PubMed Health⌕ Search

Biomedical subjects

N Markovic

Publications and source records attributed to N Markovic.

32 records · Page 2Linked to original sources
PubMed1998

John Henryism and blood pressure among Nigerian civil servants.

STUDY OBJECTIVE: Among urban Nigerian civil servants, higher socioeconomic status is related to increased blood pressure. In the United States, the relation between increased blood pressure and low socioeconomic status or low level of education has been found to be potentiated by high effort active coping (John Henryism) among African-Americans. Thus, the potentiating effect of high effort active coping as measured by the John Henryism Active Coping Scale, on socioeconomic status, as measured by job grade, was considered in relation to blood pressure in a Nigerian civil servant population. DESIGN: The influence of John Henryism on the association between educational level or socioeconomic status and increased blood pressure was examined during a comprehensive blood pressure survey. John Henryism refers to a strong behavioural predisposition to actively cope with psychosocial environmental stressors. SETTING: Benin City, Nigeria. PARTICIPANTS: Nigerian civil servant sample of 658 adults, aged 20 to 65 years. MAIN RESULTS: Among those with high John Henryism scores of upper socioeconomic status, whether measured by education level or job grade, there was a trend toward higher systolic and diastolic blood pressures, adjusted for age and body mass index, in men and women, though not statistically significant. CONCLUSIONS: This trend is consistent with recent findings of increased blood pressure among women and African-Americans with high John Henryism and high status jobs.

Adaptation, Psychological↗
PubMed1997

Test-retest reliability of the cognitive lifetime drinking history.

A new measure of lifetime alcohol consumption, the Cognitive Lifetime Drinking History (CLDH) uses beverage-specific questions on drink sizes and assesses drinking patterns to enhance recall. Two methods of establishing drinking intervals were examined: 1) floating--the respondent's report of when drinking changed, and 2) fixed--defined in terms of decades. Test-retest reliability for lifetime ounces of alcohol consumed and times intoxicated in lifetime estimated at visits 1 week or more apart was assessed in postmyocardial infarction patients (n = 81) and controls (n = 138) who had had at least 12 drinks in a year during their lifetimes. No significant differences in estimates of lifetime ounces of alcohol or times intoxicated were observed. Spearman's r ranged between 0.85 and 0.92 for the floating and fixed versions of the CLDH administered at a single visit and between 0.74 and 0.85 for the floating or fixed administered at both visits. Time between visits did not influence correlations. Intervals reported on the floating CLDH were comparable for postmyocardial infarction patients and controls. It took approximately 5 minutes longer to administer the floating CLDH than the fixed CLDH. Findings support use of the CLDH for case-control studies and suggest that the floating and fixed versions would yield comparable results.

Adult↗
PubMed1997

Do men become infertile after having sexually transmitted urethritis? An epidemiologic examination.

OBJECTIVE: To critically assess the possibility that gonorrhea or chlamydia causes male infertility. DESIGN: Comprehensive literature review structured to evaluate the epidemiologic tenets for causality, including biologic plausibility, strength of association, dose response, consistency, temporality, and treatment effect. RESULT(S): It is biologically plausible that gonorrhea and/or chlamydia could cause male infertility. There is clinical and pathologic evidence linking these pathogens to urethritis, linking urethritis to epididymo-orchitis, and linking epididymo-orchitis to infertility. Retrospective epidemiologic results also support an association between chlamydia serologies and male infertility, which in most of these small studies does not reach the level of statistical significance. However, there is no consistent epidemiologic evidence that these pathogens alter sperm characteristics. We discuss the methodologic limitations of previous epidemiologic studies and suggest strategies for future research. CONCLUSION(S): Whether gonorrhea and/or chlamydia cause male infertility is currently unclear. Sound methodologic research strategies must be applied to future studies.

Chlamydia Infections↗
PubMed1996

Correlates of serum lipids in a lean black population.

Exposure to an urban, sedentary work environment and higher socioeconomic status (SES) may stimulate adoption of Westernized lifestyles by populations in developing countries reversing the historically low risk for coronary heart disease. In a study of serum lipids in 1407 Nigerian civil servants, aged 25-54 years, we found a more atherogenic lipid profile among higher SES males and females compared with lower SES (LDL-cholesterol, 113 vs. 97 mg/dl, males, 125 vs. 114 mg/dl, females). Mean body mass index (BMI, kg/m2) in higher and lower SES was 22.6 and 21.3, respectively, males, and 24.7 and 24.4, respectively females. A strong relationship was observed between BMI and lipids although this relationship was absent among the leanest half of the population (BMI < 21.8). In multiple regression, SES and BMI were both strong and independent predictors of cholesterol. Both high and low SES consumed a typical Nigerian low fat, high carbohydrate diet, but somewhat higher meat, milk and egg intake suggested that some Westernization of the diet had occurred among the higher SES. Physical activity was lower among the higher SES. We conclude that SES related changes in lifestyle contribute to substantially higher total and LDL-cholesterol even in a generally lean population consuming a low fat diet.

