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PubMed2002

Identification and review of sensitivity analysis methods.

Identification and qualitative comparison of sensitivity analysis methods that have been used across various disciplines, and that merit consideration for application to food-safety risk assessment models, are presented in this article. Sensitivity analysis can help in identifying critical control points, prioritizing additional data collection or research, and verifying and validating a model. Ten sensitivity analysis methods, including four mathematical methods, five statistical methods, and one graphical method, are identified. The selected methods are compared on the basis of their applicability to different types of models, computational issues such as initial data requirement and complexity of their application, representation of the sensitivity, and the specific uses of these methods. Applications of these methods are illustrated with examples from various fields. No one method is clearly best for food-safety risk models. In general, use of two or more methods, preferably with dissimilar theoretical foundations, may be needed to increase confidence in the ranking of key inputs.

Analysis of Variance↗
PubMed2002

[C-peptide as the decisive factor for classification of type 1 diabetes mellitus and type 2 diabetes mellitus].

OBJECTIVE: The main objective was to seek, based on defined groups of diabetics, C-peptide levels on fasting and after stimulation which would help to differentiate diabetes mellitus type 1 from diabetes mellitus type 2 in patients with manifestation of diabetes in adult age. GROUPS: Group A comprised 65 non-obese diabetics type 2 with failure of PAD treatment. Group B included 304 newly manifested diabetics type 1 and 2 aged 31-65 years. Group C was formed by 424 patients with diabetes mellitus type 1 and type 2 with different duration of diabetes. RESULTS: Group A: mean C-peptide levels on fasting 0.32 and after stimulation with a standard breakfast 0.59 pmol/ml suggest absolute insulin deficiency in type 2 diabetics with failure of PAD treatment. Group B: 29.2% diabetics type 1 had already during manifestation of diabetes C-peptide levels on fasting < 0.43 pmol/ml and 47.9% C-peptide of < 0.6 after a meal. There were 1.9 and 4.9% subjects among type 2 diabetics with such low C-peptide levels. After a six-year follow up the mean C-peptide levels on fasting declined in type 1 diabetics from 0.49 to 0.16 pmol/ml and in patients originally with type 2 diabetes reclassified to type 1 the levels dropped from 0.56 to 0.26 pmol/ml. Group C served as the basic group for statistically (linear regression method) detected discrimination values of C-peptide differentiating diabetes mellitus type 1 and diabetes mellitus type 2--the liminal value being 0.59 pmol/ml on fasting and 1.0 pmol/ml after a meal. CONCLUSION: In clinical practice it is not possible to assess reliably slowly manifesting diabetes type 1 (LADA by age, BMI and compensation of diabetes. Positivity of antiGAD antibodies does not rule out diabetes mellitus type 1. In unequivocal cases the decisive factor is therefore the C-peptide level on fasting and after a meal.

Adult↗
PubMed2003

Effect of 4-hydroxyphenylretinamide on human cervical epithelial and cancer cell lines.

Topical trans-retinoic acid treatment produced a statistically significant regression of cervical intraepithelial neoplasia (CIN) 2, but not CIN 3, in trials. A promising oral retinoid, 4-hydroxyphenylretinamide (4-HPR) induced apoptosis through non-retinoic acid-mediated pathways and is being studied in National Cancer Institute phase II trials in several organ sites. We studied the effects of 4-HPR on cervical cancer cell lines and on cervical epithelial cell lines immortalized by human papillomavirus (HPV). Four immortalized cervical epithelial cell lines (in vitro models of precancerous CIN lesions) and nine cervical carcinoma cell lines were studied. The growth inhibitory effect of 4-HPR was tested in monolayer culture and in semisolid medium, and concentrations required for a 50% growth inhibition within 5 days were determined. The agent 4-HPR inhibited the growth of cervical carcinoma cell lines and HPV-immortalized cell lines in a dose- and time-dependent fashion. Doses of 5 and 10 microM were more effective than 1 microM. The C33A cell line was most sensitive to 4-HPR, and HeLa and HT3 were the least sensitive. Of the HPV-immortalized cell lines, Z132, an HPV-16 immortalized cell line, was sensitive; the HPV 18-immortalized cell lines (Z173, Z183, and TCL-1) were not, although they were sensitive when grown in colonies. The agent 4-HPR is active against several cervical cancer cells lines and HPV-immortalized cervical epithelial cell lines. These findings are consistent with data from other laboratories studying other organ systems. This study helps establish a relevant biologically active dose for clinical trials in the cervix, one corresponding to the 5- and 10-microM tissue doses.

