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Biomedical subjects

L G Dales

Publications and source records attributed to L G Dales.

At least 19 recordsLinked to original sources
PubMed1993

Measles epidemic from failure to immunize.

During 1988 through 1990, California experienced its worst measles epidemic in more than a decade, with 16,400 reported cases, 3,390 hospital admissions, and 75 deaths. More than half of the patients were younger than 5 years; the highest incidence was among infants younger than 12 months. The epidemic centered in low-income Hispanic communities in southern and central California. The major cause of the epidemic was low immunization levels among preschool-aged children and young adults. Rates of complications, admission to hospital, and death were surprisingly high. Outbreak control efforts met with indeterminate success. Problems with these efforts included insufficient funding early in the epidemic and disappointing public response to community-based immunization campaigns. The cost of medical care and outbreak control for the epidemic is conservatively estimated at $30.9 million. Unless the level of immunization in preschool-aged children is increased, this type of epidemic will probably recur.

Adolescent↗
PubMed1993

Response of human immunodeficiency virus-infected adults to measles-rubella vaccination.

Measles-mumps-rubella vaccine (MMR) is recommended for human immunodeficiency virus-infected (HIV+) adults. Data concerning MMR vaccination of HIV+ patients are limited to children. We evaluated 39 HIV+ (97% with > 200 CD4+ lymphocytes) and 17 non-HIV+ control adults receiving measles-rubella vaccine (MR). Clinical adverse events did not differ between groups. Prevaccination, three HIV+ and two control vaccinees were measles seronegative; no HIV+ and one control vaccinee seroconverted. No initially measles-seropositive vaccinee had a significant antibody elevation. Four HIV+ and three control vaccinees were rubella seronegative prevaccination; three HIV+ and two control vaccinees seroconverted. Among those initially rubella seropositive, two HIV+ and one control vaccinee had significant antibody elevations. There were no significant percentage CD4+ or CD8+ lymphocyte changes between groups. Three HIV+ vaccinees were p24 antigen positive pre- and postvaccination. Although MR vaccination appears safe in HIV+ adults, questions remain about the response of measles and rubella antibody-negative HIV+ adults and those with < 200 CD4+ lymphocytes.

Adult↗
PubMed1991

Clinical efficacy of measles vaccine during the 1990 measles epidemic.

Because of increased measles incidence in the United States during 1989 and 1990 and the recent finding of genomic differences between vaccine virus and contemporary wild measles viruses, we conducted a study to determine whether the current measles vaccine had become less effective. Household secondary attack rates for 203 California children ages 1 to 5 years were 4.2 and 77.8% for vaccinated and unvaccinated children, respectively, and the vaccine efficacy was 95% (95% confidence interval: 89%, 97%). The protective efficacy for postexposure vaccination and use of IG were both low, 4% (95% confidence interval: less than 0, 36%) and 8% (95% confidence interval: less than 0, 59%), respectively. The measles vaccine efficacy found in this study is similar to those obtained in previous years and indicates that the measles epidemic of 1989 to 1990 occurred despite high vaccine effectiveness.

California↗
PubMed1986

Transmission of measles in medical settings. 1980 through 1984.

For the five-year period 1980 through 1984, a total of 241 persons with measles in 30 states were identified as probably having acquired their infection in a medical facility. The proportion of all measles cases acquired in medical settings increased from 0.7% for 1980 through 1982 to 2.9% for 1983 and 1984. Seventy-six percent of cases were found in patients or visitors, and 24% in personnel at the medical facility where transmission occurred. The highest proportion of cases occurred in children less than 5 years of age (54.3%), followed by persons 25 to 29 years of age (14.7%). Of spread (50.0%) and patient-to-staff spread (36.7%) were most common. Medical personnel rarely transmitted disease to others. More attention needs to be given to methods of preventing spread of measles in medical facilities, such as isolation precautions, postexposure prohylaxis of potential contacts (vaccination or immune globulin), and ensuring that medical personnel are immune to measles.

