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PubMed1999

Predictors of skeletal muscle mass in elderly men and women.

BACKGROUND: Elderly men and women lose muscle mass and strength with increasing age. Decreased physical activity, hormones, malnutrition and chronic disease have been identified as factors contributing to this loss. There are few data, however, for their multivariate associations with muscle mass and strength. This study analyzes these associations in a cross-sectional sample of elderly people from the New Mexico Aging Process Study. METHODS: Data collected in 1994 for 121 male and 180 female volunteers aged 65-97 years of age enrolled in The New Mexico Aging Process Study were analyzed. Body composition was measured using dual energy X-ray absorptiometry; dietary intake from 3 day food records; usual physical activity by questionnaire; health status from annual physical examinations; and serum testosterone, estrone, sex-hormone binding globulin (SHBG), and insulin-like growth factor (IGF1) from radioimmunoassays of fasting blood samples. Statistical analyses included partial correlation and stepwise multiple regression. RESULTS: The muscle mass and strength (adjusted for knee height) decreased with increasing age in both sexes. The muscle mass was significantly associated with serum free-testosterone, physical activity, cardiovascular disease, and IGF1 in the men. In the women, the muscle mass was significantly associated with total fat mass and physical activity. Age was not associated significantly with muscle mass after controlling for these variables. Grip strength was associated with age independent of muscle mass in both sexes. Estrogen (endogenous and exogenous) was not associated with muscle mass or strength in women. CONCLUSIONS: Age-related loss of muscle mass and strength occurs in relatively healthy, well-nourished elderly men and women and has a multifactorial basis. Sex hormone status is an important factor in men but not in women. Physical activity is an important predictor of muscle mass in both sexes.

Aged↗

PubMed2002

Interest in and obstacles to pursuing work among unemployed dually diagnosed individuals.

Employment status is commonly used as a sign of stability in recovery and an outcome variable for substance abuse treatment and research. However, there has been little attention in the literature on the topic of work for the dually diagnosed (i.e., persons diagnosed with both substance use and mental health disorders). Data collected in 1999 are presented on expressed interest in and perceived barriers to pursuing work and on the utilization of vocational rehabilitation (voc-rehab) services among unemployed members of a dual recovery self-help fellowship (N= 130). While members generally expressed high interest in working, they also cited multiple obstacles to attaining and maintaining employment. A path model was specified and tested. Significant contributors to interest in working were substance use status and physical health rating. Consistent with our hypotheses, mental health symptoms and greater perceived obstacles (e.g., stigma, fear of failure, and insufficient skills) were significant contributors to perceived difficulty in pursuing work, whereas substance use, physical health, and recency of employment were not. Finally, those who perceived less difficulty in pursuing work were more likely to utilize voc-rehab services, and men were more likely than women to use these facilities; interest in work was not significantly associated with utilizing voc-rehab services. The roles of mental health disorders and substance use in relation to pursuit of employment are discussed, as well as that of perceived obstacles such as stigma. The paper addresses the setting of realistic vocational goals and possible strategies to mitigate barriers to increased employment of dually diagnosed individuals.

Adult↗

PubMed1999

Peripheral blood mononuclear cell markers in antiretroviral therapy-naive HIV-infected and high risk seronegative adolescents. Adolescent Medicine HIV/AIDS Research Network.

