T lymphocytes of young and aged rats. I. Distribution, density, and capping of T antigens

The distribution, density, and capping of the T cell antigens W3/13, W3/25, and Thy-1 were studied in lymphocytes of young (3 to 4 mo) and aged (greater than or equal to 27 mo) Brown Norway (BN) rats. The total number of W3/13, W3/25, and Thy-1 positive cells and the percentage of Thy-1 positive cells are reduced in the spleens and lymph nodes of aged rats. Analysis of spleen and lymph node cells in a fluorescence-activated cell sorter indicated that with ageing there is a loss of moderately and brightly stained W3/13 and W3/25 positive cells. The density of W3/13, W3/25, and Thy-1 is reduced on spleen and lymph node cells of old rats. The rate of capping of all 3 molecules is diminished on "old" cells. Colchicine treatment of young cells enhanced capping of all 3 molecules and allowed capping of W3/13 by a single ligand. However, capping on "old" lymphocytes was not affected by colchicine treatment. Cytochalasin D inhibited capping to the same extent on young and "old" cells. These results suggest that the membrane composition and cytoskeleton are altered in T lymphocytes of aged rats.

A comparison of utilization of community primary health care and school health services by urban Mexican-American and Anglo elementary school children

The health care utilization of urban Mexican-American and Anglo elementary school children was recorded at school and community primary-care sites over a 1-year period. No significant differences were found between the two groups with respect to visiting/nonvisiting behavior or frequency of visits. Two unobtrusive measures were used to ascertain the degree of acculturation of the Mexican-American children and their parents: return of Spanish-language questionnaire and enrollment of the child in bilingual classes. No significant differences were found in the proportion of visitors/nonvisitors in each group or the total number of visits for health services among these children. Mexican-American and Anglo children did not differ in the type of health problems presented, except that fewer Mexican-American than Anglo children had visits for emotional, behavioral or learning problems. Results indicate that when health services are available and accessible, and when the barriers of language and income are minimized, Mexican-American and Anglo children do not differ in their use of health services in the community.

Reaction patterns of herpes simplex virus type 1 and type 2 proteins with sera of patients with uterine cervical carcinoma and matched controls

Serum from 105 individuals with diagnosed uterine cervical cancer and 231 matched controls were examined for their ability to react with a large number of herpes simplex virus type 1 or type 2 (HSV-1, HSV-2) proteins. Radiolabeled HSV-1 or HSV-2 proteins were mixed with test serum and immune complexes were isolated with staphylococcal protein A. Viral proteins in the immune complexes were resolved by polyacrylamide gel electrophoresis and visualized by fluorography. When the frequency of precipitation for cancer and control serum was calculated for each HSV-1 and HSV-2 protein, the results demonstrated that four HSV-1 and 11 HSV-2 proteins were precipitated more frequently by cases than by controls (p less than or equal to 0.05). However, since these results could be influenced by the presence or absence of HSV-2 specific antibodies as well as social, economic, and sexual history, the data were grouped and analyzed according to these parameters. This enabled all significant differences between case and control sera in the precipitation of HSV-1 or HSV-2 proteins to be abolished except for two HSV-2 proteins with molecular weights of 38,000 and 118,000. These two proteins appear to be tumor associated and not merely covariables of past infection or risk factors alone.

A comparison of absentee rates of elementary schoolchildren with asthma and nonasthmatic schoolmates

Daily school attendance has been suggested as a health status measure for children. The present study compares school absence in children known to have asthma (N = 95) with a random sample of nonasthmatic elementary schoolchildren (N = 711). The differences in average percentage of days absent over one year were analyzed by comparing both groups' conditioning on ethnicity, sex, socioeconomic status, and grade. Children with asthma have a significantly higher absentee rate (absent 8.4% of days) than do nonasthmatic children (absent 5.9% of days) (P less than 9001). This significant difference holds true regardless of ethnicity of sex and for most socioeconomic groups. A comparison by grade level shows a similar trend for children with asthma and nonasthmatic children: absentee rates decrease as children get older; however, except for one grade level, children with asthma have a greater percentage of school days absent. Mean absentee rates for children with asthma were different when compared according to their mother's perception of severity of asthma--mild (6.9%), moderate (7.9%), and severe (13.9%).

Human parotid alpha-amylase secretion as a function of chronic hyperbaric exposure

Secretion of alpha-amylase by the human parotid gland increased significantly during eight days of hyperbaric exposure. This hyperactivity of the parotid gland presumably resulted from increased autonomic nervous system (ANS) activity attributable to (1)psychological stress in the form of anticipation; (2) dive-related factors, i.e., hyperoxia, PN2, physical stress; or (3) a combination of both. The etiology of the effect must await additional studies, but a consistent and significant elevation in alpha-amylas secretion was found. This previously undescribed effect of hyperbaric exposure indicates that parotid alpha-amylase sampling holds promise as a noninvasive means of monitoring physical and psychological stress, and as an indirect measure of ANS tone.

Changes in serum ferritin and other factors associated with iron metabolism during chronic hyperbaric exposure

Factors related to iron metabolism were determined in 20 United States Navy divers during 8 d of air saturation-excursion hyperbaric exposures. During these simulated dives progressive and correlated increases in serum ferritin and iron occurred. No significant changes were observed in bilirubin, hemoglobin, ceruloplasmin, transferrin, copper, or total iron binding capacity. The significance of the increased serum ferritin is discussed in relation to bone marrow damage and early detection of aseptic bone necrosis.

Detection of antibodies specific for herpes simplex virus in human sera by the enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay (ELISA) was used for the detection in human sera of antibody to herpes simplex virus antigens. Development and standardization of the assay suggested that antigenic purity, temperature of reactions, concentration of enzyme-conjugated antiglobulin, and concentrations of test sera are all critical parameters of a successful ELISA procedure. When ELISA titers of 30 human sera were compared to micro-complement fixation titers of the same sera, a significant degree of correlation was observed, but quantitatively ELISA was found to be up to 200 times more sensitive. The sensitivity of the assay and its adaptability to automation should provide an additional method for study or diagnosis of infection with herpes simplex virus.

The effect of diethyldithiocarbamate on passive avoidance learning by chicks (Gallus domesticus)

Diethyldithiocarbamate (DDC), a competitive inhibitor of dopamine-B-hydroxylase, produced a dosage-related depletion of neural NE and impairment of passive avoidance learning in young chicks. Retention was not impaired, however, as shown by normal relearning of the task a day later, when the drug was no longer active. Perhaps, neural NE depletion impairs ability to inhibit responding and, thus, impairs passive or inhibitory avoidance learning indirectly. Alternatively, NE depletion may slow down learning by interfering with consolidation, but if the task is well learned, it is remembered.