Cell Division↗
PubMedDate not supplied

The association of AIDS education and sex education with sexual behavior and condom use among teenage men.

According to a 1988 nationally representative survey, most 15-19--year-old men in the United States have received formal instruction about AIDS (73%), birth control (79%) and resisting sexual activity (58%). Results of multivariate analyses show the receipt of AIDS education and sex education to be associated with modest but significant decreases in the number of partners and the frequency of intercourse in the year prior to the survey. Having received instruction in these topics was also associated with more consistent condom use. Instruction in some topics was associated with increases in knowledge and attitudes about AIDS, but these increases were not always correlated with safer behavior.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Haplo-insufficiency of BRCA1 in sporadic breast cancer.

Copy number deletions and loss of heterozygosity of the BRCA1 gene have been frequently reported in sporadic breast cancer. We studied their relationship with BRCA1 gene expression (the haplo-insufficiency hypothesis) with real-time quantitative reverse transcription-PCR. Expression levels of both full-length and BRCA1-Delta 11b splice variant mRNA were studied, and they showed strong correlation (Pearson r = 0.89). Copy number deletion of BRCA1, found in 45% (27 of 60) of the sporadic breast tumors, was associated with ErbB2 oncogene amplification (P = 0.001) and DNA aneuploidy (P = 0.037), but not with stage, grade, or hormone receptor status. The presence of BRCA1 copy number deletion associated significantly with low levels of full-length BRCA1 mRNA (P < 0.0001). The BRCA1 promoter hypermethylation, found in 6 of 53 tumors (11%) by methylation-specific PCR, was also correlated with low BRCA1 expression (P = 0.005). In statistical multiple regression analysis, decreased expression of BRCA1 mRNA showed strongest association with BRCA1 copy number deletion (P < 0.0001) but was also significantly linked to negative progesterone receptor status (P = 0.02) and BRCA1 promoter hypermethylation (P = 0.041). These findings demonstrate that deletion of the BRCA1 gene copies results in haplo-insufficiency, i.e., decreased BRCA1 mRNA expression. This, in turn, suggests that the BRCA1 gene might have a tumor suppressor function also in sporadic breast cancer.

Breast Neoplasms↗
PubMed1998

Wisconsin Card Sorting Test performance in above average and superior school children: relationship to intelligence and age.

This study explores the relationship of intelligence and age to scores on the Wisconsin Card Sorting Test, a measure of executive function. A sample of 26 normal children with Wechsler Intelligence Scale for Children-III (WISC-III) Full-Scale IQS above 130 and 24 normal children with WISC-III Full-Scale IQS between 110 and 129 were administered the test. A comparison to published norms revealed that above average children outperformed the average 9- to 14-year-old child on every measure at every age. Multiple regression analyses statistically related the Wisconsin Card Sorting Test, perseverative, nonperseverative, total errors, and trials to the first category of intelligence. Intelligence proved to be a significant qualifier of age trends. Gender relationships were nonsignificant in a preliminary analysis.

Journal Article↗
PubMed2004

Prenatal patients' views of prenatal care services: a medical center-based assessment of knowledge and intent to use support services.

