Pesticides as a potential independent childhood leukemia risk factor and as a potential confounder for electromagnetic fields exposure.

BACKGROUND: Both pesticides and high magnetic fields are suspected to be childhood leukemia risk factors. Pesticides are utilized at commercial plant nurseries, which sometimes occupy the areas underneath high-voltage powerlines. OBJECTIVES: To evaluate whether potential pesticide exposures (intended use, chemical class, active ingredient) utilized at plant nurseries act as an independent childhood leukemia risk factor or as a confounder for proximity to, or magnetic fields exposure from, high-voltage powerlines. METHODS: We conducted a state-wide records-based case-control study for California with 5788 childhood leukemia cases and 5788 controls that examined specific pesticide use, magnetic field exposures and distances to both powerlines and plant nurseries. Exposure assessment incorporated geographic information systems, aerial satellite images, and other historical information. RESULTS: Childhood leukemia risk was potentially elevated for several active pesticide ingredients: permethrin (odds ratio (OR) 1.49, 95% confidence interval (CI) (0.83-2.67), chlorpyrifos (OR 1.29, 95% CI 0.89-1.87), dimethoate (OR 1.79, 95% CI 0.85-3.76), mancozeb (OR 1.41, 95% CI 0.85-2.33), oxyfluorfen (OR 1.41, 95% CI 0.75-2.66), oryzalin (OR 1.60, 95% CI 0.97-2.63), and pendimethalin (OR 1.82, 95% CI 0.81-2.25). Rodenticide (OR 1.42, 95% CI 0.78-2.56) and molluscicide (OR 1.22, 95% CI 0.82-1.81) exposure also presented potentially elevated childhood leukemia risks. Childhood leukemia associations with calculated fields or powerline proximity did not materially change after adjusting for pesticide exposure. Childhood leukemia risks with powerline proximity remained similar when pesticide exposures were excluded. DISCUSSION: Pesticide exposure may be an independent childhood leukemia risk factor. Childhood leukemia risks for powerline proximity and magnetic fields exposure were not explained by pesticide exposure.

Commercial outdoor plant nurseries as a confounder for electromagnetic fields and childhood leukemia risk.

BACKGROUND: Close residential proximity to powerlines and high magnetic fields exposure may be associated with elevated childhood leukemia risks as reported by prior studies and pooled analyses. Magnetic fields exposure from high-voltage powerlines is associated with proximity to these powerlines and consequently with any factor varying with distance. Areas underneath powerlines in California may be sites for commercial plant nurseries that can use pesticides, a potential childhood leukemia risk factor. OBJECTIVES: Assess if potential pesticide exposure from commercial plant nurseries is a confounder or interacts with proximity or magnetic fields exposure from high-voltage powerlines to increase childhood leukemia risk. METHODS: A comprehensive childhood leukemia record-based case-control study with 5788 cases and 5788 controls (born and diagnosed in California, 1986-2008) was conducted. Pesticide, powerline, and magnetic field exposure assessment utilized models that incorporated geographical information systems, aerial satellite images, site visits and other historical information. RESULTS: The relationship for calculated fields with childhood leukemia (odds ratio (OR) 1.51, 95% confidence interval (CI) 0.70-3.23) slightly attenuated when controlling for nursery proximity (OR 1.43, 95% CI 0.65-3.16) or restricting analysis to subjects living far (>300 m) from nurseries (OR 1.43, 95% CI 0.79-2.60). A similar association pattern was observed between distance to high-voltage powerlines and childhood leukemia. The association between nursery proximity and childhood leukemia was unchanged or only slightly attenuated when controlling for calculated fields or powerline distance; ORs remained above 2 when excluding subjects with high calculated fields or close powerline proximity (OR 2.16, 95% CI 0.82-5.67 and OR 2.15, 95% CI 0.82-5.64, respectively). The observed relationships were robust to different time periods, reference categories, and cut points. DISCUSSION: Close residential proximity to nurseries is suggested as an independent childhood leukemia risk factor. Our results do not support plant nurseries as an explanation for observed childhood leukemia risks for powerline proximity and magnetic fields exposure, although small numbers of subjects concurrently exposed to high magnetic fields, close powerline proximity and plant nurseries limited our ability to fully assess potential confounding.

