Cotinine was measured in the serum, saliva, and urine of nonsmokers, passive smokers, and active smokers. Serum and saliva could not discriminate between nonsmokers and passive smokers. Mean urine cotinine was higher in passive smokers than nonsmokers but there was a great deal of intersubject overlap. Cotinine in all body fluids could separate active smokers from the other two groups. Among smokers, light smokers had lower levels than heavier smokers. (Am J Public Health 1988; 78:699-701.)

Erratum: High resolution S 1←S 0 fluorescence excitation spectra of hydroquinone: Distinguishing the cis and trans rotamers by their nuclear spin statistical weights [J.High resolution S 1←S 0 fluorescence excitation spectra of hydroquinone. Distinguishing the cis and trans rotamers by their nuclear spin statistical weights Highresolution one and two photon excitation spectra of t r a n s, t r a n s1,3,5,7octatetraeneBoth fluorescence excitation and dispersed emission techniques have been used to study the SI +-So electronic spectra of 1-and 2-hydroxynaphthalene (1/2HN) in the collision-free environments of a supersonic jet and a twice-skimmed molecular beam, using both pulsed and high-resolution cw lasers operating in the ultraviolet. In the jet experiments, we observe that each molecule exhibits two electronic origins, separated by 274 cm -1 in 1HN and by 317 cm -I in 2HN. In the beam experiments, we resolve the rotational structure of each of the four bands and determine the inertial constants of all eight zero-point vibrational levels, accurate to ± 0.1 MHz. We also determine the .orientations of the four optical transition moments in the molecular frame. Significant differences in both the inertial constants and the transition moment orientations are observed in each band. Similar experiments have been performed on the hydroxy-deuterated 1/2HN (l/2DN). A comparison of the results obtained for 1/2DN with those for the corresponding bands in 1/ 2HN makes possible the determination of the center-of-mass coordinates of the hydroxy hydrogen in both electronic states, accurate to ± 0.02 A. Differences in these coordinates reveal that the two electronic origins in each spectrum are caused by the presence of two N--O-H(D) rotamers in both 1H(D)N and 2H(D)N, one with a cis (or syn) geometry and one with a trans (or anti) geometry with respect to the naphthalene frame. We make an unambiguous assignment of each origin to a specific rotamer. The lower energy origin in the spectrum of 1HN is that of the cis rotamer, whereas the lower energy origin in the spectrum of 2HN is that of the trans rotamer. We then use these results, together with those of ab initio calculations on the ground electronic states of all four isomers, to explore the reasons for the differences in their energies, to account for the orientations of their transition moments, and to specify other features of the So and SI potential energy surfaces along the cis-trans isomerization coordinate. Motion along this coordinate requires significant displacement of the oxygen atom and selected ring hydrogens as well as rotation about the c-o bond, in both electronic states.

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Background: Autosomal Recessive Polycystic Kidney Disease (ARPKD) is marked by cyst formation in the renal tubules, primarily in the collecting duct (CD) system, ultimately leading to end-stage renal disease. Patients with PKD are generally advised to restrict their dietary sodium intake. This study was aimed at testing the outcomes of dietary salt manipulation in ARPKD. Methods: PCK/CrljCrlPkhd1pck/CRL (PCK) rats, a model of ARPKD, were fed a normal (0.4% NaCl; NS), high salt (4% NaCl; HS), and sodium-deficient (0.01% NaCl; SD) diets for 8 weeks. Immunohistochemistry, GFR measurements, balance studies, and molecular biology approaches were applied to evaluate the outcomes of the protocol. Renin-angiotensin-aldosterone system (RAAS) levels were assessed using LC-MS/MS, and renal miRNA profiles were studied. Findings: Both HS and SD diets resulted in an increase in cystogenesis. However, SD diet caused extensive growth of cysts in the renal cortical area, and hypertrophy of the tissue; RAAS components were enhanced in the SD group. We observed a reduction in epithelial Na + channel (ENaC) expression in the SD group, accompanied with mRNA level increase. miRNA assay revealed that renal miR-9a-5p level was augmented in the SD group; we showed that this miRNA decreases ENaC channel number in CD cells. Interpretation: Our data demonstrate a mechanism of ARPKD progression during salt restriction that involves activity of ENaC. We further show that miR-9a-5p potentially implicated in this mechanism and that miR-9a-5p downregulates ENaC in cultured CD cells. Our findings open new therapeutic possibilities and highlight the importance of understanding salt reabsorption in ARPKD.

Cadmium injections during molar tooth development in the rat were strongly caries-promoting in female rats. Cadmium also partially negated the cariostatic effect of fluoridated drinking water in both male and female rats. The mechanism for the caries-promoting properties of cadmium is unknown, but may be related to cadmium uptake into enamel and dentin. Cadmium was taken up into molar enamel and dentin in proportion to the amount of cadmium administered, but cadmium did not influence uptake of fluoride onto eruted enamel. Calcium and ash concentrations in molar enamel were not altered by cadmium administration.