The effect of somatostatin on the production of human interferons by mononuclear cells.

Somatostatin (SMS) is a tetradecapeptide which can inhibit the secretion of a number of peptides produced by the endocrine or nervous systems. SMS 201-995 (octreotide) is a somatostatin analogue with very potent somatostatin activities. We have been investigating the effects of both SMS and octreotide on the production of human interferon (IFN). We obtained human peripheral blood mononuclear cells from normal donors and induced them to produce IFN in the presence or absence of a number of peptides possessing somatostatin activities. SMS and octreotide were shown to inhibit the secretion of INF-gamma but not IFN-alpha. Concentrations of 10(-6) M were shown to decrease yields when Concanavalin A or phytohemagglutin were used as the inducer. Higher concentrations had a progressively greater effect. No effects were observed on IFN-gamma production if interleukin 2, ionomycin, or various natural antigens were used to induce the cells. The 28-amino acid form of somatostatin had some effects on gamma IFN yields but the first 14-amino acid fragment of this peptide moiety did not. No effect of any of these compounds was observed on IFN bioactivity. These studies indicate SMS may have some regulatory action on the secretion of immunomodulators in vitro but the concentrations required are well above those encountered under physiologic circumstances, suggesting SMS may not play an important regulatory role governing such secretion in vivo.     

Personalized evolutionary hypothesis of breast neoplasm based on differential hybridization signals of subtelomeric probes

The limited availability of data on somatic gene evolution in breast cancer is challenging item to apply an appropriate clinical management for each individual. As human subtelomeric sequences are diverse‐prone and variable, they can be considered as hot spots for analysis of the health or disease status. We compared the hybridization signals of subtelomeric sequences in normal cells with those in auxiliary lymph nodes (ALNs) isolated from a single patient. Distinct signal intensities were found in all chromosomes: weak (5, 6, 9–12, and 16–19), medium (1, 5–9, 19, and X), and strong (2, 5, 9, 10, 16, and 18) intensities. Signal intensities in the patient's ALN and lymphocytes were higher than in normal tissues. The absence and presence of one or more hybridization signals and the presence of signals in the p and q arms were also variable. Whereas chromosomes 2, 3, 5, 7, 8, 10, 16, 18, 20, and X showed three hybridization spots, chromosomes 1, 4, 9, 12, 17, and 18–19 presented a reduced signal in the ALN and lymphocytes. In addition, signal intensity in the p arm was higher than in the q arm in most patients’ chromosomes. Therefore, we propose that subtelomeric hybridization be followed periodically in individuals with breast neoplasm to provide specific patterns. Such profiling could be considered as a prediction marker throughout the patients’ life. Together with the Ki67, cyclin D1, and cyclin E expression profiles, the subtelomeric hybridization profile could provide complementary information for cancer management.     

Levels of formaldehyde in residential indoor air of Gonabad,Iran

Abstract

Human health has been identified to be affected more significantly by indoor air quality. Among numerous pollutants present in indoor air, formaldehyde (FA) is of great concern because of its highly hazardous nature. The concentrations of FA were determined from 20 newly decorated homes in the city of Gonabad, Iran during 2015. It was found that the indoor air levels of FA in all the sampled houses were exceptionally high in the range of 21 to 360 µg/m³ (mean of 149.3 µg/m³). If the 24-h average concentrations of FA measured from those sites were concerned, nearly 40% of them were seen to exceed the WHO guideline values (i.e., 100 µg/m³). One of the important reasons for the high concentrations could be low air exchange rates in those houses (e.g., from 0.18 to 0.37?h^?1), high levels of humidity in the newly decorating houses and stronger sources in the indoor environment. Furthermore, its pollution in homes with natural ventilation was seen to be much higher than those of mechanical ventilation. Due to high levels of indoor FA, more effective control procedures should be developed and employed to reduce the risk associated with formaldehyde exposure.     

Study of DNA base-Li doped SiC nanotubes in aqueous solutions: a computer simulation study

Due to the importance of soluble nanotubes in biological systems, computational research on DNA base functionalized nanotubes is of interest. This study presents the quantitative results of Monte Carlo simulations of Li-doped silicon carbide nanotubes and its nucleic acid base complexes in water. Each species was first modeled by quantum mechanical calculations and then Monte Carlo simulations were applied to study their properties in aqueous solution. Solvation free energies were computed to indicate the solvation behavior of these compounds. The computations show that solvation free energies of the complexes of DNA bases with Li-doped SiC nanotubes are in the order: thymine > cytosine > adenine > guanine. The results of complexation free energies were also used to study the stability of related structures, which indicate that thymine-Li-doped SiC nanotubes produce the most stable compound among the four DNA base complexes.