The role of dwelling type when estimating the effect of magnetic fields on childhood leukemia in the California Power Line Study (CAPS).

PURPOSE: The type of dwelling where a child lives is an important factor when considering residential exposure to environmental agents. In this paper, we explore its role when estimating the potential effects of magnetic fields (MF) on leukemia using data from the California Power Line Study (CAPS). In this context, dwelling type could be a risk factor, a proxy for other risk factors, a cause of MF exposure, a confounder, an effect-measure modifier, or some combination. METHODS: We obtained information on type of dwelling at birth on over 2,000 subjects. Using multivariable-adjusted logistic regression, we assessed whether dwelling type was a risk factor for childhood leukemia, which covariates and MF exposures were associated with dwelling type, and whether dwelling type was a potential confounder or an effect-measure modifier in the MF-leukemia relationship under the assumption of no-uncontrolled confounding. RESULTS: A majority of children lived in single-family homes or duplexes (70%). Dwelling type was associated with race/ethnicity and socioeconomic status but not with childhood leukemia risk, after other adjustments, and did not alter the MF-leukemia relationship upon adjustment as a potential confounder. Stratification revealed potential effect-measure modification by dwelling type on the multiplicative scale. CONCLUSION: Dwelling type does not appear to play a significant role in the MF-leukemia relationship in the CAPS dataset as a leukemia risk factor or confounder. Future research should explore the role of dwelling as an effect-measure modifier of the MF-leukemia association.

Relationship between distance to overhead power lines and calculated fields in two studies.

There is some evidence that both distance from transmission lines and measured or calculated magnetic fields are associated with childhood leukemia. Because distance is a key component when calculating the magnetic field generated by power lines, distance from lines and calculated fields based on lines tend to be highly correlated. Socioeconomic status (SES) and dwelling type are also associated with magnetic field exposure. We used exposure data from two large studies of childhood leukemia and other cancers, in the US and the UK, to describe a relationship between distance and magnetic fields across the population within 100 meters (m) of power lines as a whole and evaluate potential modifiers such as SES and type of dwelling. There were 387 subjects living within 100 m of an overhead power line. There was no significant difference in mean calculated fields or distance to 200+ kV lines within 100 m by study. Within the range where the power-line field is expected to be significant compared to other sources, which we take as 100 m, distance to high-voltage lines predicted magnetic field (MF) variation in both studies better than other functions of distance tested in both linear and logistic regression. There were no differences between high and low SES or dwelling types (single-family home versus other). In conclusion, we found that calculated fields do appear to diminish linearly with increasing distance from overhead power lines, up to 100 m, particularly those 200+ kV and above. These results are stronger in the UK study. Within 100 m, distance to high-voltage lines continues to be highly correlated with calculated MFs and each can be a proxy for the other.

Changes over time in the reported risk for childhood leukaemia and magnetic fields.

There have been many studies from 1979 to the present reporting raised risks for childhood leukaemia with exposure to power-frequency magnetic fields. There are also suggestions that the reported risk has been decreasing. We examine trends in the risk over time from all available studies. For 41 studies, we combine reported risks using inverse-variance weighting, drawing risk estimates from previous pooled analyses where possible for greater consistency. We examine the cumulative risk for studies published up to each successive calendar year for all studies and for various subsets, and test for a trend over the period. The cumulative relative risk has indeed declined, for our most rigorous analysis from a maximum 2.44 in 1997 to 1.58 in 2017, but not statistically significantly when tested as a linear trend. We find suggestions of higher risks in studies looking at higher exposures and in studies with better quality exposure assessment. We conclude that there is a decline in reported risk from the mid 1990s to now, which is unlikely to be solely explained by improving study quality but may be due to chance, and an elevated risk remains.

Residential mobility and childhood leukemia.

