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Background Vital statistics data were used to describe the burden of cancer in Texas. Methods Average annual age-adjusted mortality data in Texas (1986 to 1990) for 17 cancer types were compared with the US data for whites and blacks and with California data for Hispanics. Trends were examined from 1980 to 1990 for the entire state and from 1976 to 1989 for 24 geographic regions within the state. Results Mortality excesses were detected for lung and liver cancer, and deficits for colorectal, breast, and prostate cancers. Rates were generally stable from 1980 to 1990 with several exceptions (lung, liver, colon). Six areas of Texas, including four areas along the Gulf Coast, had relatively more excesses of various cancers, without a discernible pattern by cancer type. Conclusions Overall, Texas has fared favorably in cancer mortality when compared with the United States. Enhanced evaluation of the frequency of cancer, as well as the conduct of etiologic research, must await the availability of statewide long-term cancer incidence data.

Context: Numerous randomized controlled trials have demonstrated limited efficacy of intrapartum fetal heart rate monitoring in improving fetal outcome. A potential reason is the wide variability in clinical decision making seen with its use. Standardizing management of variant intrapartum fetal heart rate tracings may reduce this variability and lead to improvement in fetal outcome. Objective: We sought to develop notification guidelines and a management algorithm for variant intrapartum fetal heart rate tracings that improve fetal outcome and do not increase the operative delivery rate. Design: Outcomes for cases involving the use of our notification guidelines and management algorithm over six months (1181 deliveries) were compared with outcomes for historical control subjects (2247 deliveries). Main outcome measures: The main outcome measures were Apgar scores

An autopsy study was conducted to investigate whether there is transplacental transfer of asbestos in humans. The asbestos burden of lung, liver, skeletal muscle, and placenta digests of 40 stillborn infants was determined using a bleach digestion method. The fibers detected in the tissue digests were characterized as to the type of asbestos, using electron microscopy, energy-dispersive x-ray analysis, and selected-area diffraction analysis. Placental digests of 45 full-term, liveborn infants were similarly processed as controls. Low levels of small, thin, uncoated asbestos fibers were detected in the placentas and organs of 37.5% of the stillborn infants (15 of 40). The fiber sizes ranged from 0.05 to 5.0 microns in length and 0.03 to 0.3 micron in width, with a mean length of 1.15 microns and a mean width of 0.069 micron. Maximum numbers of fibers were found in the lungs (mean 235,400 fibers/g; n = 10), followed by liver (mean 212,833 fibers/g; n = 6), placenta (mean 164,500 fibers/g; n = 4), and skeletal muscle (80,000 fibers/g; n = 1). The fibers were detected at all stages of gestation and showed no association with gestational age. A significant association was found between fiber presence and working mothers, and positive but nonsignificant associations were found with maternal history of drug abuse, previous abortions, and fetal maceration. No association was found between premature rupture of membranes and fiber presence. No fibers were detected in the 45 placentas of the liveborn control infants. There was a highly significant difference in the asbestos fiber counts of the placentas of the stillborn and liveborn infants (P.001). Our studies demonstrate the presence of short and thin asbestos fibers in stillborn infants and their positive association with working mothers.

OBJECTIVE To investigate fetal-placental cocaine clearance, and to determine the fetal catecholamine and cardiovascular responses to continuous intravenous cocaine infusion in fetal sheep. METHODS Eleven pregnant ewes and their fetuses (127 +/- 2 days' gestation; term 150 days) were chronically instrumented. Fetuses received intravenous cocaine at 0.05, 0.1, or 0.2 mg/kg/minute. Fetal cardiovascular and hematologic measurements were made before and serially for 90 minutes after initiation of the cocaine infusion. RESULTS Steady-state fetal plasma cocaine concentrations were observed by 15 minutes of infusion and averaged 136 +/- 11, 318 +/- 65, and 610 +/- 36 ng/mL, respectively, at each dose. Fetal-placental cocaine clearance rate was independent of dose (337 +/- 39 mL/kg/minute), indicating that it is a first-order pharmacokinetic process. Fetal plasma concentration of benzoylecgonine, a principle cocaine metabolite, increased throughout the study to approximately 25% above cocaine levels by 90 minutes. There were significant increases in fetal heart rate (from 169 +/- 11 to 242 +/- 36 beats per minute), mean blood pressure (from 53 +/- 4 to 63 +/- 5 mmHg), and systolic blood pressure (from 68 +/- 2 to 80 +/- 5 mmHg), with a corresponding increase in catecholamine levels seen in the fetuses infused with 0.2 mg/kg/minute. These changes were not seen in the fetuses given lower doses of cocaine. CONCLUSION Fetal-placental clearance of cocaine is a rapid, first-order pharmacokinetic process. During prolonged cocaine exposure, plasma benzoylecgonine concentrations accumulate significantly. Significant catecholamine and cardiovascular changes are seen in fetal sheep with a continuous infusion of cocaine at 0.2 mg/kg/minute or greater.

