Constraints and facilitators to friendships in late late life

This report analyzes friendship patterns of individuals 85 and older, 77% of whom are women. Despite high levels of disability and the loss of age peers, the majority were in frequent contact with friends and still had a close friend. Over 31 months, however, the predictors of friendship involvement changed. At Time 1, mood was most important, but by Time 3, increased disability was most important. Qualitative data describe how the constraints and facilitators lead to changing criteria for friendships in late late life.

Families and support networks among African American oldest-old

This article examines the demographic profile of oldest-old African-Americans who reside in the San Francisco Bay Area. Family life and social support available from adult children, relatives, and friends are explored as they vary by gender. Bivariate analyses indicate that females receive more help from relatives and friends, and males receive more help from immediate family members. Parent and childless respondents were compared for instrumental supports. The childless received support from a variety of helpers, whereas, the parents received help from family or the formal sector. Overall, fewer family members were available to assist the oldest-old with community living, although many were able to redefine relationships and increase the numbers of helpers available to assist them. These findings indicate that the principle of substitution operates among some segments of the older African American population, primarily those who are childless. This pattern was more evident among females than among males.

Differential expectations and realities: race, socioeconomic status and health of the oldest-old

Comparisons by race indicate that African Americans are significantly more disadvantaged than whites in their socioeconomic status. Despite complaints about their situation, however, African Americans report that their situation is better than they had expected. Although they perceive their health as poorer than whites, they are no more disabled functionally, and they have significantly better morale. Within-group correlations find the predictable associations between socioeconomic status and physical, psychological, and social outcomes for both groups. Nevertheless, both qualitative and quantitative data indicate that economic well-being is related to the congruence between expectations and the realities of life in advanced old age, making objective and subjective factors of similar importance.

Introduction: social and cultural diversity of the oldest-old

This introduction describes a volume devoted to a much neglected topic and population, the social and cultural diversity among individuals eighty-five years old and older. Four articles come from the San Francisco 85+

STUDY

1) comparisons by Colleen Johnson between whites and African Americans in socioeconomic status, health, and other outcomes; 2) Barbara Barer's analysis of gender differences in the stressors faced in late-life; 3) Charlotte Perry and Colleen Johnson's examination of the families of oldest-old African Americans; 4) Lillian Troll's analysis of white families. The fifth article by Gloria Clayton on rural/urban differences comes from the Georgia Centenarian STUDY. Finally the volume concludes with a commentary by Leonard Pearlin that places these studies into the broader context of aging research.

Safety of combined oligosaccharide conjugate Haemophilus influenzae type b (HbOC) and whole cell diphtheria-tetanus toxoids-pertussis vaccine in infancy. The Kaiser Permanente Pediatric Vaccine Study Group

The safety of the combined oligosaccharide conjugate Haemophilus influenzae (Hib) type b (HbOC) and whole cell diphtheria-tetanus toxoids-pertussis (DTP) vaccine (Tetramune, HbOC-DTP; Lederle) in infancy was evaluated in 6644 recipients of this vaccine and compared with 3914 recipients of separate injections of whole cell DTP and HbOC vaccines when given as a three dose regimen to infants at 2, 4 and 6 months of age in each group. Of the total number of infants in the study, a subset of 1435 were enrolled into the study and then randomly assigned to receive either the Hib-DPT combined vaccine or the separate components. This subset was used to assess local and systemic side effects which were evaluated utilizing telephone interviews 48 to 72 hours after vaccine. The remaining children in the study population were enrolled in a nonrandomized manner. For these children parents were offered the experimental Hib-DPT vaccine and refusers were given HbOC and DTP. Both of these groups of children as well as the randomized subset described above were used to assess rates of episodes of hospitalization, emergency room utilization and sudden infant death syndrome in HbOC-DTP recipients and children who received HbOC and DTP separately. Immunogenicity was evaluated in 123 children by collection of a single serum sample 30 days after the third dose of HbOC-DTP. The observed immunogenicity was comparable to that observed in other recent studies for HbOC and DTP component antigens. The profile of local and systemic side effects observed was virtually identical to that observed after DTP plus HbOC given separately.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium intakes of Mexican Americans, Cubans, Puerto Ricans, non-Hispanic whites, and non-Hispanic blacks in the United States

OBJECTIVE

To compare dietary calcium intakes from food in Mexican Americans, Cubans, Puerto Ricans, non-Hispanic whites, and non-Hispanic blacks aged 11 through 74 years.

DESIGN

Population survey data from the Hispanic Health and Nutrition Examination Survey and the second National Health and Nutrition Examination Survey were used to calculate calcium intake from a single 24-hour recall. These data were compared by age and sex between the five population groups. Food sources of calcium in the three Hispanic groups were also examined using 24-hour recall data.

SUBJECTS

The sample consisted of 11,773 non-Hispanic whites, 1,728 non-Hispanic blacks, 4,739 Mexican Americans, 1,076 Cubans, and 1,835 Puerto Ricans.

MAIN OUTCOME MEASURES

Mean calcium intake, percentage intake of Recommended Dietary Allowance, and, for Hispanics, food sources of calcium.

STATISTICAL ANALYSES

Means were compared within age and sex groups between the five population groups using a t test.

RESULTS

Calcium intakes from food in the three Hispanic groups were similar to intakes of non-Hispanic whites and higher than intakes of non-Hispanic blacks. Although dairy foods were the main sources of calcium for Hispanics, corn tortillas were important calcium sources among Mexican Americans. Women consumed less calcium than the Recommended Dietary Allowance in all age and racial or ethnic groups.