AIMS: Studies of environmental exposures and childhood leukemia studies do not usually account for residential mobility. Yet, in addition to being a potential risk factor, mobility can induce selection bias, confounding, or measurement error in such studies. Using data collected for California Powerline Study (CAPS), we attempt to disentangle the effect of mobility. METHODS: We analyzed data from a population-based case-control study of childhood leukemia using cases who were born in California and diagnosed between 1988 and 2008 and birth certificate controls. We used stratified logistic regression, case-only analysis, and propensity-score adjustments to assess predictors of residential mobility between birth and diagnosis, and account for potential confounding due to residential mobility. RESULTS: Children who moved tended to be older, lived in housing other than single-family homes, had younger mothers and fewer siblings, and were of lower socioeconomic status. Odds ratios for leukemia among non-movers living <50 meters (m) from a 200+ kilovolt line (OR: 1.62; 95% CI: 0.72-3.65) and for calculated fields ≥ 0.4 microTesla (OR: 1.71; 95% CI: 0.65-4.52) were slightly higher than previously reported overall results. Adjustments for propensity scores based on all variables predictive of mobility, including dwelling type, increased odds ratios for leukemia to 2.61 (95% CI: 1.76-3.86) for living < 50 m from a 200 + kilovolt line and to 1.98 (1.11-3.52) for calculated fields. Individual or propensity-score adjustments for all variables, except dwelling type, did not materially change the estimates of power line exposures on childhood leukemia. CONCLUSION: The residential mobility of childhood leukemia cases varied by several sociodemographic characteristics, but not by the distance to the nearest power line or calculated magnetic fields. Mobility appears to be an unlikely explanation for the associations observed between power lines exposure and childhood leukemia.

24-h personal monitoring of exposure to Power Frequency Magnetic Fields in adolescents - Results of a National Survey.

OBJECTIVES: The aim of this exposure assessment study was to gain information about the exposure levels of adolescents in Israel to power frequency (50Hz) magnetic fields (MF) through personal monitoring, and to provide reliable data for national policy development. METHODS: 84 adolescents, 6-10th grade students, carried an EMDEX II meter attached to their body for 24h. The meter recorded the MF every 1.5s. The students documented their activities and microenvironments, such as apartment (awake or asleep), school, transportation, open public areas and other indoor environments. RESULTS: The geometric mean (GM) of the daily time weighted average (TWA) of all the participants was 0.059 µT (STD = 1.83). This result is similar to those of personal exposure surveys conducted in the UK (GM 0.042-0.054µT), but lower than levels found in the US (GM 0.089 - 0.134µT). The arithmetic mean was 0.073µT, 23% higher than the GM. Fields were lowest at school (GM 0.033µT), and average outdoor exposures were higher than indoor ones. 3.6% of the participants were exposed to daily TWA above 0.2µT. The typical time spent above 0.2µT ranged from few minutes to few hours. The time spent above 0.4µT and 1µT were much shorter, around 1-15min and from few seconds to 2min, respectively. Momentary peaks ever recorded were in the range of 0.35-23.6µT CONCLUSIONS: Exposure of adolescents in Israel is similar to data reported in other countries, being below 0.1µT for the vast majority, with very few average exposures above 0.2µT. Analysis of the different microenvironments allows for a cost-effective and equitable policy development.

Occupational exposures to radiofrequency fields: results of an Israeli national survey.

