Lung aryl hydrocarbon hydroxylase: Inhibition following cadmium chloride inhalation

Polycyclic hydrocarbon metabolism in male Spraque-Dawley rats following inhalation of aerosolized cadmium chloride (CdCl₂) was examined. Constitutive activity of microsomal aryl hydrocarbon hydroxylase (AHH) (benzo(a)pyrene substrate) was monitored in lung and liver homogenates up to 10 days after exposure. Lung AHH activity was reduced by 85% during the first 2 days following cadmium inhalation, and did not return to normal levels until 7 days after exposure. Enzyme activity in the livers of cadmium-treated animals was similarly depressed (by 65%) within 24 hr. Cadmium inhalation also inhibited (by 50%) 3-methylcholanthrene (MC) induction of lung AHH when compared with MC-treated controls. No significant effect on AHH inducibility by MC was noted in liver homogenates from cadmium-exposed animals. Nonspecific microsomal damage appeared not to occur since glucose-6-phosphatase activity in lung was unaffected by cadmium treatment. Although the mechanism of cadmium's action remains unclear, it appears not to involve a direct interaction of the metal with enzyme. The alteration of AHH activity by cadmium may result from injury to a specific cell type within the lung, which may be a major site of pulmonary AHH activity, or may result from modulation of synthesis and/or degradation of heme proteins in the lung. These results suggest that cadmium, under these conditions, markedly reduces the constitutive and inducible activity of AHH in the lung.     

A survey of blood pressure in the state of Maryland

To provide baseline data for a state program to coordinate hypertension resources, a blood pressure (BP) survey was undertaken in Maryland in 1978. A statewide probability sample of households was chosen; each adult member was eligible for interview and measurement of BP. A total of 6,425 adults were interviewed for an overall response rate of 79.5%. Using a definition of diastolic blood pressure (DBP) of 95 mm Hg or higher or use of antihypertensive medication, 15.1% of state residents were estimated to be hypertensive. Of these, 85.8% were estimated to be aware of their condition, 77.6% of them were treated, and 67.6% had their BP controlled to a normal level by medication. Data are also presented using DBP 90 mm Hg or higher. A comparison of data from the Hypertension Detection and Follow-up Program (HDFP) home screen in 1973–1974 and comparable information from this survey showed lower rates of awareness, treatment, and BP control in hypertensives at HDFP home screen. Results of this survey will be compared with those of a second statewide survey conducted four years later to assess changes in rates of hypertension awareness, treatment, and control.     

Variability and reliability of diastolic blood pressure during adolescence: The Philadelphia blood pressure project

This paper reports results of diastolic blood pressure studies done as part of the Philadelphia Blood Pressure Project (PBPP), a 3-year longitudinal study of black adolescents, initially ages 11–15, who were enrolled originally in the Philadelphia Collaborative Perinatal Project (CPP). Three samples were studied by the PBPP: a representative sample of over 500 black adolescents stratified by age and sex, a smaller sample of adolescents who had blood pressures elevated beyond one standard deviation of the CPP population mean at age 7, and a sample of adolescents born of toxemic pregnancies. We found, for the representative sample, consistent differences in the means of diastolic blood pressure phases IV and V and between diastolic blood pressures taken in supine and seated positions. Supine diastolic blood pressures were more variable at every age and were lower than the comparable seated diastolic blood pressures. In addition, we estimated on a random subsample from all three samples diastolic blood pressure reliability for supine readings taken sequentially by the same (N = 96) and different (N = 55) examiners. We also estimated measurement reliability simultaneously (N = 91 supine, N = 96 seated) using a double-listening stethoscope. We found that although diastolic phase IV blood pressure was more reproducible or less variable over short periods of time (5–15 min) when reliability measures were taken sequentially, two examiners simultaneously could not measure phase IV with significantly greater accuracy than phase V. We concluded that the fourth and fifth Korotkoff sounds should not be used interchangeably during adolescence and that postural position is an important contributor to diastolic blood pressure variance during adolescence. Also, since it has not yet been established which is more statistically predictive of adult blood pressure levels, whenever possible, both phase IV and V should be recorded for adolescents.     