OBJECTIVE: To examine potential hematologic and immunologic markers for healthy adolescents and for adolescents infected with HIV. DESIGN: The REACH Project (Reaching for Excellence in Adolescent Care and Health) of the Adolescent Medicine HIV/AIDS Research Network (AMHARN) recruits HIV-infected and high-risk HIV-uninfected adolescents, aged at least 13 but less than 19 years. The study evaluates biomedical and behavioral features of HIV infection as observed while under medical care for HIV infection and adolescent health. METHODS: Blood samples were collected from HIV-infected and HIV-uninfected subjects at 16 clinical sites. Cell phenotypes were determined using standard single, dual or three-color flow cytometry. RESULTS: This report includes data at enrollment for 94 HIV-positive adolescents who had never received antiretroviral therapy (ART) (mean age, 17.4 +/- 1.0 years for males and 16.5 +/- 1.3 years for females) and 149 HIV-negative adolescents (mean age, 16.7 +/- 1.2 years for males and 16.6 +/- 1.2 years for females); this is the antiretroviral therapy-naive subset drawn from 294 HIV-positive and 149 HIV-negative adolescents enrolled in the REACH Cohort. The total leukocyte count was significantly reduced in the HIV-positive females in comparison with the HIV-negative females (P < 0.001). There was a reduction in natural killer cells (P < 0.05) in HIV-positive females (mean, 140.6 +/- 104.2 x 10(6) cells/l) in comparison with HIV-negative females (184.3 +/- 142.5 x 10(6) cells/l), whereas no differences were found between the two groups of males. The reduction in the total CD4 cell count in HIV-positive males and females in comparison with the HIV-negative subjects was the consequence of a decrease in both the naive CD4 and memory CD4 components. There was a striking increase in the mean number of CD8 memory cells in HIV-positive compared with HIV-negative adolescents, and a corresponding increase in the percentage of these cells. In contrast, naive CD8 cells were present in increased numbers but their percentage was decreased. CONCLUSIONS: These studies of adolescents provide normative data for high-risk healthy adolescents as well as baseline immunologic data for a cohort of ART-naive HIV-positive adolescents. This comparison suggests that this untreated, recently infected group had relatively intact immunologic parameters.

Adolescent↗

PubMed2005

Tracking of activity and sedentary behaviors in childhood: the Iowa Bone Development Study.

BACKGROUND: Physical activity tracking studies can determine when children settle into activity patterns and their risk for maintaining sedentary behaviors. This study examined the tracking of activity and sedentary behavior in relation to adiposity during middle childhood. METHODS: Activity intensities and patterns were examined during a 3-year interval in a population-based study of children using accelerometry and survey methods. Data were collected and analyzed from 1998 to 2004. Participants (n = 379) were, on average, 5.6 (standard deviation [SD] +/- 0.5) years at baseline and 8.6 (SD +/- 0.5) years at follow-up. Adiposity was measured with whole-body, dual-energy x-ray absorptiometry. Correlation coefficients and odds ratios were used to assess tracking. The association of activity with adiposity was tested using the Wilcoxon rank-sum test. RESULTS: Over the 3-year interval, Spearman rank-order correlation coefficients between baseline and follow-up activity measures were low to moderate (r = 0.18 to 0.39). Sedentary behavior was more predictable than overall activity, and tended to be more stable (r = 0.37 to 0.52), with the exception of video playing in boys (r = 0.18). Children maintaining a high degree of vigorous activity and low levels of TV viewing were less likely than peers to be in the upper quartile for adiposity at follow-up, and were less likely to gain adiposity during the study period. CONCLUSIONS: Sedentary behavior, including TV viewing, is moderately stable during middle childhood. Health promotion programs that specifically target maintaining high levels of vigorous activity and low levels of TV viewing may help reduce the increasing prevalence of childhood obesity.

Absorptiometry, Photon↗

PubMed2002

Breath-hold perfusion and permeability mapping of hepatic malignancies using magnetic resonance imaging and a first-pass leakage profile model.

We have applied a novel pharmacokinetic model of the distribution of contrast media to dynamic contrast-enhanced MRI data from patients with hepatic neoplasms. The model uses data collected during the passage of a bolus of contrast medium and allows breath-hold image acquisition. The aims of the study were to investigate the feasibility of permeability mapping using the first pass technique and breath-hold acquisitions, and to examine the reproducibility of the technique and the effect of the liver's dual vascular supply on the assumptions of the model. Imaging was performed in 14 patients with hepatic neoplasms. Dynamic data clearly demonstrated differences in the timing and shape of the contrast medium concentration-time course curve in the systemic arterial and portal venous systems. Mapping of the arrival time (T(0)) of contrast medium allowed identification of tissue supplied by the hepatic arteries and portal vein. Hepatic tumours all showed typical hepatic arterial enhancement. Repeated measurements of endothelial permeability surface area product (k(fp)) and relative blood volume (rBV), performed in five patients, showed excellent reproducibility with variance ratios (V(r)) of 0.134 and 0.113, respectively. Measurement of enhancing tumour volume was also highly reproducible (V(r) = 0.096) and this was further improved by the use of T(0) maps to identify pixels supplied by the hepatic artery (V(r) = 0.026). Estimates of k(fp) and rBV in normal hepatic tissue supplied by the portal vein were highly inaccurate and these pixels were identified by use of the T(0) parameter and excluded from the analysis. In conclusion, dynamic MRI contrast enhancement combined with a pharmacokinetic model of the distribution of contrast media in the first pass allows us to produce highly reproducible parametric maps of k(fp) and rBV from hepatic tumours that are supplied by the hepatic arterial system using breath-hold acquisitions.

