Correlation of quantitative computed tomographic subchondral bone density and ash density in horses.

The purpose of this study was to compare subchondral bone density obtained using quantitative computed tomography with ash density values from intact equine joints, and to determine if there are measurable anatomic variations in mean subchondral bone density. Five adult equine metacarpophalangeal joints were scanned with computed tomography (CT), disarticulated, and four 1-cm(3) regions of interest (ROI) cut from the distal third metacarpal bone. Bone cubes were ashed, and percent mineralization and ash density were recorded. Three-dimensional models were created of the distal third metacarpal bone from CT images. Four ROIs were measured on the distal aspect of the third metacarpal bone at axial and abaxial sites of the medial and lateral condyles for correlation with ash samples. Overall correlations of mean quantitative CT (QCT) density with ash density (r=0.82) and percent mineralization (r=0.93) were strong. There were significant differences between abaxial and axial ROIs for mean QCT density, percent bone mineralization and ash density (p<0.05). QCT appears to be a good measure of bone density in equine subchondral bone. Additionally, differences existed between axial and abaxial subchondral bone density in the equine distal third metacarpal bone.

Factors associated with use of preventive dental and health services among U.S. adolescents.

PURPOSE: To examine adolescents' use of preventive medical and dental services and its relationship to demographic characteristics and other variables reflecting access to and need for care. METHODS: Self- and parent-reported data from a sample of 5644 adolescents aged 11 to 21 years from the National Longitudinal Study of Adolescent Health (Add Health). Variables studied include the influence of both the adolescents' demographic and socioeconomic characteristics (age, race/ethnicity, place of birth, acculturation, insurance status, and perception of health), as well as those of their parents (race/ethnicity, income, level of education, place of birth) on their lifetime use and use within the past year of medical and dental services. Bivariate and logistic regression analyses were conducted using SAS and SUDAAN. RESULTS: Approximately 32% of respondents had not had a physical examination in the year before the survey, and the same percentage had not had a dental examination. Approximately 2% reported never having had either a physical or a dental examination. Logistic regression reveals that lack of insurance, low family income, and low parental education level are significantly associated with the lack of preventive medical care. Lack of an annual dental visit was associated with male gender; black, Hispanic, or mixed race/ethnicity; and lack of insurance. Never having had a dental visit was the only dependent variable found to be associated with place of birth. CONCLUSIONS: Health insurance and family income are most consistently related to adolescents' use of preventive medical and dental care. However, the relationship between lack of dental care and place of birth emphasizes the need to improve access to dental services for immigrant teens. These findings are particularly relevant as states design systems of care for adolescents under the State Children's Health Insurance Program.

Brachial flow-mediated vasodilator responses in population-based research: methods, reproducibility and effects of age, gender and baseline diameter.

BACKGROUND: Brachial artery ultrasound has been proposed as an inexpensive, accurate way to assess cardiovascular risk in populations. However, analysis and interpretation of these data are not uniform. METHODS: We analysed the relationship between relative and absolute changes in brachial artery diameter in response to flow-mediated dilation and age, gender and baseline diameter among 4,040 ultrasound examinations from subjects aged 14 to 98 years. RESULTS: Reproducibility studies demonstrated intra- and interreader and intrasubject correlations from 0.67 to 0.84 for repeated measures of per cent change in diameter. Per cent change in diameter after flow stimulus was 3.58 +/- 0.10% (mean +/- standard deviation). Corresponding values for baseline diameter and absolute change in diameter were 4.43 +/- 0.87 mm and 0.15 +/- 0.01 mm, respectively. Baseline diameter and its variance were inversely related to per cent change in diameter (P< 0.001). In contrast, absolute change in diameter was more uniform throughout the range of baseline diameters. Baseline diameter was directly related, and per cent change in diameter inversely related, to age (P < 0.001 for all three measures). Time to maximum vasodilator response increased with age (P < 0.001). Women (n=2,315) had significantly larger per cent change in diameter than men (n=1,725) (P < 0.001). However, after adjustment for age and baseline diameter, per cent and absolute change were 5% smaller in women than men (P < 0.05 for both). In multivariate analysis, age was overwhelmingly the most important determinant of absolute change in diameter (P < 0.001). CONCLUSIONS: Automated analysis of brachial flow-mediated vasodilator responses is both feasible and reproducible in large-scale clinical and population-based research.

