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Biomedical subjects

Takuji Tsukamoto

Publications and source records attributed to Takuji Tsukamoto.

8 recordsLinked to original sources

Ectopic thyroid in an adrenal mass: a case report.

BACKGROUND: It is difficult to explain ectopic thyroid beneath the diaphragm because during the development the thyroid descends from the tongue to the anterior of the trachea. A few cases of ectopic lesions have been reported in the literature for abdominal organs including the adrenal glands, but the mechanism by which the thyroid components migrate into the abdomen has been poorly understood. CASE PRESENTATION: A 54-year-old woman was diagnosed as having an adrenal mass. Laparoscopic adrenalectomy was carried out. Microscopically, the mass was composed of normal adrenal and ectopic thyroid tissues. CONCLUSION: We herein describe the fourth case reported of ectopic thyroid in the adrenal gland.

Adrenal Gland Diseases↗

Testicular seminoma after the complete remission of extragonadal yolk sac tumor : a case report.

BACKGROUND: Between 2% and 5% of malignant germ-cell tumors in men arise at extragonadal sites. Of extragonadal germ cell tumors, testicular carcinoma in situ (CIS) are present in 31-42% of cases, and CIS are reported to have low sensitivity to chemotherapy in spite of the various morphology and to have a high likelihood of developing into testicular tumors. A testicular biopsy may thus be highly advisable when evaluating an extragonadal germ cell tumor. CASE PRESENTATION: A 36-year-old man was diagnosed as having an extragonadal non-seminomatous germ cell tumor, that was treated by cisplatin-based chemotherapy, leading to a complete remission. In the meantime, testicular tumors were not detected by means of ultrasonography. About 4 years later, a right testicular tumor was found, and orchiectomy was carried out. Microscopically, the tumor was composed of seminoma. CONCLUSIONS: We herein report a case of metachronous occurrence of an extragonadal and gonadal germ cell tumor. In the evaluation of an extragonadal germ cell tumor, a histological examination should be included since ultrasonography is not sufficient to detect CIS or minute lesions of the testis.

Adult↗

Nephrotic syndrome as a result of membranous nephropathy caused by renal cell carcinoma.

A 77-year-old woman was admitted for a renal biopsy to evaluate a case of nephrotic syndrome. In the course of the examination, a right renal tumor was incidentally found. We performed a right radical nephrectomy in advance of the renal biopsy. Histologically, the tumor was diagnosed as a renal cell carcinoma (clear cell carcinoma) and the non-neoplastic renal cell tissue showed membranous nephropathy (MN). After surgery, the nephrotic syndrome remitted without any further medical treatment and the MN was considered to be a malignancy associated syndrome. There have been few case reports in the literature regarding this association and we wish to describe another case.

Aged↗

Hypercalcemia upon recurrence of renal cell carcinoma producing parathyroid hormone-related protein.

We established a new renal carcinoma cell line that produces parathyroid hormone-related protein (PTHrP) and interleukin-6 in culture. The cellular production of PTHrP was confirmed by Northern blot analysis and immunofluorescence examination. Bone and lung metastases occurred simultaneously 3.5 years after surgery. The patient did not show hypercalcemia at this time, despite the presence of multiple osteolytic metastases. About 7 months after bone metastasis was first shown, serum PTHrP was detected by means of an immunoradiometric assay and the calcium level was found to be elevated to 3.29 mmol/l. The hypercalcemia was successfully controlled by i.v. administration of bisphosphonates.

Adult↗

[Ureteral stricture after ESWL for ureteral calculi].

