Biomedical subjects

Hossein N Yarandi

Publications and source records attributed to Hossein N Yarandi.

12 recordsLinked to original sources

PubMed2006

Influence of coagulation factor, vitamin K epoxide reductase complex subunit 1, and cytochrome P450 2C9 gene polymorphisms on warfarin dose requirements.

INTRODUCTION: The primary objective of this study was to determine whether variability in warfarin dose requirements is determined by common polymorphisms in genes whose products are involved in the pharmacodynamics and pharmacokinetics of warfarin, namely, the coagulation factors, vitamin K epoxide reductase complex subunit 1 (VKORC1), and cytochrome P450 (CYP) 2C9. METHODS: Patients (N = 350) receiving stable doses of warfarin at 3 consecutive visits were enrolled, and a deoxyribonucleic acid sample was collected. Samples were genotyped for polymorphisms in the factor II, factor VII, factor X, VKORC1, and CYP2C9 genes. A stepwise linear regression analysis was used to determine the independent effects of genetic and nongenetic factors on mean warfarin dose requirements. RESULTS: Variables associated with lower warfarin dose requirements were VKORC1 3673 AA genotype (P < .0001), VKORC1 3673 GA genotype (P < .0001), 1 variant CYP2C9 allele (P < .0001), 2 variant CYP2C9 alleles (P = .0004), increasing age (P = .0005), concomitant CYP2C9 inhibitors (P = .0005), and goal international normalized ratio (P = .01). Variables associated with higher warfarin dose requirements were weight (P < .0001), current smoker status (P = .0009), mean international normalized ratio (P = .001), concomitant CYP2C9 inducers (P = .006), factor X insertion/deletion genotype (P = .01), factor X insertion/insertion genotype (P = .04), factor VII deletion/deletion genotype (P = .04), and calculated vitamin K intake (P = .05). The linear regression model explained 51.4% of the variability in warfarin dose requirements. CONCLUSION: Polymorphisms in warfarin drug target and metabolizing enzyme genes, in addition to nongenetic factors, were important determinants of warfarin dose requirements.

Adult↗

PubMed2006

Discordant beta-blocker effects on clinic, ambulatory, resting, and exercise hemodynamics in patients with hypertension.

STUDY OBJECTIVES: To determine the correlation between ambulatory and clinic blood pressure in assessing antihypertensive response to beta-blockade, to test whether blood pressure response to metoprolol is associated with the heart rate response, and to determine whether exercise and resting heart rate responses to metoprolol are correlated. DESIGN: Post hoc analysis of a prospective cohort study. SETTING: University-affiliated general clinical research center. PATIENTS: Fifty-one patients aged 35-65 years with uncomplicated hypertension. Intervention. All patients received metoprolol at a dosage titrated to achieve a diastolic blood pressure below 90 mm Hg. MEASUREMENTS AND MAIN RESULTS: Clinic and 24-hour ambulatory blood pressure measurements were obtained and exercise treadmill testing was performed before and after metoprolol treatment. Based on ambulatory blood pressure data, 24 patients (47%) responded (defined as at least a 10% reduction in diastolic blood pressure) to metoprolol compared with 36 patients (71%) based on clinic blood pressure data (p=0.027). Clinic blood pressure was associated with a 67% false-positive rate (responsive blood pressure by clinic data that was actually nonresponsive by ambulatory data). Blood pressure responders and nonresponders exhibited similar reductions in exercise heart rate (24% and 23%, p=0.74). However, responses to metoprolol measured by exercise heart rate versus resting heart rate were not significantly correlated (r=0.24, p=0.105). CONCLUSION: Reliance on clinic blood pressure or resting heart rate for making beta-blocker treatment decisions may yield less than optimal assessment of the antihypertensive response or degree of beta-blockade.

Adrenergic beta-Antagonists↗

PubMed2005

beta-Adrenergic receptor polymorphisms and responses during titration of metoprolol controlled release/extended release in heart failure.

OBJECTIVE: beta-Blockers require careful initiation and titration when used in patients with heart failure. Some patients tolerate beta-blocker therapy initiation without difficulty, whereas in other patients this period presents clinical challenges. We tested the hypothesis that polymorphisms at codons 389 (Arg389Gly) and 49 (Ser49Gly) of the beta(1)-adrenergic receptor would be associated with differences in initial tolerability of beta-blocker therapy in patients with heart failure. We also tested whether polymorphisms in the beta(2)-adrenergic receptor, G-protein alpha s subunit (G(s)alpha), and cytochrome P450 (CYP) 2D6 genes or S-metoprolol plasma concentrations were associated with beta-blocker tolerability. METHODS: Sixty-one beta-blocker-naive patients with systolic heart failure were prospectively enrolled. Patients began taking 12.5 to 25 mg metoprolol controlled release/extended release with titration every 2 weeks (as tolerated) to 200 mg/d or the maximum tolerated dose over a period of 8 to 10 weeks. Decompensation was the composite of death, heart failure hospitalization, increase in other heart failure medications, or need to discontinue metoprolol. End points were assessed during the titration period. RESULTS: The overall rate of decompensation was not different between the codon 49 or 389 genotypes. However, a significantly greater percentage of patients with the Gly389 variant required increases in heart failure medications as compared with Arg389 homozygotes (48% versus 14%, respectively; P = .006). Similarly, patients with the Ser49 homozygous genotype were significantly more likely to require increases in concomitant heart failure therapy as compared with Gly49 carriers (41% versus 11%, respectively; P = .03). Neither CYP2D6 genotypes nor metoprolol pharmacokinetics differed between patients with and those without a decompensation event. There was no association between the beta(2)-adrenergic receptor or G(s)alpha polymorphisms with decompensated heart failure. CONCLUSIONS: Patients with the Gly389 variant and Ser49Ser genotype were significantly more likely to require increases in heart failure medications during beta-blocker titration and thus may require more frequent follow-up during titration.