Adult↗
PubMed1982

Frequency of urolithiasis in a prepaid medical care program.

The rate of occurrence of stones of the urinary tract was assessed in a large population served by the Northern California Kaiser Foundation Health Plan. The study involved three separate groups. First, data were obtained by questionnaire from approximately 175,000 adults who took a multiphasic health checkup in the period 1964-1972; of these generally well adult members, 26.2/1000 persons (32.0/1000 men and 21.0/1000 women) reported having ever been told by a physician that they had a urinary tract stone. Second, data were obtained from 139,000 persons served by the San Francisco outpatient facility in 1970-1972; 1.22/1000 per year (1.81/1000 men and 0.59/1000 women) had an initial diagnosis of a "new or recurrent" stone of the upper urinary tract. The third set of data was procured from the entire Northern California region in 1971-1975; 0.36/1000 (0.52/1000 men and 0.19/1000 women) were discharged from a hospital each year with a diagnosis of upper urinary tract stone. All rates were age-adjusted to the 1960 US Census population. Of these three rates, the rate derived from the outpatient visit record most closely estimates incidence, since nearly all persons who are hospitalized are first seen as outpatients. Rates of kidney stone diagnosis were three times more common in men and, although rare before 20 years of age, the frequency increased rapidly and peaked in the age group 40 to 59 years. Rates were approximately twice as high in whites as in blacks and Orientals; the frequency of stones was inversely related to socioeconomic status as measured by level of education. Over 90% of stones occurred in the upper urinary tract, and the majority contained calcium oxalate. Population-based rates of occurrence of kidney stones are not generally available in the United States. Comparisons with the few available studies indicate that rates in the Kaiser Foundation Health Plan population may be high.

Adolescent↗
PubMed1982

Public health implications of rubella antibody levels in California.

Rubella hemaggluttination inhibition (HI) antibody determinations were performed in 1977 on a sample of California school children and in 1977-1979 on young women who were about to be married or who were pregnant. Among the pupils, 66 per cent reported prior rubella immunization; immunization history was more common in younger pupils. Seventy-seven per cent had detectable antibody, with little trend of greater seropositivity at older ages. Over 86 per cent of those with a written record of immunization had detectable antibody. There was no consistent indication of loss of seropositivity with increasing time since immunization. Children immunized at 12-14 months of age tended to have a lower seropositivity rate than those immunized at older ages. Among young women, the prevalence of detectable antibody was 80-83 per cent. Comparison with data obtained in 1968-1969 indicates that rubella immunization has had a marked impact on antibody levels in children but less impact on levels in teenagers and adults. The pool of rubella-susceptibles entering secondary schools will probably not decrease soon, so that rubella outbreaks may continue in high school and college-age populations. Ultimately, school entry immunization requirements should drastically curtail disease activity. In the interim, programs to immunize teenagers and young adult females must be strengthened. (Am J Public Health 1982; 72:167-172.)

Adolescent↗
PubMed1981

An outbreak of congenital rubella.

A large outbreak of rubella occurred in the San Francisco Bay Area in early 1979. Later that year and in early 1980, 13 cases of confirmed or probable congenital rubella syndrome were reported. Results of a subsequent investigation strongly suggest that these two events were related in a causal manner and do not represent an indirect association based on changes in diagnostic or reporting thoroughness. To prevent such episodes in the future, renewed emphasis must be placed on routine immunization of young children of both sexes, rigorous enforcement of school-entry immunization laws and selective immunization of women of childbearing age.

Adolescent↗
PubMed1979

Mortality in middle-aged smokers and nonsmokers.