APPLICATIONS

When assessing calcium intakes of the three Hispanic groups, ethnic differences in food sources of calcium need to be considered. Efforts to increase calcium intake in Hispanics also need to account for ethnic differences.

Electromyographic response of peroneal muscles in surgical and nonsurgical injured ankles during sudden inversion

Because the peroneal muscles are thought to act as a safeguard against lateral ankle injury, it is important to study their function. This study was undertaken to electromyographically assess the latency between sudden unexpected ankle inversion and the start of peroneal muscle activity. Three groups participated in the study, including subjects with lateral ankle sprain rehabilitated nonsurgically (N = 7), sprains rehabilitated following surgery (N = 6), and injury-free ankles (N = 11). Peroneal latency was assessed by dropping the subjects into inversion from a special platform. The platform was designed so that either ankle could be inverted to 35 degrees without warning. The ANOVA revealed no significant latency differences (p > .05) between the three groups. The study suggests that bilateral peroneal latency is unaffected by injury. Although it has been thought that healthy muscles provide a defense against ankle sprain, their latency is not permanently affected by ankle injury or by surgery performed to correct defects from injury. It appears that mechanoreceptor impairment may be rehabilitated and that it is not a factor in ankle injury.

Integrating the twelve-step approach with traditional psychotherapy for the treatment of eating disorders

The treatment outcome literature for anorexia nervosa and bulimia indicates that approximately two thirds of patients treated with brief to moderate length interventions have favorable responses. The remaining one third are more difficult to treat and appear to require longer term and more intensive intervention. These patients can usually be characterized as having more severe Axis I and Axis II comorbidity. This manuscript focuses on a longer term treatment program that integrates psychodynamically oriented psychotherapy with a 12-step component. Specific issues that are addressed include the theoretical dilemma between the two models, advantages and disadvantages of adding a 12-step component, and how various subgroups of patients respond to the model. The clinical viability and preliminary impressions regarding outcome with this model are also offered.

Prevalence of high blood cholesterol among US adults. An update based on guidelines from the second report of the National Cholesterol Education Program Adult Treatment Panel

OBJECTIVE

To estimate the current levels and trends in the proportion of US adults with high blood cholesterol based on guidelines from the second report of the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP II).

DESIGN

Nationally representative cross-sectional surveys.

SETTING/PARTICIPANTS

Data for 7775 participants 20 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey (NHANES III) (data collected from 1988 through 1991) and for 9797 participants 20 through 74 years of age from NHANES II (data collected from 1976 through 1980) were used.

RESULTS

From the data collection period in NHANES II (1976 through 1980) to the period in NHANES III (1988 through 1991), the proportion of adults with high blood cholesterol levels (> or = 240 mg/dL [6.21 mmol bd) fell from 26% to 20%, while the proportion with desirable levels (< 200 mg/dL [5.17 mmol/L]) rose from 44% to 49%. Currently, using the ATP II guidelines and NHANES III data, 40% of all adults 20 years of age and older would require fasting lipoprotein analysis; and 29% of all adults would be candidates for dietary therapy (as compared with 36%, using NHANES II data). Based on 1990 population data, it is estimated that approximately 52 million Americans 20 years of age and older would be candidates for dietary therapy. Assuming that dietary intervention would reduce low-density lipoprotein (LDL) cholesterol levels by 10%, as many as 7% of all adult Americans (approximately 12.7 million) might be candidates for cholesterol-lowering drugs. This estimate reflects approximately 4 million adults with established coronary heart disease, of whom half are aged 65 years and older, and up to 8.7 million adults without established coronary heart disease, of whom up to 3.1 million are aged 65 years and older.

CONCLUSIONS

Substantial progress has been made in reducing the prevalence of high blood cholesterol; yet a large proportion of all adults, approximately 29%, require dietary intervention for high blood cholesterol.

Declining serum total cholesterol levels among US adults. The National Health and Nutrition Examination Surveys

OBJECTIVE

To examine the secular trend in serum total cholesterol levels of the US adult population.

DESIGN

Nationally representative cross-sectional surveys with both an in person interview and a medical examination that included the measurement of blood lipid levels.

SETTING/PARTICIPANTS

Between 6000 and 13,000 adults aged 20 through 74 years examined in each of four separate national surveys during 1960 through 1962, 1971 through 1974, 1976 through 1980, and 1988 through 1991.

RESULTS

Mean serum total cholesterol levels in US adults aged 20 through 74 years have consistently declined over the time period 1960 through 1991. More than half of the decline occurred during the time period 1976 through 1991. This decline occurred across the entire distribution of serum cholesterol levels and in all age-sex groups. High-density lipoprotein cholesterol and very low-density lipoprotein cholesterol levels have not changed, suggesting that the decline in total cholesterol levels is due to a decline in low-density lipoprotein cholesterol levels.

CONCLUSIONS

These results document a continuing and substantial decline in serum cholesterol levels among US adults. They suggest that public health programs, designed to reduce cholesterol levels, are proving successful. The observed downward trend in serum cholesterol levels has coincided with a continuing decline in coronary heart disease mortality. These observations suggest that the Healthy People 2000 goal of reducing the mean serum cholesterol level of US adults to no more than 200 mg/dL (5.17 mmol/L) is attainable.