BACKGROUND: Our objective was to ascertain the priority of prenatal support services from the perspective of high-risk patients. The relationship between patients' needs, and both knowledge of and intent to use services, was examined, while documenting factors associated with the intent to use available support services. METHODS: The authors of this study conducted a cross-sectional survey of 102 African-American women at a university-affiliated, urban-health center. Patients' priority support needs were compared to their knowledge of and intent to use support services using chi-square statistics. Logistic regression was used to determine factors independently associated with patients' intent to use 5 support services (substance abuse counseling, community referrals, health education, nutrition services, and social work services), while adjusting for potential socioeconomic confounding variables, knowledge, and need for services. RESULTS: Knowledge of existing services was independently associated with patient intent to use one or more support services (odds ratio 3.6; confidence interval 1.4-9.4). With each one-unit increase in parity, a 30% less odds (odds ratio 0.7; confidence interval 0.4-0.9) of using one or more support services occurred. CONCLUSIONS: Physicians should ensure prenatal patients' knowledge of support services at healthcare centers. Multiparity is inversely related to women's intent to use support services, independent of their knowledge of service availability.

Academic Medical Centers↗
PubMed2004

Costs and utilization associated with pharmaceutical adherence in a diabetic population.

OBJECTIVE: To determine whether adherence with pharmaceutical therapy affects well being and total costs associated with diabetes treatment. STUDY DESIGN: Retrospective cohort design using insurance claims in an open access, nonmanaged care setting. PATIENTS AND METHODS: Patients with diabetes were under age 65 years, continuously enrolled with medical and drug eligibility, and identified by using methodology based on the Health Employer Data and Information Set. Patients were identified in 1998. The level of adherence to drugs used for diabetes, utilization, and medical costs were measured in 1999. Regression analyses statistically controlled for age, sex, illness severity, and product line. RESULTS: Of the 57,687 patients identified with diabetes, 55% were male and 90% were age 40 years or older. Study members taking a prescription medicine for diabetes were significantly older and marginally sicker than those not taking a prescription medicine for diabetes. Patients without diabetic drug claims had the lowest medical costs, whereas younger patients and female patients had higher costs and utilization. A threshold effect was observed, where a target level of adherence was needed before medical care costs were reduced. Increased pharmaceutical adherence was associated with fewer emergency department visits and inpatient admissions. Increased medication adherence was associated with decreased medical care costs. Increased medication adherence was not associated with decreased overall healthcare costs because medication costs offset medical care cost savings. CONCLUSION: Increased adherence with pharmaceutical therapy was associated with decreased use of medical care services, suggesting improved disease control and well being, but not with lower costs.

Adolescent↗
PubMed1992

Age at menarche and associated nutritional status variables in Karimui and Daribi census divisions of Simbu Province.

Age at menarche was estimated from data on 310 girls and young women living in Karimui and Daribi census divisions of Simbu Province in 1987. The area has high malnutrition rates among children under five years of age and short adult female stature suggesting that onset of menses should be late. However, other work has shown young ages at the birth of first children and high overall fertility rates among women. The prediction of age at menarche from adult female height is not valid for this population; the actual age at which 50% of girls had commenced menstruating is approximately one and a half years earlier, at 15.8 years, than the predicted age. The nutritional status variables investigated and found to be associated with the age at menarche are height, weight and triceps skinfold thickness. At any given age girls whose nutritional status was better, particularly in terms of weight, were more likely to have commenced menstruation. Menarche appears to be followed closely by onset of reproductive function, with the age at the birth of first children estimated at 17.2 years. A consequence of early entry into reproduction, particularly for girls in areas where undernutrition is common, is a period of considerable nutritional stress during adolescence. Intervention programs should consider this and target these groups for additional health, family planning and nutritional advice.

Adolescent↗
PubMed1992

Rapid bedside method to assess changes in postoperative fluid status with bioelectrical impedance analysis.

