Biomedical subjects

Ilya Novikov

Publications and source records attributed to Ilya Novikov.

17 recordsLinked to original sources

PubMed2006

Risk of thyroid cancer after childhood exposure to ionizing radiation for tinea capitis.

BACKGROUND: The thyroid gland is known to be sensitive to the carcinogenic effect of ionizing radiation, especially in children. The role of potential modifiers of the risk and latency period effects needs further investigation. We examined the effect of low doses of ionizing radiation (4.5-49.5 cGy) on the risk of developing thyroid cancer after long latent periods of up to 54 yr after childhood exposure. METHODS: The study population included 10,834 individuals irradiated against tinea capitis in the 1950s and two matched nonirradiated groups (general population and siblings) for comparison. Cancer statistics and vital status data were obtained from national registries, updated to December 2002. Excess relative and absolute risks [excess relative risk per gray (ERR/Gy), excess absolute risk (EAR)] were estimated using Poisson regression for survival analysis. RESULTS: Within the study period, 159 cases of thyroid cancer were diagnosed. Total ERR/Gy and excess absolute risk per gray per 10(4) person-years for developing thyroid cancer reached 20.2 (95% confidence interval 11.8-32.3) and 9.9 (95% confidence interval 5.7-14.7), respectively. The risk was positively associated with dose and negatively associated with age at exposure. ERR/Gy was significantly elevated 10-19 yr after exposure, peaking at 20-30 yr, and decreasing dramatically (although still significantly elevated) 40 yr after exposure. CONCLUSIONS: Our findings agree with patterns of risk modification seen in most studies of radiation-induced thyroid cancer, although risk per unit dose seems higher. Our data show that 40 yr after irradiation, ERR decreases dramatically, although remaining significantly elevated. The hypothesis of different genetic susceptibility of the Jewish population deserves further exploration.

Adolescent↗

PubMed2006

A community study on emotional distress among Arab and Jewish Israelis over the age of 60.

BACKGROUND: The elderly constitute a vulnerable group for psychopathology, yet research on their mental health among both Arab and Jews in Israel remains limited. The same is the case in Arab countries. This paper reports on the contrasting distribution of the mean emotional distress (ED) scores and rates of suspected clinical cases, and their related risk factors, among community residents over the age of 60. METHODS: Several national agencies conducted a survey on 5,055 elderly individuals to investigate their health status, including ED. The interview included socio-demographic and behavioral health items, as well as a modified 12 item-GHQ as a measure of ED. Total ED scores and prevalence rates for suspected psychopathology were calculated. Their respective risk factors were examined using univariate and multivariate methods. RESULTS: The ED scores were highest among Muslim Arabs (4.9), followed by Christian Arabs (4.2), Jews (3.1) and Druzes (2.8). Their estimated prevalence rates were 43.4%, 37.0%, 21.4%, and 17.0%, respectively. The gradient of these results remained unchanged in the multivariate analysis for ED scores adjusting for confounding variables. In contrast, logistic regression analysis controlling for confounding variables did not find a differential risk for suspected psychopathology between Arabs and Jews. CONCLUSION: Conceivably, the higher demoralization scores among elderly Arabs are associated with their minority status affiliation, as well as with the rapid social changes that have taken place in their midst. A cultural response style may be entertained as a possible explanation. However, these factors do not impact the risk for suspected psychopathology where no differential risk was noted after adjustments for confounders.

Age Distribution↗

PubMed2006

Health services utilization in Jerusalem under terrorism.