Issues in the long-term evaluation of diet in longitudinal studies

Longitudinal studies are very useful for studying diet/disease relationships. The fundamental components of a longitudinal study are that: 1) data are collected for two or more distinct time periods; 2) the subjects are the same or comparable from one time period to the next; and 3) data are compared between or among time periods in the analysis. A longitudinal study is often assumed to be synonymous with a cohort study, but there are at least four possible definitions for a longitudinal study. While focusing on cohort studies, the paper describes the nature of longitudinal studies, including a discussion of how the different definitions differ from a cohort study and a set of important assumptions necessary to cohort studies. It also highlights some of the major issues associated with such studies, including the selection of a dietary survey methodology; data collection issues in multicultural, multilingual societies; the importance of nutrient databases; measurement error and misclassification in nutrient intake and energy adjustment.

Management of catastrophic neonatal midgut volvulus with a silo and second-look laparotomy

The case of a neonate with midgut volvulus and severe intestinal ischemia extending from the ligament of Treitz to the midtransverse colon is presented. Management consisted of abdominal silo application at the initial exploration to obviate the adverse physiological consequences of increased intraabdominal pressure from reperfusion edema of the intestine. The majority of the intestine was salvaged, and a short segment of ileum was resected. This method of treatment resulted in optimal ventilatory status, renal function, and cardiac performance. The advantages of temporary prosthetic wound coverage in selected cases of midgut volvulus include greater physiologic stability through the avoidance of "intraabdominal hypertension" and the ability to monitor the status of the intestine at the bedside.

The effect of TNFa on bradykinin receptor binding, phosphatidylinositol turnover and cell growth in human A431 epidermoid carcinoma cells

In this study, we examined the effect of TNFa on bradykinin (BK) B2 receptor binding and function in human A431 epidermoid carcinoma cells. [3H]BK binds to a single class of receptors on A431 cells in a saturable and reversible manner. A binding affinity (KD) of 3.0 +/- 0.3 nM (n = 4) and a Bmax of 151 +/- 14 fmols/10(6) cells, representing approximately 90,000 BK receptors per cell, was observed. The rank order of potency for BK agonist peptides indicates that the A431 BK receptor appears to be of the B2 subtype. When A431 cells were incubated with TNFa (10 ng/ml) for 48 h prior to BK binding, a significant decrease in the number of BK receptors compared to control was observed. TNFa did not influence the affinity of BK binding to A431 cells and direct addition of TNFa to the binding assay did not effect BK binding. BK-stimulated IP1 formation appeared to be increased in TNFa treated cells compared to control whereas histamine-stimulated IP1 formation was not influenced. Both control and TNFa treated cells were greater than 95% viable. However, TNFa treated cells were blocked in the G1 phase of the cell cycle resulting in a decrease in DNA synthesis. This may be one mechanism for the TNFa-induced decrease in BK receptors in A431 cells.

Loss of heterozygosity on chromosome 11 in sporadic gastrinomas

Gastrinomas are pancreatic endocrine neoplasms that arise either sporadically or are inherited as part of the multiple endocrine neoplasia type I syndrome (MENI). Loss of heterozygosity (LOH) in the region flanking the MENI gene at chromosome 11q13 has been documented in a few sporadic and familial pancreatic endocrine tumors, but not previously in sporadic gastrinomas. It has therefore been suggested that gastrinomas develop by a mechanism different from other tumors associated with the MENI syndrome. We report LOH on chromosome 11 in 5 of 11 sporadic gastrinomas. Four of these tumors have LOH for markers flanking the MENI region. Molecular evaluation of segments of chromosomes 3, 13, and 17 known to contain cloned or putative tumor suppressor genes fail to show LOH except at one locus in one tumor. These data suggest that a tumor suppressor DNA segment exists at 11q13 that may be involved in the development of sporadic gastrinomas.

Estimation of genetic parameters for wool fiber diameter measures

Genetic and phenotypic correlations and heritability estimates of side, britch, and core diameters; side and britch CV; side and britch diameter difference; and clean fleece weight were investigated using 385 western white-faced ewes produced by 50 sires and maintained at two locations on a selection study. Data were analyzed using analysis of variance procedures, and effects in the final model included breed of sire-selection line combination, sire within breed-selection line, and location. Heritabilities were estimated by paternal half-sib analysis. Sires within breed-selection line represented a significant source of variation for all traits studied. Location had a significant effect on side diameter, side and britch diameter difference, and clean fleece weight. Age of ewe only affected clean fleece weight. Phenotypic and genetic correlations among side, britch, and core diameter measures were high and positive. Phenotypic correlations ranged from .68 to .75 and genetic correlations ranged from .74 to .89. The genetic correlations between side and britch diameter difference and side diameter or core diameter were small (-.16 and .28, respectively). However, there was a stronger genetic correlation between side and britch diameter difference and britch diameter (.55). Heritability of the difference between side and britch diameter was high (.46 +/- .16) and similar to heritability estimates reported for other wool traits. Results of this study indicate that relatively rapid genetic progress through selection for fiber diameter should be possible. In addition, increased uniformity in fiber diameter should be possible through selection for either side and britch diameter difference or side or britch CV.

Effects of skirting on processing characteristics of Targhee wool

Ninety mature Targhee ewes were randomly allocated to nine lots. Lots were randomly assigned to three fleece preparation treatments: 1) nonskirted (control); 2) bellies removed, in which bellies and topknots were removed on the shearing floor; and 3) skirted, in which bellies and topknots were removed and remaining fleece was thrown on a table and lightly skirted. Bellies and topknots composed about 6 to 7% of the fleece weight. An additional 6.6% was removed when fleeces were skirted. Top fiber diameters were not affected (P greater than .10) by skirting. Although not significant (P greater than .10), percentage yield, vegetable content, percentage of noilage, top fiber length, and yellowness indexes tended to be most desirable for skirted lots and least desirable for unskirted lots. Lots with bellies removed were intermediate. Removal of bellies reduced vegetable contamination by 8.4%, with an additional reduction of about .5% by further skirting. Skirting reduced the number of fibers less than 25.4 mm (P less than .10) by 42%. Minimal colored fiber contamination of top was observed. One colored fiber per 15 g of top was detected in two lots of the treatment with bellies removed. All other lots contained no colored fibers. All wools evaluated were well below industry limits set for use in high-quality white or pastel fabrics. All skirted lots of wool evaluated in this study had improved processing characteristics for all processing traits evaluated.

