Prevalence of atrial fibrillation in US nursing homes: results from the National Nursing Home Survey, 1985-2004

ObjectivesTo evaluate the prevalence of atrial fibrillation (AFib) in US nursing homes from 1985 to 2004 and to project the prevalence of AFib to 2030.DesignThis study is an analysis of cross-sectional data from the US National Nursing Home Survey, years 1985, 1995, 1997, 1999, and 2004.SettingRandomly selected long term care facilities in the United States licensed by the state or certified for Medicaid/Medicare reimbursement.ParticipantsRandomly selected residents within study facilities.MeasurementsNational Nursing Home Survey demographics and current medical conditions data were analyzed. Population estimates were calculated using National Nursing Home Survey sample weights. Absolute observed annual linear growth of the AFib prevalence rate was calculated using linear regression. Predictive margins were estimated using logistic regression models to evaluate effect of changes in resident case-mix over the survey years. Three estimation methods predicted the number residents having AFib in 2030.ResultsThe sample sizes of surveyed resident groups were as follows: n = 5238 (1985); n = 8056 (1995); n = 8138 (1997); n = 8215 (1999); and n = 13,507 (2004). Prevalence rates of AFib by year were 2.8% (95% confidence interval [CI]: 2.3–3.4%; 1985), 5.1% (95% CI: 4.6–5.6%; 1995), 5.8% (95% CI: 5.3–6.3%; 1997), 6.9% (95% CI: 6.3–7.4%; 1999), and 10.9% (95% CI: 10.2–11.5%; 2004). Population estimates of nursing home residents with AFib (in thousands) were 42.2 (95% CI: 34.1–50.3; 1985), 78.7 (95% CI: 70.8–86.7; 1995), 93.6 (95% CI: 84.9–102.3; 1997), 111.8 (95% CI: 102.1–121.5; 1999), and 162.1 (95% CI: 152.4–171.7; 2004). Absolute annual linear growth in the prevalence rate of AFib was +0.38% observed (P = .022), +0.39% using unadjusted predictive margins (P = .007), and +0.37% using adjusted predictive margins (P = .007). Projected estimates showed that 272,000 (95% CI: 197,000–347,000), 300,000, or 325,000 residents would have AFib in the year 2030.ConclusionThe prevalence of AFib in US nursing home residents increased from 1985 to 2004 and is projected to grow substantially over the next 20 years, potentially resulting in an increased nursing home staff burden owing to increased stroke risk evaluations.     

Determining human immunodeficiency virus coreceptor use in a clinical setting: degree of correlation between two phenotypic assays and a bioinformatic model

Two recombinant phenotypic assays for human immunodeficiency virus (HIV) coreceptor usage and an HIV envelope genotypic predictor were employed on a set of clinically derived HIV type 1 (HIV-1) samples in order to evaluate the concordance between measures. Previously genotyped HIV-1 samples derived from antiretroviral-na?ve individuals were tested for coreceptor usage using two independent phenotyping methods. Phenotypes were determined by validated recombinant assays that incorporate either an approximately 2,500-bp ("Trofile" assay) or an approximately 900-bp (TRT assay) fragment of the HIV envelope gp120. Population-based HIV envelope V3 loop sequences ( approximately 105 bp) were derived by automated sequence analysis. Genotypic coreceptor predictions were performed using a support vector machine model trained on a separate genotype-Trofile phenotype data set. HIV coreceptor usage was obtained from both phenotypic assays for 74 samples, with an overall 85.1% concordance. There was no evidence of a difference in sensitivity between the two phenotypic assays. A bioinformatic algorithm based on a support vector machine using HIV V3 genotype data was able to achieve 86.5% and 79.7% concordance with the Trofile and TRT assays, respectively, approaching the degree of agreement between the two phenotype assays. In most cases, the phenotype assays and the bioinformatic approach gave similar results. However, in cases where there were differences in the tropism results, it was not clear which of the assays was "correct." X4 (CXCR4-using) minority species in clinically derived samples likely complicate the interpretation of both phenotypic and genotypic assessments of HIV tropism.     

