Efficacy and design requirements of UV light cabinets for disinfection of exchangeable non-sterilizable "dental objects".

Non-sterilizable items such as prosthodontics items constitute a high risk of transmitting dangerous pathogens, including Coronavirus, between patients and healthcare personnel. Although UV rays are recognized for their germicidal efficacy, large and expensive UV devices previously hindered their adoption in dental offices. During the COVID-19 pandemic, small UV devices became available for domestic use, albeit with varying designs and effectiveness. Our study assesses the disinfection capacity of a UV light cabinet for four dental materials and discusses crucial design features for effective performance. Specimens of each material (silicone impressions, stone cast, acrylic denture base, and indelible pencils) were contaminated with Escherichia coli Bl21, and randomly divided into three study groups: UV device (UVG), impressions disinfection solution (SG), and control (CG). The experiment was repeated thrice, and disinfection efficacy assessed by colony forming units (CFU) count. A 2.5-min UV exposure achieved full disinfection for all materials. Significantly different results were found between groups (p < 0.05, one-way ANOVA, Tukey HSD), except for indelible pencils, where UVG and SG were both highly effective. UV cabinets surpass SG's disinfection efficacy. Compact UV devices can offer affordable, portable, and efficient disinfection for non-sterilizable dental objects, with careful consideration of wavelength, exposure, intensity, and safety.

Official urges Persian Gulf states to blacklist AIDS patients.

AIDS: Persian Gulf countries still stigmatize people with AIDS (PWAs) and single them out for punishment. Dubai's police chief, Brigadier Khahi Khalfan Tamim, recently recommended blacklisting PWAs to the Gulf Cooperation Council and recommended enacting tougher legislation in dealing with PWAs who knowingly spread the disease. He also urged police to play a bigger role in combating prostitution. In addressing the AIDS issue, the United Arab Emirates has undertaken a strict blood surveillance program to reduce the transmission of HIV through transfusions and has launched an anti-AIDS campaign in conjunction with the World Health Organization to increase awareness. Tamim urged greater anti-AIDS campaigns targeting youth.^ieng

Immunochemical and enzymatic studies on the soluble antigens of normal human kidney.

The antigenic composition of the soluble extract from normal human kidney was determined with the combined techniques of immunological absorption, immuno-diffusion and immunoelectrophoresis. The kidney extract contained at least eleven non-serum, tissue antigens; some of them were found in the extracts of other organs, but three were kidney-specific. None of the soluble tissue antigens from human kidney was characterized as a lipoprotein; however, three of them stained with the reagent for glycoproteins. Esterase activities were also demonstrated in four non-serum, renal antigens, one of which was present only in the kidney extract and absent in the other organs extracts.

[Physical and chemical properties of tryptophenases of five species of Enterobacteriaceae]. / Propriétés physiques et chimiques des tryptophanases de cinq espèces d'Entérobactériaceae

The molecular weight, sedimentation coefficient, and amino acids composition were determined on five tryptophanases (TPases) from Escherichia coli B and E. aurescens, Shigella alkalescens, and Proteus vulgaris and P. morganii. These TPases have identical sedimentation profile and coefficient (9.6 S), and the same molecular weight (220 000). Each enzyme is constituted of four identical subunits having a molecular weight of 55 000. The amino acids composition of these TPases is very similar, with the exception of P. morganii and P. vulgaris TPases which present significative variations in basic amino acids and tryptophan content. The species differentiation of the coli group cannot be made on their TPase characteristics only, contrary to P. morganii and P. vulgaris which can be differentiated between them and from the coli group.

[Differentiation of tryptophanases of five species of Enterobacteriaceae by sulfhydryl groups]. / Distinction des tryptophanases de cinq espèces d'Entérobactériaceae par les groupements sulfhydryles

We have studied the sulfhydryl groups (-SH) on the tryptophanases (TPases) from Escherichia coli B. and E. aurescens, Shigella alkalescens, and Proteus vulgaris and P. morganii. The coli group and the P. morganii apo TPases have 20 -SH groups per mole of enzyme, where as P. vulgaris apoTPase has 16. In coli group TPases, there are 16 -SH groups on the mole surface and they are all implicated in the activity and the enzyme-substrate bond. Proteus morganii TPase has 8 surface -SH groups, 4 of which are implicated in the activity; the remaining 12 -SH groups are located inside the mole and take part in the activity and the enzyme-substrate bond. Proteus vulgaris TPase has 4 surface -SH groups which are constructive of the enzyme structure, whereas the 12 remaining -SH groups are located inside the mole and take part in the activity and the enzyme-substrate bond. It is concluded that Proteus TPases are molecules which have inverted quaternary structure in comparison to those of the coli group. The studied TPases have four subunits, each of them is constituted of one polypeptidic chain having a molecular weight of 55,000.

[The effect of pyridoxal phosphate on the tryptophanases of five species of Enterobacteriaceae]. / Effet du phosphate de pyridoxal sur les triptophanases de cinq espèces d'Eenérobactriaceae

Escherichia coli B and E. aurescens, Shigella alkalescens, and Proteus vulgaris et P. morganii tryptophanases (TPases) were studied for the spectral forms of the enzyme. The pH effect on the absorption spectrum and on the enzyme specific activity revealed that the coli group TPases are identical with but differ from Proteus TPases which differ themselves. The coli group TPases attach 4 mol of pyridoxal phosphate (PLP)/mol of enzyme, independently of the pH in the presence of K(plus) ions, and 9 mol of PLP/mol of enzyme must be reduced to achieve complete inactivation. The Proteus TPases attach 4 mol of PLP/mol of enzyme at PH 6.8, and 3 mol of PLP/mol of enzyme at pH 7.8 in K(plus) buffer. In P. morganii, 7 mol of PLP/mol of enzyme must be reduced to inactivate the enzyme, whereas P. vulgaris TPase cannot be completely inactivated by this method. These five TPases attach only 3 mol of PLP/mol of enzyme in a Na(plus) buffer, independently of the pH.