Expression of axolotl DAZL RNA, a marker of germ plasm: widespread maternal RNA and onset of expression in germ cells approaching the gonad.

How germ cell specification occurs remains a fundamental question in embryogenesis. The embryos of several model organisms contain germ cell determinants (germ plasm) that segregate to germ cell precursors. In other animals, including mice, germ cells form in response to regulative mechanisms during development. To investigate germ cell determination in urodeles, where germ plasm has never been conclusively identified, we cloned a DAZ-like sequence from axolotls, Axdazl. Axdazl is homologous to Xdazl, a component of Xenopus germ plasm found in the vegetal pole of oocytes and eggs. Axdazl RNA is not localized in axolotl oocytes, and, furthermore, these oocytes do not contain the mitochondrial cloud that localizes Xdazl and other germ plasm components in Xenopus. Maternal Axdazl RNA is inherited in the animal cap and equatorial region of early embryos. At gastrula, neurula, and tailbud stages, Axdazl RNA is widely distributed. Axdazl first shows cell-specific expression in primordial germ cells (PGCs) approaching the gonad at stage 40, when nuage (germ plasm) appears in PGCs. These results suggest that, in axolotls, germ plasm components are insufficient to specify germ cells.

Barriers to providing diabetes care in community health centers.

OBJECTIVE: We aimed to identify barriers to improving care for individuals with diabetes in community health centers. These findings are important because many such patients, as in most other practice settings, receive care that does not meet evidence-based standards. RESEARCH DESIGN AND METHODS: In 42 Midwestern health centers, we surveyed 389 health providers and administrators about the barriers they faced delivering diabetes care. We report on home blood glucose monitoring, HbA1c tests, dilated eye examinations, foot examinations, diet, and exercise, all of which are a subset of the larger clinical practice recommendations of the American Diabetes Association (ADA). RESULTS: Among the 279 (72%) respondents, providers perceived that patients were significantly less likely than providers to believe that key processes of care were important (overall mean on 30-point scale: providers 26.8, patients 18.2, P = 0.0001). Providers were more confident in their ability to instruct patients on diet and exercise than on their ability to help them make changes in these areas. Ratings of the importance of access to care and finances as barriers varied widely; however, >25% of the providers and administrators agreed that significant barriers included affordability of home blood glucose monitoring, HbA1c testing, dilated eye examination, and special diets; nonproximity of ophthalmologist; forgetting to order eye examinations and to examine patients' feet; time required to teach home blood glucose monitoring; and language or cultural barriers. CONCLUSIONS: Providers in health centers indicate a need to enhance behavioral change in diabetic patients. In addition, better health care delivery systems and reforms that improve the affordability, accessibility, and efficiency of care are also likely to help health centers meet ADA standards of care.

Expression of the cardiac actin gene in axolotl embryos.

Axolotis are an important model system for studying heart development. Patterning of the somitic mesoderm occurs in axolotis in a manner that is much more similar to the pattern observed in higher vertebrates than in Xenopus. For these reasons we cloned the axolotl cardiac actin gene, since this gene is expressed during the development of both somitic and cardiac muscle in other vertebrates. In this paper we characterize its expression. Expression of cardiac actin RNA is switched on during gastrula stages and appears in the somitic mesoderm when it is formed; expression is later activated in the embryonic heart. In adults the gene is expressed only in the heart. The results demonstrate that the clone encoding cardiac actin provides a useful marker for studying development of both skeletal and cardiac muscle development in axolotls.

Changes in regional myocardial function after coronary artery bypass graft surgery are predicted by intraoperative low-dose dobutamine echocardiography.