Adenocarcinoma↗

PubMed2004

Body composition in the SOS (Swedish Obese Subjects) reference study.

OBJECTIVE: The primary objective was to establish population-based, sex- and age-specific reference data with respect to body composition variables. Secondary objectives were to relate body mass index (BMI) to anthropometric measurements reflecting central adiposity and to body fat (BF). Another objective was to examine if secular changes in adipose tissue distribution occurred during the sampling period, 1994-1999. DESIGN: Sex- and age-specific data on anthropometric measurements and body composition were cross-sectionally collected in the reference study of Swedish Obese Subjects. SUBJECTS: In total, 1135 randomly selected subjects (524 men and 611 women), aged 37-61 y, BMI 17.6-45.4 kg/m(2). MEASUREMENTS: Measures of body fatness and fat distribution (by dual energy X-ray absorptiometry and anthropometry) were collected. RESULTS: At BMI 25 kg/m(2), relative (absolute) BF mass was 24% (19 kg) in men vs 36% (25 kg) in women, waist circumference was 90 vs 85 cm, and sagittal trunk diameter was 21 vs 19 cm. BF and measures of centralized adipose tissue distribution increased with age in both sexes (P<0.01). In women, waist circumference and sagittal diameter increased (P<0.01) over the sampling period while BMI did not. CONCLUSIONS: Sex- and age-specific reference data on body composition are reported from a randomly selected sample of Swedish men and women. At given BMIs, women had more BF but smaller waist circumference than men. Secular increases in indices of central obesity were found in women but not in men.

Absorptiometry, Photon↗

PubMed2007

Two methods for the determination of enantiomeric excess and concentration of a chiral sample with a single spectroscopic measurement.

The previously established enantioselective indicator-displacement assays (eIDAs) for the determination of concentration and enantiomeric excess (ee) require two spectroscopic measurements for each chiral sample. To further simplify the operation of eIDAs, we now introduce two innovative analytical methods, both of which utilize a dual-chamber quartz cuvette, which reduces the number of spectroscopic measurements from two to one. An attractive feature of this cuvette is that the concentration- and ee-dependent absorption data can be collected at the isosbestic points or transparent regions of the spectra recorded in each individual chamber, thereby reflecting optical changes that occur in the other chamber. Therefore, two independent equations, which are needed to solve the values of the two independent variables-concentration and ee-can be established with only a single spectroscopic measurement. The first method takes advantage of this feature in conjunction with a judicious choice of indicator/host combinations to generate concentration- and ee-dependent calibration curves. Our second method removes the requirement to measure equilibrium constants and molar absorptivities altogether through the use of artificial neural networks (ANNs). The most frequently used three-layer feed-forward network is generated, which relates the absorption data to concentration and ee of the samples by training with a back propagation procedure. Here, the data collection is not limited to the isosbestic points or transparent regions. Both approaches enabled accurate and rapid determination of concentration and ee of chiral samples. The technology removes the relative difficulty, which is the need for two separate measurements for concentration and ee respectively, of analyzing chiral samples compared to achiral samples. When implemented in a high-throughput format, this technology should greatly facilitate the discovery of asymmetric catalysts in the same way as conventional high-throughput screening assays.

Molecular Structure↗

PubMed1991

[MRI of white matter pathways].

