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Biomedical subjects

N Tsuboi

Publications and source records attributed to N Tsuboi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Renal masses detected by general health checkup.

BACKGROUND: A total of 60,604 persons underwent a general health checkup at Toma Hospital, Saitama, Japan, between January 1993 and June 1997, and transabdominal ultrasonography (US) was performed on all persons. We investigated the usefulness of transabdominal US in detecting renal tumors during general health checkups. METHODS: A definite diagnosis was made in cases where the re-examination by US revealed calculus with acoustic shadow or a simple cyst. Computed tomography (CT) was conducted in patients suspected of having a renal tumor, and a diagnosis of renal angiomyolipoma (AML) was made if plain CT gave evidence of a fatty component. Patients diagnosed as having a renal cell carcinoma (RCC) with non-uniform enhancement underwent nephrectomy. If a definite diagnosis could not be made even by contrast CT, the monitoring by US and contrast CT once a year was continued. RESULTS: Of 97 (0.16%) patients whose transabdominal US findings indicated a diagnosis of suspected renal tumor, 58 underwent the re-examination by US; of these, CT was conducted in 47. Detailed US revealed a hyperechoic pattern in 44 patients, a mixed pattern in nine and an isohypoechoic pattern with internal echo in five. By plain CT, 24 patients were diagnosed as having AML, and two as having renal calcification. Contrast CT enabled a diagnosis of renal cyst to be made in two patients and renal tumor in 14. All 14 patients with RCC except one underwent nephrectomy, which provided pathologic evidence supporting the diagnosis. Five patients had a tumor unidentifiable by CT, with continuing periodic follow-up by US and CT. Eleven patients underwent no CT. CONCLUSION: Of the 60,604 persons who underwent a general health checkup, we found 14 cases of RCC and 24 cases of AML. As a small RCC has a favorable prognosis, patients greatly benefit from early detection; therefore, we should recognize the importance of identifying renal masses by US screening during general health checkups.

Adolescent↗
PubMed2000

Three-dimensional matrix suppresses E2F-controlled gene expression in glomerular mesangial cells.

BACKGROUND: Extracellular matrix (ECM) regulates mitogenesis of glomerular mesangial cells. Currently, however, the molecular mechanisms that mediate the control of cell growth by ECM are not fully elucidated. METHODS: The effects of structurally distinct forms of type I collagen matrix on mesangial cell proliferation and cell cycle distribution were examined. Expressions of the cell cycle-regulatory transcription factor E2F and retinoblastoma susceptibility gene family proteins were also investigated. RESULTS: Mesangial cells cultured on monomeric collagen matrix showed a substantial growth response to serum. In contrast, mesangial cells cultured on polymerized collagen matrix exhibited arrest of the cell cycle in the G0/G1 phase. The induction of the quiescent phenotype was correlated with down-regulation of E2F-1, the prototypal transcription factor that controls cell cycle progression. The suppression of E2F-1 was associated with (1) dephosphorylation of retinoblastoma susceptibility gene proteins, pRB and p130, and (2) accumulation of E2F-pRB and E2F-p130 DNA binding complexes that bind to the E2F consensus sequence located in the E2F-1 promoter. Other E2F regulatory genes, including c-myc, cyclin A, and cdc 2, were also down-regulated in mesangial cells cultured on polymerized collagen matrix. CONCLUSION: These results suggest that a three-dimensional collagen induces cell cycle arrest via suppression of E2F-controlled gene expression in mesangial cells. Dephosphorylation of pRB and p130 and subsequent generation of transrepressor complexes, E2F-pRB and E2F-p130, may be involved in this process.

Carrier Proteins↗
PubMed2000

A case of dermatomyositis associated with mechanic's hand.

A 67-year-old man was referred to the Department of Internal Medicine at Tokyo Medical University with interstitial pneumonia in July 1999. He presented with keratotic plaques on both palsm and on the ventral and lateral sides of his fingers. Erythematous keratosis was observed on the dosal aspect of his fingers and metatarsophalangeal (MP) joints. Edematous erythema was seen on the patient's chest, back, and the extensor surfaces of his arms. Electromyography revealed a myogenic pattern and an increased level of myogenic enzymes was found in the blood. Histological findings of the ventral sides of his fingers showed hyperkeratosis and parakeratosis of the dermal tissue and liquefaction degeneration of the basal layer at the papilla. Based on these findings, the patient was given a diagnosis of dermatomyositis associated with mechanic's hand. A systemic examination confirmed interstitial pneumonia and carcinoma of the duodenal papilla. Mechanic's hand is a type of dermatitis associated with myopathy first reported by Stahl et al. in patients with collagen disease. We report herein the first documented case of mechanic's hand in Asians.