BACKGROUND: There are many reports on the effects of ESWL, but few reports on the complications, especially remaining ureteral stricture after this treatment. Therefore we have retrospectively reviewed our cases to define the predisposing factors of this complication. METHODS: Since 1991 we have treated urolithiasis with ESWL using a Siemens Lithostar for the first therapy. We had 16 cases of ureteral stricture after this treatment. Ureteral stricture is the most common complication after ESWL treatment. To define the risk factor of the stricture we have compared 549 cases that were successfully treated between 1994 and 1996 without this complication. In these two groups we examined ages, sexes, chief complaints, size, position and components of the calculi, the degree of hydronephrosis, the frequency of ESWL, the presence of urinary tract infection, the duration of stone impaction and the after endourological treatment using multiple logistic regression analysis. RESULTS: Patients with the stone incidentally found and those with the UTI seemed to be more frequently associated with ureteral stricture, however there was not a significant difference. The hydronephrosis more than grade 3 (p = 0.025), the frequency of ESWL (p = 0.0325) and the after endourological treatment, especially TUL (p = 0.0184) were statistically significant among the other factors. The stricture occurred in 5 out of 29 patients with the hydronephrosis of grade 4 and 5 between 1994 and 1996. CONCLUSION: We should carefully treat patients with grade 3 or more hydronephrosis with ESWL. We should not repeatedly treat the patients with ESWL. We should take care of TUL treatment after ESWL.

Adolescent↗

Diversity of inhibitory responses to beta2-stimulants shown by term-pregnant human myometria in vitro is partly due to differences in receptor density.

OBJECTIVE: The aims of this study were (1) to evaluate the usefulness of the new beta2-adrenergic stimulant KUR-1246 as a tocolytic agent and (2) to clarify the mechanisms that underlie the diverse inhibitory effects of beta2-stimulants that are seen in human myometria in vitro. STUDY DESIGN: The displacement of tritiated ([3H]) (-)CGP 12177 (0.4 nmol/L) by KUR-1246 and other beta2-stimulants was examined with human beta(1)- and beta2-receptors present on membrane fractions. The inhibitory effects of these beta2-stimulants on the term-pregnant human myometrium were compared with the use of isometric tension recording and microelectrode methods. Finally, the relationship between [3H]dihydroaloprenolol binding and the magnitude of the tocolytic effect of isoproterenol was examined. RESULTS: KUR-1246 was approximately 80 times and 7 times more selective for beta2-receptors than isoproterenol and ritodrine, respectively. The inhibitory effect of KUR-1246 was as strong as the inhibitory effect of the conventional beta2-adrenergic stimulants. A wide range of inhibitory effects was observed, even when high concentrations of isoproterenol or KUR-1246 were applied. There was a correlation between the degree to which isoproterenol suppressed contractions and the number of [3H]dihydroaloprenolol binding sites on the membrane in each muscle strip. CONCLUSION: KUR-1246 should be a very useful beta2-adrenergic stimulant for use as a tocolytic agent because of its high selectivity for the beta2-receptor and its potent inhibitory effect. The diversity of the inhibitory effects that are induced by beta2-stimulants is at least partly due to differences in beta2-receptor density among term-pregnant human myometria.

Acetamides↗

Real-time kinetic analyses of the interaction of ricin toxin A-chain with ribosomes prove a conformational change involved in complex formation.

Ricin toxin A-chain (RTA), a ribosome-inactivating protein from seeds of the castor bean plant (Ricinus communis), inactivates eukaryotic ribosomes by hydrolyzing the N-glycosidic bond of a single adenosine residue in a highly conserved loop of 28S rRNA, but does not act on prokaryotic ribosomes. We investigated the interaction of rat liver 80S ribosomes with RTA using an optical biosensor based on surface plasmon resonance (BIAcore instrument), which allows real-time recording of the interaction. RTA was coupled to the dextran gel matrix on the sensor chip surface through a single thiol group that is not involved in the enzymatic action. The interaction of rat ribosomes with RTA, which was greatly affected by the Mg(2+) concentration and ionic strength, was usually measured at 5 mM Mg(2+), 50 mM KCl, and pH 7.5. The modes of interaction of intact and RTA-depurinated rat liver ribosomes with the immobilized RTA were virtually the same, while no considerable interaction was observed for Escherichia coli ribosomes. The interaction was not influenced by the presence of 5 mM adenine, which is higher than the reported dissociation constant (1 mM) for the adenine-RTA complex. These results demonstrate that binding of the target adenine with the active site of RTA does not contribute much to the total interaction of ribosomes and RTA. Global analyses of association and dissociation data with several binding models, taking account of mass transport, allowed us to conclude that the data were unable to fit a simple 1:1 binding model, but were best described by a model including a conformational change involved in high affinity complex formation.

Animals↗