Optimum microcurrent stimulation intensity for galvanotaxis in human fibroblasts.

OBJECTIVE: In this study, we develop methods to measure galvanotaxis of fibroblasts and determined the optimum conditions of electrical stimulation. METHOD: An inverted 35mm dish containing cell suspensions (3×105 primary human skin fibroblasts, DMEM, and 10% FBS) was placed on the centre of a 100mm dish. The 35mm dish was removed 24 hours later, and culture medium was added to the 100mm dish. Fibroblasts were randomised (double-blind) into three groups, where electrical stimulation was given at varying intensities: 0UA (control), 50UA, and 100UA. Electrical stimulation (frequency=0.3Hz) was conducted, for a duration of 4 hours, with platinum electrodes in a CO2 incubator. We took pictures immediately before and 20 hours after stimulation. We calculated the migration ratio to the negative pole by dividing the area of attached fibroblasts after stimulation with that before stimulation. RESULTS: The migration ratio to the negative pole was significantly higher in the 100UA group than in the control group (p<0.05). The ratios were 0.902±0.292 in the control group, 1.128±0.253 in the 50UA group, and 1.24±0.300 in the 100UA group. CONCLUSION: This study observed the change in cell proliferation during the initial 24-hour period after plating and was thus able to quantitatively evaluate the migration. The results suggest that a low-intensity direct current promotes migration to the negative pole of human dermal fibroblasts, which is charged with positive electricity. Several clinical reports using the methods in this study showed the microcurrent efficacy for pressure ulcer healing. Electrical stimulation based on our in vitro experiment might be important for the development of physical therapy for pressure ulcers.

Isolation of two novel genes, down-regulated in gastric cancer.

Using a differential display technique, we identified two genes that are down-regulated in human gastric cancer tissue as compared to normal gastric mucosa. The down-regulated expression of these genes in gastric cancer tissue was confirmed by northern blotting analysis and RT-PCR. One, CA11, was a novel gene expressed predominantly in the stomach and was depleted in all of the gastric cancer cell lines examined. The other gene, GC36, was homologous to the digestive tract-specific calpain gene, nCL-4. The expression of both GC36 and nCL-4 was suppressed or depleted in gastric cancer cell lines of differentiated and poorly differentiated types. This is the first report of genes, the expression of which is down-regulated with considerable frequency in gastric cancer.

[Effect of blood conservation in open-heart surgery: a comparison of 3 different methods].

Conventional blood conservation techniques have been insufficient to decrease blood transfusion requirement in open-heart surgery. Blood conservation and erythropoietin administration were performed to avoid homologous blood transfusion. Intraoperative autotransfusion has been routinely used in cardiac operations with cardiopulmonary bypass in our hospital. To evaluate the effect of conservation techniques, 286 patients were divided into four groups. In group I (23 patients), autologous whole blood was drawn and saved one to two weeks before operation. In group II (50 patients), erythropoietin preparation was given subcutaneously once a week and autologous blood conservation was also performed in the same manner as group I. In group III (48 patients), intra-operative hemodilutional autologous blood transfusion was performed. In group IV, as a control group (165 patients), only intra-operative autotransfusion was used. Homologous blood transfusion was avoided in 83% of group I patients, in 90% of group II, in 82% of group III, and 29% of group IV. In addition, in group II the hemoglobin value at the time of discharge was significantly higher than those of other groups (p < 0.05-0.01). Thus, conventional blood conservation techniques plus subcutaneous administration of erythropoietin was very effective to increase the rate of "non-blood" open-heart surgery.

Morphological changes of cochlea in a strain of new-mutant mice.

The hearing ability and histological characteristics of the cochlea of a strain of new-mutant mice were analyzed. This new mutant arose as a spontaneous mutation in the C3H/He stock. The genetic mode is autosomal recessive and the animals show abnormal behavior such as circling, head-tossing and hyperactivity. The audiological findings exhibited no recordable auditory brain stem response (ABR) in any homozygotes at ages ranging from 11 days to 117 days. For morphological examination, we used 36 homozygote with ages ranging from 10 days to 18 months. The primary morphological abnormalities were observed in the organ of Corti. The stereocilia of the outer hair cells showed disarray throughout the whole cochlea, although outer hair cell cytoplasm became fully developed, including the nerve terminals. Age-dependent degeneration of the outer hair cells subsequently occurred from the basal to the apical part of the cochlea. The earliest change demonstrated in the outer hair cells was cuticular degeneration. Although the abnormalities of the inner hair cells occurred late, a complete loss of inner and outer hair cells was demonstrated. The stria vascularis was well preserved at a later age as were spiral ganglion cells. These histological findings confirm that this mouse is classified as a neuroepithelial-type mutant. As this animal was expected to have a single gene abnormality, molecular genetic studies on this animal can provide important information on the nature of histological changes of the hair cell from a mode of gene action.