Relatively high exposures to radiofrequency (RF) fields can occur in the broadcast, medical, and communications industries, as well in occupations that use RF emitting equipment (e.g. law enforcement). Information on exposure to workers employed in these industries and occupations is limited. We present results of an Israeli National Survey of occupational RF field levels at frequencies between ~100 kHz and 40 GHz, representing Industrial Heating, Communications, Radar, Research, and Medicine. Almost 4300 measurements from 900 sources across 25 occupations were recorded and categorised as 'routine', 'incidental', or 'unintended'. The occupation-specific geometric means (GMs) of the percentage of the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) for each of the three exposure scenarios are presented together with the geometric standard deviation (GSD). Additionally, we present estimates of occupation-specific annual personal exposures and collective exposures. The vast majority of the GM of routine exposures ranged from a fraction to less than 1% of ACGIH TLVs, except for Walkie-Talkie (GM 94% of ACGIH), Induction Heating (17%), Plastic Welding (11%), Industrial Heating (6%) and Diathermy (6%). The GM of incidental and unintended exposures exceeded the TLV for one and 14 occupations, respectively. In many cases, the within-occupation GSD was very large, and though the medians remained below TLV, variable fractions of these occupations were projected to exceed the TLV. In rank order, Walkie-Talkie, Plastic Welding, and Induction Heating workers had the highest annual cumulative personal exposure. For cumulative collective exposures within an occupation, Walkie-Talkie dominated with 96.3% of the total, reflecting both large population and high personal exposure. A brief exceedance of the TLV does not automatically translate to hazard as RF exposure limits (issued by various bodies, including ACGIH) include a 10-fold safety factor relative to thermal thresholds and are based on a 6 min averaging period.

Birth weight and other perinatal factors and childhood CNS tumors: a case-control study in California.

AIMS: We conducted a large registry-based study in California to investigate the association of perinatal factors and childhood CNS tumors, with analysis by tumor subtype. METHODS: We linked California cancer and birth registries to obtain information on 3308 cases and 3308 controls matched on age and sex. We examined the association of birth weight, gestational age, birth order, parental ages, maternal conditions during pregnancy, newborn abnormalities and the risk of childhood CNS tumors using conditional logistic regression, with adjustment for potential confounders. RESULTS: The odds ratio (OR) per 1000 g increase in birth weight was 1.11 (95% CI: 0.99-1.24) for total childhood CNS tumors, 1.17 (95% CI: 0.97-1.42) for astrocytoma and 1.28 (95% CI: 0.90-1.83) for medulloblastoma. Compared to average-for-gestational age, large-for-gestational age infants were at increased risk of glioma (OR=1.86, 95% CI: 0.99-3.48), while small-for-gestational age infants were at increased risk of ependimoma (OR=2.64, 95% CI: 1.10-6.30). Increased risk of childhood CNS tumors was observed for 5-year increase in maternal and paternal ages (OR=1.06, 95% CI: 1.00-1.12 and 1.05, 95% CI: 1.00-1.10 respectively). Increased risk of astrocytoma was detected for 5-year increase in paternal age (OR=1.08; 95% CI: 1.00-1.16) and increased risk of glioma for maternal age ≥ 35 years old (OR=1.87; 95% CI: 1.00-3.52). Maternal genital herpes during pregnancy was associated with a pronounced increase in risk of total CNS tumors (OR=2.74; 95% CI: 1.16-6.51). Other (non-sexually transmitted) infections during pregnancy were associated with decreased risk of total CNS tumors (OR=0.28, 95% CI: 0.09-0.85). Maternal blood/immune disorders during pregnancy were linked to increased risk of CNS tumors (OR=2.28, 95% CI: 1.08-4.83) and medulloblastoma (OR=7.13, 95% CI: 0.82-61.03). Newborn CNS abnormalities were also associated with high risk of childhood CNS tumors (OR=4.08, 95% CI: 1.13-14.76). CONCLUSIONS: Our results suggest that maternal genital herpes, blood and immunological disorders during pregnancy and newborn CNS abnormalities were associated with increased risk of CNS tumors. Maternal infections during pregnancy were associated with decreased risk of CNS tumors. Advanced maternal and paternal ages may be associated with a slightly increased risk of CNS tumors. Factors associated with CNS tumor subtypes varied by subtype, an indicator of different etiology for different subtypes.

Extremely low-frequency magnetic fields and survival from childhood acute lymphoblastic leukemia: an international follow-up study.