BACKGROUND: Left ventricular dysfunction is often reversed after coronary artery bypass graft (CABG) surgery; however, this change is not easily predicted. The authors hypothesized that functional changes after a low dose of dobutamine (5 microgram. kg-1. min-1) intraoperatively would predict functional changes when complete revascularization was achieved. METHODS: The authors analyzed 560 segments in 40 patients scheduled for elective CABG surgery for regional wall motion (1-5 scoring system) at four stages: baseline (after induction and intubation), with administration of low-dose dobutamine before cardiopulmonary bypass, after separation from cardiopulmonary bypass (early), and after administration of protamine (late). Two independent observers scored the myocardial regions according to a 16-segment model in multiple imaging planes. For each segment, the response to dobutamine was dichotomized as improved or not improved from baseline and analyzed with logistic regression. The influence of covariates (ejection fraction, myocardial infarction, diabetes mellitus, and beta blockers) was also determined with logistic regression models. P < 0.05 was considered significant. RESULTS: Changes in myocardial function after low-dose dobutamine were highly predictive for early (P < 0.0001) and late (P < 0.0001) changes in myocardial function from baseline regional scores. The overall odds ratio for early and late improvement increased by 20.7 and 34.6, respectively, when improvement was observed after low-dose dobutamine was administered. The overall positive predictive value of improved regional wall motion after CABG did not vary with left ventricular ejection fraction, a history of myocardial infarction, or beta blocker use, and it varied little with diabetic status (range, 0.86-0.96) if regional wall motion improved with low-dose dobutamine before CABG. The overall negative predictive value was 0.70; however, the range varied with diabetic status (i.e., lowest in diabetic patients and highest in nondiabetic patients). CONCLUSION: Intraoperative low-dose dobutamine is a reliable method to predict myocardial functional reserve and to determine functional recovery expected after coronary revascularization.

Social environment and year of birth influence type 1 diabetes risk for African-American and Latino children.

OBJECTIVE: Credible epidemiological data, primarily from European-origin populations, indicate that environmental factors play an important role in the incidence of type 1 diabetes. RESEARCH DESIGN AND METHODS: A population-based registry of incident cases of type 1 diabetes among African-American and Latino children in Chicago was used to explore the influence of individual and neighborhood characteristics on diabetes risk. New cases of insulin-treated diabetes in African-American and Latino Chicagoans aged 0-17 years for 1985-1990 (n = 400) were assigned to one of 77 community areas based on street address. Census tables provided denominators, median household income, percentage of adults > or = 25 years old who had completed high school and college, and a crowding variable for each community area individual-level data were birth cohort, sex, and ethnicity. Outcomes in Poisson regression were sex-, ethnic-, and birth cohort-specific incidence rates. RESULTS: Significant univariate associations between diabetes risk and ethnicity, birth cohort, crowding, and the percentage of adults in each community area who had completed high school and college were observed. African-Americans had a relative risk (RR) of 1.42 (95% CI, 1.14-1.76) compared with Latinos. Risk varied significantly by birth cohort in both ethnic groups. For every 10% increase in the proportion of adults who completed college, the RR for diabetes increased by 25% (RR, 1.25 [95% CI, 1.09-1.44]). Social class variables were significant determinants of risk for African Americans, but not for Latinos. CONCLUSIONS: The strong birth cohort and social class associations observed in this study implicate an infectious exposure linked with age.

Sexual harassment and generalized workplace abuse among university employees: prevalence and mental health correlates.

