Preventative effect of diclofenac sodium and/or diltiazem in rats with epidural fibrosis.

OBJECTIVE: Spinal epidural fibrosis is commonly seen after laminectomy. There is not yet proven any agent preventing fibrosis in clinical usage. We used diclofenac sodium and diltiazem, which are fibrosis inhibitors. METHODS AND MATERIALS: 40 rats were divided into four groups of equal numbers: control, diclofenac sodium, diltiazem, and diclofenac sodium + diltiazem. Laminectomies were performed at L5 and L6. After a 4 week period, the rats were decapitated and the vertebral column blocks were removed for histopathologic examination. Fibrosis percentage, spread of fibrous regions, and fibroblast numbers were evaluated in each group and compared between the groups. RESULTS: The distribution of epidural fibrosis density, percentage of fibrosis, and distribution of fibroblasts in the diclofenac sodium + diltiazem group were significantly lower than in the other groups. The fibroblast numbers of the diltiazem, and diclofenac sodium + diltiazem groups were significantly lower than in the other groups. CONCLUSION: Diclofenac sodium + diltiazem used together provided better outcomes because each of them prevented fibrosis via different ways, probably through synergistic action (Tab. 5, Fig. 3, Ref. 43).

A high temperature cell for simultaneous electrical resistance and neutron diffraction measurements.

An in situ cell that allows the electrical resistance of a sample pellet to be measured while performing neutron diffraction experiments has been developed at the ISIS pulsed neutron source. The sample is held between two spring loaded platinum electrodes embedded in a boron nitride clamp assembly with the resistance measured using the four-probe method. An outer quartz glass jacket allows the atmosphere within the sample enclosure to be controlled, and the entire device can be accommodated within a standard ISIS neutron furnace for measurements at temperatures up to 1270 K. The operation of this cell is illustrated using data for the structural, magnetic, and electrical properties of chalcopyrite CuFeS(2) collected over the temperature range of 398-873 K on the Polaris powder diffractometer at ISIS.

Human papillomavirus type 16 E6 and E7 cooperate to increase epidermal growth factor receptor (EGFR) mRNA levels, overcoming mechanisms by which excessive EGFR signaling shortens the life span of normal human keratinocytes.

Epidermal growth factor receptor (EGFR) levels are dramatically increased in human keratinocytes (HKc) immortalized with full-length human papillomavirus type 16 (HPV16) DNA (HKc/HPV16), but increases in EGFR levels actually precede immortalization. In some normal HKc strains, acute expression of HPV16 E6 (but not HPV16 E5, HPV16 E7, or HPV6 E6) from LXSN retroviral vectors produced an increase in EGFR mRNA levels detectable at 24 h and stable for up to 10 days after infection. However, about one-half of the individual normal HKc strains we analyzed proved unresponsive to E6 induction of EGFR mRNA despite the robust expression of E6 and degradation of p53. E6 responsiveness of normal HKc strains correlated inversely with initial EGFR levels: although HKc strains expressing relatively low basal EGFR levels grew poorly and tolerated the infection protocol with difficulty, they responded to E6 with an increase in EGFR mRNA and protein and with robust proliferation. However, those HKc strains expressing high basal EGFR levels grew well, but did not respond to E6 with increased EGFR levels or with proliferation. Immunostaining of paraffin-embedded foreskin tissue for the EGFR confirmed that there is an intrinsic interindividual variability of EGFR expression in HKC: These results prompted us to investigate the effects of overexpression of the EGFR in normal HKC: Infection of normal HKc with a LXSN retrovirus expressing the full-length human EGFR cDNA resulted in a dramatic reduction in growth rate and a shorter life span. Although acute expression (1-10 days after infection) of HPV16 E7 alone did not induce the EGFR, acute expression of E6 and E7 together increased EGFR levels in normal HKc unresponsive to E6 alone. Also, HKc infected with E7 alone expressed increased EGFR levels at early stages of extended life span (at passage 9 after infection), and HKc immortalized by HPV16 E7 alone expressed EGFR levels comparable with those of E6/E7-immortalized cells. These results support a key role of the EGFR in HPV16-mediated transformation of HKC: In addition, these data show that normal HKc do not tolerate excessive EGFR levels/signaling, and such intolerance must be overcome in order for HKc to become immortalized by HPV16. We conclude that both E6 and E7 contribute to increasing EGFR levels, but with different mechanisms: although E6 can increase EGFR levels, it cannot overcome the resistance of normal HKc to excessive EGFR signaling. On the other hand E7, which alone does not acutely increase EGFR mRNA or protein, allows for EGFR overexpression in normal HKC:

Retinoic acid resistance at late stages of human papillomavirus type 16-mediated transformation of human keratinocytes arises despite intact retinoid signaling and is due to a loss of sensitivity to transforming growth factor-beta.

