Search PubMed⌕ Search

Biomedical subjects

C A Brooks

Publications and source records attributed to C A Brooks.

31 records · Page 2Linked to original sources

A seroepidemiologic survey of the prevalence of herpes simplex virus type 2 infection in the United States.

The prevalence of infection with the genital herpes simplex virus type 2 (HSV-2) has been difficult to ascertain, primarily because of the large percentage of subclinical cases and the limitations in specificity of serologic assays for antibody to HSV-2. To obtain an improved estimate of the distribution of HSV-2 infection in the United States, we used an HSV type-specific antibody assay to test serum samples from 4201 participants in the second National Health and Nutrition Examination Survey. The results in our sample indicate that in the period from 1976 to 1980, 16.4 percent of the U.S. population 15 to 74 years of age (approximately 25 million persons) was infected with HSV-2 (95 percent confidence interval, 14.2 to 18.6 percent). Age and race were the demographic factors associated most strongly with the presence of HSV-2 antibody. The prevalence of the antibody increased from less than 1 percent in the group under 15 years old to 20.2 percent in the group 30 to 44 years old; it increased only slightly thereafter. In the oldest group, 60 to 74 years of age, the prevalence was 19.7 percent in whites and 64.7 percent in blacks. Among blacks of all age groups, but not whites, higher rates were observed in women than in men. The associations were weaker with respect to marital status, income, education, urban residence, and region of the country. After control for age, sex, and race, only the association with marital status remained significant; the rate was increased in persons previously married--i.e., divorced, separated, or widowed. We conclude that the prevalence of HSV-2 infection in the United States is higher than has previously been recognized and that many infections with this sexually transmitted virus may be subclinical.

Adolescent↗

Effect of salicylhydroxamic acid on endosperm strength and embryo growth of Lactuca sativa L. cv Waldmann's Green seeds.

Salicylhydroxamic acid (SHAM) stimulated germination of photosensitive lettuce (Lactuca sativa L. cv Waldmann's Green) seeds in darkness. To determine whether SHAM acts on the embryo or the endosperm, we investigated separately effects of SHAM on growth potential of isolated embryos as well as on endosperm strength. Embryo growth potential was quantified by incubating decoated embryos in various concentrations of osmoticum and measuring subsequent radicle elongation. Growth potential of embryos isolated from seeds pretreated with 4 millimolar SHAM was equal to that of untreated controls. Rupture strength of endosperm tissue excised from seeds pretreated with SHAM was 33% less than that of controls in the micropylar region. To determine if the embryo must be in contact with the endosperm of SHAM to weaken the endosperm, some endosperms were incubated with SHAM only after dissection from seeds. Rupture strength of SHAM-treated, isolated endosperms in the micropylar region was 25% less than that of untreated controls. There was no difference in rupture strength in the cotyledonary region of endosperm isolated from seeds treated with SHAM in buffer or buffer alone. SHAM therefore stimulates germination not by enhancing embryo growth potential, but by weakening the micropylar region of the endosperm enclosing the embryo.

Darkness↗

Predicting acute pelvic inflammatory disease: a multivariate analysis.

A multivariate logistic regression analysis of patient symptoms and signs and laboratory findings associated with the diagnosis of acute pelvic inflammatory disease was performed with use of data from 628 women who were clinically diagnosed as having the disease for the first time at the University of Lund, Sweden. In 414 women (65.9%) acute pelvic inflammatory disease was laparoscopically confirmed. We developed a mathematical model that correctly predicted 87.0% of the cases of acute pelvic inflammatory disease and had an overall correct classification rate of 75.6%. Variables that were good predictors of acute pelvic inflammatory disease were purulent vaginal discharge, erythrocyte sedimentation rate greater than or equal to 15 mm/hr, positive gonorrhea result, adnexal swelling on bimanual examination, and rectal temperature greater than or equal to 38 degrees C. Furthermore, we developed "mixed model I" and "mixed model II," which combine simple clinical parameters and laparoscopy in varying degrees. In mixed model I the sensitivity, specificity, and overall classification values were 93%, 67.2%, and 84.5%; in mixed model II these values were 100%, 67.2%, and 89.2%. Use of relatively simple and reproducible clinical parameters can identify those women who would most benefit from laparoscopy to diagnose acute pelvic inflammatory disease.