OBJECTIVE: The authors explored the effects of an escalation of terrorism on the help-seeking behavior of the general population in Jerusalem, a city that offers an adequate supply of medical and psychiatric services. METHOD: Time-series analyses were applied to examine the utilization of health services (primary medical care and ambulance calls) and mental health services (clinics, hospitals, and telephone hotlines) by Jerusalem residents before and during part of the current intifada. The authors assessed seasonality, general linear trends (from factors such as health education and increased access), short-term intifada impact (reflecting reactions that peaked at the third month and ended 1 year thereafter), and long-term impact (starting at the intifada outbreak and reflecting a more stable population behavior). RESULTS: Adult psychiatric outpatient visits did not change except for the elderly in ongoing care who had both short- and long-term increases. The proportion of recorded ICD-10 diagnoses reflecting intifada-related reactions remained generally stable. Short-term effects included an increase in psychiatric readmissions. First contacts to substance abuse clinics remained unchanged. While long-term effects included a decrease in new psychiatric hospitalizations, the rate of monthly general practitioner visitors and the number of monthly ambulance and hotline calls increased. CONCLUSIONS: Except for the elderly and previously hospitalized persons, Jerusalem residents did not increase their use of psychiatric services but did increase their use of some other health services. These results suggest that this terrorism-affected population did not perceive their mental and social suffering as requiring specialized intervention.

Adult↗

PubMed2005

Breast conservation after neoadjuvant chemotherapy.

BACKGROUND: Tumor downstaging by preoperative neoadjuvant chemotherapy in patients with locally advanced breast tumors allows breast conservation in women who were previously candidates for mastectomy. Nevertheless, lumpectomy success in such cases cannot be fully achieved. The aim of this study was to create a quantitative tool for preoperative evaluation of the success of breast conservation in such patients. METHODS: The study population included 100 consecutive patients with stage II and III breast cancer who were designated for lumpectomy and 19 patients who were designated for mastectomy. All patients received neoadjuvant therapy. Breast-conserving surgery was offered in accordance with clinical and esthetic criteria. Demographic details and clinical, imaging, and pathologic information were collected from medical files. A decision protocol for classifying patients to lumpectomy or mastectomy was built by using the Classification and Regression Trees procedure based on preoperative characteristics. RESULTS: Three factors were found to be the main predictors for successful breast conservation: absence of diffuse microcalcifications as seen in the pretreatment mammogram, a postchemotherapy tumor size of < 25 mm, and the existence of a circumscribed lesion on mammography. CONCLUSIONS: The use of these criteria as a basis for decision on the type of surgery may decrease the performance of unnecessary procedures.

Adult↗

PubMed2005

Modification of the computational procedure in Parker and Bregman's method of calculating sample size from matched case-control studies with a dichotomous exposure.

Several authors have addressed the problem of calculating sample size for a matched case-control study with a dichotomous exposure. The approach of Parker and Bregman (1986, Biometrics42, 919-926) is, in our view, one of the most satisfactory, since it requires specification of quantities that are often easily available to the investigator. However, its recommended implementation involves a computational approximation. We show here that the approximation performs poorly in extreme situations and can be easily replaced with a more exact calculation.

Case-Control Studies↗

PubMed2005

Genotyping of patients with sporadic and radiation-associated meningiomas.

Ionizing radiation is the most established risk factor for meningioma formation. Our aim was to evaluate the main effect of selected candidate genes on the development of meningioma and their possible interaction with ionizing radiation in the causation of this tumor. The total study population included 440 cases and controls: 150 meningioma patients who were irradiated for tinea capitis in childhood, 129 individuals who were similarly irradiated but did not develop meningioma, 69 meningioma patients with no previous history of irradiation, and 92 asymptomatic population controls. DNA from peripheral blood samples was genotyped for single nucleotide polymorphisms (SNP) in 12 genes: NF2, XRCC1, XRCC3, XRCC5, ERCC2, Ki-ras, p16, cyclin D1, PTEN, E-cadherin, TGFB1, and TGFBR2. SNP analysis was done using the MassArray system (Sequenom, San Diego, CA) and computerized analysis by SpectroTYPER. Logistic regressions were applied to evaluate main effect of each gene on meningioma formation and interaction between gene and radiation. Intragenic SNPs in the Ki-ras and ERCC2 genes were associated with meningioma risk (odds ratio, 1.76; 95% confidence interval, 1.07-2.92 and odds ratio, 1.68; 95% confidence interval, 1.00-2.84, respectively). A significant interaction was found between radiation and cyclin D1 and p16 SNPs (P for interaction = 0.005 and 0.057, respectively). Our findings suggest that Ki-ras and ERCC2 SNPs are possible markers for meningioma formation, whereas cyclin D1 and p16 SNPs may be markers of genes that have an inverse effect on the risk to develop meningioma in irradiated and nonirradiated populations.