Follow-up on two reports of an excess of keratoses among paraquat production workers was conducted to evaluate the contribution of occupational exposures to the prevalence of keratoses among workers in a paraquat production plant in Texas. A cross-sectional study design was used to compare the prevalence of keratoses among current workers to an age, race, and sex frequency-matched group of their friends who had never worked at the plant. The analysis is based on 112 workers and 232 friends. Exposure, outcome, and covariables used in the analyses were obtained from an interview questionnaire, dermatology exam, and company records. Overall, the prevalence proportion of the presence of any actinic keratoses among workers and friends was similar (0.30 and 0.28, respectively). Among high cumulative exposed workers, the prevalence of any actinic keratoses was 0.40 compared to 0.20 among low-exposed workers and 0.28 among friends. These results were further explored using a multiple logistic regression approach to adjust for known risk and possibly confounding variables. Statistically significant high risks of actinic keratoses were demonstrated for freckling before age 16 years, older age, suntanning behaviors, occupational exposure to polycyclic aromatic hydrocarbons (PAH), and Fitzpatrick skin type. There was no significant contribution of overall exposure status (worker vs. friend). Similar to the crude analysis, the odds of actinic keratoses of high-exposed workers compared to friends was 1.9 (confidence interval [CI] = 0.9-4.2) whereas the comparable odds ratio for low-exposed workers vs. friends was 0.6 (CI = 0.2–1.7). These data do not demonstrate an excess of actinic keratoses overall nor any consistent increase in the odds of keratoses with an increase in plant exposure level. © 1994 Wiley-Liss, Inc.

The pattern of change in plasma total cholesterol (TC) and blood pressure(SBP and DBP) over time and their relations to anthropometric measurements were observed longitudinally. In 40 infants who were seen at a pediatric clinic in The Woodlands, Texas, TC (by the Reflotron), SBP, DBP (by the Dinamap), weight and body length were measured at ages 0.5, 2, 4, 6, 9 and 12 months. For TC, in males, the greatest increment in median values, from 114 to 134 mg/dl, occurred between ages 0.5 and 2.0 months. For females, the greatest increment in TC, from 131 to 141 mg/dl, occurred between ages 9 and 12 months. There were strong tracking correlations between paired TC measurements taken as early as age 0.5 months with later measurements. These correlations were stronger and more often significant for males than for females. The associations of body measurements with TC were modest at most, and somewhat stronger for females than for males. Infants who received breast milk had mean TC values 47 mg/dl higher than infants receiving formula only during the period of breast feeding. This difference disappeared by age 12 months. For both SBP and DBP, for males and females togather, the greatest increment (10 mmHg) occurred between ages 0.5 and 2.0 months. DBP continued to increase to age 4 months. Tracking correlations of SBP and DBP were generallyweak and not significant for either gender. The correlations between DBP, but not SBP, and body measurements were significant only for females at age 12 months. Maternal history of CVD risk factors was significantly related to SBP in females but not males. For DBP, neither maternal nor paternal history was related. This study further documents changes in TC and blood pressure measurements during infancy with gender differences in behavior of these measurements at this early age.

This study describes the relationship between the user cost of capital and capital budgeting processes and presents a formula for computing the user cost of an investment, accommodating the existence of taxes, inflation, and a nonconstant level of production. A project acceptability criterion assigning positive net present value when cash operating income exceeds user cost is discussed and applied to several examples. The test is shown to be useful and easy to apply.

Most studies employing the user cost of capital are inconsistent because their user cost assumes capital has an infinite life and depreciates geometrically, whereas they employ capital stock estimates that assume finite life and nongeometric depreciation. This study examines the significance of the inconsistency and derives a user cost formula that eliminates it.

The sorption of eight organic compounds by a representative green alga, Selenastrum capricornutum , was determined by gas-liquid chromatography using a series of linear model experiments. The log 10 bioconcentration factors (BCF), defined as the ratio of the concentration on in the algae to the concentration in the aqueous medium, are as follows: benzene, 3.32; toluene, 3.18; chlorobenzene, 3.69; 1,2-dichlorobenzene, 4.17; naphthalene, 4.10; phenanthrene, 4.38; di- n -butylphthalate, 4.36 and pyrene, 4.56. The relation of log 10 BCF correlation with log 10 octanol-water partition coefficient was determined as log 10 BCF = 0.46 log 10 P + 2.36.

