Metaphase and anaphase analysis of V79 cells exposed to erionite, UICC chrysotile and UICC crocidolite

The cytogenetic effects of erionite treatment of V79 cells werecompared with those of UICC crocidolite and UICC chrysotiletreatment. A significant reduction in diploid cells with anaccompanying increase in aneuploid and polyploid cells was observedwith all three treatments. In the erionite-treated cultures,an increase in aneuploid was observedy at all dose levels rangingfrom 10 to 100 µg/ml, whereas in the crocidolite- andchrysotile-treated cultures, significant increases in aneuploidywere observed at all dose levels except the low dose, 10 µg/ml.Chromatid aberrations were observed in cultures treated withcrocidolite and chrysotile and were especially pronounced atdose 100 µg/ml of chrysotile. The clastogenic effect oferionite was weaker but statistically significant at dose 100µg/ml. An extrapolation of these cytogenetic changes overdose in number of fibers suggests that erionite was more reactivethan the other two minerals in producing aneuploidy. The numberof fibers required to produce a similar degree of cytogeneticeffects was several orders of magnitude higher for chrysotileand crocidolite than erionite. These results correlate withthe higher tumorigenic potency of erionite. In general, fewercells treated with erionite entered anaphase than those treatedwith the other two minerals. As a result, abnormal anaphasesrepresenting chromosomal mis-segregation were observed onlyin the chrysotile- and crocidolite-treated cultures. To ourknowledge, this is the first report on cytogenetic effects oferionite.     

FM sonography in diffuse liver disease: prospective assessment and blinded analysis

FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.     

Development of a new wound dressing with antimicrobial delivery capability

A bilaminar wound dressing composed of an outer membrane and an inner three-dimensional matrix of a fabric or a sponge may be considered to constitute an ideal structure that promotes wound healing: the outer membrane prevents body fluid loss, controls water evaporation, and protects the wound surface from bacterial invasion, and the inner matrix encourages adherence by tissue growth into the matrix. Using this concept, we developed a biosynthetic wound dressing with a drug delivery capability. This medicated wound dressing is composed of a spongy sheet of a chitosane derivative and collagen mixture that is laminated to an antimicrobial-impregnated polyurethane membrane. In this study, a gentamycin sulfate-impregnated wound dressing was prepared and evaluated. The antimicrobial efficacy of this wound dressing was examined on an agar plate seeded with Pseudomonas aeruginosa. Also, the cytotoxicity of an antimicrobial released from this wound dressing was examined in an in vitro system with cultured skin substitutes. Both in vitro tests have shown that this wound dressing is capable of suppressing bacterial growth and minimizing cellular damage. In addition, in the treatment of wounds inflicted on rats and rabbits, this wound dressing was shown to be efficacious in covering full-thickness and split-thickness skin defects. Finally, the efficacy of this wound dressing was evaluated in a nonrandomized open-label study of 31 clinical cases. In 31 cases treated with this wound dressing, good or excellent wound healing was achieved.