In our in vitro model of human cell carcinogenesis, normal human foreskin keratinocytes (HKc) transfected with human papillomavirus type 16 DNA (HKc/HPV16) progress toward malignancy through several phenotypically defined and reproducible "steps" that include immortalization, growth factor independence (HKc/GFI), differentiation resistance (HKc/DR), and ultimately malignant conversion. While HKc/HPV16 are very sensitive to growth inhibition by all-trans-retinoic acid (RA) at early passages, they lose their sensitivity to RA during progression in culture. However, gel mobility shift assays using the retinoid response elements DR1 and DR5 showed no changes in binding activity of nuclear extracts obtained from HKc/HPV16 at different stages of in vitro progression. Similarly, Western blot analyses for retinoic acid receptor gamma-1 and the retinoid X receptors failed to reveal any decreases in the levels of these retinoid receptors throughout progression. In addition, luciferase activity driven by the SV40 promoter with a DR5 enhancer element was activated following RA treatment of HKc/DR that were resistant to growth inhibition by RA. Since RA induces transforming growth factor-beta2 (TGF-beta2) in normal HKc and HKc/HPV16, we investigated whether this response changed during progression. Again, RA induced TGF-beta2 mRNA in early and late passage HKc/HPV16, HKc/GFI, and HKc/DR approximately to the same extent, confirming that the RA signaling pathways remained intact during in vitro progression despite the fact that the cells become resistant to growth inhibition by RA. We then investigated the sensitivity of HKc/HPV16 to growth inhibition by TGF-beta. While early passage HKc/HPV16 were as sensitive as normal HKc to growth inhibition by TGF-beta1 and TGF-beta2, the cells became increasingly resistant to both TGF-beta isotypes during in vitro progression. In addition, while both RA and TGF-beta produced a decrease in the levels of mRNA for the HPV16 oncogenes E6 and E7 in early passage HKc/HPV16, this effect was also lost at later stages of progression. Finally, blocking anti-TGF-beta antibodies partially prevented RA inhibition of growth and E6/E7 expression in early passage HKc/HPV16. Taken together, these data strongly suggest that inhibition of growth and HPV16 early gene expression in HKc/HPV16 by RA is mediated by TGF-beta and that a loss of RA sensitivity is linked to TGF-beta resistance rather than alterations in RA signaling.

Value of color Doppler sonography in the diagnosis of venous impotence.

The gold standard in the diagnosis of venous impotence is cavernosometry. But a less invasive and time-consuming screening test for patients with a high probability of venous impotence is required. Therefore we evaluated 82 men with erectile dysfunction by color Doppler sonography after intracavernosal injection of 60 mg papaverine. 28 of them who had a poor erectile response but sufficient arterial inflow were included in this study. 6 patients who were previously found to have psychogenic impotence formed the control group. After pharmacological stimulation by papaverine, all patients were examined for 20 min by color Doppler sonography in order to detect diastolic flow velocities in the cavernosal arteries and erectile responses. Both groups of patients underwent pharmaco-cavernosometry in a blind fashion afterwards. The diagnosis of venous impotence with color Doppler sonography was confirmed by dynamic pharmaco-cavernosometry in 25 of 28 (89%) and 6 of 6 (100%) subjects of the study and control groups, respectively. Statistically, in the diagnosis of venous dysfunction, color Doppler sonography had a sensitivity of 100%, specificity of 66.6%, accuracy rate of 91% and a positive predictive value of 0.892. The gold standard in the diagnosis of venous impotence is still cavernosometry, but it seems that color Doppler sonography may provide a sensitive assessment of penile venous competence.

Comparison of AR-based algorithms for respiratory sounds classification.

Respiratory sounds of pathological and healthy subjects were analyzed via autoregressive (AR) models with a view to construct a diagnostic aid based on auscultation. Using the AR vectors, two reference libraries, pathological and healthy, were built. Two classifiers, k-nearest neighbour (k-NN) classifier and a quadratic classifier, were designed and compared. Performances of the classifiers were tested for different model orders. The best classification results were obtained for model order 6.