Windfall profits and losses accrue to investors only when expected after-tax returns or discount rates change, and major tax policy shifts are likely to alter these variables. This study introduces a cashflow valuation model for estimating the windfalls to owners of U.S. nonfinancial corporations caused by the enactment of tax changes. The model is illustrated by analysis of two reform packages, the Treasury Proposal of November 1984 and the Tax Reform Act of 1986. We find that the original Treasury plan would have boosted stock prices by 20 to 30 percent; an increase of 10 to 12 percent is computed for the Tax Reform Act of 1986. This anomalous result -- a $125 to $140 billion dollar corporate tax increase (over five years) raising stock prices -- occurs because the tax increase is on new capital, not old capital. The stock market largely values expected returns on the existing capital stock, and these returns benefit from the adverse treatment of new investment.

Several studies of styrene-butadiene rubber (SBR) workers have reported excess cancers at various sites; however, little could be concluded concerning specific etiologic agents because of the multiple exposures encountered by these groups. The current study examined cause-specific mortality in a cohort of 2,586 male workers employed for at least 6 months between 1943 and 1979 in a butadiene manufacturing plant that supplied butadiene to two SBR plants. Standardized mortality ratios were calculated using national (NSMR) and local (LSMR) comparison populations. The all-cause NSMR was 80 (p less than 0.05) and the all-cancer NSMR was 84; the corresponding LSMRs were 96 and 76 (p less than 0.05). No significant excesses were observed for any cause of death except lymphosarcoma and reticulum cell sarcoma (NSMR = 235). When the cohort was subdivided into routine, nonroutine, and low-exposure groups, the SMRs were consistently elevated for this cause of death in all three groups. However, direct comparisons between each of the two exposure groups and the low-exposure group were inconsistent. This suggests butadiene may not be responsible for the excess, but the association deserves close attention in future studies.

A time series analysis of data collected from an isolated population of Culex pipiens quinquefasciaitus is presented. Sinusoidal curves for a period of 1 year were fitted to egg raft numbers, numbers of eggs per raft, numbers of hatched eggs per raft, immature stages and adults. Circannual rhythms for both daily high and low temperatures were detected. Seasonal changes in the time distribution of oviposition are presented. During warm weather, oviposition peaks occur just after sunset and again near dawn. This pattern changes in cold weather with the elimination of morning oviposition. The relationship of feeding and subsequent oviposition is discussed. Evidence is presented that indicates that temperature dependence is present throughout all stages of this moquito's life history.

In the past decade, shifts in tax policy have produced significant windfall gains and losses. This study has introduced a cashflow model for computing windfalls accruing to equity shareholders. Pre...

We used a predominantly diploid Chinese hamster cell line to test a number of naturally occurring and synthetic estrogens for their ability to arrest cells at metaphase, their potential for allowing anaphase recovery, and their capability of inducing aneuploid progeny. The chemicals employed included diethyl-stilbestrol, dienestrol, hexestrol, β-estradiol, ethynylestradiol and estriol. We also tested progesterone, estrone and testosterone in this regard. Only estrogens and their synthetic analogs caused mitotic arrest and aneuploidy, while progesterone, estrone and testosterone did not cause mitotic disturbances. Among the estrogens, DES was the most effective arrestant on a comparative molar basis, whereas dienestrol was most potent over a wide range of concentrations. Estriol was the least potent as an arrestant but was an effective inducer of aneuploidy. The addition of a metabolic activator (S9) did not alter the ability of DES to arrest mitosis. Following the removal of the drugs, cells were able to quickly reorganize a spindle apparatus and enter anaphase. Diethylstilbestrol, dienestrol, hexestrol, β-estradiol, ethynylestradiol and estriol caused significant increase in aneuploidy within a narrow range of high concentrations in recovering cell populations. Aneuploidy was induced in a non-random manner. Immunofluorescence studies with anti-tubulin antibody indicate that estrogens may have a mechanism of mitotic arrest similar to that of colchicine and colcemid, viz inhibiting the polymerization of tubulin to form microtubules. These data suggest that the interaction between estrogens and microtubules may mediate the induction of aneuploidy in somatic cells. Aneuploidy induction by DES and similar compounds may be related to their carcinogenic potential.