Carbon-isotope discrimination by leaves of Flaveria species exhibiting different amounts of C3-and C 4-cycle co-function.

Carbon-isotope ratios were examined as δ(13)C values in several C3, C4, and C3-C4 Flaveria species, and compared to predicted δ(13)C, values generated from theoretical models. The measured δ(13)C values were within 4‰ of those predicted from the models. The models were used to identify factors that contribute to C3-like δ(13)C values in C3-C4 species that exhibit considerable C4-cycle activity.

A second follow-up of mortality in a cohort of pesticide applicators.

A cohort of 16,124 male pesticide applicators was matched with Social Security Administration and National Death Index (NDI) files through December 31, 1984. In all, 1,082 deaths were ascertained, and death certificates were obtained for 994 (92%). The standardized mortality ratio (SMR) for all causes of death was 98.

Radioactive iodine therapy and breast cancer. A follow-up study of hyperthyroid women.

A follow-up study of 1,762 hyperthyroid women who were treated at the Massachusetts General Hospital Thyroid Unit between 1946 and 1964 was conducted. The average length of follow-up was 17.2 years.

Incidence of depression and anxiety: the Stirling County Study.

Prevalence studies in psychiatric epidemiology out-number incidence investigations by a wide margin. This report gives descriptive information about the incidence of depression and anxiety disorders in a general population. Using data gathered in a 16-year follow-up of an adult sample selected as part of the Stirling County Study (Canada), the incidence of these types of disorders was found to be approximately nine cases per 1,000 persons per year.

Adverse outcomes of pregnancy in women exposed to diethylstilbestrol in utero.

We analyzed data collected by interview and medical record review for 200 women exposed to diethylstilbestrol (DES) and 12,240 unexposed women to evaluate the relation between maternal DES exposure and outcomes of pregnancy. Low birth weight, short gestation, bleeding in the first trimester, toxemia, breech presentation and premature rupture of the membranes occurred more often among the exposed women. These relationships remained statistically significant after the use of linear regression and logistic regression analyses to control for multiple confounding factors.

Associations between enzyme genotypes and dark respiration in perennial ryegrass, Lolium perenne L.

In this study, we determined whether relationships existed between dark respiration and genotype at five enzyme polymorphisms in perennial ryegrass, Lolium perenne L. Positive correlations were found between Q of dark respiration and genotype at the phosphoglucomutase (PGM) and 6-phosphogluconate dehydrogenase (6PGD) loci. Plants doubly homozygous for the common allele at these loci were found to have Q values 20% higher than those for double heterozygotes.

Photosynthesis in Flaveria brownii A.M. Powell : A C(4)-Like C(3)-C(4) Intermediate.

Leaves of Flaveria brownii exhibited slightly higher amounts of oxygen inhibition of photosynthesis than the C(4) species, Flaveria trinervia, but considerably less than the C(3) species, Flaveria cronquistii. The photosynthetic responses to intercellular CO(2), light and leaf temperature were much more C(4)-like than C(3)-like, although 21% oxygen inhibited the photosynthetic rate, depending on conditions, up to 17% of the photosynthesis rate observed in 2% O(2). The quantum yield for CO(2) uptake in F.

Relative and absolute excess risks of coronary heart disease among women who smoke cigarettes.

We prospectively examined the incidence of coronary heart disease in relation to cigarette smoking in a cohort of 119,404 female nurses who were 30 to 55 years of age in 1976 and were free of diagnosed coronary disease. During six years of follow-up, 65 of the women died of fatal coronary heart disease and 242 had a nonfatal myocardial infarction. The number of cigarettes smoked per day was positively associated with the risk of fatal coronary heart disease (relative risk = 5.

1-Desamino-8-D-arginine vasopressin (desmopressin) decreases operative blood loss in patients having Harrington rod spinal fusion surgery. A randomized, double-blinded, controlled trial.

To evaluate the effect of 1-desamino-8-D-arginine vasopressin (desmopressin) on blood loss in surgery, we conducted a randomized, double-blind trial of the drug in 35 patients with normal hemostatic function who were having spinal fusion with Harrington rod instrumentation. Seventeen patients were designated to receive 10 micrograms/m2 of desmopressin, and 18, to receive a placebo. Preoperative testing showed that desmopressin increased factor VIII coagulant activity, von Willebrand antigen concentrations, glass bead platelet retention, and prothrombin consumption and decreased the partial thromboplastin and bleeding times (p less than or equal to 0.

Risk factors accounting for racial differences in the rate of premature birth.

In a hospital-based cohort of 8903 black and white women, we investigated medical and socioeconomic risk factors that may explain the known increase in premature births among black women. Among the medical conditions examined, only the maternal hematocrit level (or some related factor) explained a substantial proportion (60 percent) of the increased rate of premature births to black women. Four economic, demographic, and behavioral predictors of prematurity were also examined: age less than 20 years, single marital status, receiving welfare support, and not having graduated from high school.

Affective disorders and mortality. A general population study.

A 16-year prospective study of a general population sample indicates that those who had reported a depression and/or anxiety disorder at baseline experienced 1.5 times the number of deaths expected on the basis of rates for a large reference population. As part of the Stirling County Study (Canada), the information was gathered from 1003 adults through structured interviews and was analyzed by means of a diagnostic computer program.