A previous US study reported poorer survival in children with acute lymphoblastic leukemia (ALL) exposed to extremely low-frequency magnetic fields (ELF-MF) above 0.3 µT, but based on small numbers. Data from 3073 cases of childhood ALL were pooled from prospective studies conducted in Canada, Denmark, Germany, Japan, UK and US to determine death or relapse up to 10 years from diagnosis. Adjusting for known prognostic factors, we calculated hazard ratios (HRs) and 95% confidence intervals (CI) for overall survival and event-free survival for ELF-MF exposure categories and by 0.1 µT increases. The HRs by 0.1 µT increases were 1.00 (CI, 0.93-1.07) for event-free survival analysis and 1.04 (CI, 0.97-1.11) for overall survival. ALL cases exposed to >0.3 µT did not have a poorer event-free survival (HR=0.76; CI, 0.44-1.33) or overall survival (HR=0.96; CI, 0.49-1.89). HRs varied little by subtype of ALL. In conclusion, ELF-MF exposure has no impact on the survival probability or risk of relapse in children with ALL.

Could the geomagnetic field be an effect modifier for studies of power-frequency magnetic fields and childhood leukaemia?

Epidemiological studies find an association between power-frequency magnetic fields and childhood leukaemia. One candidate mechanism for a causal link is effects of magnetic fields on biological reactions involving free radicals. This mechanism predicts effects from variations in static, as well as alternating, magnetic fields, and therefore different consequences at different locations on the earth's surface due to variations in geomagnetic field. Testing this directly is problematic. Instead, we investigate whether geomagnetic field appears to be an effect modifier in studies of alternating magnetic fields. We find some, but rather limited and not statistically significant, evidence for this, and discuss the implications.

Birth weight and other perinatal characteristics and childhood leukemia in California.

AIMS: We conducted a large registry-based study in California to investigate the association of perinatal factors and childhood leukemia with analysis of two major subtypes, acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML). METHODS: We linked California cancer and birth registries to obtain information on 5788 cases and 5788 controls matched on age and sex (1:1). We examined the association of birth weight, gestational age, birth and pregnancy order, parental ages, and specific conditions during pregnancy and risk of total leukemia, ALL and AML using conditional logistic regression, with adjustment for potential confounders. RESULTS: The odds ratio (OR) per 1000 g increase in birth weight was 1.11 for both total leukemia and ALL. The OR were highest for babies weighing ≥ 4500 g with reference < 2500 g: 1.59 (95% CI: 1.05-2.40) and 1.70 (95% CI: 1.08-2.68) for total leukemia and ALL, respectively. For AML, increase in risk was also observed but the estimate was imprecise due to small numbers. Compared to average-for-gestational age (AGA), large-for-gestational age (LGA) babies were at slightly increased risk of total childhood leukemia (OR = 1.10) and both ALL and AML (OR = 1.07 and OR = 1.13, respectively) but estimates were imprecise. Being small-for-gestational age (SGA) was associated with reduced risk of childhood leukemia (OR = 0.81, 95% CI: 0.67-0.97) and ALL (OR = 0.77, 95% CI: 0.63-0.94), but not AML. Being first-born was associated with decreased risk of AML only (OR = 0.70; 95% CI: 0.53-0.93). Compared to children with paternal age <25 years, children with paternal age between 35 and 45 years were at increased risk of total childhood leukemia (OR = 1.12; 95% CI: 1.04-1.40) and ALL (OR = 1.23; 95% CI: 1.04-1.47). None of conditions during pregnancy examined or maternal age were associated with increased risk of childhood leukemia or its subtypes. CONCLUSIONS: Our results suggest that high birth weight and LGA were associated with increased risk and SGA with decreased risk of total childhood leukemia and ALL, being first-born was associated with decreased risk of AML, and advanced paternal age was associated with increased risk of ALL. These findings suggest that associations of childhood leukemia and perinatal factors depend highly on subtype of leukemia.

[Congenital polycystic renal disease with concomitant liver fibrosis].

The author presents a case of hereditary disease with polycystic kidneys and hepatic fibrosis complicated by portal hypertension.

Pooled analysis of recent studies on magnetic fields and childhood leukaemia.