Alcohol consumption and blood pressure: analysis of data from the Canada Health Survey

Recent epidemiologic studies report a significant association between alcohol consumption and elevations in both systolic (SBP) and diastolic (DBP) blood pressures. To test this hypothesis, we conducted a multivariate analysis of physical examination and other data on 721 men and 697 women aged 20 or more collected during the Canada Health Survey in 1978-1979. SBP and DBP were considered as separate dependent variables in multiple regression models with the following independent variables: age, alcohol consumption (measured as a 7-day recall history and as an average frequency of consumption), serum cholesterol, plasma glucose, physical activity, Quetelet index, parental history of hypertension, cigarette consumption, income, education, and exogenous hormonal use in women. In both weighted and unweighted multiple regression analyses, we could not demonstrate for either sex, a significant association between alcohol consumption (as recorded and following quadratic and logarithmic transformations) and either SBP or DBP. For both sexes, only age and Quetelet index were highly significantly (P less than 0.0001) and consistently associated with both SBP and DBP. No other independent variables were consistently associated, for either sex, with SBP and DBP. Further, the dose-response patterns noted by other investigators suggesting either a positive and linear relationship or a curvilinear relationship were not found in either our univariate or multivariate analyses. Rather, the alcohol-blood pressure curves showed no consistent patterns of any kind in either sex. These findings do not support recent claims that alcohol consumption is a determinant of elevations in either SBP or DBP.     

Intrauterine devices and menstrual blood loss. A comparative study of eight devices during the first six months of use

An experiment was conducted to determine changes in menstrual blood loss caused by IUDs. 78 volunteer women of similar age and parity were randomly selected from among those requesting IUDs from the outpatient department of the National Medical Center of the Mexican Institute of Social Security. Menstrual blood loss and hemoglobin were measured for 1-2 control cycles and for 6 postinsertion cycles. Of the 8 different types of IUDs used, the Lippes Loop and the copper-releasing devices caused a statistically significant increase in blood loss and a related decrease in hemoglobin. The steroid-releasing devices caused no significant increase in blood loss and no significant changes in hemoglobin concentration. The rigid copper devices caused the greatest increase in blood loss. The noted changes were clearly established by the 3rd postinsertion cycle.     

The effects of chronic administration of LH-RH agonists and antagonists on the menstrual cycle and endometrium of the rhesus monkey

Regularly cycling rhesus monkeys (Macaca mulatta) were used to study the effects of prolonged administration of LH-RH analogs on the menstrual cycle and the endometrium. According to the treatment, animals were divided into: Group 1, vehicle; Group 2, LH-RH agonist (D-Trp6 LH-RH, 20 micrograms/day); and Group 3, LH-RH antagonist [( N-Ac-D-Trp1,3, D-p-Cl-Phe2,D-Arg6,D- Ala10 ]-LH-RH,200 micrograms/day) for 90 days. Follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2) and progesterone (P) were measured every second day until thirty days past the discontinuation of drug administration. Endometrial biopsies were obtained on days 10, 40, 90 and 120 and processed for histologic exam and determination of estrogen (E) and progesterone receptors. Animals of Group 1 presented regular cycles, while those in Groups 2 and 3 remained anovulatory throughout the treatment. Animals of Group 2 presented different degrees of endometrial hyperplasia during treatment and animals of Group 3 showed either resting or atrophic endometrium. Administration of LH-RH agonist produced a marked increase in E and P endometrial receptors and the antagonist produced a decrease in P receptors. In both instances, reversal of the effects on the menstrual cycle and in the endometrium was observed 30 days after discontinuation of drug administration.     

Community participation in the control of trachoma in Gazankulu

Groups of villagers, the care groups, are involved in prevention and treatment of trachoma within their own communities. The effect of the scheme on standards of hygiene and prevalence of trachoma has been evaluated by randomised cluster sampling methods. The number of households who were digging refuse pits, acquired individual face cloths and were aware of the role of good hygiene in the prevention of trachoma exceeded significantly those in (control) villages without a care group, in contrast the acquisition of pit latrines showed an insignificant increase. The prevalence and intensity of active trachoma was found to be significantly reduced as a result of the intervention of the care groups. This scheme has been totally integrated into the primary health care system of the area.     