Case-Control Studies↗

PubMed2005

Long-term follow-up for brain tumor development after childhood exposure to ionizing radiation for tinea capitis.

Ionizing radiation is an established risk factor for brain tumors, yet quantitative information on the long-term risk of different types of brain tumors is sparse. Our aims were to assess the risk of radiation-induced malignant brain tumors and benign meningiomas after childhood exposure and to investigate the role of potential modifiers of that risk. The study population included 10,834 individuals who were treated for tinea capitis with X rays in the 1950s and two matched nonirradiated groups, comprising population and sibling comparison groups. The mean estimated radiation dose to the brain was 1.5 Gy. Survival analysis using Poisson regression was performed to estimate the excess relative and absolute risks (ERR, EAR) for brain tumors. After a median follow-up of 40 years, an ERR/Gy of 4.63 and 1.98 (95% CI = 2.43-9.12 and 0.73-4.69) and an EAR/Gy per 10(4) PY of 0.48 and 0.31 (95% CI = 0.28-0.73 and 0.12-0.53) were observed for benign meningiomas and malignant brain tumors, respectively. The risk of both types of tumors was positively associated with dose. The estimated ERR/Gy for malignant brain tumors decreased with increasing age at irradiation from 3.56 to 0.47 (P = 0.037), while no trend with age was seen for benign meningiomas. The ERR for both types of tumor remains elevated at 30-plus years after exposure.

Adolescent↗

PubMed2004

The role of risk factor time trends in the steep decline of CHD mortality between two Israeli cohort studies.

BACKGROUND: Over the past few decades, a sizable monotonous decrease in coronary heart disease (CHD) mortality rates was evident in Israel. Our purpose was to evaluate the association of risk factor time trends with this decline. SUBJECTS AND METHODS: Data of two Israeli male cohorts with an inception date separated by 14 years were combined: (a) 9699 employees who participated in the Israeli Ischemic Heart Disease (IIHD) project, followed-up between 1965 and 1983, and (b) 1745 participants of the Glucose Intolerance, Obesity and Hypertension (GOH) study, sampled from the Central Population Registry, followed-up between 1979 and 1997. RESULTS: The mean age of both groups was comparable (52.9 vs. 51.2 years in the GOH and IIHD, respectively). Systolic blood pressure (133.5 vs. 138.1 mm/Hg), smoking (44% vs. 49%), and BMI (25.5 vs. 25.9 kg/m(2)) were lower in the GOH, whereas mean serum cholesterol was higher (215 vs. 208 mg/dL). During the follow-up period, 3,173 deaths were recorded. Of these, 968 (31%) were attributed to CHD. Overall mortality, adjusted by age and ethnic origin, was lower in the GOH (HR = 0.80, 95% CI: 0.72-0.89). CHD mortality was remarkably lower (HR = 0.55, 95% CI: 0.44-0.69). Adjusting for systolic blood pressure and smoking increased the HR for CHD death to 0.68 (95% CI: 0.55-0.85), whereas further adjustment for cholesterol reduced it slightly (HR = 0.63, 95% CI: 0.50-0.78). CONCLUSION: Traditional risk factors appear to play a limited role in the declining rates of CHD mortality among Israeli males.

Adult↗

PubMed2004

Clopidogrel resistance is associated with increased risk of recurrent atherothrombotic events in patients with acute myocardial infarction.

