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We present a significantly improved set of complex indices of refraction (optical constants) for crystalline (NH(4))(2)SO(4) at 298 K, determined from extinction spectra measured in an aerosol flow tube (AFT). The improved values provide more accurate reproductions of experimental extinction spectra when used in light scattering calculations (Mie, T-matrix, etc.). Optical constants were also derived from measurements using a cryogenic AFT at 243, 223, and 213 K, temperatures characteristic of the upper troposphere and stratosphere. Only minor changes in the optical constants were observed down to 223 K, the transition temperature to the ferroelectric phase, after which significant changes were observed. Here we report the first complex indices of refraction at reduced temperatures for both phases of crystalline (NH(4))(2)SO(4).

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Complex refractive indices of supercooled liquid water at 240, 253, 263, and 273 K, and ice at 200, 210, and 235 K in the mid infrared from 460 to 4000 cm(-1) are reported. The results were obtained from the extinction spectra of small (micron-size) aerosol particles, recorded using the cryogenic flow tube technique. An improved iterative procedure for retrieving complex refractive indices from extinction measurements is described. The refractive indices of ice determined in the present study are in good agreement with data reported earlier. The temperature region and range of states covered in the present work are relevant to the study of upper tropospheric and stratospheric aerosols and clouds.

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The authors describe the design and implementation of a large multiethnic cohort established to study diet and cancer in the United States. They detail the source of the subjects, sample size, questionnaire development, pilot work, and approaches to future analyses. The cohort consists of 215,251 adult men and women (age 45-75 years at baseline) living in Hawaii and in California (primarily Los Angeles County) with the following ethnic distribution: African-American (16.3%), Latino (22.0%), Japanese-American (26.4%), Native Hawaiian (6.5%), White (22.9%), and other ancestry (5.8%). From 1993 to 1996, participants entered the cohort by completing a 26-page, self-administered mail questionnaire that elicited a quantitative food frequency history, along with demographic and other information. Response rates ranged from 20% in Latinos to 49% in Japanese-Americans. As expected, both within and among ethnic groups, the questionnaire data show substantial variations in dietary intakes (nutrients as well as foods) and in the distributions of non-dietary risk factors (including smoking, alcohol consumption, obesity, and physical activity). When compared with corresponding ethnic-specific cancer incidence rates, the findings provide tentative support for several current dietary hypotheses. As sufficient numbers of cancer cases are identified through surveillance of the cohort, dietary and other hypotheses will be tested in prospective analyses.

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The performance of the dietary questionnaire used in a multiethnic cohort study in Hawaii and Los Angeles was assessed in a calibration substudy that compared diet reported from the questionnaire with three 24-hour dietary recalls. For the calibration substudy, subjects from each of eight subgroups defined by sex and ethnic group (African-American, Japanese-American, Latino, and White) were chosen randomly from among the cohort members, and each participant's previous day's diet was assessed by telephone recall on three occasions over approximately 2 months. After completing the three 24-hour recalls, each calibration subject was sent a second questionnaire; 1,606 persons completed three recalls and a second questionnaire (127 to 267 per ethnic-sex group). This report describes correlation coefficients and calibration slopes for the relation between the 24-hour recalls and second questionnaire values for a selected set of macro- and micronutrients, as absolute intakes, nutrient densities, and calorie-adjusted nutrients. In all subgroups, estimates of the correlation between the questionnaire and 24-hour recalls were greater after energy adjustment (average correlations ranged from 0.57-0.74 for nutrient densities and from 0.55-0.74 for calorie-adjusted nutrients) than when absolute nutrient values were used (average range 0.26-0.57). For absolute nutrient intakes, the correlations were greatest for Whites, somewhat lower for Japanese-Americans and Latinos, and lowest for African-Americans. After energy adjustment, the difference between subgroups were diminished, and the correlations were generally highly satisfactory.

