Nature of the afterglow of marine algae

Excitation spectra and light curves were studied in three species of marine algae at monochromatic light excitation of the second-range afterglow. It was shown that light curves were satisfactorily described by an equation similar to the equation of enzyme catalysis with low light intensity of half-saturation (about 0.5 W X m-2). Shapes of the excitation spectra and spectral curves of quantum yield of the second-range afterglow was analysed considering the early non-linearity of its light curves. It was found that the results obtained and the literature data on a relatively high quantum yield of the second-range afterglow in the region of absorption of long-wave pigment system (above 680 nm) can be explained by the non-linearity mentioned above, not suggesting a participation of PSI in the generation of this afterglow.     

Cytological diagnosis of lung cancer and precancer using the principal rules]

Analysis of clinical and morphological findings in 306 patients making use of a complex of modern methods at tissue, cellular, and subcellular levels enabled the authors to define the early precancer changes in the bronchial epithelium. The diagnostic value of precancer changes in the lungs and lung cancer was assessed by successive statistical analysis and mathematical estimations. Medical mathematical decisive rules have been developed and are proposed for practical use, which permit the diagnosis of precancer and cancer of the lungs with a high degree of reliability (87 and 89%, respectively).     

Features of the antiviral effect of carbocyclic compounds depending on their concentration

As there are no studies done on the prevalence of intestinal parasites in Lebanon since 1967, this study was undertaken to reveal the current patterns of intestinal parasitic infestations in Lebanese patients from two geographic regions: Beirut and Tripoli. Analysis was based on 33,253 stool specimens examined at the American University of Beirut Medical Center (AUH) and 11,611 specimens examined at the Islamic Hospital (IH) in Tripoli over five and three years, respectively. The prevalence of intestinal parasites at AUH and IH were 8.47% and 45.35%, respectively (overall 18%). The prevalence in males vs females was almost the same; being 8.23% vs 8.74%, and 44.67% vs 45.88%, at AUH and IH, respectively. Multiple infections were noted in 8.8% and 3.5% of stool specimens at AUH and IH, respectively. Although 18 different types of parasites were encountered, the most common pathogenic parasites found at AUH vs IH were: Giardia lamblia (20.7% vs 10.5% of parasites found), Entamoeba histolytica (19.41% vs 1.25%), Taenia spp. (6.03% vs 4.08%) and Ascaris lumbricoides (2.09% vs 46.97%). The overall yearly or monthly prevalence of parasites recovered from both hospitals did not show clear seasonal patterns. Compared to developed countries, Lebanon still suffers from a high prevalence and a wide spectrum of intestinal parasites.     

Dentists, pills and pregnancies

Unplanned pregnancies may occur if antibiotics are prescribed to women using the combined oral contraceptive pill. To investigate awareness of the potential for this interaction among general dental practitioners, the authors designed a cross-sectional questionnaire based study and sent it out to a random sample of GDPs in Scotland.     

A comparative study of carboxylesterase in the white mouse and in the caterpillar of the cotton bollworm Heliothes armigera

Studies have been made on enzymic hydrolysis of p-nitrophenylacetate (p-NPhAc), n-nitrophenylbutyrate (p-NPhBu) and indophenylacetate (IPhAc) by carboxylesterase (CE) from mouse blood plasma and liver as well as from caterpillar of the cotton worm haemolymph, intestine and fat body. Different KM and V max values were obtained for CE from these sources. The highest specific activity of CE from mouse liver and caterpillar intestine and fat body was observed with p-NPhBu. p-NPhAc is the best substrate for CE from mouse blood serum and caterpillar haemolymph. Carboxylesterases from mouse and caterpillar differed in their sensitivity to armine and paraoxone by 1-2 orders depending on the substrate used. Species and tissue differences in the kinetics of CE-catalyzed reactions with different substrates and inhibitors were revealed.