CT scan shows some relatively large white matter pathways such as corpus callosum or internal capsule, while MRI provides more sophisticated display of cerebral white matter pathways, based partly on difference in the water content, which improves contrast resolution of structures that cannot be appreciated on CT scanning. The white matter shows slightly high signal intensity in T1WI as compared with the peripheral gray matter. In contrast, it is relatively low signal intensity in long TR sequence. The signal intensity is correlated with myelination, density of myelin fibers and possibly iron deposition. In this study, we collected data on 30 patient, aged from 3 to 60 years average 38 years of normal MRI study of the brain. We routinely obtained T1 Weighted image (T1WI, TR/TE 500-600/20 msec), dual echoes image of proton density image (PDI, TR/TE 2000-3000/20 msec), T2 weighted image (T2WI, TR/TE 2000-3000/80-120 msec), in axial and coronal sections. In some cases sagittal section was also imaged. We identified the white matter pathways based on the data from the axial and coronal sections of 2 autopsy specimens. We also consulted several textbooks and literature reviews of gross and MRI anatomy. The following white matter pathways could be clearly observed on MRI: 1. Projection fibers: corona radiata and internal capsule; 2. Commissural fibers: corpus callosum and anterior commissure; 3. Associated fibers: superior occipito-frontal fasciculus, superior longitudinal fasciculus, ucinate fasciculus, cingulum bundle, optic radiation fornix and mammillothalamic tract.

Adolescent↗

PubMed2005

Effect of closed unit policy and appointing an intensivist in a developing country.

OBJECTIVE: We hypothesized that a dual strategy--instituting a closed intensive care unit (ICU) policy and simultaneously appointing an intensivist--would improve patient outcome in a university hospital of a developing country and that the benefit would increase over time. DESIGN: Data were prospectively collected over 5 months before the policy change (open policy) and over an initial 6 mos (early closed policy) and subsequent 12 mos (late closed policy) after the policy change. SETTING: The study was conducted at a medical ICU of a university hospital in Turkey. PATIENTS: Two hundred patients were recruited during open policy, 149 during early closed policy, and 210 during late closed policy. MEASUREMENTS AND RESULTS: Instituting a closed policy and simultaneously appointing a critical care specialist was associated with the admission of sicker patients and more frequent use of invasive procedures. Compared with open policy, patients were approximately 4.5 times more likely to survive their hospital stay during early closed policy (p < .001) and approximately five times more likely during late closed policy (p < .0001). Among patients receiving mechanical ventilation, hospital mortality was lower during the early (57%) and late closed periods (59%) than during open period (91%; p < .01). In multivariate analysis, open policy, mechanical ventilation, central venous catheterization, sepsis, and higher Acute Physiology and Chronic Health Evaluation II score each independently predicted mortality. The change in policy resulted in the admission of progressively sicker patients over time and increased the use of mechanical ventilation and central venous catheters. CONCLUSION: A dual strategy of closed policy and simultaneously appointing an intensivist fostered admission of sicker patients and improved the survival of patients requiring admission to an ICU of a developing country.

APACHE↗

PubMed1989

Dual regulatory mechanisms of proton transport in rat papillary collecting duct cells in culture.

The regulation of proton transport and cytosolic pH was studied in rat papillary collecting duct (PCD) cells in culture using a pH-sensitive fluorescence probe, 2,7-bis-carboxyethyl-5,6-carboxyfluorescein (BCECF). Data were obtained from confluent monolayers grown on glass coverslips and dipped in a HCO3- -free medium, pH 7.40. The resting intracellular pH (pHi) was 7.16 +/- 0.03 (n = 20). When PCD cells had been acidified by pretreatment with NH4Cl, pHi immediately recovered toward the resting value. Two mechanisms participated in this recovery: a Na+-dependent mechanism which could be inhibited by amiloride (indicative of Na+-H+ exchanger) and a Na+-independent process (a proton ATPase). The pHi recovery from acid loading was inhibited by amiloride to about 55% of the control recovery (half-maximal effect at 100 microM). The rate of pHi recovery after the readdition of Na+ to a sodium-free medium exhibited saturation kinetics (half maximal rate at 28 mM). Dicyclohexylcarbodiimide (DCCD), an inhibitor of a plasma membrane proton ATPase, and the depletion of cellular ATP induced by 2 mM potassium cyanide (KCN) also partially inhibited the rate of pHi recovery after cell acidification with a NH4Cl load. When PCD cells were treated with 1 mM DCCD, amiloride almost completely inhibited pHi recovery. Amiloride and the removal of external Na+ had induced a gradual fall in pHi to a new resting value and rapidly recovered when Na+ was added. We conclude that PCD cells grown in culture have at least two proton transport mechanisms: a Na+-H+ exchanger and a plasma membrane proton ATPase. The kinetics of these processes can be reliably assessed by the pH-sensitive fluorescent probe, BCECF. Both the Na+-H+ exchanger and the plasma membrane proton ATPase may contribute to urinary acidification.