Cytochrome P-450 CYP2D6↗

PubMed2005

Beta1-adrenergic receptor polymorphisms and left ventricular remodeling changes in response to beta-blocker therapy.

OBJECTIVE: Large variability exists in the improvement in left ventricular (LV) function from beta-blocker treatment. We hypothesized that polymorphisms at codon 389 (Arg389Gly) and 49 (Ser49Gly) in the beta1-adrenergic receptor (AR) gene were associated with LV reverse remodeling changes in response to beta-blocker therapy among heart failure patients. METHODS: We prospectively enrolled 61 beta-blocker naive patients with systolic heart failure. Patients underwent baseline echocardiography followed by metoprolol CR/XL. The dose was doubled on a biweekly basis up to 200 mg/day or attainment of maximum tolerated dose. Echocardiography was repeated after the patient received the target or highest tolerated dose for 3 months. RESULTS: Among patients with the Arg389Arg genotype, ejection fraction (EF) increased from 23+/-5 to 29+/-10 (P=0.008). Gly389 carriers did not demonstrate any significant change in EF (22+/-9 to 23+/-11; P=0.45). There was a significant between-group difference in EF by genotype (P=0.04). The Arg389Arg genotype was also associated with significantly greater reductions in LV end-diastolic and end-systolic diameters compared to Gly389 carriers. Patients with the Gly49 variant also had a significantly greater reduction in LV end-diastolic diameter compared to Ser49 homozygotes. Multiple regression analysis modeling revealed that the codon 389 polymorphism was a significant predictor of an improvement in EF and both codon 49 and 389 polymorphisms were significant predictors of final LV end-diastolic diameter. CONCLUSIONS: Heart failure patients with the Arg389Arg genotype and Gly49 carriers had greater improvements in LV remodeling from beta-blocker treatment.

Adrenergic beta-Antagonists↗

PubMed2004

Influence of gender and race on hemodynamic response to dobutamine during dobutamine stress echocardiography.

This study sought to determine the influence of gender and/or race on the hemodynamic response to dobutamine during dobutamine stress echocardiography. Blood pressure response patterns differed by gender and race, and completion of testing was often limited because of adverse events, namely, hypertension. Gender and racial differences in blood pressure response merit consideration as potential contributors to the suboptimal response in dobutamine stress testing.

Adult↗

PubMed2004

The effect of dyadic intervention on self-efficacy, social support, and depression for men with prostate cancer.

Urinary and sexual dysfunctions are side effects of radical prostatectomy (RP) for prostate cancer (PC) that contribute to depression. Despite the effectiveness of support groups at reducing depression in cancer patients, men typically do not participate in them. The purpose of this pilot study was to test the effects of a dyadic intervention (one-to-one support) on social support (Modified Inventory of Socially Supportive Behaviors), self-efficacy (Stanford Inventory of Cancer Patient Adjustment), and depression (Geriatric Depression Scale). Subjects were randomized to group. Controls (N=15; Mage=59.7) received usual care. Experimentals were paired with long-term survivors (LTS) who had RP and who had treatment side effects in common. Experimentals (N=15; Mage=57.5) met with a LTS 8 times in 8 weeks to discuss concerns associated with survivorship. No significant differences were detected on social support, but after 4 weeks, significant differences were present on depression between controls and experimentals, however these differences were not seen at 8 weeks. After 8 weeks, there were also significant differences on self-efficacy between controls and experimentals. Weekly anecdotal data supported the feasibility and acceptance of the intervention that was a low cost strategy effective at reducing depression and increasing self-efficacy in men treated by RP. Future research directions and clinical application is presented.

Adaptation, Psychological↗

PubMed2004

A knowledge comparison of nursing students in perioperative versus other rotations.

As more patients undergo surgical interventions in ambulatory facilities and patients in acute care settings have shorter lengths of stay, nursing students may have limited interaction with the surgical patient population. This study used a repeated measure, experimental design to compare knowledge of surgical patient care among undergraduate nursing students who experienced a perioperative clinical rotation (ie, experimental groups) with knowledge among students who experienced rotations in other clinical settings (ie, control groups). Results demonstrated a significant change in mean knowledge scores over time and a significant difference in mean scores between the experimental and control groups. Students in the perioperative group scored higher in all four testing periods.

Adult↗

PubMed2004

HIV and older adults: clinical outcomes in the era of HAART.