Adult↗
PubMed1996

Relationship of hypertension to socioeconomic status in a west African population.

OBJECTIVES: To determine whether hypertension rates were positively related to socioeconomic status (SES) in males in urban northern Nigerian civil servants in order to confirm this relationship previously observed in a southern Nigerian civil servant population which differed in tribal origin, religious practices and diet. METHODS: Civil servants were recruited from the Sokoto State ministries, Sokoto, Nigeria. Professionals and administrators were designated as higher SES, and clerks and laborers as lower SES. In addition to blood pressure, the height and weight of individuals, as well as their urinary sodium- and potassium-creatinine, were also measured. RESULTS: The age-adjusted occurrence of hypertension (systolic pressure > or = 140 mmHg or diastolic pressure > or = 90 mmHg or current use of hypertension medication) was similar in male higher (n = 155) and lower (n = 255) SES groups aged 25-54, 19.3% and 19.8%, respectively. However, the age-adjusted rate of definite hypertension (systolic pressure > or = 160 mmHg or diastolic pressure > or = 95 mmHg or current use of hypertension medication) was considerably higher in the higher SES than in the lower SES men, 11.2% versus 3.6%. Age-adjusted body mass index (BMI, kg/m2) was higher among the higher than in the lower SES group, 21.4 versus 20.4. Over-night sodium excretion did not differ. Among female civil servants (n = 73) aged 20-44, there were few of higher SES (n = 19) precluding SES-specific analyses. Total and definite hypertension rates among women were 17.2% and 5.5%, respectively. Mean BMI was 22.2. In logistic regression, definite hypertensive status was related to age group, BMI tertile, sodium excretion and SES in men and to sodium excretion in women. CONCLUSION: Even in this very lean population, the higher risk for hypertension in males of higher SES was confirmed. This was explained, in part, by higher BMI.

Adult↗
PubMed1995

Blood pressure reactivity to stress varies by hypertensive status and sex in Nigerians.

Previous studies among American and European populations have demonstrated larger blood pressure responses to behavioral challenges among men and hypertensive individuals. This is the first report of cardiovascular responses to behavioral challenges in a West African population. Blood pressure and heart rate changes in mirror image tracing and speech making tasks were recorded for 787 Nigerian civil servants participating in a comprehensive blood pressure survey conducted in Benin City, Nigeria, during 1992. Similar to findings in other populations, greater task-induced increases in systolic blood pressure (SBP) and diastolic blood pressure (DBP) were present among men than women (mean values of SBP = 22.1 vs. 18.3 mmHg, p < 0.001; and DBP means = 13.3 vs. 11.2 mmHg, p < 0.0001) and among hypertensives than normotensives (SBP means = 27.6 vs. 19.2, p < 0.0001; and DBP means = 14.1 vs. 12.1 mmHg, p < 0.05). An elevated prevalence of hypertension among men of higher staff status has been found in this population; however, higher staff status was not consistently related to cardiovascular reactivity, independent of hypertensive status. Additionally, hypertensive men who had speech-induced increases of SBP > 40 mmHg had significantly greater left ventricular mass index than did those hypertensive men with smaller SBP increases (p < 0.04). This study demonstrates that measures of cardiovascular reactivity to behavioral challenges have cross-cultural application, suggesting the need for further investigations of the interrelation of hypertension, cardiovascular reactivity, and left ventricular mass.

Adult↗
PubMed1994

Adequacy of a single visit for classification of hypertensive status in a Nigerian civil servant population.

BACKGROUND: Concern has been expressed regarding the adequacy of classifying individuals as hypertensive based upon a single blood pressure determination and/or the average of readings taken at a single visit and the appropriateness of these determinations in cross-cultural comparisons of rates of hypertension. METHODS: This analysis investigated the potential classification variability by comparing hypertensive status determined by 1) a single reading, 2) an average of the second and third determination at the first visit, and 3) an average of the second and third determinations obtained at each of three visits according to a standardized protocol. Kappa statistic, sensitivity and specificity were calculated to assess the agreement of hypertension classification for 804 subjects in the Health Survey in Nigerian Civil Servants, Benin City, 1992. Data were also compared to other published studies for variability in hypertension classification with repeated blood pressure determinations. RESULTS: Good to excellent agreement was observed for the entire population between the single blood pressure determination, the average of the first visit, and the average of three visits. Sensitivity and specificity measures were also acceptable for the entire population. Further analysis by sex and staff status (a measure of socioeconomic status) found no apparent distinctions between the groups. CONCLUSION: Contrasting the data with other published studies, conducted in both developed and developing countries, we note no greater variability in repeated blood pressure measurements, and conclude that the average of blood pressure determinations at a single visit in this working urban population is adequate for determining hypertensive status for comparisons with hypertension rates in Westernized populations.