Yields of selected toxic agents in the smoke of Canadian cigarettes, 1969 and 1978. A decade of change?

Canadian sales-weighted averages of cigarette carbon monoxide (CO) and tar have been evaluated for the decade ending 1979. Virtually no change occurred up to 1976; between 1976 and 1979 the sales-weighted average CO dropped from 21 to 16 mg with a much smaller decrease in the corresponding values for tar (16.1 to 14.4 mg). Thus changes in CO deliveries did not take place at the same rate as changes in tar deliveries. If standardized smoking machine yields are related to the risk of smoking-related morbidity and mortality, the low correlation and the 8-year lag time in the curves describing the decrease in two of the major toxic constituents of cigarette smoke may be of importance in helping to explain a lower impact of less hazardous cigarettes on coronary heart disease (CHD) rates. Assuming that exposure to CO is a risk factor for CHD, the relatively recent reduction in sales-weighted CO yields might have the effect of decreasing CHD rates among smokers in the future. In addition to CO yields, HCN, acrolein, and total aldehyde yields of 25 brands of cigarettes manufactured in 1969 were compared with yields of the same cigarettes manufactured in 1978 in order to assess changes which may have occurred in other gas phase constituents. Significant decreases were noted in the yields of all constituents other than CO; the average decrease per brand was HCN, 69 μg; total aldehydes, 114 μg, and acrolein, 5.2 μg.     

Serum cholesterol, diet, and the decline in coronary heart disease mortality

There has been a recent and dramatic decline in coronary heart disease death rates in the United States. The possible contribution of secular trends in serum cholesterol to this decline was examined by comparison of data from five epidemiologic studies: the Framingham Study, the Tecumseh Study, the Health Examination Survey, the Health and Nutrition Examination Survey, and the Lipid Research Clinics Program Prevalence Study. It appears that in the 1960s there was a modest decline in serum cholesterol levels (approximately 5 mg/dl in middle-aged adults). Although it is impossible to exclude methodologic variation as the main explanation for the observed trends, the contribution of dietary changes to this decline was also examined, by comparison of data from the Diet-Heart Study and the Lipid Research Clinics study. The decline in serum cholesterol was found to be consistent with the observed changes in dietary fat intake in the 1960s. When the potential impact of the decline in cholesterol levels on coronary heart disease death rates was assessed by use of a Framingham multivariate logistic risk function, it was found that a decline in cholesterol of 5 mg/dl would predict a 4.3% decline in 6-year coronary heart disease death rates in middle-aged men.     

Effect of urethane, dimethylnitrosamine, paraquat and butylated hydroxytoluene on the activities of glycolytic key enzymes in mouse lung

Effects of carcinogens and noncarcinogenic pulmonary toxicants on the activities of glycolytic key enzymes in the mouse lung were investigated. The carcinogens urethane (URTH) and dimethylnitrosamine (DMN) permanently enhanced, and the noncarcinogenic pulmonary toxicants paraquat (PAR) and butylated hydroxytoluene (BHT) temporarily, enhanced the activities of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK) in the lungs of mice.     

Female reproductive organs and breast cancer mortality in New Jersey counties and the relationship with certain environmental variables