BACKGROUND: Previous pooled analyses have reported an association between magnetic fields and childhood leukaemia. We present a pooled analysis based on primary data from studies on residential magnetic fields and childhood leukaemia published after 2000. METHODS: Seven studies with a total of 10,865 cases and 12,853 controls were included. The main analysis focused on 24-h magnetic field measurements or calculated fields in residences. RESULTS: In the combined results, risk increased with increase in exposure, but the estimates were imprecise. The odds ratios for exposure categories of 0.1-0.2 µT, 0.2-0.3 µT and ≥0.3 µT, compared with <0.1 µT, were 1.07 (95% CI 0.81-1.41), 1.16 (0.69-1.93) and 1.44 (0.88-2.36), respectively. Without the most influential study from Brazil, the odds ratios increased somewhat. An increasing trend was also suggested by a nonparametric analysis conducted using a generalised additive model. CONCLUSIONS: Our results are in line with previous pooled analyses showing an association between magnetic fields and childhood leukaemia. Overall, the association is weaker in the most recently conducted studies, but these studies are small and lack methodological improvements needed to resolve the apparent association. We conclude that recent studies on magnetic fields and childhood leukaemia do not alter the previous assessment that magnetic fields are possibly carcinogenic.

Future needs of occupational epidemiology of extremely low frequency electric and magnetic fields: review and recommendations.

The occupational epidemiological literature on extremely low frequency electric and magnetic fields (EMF) and health encompasses a large number of studies of varying design and quality that have addressed many health outcomes, including various cancers, cardiovascular disease, depression and suicide, and neurodegenerative diseases, such as Alzheimer disease and amyotrophic lateral sclerosis (ALS). At a 2006 workshop we reviewed studies of occupational EMF exposure with an emphasis on methodological weaknesses, and proposed analytical ways to address some of these. We also developed research priorities that we hope will address remaining uncertainties. Broadly speaking, extensive epidemiological research conducted during the past 20 years on occupational EMF exposure does not indicate strong or consistent associations with cancer or any other health outcomes. Inconsistent results for many of the outcomes may be attributable to numerous shortcomings in the studies, most notably in exposure assessment. There is, however, no obvious correlation between exposure assessment quality and observed associations. Nevertheless, for future research, the highest priorities emerge in both the areas of exposure assessment and investigation of ALS. To better assess exposure, we call for the development of a more complete job-exposure matrix that combines job title, work environment and task, and an index of exposure to electric fields, magnetic fields, spark discharge, contact current, and other chemical and physical agents. For ALS, we propose an international collaborative study capable of illuminating a reported association with electrical occupations by disentangling the potential roles of electric shocks, magnetic fields and bias. Such a study will potentially lead to evidence-based measures to protect public health.

Exposure assessment and other challenges in non-ionizing radiation studies of childhood leukaemia.

Studies of electromagnetic fields (EMF) and the development of childhood leukaemia face unique difficulties. EMF are imperceptible, ubiquitous, have multiple sources, and can vary greatly over time and distances. Childhood leukaemia and high average exposures to magnetic fields are both quite rare. Thus, a major challenge in EMF epidemiology is the small number of highly exposed cases and the necessity for retrospective assessment of exposure. Only studies designed to minimize bias while maximizing our ability to detect an association, should one exist, would have a potential to contribute to our understanding. New approaches are needed; the most promising in the extremely low-frequency range involves a study of a highly exposed cohort of children who have lived in apartments next to built-in transformers or electrical equipment rooms. Another promising avenue is an investigation of possible joint effects of environmental exposures and genetic co-factors. An exposure assessment methodology for residential radiofrequency fields is still in its infancy. Rapid changes in technology and exponential increases in its use make exposure assessment more difficult and urgent.

Mortality from Alzheimer's, motor neuron and Parkinson's disease in relation to magnetic field exposure: findings from the study of UK electricity generation and transmission workers, 1973-2004.

BACKGROUND: There are a number of reports linking magnetic field exposure to increased risks of Alzheimer's disease and motor neuron disease. METHODS: The mortality experienced by a cohort of 83 997 employees of the former Central Electricity Generating Board of England and Wales was investigated for the period 1973-2004. All employees were employed for at least six months with some employment in the period 1973-82. