Ubiquity of chaotic magnetic-field lines generated by three-dimensionally crossed wires in modern electric circuits

We investigate simple three-dimensionally crossed wires carrying electric currents which generate chaotic magnetic-field lines (CMFLs). As such wire systems, cross-ring and perturbed parallel-ring wires are studied, since topologically equivalent configurations to these systems can often be found in contemporary electric and integrated circuits. For realistic fundamental wire configurations, the conditions for wire dimensions (size) and current values to generate CMFLs are numerically explored under the presence of the weak but inevitable geomagnetic field. As a result, it is concluded that CMFLs can exist everywhere; i.e., they are ubiquitous in the modern technological world.

Cavernous nerve graft reconstruction using an autologous nerve guide to restore potency

OBJECTIVE

To present our experience of cavernous nerve graft reconstruction, using an autologous nerve vein-guide technique, to restore potency.

PATIENTS AND METHODS

Prostate cancers frequently require radical resection involving one or both cavernous nerves that usually results in erectile dysfunction; nerve grafting has been used to restore erectile function, but clinical results are unsatisfactory owing to inadequate surgical techniques. In all, eight patients with prostate cancer who required radical resection involving one cavernous nerve had sural nerve grafting, with two or three sutures using the autologous vein-guide technique, in our unit between 2004 and 2005. Because of the difficulty of performing microsurgical manoeuvres deep within the pelvic cavity, the nerve anastomosis might be unsatisfactory.

RESULTS

Seven of the eight patients had spontaneous erectile activity after grafting and six of these patients were able to have intercourse.

CONCLUSION

Sural nerve grafting using the autologous vein-guide technique is simple, has minimal morbidity, and yields good outcomes.

The preventive effect of green tea on the gap junction intercellular communication in renal epithelial cells treated with a renal carcinogen

OBJECTIVE

Clinical studies imply that (-)-epigallocatechin-3-gallate (EGCG), a main ingredient of green tea catechins, has a chemopreventive action against cancers and suppresses the proliferation of cancer cells. However, there is no report about its chemopreventive effect for renal cancer. We previously determined that renal carcinogens suppressed the gap junction intercellular communication (GJIC) of renal epithelial cells. In this study, we investigated the effect of EGCG on the GJIC of renal epithelial cells treated with a renal carcinogen.

MATERIALS AND METHODS

Mardin-Darby canine kidney (MDCK) cells were used to determine the protective effects of EGCG on dimethylnitrosamine-induced alteration of GJIC and connexin 43 (Cx 43). The maximum concentration of EGCG was determined by the lactate dehydrogenase assay method. The scrape-loading dye transfer method was used to assess the expression and cellular localization of Cx 43. The phosphorylation status of Cx 43 was determined by Western blot analysis.

RESULTS

The optimal noncytotoxic concentration of EGCG was determined to be 10 microg/ml. The levels of GJIC and Cx 43 expression were markedly decreased in MDCK cells exposed to dimethylnitrosamine. A 12-h pretreatment with EGCG greatly ameliorated the GJIC-inhibitory effects of dimethylnitrosamine.

CONCLUSION

These results suggest that the preservation of GJIC may indicate the chemopreventive effect of green tea on renal epithelial cells treated with a renal carcinogen in vitro.

TAC-101, a novel retinobenzoic-acid derivative, enhances gap junctional intercellular communication among renal epithelial cells treated with renal carcinogens

[4-3,5-Bis(trimethylsilyl)benzamido] benzoic acido] (TAC-101), which exhibits an anti-tumor effect, can bind to retinoic acid receptors (RARs). It has retinoid-like properties, such as chemopreventive action against cancer cells. The up-regulation of connexin (Cx) expression by retinoids is well known in various epithelial cells. In this study, we investigated whether TAC-101 up-regulates gap junctional intercellular communication (GJIC) in renal epithelial cells exposed to the renal carcinogens. Madin Darby canine kidney (MDCK) cells were incubated with TAC-101 for 3 days, then briefly exposed to renal carcinogens potassium bromate (KBrO3) or dimethylnitrosamine (DMN). TAC-101 increased the expression of connexin 43 protein without affecting Cx43 phosphorylation and prevented inadequate Cx43 localisation caused by KBrO3 or DMN. Consequently, TAC-101 prevented the disruption of GJIC in MDCK cells. These data suggested that TAC-101 enhanced GJIC by up-regulating Cx43 expression and that TAC-101 might be useful for the prevention of renal cell carcinoma.

[Retroperitoneal xanthogranuloma: a case report]

A 48-year-old man was admitted to our hospital for lumbago. Computerized tomographic (CT) scan, aortography and venacavography indicated a solid retroperitoneal tumor at the right renal hilus. The tumor was removed and right nephrectomy was conducted. Some of the tumor remained owing to strong adhesion to the inferior vena cava and lumbar spine. Histological diagnosis of the resected tumor was retroperitoneal xanthogranuloma. One year after surgery, the CT scan revealed a gradual decrease in size of the remaining retroperitoneal mass.