Adenosine Triphosphatases↗

PubMed1998

Meta-analysis about efficacy of anti-resorptive drugs in post-menopausal osteoporosis.

OBJECTIVE: The purpose of this study was to compare the effect of three groups of anti-resorptive drugs in post-menopausal osteoporosis. DATA SOURCES: We collected data covering the period between 1983 and 1995, by first using MEDLINE. References retrieved were scanned further to identify additional papers. STUDY SELECTION: Only randomized studies evaluating bone mass by means of dual-photon or dual energy densitometry over a period of 1 year were accepted. DATA EXTRACTION: Studies were arranged into three drug groups. We used densitometry results after 1 year in all treatment or control groups. Factors which might interfere with the results were recorded for subsequent separate analysis. DATA SYNTHESIS: The MEDLINE search identified almost 25,000 studies. On reading the abstracts, 275 trials appeared to be controlled trials and original copies were retrieved for detailed analysis. A total of 31 articles which satisfied the inclusion criteria were identified. The first meta-analysis included studies which compared oestrogens and placebo, and the global effect-size was 0.54 (95% CI 0.34, 0.73). The second meta-analysis compared calcitonins with placebo and produced an effect-size of 0.41 (95% CI 0.21, 0.61) The third analysis compared bisphosphonates and placebo and showed an effect-size of 0.87 (95% CI 0.68, 1.07). Only oestrogen dose affected the results found. CONCLUSIONS: Bisphosphonates had the greatest effect on bone mass in post-menopausal osteoporosis.

Bone Resorption↗

PubMed2006

Haemoglobin A1c is not a surrogate for glucose and insulin measures for investigating the early life and childhood determinants of insulin resistance and Type 2 diabetes in healthy children. An analysis from the Avon Longitudinal Study of Parents and Children (ALSPAC).

AIMS: Research into early life and childhood determinants of insulin resistance and Type 2 diabetes are complicated by requirements for fasting blood samples and glucose tolerance tests. We investigated haemoglobin A(1c) (HbA(1c)), a marker of glycaemia measured in non-fasting blood, as an alternative. METHODS: HbA(1c) was measured in 1645 children aged 9-11 years without diabetes from the Avon Longitudinal Study of Parents and Children. Thirty-nine children had two HbA(1c) measurements. Data on parental, child and potential confounding factors were collected prospectively from questionnaires, medical records and direct examination. Data from a shortened 30-min oral glucose tolerance test were available for 431 children at age 8 years. Body composition was measured by dual-energy X-ray absorptiometry. RESULTS: Mean (sd) HbA(1c) was 4.91(0.29)%. HbA(1c) increased with age and was higher in boys compared with girls, non-white compared with white children, and in children with anaemia. Mean difference between repeated HbA(1c) measurements was 0.01%. HbA(1c) was weakly positively associated with fasting glucose (beta = 0.066%/mmol/l, P = 0.05), but was not associated with 30-min glucose, fasting or 30-min insulin, or homeostasis model assessment-insulin resistance. HbA(1c) was weakly inversely associated with weight sd score (beta =-0.02%/unit, P = 0.004), body mass index sd score (beta = -0.02%/unit, P = 0.002), and total body fat (beta = -0.003%/kg, P = 0.06) and lean mass (beta = -0.011%/kg, P = 0.01), but was not associated with birthweight or breastfeeding. CONCLUSIONS: HbA(1c) is not a good marker of fasting or post-load glucose and insulin measures in healthy children, and is not a viable alternative to these measures for investigating the determinants of insulin resistance and Type 2 diabetes in children.

