemorrhagic cystitis suddenly occurred following a common cold. Embolization of bilateral internal iliac arteries was ineffective. Therefore we performed transurethral electrocoagulation broadly for bleeding mucosa. The day after operation, bleeding from the bladder remarkably decreased and further transfusions were hardly required.

Cyclophosphamide↗
PubMed1984

[Chemotherapy of disseminated germ cell testicular tumors with cis-diamminedichloroplatinum and other drugs].

The effect of single CDDP therapy and PVB therapy was examined in 7 cases of stage III germ cell testicular tumors with measurable metastases. The mean age of the patients was 30.6 years old, and their histological types of primary sites were seminoma in 3 cases, embryonal carcinoma in 2, immature teratoma in 1 case and embryonal carcinoma + teratoma in 1 case. In 1 case of seminoma, 375 mg of CDDP was administered. In 1 case of embryonal carcinoma + teratoma, 100 mg of CDDP and then 2 courses of PVB therapy were performed, and 3 courses of PVB therapy were given in all other cases. Three cases showed complete response, 2 cases partial response and 2 cases no change. Pulmonary metastatic nodules were extirpated after the PVB therapy in 1 of the cases showing no change, and the histological examination of these nodules was found to be mature teratoma. As a result, the effectiveness of the chemotherapy alone was 71.4%, and that of chemotherapy + surgical operation was 85.7%. Significance of intensive chemotherapy and necessity of extirpation of residual metastatic nodules after intensive chemotherapy in the management of advanced germ cell testicular tumors are stressed.

Adult↗
PubMed1984

[Case of immature teratoma of the testicle metastasizing as completely mature teratoma].

A case of immature teratoma of the testicle metastasizing as completely mature teratoma is presented. A 23-year-old man underwent right inguinal orchiectomy for an immature teratoma of the testicle on September 14, 1982. At retroperitoneal lymph node dissection, 12 lymph nodes were removed, all of which were negative for cancer. He was well until March 1983, when bloody sputum and left chest pain occurred. Since full lung tomography revealed two pulmonary nodules, he was treated with a course of VP-16 and three courses of vinblastine, bleomycin and CDDP. In September 1983, after completion of the combination chemo-therapy, the two pulmonary nodules were noticed to be slightly enlarging. A thoracotomy was scheduled to remove these nodules, since they were believed to be his only remaining tumors. Pathologic examination of the extirpated nodules disclosed completely benign teratoma. Mediastinal lymph nodes had no metastatic involvement histologically. It is our intention in this paper to emphasize, by means of several case reports, the frequently benign nature of these residual lesions and also to emphasize a recently recognized phenomenon--the apparent induction of benign teratomas by this intensive chemotherapy.

Adult↗
PubMed1984

[A case of a congenital unilateral multicystic kidney and a review of 126 cases in Japan].

A 3-year-old boy was admitted to our hospital with complaints of left flank mass and growth retardation. Examinations with IVP (Fig. 1), retrograde pyelography (Fig. 4) and cystoscopic examination (Fig. 3) showed a left nonopacified kidney, and right hydroureteronephrosis due to stenosis of the midureter. Two large cystic patterns were found in the left kidney by ultrasonic scanning tomography (Fig. 2); and, the left kidney was found to be occupied by a round and homogeneously low density mass by CT scanning (Fig. 6). The left renal artery was not demonstrated on the aortogram (Fig. 5). The patient was diagnosed to have a left congenital unilateral multicystic kidney, and laparotomy was performed. The left kidney was easily removed, and the part with stenosis in the right ureter was removed, then end-to-end anastomosis was performed. Grossly, two large cysts (upper and lower part) and connective tissues were found in the left kidney (Fig. 7), and the vessels of the renal pedicle were filiform. No luminal formation of the renal pelvis or ureter was found. The epithelium of the cyst wall (Fig. 8) was deciduated leaving the connective tissue and smooth muscle, as shown by the histological examination. Histological examination of the parenchymal tissue (Fig. 9) between the two cysts showed primitive glomeruli and renal tubules among abundant connective tissue, but no cartilage tissue. Statistic examination and discussion have been made of 126 cases of congenital multicystic kidney reported in Japan.

Adolescent↗
PubMed1983

[Fracture of the penis: report of 10 cases and a review of 231 cases in Japan].

Ten cases of fracture of the penis were experienced between 1961 and 1981 at our Department. In all cases, the penis was swollen and distorted by a subcutaneous hematoma. No hemorrhagic discharge from urethra was seen. The patient's age was between 19 and 57 years. The causes of these fracture were coitus in 3 cases, manipulation in 4 cases (including one masturbation case), inverting in 2 cases, and the last case resulted from the patient's rolling over in bed. Surgical repair was performed on all patients. The causes, diagnosis, therapy and prognosis of 231 cases of fracture of the penis reported in the Japanese literature between 1934 and 1982 are reviewed.

Adult↗
PubMed1982

Congenital mesoblastic nephroma.

For more than a decade congenital mesoblastic nephroma of infancy has been recognized as an entity different from Wilms tumor in its clinical and histopathologic features. However, this tumor is sometimes confused with Wilms tumor and consequently, inadvertent and vigorous therapy compatible with that for Wilms tumor is given. we reviewed the literature and analyzed 90 cases of congenital mesoblastic nephroma in the English and Japanese literature. The importance of early and accurate histopathologic diagnosis of the resected specimen to avoid inappropriate post-operative therapy is emphasized, and the peculiar features of congenital mesoblastic nephroma are characterized.

Birth Weight↗
PubMedDate not supplied

Activity of nadifloxacin against methicillin-resistant Staphylococcus aureus isolated from skin infections: comparative study with seven other fluoroquinolones.

The in vitro susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) to nadifloxacin and seven other fluoroquinolones (norfloxacin, ofloxacin, enoxacin, ciprofloxacin, lomefloxacin, tosufloxacin and sparfloxacin) was evaluated. The MRSA isolates were isolated from 114 skin infections between 1991 and 1994. Nadifloxacin exhibited the lowest minimum inhibitory concentration and there were no MRSA isolates resistant to nadifloxacin, while there were some resistant to all of the other seven fluoroquinolones. The minimum concentrations of these drugs needed to cause 50% inhibition of the isolates increased dramatically from 1991 to 1992, but has hardly changed since 1992.

Anti-Infective Agents↗