Adenocarcinoma↗
PubMed2000

New monoterpene glycoside esters and phenolic constituents of Paeoniae radix, and increase of water solubility of proanthocyanidins in the presence of paeoniflorin.

Seven new monoterpene glycoside esters related to paeoniflorin were isolated from Paeoniae Radix, together with polymeric proanthocyanidins, polygalloylglucoses and 48 known compounds (a benzoylsucrose, seven aromatic acids, adenosine, nine monoterpene glycosides, eight flavan-3-ols, a catechin dimer formed by oxidation, seven proanthocyanidins, three galloylsucroses, five galloylglucoses, and six ellagitannins). The structures of the new compounds were determined by spectral investigation including two-dimensional NMR techniques. In addition, increased water solubility of polymeric proanthocyanidin in the presence of paeoniflorin was examined by n-octanol-water partition and 1H-NMR spectral experiments.

Anthocyanins↗
PubMed2000

Endoscopic treatment of vesicoureteral reflux in children with glutaraldehyde cross-linked bovine dermal collagen. Short-term results.

BACKGROUND: Endoscopic treatment using glutaraldehyde cross-linked (GAX) collagen was conducted on 4 children with bilateral primary vesicoureteral reflux (VUR)..... a 1-year-old boy and three 5- to 8-year-old girls $B!D (Ball having a history of repeated hospitalization for fever due to acute pyelonephritis, visiting as pediatric outpatients regularly and receiving antibiotics continuously. By international VUR classification, 4 ureters were grade 3, 2 grade 4, and 2 grade 5. METHODS: After nonallergy to GAX collagen was confirmed intracutaneously, a needle was used through a 9.5 Fr cystoscope channel to puncture bladder mucosa 4 to 5 mm from the affected ureteral orifice at 6 o'clock under general anesthesia; 1.1 to 1.9 ml of GAX collagen was injected immediately below affected orifices. RESULTS: Three months after surgery, voiding cystourethrography showed reflux had disappeared in 6 ureters, for a short-term success rate of 75%. VUR in the Remaining 2 ureters improved from grade 3 to 1 and from grade 5 to 4. No postoperative urinary tract infection occurred and antibiotics were stopped. CONCLUSION: Since GAX collagen is less viscous than Teflon paste, it is easily injected into submucosa, does not form granuloma or migrate to other organs, and is noncarcinogenic. Endoscopic VUR treatment using GAX collagen is indicated when less invasion and shorter hospitalization are considered, although it requires general anesthesia, which itself involves some risk.

Child↗
PubMed2000

Comparison of vectorcardiographic and 12-lead electrocardiographic detections of abnormalities in repolarization properties due to preexcitation in patients with Wolff-Parkinson-White syndrome: proposal of a novel concept of a "remodeling gradient".

Repolarization abnormalities after radiofrequency ablation in patients with manifest Wolff-Parkinson-White syndrome (WPW) have been attributed to cardiac memory of pre-existing changes in repolarization properties. We compared spatial ventricular gradient (VG) from vectorcardiograms with QRST values of 12-lead ECG in 41 patients with WPW (group A, manifest WPW due to left-sided accessory pathway (n = 20); group B, manifest WPW due to right-sided accessory pathway (n = 12); group C, concealed WPW (n = 9)) before and after ablation. Group N (n = 607) served as control. In groups A and B, the abnormalities of spatial VG and QRST values of 12-lead ECG that existed before and 1 day after ablation significantly decreased 1 week after ablation. In group C, spatial VG and QRST values of 12-lead ECG showed no significant changes. The diagnostic ability of spatial VG is almost equivalent to that of the QRST value of ECG in detecting repolarization abnormalities in patients with WPW before and after ablation. We propose a new concept of a "remodeling gradient" directing from the preexcited area to the opposite side of the ventricle as a result of preexcitation-induced electrical remodeling.

Adolescent↗
PubMed2000

[A case of prostatic small cell carcinoma].