BACKGROUND: Although clopidogrel reduces the risk of cardiovascular episodes after coronary events and stenting, a substantial number of incidents continue to occur. METHODS AND RESULTS: The antiplatelet effect of clopidogrel was studied prospectively in 60 consecutive patients who underwent primary angioplasty (percutaneous coronary intervention [PCI]) with stenting for acute ST-segment-elevation myocardial infarction (STEMI) to determine whether variability in response to clopidogrel affects clinical outcomes. Patients were stratified into 4 quartiles according to the percentage reduction of ADP-induced platelet aggregation. Although patients in the first quartile were resistant to the effects of clopidogrel (ADP-induced platelet aggregation at day 6, 103+/-8% of baseline), ADP-induced aggregation was reduced to 69+/-3%, 58+/-7%, and 33+/-12% of baseline, respectively, in patients in quartiles 2 through 4 (P<0.01 for all). In addition, epinephrine-induced platelet aggregation and platelet aggregation under flow conditions, assessed by the cone-and-plate(let) analyzer method, were reduced significantly less in the first quartile than in quartiles 2 through 4. Whereas 40% of patients in the first quartile sustained a recurrent cardiovascular event during a 6-month follow-up, only 1 patient (6.7%) in the second quartile and none in the third and fourth quartiles suffered a cardiovascular event (P=0.007). CONCLUSIONS: Up to 25% of STEMI patients undergoing primary PCI with stenting are resistant to clopidogrel and therefore may be at increased risk for recurrent cardiovascular events.

Adenosine Diphosphate↗

PubMed2004

The effect of a communal lifestyle on depressive symptoms in late life.

OBJECTIVES: This study compares depression levels among lifetime kibbutz members (n = 525) and old-age kibbutz residents (n = 366) with a comparable national sample (n = 412) and assesses the relationship between depression and individual differences related to lifetime in a kibbutz (e.g., health) and those related to current living conditions (e.g., social network). METHODS: The analysis is based on data from the Cross-Sectional and Longitudinal Aging Study conducted in Israel between 1989 and 1992 and the follow-up during 1993 and 1994. RESULTS: The findings indicate significantly lower depressive symptomatology among women, but not among men, residing in kibbutz communities. The women's lower level of depressive symptoms appears to be a result of better physical and mental functioning among kibbutz members and of such favorable lifestyle characteristics as frequent contact with their children among old-age kibbutz residents. DISCUSSION: Both lifetime and current living conditions contribute to better mental health of women in the kibbutz at older ages.

Aged↗

PubMed2004

A community study on emotional distress among the elderly in Israel.

BACKGROUND: The elderly constitute a group at risk for elevated emotional distress. The Ministry of Health, the Central Bureau of Statistics and other national agencies jointly conducted a survey to investigate the health status of the elderly, including emotional distress and selective determinants. OBJECTIVE: This paper reports the distribution of the emotional distress mean scores by socio-demographic and health-related variables. METHOD: 5,055 ethnically diverse elderly residing in the community were interviewed with a questionnaire comprising socio-demographic and health promotion behavior items, in addition to the 12 item-GHQ scale. Univariate and multivariate methods of analyses were applied. RESULTS: Several variables that were associated with higher mean scores of emotional distress were identified, among them, female gender, living without a partner, and those with chronic medical conditions and impaired life-styles; 38% of the variance was explained by the study variables. CONCLUSION: Health planners and clinicians, including mental health consultants, may utilize these findings to develop individual and collective programs of intervention aimed at reducing emotional distress, particularly among the more vulnerable elderly.

Aged↗

PubMed2003

Association of elevated homocysteine levels with a higher risk of recurrent coronary events and mortality in patients with acute myocardial infarction.