Acute Disease↗

Salicylhydroxamic acid potentiates germination of 'Waldmann's Green' lettuce seed.

A combination of salicylhydroxamic acid (SHAM) + cyanide (CN) is known to stimulate dark germination of Lactuca sativa L. seeds. Further studies were done to characterize SHAM and CN action in stimulating dark germination of lettuce seed. Germination was stimulated slightly by either SHAM or CN, whereas when SHAM and CN were combined germination was greatly enhanced. Treatment of seeds with SHAM + CN only during the first 8 hours of hydration stimulated germination as much as did treatment for 72 hours. During the first 8 hours of incubation in SHAM + CN, potentiation (i.e. domancy-breaking) of germination occurs. SHAM alone stimulated potentiation nearly to the level of SHAM + CN but inhibited subsequent radicle elongation, thereby decreasing germination when present for 72 hours. Oxygen must be present for SHAM or SHAM + CN to potentiate dark germination. The ability of SHAM and SHAM + CN to potentiate germination is influenced by O2 concentration and the timing of chemical treatment.

Cell Respiration↗

The distribution of six enzymes of oxidative metabolism along the rat nephron.

Using quantitative methods, citrate synthase (CS), fumarase, beta-hydroxyacyl-coenzyme A (CoA) dehydrogenase (beta OAC), 3-keto-acid CoA transferase (KCT), malic dehydrogenase (MDH), and malic enzyme were measured in seven defined parts of the nephron and in thin limb and papilla areas dissected from freeze-dried microtome sections of rat kidney. The results not only show a wide range of activity along the nephron for each of the enzymes, but that the proportions between the enzymes vary markedly among the different parts of the nephron. This suggests the existence of major regional differences in the capacity to oxidize specific metabolites. The ratio between two citrate cycle enzymes, fumarase and CS, was 4- or 5-fold higher in proximal segments than in the glomerulus or thin limb areas. The ratio between beta OAC (an enzyme of fatty acid oxidation) and CS was 3- to 5-fold higher in the middle proximal segments than in glomeruli or thin limb and papilla areas. The key enzyme for ketone body metabolism, KCT, was essentially confined to the thick tubule segments. Malic enzyme, in contrast to the other five enzymes, was highest in the proximal straight segments. New methods, sufficiently sensitive for this histochemical study, are described for malic enzyme and 3-keto-acid CoA transferase.

3-Hydroxyacyl CoA Dehydrogenases↗

A framework for: what can and should society do?

Researchers strive to better understand the critical periods of brain development. Findings generate clearer descriptions of what the critical periods are and suggest that stress, aggression, and violent behavior affect the development process. But the question remains as to what can and should society do to nurture children through these periods and to support their continued growth and development. Operation Peace in Philadelphia, an urban community-based, violence prevention/reduction initiative using the principals of public health, represents a framework for generating fresh attitudes and innovative support systems that will nurture children through the critical periods of brain development and beyond. This framework enhances understanding of the complexities of societal issues such as violent behavior and uncovers and offers communal solutions. It is a link between research and its practical application--what society can do. Society's challenge echoes Operation Peace's challenge to use the combined strengths of scientific knowledge, multidisciplinary skills, sustained commitment, cultural vitality, community support, and political will to enable youth to achieve their potential, via full and active lives.

Brain↗

National surveillance for neonatal herpes simplex virus infections.

To explore the magnitude and descriptive epidemiology of neonatal herpes simplex virus (HSV) infection, the Centers for Disease Control (CDC) conducted an 18-month hospital-based surveillance study in which 184 cases were reported. Only 22% of mothers had a history of genital HSV infection and only 9% had genital lesions at the time of delivery. Cesarean delivery initiated prior to membrane rupture failed to prevent infection in 15 cases. These data confirm previous observations that most mothers of infected neonates have no history of genital HSV and are asymptomatic at delivery. Furthermore this study suggests that intrauterine infection may be an important route of transmission and underscores the limitations of current prevention strategy.

Adolescent↗