A 66-year-old man was referred to our hospital with a complaint of lumbago. Digital rectal examination showed an enlarged, irregular prostate with stony hardness. The serum level of prostate specific antigen (PSA) was elevated. Abdominal computed tomography showed enlarged common iliac and paraaortic lymph nodes, and multiple liver metastases. Bone scintigraphy showed multiple bone metastases. Histological and immunohistochemical examinations indicated small cell carcinoma and adenocarcinoma of the prostate. Chemotherapy could not be performed due to acute hepatic failure. The patient died 1 month after his first visit.

Adenocarcinoma↗
PubMed2000

[A case of tuberculous epididymitis which was difficult to distinguish from a testicular tumor].

A 70-year-old man complaining of painless right scrotal swelling was referred to our hospital. He had a past history of left nephrectomy for renal tuberculosis at the age of 28. Power Doppler ultrasonography revealed a hypoechoic and hypovascular tumor with septa in the scrotum. We suspected a right testicular tumor and therefore, performed a right high inguinal orchiectomy. On macroscopic findings, the fluid of the tumor was yellowish and mucinous and the ipsilateral testis was remarkably atrophic. The pathological diagnosis was tuberculous epididymitis with central necrosis. In recent years, tuberculous epididymitis is rare, and this case was considered to be the first report of power Doppler ultrasonographic findings in tuberculous epididymitis.

Aged↗
PubMed1999

Localization of precise origin of idiopathic ventricular tachycardia from the right ventricular outflow tract by a 12-lead ECG: a study of pace mapping using a multielectrode "basket" catheter.

Radiofrequency catheter ablation guided by pace-mapping techniques has proven effective in eliminating idiopathic ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT). A method for rapidly identifying the origin of VT from 12-lead electrocardiogram (ECG) findings would be helpful for the catheter ablation procedure. The purpose of this study is to precisely localize the origin of idiopathic VT from the RVOT by a 12-lead ECG from a study of multipoint pace mapping. In one patient with premature ventricular complex (PVC) and 3 with VT, a "basket" catheter was deployed in the RVOT for bipolar pacing from 56 sites in the endocardium of RVOT. Under fluoroscopy the pacing sites were classified into the septum and free wall. We investigated the QRS morphology in leads, I, II, and III; the depth of the QS wave in leads aVR and aVL; and the height of the initial r wave in leads V1 and V2. Pacing was captured in 30-47 of 56 sites (54%-84%). As the pacing sites changed from the anterior to posterior of the septum, the QS notch (-) type in lead I shifted through rs to R, while a shift from R type to rR' or Rr' was noted in leads II and III. As the pacing sites changed from the anterior to posterior of the free wall, lead I showed a shift from the QS notch (+) type to R, while a shift from rR' to Rr' (or rR' unchanged) was found in leads II and III. The depth of the QS wave in leads aVR and aVL showed a tendency for aVR to be deeper than aVL toward the posterolateral attachment of both the septum and free wall, whereas aVL tended to be deeper than aVR toward the anterior attachment. The initial r waves in V1 and V2 became greater as the pacing site was positioned at a higher or more posterior location. These findings may provide more precise and clinically useful diagnostic information on the site of the origin of idiopathic VT originating from the RVOT by a 12-lead ECG.

Adult↗
PubMed1999

Elimination of non-ionic contrast medium by hemodialysis in patients with impaired renal function.

The elimination rate of iohexol, a non-ionic contrast medium, from the blood by hemodialysis, and the elimination rate of iohexol by a dialyzer were studied in 15 patients with chronic renal dysfunction who required angiography or enhanced CT. The elimination rate of iohexol was 19.8% at 15 min after the start of hemodialysis, 30.6% after 30 min, 44.2% after 1 hour, 62.1% after 2 hours and 72.9% after 3 hours. The dialyzer elimination rate was maintained at about 75% from 1 to 3 hours after the start of hemodialysis. If only about 70% of iohexol in the blood needs to be eliminated, hemodialysis for 3 hours with a blood flow rate of 120 ml/min and a dialysate flow of 500 ml/min using a 0.7 m2 cellulose triacetate membrane is sufficient.

Contrast Media↗
PubMed1999

The short-term effects of tamsulosin in Japanese men with benign prostatic hyperplasia.