Family functioning in late late life

This study of 150 individuals, 85 years and older, focused on their families and social networks. Using both structured and open-ended questions, we explored the extent to which the family functions as a source of support for the oldest old. The findings indicate that those with children are significantly more active with all relatives, most likely because children link them to grandchildren, great-grandchildren, and their relatives by marriage. For the 30 percent who are childless and unmarried, other relatives are not usually active providers of support, a finding which suggests that the principle of substitution does not operate effectively for this age group. Case studies illustrate the variations in family functioning in the support of their oldest members.

Characterization of Receptors for Substance P in Human Astrocytoma Cells: Radioligand Binding and Inositol Phosphate Formation

UC11 cells, derived from a human astrocytoma, have a high density of functional substance P receptors. Radioligand binding studies were conducted with the highly selective neurokinin-1 receptor ligand [3H][Sar9,Met(O2)11]-substance P. Kinetic binding experiments conducted at 4 degrees C yielded an association rate constant k1 of 1.86 x 10(7) M-1 min-1, a dissociation rate constant k-1 of 0.00478 min-1, and a calculated kinetic KD of 257 pM. Saturation binding experiments yielded average values of KD = 447 +/- 103 pM, Bmax = 862 +/- 93 fmol/mg of protein. This Bmax corresponds to more than 150,000 binding sites/cell. Competition binding experiments with unlabeled [Sar9,Met(O2)11]-substance P yielded average values of KD = 491 +/- 48 pM and Bmax = 912 +/- 67 fmol/mg of protein. In [3H]inositol-labeled cells, substance P induced a robust inositol phosphate formation. Inositol trisphosphate levels increased as much as 20-fold within approximately 15 s of addition of substance P. This inositol trisphosphate formation was transient and had returned to baseline within the first 60-120 s. Inositol monophosphate formation, however, was linear for at least 2 h. Structure activity data on binding and inositol monophosphate formation confirmed the presence of a neurokinin-1 receptor subtype in these cells. Thus, the UC11 cell should be a useful model cell for delineating the physiological role of substance P receptors in astrocytes.

Tumor necrosis factor and interleukin-1 down-regulate receptors for substance P in human astrocytoma cells

This study examined the influence of cytokines on substance P (SP) receptors (NK1 subtype) in the human astrocytoma cell line UC11. Following trypsinization and passage, the density of SP receptors in these cells was rather low but gradually increased several fold over the course of a few days in culture. Frequent replacement of the growth medium enhanced the density of receptors even more, suggesting that growth factors in the culture medium may determine the levels of receptor. Exposure of the cells to sub-nanomolar concentrations of tumor necrosis factor (TNF alpha) or interleukin-1 beta (IL1 beta), but not interleukin-2 or interleukin-6, decreased the density of SP receptors. This was accompanied by a decrease in the ability of SP to stimulate inositolphosphate formation. The ability of histamine to activate inositolphosphate formation was not influenced by the cytokines. The decrease in SP receptor density was readily reversible on washout of the cytokines. The EC50 for TNF alpha was approximately 0.5 ng/ml, the EC50 for IL1 beta was approximately 0.1 ng/ml. Radioligand binding studies with [125I]TNF alpha indicated the presence of a low density of high affinity binding sites for this ligand: Kd = 2.5 +/- 0.6 ng/ml, Bmax = 14.8 +/- 2.7 fmol bound/mg protein (assuming trimeric form of ligand bound). The most likely explanation for the cytokine effect is an inhibition of the synthesis of new receptors.

Prediction of responses in milk constituents to changes in the nutrition of dairy cows

Milk quotas, based on an average fat content, severely limit milk production on UK farms. Predictions of the time-course of lactation are incorporated into most computerized herd management programs but these models take no account of food inputs, body weight change or milk composition. Dynamic models are generally used to simulate metabolic pathways and, as such, have little direct relevance to commercial milk production. Dynamic models can be converted to an adaptive-predictive model that partitions food energy into milk and non-milk constituents. This paper reports the development of an adaptive-predictive model to partition food into milk and non-milk components. Additional functions further partition milk energy into the principal constituents, fat, protein and lactose.

A multipoint linkage map of the distal short arm of the human X chromosome

The distal portion of the short arm of the human X chromosome (Xp) exhibits many unique and interesting features. Distal Xp contains the pseudoautosomal region, a number of disease loci, and several cell-surface markers. Several genes in this area have also been observed to escape X-chromosomal inactivation. The characterization of new polymorphic loci in this region has permitted the construction of a refined multipoint linkage map extending 15 cM from the Xp telomere. This interval is known to contain the loci for the diseases X-linked ichthyosis, chondrodysplasia punctata, and Kallmann syndrome, as well as the cell-surface markers Xg and 12E7. This region also contains the junction between the pseudoautosomal region and strictly X-linked sequences. The locus MIC2 has been demonstrated by linkage analysis to be indistinguishable from the pseudoautosomal junction. The steroid sulfatase locus has been mapped to an interval adjacent to the DXS278 locus and 6 cM from the pseudoautosomal junction. The polymorphic locus (STS) DXS278 was shown to be informative in all families studied, and linkage analysis reveals that the locus represents a low-copy repeat with at least one copy distal to the STS gene. The generation of a multipoint linkage map of distal Xp will be useful in the genetic dissection of many of the unique features of this region.