BACKGROUND: Estimates of daily postoperative fluid balance usually rely on properly recorded inputs, outputs, and daily weights or clinical signs. These may be imprecise (when poorly done) and are often considered tedious to perform. METHODS: We used bioelectric impedance analysis (BIA) to assess changes in body water shifts in cardiac patients after surgery. Nine consecutively admitted patients undergoing coronary artery bypass (seven men and two women; age range, 43 to 67 years) were studied. Body weight, fluid intake and output, and BIA variables (resistance and reactance) were measured daily. Relationships between body weight and changes in resistance and reactance and net change in fluid balance (in liters per day) were evaluated statistically by regression analysis. RESULTS: Mean body weights changed significantly, reflecting early operative fluid accumulation and later postoperative diuresis; net fluid balance correlated poorly (r = 0.48; p less than 0.05) with body weight, whereas both resistance (r = -0.82; p less than 0.001) and reactance (r = -0.92; p less than 0.0001) correlated highly with net fluid balance. CONCLUSIONS: BIA is useful as an accurate, rapid bedside method for assessing changes in hydration status sequentially after surgery in cardiac patients with complicated fluid shifts.

Adult↗
PubMedDate not supplied

Further clues to recognition of patients with fibromyalgia from a simple 2-page patient multidimensional health assessment questionnaire (MDHAQ).

OBJECTIVE: To analyze quantitative scores for pain, fatigue, functional disability, and the number of symptoms on a review of systems on a multidimensional health assessment questionnaire (MDHAQ), including the ratios of scores for pain to physical function and fatigue to physical function, and to further study how these scores can help to identify patients with fibromyalgia. METHODS: All consecutive patients seen at a rheumatology clinic completed a 2-sided, 1-page MDHAQ at each visit to assess physical function, pain, fatigue, global status, helplessness and review of systems, and had their erythrocyte sedimentation rate (ESR) measured. Scores for these variables were analyzed in 78 consecutive patients with fibromyalgia over a two-year period, and in 149 patients with rheumatoid arthritis (RA) as a "control" group. A subset analysis was conducted in patients with RA who were classified independently according to clinical criteria as having or not having coexistent fibromyalgia. Descriptive statistics, logistic regression, and receiver-operating-characteristic curves were computed for patients with fibromyalgia and compared to patients with RA. RESULTS: Patients with fibromyalgia had high ratios of pain:physical function and fatigue:physical function scores, and a high number of reported symptoms. These quantitative data differed significantly from patients with RA. Patients with fibromyalgia also had a lower ESR than patients with RA, whose scores were similar whether or not there was coexistent fibromyalgia. Patients with fibromyalgia were distinguished equally well from patients with RA by patient questionnaire data as by the ESR. CONCLUSION: A simple 1-page, 2-sided patient questionnaire provides quantitative information which may contribute to identify patients with fibromyalgia, including patients with RA who may also have coexistent fibromyalgia.

Blood Sedimentation↗
PubMed2004

Radiation therapy of small cell lung cancer with 177Lu-DOTA-Tyr3-octreotate in an animal model.

UNLABELLED: Small cell lung cancer (SCLC) is a tumor of neuroendocrine (NE) origin with very low survival rate. Somatostatin receptor scintigraphy using 111In-DTPA-octreotide (DTPA is diethylenetriaminepentaacetic acid) is a well-established method for the visualization of somatostatin receptor-expressing NE tumors. Recently, new combinations of radionuclides and somatostatin analogs have been investigated for therapeutic purposes. In this study, the somatostatin analog DOTA-Tyr3-octreotate (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid), labeled with the medium-energy electron emitter 177Lu (maximal electron energy = 498 keV, half-life = 6.6 d), was used for radiation therapy of human SCLC in an animal model. METHODS: Nude mice, bearing tumors from the human SCLC cell line NCI-H69, were injected intravenously with 177Lu-DOTA-Tyr3-octreotate. Groups of animals (n = 5 or 6) were injected with 45-, 60-, and 120-MBq fractions and two 45-MBq fractions 48 h apart. Furthermore, 1 control group was treated with unlabeled DOTA-Tyr3-octreotate and another control group was not treated. RESULTS: In both control groups, the tumor volumes were increased 2-fold in approximately 5 d. Treatment with 177Lu-DOTA-Tyr3-octreotate resulted in marked tumor regression with statistically significant tumor volume reduction after 1 wk (P < 0.001). The tumor growth delay time was dependent on the amount of injected activity for the groups with single injections, 26 d for 60 MBq and 40 d for 120 MBq. The best therapeutic effect was obtained in mice injected with 2 fractions of 45 MBq. The relative tumor volume after 1 mo was 0.004 +/- 0.004. CONCLUSION: Radiation therapy with 177Lu-DOTA-Tyr3-octreotate on SCLC-bearing mice was successful. Since the experiments were performed on a human SCLC cell line xenografted to nude mice, the results may be clinically relevant and treatment with 177Lu-DOTA-Tyr3-octreotate could be a treatment alternative in this tumor disease that normally has a dismal prognosis.