Adult↗
PubMed1994

A new assay for intracellular measurement of inosine monophosphate dehydrogenase activity: a guide for better selection of patients for enzyme-targeted chemotherapy.

We developed a new cytochemical assay for identification of cells containing inosine monophosphate dehydrogenase (IMPDH) and measurement of tumor cell sensitivity to the escalating dose/schedule of the IMPDH pattern-targeting drugs. The assay is based on cytochemical principles for development of DH activity markers inside morphologically classified cells, image analysis for measuring the amount of this marker, and computer assistance for data management. The assay was optimized on a human leukemia cell line (K562-NS) and reference values for enzyme activity were established. Assay specificity was determined with different substrates and enzyme inhibitors. Sensitivity depends on the measuring instrument (image analyzing system), and the precision of the biological model used for assessment of reference values was high. IMPDH-positive malignant cells were found in all specimens obtained from acute leukemia and solid tumor patients (13/13 and 29/29) and in four human tumor cell lines (K562, K562-NS, HL60, and HL60-M). Cells of the K562-NS line were exposed to tiazofurin and ribavirin in conventional assays for assessment of drug-induced acute and subacute toxicity/sensitivity. A reduction of IMPDH activity was recorded at drug concentrations below the range at which cell damage appeared.

Acute Disease↗
PubMed1977

Enzyme kinetics in single cells: concept and model.

We describe a technique whereby it is possible to measure enzyme activity in a singel cell. The model chosen involved the measurement of myeloperoxidase activity in a polymorphonuclear neutrophil leukocyte. Details of the apparatus are described. The experiments necessary to optimize the reaction conditions are summarized. The nature of the phases of the reaction are described. The technique appears to have further application in measurement of the activities of other enzymes in leukocytes or other cells.

Densitometry↗
PubMedDate not supplied

Cervical acid phosphatase: a biomarker of cervical dysplasia and a potential surrogate endpoint for colposcopy.

BACKGROUND: In 2000, cervical acid phosphatase (CAP) has been recently described as a biomarker labeling abnormal squamous cells on Pap smears (USPTO #6,143,512). The enzyme activity is presented as a red, granular deposit on a modified Papanicolaou background. This unique property was utilized for development of MarkPap technology intended for cervical cancer screening. MATERIAL/PATIENTS & METHODS: We conduct a multicenter, random assignment, assessor blinded, 2-group (test and control), split-sample designed clinical trial on 1,500 subject/specimens to assess safety and efficacy of the new test, in comparison with the control, for cervical cancer screening in standard Pap test environment. Safety is measured with frequency, severity and relation of adverse events. Efficacy is measured with primary endpoints (portion of positive/abnormal specimens detected, and the false negative rate). At the end of the follow-up period (two years) when the study will be completed, other efficacy endpoints such as accuracy (sensitivity/specificity) and predictive values will be added to the method evaluation. Here we present in interim analysis. RESULTS: In April 2003, the recruitment was completed and the first twelve hundred cases have been evaluated. There was no serious or related adverse event in both groups. Minor, unrelated adverse events were rare and insignificantly distributed in both groups. PRIMARY ENDPOINTS: A: Portion of positive/abnormal specimens detected: Pe (new test) = 0.166, Ps (Pap control): 0.082; Ps' (ACS reported value for US in year 2000): 0.07. Pe >/= Ps + delta, for delta = 0.5Ps. B. False negative rate: Pe = 0.05, Ps' = 0.10. Confidence intervals: 95% CI: Test [0.148-0.193], Pap control [0.068-0.098]. OR = 2.26. chi2 = 40.69101 is greater than the critical value of 3.841 (P < 0.01). CONCLUSION: We concluded that CAP had added to visibility of Pap test and has enabled cytoscreeners to significantly improve the detection of positive/abnormal specimens and reduce false negative rate. We discuss this unique property of CAP with emphasis on using it as a surrogate endpoint for colposcopy and eventual removal of a cervical lesion that, if untreated, could progress into cancer.

Acid Phosphatase↗
PubMedDate not supplied

Summary statement on quantitative cytochemistry (DNA and molecular biology): Task Force 8.

OBJECTIVE: To reach consensus on the application of quantitative cytochemical analysis of chromosomal and DNA aneuploidy in cervical cytopathology. CONCLUSION: The current Pap test has limited specificity to predict cancer and its truly progressive pre-malignant lesions. Infection with human papillomavirus may trigger genetic instability, hyperproliferation and immortalization of the cervical mucosa and cause cervical cancer. Several related molecular markers have been shown to be informative about this neoplastic process. Quantitative analysis of chromosomal and DNA aneuploidy has been shown to be an important tool for identifying (progression to) high grade squamous intraepithelial lesions. A high degree of standardization (material handling, calibration and quality control, measurement and interpretation of results) is required for accurate and reproducible measurements. Areas for further study are presented.

Aneuploidy↗