Response of 7- to 15-month-old infants to sequential immunization with Haemophilus influenzae type b-CRM197 conjugate and polysaccharide vaccines

OBJECTIVE

To evaluate the immunologic potential of infants 7 to 15 months of age to respond to Haemophilus influenzae type b polysaccharide vaccine following immunization with H influenzae b oligosaccharide-CRM197 conjugate vaccine.

STUDY DESIGN

One hundred seventy-one infants, aged 7 to 15 months, were consecutively and alternatively assigned to one of three immunization protocols. Group 1 (n = 71) received three doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine, group 2 (n = 47) received two doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine followed by one dose of H influenzae type b polysaccharide vaccine, and group 3 received one dose of H influenzae b oligosaccharide-CRM197 conjugate vaccine followed by two doses of H influenzae type b polysaccharide vaccine. Immunizations were given on day 0 and at 2 months and 6 months. Anti-H influenzae type b polysaccharide antibody levels were measured on day 0 and 2, 3, 6, 7, and 12 months after the study began.

RESULTS

Haemophilus influenzae type b polysaccharide vaccine given as a second dose stimulated an antibody rise but did so less effectively than H influenzae b oligosaccharide-CRM197 conjugate vaccine. Two doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine were highly immunogenic; geometric means were 31 and 35 micrograms/mL in the 7- to 11-month and 12- to 15-month age groups, respectively. Following two doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine, both immunization protocols resulted in (1) equally high geometric mean antibody levels 1 month after immunization and (2) similar geometric mean antibody levels 6 months after immunization.

CONCLUSIONS

Haemophilus influenzae b oligosaccharide-CRM197 conjugate vaccine induces antibody levels that would be expected to protect infants from initial invasion and primes the immune system for an anamnestic response. Our data indicate that if a booster immunization is needed, H influenzae type b polysaccharide vaccine could be an alternative to H influenzae b oligosaccharide-CRM197 conjugate vaccine.

Dihydropyridine receptor binding sites in the cardiomyopathic hamster heart are unchanged from control

An increase in the number of voltage dependent calcium channels has been implicated in the overload of calcium found in cardiac tissue of the cardiomyopathic hamster. We examined the binding of [3H]-(+)PN200110 to dihydropyridine receptors in cardiac muscle membranes from TO cardiomyopathic hamsters. When compared to random bred controls, there were no differences in either the Bmax or the KD for [3H]-(+)PN200110 binding using homogenates from 35 to 41-day-old TO cardiomyopathic hearts. In 8 to 9-month-old myopathic animals there were only small decreases in Bmax with no change in KD. We suggest that the calcium overload observed in cardiomyopathic hamster heart may not be due to an increased density of calcium channels as estimated by high affinity dihydropyridine receptor binding sites.

Hispanic Health and Nutrition Examination Survey: methodological considerations

The Hispanic Health and Nutrition Examination Survey (HHANES) was the first special population survey undertaken by the National Center for Health Statistics. The HHANES was designed to assess the health and nutritional status and needs of Mexican Americans, mainland Puerto Ricans and Cuban Americans. Data were collected using five data collection techniques: direct physical examinations, diagnostic testing, anthropometry, laboratory analyses, and interviews. Unlike other surveys conducted by the National Center for Health Statistics, the HHANES was not designed as a national survey. The HHANES was a survey of three Hispanic subgroups of the population in selected areas of the United States with a survey universe that included approximately 76 percent of the 1980 Hispanic-origin population in the United States. This article discusses statistical issues that should be addressed by researchers when analyzing HHANES data. Specifically, analysts need to account for the complex sample design, nonresponse bias, potential non-coverage bias, and the regional nature of the HHANES sample.

Families and networks among older inner-city blacks

These research findings compare the support networks of inner-city blacks and whites, 65 years and older, who were selected from hospital medical clinics. Both blacks and whites who are in need of help use formal supports. Blacks, however, have more active support networks than do whites despite the low incidence of support from spouses and children. These social resources result from mechanisms in black families that expand network membership through the creation of fictive kin.

Safety and immunogenicity of Haemophilus influenzae type b oligosaccharide-CRM197 conjugate vaccine in infants aged 15 to 23 months

A total of 268 infants aged 15 to 23 months received one dose of a vaccine composed of Haemophilus influenzae type b oligosaccharides covalently linked to the nontoxic diphtheria toxin variant CRM197 (HbOC; HibTITER). Side effects associated with vaccination were infrequent, transient, and mild. One month after a single vaccination, the anti-H influenzae type b capsular polysaccharide antibody concentration rose from a geometric mean prevaccination level of 0.20 microgram/mL to 13.77 micrograms/mL. Of these infants, 99% had a postvaccination level greater than or equal to 1.00 microgram/mL, a level associated with long-term protection. The immune response was long-lived: all of the children who were monitored 17 to 27 months after vaccination had concentrations greater than or equal to 1.00 microgram/mL. The anti-H influenzae type b capsular polysaccharide antibody generated was predominantly of the IgG isotype and IgG1 subclass. The immune sera had bactericidal activity in vitro and conferred passive protection in the infant rat meningitis model.