Animals↗
PubMedDate not supplied

Clinical and familial correlates of tardive dyskinesia in India and Israel.

BACKGROUND: Antipsychotic drugs are widely used for the treatment of psychosis, especially schizophrenia. Their long-term use can result at times in serious side-effects such as Tardive Dyskinesia (TD). Since over 80% of schizophrenia sufferers (lifetime prevalence 1%) receive long-term antipsychotic drug treatment, the extent of the problem is potentially large. Increasing age is the most consistently demonstrated risk factor for TD. AIMS: To assess effect of different clinical factors and demographic variables in India and Israel and sib pair concordance of Tardive Dyskinesia (TD) in India. SETTINGS AND DESIGN: The study was conducted simultaneously among Indian and Israeli subjects: ascertainment was family-based in India and hospital-based in Israel. METHODS AND MATERIAL: In India the instruments used were: Diagnostic Interview for Genetic Studies (DIGS), Positive and Negative Syndrome Scale (PANSS), Abnormal Involuntary Movement Scale (AIMS), and Simpson Angus Scale (SAS). The last three instruments were also used in Israel. STATISTICAL ANALYSIS: Regression analysis and Pearson's correlation. RESULTS AND CONCLUSIONS: TD symptoms were present in 40.4% of 151 Israeli subjects and 28.7% of 334 Indian subjects. While age at onset and total scores on PANSS were significant predictors of TD in both the samples, lower scores on the Global Assessment of Functioning Scale (GAF), diagnostic sub-group and male gender were significant predictors among Indians. There was no concordance of TD symptoms among 33 affected sib-pairs from India.

Adult↗
PubMedDate not supplied

Association between glycaemic control and quality of life in diabetes mellitus.

BACKGROUND: Relationship between quality of life (QOL) and haemoglobin A1c (HbA1c) amongst diabetics in the community setting is unclear. AIMS: Assess the association between QOL and change in HbA1c in diabetic patients over one year. SETTINGS AND DESIGN: Cohort study of patients from four community clinics in California, USA. METHODS: Diabetic patients identified from databases using International Classification of Disease (ICD-9) codes were asked to complete Short Form 36 (SF-36), which measures health-related QOL, and invited to attend monthly diabetes workshops. From December 2000 to December 2001, data were collected on multiple parameters, including HbA1c. SF-36 surveys were re-collected at project termination. STATISTICAL ANALYSIS: Regression analysis was used to correlate change in HbA1c with change in QOL physical component summary (PCS) and mental component summary (MCS) scores, while considering potential confounders. RESULTS: Of 1679 eligible patients, 380 completed SF-36 at project initiation. 243 of those completed SF-36 at project termination. Pre and post HbA1c data were available for 170 of the 243 who completed SF-36 at both times. Average MCS increased by 8.46% and PCS decreased by 2.24%. After adjustment, a 5% decrease in HbA1c values was associated with a 1% increase in MCS. No association between changes in HbA1c and PCS was observed. CONCLUSIONS: Association between better HbA1c and improved mental, but not physical, QOL may reflect physical inconvenience of increased regimen complexity and mental empowerment from proactive disease management. Larger cohort studies with longer follow-up are needed to further elucidate the relationship between glycemic control and QOL.

Cohort Studies↗
PubMed2004

Monitoring of COD as an organic indicator in waste water and treated effluent by fluorescence excitation-emission (FEEM) matrix characterization.