Age-adjusted female reproductive organs and breast cancer mortality rates (all sites combined) were higher in 19 of 21 New Jersey counties than the U.S. national rates. Compared with national trends, New Jersey cervical cancer and corpus uteri rates have declined less than the national rate among all races. Ovarian and breast cancer rates have not changed over the years, a pattern similar to that of the nation. New Jersey cancer mortality rates during the period 1968-1977 that highly significantly (P less than 0.0005) exceeded national rates were cancers of the cervix in 2 counties among whites and in one county among nonwhites; of the corpus uteri and uterus not specified in 3 counties among whites; of the ovaries in 3 counties among whites; and of the breast in 10 counties among whites. The overall New Jersey cancer mortality significantly (P less than 0.0005) exceeded national rates for ovarian cancer among whites and nonwhites and for breast cancer among whites. Statistically significant and positive correlations were found between breast cancer mortality and chemical toxic waste disposal sites, annual per capita income, urbanization index, and population density among whites in 21 New Jersey counties. Ovarian cancer mortality was also significantly and positively correlated with annual per capita income, and negatively with birth defects. Cervical cancer mortality showed a significant negative correlation with annual per capita income and a significant positive correlation with birth defects and low birth weight among nonwhites in 21 New Jersey counties.     

The role of patient education in the management of childhood asthma

Because patient behavior plays a major role in the prevention or precipitation of acute asthma attacks, patient education is an important adjunct to its medical management. A number of self-management education programs for patients with asthma recently have been developed and made available for widespread use. Many are aimed at children over the age of 6 years and their parents. They are designed for use with several types of patients in a variety of settings. Evidence of program effectiveness is of uneven quality, but what is available suggests that a number of the programs can be of significant value in reducing asthma morbidity. Self-management education programs for parents of preschool-age children and for adults with asthma are much less numerous and well developed than those for school-age children. Particular attention is given to the process by which the AIR POWER and AIR WISE programs for children were developed, since this systematic development process is generalizable to patient education programs for other age groups and health problems.     

Distributions and determinants of total and high-density lipoprotein cholesterol in Dutch children and young adults

Serum total cholesterol and its putative determinants were measured in 5,089 subjects, ages 5-30 years, comprising 76% of the total population of two districts of the Dutch town of Zoetermeer. From this group, 596 subjects, ages 5-19 years, were randomly selected, and distributions and determinants of high-density lipoprotein (HDL) cholesterol were studied in 458 of them. The variables studied included body weight; Quetelet index; menarche; parental cholesterol; physical activity; consumption of coffee, alcohol, and tobacco; and use of oral contraceptives. Mean total cholesterol levels showed a decrease in both boys and girls between the ages of 10 and 16 years. Mean HDL cholesterol levels remained the same until the age of 17, after which they showed an increase for females and a decrease for males. Total cholesterol was associated with age, body weight (in those older than 15 years), and parental cholesterol concentrations. For HDL cholesterol, the most important determinants were gender, age, and body weight (the latter only for males 15 years and older). These findings suggest that during growth and maturation the determinants of serum cholesterol differ from those later on in life.     

Knowledge of and attitudes toward coronary heart disease and nutrition in Oregon families

In an effort to examine knowledge about heart disease and nutrition and attitudes toward dietary change, 754 women and 125 men were interviewed. The majority of respondents recognized the association between coronary heart disease and various risk factors, including dietary cholesterol. Although they acknowledged the value of dietary change in reducing risk, the majority denied that the food they now eat increases their risk for heart disease, which suggests a lack of perception about possible benefits to be derived from dietary change. The importance of addressing perceived barriers to change is discussed.     

Effect of the chelating agent sodium tripolyphosphate on cadmium toxicity in mice

The mechanism by which Sodium tripolyphosphate (STPP) increases cadmium toxicity after sc administration was investigated in mice after a dose of Cd (30 μmole/kg), alone or with STPP (90 μmole/kg). The effects of STPP on acute Cd toxicity, development of Cd-induced liver necrosis, rate of Cd transport, distribution of Cd among organs, and Cd binding to metallothionein (MT) was followed. Histological liver changes were not observed during the first 12 hr after injection of Cd, but already 6–8 hr after injection of Cd + STPP early centrilobular necroses and blood stasis appeared. At 12 hr more advanced necroses were present. STPP administered alone was nontoxic and did not change the liver morphology, when compared to animals killed immediately after injection. During the first 12 hr after administration of Cd with STPP there was a much faster transport of Cd giving rise to higher liver and kidney concentrations of Cd and partial inhibition of Cd-MT binding, compared with animals receiving the same dose of Cd without STPP.     

