Determination of rhodanese enzyme activity by capillary zone electrophoresis.

A new sensitive method has been developed for the determination of rhodanese activity. The enzymatic reactions were carried out directly in thermostatted autosampler vials and the formation of SCN- was monitored by sequential capillary zone electrophoretic runs. The determinations were performed in a 75-micron fused-silica capillary using 0.1 M beta-alanine-HCl (pH 3.50) as a background electrolyte, a separation voltage of 18 kV (negative polarity), a capillary temperature of 25 degrees C and direct detection at 200 nm. Short-end injection or long-end injection procedures were used for sample application. The method is rapid, able to be automated and requires only small amounts of sample and substrates, which is especially important in the case of highly toxic cyanide. The developed capillary electrophoretic method also has great potential for thiocyanate determinations in other applications.

Formation of iodinin by a strain of Acidithiobacillus ferrooxidans grown on elemental sulfur.

The presence of the pigment iodinin, an Acidithiobacillus ferrooxidans culture metabolite, was demonstrated after growth of bacteria on elemental sulfur. The structure of iodinin was confirmed by X-ray structure analysis; its physiological role is discussed.

[Duo-Bonharen--a new viscoelastic preparation. Experimental study]. / Duo-Bonharen--nové viskoelastikum. Experimentální studie.

The paper discusses preclinical tests of a new viscoelastic preparation for ophthalmosurgery. Experiments revealed that preparation Duo-Bonharen which contains hyaluronic acid prepared by bacterial fermentation is suited for clinical tests. After a 24-hour interval following administration into the anterior chamber it does not raise intraocular pressure. In experiments it has no side-effects on the eye. The dispersed form in a higher concentration (5%) adheres very well to ocular tissues and protects them adequately during surgery. The cohesive form in an optimal concentration (1.5%) can be rapidly removed from inside the eye. The properties of Duo-Bonharen in experiments are comparable with similar viscomaterials which are used. The new viscoelastic material Duo-Bonharen appears suitable for clinical tests in particular for cataract surgery.

Differential expression of p73alpha in normal ectocervical epithelium, cervical intraepithelial neoplasia, and invasive squamous cell carcinoma.

The TP73 gene is a member of the p53 family and through differential promoter usage and alternative splicing can encode a number of different isoforms that have distinct properties. p73 proteins are widely expressed in neural, epithelial, and hemopoietic cells and are proposed to have roles in the development and differentiation of various cell types and in tumorigenesis. The authors have developed a novel monoclonal antibody that is specific for p73alpha to study the expression of this individual isoform in normal and neoplastic cervical epithelium. In normal epithelium, p73alpha is restricted to nonproliferating cells at the base of the epithelium, whereas other p73 isoforms are found in the proliferative zones higher up in the epithelium. In cervical cancers, p73alpha expression is commonly lost, although other p73 isoforms are present at high levels. In particular, the authors found that invasive islands lose p73alpha expression when compared with the overlying intraepithelial lesion. These results show a tight regulation of p73 isoform expression in cervical epithelium and imply that different isoforms of p73 enhance or suppress neoplastic cell growth. These data raise the possibility that reactivation of p73alpha might be beneficial in cervical carcinoma. In addition, the absence of p73alpha in cervical cancer represents a potentially useful tool for the diagnosis of this disease.