[Association between duration of daily visual display terminal [VDT] use and sleep disturbances among bank tellers in Sanandaj-Kurdistan of Iran in 2010-2011]

Visual display terminals [VDT] are standard equipment for many office workers. Their use, however, may increase the risk of developing adverse conditions related to vision, the musculoskeletal system, and mental health such as insomnia. In this study, we examined the relationship between duration of daily VDT use and insomnia in bank tellers. In this cross-sectional study, 382 bank tellers working with VDT who met our inclusion criteria were selected randomly. Their demographic data, sleep quality, and stress information were collected by AIS and DCM model questionnaires. We used SPSS 15 software for data processing. Chi-square and independent t-test were used for data analysis. The results showed that the insomnia symptoms score were significantly higher in the participants using VDT more than 6 hours/day [P<0.001]. To protect bank tellers from VDT adverse effects, we recommend restriction of daily work time in these terminals to less than 6 hours, and planning for work-rest periodic times during working shift

Production and purification of polyclonal antibodies against human lymphocytes [ALG]

Anti-lymphocyte globulin [ALG] is a polyclonal antibody to surface markers of human lymphocyte that is produced in rabbit. ALG is one of the immunosuppressive agents which have been used to prevent organ allograft rejection, treatment of aplastic anemia and some of autoimmune disorders. ALG causes elimination of human lymphocytes from the peripheral blood circulation, regulation of cytotoxic activities and apoptosis. The aim of this study was to produce ALG in country. At the first lymphocytes of 20 healthy people were mixed together after separating with Ficol-Hypaque [D=1.077]. About 4x10[9] lymphocytes were injected to rabbit via marginal vein. Following repetitive immunizations of the animal, ALG was produced and, then its purification was performed using simple, rapid and inexpensive method, ion exchange chromatography. Serum of the immunized rabbit was precipitated with ammonium sulfate in the final concentration of 50%. The precipitant rich in immunoglobulin [ALG] was rewashed with 50% ammonium sulfate, dialyzed against phosphate-buffered saline and applied to ion-exchange chromatography on DEAE-Sepharose 6B. ALG riched fraction was eluted with Tris-Phosphate buffer [pH=8.1] in the first step. Then second fraction containing residual ALG was exited from the column applying stepwise concentrations of 50 mM NaCl. The efficiency of 1/40 dilution of the produced ALG was proved by histocompatibility assays in compare with standard ALG. Also its purification was confirmed by SDS-PAGE in reduced conditions. Hence even 40 times diluted produced ALG can act like standard ALG, so it could be used as positive control in histocompatibility assays, indicating production of ALG is more economical and in the benefit of self sufficiency. In addition purified ALG can be prescribed as immunosuppressive medicine

Production of monoclonal antibody against human immunoglobulin E

Immunoglobulin E is one of the five classes of immonoglobulins that plays an important role in allergic diseases. Production of monoclonal antibodies by a single clonotype against different epitopes of immunoglobulin E has high priority in development of diagnostic kits. In this study, an attempt was made to produce monoclonal antibodies against human immunoglobulin E. Balb/c mice were immunized with semipurified immunoglobulin E and spleen cells fused with SP2.0 mouse myeloma cell line in the presence of polyethylene glycol. Supernatant of hybridoma cells was screened for detection of antibody by enzyme linked immonosorbent assay method. Cloning of selective high absorbance wells were done with limiting dilution method. The suitable clone [monoclone] was selected by enzyme linked immunosorbent assay and confirmed by immunoblot. The subclass of the chosen monoclonal antibodies was determined and the clones freezed and kept in liquid nitrogen. During this study three successful fusions were carried out, which resulted in development of 156 clones with high production of anti-IgE. Fourteen clones with the highest titres were selected for cloning. After limiting dilution more than 100 monoclonal antibodies were produced and the suitable one [G10F7] I.E.; the clone which displayed the high absorbance in reaction with purified immunoglobulin E and the lowest cross-reactivity with immunoglobulin M, immunoglobulin G and immoglobulin A was chosen. In immunoblotting, presence of high density band in reaction with immunoglobulin E was confirmed. The suitable mab was shown to be IGG1 subclass with kappa light chain. It seems that, this mab could be successfully used in diagnostic kits