Cancer mortality after multiple fluoroscopic examinations of the chest.

Total cancer deaths were not increased among 2,074 women and 1,277 men who were fluoroscopically examined an average of 73 and 91 times, respectively, during lung-collapse therapy for tuberculosis (TB). Patients who did not receive this form of therapy (2,141 women and 1,418 men) and general population rates were used for comparison. All subjects were discharged alive from eight TB sanatoria in Massachusetts between 1930 and 1954; the average follow-up was 23 years.

Acquired spondylolysis after posterolateral spinal fusion.

A case of spondylolysis occurring immediately above a posterolateral lumbar spinal fusion in a 12-year-old girl is described. This case illustrates a potential problem of stress concentration at the pars interarticularis, previously only described after posterior interlaminar fusion.

Field measurements of photosynthesis, water-use efficiency, and growth inAgropyron smithii (C) andBouteloua gracilis (C) in the Colorado shortgrass steppe.

Field measurements of gas exchange and growth were conducted on a C grass,Agropyron smithii, and a C grass,Bouteloua gracilis, in order to further establish the adaptive significance of the C pathway under natural conditions. Maximum rates of leaf area expansion in tillers and maximum seasonal photosynthesis rates of both species occurred during the cool, early summer month of June. The occurrence of maximum growth and photosynthesis inB.

Co-function of C3-and C 4-photosynthetic pathways in C3, C 4 and C 3-C 4 intermediate Flaveria species.

The potential for C4 photosynthesis was investigated in five C3-C4 intermediate species, one C3 species, and one C4 species in the genus Flaveria, using (14)CO2 pulse-(12)CO2 chase techniques and quantum-yield measurements. All five intermediate species were capable of incorporating (14)CO2 into the C4 acids malate and aspartate, following an 8-s pulse. The proportion of (14)C label in these C4 products ranged from 50-55% to 20-26% in the C3-C4 intermediates F.

Observations on the healthy worker effect.

Follow-up mortality data from ten groups of employed persons are compared to the mortality rates of the United States general population. Comparisons related to the healthy worker effect (HWE) are computed. As measured by a relative comparison, the standardized mortality ratio (SMR), the HWE is seen to have a dynamic phase and a plateau phase in relation to length of follow-up.

Psychiatric consultation in somatization disorder. A randomized controlled study.

The per capita expenditure for health care of patients with multiple physical symptoms but no apparent physical disease (somatization disorder) is up to nine times the average per capita amount. We conducted a randomized controlled trial to determine whether psychiatric consultation would reduce the medical costs of these patients, without effecting a substantial change in patient outcome. Thirty-eight patients were randomly assigned to treatment or control groups and studied prospectively for 18 months.

Diagnosis and outcome: depression and anxiety in a general population.

An assessment of the long-term outcome for depression and anxiety disorders in a general population was made as part of the Stirling County Study. Measuring outcome as a dichotomy between experiencing recurrent episodes or not during a 17-year cohort interval, it was found that 56% of the 'cases' had a poor prognosis. While sex, age and level of severity were not significantly related to outcome, an initial diagnosis of depression was predictive of unfavourable prognosis.

Patients with multiple unexplained symptoms. Their characteristics, functional health, and health care utilization.

To define groups of patients with inappropriately high health care utilization better, we have studied a group of 41 chronically ill patients to determine their characteristics, symptoms, functional health status, and amount of health care utilization. This group had somatization disorder diagnosed by specific criteria. They can be easily recognized by primary care physicians by their multiple complaints, negative physical examination results, and a history of multiple medical examinations.

Midday depression in net photosynthesis and stomatal conductance in Yucca glauca : Relative contributions of leaf temperature and leaf-to-air water vapor concentration difference.

Yucca glauca in the Colorado shortgrass prairie undergoes a pronounced midday depression in net photosynthesis and stomatal conductance under summer field conditions. This phenomenon can be duplicated in the laboratory using potted plants by simulating a typical summer daily pattern of leaf temperature and leaf-to-air water vapor concentration difference (Δw). The decrease in photosynthetic rate appears to be due primarily to high leaf temperatures, while the decrease in stomatal conductance can be attributed mainly to high Δw values.

Epidemiology of neonatal hyperbilirubinemia.

Interview and record review data from 12,023 singleton deliveries were analyzed to determine the relationships between neonatal hyperbilirubinemia (10 mg/dL or greater) and maternal characteristics. Confounding variables were controlled by multiple logistic regression analysis. There was a statistically significant positive relationship between hyperbilirubinemia and low birth weight, Oriental race, premature rupture of membranes, breast-feeding, neonatal infection, use of the "pill" at time of conception, instrumental delivery, and history of first trimester bleeding.

Mortality among rubber workers: IX. Curing workers.

This research examined mortality among 1,152 white male production workers employed in the tire-curing department of a large rubber manufacturing plant. To determine whether these men had any cause-specific mortality excesses, their experience was compared with that of both the U.S.

Mortality among rubber workers: X. Reclaim workers.

This study evaluated the mortality experience of 1,352 white and 438 nonwhite men who worked in the rubber-reclaiming division of a large rubber manufacturing company. In comparisons of mortality of white reclaim workers with that of nonreclaim workers rate ratios were 2.7 for esophageal cancer (six observed deaths among reclaim workers), 2.