We evaluated the short-term effects of tamsulosin in treating benign prostatic hyperplasia. Twenty-seven patients, aged 57 to 86 years (mean 68.4); complaining of obstructive urinary symptoms who had received no previous treatment for such symptoms were orally administered 0.2 mg of tamsulosin for 4 weeks. Symptoms (total AUA symptom score and AUA symptom subscores) and objective parameters including peak and average flow rate, and post-void residual urine rate were evaluated before and after 1, 2 and 4 weeks of treatment. The mean total AUA symptom score and the mean AUA symptom subscores for incomplete emptying and weak stream were significantly decreased after only 1 week of treatment. The mean AUA symptom subscores for intermittency, urgency and nocturia were significantly decreased after 4 weeks of treatment. The mean AUA symptom subscores for frequency and hesitancy were unchanged after 4 weeks of treatment. The mean peak and average flow rate, and post-void residual urine rate were significantly improved after only 1 week of treatment. In conclusion, tamsulosin improved not only objective parameters but also symptoms only 1 week after the start of treatment.

Administration, Oral↗
PubMed1999

[A case of extragonadal germ cell tumor with inferior vena caval tumor thrombus].

We report a case of retroperitoneal extragonadal germ cell tumor with tumor thrombus in the inferior vena cava. The patient referred to our hospital with lumbago. Computed tomography (CT) showed a bulky mass in the retroperitoneum. The levels of alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (beta-HCG) in the serum were elevated. Histological examinations indicated embryonal cell carcinoma. Bilateral testicles did not contain any palpable mass upon careful palpation. No tumor mass was detected in the bilateral testicles on ultrasonography. Clinically, the diagnosis was a retroperitoneal extragonadal germ cell tumor associated with para-aortic lymph-node involvement. After the combination chemotherapy (BEP 1 course and EP 3 courses), the tumor mass was reduced in size and the tumor marker was normalized. Retroperitoneal lymph node dissection (RPLND) was performed and tumor thrombus in the inferior vena cava was resected. There was no involvement of the viable cells in the resected tumor. The patient has been in good condition with no evidence of disease.

Adult↗
PubMed1998

Dual isotope SPECT in malignant Jacod's syndrome.

A case is presented of metastatic tumor causing Jacod's syndrome: total ophthalmoplegia, blindness, and trigeminal neuralgia. Abnormal soft tissue invading the orbital apex, anterior clinoid process, and cavernous sinus was difficult to assess by CT and MRI, but dual-isotope SPECT including Tc-99m HMDP bone imaging and Tl-201 tumor imaging strongly suggested that the cause of this rare syndrome was a small metastatic tumor. Although the therapeutic effect was also difficult to assess by anatomic imaging alone, dual-isotope SPECT after radiation therapy showed a decline of tumor viability.

Aged↗
PubMed1998

New electrophysiologic features and catheter ablation of atrioventricular and atriofascicular accessory pathways: evidence of decremental conduction and the anatomic structure of the Mahaim pathway.

INTRODUCTION: Several modalities of catheter ablation have been proposed to eliminate Mahaim pathway conduction. However, limited research has been reported on the electrophysiologic nature of this pathway in its entity. METHODS AND RESULTS: In seven patients, electrophysiologic study was performed, and radiofrequency energy was applied to investigate the electrophysiologic clues for successful ablation. In all seven patients, the Mahaim pathway was diagnosed as a right-sided atriofascicular or atrioventricular pathway with decremental properties. In two patients, two different kinds of electrograms were recorded through the ablation catheter positioned at the Mahaim pathway location: one was suggestive of conduction over the decremental portion, demonstrating a dulled potential; and the other of nondecremental conduction, demonstrating a spiked potential. All but one of the Mahaim pathways were eliminated successfully at the atrial origin where the spiked Mahaim potential was recorded. Radiofrequency energy application was performed at the slow potential site resulting in failure to eliminate the conduction over the Mahaim pathway. Conduction block at the site between the slow and fast potential recording sites was provoked by intravenous administration of adenosine, concomitant with a decrease in the amplitude of the Mahaim potential. In one patient, the clinical arrhythmia was a sustained monomorphic ventricular tachycardia originating from the ventricular end of the Mahaim fiber. CONCLUSION: The identification of Mahaim spiked potentials may be the optimal method to permit their successful ablation. Detailed electrophysiologic assessment is indispensable for successful ablation of tachycardias associated with Mahaim fibers because tachycardias unassociated with Mahaim fibers can occur despite complete elimination of the Mahaim fiber.