Biomarkers↗

PubMed2003

The effect of dual infection with HIV and malaria on pregnancy outcome in western Kenya.

OBJECTIVE: To determine the effect of dual infection with HIV and malaria on birth outcomes and maternal anaemia among women delivering at a large public hospital in Kisumu, western Kenya. SUBJECTS AND METHODS: Data on obstetric and neonatal characteristics, maternal and placental parasitaemia, and postpartum haemoglobin levels were collected from women enrolled in a cohort study of the interaction between malaria and HIV during pregnancy. RESULTS: Between 1996 and 1999, data were available from 2466 singleton deliveries. The maternal HIV seroprevalence was 24.3%, and at delivery 22.0% of the women had evidence of malaria. Low birthweight, preterm delivery (PTD), intrauterine growth retardation (IUGR) and maternal anaemia (haemoglobin < 8 g/dl) occurred in 4.6, 6.7, 9.8 and 13.8% of deliveries, respectively. Maternal HIV, in the absence of malaria, was associated with a 99 g (95% CI 52-145) reduction in mean birthweight among all gravidae. Malaria was associated with both IUGR and PTD, resulting in a reduction in mean birthweight of 145 g (95% CI 82-209) among HIV-seronegative and 206 g (95% CI 115-298) among HIV-seropositive primigravidae, but not among multigravidae. Both HIV and malaria were significant risk factors for postpartum maternal anaemia, and HIV-seropositive women with malaria were twice as likely to have anaemia than HIV-seronegative women with or without malaria. CONCLUSION: Women with dual infection are at particular risk of adverse birth outcomes. In areas with a moderate or high prevalence of HIV and malaria, all pregnant women should be the focus of malaria and anaemia control efforts to improve birth outcomes.

Adult↗

PubMed2025

Impact of Race on Profiles of Platelet Reactivity and Clinical Outcomes in Clopidogrel-Treated Participants.

Black individuals undergoing percutaneous coronary intervention (PCI) experience higher rates of major adverse cardiovascular events (MACE) than non-Black individuals. This study assessed the racial differences in platelet reactivity and clinical outcomes among clopidogrel-treated participants. Two cohorts were analyzed. The pharmacodynamic (PD) cohort involved patients with atherosclerotic cardiovascular disease on maintenance clopidogrel therapy undergoing platelet function testing. The primary outcome was high platelet reactivity (HPR, i.e., P2Y12 reaction unit [PRU] > 208). The PCI cohort included participants undergoing PCI on clopidogrel-based dual antiplatelet therapy. The primary outcome was 1-year MACE, defined as the composite of cardiovascular death, myocardial infarction (MI), ischemic stroke, or stent thrombosis. Data on clinically significant bleeding and CYP2C19 genotyping alleles were collected. The PD and PCI cohorts included 728 (32.1% Black) and 2,770 (20.5% Black) participants, respectively. Black participants had higher PRU levels (184 [IQR 128-234] vs. 144 [IQR 88-195]; P < 0.001) and higher prevalence of HPR (39.3% vs. 20.6%; P < 0.001). Independent predictors of HPR included Black race, hemoglobin levels, and presence of CYP2C19 loss-of-function allele. In the PCI cohort, Black participants had a higher risk of MACE (HR 1.47; 95% CI 1.02-2.11; P = 0.037), primarily driven by MI (HR 1.71; 95% CI 1.09-2.67; P = 0.019), with no significant difference in clinically significant bleeding (HR 1.08; 95% CI 0.65-1.80; P = 0.768). Black participants on clopidogrel exhibit higher platelet reactivity, increased rates of HPR, and an elevated risk of MACE within 1 year after PCI, without significant differences in bleeding compared to non-Black participants.