We assessed the relation of cigarette smoking to mortality in an 11-year follow-up study of 4004 men and women, 35 to 54 years of age, who responded to urging to have multiphasic health checkups. Accounting for 48 other characteristics, both individually and in combination, failed to eliminate the association of smoking with mortality from all causes or with mortality from coronary heart disease. The smoker-to-nonsmoker mortality ratios, crude and adjusted respectively, were 2.6 and 2.1 for all causes and 4.7 and 3.6 for coronary heart disease. This analysis did not support the counterhypothesis that the association of cigarette smoking with mortality is secondary to some underlying characteristic.

Adult↗
PubMed1979

A case-control study of relationships of diet and other traits to colorectal cancer in American blacks.

Ninety-nine black colorectal cancer patients and 280 matched controls from hospitals and multiphasic health checkup clinics were interviewed about past dietary habits and other traits. The colon cancer cases tended to report less frequent use of foods with at least 0.5% fiber content than did their controls. This relationship, though small, showed a consistent dose-response gradient, appeared in both case-hospital control and case-multiphasic health checkup control comparisons, and could not be accounted for by the effects of other variables. Colon and rectosigmoid junction cancer patients tended to have eaten foods with at least 5% saturated fat somewhat more often than controls. When consumption of these two groups of foods was considered in combination, significantly more colon cancer patients than controls reported a high saturated fat foods-low fibrous foods eating pattern, as opposed to a low saturated fat foods-high fibrous foods diet. Statistically significant excesses of the following traits were also reported by the colorectal cancer patients: prolonged cigar smoking in men, nulliparity in women, and history of colorectal polyps.

Adenocarcinoma↗
PubMed1978

An improper use of statistical significance testing in studying covariables.

How badly a covariable confounds the association between a disease and a primary trait depends on the strength of two other associations: between covariable and disease, and between covariable and primary trait. To assess the confounding potential by testing one of these associations for statistical significance, using a 'traditional' critical level, is inadequate. Such a preliminary test places the burden of proof in the wrong direction, ignores a major aspect of confounding potential, and may be inappropriately influenced by other factors. If it must be used at all, the significance level should be 0.25 or 0.50, possibly even higher.

Statistics as Topic↗
PubMed1978

Cigarette smoking habits and urine characteristics: urinalysis abnormalities are more common is smokers, but the reasons are unclear.

Voided urines of 53,000 white and 9,3000 black cigarette smokers and nonsmokers were studied. Proteinuria was found to be commoner in smokers of both races and sexes. Heavy smokers showed proteinuria more frequently than light smokers. Of eight possible explanatory variables, one, alcohol consumption history, showed some interrelationship in that the smoking status-proteinuria association disappeared among heavy drinkers. Stopping smoking was not associated with a relative decline in proteinuria prevalence. Proteinuria associated with smoking did not appear to be indicative of more serious renal disease. There was a smoker-nonsmoker difference in urine glucose response to oral glucose challenge, apparently explained by higher average 1-hour serum glucose values for smokers, of unknown mechanism but partially explained by differences in alcohol usage. Hematuria, bacteriuria, and high urine acidity tended to be more prevalent in smokers, though these relationships were not consistently significant.

Adult↗
PubMed1975

Cigarette smoking and chest pain.

Analysis of questionnaire responses of 70208 persons undergoing multiphasic health checkups showed a greater proportion of cigarette smokers than nonsmokers (excesses averaging 1.6-fold in white men, 1.3-fold in white women) admitting to nine types of chest pain. This excess in smokers was greater in younger individuals, and applied about equally to anginalike and nonanginalike pain. The smoking/chest pain association was not explained by greater alcohol or coffee consumption, diminished pain tolerance, or less reliability among smokers; nor did it appear to be mediated chiefly by excess cough, shortness of breath, coronary disease, or musculoskeletal complaints in smokers. Although smokers averaged more complaints than nonsmokers, chest pain resembled clearly smoking-related symptoms, such as cough, when the number of each subject's complaints was considered. Although more smokers had chest pain no type of pain was unique to smokers, suggesting that the "tobacco angina" concept be discarded or reserved for rare patients with coronary heart disease in whom smoking clearly provokes angina pectoris.

Adolescent↗