Prevention and health promotion in primary care: baseline results on physicians from the INSURE Project on Lifecycle Preventive Health Services

The INSURE Project on Lifecycle Preventive Health Services is a 3-year feasibility study to develop and test a clinical model of preventive health services, including patient education, in primary medical care as an insurance benefit. Seventy-four primary care physicians in group practices were surveyed regarding their baseline attitudes toward, and practice of, preventive services. Physicians report that they tend to be conscientious in educating their patients about their health risks, although they spend little time in patient education. Physicians are not sanguine about their success in getting their patients to follow their recommendations and tend to harbor doubts about their own efficacy in these areas. Specialty differences exist in these parameters. Physicians evidence contradictory attitudes about prevention. They believe doctors should spend more time providing preventive services but also believe that the lack of insurance reimbursement is an obstacle to providing these services. The concept of structural or sociological ambivalence is advanced to explain this pattern.     

Characterization of tobacco products: a comparative study of the tar, nicotine, and carbon monoxide yields of cigars, manufactured cigarettes, and cigarettes made from fine-cut tobacco

Yields of tar, nicotine, and carbon monoxide were compared in selected Canadian brands of manufactured and hand-rolled cigarettes, and small and large cigars. To control for varying volumes of smoke delivery per cigarette or cigar, standardized comparisons in milligrams of toxic substance per liter of smoke were made. The mean deliveries per liter of smoke and tar, nicotine, and carbon monoxide were highest for small cigars, followed by hand-rolled and manufactured cigarettes; large cigars had the lowest deliveries. Five out of six brands of cigarettes handmade from fine-cut tobacco delivered significantly more tar, nicotine, and carbon monoxide per cigarette or per liter than did the identically named manufactured brand.     

The description and initial evaluation of an intensive live-in program in risk reduction

Drawing upon the epidemiological, clinical, and behavioral studies suggesting the importance and feasibility of multidisciplinary efforts to reduce levels of risk variables for cardiovascular and other chronic diseases, a short-term live-in intervention program was developed. The program includes efforts to reduce smoking, weight, blood lipids, blood pressure, and stress through improving habits of exercise, nutrition, weight management, and stress control delivered to individuals with varying levels of health risk based on measurable biochemical and physiological variables and medical history. Major changes occurred during the 24-day program in 459 individuals enrolled in the program: 68% of smokers ceased, average cholesterol fell from 240 to 200 mg%, ideal body weight fell from 134 to 129% (82 to 79 kg), systolic blood pressure (BP) fell from 131 to 119 mm Hg, diastolic BP fell from 81 to 73 mm Hg, and reported feelings of general well-being increased. Greater changes were observed in the high-risk groups. Follow-up results at 1 year (48% of patients reporting) for those defined as high risk were a net decrease of 22 mg% in cholesterol, 7 mm Hg in systolic BP, 6 mm Hg in diastolic BP, and 6.8% of ideal body weight; 45% of those smoking at admission were still not smoking at 1 year (32% reporting). For those at lower risk there was a general return of risk levels toward baseline values.     

A comparison of the yields of tar, nicotine, and carbon monoxide of 36 brands of Canadian cigarettes tested under three conditions

A number of countries, including Canada, sponsor routine monitoring of cigarette tar, nicotine, and carbon monoxide yields which are evaluated by cigarette-smoking machines according to a standard protocol. These standardized yields continue to decline as tobacco companies modify their brands to meet consumers' demand for "light" products. This trend toward cigarettes with low average deliveries of toxic substances may reduce health risks for some people. However, switching to low-yield cigarettes may not result in reduced risks for smokers who smoke these cigarettes intensively. Thirty-six brands of Canadian cigarettes, including 28 with ventilated filters, were tested under standard conditions and 2 others in order to determine how yields of tar, nicotine, and carbon monoxide change when cigarettes are manipulated by smokers in order to increase their smoke intake. While the rank order yields of tar, nicotine, and carbon monoxide was preserved, the average yields of all three substances more than doubled when cigarettes were intensively smoked in comparison with standard smoking.