OBJECTIVES: This study hypothesized that interpersonal workplace stressors involving sexual harassment and generalized workplace abuse are highly prevalent and significantly linked with mental health outcomes including symptomatic distress, the use and abuse of alcohol, and other drug use. METHODS: Employees in 4 university occupational groups (faculty, student, clerical, and service workers; n = 2492) were surveyed by means of a mailed self-report instrument. Cross-tabular and ordinary least squares and logistic regression analyses examined the prevalence of harassment and abuse and their association with mental health status. RESULTS: The data show high rates of harassment and abuse. Among faculty, females were subjected to higher rates; among clerical and service workers, males were subjected to higher rates. Male and female clerical and service workers experienced higher levels of particularly severe mistreatment. Generalized abuse was more prevalent than harassment for all groups. Both harassment and abuse were significantly linked to most mental health outcomes for men and women. CONCLUSIONS: Interpersonally abusive workplace dynamics constitute a significant public health problem that merits increased intervention and prevention strategies.

Role of soy protein with normal or reduced isoflavone content in reversing bone loss induced by ovarian hormone deficiency in rats.

Soy protein, a rich source of isoflavones, fed immediately after an ovariectomy prevents bone loss in rats. Reports of the effectiveness of natural and synthetic isoflavones in preventing or treating osteoporosis led us to examine the effect of soy protein in reversing established bone loss. Seventy-two 95-d-old female Sprague-Dawley rats were assigned to 6 groups. The rats were either sham operated (SHAM; 2 groups) or ovariectomized (OVX; 4 groups) and then fed a casein-based, semipurified diet. Thirty-five days after surgery, 1 SHAM and 1 OVX group were killed to examine the occurrence of bone loss. Thereafter, the other SHAM and 1 OVX groups continued to receive the casein-based diet. Whereas the remaining 2 OVX groups received diets in which casein was replaced by soy protein with normal (OVX+SOY) or reduced (OVX+SOY-) isoflavone content for 65 days. The OVX control group had significantly lower femoral and fourth lumbar vertebral bone densities than the SHAM group. Femoral density of rats fed SOY or SOY- diets were not significantly different from SHAM or OVX controls. This suggests a slight reversal of cortical bone loss that may be partially due to higher femoral insulin-like growth factor I mRNA transcripts resulting from both the SOY and SOY- diets. The ovariectomy-induced increases in indexes of bone turnover were not ameliorated by either of the soy diets, suggesting that any positive effect of soy was achieved through enhanced bone formation rather than slowed bone resorption. Long-term consumption of soy or its isoflavones may be needed to produce small but continued increments in bone mass.

Bone-sparing effect of soy protein in ovarian hormone-deficient rats is related to its isoflavone content.

Our previous studies showed that a soy-protein diet prevents ovariectomy-induced bone loss. The purpose of this study was to determine whether isoflavones in soy protein are responsible for this bone-protective effect. Forty-eight 95-d-old Sprague-Dawley rats were divided into 4 groups: sham-operated fed a casein-based diet (SHAM), ovariectomized fed a casein-based diet (OVX+CASEIN), ovariectomized fed soy protein with normal isoflavone content (OVX+SOY), and ovariectomized fed soy protein with reduced isoflavone content (OVX+SOY-). The OVX+SOY group had significantly greater femoral bone density (in g/cm3 bone vol) than the OVX+CASEIN group, whereas OVX+SOY- was similar to OVX+CASEIN (mean +/- SD; SHAM, 1.522 +/- 0.041; OVX+CASEIN, 1.449 +/- 0.044; OVX+SOY, 1.497 +/- 0.030; OVX+SOY-, 1.452 +/- 0.030). Ovariectomy resulted in greater bone turnover as indicated by higher serum alkaline phosphatase activity, serum insulin-like growth factor I and insulin-like growth factor binding protein 3 concentrations, and urinary hydroxyproline. These increases were not affected by soy with either normal or reduced isoflavone content. Similarly, histomorphometry revealed a greater bone formation rate with ovariectomy, and this was not altered by the soy diets. The findings of this study suggest that isoflavones in soy protein are responsible for its bone-sparing effects. Further studies to evaluate the mechanism of action of isoflavones on bone are warranted.

Early discharge. Risks, benefits, and who decides.

