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Biomedical subjects

Shingo Yamamoto

Publications and source records attributed to Shingo Yamamoto.

61 records · Page 4Linked to original sources

[A case of malignant lymphoma with bilateral adrenal involvement].

Since the adrenal gland is a common site of metastatic disease, it is sometimes difficult to find the primary lesion only by diagnostic imaging. We report a case of non-Hodgkin's lymphoma with bilateral adrenal involvement, in which percutaneous needle biopsy was useful to determine the histology.

Adrenal Gland Neoplasms↗

Comparison of the effectiveness of ET-Kyoto with Euro-Collins and University of Wisconsin solutions in cold renal storage.

BACKGROUND: Previously, we developed a new organ preserving solution, ET-Kyoto solution (ETKS), and showed that it is effective for lung and skin cold storage. Our high sodium-low potassium solution containing trehalose and gluconate is chemically stable at room temperature. In this study, the efficacy of ETKS for renal cold storage compared with Euro-Collins solution (ECS) and University of Wisconsin solution (UWS) was investigated. METHODS: A preflush of Krebs-Henseleit buffer was used before cold storage because ECS and UWS, but not ETKS, failed to be distributed thoroughly into each renal segment when directly flushed, as determined by staining with trypan blue. The kidneys were stored at 4 degrees C in each solution after the preflush and were reperfused 24 hr later for 120 min with 37 degrees C Krebs-Henseleit buffer containing albumin. For physiological evaluation, perfusion flow rates, creatinine clearance, and fractional sodium reabsorption were evaluated. Histological examination also was performed to determine tubular, glomerular, and interstitial changes. Moreover, distribution of perfusate at the beginning of reperfusion was assessed by using trypan blue. RESULTS: The kidneys preserved in ETKS and UWS showed better physiological function and less histological damage than those preserved in ECS. Furthermore, at the beginning of reperfusion using trypan blue, almost all renal segments were stained in the ETKS and UWS groups, whereas they were partially stained in the ECS group. CONCLUSIONS: These results indicate that this simple and chemically stable solution, ETKS, could be a promising substitute for UWS.

Absorption↗

Enhanced expression of plasmid DNA-cationized gelatin complex by ultrasound in murine muscle.

This study is an investigation to experimentally confirm that ultrasound (US) irradiation is effective in enhancing the gene expression of plasmid DNA. A cationized gelatin was prepared by introducing primary amino groups into gelatin. The plasmid of the LacZ gene was complexed with the cationized gelatin and injected into the femoral muscle of normal mice. Following US irradiation at the injected site of muscle, the gene expression of the treated muscle was evaluated to compare with that of the complex injection plus no US irradiation. US irradiation enabled the complex to significantly enhance the gene expression at the injected muscle, in contrast to naked plasmid DNA, although the extent depended on the experimental conditions, such as the injection dose of plasmid DNA, and the time period or timing of US irradiation. The gene-expressed area at the muscle was not changed by the time interval between the complex injection and US irradiation. Fluorescent microscopic observation revealed that the complex was homogeneously distributed in the muscle tissue around the injected site by US irradiation without any dissociation of plasmid DNA. The fluorescent image of plasmid DNA superposed on that of myosin heavy chain indicated intracellular localization of plasmid DNA. We demonstrated that US irradiation is a promising technique to enhance gene expression even in the normal muscle.

Animals↗

In vitro transfection of plasmid DNA by amine derivatives of gelatin accompanied with ultrasound irradiation.