Within-person variance in biochemical indicators of iron status: effects on prevalence estimates

The effect of within-person variance on prevalence estimates from population distributions based on a single measurement was examined for hematologic and iron-status indicators collected in the Hispanic Health and Nutrition Examination Survey (HHANES). Within-person to between-person variance ratios (W:Bs) were estimated for 11 indicators by using data from 80 persons who provided blood twice in HHANES. Distributions of selected iron-status indicators from 20-44-y-old Mexican American females from HHANES were adjusted for within-person variance by using the W:B estimates, and prevalences of low values based on the original and adjusted distributions were compared. W:B were less than 1 for the majority of the indicators. Nonetheless, prevalences of low values from the original distributions were inflated when commonly used cutoff values were applied. Within-person variance in serum analytes needs to be controlled when the prevalence of a condition in populations is assessed.

Folate status of Mexican American, Cuban, and Puerto Rican women

The objective of this study was to estimate the prevalence of low serum and red blood cell (RBC) folate values of Mexican American (MA), Cuban (C), and Puerto Rican (PR) women examined in the Hispanic Health and Nutrition Examination Survey, 1982-1984. Serum and RBC folate were determined for all women aged 18-44 y by use of a radio-assay kit. The percent of women with low serum folate (less than 6.8 nmol/L) was 11.9% for MA, 10.1% for C, and 8.1% for PR. The prevalence of low concentrations of RBC folate (less than 363 nmol/L) was 7.8%, 16.7%, and 13.6% for MA, C, and PR, respectively. The percentages of women with reduced tissue stores of folate were 4.3% for MA, 6.0% for C, and 4.0% for PR. Years of education completed and poverty status did not significantly affect folate concentrations; however, the prevalence of low folate concentrations among users of vitamin or mineral supplements was significantly lower than it was among nonusers in selected subgroups.

Effect of dose and route of administration of thyroid releasing hormone (TRH) on the concentration of prolactin (PRL) and thyroxine (T4) in cyclic gilts

Our objective was to examine the ability of thyroid releasing hormone (TRH) to stimulate not only the release of the thyroid hormones, but also prolactin (PRL) in the female pig. An experiment was conducted to determine the effect of dose and route of administration of TRH on the concentration of PRL and thyroxine (T4) in cyclic gilts. Six gilts were injected with 0, 5, 25, 125, and 625 micrograms TRH and fed 0, 5, 2.5, 12.5 and 62.5 mg TRH. Gilts received TRH once daily. During the 10-day treatment period, route of TRH administration alternated between i.v. injection and feeding. The dose of TRH progressed from the lowest to the highest. Blood samples were taken prior to TRH injection and thereafter at 15-min intervals for 3 hr. Sampling continued for an additional 3 hr at 30-min intervals when TRH was fed. Concentrations of PRL and T4 were determined by radioimmunoassay. Intravenous injection of gilts with 125 and 625 micrograms TRH resulted in an increase in PRL from 0 to 15 min (P less than .05). All doses of TRH given i.v. elevated T4 over a 2-hr period (P less than .01). TRH failed to increase PRL when TRH was fed (P greater than .5). The feeding of 62.5 mg TRH elevated T4 from 0 to 6 hr (P less than .01). Thus, TRH injection increased PRL rapidly and T4 gradually. When TRH was fed, only a gradual elevation in T4 was observed. We conclude that TRH can elicit the release of both PRL and T4 in the cyclic gilt, but magnitude and duration of the PRL and T4 response depends on the dose and route of TRH administration.

Rationale of feeding systems for lactating dairy cows

Manipulations of the lactation cycle are achieved through nutritional regimens and generally result in a restriction of the physiological lactation cycle. Most models of lactation used in management programmes only describe the average time course of lactation for groups of cows on a given feeding regimen. This is inadequate for the variety of feeding systems in use on British farms. In the present paper several existing models of lactation have been critically evaluated. An integral equation approach has been developed to rationalize experimental observations and currently accepted biological concepts.

Safety and immunologic response to Haemophilus influenzae type b oligosaccharide-CRM197 conjugate vaccine in 1- to 6-month-old infants

A Haemophilus influenzae type b oligosaccharide-CRM197 conjugate (HbOC) vaccine was evaluated for safety and immunogenicity in 432 infants 1 to 6 months of age. In a multicenter study involving 10 sites in six states, infants were vaccinated with three 10-micrograms doses of HbOC at 2-month intervals. Side effects associated with vaccination were mild, transient, and occurred in fewer than 2% of the subjects. More than 90% of infants of all ages responded after two doses, and more than 98% had anti-H influenzae type b capsular polysaccharide (HbPs) antibody levels greater than or equal to 1 microgram/mL after three doses. One month after the third vaccination, the geometric mean anti-HbPs antibody levels were 16.84, 26.23, and 29.11 in infants initially vaccinated at 1 to 2, 3 to 4, and 5 to 6 months of age, respectively. A long-term antibody response was observed; more than 80% of these infants had anti-HbPs levels greater than or equal to 1 microgram/mL at 2 years of age. The HbOC generated an immune response characteristic of a protein antigen; IgG anti-HbPs antibodies of IgG1 subclass predominated and the response could be boosted. The immune sera killed H influenzae type b when evaluated in an in vitro bactericidal assay. The data indicate that HbOC safely primed and boosted the immune system of young infants, providing long-lasting protective levels of anti-HbPs antibodies.