Over the last several decades, there has been a significant decrease in the length of hospital stays for mothers and their newborns, ranging from the average of 7 to 10 days before World War II to approximately 2 days in recent years. Many women saw the benefit of early discharge as a means to demedicalize the birth process, to be home with their families sooner, and to have their deliveries be a more positive experience. Although the trend toward shorter hospital stays was originally initiated by consumer interest, the recent further shortening of maternity stays has escalated as a result of insurance and managed care plans attempting to contain health care costs. With this trend toward earlier discharge, a litany of problems have been reported, including missed newborn screening, jaundice, feeding problems, missed congenital anomalies, and readmissions. Although cost-efficient use of health care is vital, the ultimate goal should not only be the prevention of unnecessary morbidity and mortality, but the promotion of health and well being for the child and family.

Filling the gap: equity and access to oral health services for minorities and the underserved.

BACKGROUND AND OBJECTIVES: Family physicians and other primary care providers play a pivotal role in preventing oral disease, especially among minority and underserved populations who have limited access to dental services and poorer oral health status. Oral diseases/conditions, such as caries, baby bottle tooth decay, gingivitis, periodontitis, oral pharyngeal malignancies, and orofacial trauma, are prevalent and costly, yet largely preventable. Given their role in promoting and protecting overall health and their historical role in serving minority and underserved families, family physicians occupy a unique position to assure equity, access, and improvement in oral health for all Americans.

Dietary vitamin C, beta-carotene and 30-year risk of stroke: results from the Western Electric Study.

The relations of dietary antioxidants vitamin C and beta-carotene to 30-year risk of stroke incidence and mortality were investigated prospectively in the Chicago Western Electric Study among 1,843 middle-aged men who remained free of cardiovascular disease through their second examination. Stroke mortality was ascertained from death certificates, and nonfatal stroke from records of the Health Care Financing Administration. During 46, 102 person-years of follow-up, 222 strokes occurred; 76 of them were fatal. After adjustment for age, systolic blood pressure, cigarette smoking, body mass index, serum cholesterol, total energy intake, alcohol consumption, and diabetes, relative risks (and 95% confidence intervals) for nonfatal and fatal strokes (n = 222) in highest versus lowest quartiles of dietary beta-carotene and vitamin C intake were 0.84 (0.57-1.24) and 0.71 (0.47-1.05), respectively. Generally similar results were observed for fatal strokes (n = 76). Although there was a modest decrease in risk of stroke with higher intake of beta-carotene and vitamin-C intake, these data do not provide definitive evidence that high intake of antioxidant vitamins decreases risk of stroke.

Dietary beta-carotene, vitamin C, and risk of prostate cancer: results from the Western Electric Study.

Dietary factors are likely candidates for important determinants of prostatic cancer risk. Among the most investigated nutritional factors have been antioxidants. We evaluated dietary beta-carotene and vitamin C in relation to subsequent risk of prostate cancer in a prospective study of 1,899 middle-aged men. We combined prostate cancer cases diagnosed in the first 24 years of follow-up with incident cases identified from the Health Care Financing Administration hospitalization and outpatient files during an additional 6-year follow-up period. We obtained death certificates for all decedents. During the 30-year follow-up, prostate cancer developed in 132 men. There was no indication that consumption of beta-carotene or vitamin C was related to increased or decreased risk of prostate cancer. Relative risks for highest vs lowest quartiles of beta-carotene and vitamin C intake were 1.27 [95% confidence interval (CI) = 0.75-2.14] and 1.03 (95% CI = 0.59-1.60), respectively, after adjustment for age, number of cigarettes smoked per day, dietary cholesterol and saturated fat, alcohol consumption, total energy intake, and occupation. Associations between intake of these nutrients and risk of prostate cancer differed depending on whether the cancer was diagnosed during the first 19 years of follow-up or the next 11 years of follow-up. Overall survival over the 30 years of follow-up was positively associated with intake of beta-carotene and vitamin C.

Developmental defects in Gorlin syndrome related to a putative tumor suppressor gene on chromosome 9.