The fluorescence excitation-emission matrices (FEEM) of domestic waste water, treated effluent of a waste water treatment plant and receiving river water were analyzed to select wavelengths for the monitoring of organic contents as COD. Excitation/emission wavelengths of 220/350 nm and 270/350 nm for protein-like fluorescence and 240/450 nm and 340/450 nm for humic-like fluorescence were suggested as fluorescence peak emitting wavelength pairs, respectively. Without any pre-treatment, the protein-like fluorescence peaks showed better correlation between COD values and fluorescence intensities than the humic-like fluorescence peaks. No enhanced correlation was observed by removing the suspended solids from the samples using filtration. However, statistical multiple regression methods, using the fluorescence intensities from each peak and the light scattering intensity at 633 nm as variables, resulted in an enhanced correlation, with r2 > 0.9 for the measured and predicted COD values.

Environmental Monitoring↗
PubMed2005

Prognostic significance of mitotic and apoptotic index and the DNA cytometry in head and neck cancer.

The lack of suitable criteria to predict the response to chemo- and or radiotherapy for individual patients with squamous cell carcinoma of the head and neck (HNSCC) remains still a major problem. This study was conducted to analyze prognostic significance of mitotic and apoptotic index and the DNA flow cytometric analysis of HNSCC to the recurrence-free survival time and to the overall survival. The analysis was carried out in a set of 56 patients suffering from carcinoma of the pharynx and supraglottis. Most patients (96.7%) underwent neoadjuvant chemotherapy, followed by surgery and postoperative irradiation. Besides routine examinations, flow cytometric analysis was performed, as well as p53 and Ki-67 markers and mitotic and apoptotic index were established by means of immunohistochemistry. Event-free survival (EFS) and overall survival (OS) were accepted as primary endpoints for the prognostic analyses. All the examined potential markers entered standard Kaplan-Meier survival analysis and Cox regression modeling. Statistical significance of prognostic factors was first examined in univariate models and all the parameters subsequently entered multivariate models. The analyses revealed significant prognostic position of advanced clinical stage (III+IV) and increased proliferative activity as primary risk factors (p<0.01) that typically positively correlate with increased mitotic activity and G2/M cell fraction. Better survival results obtained for grade 3-4 as compared to grade 1-2 were caused by molecular parameters that make these samples similar to less risk cases. Cytokinetic parameters and proliferation activity were found as important predictors of the second level (after recognizing stage, grade and DNA status of the tumor). Multivariate combination of these markers contributed namely to the prognosis of early risk event: a ratio S phase cell fraction/G2M cell fraction was found to be the key prognostic factor (p<0.01). Early risk events are associated with increased mitotic activity, decreased apoptic rate, decreased S phase cell fraction and significantly increased G2/M fraction.

Adult↗
PubMed2005

Low birth weight and cardiovascular risk factors in Auckland adolescents: a retrospective cohort study.

AIMS: To determine whether birth weight is inversely associated with cardiovascular risk factors in a multiethnic sample of New Zealand adolescents. METHODS: A retrospective cohort with birth weight collected from hospital records of 855 (68%) out of 1260 Auckland-born students who had blood pressure, fasting blood lipids, and glucose measured while in Year 11-13 at high school. RESULTS: After controlling for sex, age, and ethnicity, none of the following cardiovascular risk factors were associated with birth weight (p>0.05): systolic and diastolic blood pressure, total cholesterol, HDL cholesterol, triglycerides, and glucose. Serum cholesterol came closest to statistical significance: regression coefficient being--0.10 mmol/L (SE=0.06, p value=0.11). In contrast (after controlling for age, sex, and ethnicity), current Body Mass Index (BMI) was significantly (p<0.05) related to all above cardiovascular risk factors. The proportion of students with elevated serum cholesterol levels (top 20%) attributable to elevated BMI (>30 kg/m2) was 18%, and that attributable to low birth weight (<2.5 kg) was 2%. CONCLUSIONS: These results do not support for the 'fetal origins' hypothesis. The very low proportion of adolescents with elevated coronary risk factors attributed to low birth weight suggests that the focus of cardiovascular disease prevention should remain in adolescence and adulthood, rather than in pregnancy.

Adolescent↗