Growth hormone resistance in uremia

Growth retardation is a major complication in children with uremia. Protein restriction, calorie deficit, metabolic acidosis, renal osteodystrophy, and endocrinologic disturbances contribute to the growth failure. The effect of these factors on growth retardation can be attenuated in part by therapy with vitamin D metabolites, adequate nutrition, alkalization, and dialysis. Linear growth in children with uremia is markedly retarded despite normal or increased levels of circulating serum growth hormone. An increased growth hormone level in children with uremia is due to normal growth hormone secretion from the pituitary gland and impaired growth hormone clearance in the kidney. However, the elevated growth hormone level does not lead to a commensurate rise in serum insulin-like growth factor I (IGF-I); the serum IGF-I level is decreased or normal in relation to the degree of renal failure. This discrepancy suggests growth hormone resistance in the liver in uremia. Recent molecular techniques open a new era in studying the gene expression for growth hormone or IGF-I. There is no doubt today that growth hormone treatment has the beneficial effect of growth promotion in children with uremia, which also suggests endogenous growth hormone resistance in target organs or target cells in uremia.     

Pulmonary sequelae in long-term survivors of bronchopulmonary dysplasia

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a common problem in premature babies. Long-term sequelae are the main concerns. METHODS: A retrospective review of all BPD children born in Queen Mary Hospital, a teaching hospital of the University of Hong Kong, from January 1987 to December 1995 was conducted. Children with cerebral palsy, immunodeficiency, congenital heart disorders, renal or liver failure were excluded from analysis. Chest radiography (CXR), electrocardiogram (ECG) and pulse oximetry were routinely performed. RESULTS: Fifty-five children completed the study. The female to male ratio was 1:1.1. The mean gestational age was 28 weeks. Twenty-five children were born with a birthweight of less than 1001 g. Mean age at assessment was 5.4 years. Twenty-four children (44%) demonstrated signs or symptoms of current asthma. Only seven children managed to perform the spirometry satisfactorily. One child had low forced vital capacity and one had hyperresponsive airway. The only risk factor found to be associated with current asthma was the birth month, with those children born early in the year at higher risk of developing current asthma. Seventeen of 48 children (35%) had a bodyweight below the third percentile at the corrected age of 1 year. Eleven of these seventeen children (65%) demonstrated catch-up growth at assessment. Abnormal CXR was found in 25 of 40 children (63%). All had normal pulse oximetry and ECG. CONCLUSIONS: Bronchopulmonary dysplasia children had a significantly higher risk than the general population of developing current asthma (odds ratio 4.7; 95% confidence interval 3.4-6.5; P<0.0001). The importance of birth month suggests that early life experience is important in the pathogenesis of asthma, even in BPD children. The long-term growth of BPD children was much better than previously reported.     

Application of the PRECEDE model to understanding mental health promoting behaviors in Hong Kong.

The burdens related to mental illness have been increasingly recognized in many countries. Nevertheless, research in positive mental health behaviors remains scarce. This study utilizes the Predisposing, Reinforcing, and Enabling Causes in Education Diagnosis and Evaluation (PRECEDE) model to identify factors associated with mental health promoting behaviors and to examine the effects of these behaviors on mental well-being and quality of life among 941 adults in Hong Kong. Structural equation modeling shows that sense of coherence (predisposing factor), social support (reinforcing factor), and daily hassles (enabling factor) are significantly related to mental health promoting behaviors, which are associated with mental well-being and quality of life. Results of bootstrap analyses confirm the mediating role of mental health promoting behaviors on well-being and quality of life. The study supports the application of the PRECEDE model in understanding mental health promoting behaviors and demonstrates its relationships with well-being and quality of life.     