Gorlin syndrome is an autosomal dominant disorder that predisposes to basal cell carcinomas of the skin, ovarian fibromas, and medulloblastomas. Unlike other hereditary disorders associated with cancer, it features widespread developmental defects. To investigate the possibility that the syndrome is caused by mutation in a tumor suppressor gene, we searched for loss of heterozygosity in 16 sporadic basal cell carcinomas, 2 hereditary basal cell carcinomas, and 1 hereditary ovarian fibroma and performed genetic linkage studies in five Gorlin syndrome kindreds. Eleven sporadic basal cell carcinomas and all 3 hereditary tumors had allelic loss of chromosome 9q31, and all informative kindreds showed tight linkage between the Gorlin syndrome gene and a genetic marker in this region. Loss of heterozygosity at this chromosomal location, particularly in hereditary tumors, implies that the gene is homozygously inactivated and normally functions as a tumor suppressor. In contrast, hemizygous germline mutations lead to multiple congenital anomalies.

Ethnicity, location, age, and fluoridation factors in baby bottle tooth decay and caries prevalence of Head Start children.

Baby bottle tooth decay (BBTD) is a term applied to a specific form of rampant decay associated with inappropriate bottle or breast feeding of infants and young children. Although the prevalence of BBTD has been studied in individual ethnic groups, comparison studies are rare. Head Start children have frequently served as study subjects for assessing the prevalence of BBTD. The purpose of this study was to compare BBTD and caries prevalence among Head Start children who are members of four ethnic groups in five southwestern States. Age, residence, and fluoridation status were also compared for the total sample and ethnic categories. The sampling process was a stratified random site selection; it was used to obtain data on 1,230 children. This number constituted 3 percent of the children enrolled in Head Start in Public Health Service Region VI (Arkansas, Louisiana, New Mexico, Oklahoma, and Texas) where the study was conducted. The criterion for determining the presence of BBTD was based on the number of carious deciduous maxillary incisors observed. The severity of the condition was reported as two of four and three of four of the target teeth affected. Thus, two levels of severity are reported. BBTD was prevalent in approximately 24 percent and 15 percent of the total sample, depending on the severity criterion used. Native American children had a significantly higher (P less than 0.05) prevalence than Hispanic, white, and black subjects. Rural children had significantly higher (P less than 0.05) prevalence of BBTD than nonrural children for all ethnic groups except whites. The prevalence of decayed and filled (df) surfaces of primary dentition was significantly greater for all rural than for non rural groups (P< 0.05).Children attending centers showed no significant differences based on fluoride status for the total sample or other variables. BBTD and caries prevalence increased with age. Studies are needed to identify predisposing factors among the ethnic groups and residence status in order for more effective preventive regimens to be developed, implemented,and evaluated.

Osteonectin content in human osteogenesis imperfecta bone shows a range similar to that of two bovine models of OI.

Samples of human osteogenesis imperfecta (OI) bone were analyzed for osteonectin content by SDS gel electrophoresis and immunodetection on Western blots. The OI bone osteonectin content varied from normal to severely depressed. Previously, we showed that two clinically identical but genetically unrelated bovine models of OI were differentiated biochemically by their bone osteonectin content: one OI model had normal bone osteonectin while the other was severely depressed in this parameter. The data in this pilot study suggest that further investigation of bone osteonectin content may prove useful in the clinical assessment of human OI cases.

Familial Sotos syndrome (cerebral gigantism): craniofacial and psychological characteristics.

Most reported cases of Sotos syndrome are sporadic, but autosomal dominant and recessive inheritance patterns have been suggested. Ascertainment of a two-generation family through a 7-year-old proposita with a learning disability allowed the relatively unbiased study of two affected relatives. Developmental delay was not pronounced in the patient's mother or sister; craniofacial characteristics at variance with the characteristic description included acrocephaly and maxillary prominence. Steepness of the anterior cranial base angle and protrusion of the middle and lower face, shown in all three patients by cephalometric radiographs, deserve further evaluation as diagnostic criteria.