PURPOSE: The purpose of this study is to examine the ultrasound (US)-enhanced gene expression by the complexes of a plasmid DNA with gelatin derivatives of aminization. METHODS: Gelatin derivatives with different introduced extents of ethylenediamine (Ed), spermidine (Sd), and spermine (Sm) were prepared with a water-soluble carbodiimide. The molecular size and zeta potential of the gelatin derivatives before and after complexation with the plasmid DNA were examined. After incubation with the complexes with or without US exposure, the DNA expression of rat gastric mucosal cells was measured to evaluate the effect of the type of gelatin derivatives on their gene expression. The cell uptake of the complexes, the cell viability, and the buffering effect of gelatin derivatives were examined. RESULTS: The apparent molecular size and zeta potential of gelatin derivatives became larger as their aminization extent increased although the Sm gelatin derivative of higher aminization showed a larger value than other corresponding derivatives. Irrespective of the type of gelatin derivatives, the apparent molecular size of plasmid DNA was reduced by increasing the gelatin-DNA mixing ratio to attain a saturated value of about 150 nm. The condensed gelatin-DNA complexes showed the zeta potential of 10-15 mV. The cells incubated with the complex exhibited significantly stronger luciferase activities than free plasmid DNA, and the activity was further enhanced by US irradiation. The enhancement was significant for the Sm derivative compared with the corresponding Ed and Sd derivatives. The amount of plasmid DNA internalized into the cells was significantly increased by the complexation with every gelatin derivative, whereas US irradiation did not significantly increase the DNA internalization. US irradiation had no effect on the viability of cells incubated with every gelatin derivative-plasmid DNA complex, although the viability was decreased by the complex incubation. The buffering capacity of Sm derivative was higher than that of Ed and Sd derivatives and comparable with that of polyethylene amine. CONCLUSION: Among amine derivatives of gelatin, the Sm derivative enabled the plasmid DNA to induce the US-enhanced gene expression of cells in vitro most effectively because of the superior buffering effect.

Amines↗

Dose-intensive chemotherapy with syngeneic peripheral blood stem cell support for poor risk germ cell tumor of extragonadal origin: a case report.

A variety of regimens of high-dose chemotherapy with hematopoietic stem cell support for poor risk germ cell tumors have been established. However, a series of chemotherapy steps carried out prior to the harvest sometimes leads to an insufficient number of peripheral blood stem cells. Here, we report a case of a patient who successfully underwent high-dose chemotherapy for the treatment of poor risk extragonadal germ cell tumor by receiving peripheral blood stem cell transplantation donated from his genomically identical twin brother.

Adult↗

[A case of giant perirenal malignant lymphoma: a case report].

We report a case of malignant lymphoma arising as a giant perirenal mass in a 62-year-old woman who presented with an enlarging abdominal mass. Computed tomography (CT) revealed a large homogeneous mass with a diameter of 20 cm arising in the retroperitoneum. It surrounded the left kidney without renal infiltration and accompanied with para-aortic lymph node enlargement. Compared with the renal cortex, the tumor showed a homogeneous isodense mass by plain CT and only slight enhancement by the contrast-enhanced CT. On the basis of these imaging studies, the tumor was diagnosed as lymphoma. Then, a US guided percutaneous biopsy was performed and the tumor was diagnosed as malignant B-cell lymphoma by the histopathological analysis. This patient was treated by systemic chemotherapy since tumor cells were also disseminated in the bone marrow. The tumor responded well to the chemotherapy and about 70% of regression was achieved after six courses of chemotherapy.

Female↗

[A case of urolithiasis due to vitamin D intoxication in a patient with idiopathic hypoparathyroidism].

We report a case of urolithiasis in a patient with idiopathic hypoparathyroidism treated with vitamin D therapy. A 30-year-old woman with idiopathic hypoparathyroidism, who had been treated with vitamin D therapy with 2-4 micrograms/day of alpha-calcidol for 9 years, was admitted for recurrence of bilateral renal stones and progressing left hydronephrosis. Laboratory data revealed normal serum calcium level and remarkable hypercalciuria. The dose of oral administration of alpha-calcidol was reduced to 1 microgram/day and 2 mg/day of trichlormethiazide was started. Now her serum calcium concentration and the total amount of urine calcium was completely under control. Bilateral renal stones are no longer progressive and tetany has not been recognized. We considered it essential to monitor closely not only the serum but also the urine calcium level in the vitamin D therapy for idiopathic hypoparathyroidism.

Adult↗