BACKGROUND: Despite the prothrombotic and proinflammatory effects associated with elevated homocysteine levels, only limited data exist regarding the effect of homocysteine levels on outcome of patients with acute myocardial infarction. METHODS: Homocysteine levels were determined within 24 hours of presentation in 157 consecutive patients with acute myocardial infarction. Patients were allocated to 2 groups: those with homocysteine levels of 2.7 mg/L (20 micro mol/L) or more (n = 22 [14%]) and those with homocysteine levels of less than 2.7 mg/L (n = 135 [86%]). RESULTS: Female and diabetic patients had significantly lower homocysteine levels than males (P<.01) and nondiabetic patients (P =.005), respectively, with no significant correlation with age (r = 0.07, P =.42) or other risk factors. Patients with homocysteine levels greater than or equal to 2.7 mg/L and less than 2.7 mg/L did not differ significantly regarding extent of coronary artery disease as reflected by prevalence of multivessel disease (54% vs 61%; P =.87), and their in-hospital course. However, in a mean +/-SD follow-up of 30 +/- 10 months, patients with homocysteine levels greater than or equal to 2.7 mg/L had a higher incidence of recurrent coronary events (36% vs 17%; P =.04) and death (18% vs 5%; P<.05). Homocysteine levels greater than or equal to 2.7 mg/L remain a significant determinant of recurrent coronary event and/or death after controlling for potential cofounders by multivariate analysis (odds ratio, 3.8; 95% confidence interval, 1.3-11.0). CONCLUSIONS: In patients with acute myocardial infarction, elevated homocysteine levels are associated with a higher risk of recurrent coronary events and death, independent of other risk factors and the extent of coronary artery disease.

Aged↗

PubMed2003

Pregnancy outcome after laparoscopy or laparotomy in pregnancy.

STUDY OBJECTIVE: To assess obstetric performance and fetal outcomes after laparoscopy or laparotomy performed during pregnancy. DESIGN: Nationwide, multicenter, retrospective chart review (Canadian Task Force classification II-2). SETTING: Seventeen hospitals throughout Israel: 12 university or university-affiliated hospitals and 5 general hospitals. PATIENTS: Three hundred eighty-nine pregnant women. INTERVENTION: Laparoscopy or laparotomy for various indications. MEASUREMENTS AND MAIN RESULTS: Of 192 laparoscopies performed, 141 were during the first, 46 during the second, and 5 during the third trimester; respective figures for 197 laparotomies were 63, 110, and 24. No intraoperative complications were reported for either procedure. Six and 25 women had complications after laparoscopy and laparotomy, respectively. There was no significant difference in abortion rates between groups. Mean gestational age at delivery and mean birthweight were comparable between groups. No significant difference was found in frequency of fetal anomalies between groups or when compared with the Israel register of anomalies. CONCLUSION: Operative laparoscopy seems to be as safe as laparotomy in pregnancy.

Adult↗

PubMed2003

Second primary breast and thyroid cancers (Israel).

OBJECTIVE: To evaluate the risk for developing second primary thyroid cancer (TC) following breast cancer (BC) and second primary BC following TC on a nationwide basis. METHODS: All BC and TC Jewish females diagnosed in Israel during 1960-1998 were identified through the Israel Cancer Registry. The expected second primaries were calculated using cancer incidence rates stratified by age, country of birth and period of diagnosis among the Jewish population in Israel. Standardized incidence ratios (SIRs) were estimated using Poisson regression. RESULTS: A total of 49,207 breast and 4911 thyroid neoplasms were identified. After the exclusion of concomitant disease (diagnosed within 1 year), 59 and 70 second primaries TC and BC yielded SIRs of 1.34 (95% CI: 1.03, 1.72) and 1.07 (95% CI: 0.84, 1.34), respectively. Younger age and earlier calendar year of first primary diagnosis and shorter follow-up period were associated with increased risk for developing second primary neoplasm. CONCLUSIONS: Considering the long latency required for carcinogenesis, excess risk of second primary diagnoses soon after the first cancer, argues against the hypothesis of first primary treatment as an initiator for the second cancer. A detection bias of meticulously followed cancer patients, early exposure to common risk factors or genetic susceptibility of certain subpopulations for both malignancies seem plausible.