Aged↗

PubMed2002

EPR adoption and dual record maintenance in the U.S.: assessing variation in medical systems infrastructure.

The growing adoption of evidence-based medicine in the United States is acting to cause fundamental changes in the delivery of healthcare management services. With the increasing incorporation of electronic patient records (EPRs) into the day-to-day practice of medicine, it necessitates greater dependence on adequate functioning of such resources, as they become more frequently used as a clinical complement in the practice of medicine. Assessing the patterns of adoption of EPRs is likewise of increasing importance, with the recent imposition of uniform government data collection and management requirements. The medium of data storage and maintenance within many organizations is a critical factor in the ultimate delivery of service, with a like need for an integrated, designated medium for the management of data becoming paramount. This study examines, on a nationwide basis, variation in reported adoption of EPRs within U.S. healthcare organizations, and the related maintenance of dual electronic/paper record systems.

Database Management Systems↗

PubMed2001

Multisite quantitative ultrasound: precision, age- and menopause-related changes, fracture discrimination, and T-score equivalence with dual-energy X-ray absorptiometry.

This study evaluated the clinical utility of a new multisite ultrasound device capable of measuring speed of sound (SOS) at the phalanx, radius, tibia and metatarsal. The in vitro and in vivo short- and long-term precision were evaluated, reference data were collected for 409 healthy white women (236 premenopausal and 173 postmenopausal), and age and menopause related changes were calculated using linear regression. Fracture discrimination was evaluated using 109 women with vertebral fractures and the age-adjusted odds ratios calculated for each standard deviation decrease in SOS measurement. Correlations between SOS measurements and spine and femur bone mineral density (BMD) were calculated. T-score equivalence with BMD was also investigated together with the prevalence of osteoporosis as defined by the WHO criteria. The in vivo short-term precision standardized in T-score units ranged from 0.14 to 0.33 and long-term standardized precision was 0.35-0.65. Postmenopausal age-related bone loss expressed as the annual change in T-score ranged from 0.040 to 0.089 for SOS and 0.053 to 0.066 for BMD, whilst menopause-related annual loss ranged from 0.036 to 0.094 for SOS and 0.050 to 0.074 for BMD. Correlations between the different SOS sites ranged from r = 0.24 to 0.55, and between SOS and BMD from r = 0.12 to 0.47. The odds ratio (and 95% confidence intervals) for fracture per 1 SD decrease in SOS were 2.0 (1.22 to 3.23) for the phalanx; 1.5 (1.01 to 2.24) for the metatarsal; 1.4 (1.03 to 1.99) for the radius and 1.2 (0.87 to 1.66) for the tibia. Odds ratios for BMD in the same population ranged from 2.6 to 4.8 (1.70 to 8.29). The prevalence of osteoporosis as defined by T = <-2.5 in the age range 60-69 ranged from 7.1% to 20.6% for SOS and 6.4% to 12.1% for BMD. In conclusion, this study demonstrated that multisite ultrasound has adequate precision for investigating skeletal status, is capable of differentiating between pre- and postmenopausal women and women with vertebral fractures, has a T-score equivalence similar to that of dual-energy X-ray absorptiometry (DXA), and appears to be a promising new technique for evaluating skeletal status at clinically relevant sites.

Absorptiometry, Photon↗

PubMed2002

Clinical evaluation of etched porcelain onlays: a 4-year report.