Stellenwert der Radiokephalometrie in der Diagnostik bei OSAS im Erwachsenenalter

Zusammenfassung Untersuchungen zum Zusammenhang zwischen kephalometrischen und polysomnographischen Befunden wurden bisher von mehreren Autoren überwiegend mit linearen statistischen Methoden durchgeführt. Die eigene Arbeitsgruppe interessierte, ob durch den Einsatz mehrdimensionaler statistischer Verfahren der Informationsgehalt der Radiokephalometrie stärker ausgeschöpft werden kann. 77 Patienten mit OSAS (Alter 25 69 Jahre, RDI 3,6 ­ 90,1/h) wurden polysomnographisch und kephalometrisch untersucht. Die Vermessung der knöchernen Parameter erfolgte mit dem Computerprogramm WinCeph und die der Pharynxweichteile in Anlehnung an Hochban et al. (Dtsch Zahnärztl Z 49: 777 782, 1994). Mittels logistischer Regressionen wurde geprüft, ob polysomnographische RDI-Werte > 20 aus dem Röntgenbild vorhergesagt werden können. Die Kopplung der 10 knöchernen Parameter ergab bezüglich der Erkennung erhöhter RDI-Werte eine Sensitivität von 93 % bei einer Spezifität von 44 %. Vier Parameter fielen durch besonders hohe relative Risiken auf. Die alleinige Verwendung der Weichteilparameter zeigte eine Sensitivität von 98 % bei einer Spezifität von 13 %. Die gleichzeitige Betrachtung von Weichteil- und knöchernen Parametern erbrachte eine Sensitivität von 96 % bei einer Spezifität von 40 % in der Erkennung erhöhter RDI-Werte. Die Radiokephalometrie gehört nicht zur Basisdiagnostik des OSAS, sie kann aber bei kieferchirurgischen Operationsentscheidungen einen Beitrag leisten.     

Effects of Formulation and Food on the Absorption of Hydrochlorothiazide and Triamterene or Amiloride from Combination Diuretic Products

The absorption of three combination formulations of hydrochlorothiazide and either triamterene or amiloride was studied over a 5-year period in seven separate investigations under varying conditions of food and fasting. The most widely prescribed combination, containing 25 mg of hydrochlorothiazide and 50 mg of triamterene, demonstrated impaired absorption in the fasting state that was partially corrected by the addition of a breakfast high in fat. The increase in the fat content of the food appeared to correlate directly with the amount of both drugs absorbed from this formulation. The second formulation studied, a new combination formulation of 50 mg of hydrochlorothiazide and 75 mg of triamterene, demonstrated acceptable absorption in the fasting state that was not altered by the concurrent administration of a high-fat breakfast. The absorption of the third formulation, a combination of 50 mg hydrochlorothiazide and 5 mg amiloride, was acceptable in the fasting state and demonstrated a slight reduction in the absorption of the amiloride component when administered concurrently with a high-fat meal. The clinical and biopharmaceutic implications of these observations are discussed.     

Enhancement of T helper type 1 immune responses against hepatitis B virus core antigen by PLGA nanoparticle vaccine delivery.

Currently, there is a need for therapeutic vaccines that are effective in inducing robust T helper type 1 (Th1) immune responses capable of mediating viral clearance in chronic hepatitis B infection. Hepatitis B therapeutic vaccines were designed and formulated by loading the hepatitis B core antigen (HBcAg) into poly(D,L-lactic-acid-co-glycolic acid) (PLGA) nanoparticles with or without monophospholipid A (MPLA), a Th1-favoring immunomodulator. These particles were around 300 nm in diameter, spherical in shape and had approximately 50% HBcAg encapsulation efficiency. A single immunization with a vaccine formulation containing (MPLA+HBcAg) coformulated in PLGA nanoparticles induced a stronger Th1 cellular immune response with a predominant interferon-gamma (IFN-gamma) profile than those induced by HBcAg alone, free (HBcAg+MPLA) simple mixture or HBcAg-loaded nanoparticles in a murine model. More importantly, the level of HBcAg-specific IFN-gamma production could be increased further significantly by a booster immunization with the (HBcAg+MPLA)-loaded nanoparticles. In summary, these results demonstrated that codelivery of HBcAg and MPLA in PLGA nanoparticles promoted HBcAg-specific Th1 immune responses with IFN-gamma production. These findings suggest that appropriate design of the vaccine formulation and careful planning of the immunization schedule are important in the successful development of effective HBV therapeutic vaccines.