Histamine receptors in human fibroblasts: inositol phosphates, Ca2+, and cell growth

Histamine stimulated inositol phosphate formation by human skin fibroblasts. The effect of histamine was reduced but still readily apparent in the absence of extracellular Ca2+. Histamine caused a transient increase in intracellular free Ca2+ as detected by indo-1 and fura-2 fluorescence studies on cell populations and on individual cells. Similar increases were observed in the absence of extracellular Ca2+, indicating that the effect was primarily due to mobilization of Ca2+ from intracellular stores, presumably by inositol trisphosphate (IP3). The effects of histamine on phosphoinositide metabolism and intracellular Ca2+ were inhibited by pretreatment of the cells with phorbol esters, suggesting that the histamine receptor in fibroblasts is subject to feedback regulation by protein kinase C. Histamine inhibited the incorporation of [3H]-thymidine into DNA. The effects of histamine on inositol phosphate formation, intracellular Ca2+, and thymidine incorporation were blocked by the H1 receptor antagonist mepyramine. Our results indicate that human skin fibroblasts have H1 receptors coupled to the formation of inositol phosphates and mobilization of intracellular Ca2+. We suggest that this H1 receptor also mediates a block of the cell cycle and that histamine may play a physiological role in the regulation of fibroblast proliferation.

A critique of the caregiving literature

In this critical review of the recent caregiving literature, we identify several methodological problems. Specifically noted are the variable and often confusing definitions of the caregiver, the lack of specification of needs, overrepresentation of self-selected samples, and the absence of attention to the total support network. We conclude that future researchers should focus on the total support process in later life, rather than on a single caregiver, so that policy can best be designed to mesh the informal and formal support systems.

Inhibition of human skin fibroblast proliferation by histamine and phorbol esters is mediated by protein kinase C

The proliferation of human skin fibroblasts in culture was examined using a [3H]thymidine incorporation assay. Histamine inhibited thymidine incorporation with an IC50 of about 0.2 microM. This effect was blocked by the H1 receptor antagonist mepyramine but not by the H2 receptor antagonist cimetidine. Protein kinase C activators, including several phorbol esters and mezerine, also inhibited thymidine incorporation. The IC50 for beta-phorbol 12,13-didecanoate was less than 0.1 nM. The alpha-isomer of this compound was inactive. Long-term treatment of cells with the beta-isomer eliminated the ability of both histamine and phorbol ester to inhibit thymidine incorporation, presumably due to downregulation of protein kinase C. Our results suggest that histamine H1 receptors are linked to activation of protein kinase C and that activation of this enzyme leads to an inhibition of cell proliferation.

The Kmod blood group phenotype in a healthy individual

This report describes a healthy blood donor whose red cells have weakened expression of Kell blood group antigens. Kell antigen activity could not be detected by flow cytometric analysis and was demonstrable only by sensitive serologic techniques. As with normal-strength Kell antigens, reactivity could be abolished by treatment with 2-aminoethylisothiouronium bromide (AET). The donor's red cells have Kx antigen activity. Other commonly tested blood group antigens (MNSs, Rh, P1, Lewis, Duffy, and Kidd systems) appear normal. Clinical and serologic examination showed that this case is different from previously described examples of modified Kell expression. The propositus's phenotype has remained unchanged for 19 months, which suggests that it is not a transient condition. However, family studies provide no evidence that it is inherited. A 93-kD protein, which reacted weakly by Western blot with rabbit antibody to Kell protein, was isolated from the propositus's red cells by immunoprecipitation. This finding was not reproduced in subsequent studies, which suggests that the quantity of Kell protein recovered was at the threshold level detectable by the technique used. The red cell phenotype is categorized as Kmod, of which this is the first example reported in a healthy individual.

Development of human embryonic and fetal dermal vasculature

This report summarizes recent advances in the understanding of the structure and organization of the microvasculature in developing human skin. Previous observations suggested that the skin contains no blood vessels as late as eight weeks estimated gestational age (EGA). Computer reconstructions, in conjunction with light and transmission electron microscopy (TEM), however, demonstrated that specimens as young as 35-45 d show a level of vascular complexity previously unknown. The computer reconstructions showed that the vasculature was organized in one or two planes parallel to the epidermis. A simple, single plane was evident in specimens 40-50 d EGA, whereas specimens 50-75 d EGA showed two planes. Fewer vessels were continuous throughout the tissue sample in the younger specimens compared with the older specimens. Superior views highlighted the continuities and connections of vessels. The younger specimens showed more discontinuous segments of vessels when compared with the network established in the older specimens. In the earliest specimens examined morphologically (35-40 d), simple, capillarylike vessels were morphologically identifiable in presumptive dermis. The samples studied by TEM revealed detailed structure of the vessel wall including extreme attenuations and projections, plasmalemmal vesicles, and junctions similar to adult endothelial cells. Little or no basal lamina surrounded the vessel. The basal lamina first appeared in the form of amorphous deposits and eventually thickened and became continuous. By the end of the first trimester, the basal lamina still lacked the organization of adult cutaneous arterial and venous segments. These findings suggest that the major vascular organization of the dermis is defined in the first trimester of development.

Comparison of human and chimpanzee Kell blood group systems

Kell antigens on chimpanzee (Pan troglodytes) red cells were determined using specific human alloimmune and murine monoclonal antibodies. After avoidance of interspecies reactions, chimpanzee red cells were found to react with most Kell system antibodies. The chimpanzees had phenotypes similar to those of humans. The main difference was that all of 27 chimpanzee red cell samples tested were of the K:6, -7, phenotype, while in humans most are K:-6, 7. The most common chimpanzee Kell blood group phenotype was K:-1,2,-3,4,5,6,-7,11,12,13,14, 15,18,19,22. Murine monoclonal anti-K2 and -K14 immunoprecipitated a 97-kD protein from chimpanzee red cells and a 93-kD protein from human red cells. Enzymatic deglycosylation yielded proteins of about 79 kD for humans and 77 kD for chimpanzees. Both human and chimpanzee Kell proteins reacted equally well on Western blots with polyclonal rabbit antibody to human Kell protein, which indicated close homology.