Etched porcelain-bonded-to-enamel restorations (porcelain veneers) have demonstrated a low incidence of debonding, fracture, microleakage, and discoloration. In addition, laboratory and short-term clinical studies have shown satisfactory results with posterior etched porcelain-bonded restorations. This study evaluated the 4-year clinical performance of posterior all-ceramic onlays and overlays bonded with a dual-cure luting resin and a self-cure acetone-based dentinal adhesive. Twenty-one posterior porcelain overlay restorations were fabricated from a high-leucite-content porcelain and bonded to the teeth of 12 adults using a dual-cure luting resin and an acetone-based self-cure N(P-tolyl) glycine-glycdyl methacrylate (NTG-GMA), pyromellitic acid dianhydride and 2-hydroxyethyl methacrylate (PMDM) dentinal adhesive. Restorations were examined for retention, marginal caries, marginal microleakage, sensitivity, discoloration, restorative fracture, and patient satisfaction. Data collected at 4 years revealed 100% retention of the restorations with no marginal discoloration, marginal ditching, caries, or sensitivity. A small gap (Ryge UPHS rating of Bravo) was detected at the facial margin of one restoration but was not sufficient enough to require repair or replacement. Each patient reported a very high level of satisfaction with the restorations. This study demonstrates that porcelain overlays with supragingival margins entirely on enamel that rely primarily or entirely on bonding for their retention can provide excellent esthetics, good function, and perhaps long-term durability if properly designed, fabricated, and bonded. Porcelain overlays fabricated from high-leucite-content porcelain bonded to sound enamel and dentin with a dual-cure luting resin and a fourth generation dentinal adhesive provide satisfactory clinical results and high patient satisfaction.

Acid Etching, Dental↗

PubMed2001

The antiosteoporotic efficacy of intravenous pamidronate in men with prostate carcinoma receiving combined androgen blockade: a double blind, randomized, placebo-controlled crossover study.

BACKGROUND: Prostate carcinoma therapy with combined androgen blockade may result in high bone-turnover with significant bone loss. This study was undertaken to evaluate the antiosteoporotic efficacy of intravenous pamidronate in a double blind, randomized, placebo-controlled, crossover study. METHODS: Twenty-one consecutive men with metastatic prostate carcinoma who were receiving combined androgen blockade with a long-acting gonadotropin-releasing hormone agonist (gosarelin acetate) and an androgen antagonist (flutamide or bicalutamide) were evaluated at baseline and at 6 and 12 months after therapy. They were randomly assigned to receive a single intravenous infusion of 500 mL of normal saline solution diluted with either pamidronate (90 mg) or placebo at baseline and with a crossover at 6 months. Lumbar-spine bone-mineral densities (BMDs) were measured by spinal quantitative computed tomography (QCT), femoral neck BMDs were measured by dual-energy X-ray absorptiometry (DXA), and markers of bone turnover were measured by noninvasive methods. Data on 10 men with localized prostate carcinoma who were treated with radiotherapy alone, over the same period, was collected for comparison studies. RESULTS: The mean age of the men was 75.1 years +/- 1.6 years. One man withdrew from the study because of deteriorating health, and two died from metastatic disease within the first 6 months. Combined androgen blockade normalized serum prostate-specific antigen activities (from an initial mean value of 86.2 ng/mL +/- 10.1 ng/mL) and maintained serum free testosterone concentrations in the hypogonadal range (< 2.2 pmol/L) in all men throughout the study. Treatment with pamidronate resulted in a 7.8% +/- 1.5% increase in mean lumbar spine QCT from 79.4 mg/cm(3) (95% confidence interval [CI], 64-94 mg/cm(3)) to 85.6 mg/cm(3) (95% CI, 70-101 mg/cm(3)) (P = 0.0005) and a 2% +/- 0.9% increase in mean total femoral neck DXA from 0.98 g/cm(2) (95% CI, 0.90 -1.05 g/cm(2)) to 1.0 mg/cm(2) (95% CI, 0.91-1.08 g/cm(2)) (P = 0.02). Conversely, treatment with placebo, resulted in a 5.7% +/- 1.6% decrease in mean lumbar spine QCT and a 2.3% +/- 0.7% decrease in mean total femoral neck DXA (P = 0.0001 and P = 0.0007 for the comparison of percentage change between the pamidronate and placebo treatments). After pamidronate therapy, serum bone Gla-protein concentrations decreased by 16.8% +/- 5.9%, and urinary deoxypyridinoline excretion rates decreased by 18.5% +/- 12.8% (P < 0.01 respectively for the comparison between pamidronate and placebo treatment). CONCLUSIONS: This study demonstrated that a single intravenous infusion of pamidronate (90 mg) significantly reduced the high bone turnover and bone loss (for at least 6 mos) in men with prostate carcinoma who had been rendered hypogonadal with combined androgen blockade therapy.

Aged↗