Adolescent↗
PubMed1998

[Clearance of gadolinium contrast agent by hemodialysis: in vitro and clinical studies].

In order to evaluate the safety and pharmacokinetics of gadolinium contrast agents in patients with hemodialysis, in vitro and clinical studies were performed. Gd-DTPA and Gd-HP-DO3A solutions were dialysed by standard methods. One classic type (cellulose acetate) and two high-performance types (PMMA and polyacrylonitrile) were used. Eleven dialysis patients underwent normal dose contrast MRI followed by usual dose hemodialysis (HD). PMMA dialysis membranes were used for 8 patients and cellulose acetate membranes for 3 patients. Serum levels of gadolinium, BUN and creatinine were analyzed before and after the 1st HD and after the 2nd, 3rd and 4th HD. Side effects and edema were carefully observed. In vitro studies showed that 11.1 hours of dialysis would be necessary to remove 97% of the injected dose of contrast agent by using a first-order kinetic model of dialysis time. When dialysis membranes and contrast agents were compared, statistically significant differences were noted between dialysis membranes and all contrast agents. In the clinical study, 79.1% of the contrast agent was dialyzed after the 1st dialysis and 99.6% after the 4th dialysis. These results showed that all contrast agents and both dialysis membranes were suitable. Neither changes in laboratory parameters nor side effects were observed. The present study suggests, consequently, there are no contraindications when using the ordinary dose of contrast agent even in patients with dialysis.

Aged↗
PubMed1997

Body-surface distribution of changes in activation-recovery intervals before and after catheter ablation in patients with Wolff-Parkinson-White syndrome: clinical evidence for ventricular 'electrical remodeling' with prolongation of action-potential duration over a preexcited area.

BACKGROUND: T-wave abnormalities after catheter ablation in patients with manifest Wolff-Parkinson-White (WPW) syndrome have been attributed to a continuation of repolarization abnormalities induced by preexcitation (cardiac memory). METHODS AND RESULTS: To clarify changes in repolarization properties, we analyzed the activation-recovery interval (ARI) obtained from body-surface maps and the relationship between the activation time (AT) and ARI in 30 patients with WPW syndrome (group A, 18 patients with manifest left-sided accessory pathway; group B, 7 patients with manifest right-sided accessory pathway; and group C, 5 patients with concealed left-sided accessory pathway) before, 1 day after, and 1 week after ablation. The ARI significantly decreased 1 week after ablation compared with before and 1 day after ablation over the preexcited area in groups A and B. Correlation coefficients between the AT and ARI showed a significantly (P<.01) stronger inverse relationship before (r=-.58) and 1 week after (r=-.64) ablation than 1 day after ablation (r=-.46) in groups A and B. In group C, the ARI and correlation coefficients between the AT and ARI showed no significant changes. CONCLUSIONS: These findings suggest a prolongation of the action-potential duration over the preexcited area before and just after ablation as ventricular "electrical remodeling," a decrease in the inverse relationship between the AT and action-potential duration 1 day after ablation, and a gradual recovery of the action-potential duration over the preexcited area and inverse relationship 1 week after ablation.

Action Potentials↗
PubMed1997

Incidence of cardiac sarcoidosis in Japanese patients with high-degree atrioventricular block.

In Japan the majority of sarcoidosis-related deaths are due to cardiac sarcoidosis. One of the most common electrocardiographic abnormalities in patients with this disease is atrioventricular block. This study surveyed the incidence of cardiac sarcoidosis in Japanese patients (40 men and 49 women; mean age, 69.1 years) with high-degree atrioventricular block who were admitted to the hospital to receive a permanent pacemaker. We excluded cases in which sarcoidosis had been diagnosed from the involvement of other organs. Patients with the characteristic signs of sarcoidosis underwent echocardiography, radionuclide imaging, and biopsy. Ten cases (11.2%) of cardiac sarcoidosis were diagnosed, most frequently in women aged 40 to 69 years (8 of 25, 32%). Thus the possibility of cardiac sarcoidosis should be carefully considered in middle-aged or elderly Japanese women who show high-degree atrioventricular block.

Aged↗