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The absorption of the model drug carbenoxolone was reevaluated using an in situ rat intestinal perfusion technique in which disappearance from the intestinal lumen, binding to the perfused jejunal segment, and appearance in the mesenteric (jejunal) vein were measured. The effect of the degree of ionization on these processes was examined by employing perfusion solutions of pH 4.0, 4.4, 5.0, and 6.5. Tissue binding was observed to be independent of pH. There was a rank-order correlation of the transfer rate of carbenoxolone with the degree of ionization which indicated that carbenoxolone was absorbed faster in its ionized form. This observation is in direct opposition to the pH-partition hypothesis, a finding which appears to support the previous work of Bridges et al. Ion-pairing of carbenoxolone with sodium ion present in the pH 6.5 buffer is one possible explanation for the unusually high transfer rate seen at this pH. A more likely explanation is that at the low pH values, some carbenoxolone precipitated out of solution during the perfusion experiments, thereby reducing the driving force for diffusion across the intestinal wall.

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The inconclusive findings of past analytic epidemiologic studies on diet and breast cancer may have resulted from the inability of these studies to assess early dietary exposures. The role of macronutrient intake during early life can be indirectly studied, however, by examining past and present body size. The authors identified by computer linkage a population-based historical cohort of 38,084 women born between 1918 and 1943, on whom information about weight and height had been recorded in Hawaii in both 1942-1943 and 1972. Linkage of this cohort to the Hawaii Tumor Registry resulted in the identification of 607 incident cases of breast cancer for 1972-1983. An average of 4.4 cancer-free controls were matched to each case on year and month of birth and race of the parents. A matched case-control analysis, conducted in each five-year birth cohort, revealed a negative association of adolescent body mass to premenopausal breast cancer. This negative association was statistically significant in girls aged 10-14 years in 1942 (p for trend, 0.004), was present in all ethnic groups, and was strongest among overweight young women who remained overweight in adulthood. Early-age weight, height, and body surface area were not associated with either pre- or postmenopausal breast cancer. Adult weight and gain in body mass since 1942 were positively associated with postmenopausal breast cancer risk. Adjustment for age at first birth, parity and socioeconomic indicators for 1942 and 1972 did not modify the results. This study provides evidence for a protective role of adolescent obesity against premenopausal breast cancer, and for an enhancing role of a positive energy balance during adult life on postmenopausal breast cancer.

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There is evidence for more than one alpha 1 acid glycoprotein (alpha 1 AGP) gene, and they all appear to be in close proximity. In situ hybridization of the cloned human cDNA p alpha 1AGP-2 to human chromosomes indicates that the alpha 1AGP genes are located between bands q31 and q34.1 on chromosome 9. This finding is in agreement with the previous assignment of the locus for alpha 1AGP to a linkage group with ABO and AK on chromosome 9.

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The hypnotic triazolam (TZ), a triazolobenzodiazepine displays a short physiological half life and has been used for the treatment of insomnia related to anxiety states. Our major objectives were the direct measurement of the temperature dependence and the gamma-aminobutyric acid (GABA) effect of [3H]TZ binding in the rat brain. Saturation studies showed a shift to lower affinity with increasing temperatures (Kd = 0.27 +/- 08 nM at 0 degree C; Kd = 1.96 +/- 0.85 nM at 37 degrees C) while the Bmax values remained unchanged (1220 +/- 176 fmoles/mg protein at 0 degree C and 1160 +/- 383 fmoles/mg protein at 37 degrees C). Saturation studies of [3H]TZ binding in the presence or absence of GABA (100 microM) showed a GABA-shift. At 0 degrees C the Kd values were (Kd = 0.24 +/- 0.03 nM/-GABA; Kd = 0.16 +/- 0.04/+GABA) and at 37 degrees C the Kd values were (Kd = 1.84 +/- 0.44 nM/-GABA; Kd = 0.95 +/- 0.29 nM/+GABA). In contrast to reported literature, our findings show that TZ interacts with benzodiazepine receptors with a temperature dependence and GABA-shift consistent with predicted behavior for benzodiazepine agonists.

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