Effect of change of diet on the mineral composition of rumen fluid, on magnesium metabolism and on water balance in sheep

1. The effects of four diets on water intake, rumen fluid outflow-rate, rumen pH and mineral metabolism were studied in wether sheep. The diets were barley and hay, flaked maize and hay, dried grass and frozen grass. 2. Experimental periods were of 12 d duration, and plasma magnesium concentrations were lower at the end of treatment periods when the grass diets were given and were significantly different (P less than 0.05) at 11.00 and 20.45 hours. Also, the concentration was significantly lower with the dried-grass diet than with the frozen-grass diet (P less than 0.05). 3. The concentration of Mg in rumen fluid centrifuged at 30,000 g (ultracentrifuged) varied with the diet. Maximum concentrations (tmax) were reached 4 h later on the grass diets than on the hay and concentrate diets. In the latter case tmax coincided with that for calcium, potassium, chloride and ammonia. At this time sodium and phosphate were at a minimum. The concentration of Mg in ultracentrifuged rumen fluid was negatively correlated (r -0.89) with pH, which was significantly higher (P less than 0.01) at all times on the grass diets. This relation was also reflected in the apparent availability of Mg. 4. Total water intake on the frozen grass was about twice that on the barley and hay diet. The outflow rate of liquid from the rumen was higher on the frozen grass than on the other three diets. 5. The proportion of absorbed Mg excreted in urine was significantly influenced by diet.

Iron status: prevalence of impairment in three Hispanic groups in the United States

Little is known about the iron status of Hispanic groups in the United States. Data from the Hispanic Health and Nutrition Examination Survey were used to estimate the prevalence of impaired Fe status for persons aged 5-74 y from three Hispanic groups: Mexican Americans (MAs), Cubans, and Puerto Ricans; prevalences were also calculated for non-Hispanic whites (NHWs) and non-Hispanic blacks (NHBs) using data from the second National Health and Nutrition Examination survey. A three-variable model called the MCV model was used to assess impaired Fe status. Prevalences based on the MCV model did not differ between Hispanic groups. Differences between Hispanics and non-Hispanics occurred only among 20-44-y-old females, where MAs had a higher prevalence than NHWs or NHBs. With this exception, these Hispanic groups do not appear to be at greater risk of impaired Fe status than non-Hispanics.

Regional chemotherapy in an experimental model of Wilms' tumor in rats

A s.c. experimental model of Wilms' tumor in rats was used to compare the effects of intratumoral treatment with vincristine plus actinomycin D to i.v. treatment with these chemotherapeutic drugs. The Wilms' tumor model is a fast-growing solid tumor that has been shown to be resistant to traditional clinical treatment procedures used for Wilms' tumor in man. Injection of the chemotherapeutic drugs directly into the tumor mass was found to be more effective than i.v. therapy in causing long-term remission of the tumor. Intratumoral therapy was also less toxic to the animals than i.v. therapy when measured by post-treatment survival rates and weight loss during the 1st week following treatment. However, intratumoral treatment caused an initial fibrosis of the tumor tissue, which resulted in a slower rate of absorption of the resultant fibrotic tumor mass than was seen in tumors treated i.v. Also, intratumoral injection resulted in necrosis of the overlying skin, which healed as the fibrotic tumor tissue was absorbed. Intratumoral treatment of a cervical tumor was found to cause the remission of a second major tumor mass located at some distance from the initial injection (i.e., in the lumbar region). No significant benefits were noted when dimethylsulfoxide (DMSO) was used in place of aqueous mannitol as a vehicle to deliver the chemotherapeutic agents. There was a significant correlation between the drug dose-to-tumor-size ratio (D/T ratio) and the effectiveness of the chemotherapy. When this ratio was high enough, a single treatment with a combination of vincristine and actinomycin D usually resulted in total remission of the experimental Wilms' tumor in response to either intratumoral or i.v. therapy.

Embedding prolene for the development of fiducial markers

A simple, inexpensive method is described for embedding Prolene with tissue samples to provide landmarks for fiducial points to align serial sections in tissue reconstructions. Prolene is a monofilament suture material that can be easily sectioned with diamond knives to provide circular markers in each section. The sections are photographed, the negatives are projected through an enlarger and the contours, Prolene circles, and scratches from the diamond knife are traced onto paper. These landmarks establish a framework for assigning fiducial points that are necessary for the correct alignment of the contours. No special equipment is needed for embedding the Prolene and the method is adaptable for both automated and nonautomated computer systems. An example of this method for tissue alignment is given using embryonic limb tissue to determine the spatial organization of developing blood vessels as demonstrated by computer reconstruction.

Blood grouping with the Olympus PK7100 testing system

The Olympus PK7100, an automated microtitre blood typing machine, identifies, aliquots, and dilutes samples, adds reagents, photometrically detects agglutination, and records reaction results, with a throughput of 240 samples/h. A total of 20,147 donors was tested in parallel with the Groupamatic 360. Of these, 207 could not be ABO typed after two runs. Three samples typed as B by the Olympus were found to be A2B. Seventy-seven could not be typed for D after two runs. Of these, 55 were Rh positive and 22 negative. The Olympus identified 37 of 48 Du positive samples as Rh positive, while it typed three as Rh negative, and eight as 'uncertain'. None of these samples was identified as Rh positive by the Groupmatic 360. The Olympus PK7100 is accurate, reliable, easy to operate, and capable of high throughput with minimal operator intervention.