H Bansal | PubMed Health

PubMed2003

Modulation of macrophage structure and function by low level He-Ne laser irradiation.

Studies have shown that He-Ne laser irradiation can affect the biological functions of macrophages. The aim of the present study was to investigate the effect of He-Ne laser irradiation on the various functional parameters of macrophages and look for possible correlations in the effects to understand the mechanisms involved. Mice peritoneal macrophages were irradiated with a He-Ne laser (632.8 nm, approximately 10 W m(-2)) at energy densities ranging from 100 to 600 J m(-2) and the activities of lysozyme and cathepsin, phagocytosis, and cell spreading (markers of cell activation), as well as changes in NAD(P)H autofluorescence, were monitored. He-Ne laser irradiation was observed to lead to significant changes in all the parameters investigated. While lysozyme activity and spreading of the peripheral membrane were found to increase with the irradiation dose over the dose range investigated, the phagocytotic activity of macrophages, the activity of cathepsin, the observed decease in cell membrane fluidity and the observed increase in NAD(P)H level showed a peak at 200 J m(-2). Possible reasons for and the significance of the observed correlations are discussed.

Animals↗

PubMedDate not supplied

A solid liquid extraction and preconcentration method for the atomic absorption spectrometric determination of trace cobalt in various alloys and biological samples.

Cobalt is quantitatively retained as cobalt-2-nitroso-4-sulfonic acid (nitros-S)-tetradecyldimethylbenzylammonium (TDBA+) ion-pair complex on microcrystalline naphthalene in the pH range 6.2-9.0 from a large volume of its aqueous solution of various complex samples. After filtration, the solid mass consisting of cobalt complex and naphthalene is dissolved in 5 ml of dimethylformamide (DMF) and the metal is determined by flame atomic absorption spectrometry (FAAS). Cobalt complex can alternatively be quantitatively adsorbed on tetradecyldimethylbenzylammonium chloride-naphthalene adsorbent packed in a column and determined similarly. The calibration curve is linear over the concentration range 0.2-11.5 micrograms of cobalt in 5 ml of the final DMF solution. In this case, 0.2 microgram of cobalt may be concentrated in a column from 250 ml of aqueous sample where its concentration is as low as 0.8 ng/ml. Eight replicate determinations of 3.0 micrograms of cobalt in the final DMF solution give a mean absorbance of 0.045 with a relative standard deviation of 1.8%. The sensitivity for 1% absorption is 59 ng/ml. The interference of a large number of anions and cations on the determination of cobalt has been studied and the optimum conditions developed utilized for its trace determination in various alloys and biological samples. The method may also be used for the determination of cobalt in some environmental samples.

Alloys↗