A comparative analysis of teenagers who smoke different cigarette brands.

This study analyzed and compared the survey responses of teenagers who smoke different cigarette brands. It was found that teen Marlboro and Camel smokers perceived themselves as having more stress in their lives as compared with teen Newport smokers. On average, Marlboro smokers were depressed or sad more often than were Camel or Newport smokers. Camel smokers were generally less interested in a peer stop-smoking program than were Newport or Marlboro smokers. Finally, these teen smokers, regardless of cigarette brand, had similar opinions about quitting. Given the differences across brands, more flexible approaches may be needed to address teenage smoking.

Bicarbonate binding activity of the CmpA protein of the cyanobacterium Synechococcus sp. strain PCC 7942 involved in active transport of bicarbonate.

The cmpABCD operon of the cyanobacterium Synechococcus sp. strain PCC 7942 encodes an ATP-binding cassette transporter involved in HCO(3)(-) uptake. The three genes, cmpBCD, encode membrane components of an ATP-binding cassette transporter, whereas cmpA encodes a 42-kDa cytoplasmic membrane protein, which is 46.5% identical to the membrane-anchored substrate-binding protein of the nitrate/nitrite transporter. Equilibrium dialysis analysis using H(14)CO(3)(-) showed that a truncated CmpA protein lacking the N-terminal 31 amino acids, expressed in Escherichia coli cells as a histidine-tagged soluble protein, specifically binds inorganic carbon (CO(2) or HCO(3)(-)). The addition of the recombinant CmpA protein to a buffer caused a decrease in the concentration of dissolved CO(2) because of the binding of inorganic carbon to the protein. The decrease in CO(2) concentration was accelerated by the addition of carbonic anhydrase, indicating that HCO(3)(-), but not CO(2), binds to the protein. Mass spectrometric measurements of the amounts of unbound and bound HCO(3)(-) in CmpA solutions containing low concentrations of inorganic carbon revealed that CmpA binds HCO(3)(-) with high affinity (K(d) = 5 microm). A similar dissociation constant was obtained by analysis of the competitive inhibition of the CmpA protein on the carboxylation of phosphoenolpyruvate by phosphoenolpyruvate carboxylase at limiting concentrations of HCO(3)(-). These findings showed that the cmpA gene encodes the substrate-binding protein of the HCO(3)(-) transporter.

Pathological changes of xanthinurolithiasis in calves.

Pathological examination was carried out on a male and a female beef calf 3 months old involved in an outbreak of xanthinurolithiasis. This outbreak has been found among indigenous Japanese Black calves in an area of the Kyushu region since 1971. Involved in it, calves were retarded in growth, with the back curved, exhibiting depression and anorexia. A characteristic gross change was the accumulation of yellowish white or yellowish brown sand-grain-like calculi in the urinary passage. Histologically, a number of calculi, as birefractive crystals, were contained mainly in the collecting and distal uriniferous tubules in the renal medulla. In the uriniferous tubules epithelial cells surrounding those crystals presented such reaction as to form syncytia, and the surrounding connective tissue proliferated. Biochemical examination revealed that the calculi were composed of xanthine.

Identification of hemagglutinin and neuraminidase genes of influenza B virus.

The genome of influenza B viruses was shown by electrophoresis to consist of eight RNA segments. The fifth largest segment coded for hemagglutinin and the sixth coded for neuraminidase.