As the human immunodeficiency virus (HIV) epidemic enters its third decade, nurses are caring for increasing numbers of older adults with HIV who are on complicated medication regimens or highly active antiretroviral therapy (HAART). Although HAART has revolutionized HIV and acquired immunodeficiency syndrome (AIDS) care, little is known about how older adults respond to the new therapies. A review of the medical records of 19 older (> or = 50 years) and 18 younger (< 40 years) adults initiated on their first HAART regimen revealed both older and younger adults had similar positive clinical outcomes. Nurses need to individualize their care to patients of all ages rather than develop specific clinical guidelines for older adults with HIV.

Age Factors↗

PubMed2003

Beta 1-adrenergic receptor polymorphisms and antihypertensive response to metoprolol.

OBJECTIVES: Marked interpatient variability exists in blood pressure response to beta-blocker monotherapy. We tested the hypothesis that 2 common polymorphisms in the gene for beta(1)-adrenergic receptor are associated with antihypertensive response to metoprolol in patients with uncomplicated hypertension. METHODS: Forty hypertensive men and women aged 35 to 65 years were studied. Baseline studies included 24-hour ambulatory blood pressure monitoring. Patients took 50 mg metoprolol twice daily with weekly titration to response or 200 mg twice daily. After a minimum of 4 weeks at stable dose, treatment phase 24-hour ambulatory blood pressure monitoring was repeated. The codon 49 and 389 genotypes for beta(1)-adrenergic receptor were determined by polymerase chain reaction with restriction fragment length polymorphism. Multilinear regression was performed to determine the impact of genotype and other variables on blood pressure response to metoprolol. RESULTS: Patients homozygous for Arg at codon 389 had a nearly 3-fold greater reduction in daytime diastolic blood pressure (-13.3% +/- 8.4% versus -4.5% +/- 8.2%, P =.0018) compared with those who carried the variant allele. The haplotype pair (diplotype) for beta(1)-adrenergic receptor was also a significant predictor of response, with patients having the Ser49Arg389/Ser49Arg389 diplotype demonstrating a decline in blood pressure of 14.7 mm Hg versus 0.5 mm Hg in patients with the Gly49Arg389/Ser49Gly389 diplotype. In multiregression analysis, baseline daytime diastolic blood pressure, codon 389 genotype, and codon 49 genotype were significant predictors of blood pressure after treatment. CONCLUSIONS: Our data suggest that beta(1)-adrenergic receptor polymorphisms are important determinants of antihypertensive response to metoprolol. In the future, codon 49 and 389 genotypes or beta(1)-adrenergic receptor haplotypes might be used to predict the diastolic blood pressure response to metoprolol in patients with hypertension.

Adrenergic beta-1 Receptor Antagonists↗

PubMed2002

Complex sampling designs and statistical issues in secondary analysis.

Conducting secondary analysis using large national survey data sets to answer pressing research questions is gaining acceptance in the nursing science community. There are, however, challenges confronted by researchers who wish to apply secondary analysis to large data sets due to the incorporation of complex sampling designs. This article presents sampling design issues inherent in many large national surveys and explains the rationale for applying sample and variance estimation weights when conducting statistical analyses. In addition, the rationale for using statistical software packages capable of analyzing data derived from complex sampling designs is described. Examples of differences in statistical outcomes with and without weights using Stata and SPSS are provided using data from the Medical Expenditure Panel Survey (MEPS). Based on the example analyses, the implications of the statistical outcome differences for study findings are discussed.

Data Collection↗

PubMedDate not supplied

Suicide among African Americans: reflections and a call to action.

Suicide among African Americans is increasing at an alarming rate, and it deserves attention from numerous sectors in the society. This paper discusses some of the historical issues related to mental health care and African Americans. It suggests that sociocultural contexts are significant developmental shapers in the lives of African Americans. Several theoretical perspectives on suicide are presented, and Durkheim's concept of fatalism is useful in helping to unravel the dynamics of suicide. Issues related to the mental health system as currently experienced by African Americans conclude the discussion, along with a brief list of helpful resources.

Adolescent↗

PubMedDate not supplied

Depression among southern rural African American women: a factor analysis of the Beck Depression Inventory-II.

BACKGROUND: This is the first reported study involving a factor analysis of the Beck Depression Inventory-II, which was administered to a sample of southern rural African American women. OBJECTIVE: To determine the factor structure of the Beck Depression Inventory-II using data collected from southern rural African American women. METHODS: Using a correlational, descriptive design, 206 southern rural African American women were invited to participate in a face-to-face interview that occurred in a variety of community-based settings. RESULTS: The factor analysis of the Beck Depression Inventory-II resulted in a two-factor solution. Symptoms such as pessimism and worthlessness loaded high on the first factor (cognitive). The second factor explained somatic-affective symptoms of depression, with factor loadings high on tiredness and fatigue and loss of energy. CONCLUSIONS: The application of the Beck Depression Inventory-II among African American people would generate needed information about how depressive symptoms may be expressed among them. Knowledge gained from this study promises to be useful for developing appropriate research studies and population-specific treatment approaches for this group of women.

Adult↗