Adult↗

PubMed2003

The limitations of using hospital controls in cancer etiology--one more example for Berkson's bias.

The aim of this report was to present an example in which Berkson's bias, most probably, affected the results of a study by overriding the influence of a well-established risk factor (smoking) in the etiology of bladder cancer. The results of a study of 140 male patients with bladder cancer and 280 matched hospital controls confirmed the etiological role of industrial occupation in bladder cancer but failed to confirm the role of smoking. We reanalyzed the proportion of chronic related morbidity as well as the rate of smoking in patients with lung disease in cases and controls. A similar distribution of some chronic diseases known to be highly associated with smoking was found among cases and controls. Highest smoking rates (91%) were found among patients with bladder cancer who also reported a concomitant lung disease, and the lowest rate (67%) was noted among controls without lung disease (p = 0.009). Using the prevalence of smoking in the general Israeli male population (50%), significant odds ratio for bladder cancer among ever smokers compared to never smokers was observed. Our conclusion is that a possibility of Berkson's bias should be considered whenever hospital controls are used. Information on diseases related to the risk factor under consideration and on the prevalence of the risk factor in the general population, may demonstrate the existence of such a bias.

Aged↗

PubMed2003

Patterns of drug use among the community-dwelling old-old population in Israel.

BACKGROUND: Due to multiple chronic illness and disability, the elderly consume a disproportionately large share of medications. OBJECTIVES: To assess the patterns and determinants of drug use among the community dwelling old-old population. METHODS: The study population included 1,369 old-old persons from the baseline data of the Cross-Sectional and Longitudinal Aging Study (CALAS), which is based on a national random stratified sample of the Israeli Jewish population aged 75-94 years. RESULTS: The mean number of drugs used by the study population was 3.3, and only 12.5% did not consume any drugs, Multivariate linear regression analysis showed that women used significantly more drugs than men, and that those born in Europe took significantly more drugs than those born in Israel and Asia-Africa. The number of medical conditions was the strongest predictor of drug use. Hospitalizations during the last year and frequent visits to family physician were also significant factors related to drug use. All variables combined explained 40% of the variance in drug use by the old-old. The most commonly used therapeutic groups were cardiovascular drugs (53%), psychotropic drugs (31%), analgesics (30%), and gastrointestinal drugs (28%). CONCLUSIONS: Our data indicate that in addition to the association of drug use with health status and healthcare utilization, the number and type of drugs taken vary with gender and place of birth.

Africa↗

PubMed2002

Effect of raloxifene on the ovarian circulation in women after menopause.

OBJECTIVE: We sought to determine whether raloxifene effects the ovarian circulation in women after menopause. STUDY DESIGN: The resistance indices of the ovarian blood flow were assessed in 130 women after menopause who were randomly assigned to receive either 60 mg of raloxifene, a continuous combined estrogen-progestin tablet daily, or neither treatment for 24 months. RESULTS: The women who received raloxifene or hormonal replacement therapy had a significant time-related decrease in the resistance index of the ovarian artery blood flow compared to baseline values (resistance index, 0.91) starting after 12 and 18 months of treatment (resistance index, 0.88 and 0.89, respectively; P <.002 and.001, respectively). Whereas significant increases in the resistance index respective to the prestudy values were observed in the nontreated women at 24 months (resistance index, 0.93; P <.0001). The mean (+/-SD) resistance index of the ovarian blood flow at the end of the study (resistance index, 0.89) was significantly lower in the women who were treated with raloxifene than in the women who were treated with hormone replacement therapy (P <.002). No changes in the ovarian dimensions or appearance were noticed during the entire study. CONCLUSION: Daily therapy with raloxifene has significant ovarian vascular-relaxing effect in women after menopause. This potentially important direct vasculoprotective long-term effect of raloxifene on cardiovascular disease deserves further investigation.

Aged↗