[The function of regulator cAxin2 in inner ear development of chick embry].

Objective:To study the mechanism of the Wnt families'negative regulator cAxin2 in early inner ear development of chick embryo.Method: Plasmid was constructed with enhanced green fluorescent protein(EGFP), cAxin2 and short hairpin RNA(shRNA), which was transfected in otic vesicle by in ovo electroporation. Expression of cAxin2，cPax2(Pared box2)，and cBMP4(bone morphogenetic protein 4) genes was investigated in the transfected oticvesicle with situ hybridization.Result:cAxin2 expression was inhibited by shRNA，cPax2 was down regulated and cBMP4 was up regulated as well as an abnormally enlarged otic vesicle was discovered in the transfected otic vesicle. Conclusion:cAxin2 is an important regulatory gene required for inner ear development.

[Gene therapy perspectives in modulation of wound healing]. / Gentherapeutische Perspektiven zur Modulation der Wundheilung.

A variety of reasons can afflict wound healing. Current research is focussed on the acceleration of wound healing by stimulating molecular processes. Gene therapy may offer completely new ways to treat chronic wounds. Possible advantages of gene therapeutic modulation of wound healing might be a long term efficiency, systemic or local regulation of gene expression and low side-effects. Current goals comprise the improvement of transfection efficiency and specificity. In vivo applications are therefore focussed on optimized inducible or even cell-type specific promotors, as well as on improved local application techniques. Studies from our laboratory demonstrate the possibility to combine modern cell culture techniques with different types of gene transfer. This enables the simultaneous grafting of manipulated cells to the wound with the continuous delivery of specific proteins of interest. Experimentally, this lead to accelerated closure of partial and full thickness animal wounds. Clinically, gene therapy for the treatment of chronic wounds seems to be a realistic goal within the next years and might be applicable for a variety of novel indications.

Effects of antipsoriatic drugs on biosynthesis of platelet activating factor by human keratinocytes.

Human keratinocytes in primary culture stimulated by Ca2+ ionophore A23187(Io) could synthesize and release a material which might aggregate aspirin-treated washed rabbit platelets and was identified as platelet activating factor (PAF) by four methods. Io stimulated the production of PAF by keratinocytes in a time- and dose-dependent manner. The PAF precursors, i.e., AAGPC and Lyso-PAF, were detected in keratinocytes. Nitrogen mustard and dexamethasone could time- and dose-dependently inhibit PAF biosynthesis from Io to induce human keratinocytes in culture. The IC50 of nitrogen mustard and dexamethasone were 6.34 x 10(-9) M and 1.005 x 10(-8) M respectively. The results showed that the synthesis and release of PAF by normal human keratinocytes may be accounted for the development of cutaneous inflammation and the pathogenesis of some skin disorders and application of drugs that inhibit PAF synthesis may be a new and effective approach to the management of some inflammatory skin diseases such as psoriasis.

[Quantitative assay of p-nitrophenol-N-acetyl-beta-D-glucosaminide in human keratinocyte culture].

Attachment and growth of human epidermal keratinocyte culture can be assayed by counting cells or measuring incorporation of radioactive nucleotides (3H-TdR) during cell proliferation. In this study a rapid colorimetric assay for human epidermal keratinocyte growth and viability has been developed based on the colour reaction of NAG (p-nitrophenol-N-acetyl-beta-D-glucosaminide). The results can be read on a scanning multiwell spectrophotometer and show a high degree of precision. The data of experiments show that the absorbance (OD) is directly proportional to the number of cells. 10(3)-10(6) cells per well (1.5 cm2) can be assayed by controlling the time of colour reaction. This method was used to measure keratinocyte proliferation in different culture systems of different culture conditions, growth factor and keratinocyte growth-promoting activity stimulations. The results were supported by counting cells, measuring of 3H-TdR incorporation, or analysing the area of keratinocyte confluents stained with Rhodanile blue. The main advantages of the colorimetric assay are its rapidity and precision, the avoidance of any radioisotope, and it is capable of handling large numbers of culture.

5p;12q translocation with manifestations of cri du chat syndrome and Marfanoid arachnodactyly.

A 12-year-old boy with a history of a mewing cry after birth, severe mental retardation, Marfanoid arachnodactyly, general osteomalacia and multiple bone fractures was found to have a de novo 5p;12q chromosomal translocation. The karyotype is 46,XY,t(5;12)(12qter----12q24.1::5p15----cen----5qt er; 12pter----cen----12q24.1). The karyotypes of other examined family members are normal. The manifestations of cri du chat syndrome are explained by the loss of a small segment of 5p15 which is responsible for the major stigmata of the syndrome, and the abnormalities of the osseous system may be the results of untreated vitamin D resistant rickets.