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Biomedical subjects

T Nakada

Publications and source records attributed to T Nakada.

At least 469 records · Page 26Linked to original sources

Seesaw nystagmus. Role of visuovestibular interaction in its pathogenesis.

Elevation and intorsion of one eye and synchronous depression and extorsion of the other eye characterize a half cycle of seesaw nystagmus. Reversal of these movements constitutes the second half cycle, forming the "seesaw"-like movements. Based on analysis of the ocular oscillation characteristics of the cases of seesaw nystagmus reported in the literature, including the two new cases we present, we postulate that seesaw nystagmus is another type of ocular oscillation brought about by an unstable visuovestibular interaction control system. Nonavailability of retinal error signals to the inferior olivary nucleus essential for vestibuloocular reflex adaptation due to complete chiasmal dissection makes the system less stable. This system instability is further accentuated by the pursuit feedback element. The intact inferior olivary nucleus-nodulus connections in seesaw nystagmus would explain the 180 degrees phase difference that distinguishes it from the midline form of oculopalatal myoclonus, where these connections are likely disrupted.

Adult↗

[A case report of crossed renal ectopia with renal stone].

Crossed renal ectopia is a relatively rare renal anomaly. A 49-year-old man with macrohematuria and right flank pain was admitted to our hospital. Various urological examinations were carried out, and a diagnosis of left crossed renal ectopia with renal stone was made. Pyelolithotomy was performed and stone analysis revealed a calcium oxalate. In Japan, 166 cases of crossed renal ectopia have been reported and 15 of them including our case were associated with urinary tract stones.

Calcium Oxalate↗

Hyperplasia of juxtaglomerular cells and renomedullary interstitial cells after renal arterial embolization in patients with renal cell carcinoma.

Renal tissue was obtained from 36 patients with renal cell carcinoma, some of whom received renal arterial embolization. The removed specimens was examined histopathologically and the concentration of some vasoactive substances in these patients was measured. Nephrectomy alone produced no discernible changes in blood pressure, vasoactive substances determined or histopathological findings of the kidney. Renal arterial embolization raised the blood pressure in association with the elevation of plasma renin activity (PRA) and urinary prostaglandin (PG) E2 excretion. A linear relationship was found to exist between PRA and mean blood pressure (r = 0.70, p less than 0.001). Hyperplasia of the juxtaglomerular (JG) apparatus, and high granularity of sudan black B granules in renomedullary interstitial cells were confirmed in removed kidneys of patients who had received embolization alone. Subsequently high renin production would be anticipated to influence overproduction of renal PG E2 in acute ischemic kidney in patients with renal cell carcinoma, and hypertension following renal arterial embolization appears to be caused by the hyperplasia of the JG apparatus.

Aged↗

[Renal cyst puncture under ultrasound guidance: complications of ethanol injection].

Under ultrasound guidance, we treated 25 cases of renal cyst with 99% ethanol instillation to prevent the recurrence of this disease from January 1985 to June 1987. Patients' age was from 17 to 85 years old with the average age of 63 years. Twelve cases were men, and 13 cases were women. Among the 25 cases, eleven were asymptomatic and 14 showed clinical features of lumbago, microhematuria, hypertension or proteinuria. The aspirated site was the right side in 9, left side in 14 and bilateral kidneys in 2 cases. Subsequently, cyst puncture was carried out 27 times. We encountered 12 complications following puncture. These complications were derived from the puncture itself or caused by the ethanol instillation. Flank pain caused by the injection of ethanol, nausea, causalgia or a feeling of drunkenness appeared immediately after the inoculation procedure. However, no serious complications such as pneumothorax, perirenal hematoma or infection were recognized. Some complications arose in 7 cases of 9 examples (77.8%) following more than 50 ml of ethanol injection, but the complications were observed in only 5 cases of 18 examples (22.8%) following less than 50 ml of administration. Based on these findings, ethanol injection in renal cysts appears to be useful for the treatment of this disease. In case of huge cysts when more than 50 ml of ethanol, is instilled the case should be followed up carefully after the instillation procedure.

Adolescent↗

Hyperbaric oxygenation for experimental bladder tumor. II. Hyperbaric oxygenation in combination with chemotherapy in N-butyl-N-(4-hydroxybutyl)nitrosamine-induced bladder tumors.

Two series of experiments were conducted to ascertain whether hyperbaric oxygenation (HBO) treatment with or without antineoplastic chemotherapy can really suppress tumor development in N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced bladder tumor in rats. HBO treatment of 2 ATA of air saturating with 30-35% of oxygen for 90 min daily plus 0.5 mg/100 g body weight of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) administration for 5 times suppressed the neoplastic spread of the bladder for 9 weeks and reduced the bladder weight in BBN-treated rats. Similar effects were also obtained in ACNU-treated rats, but to a lesser extent. HBO treatment associated with or without doxorubicin failed to suppress tumor growth in BBN-treated animals. Based on these findings combined with the previous study (part I), HBO treatment associated with ACNU might be available for the treatment of some cases of bladder tumors.

Animals↗

[Three case reports of monorchism].

A 3-year-old boy, with left testicle absent, a 3-year-old boy with right testicle absent and a 5-year-old with left testicle absent visited our clinic. On operation the testes and the vas could not be found in the inguinal canal or in the retroperitoneal space in all 3 cases. These three cases are reported along with embryological studies.

Child, Preschool↗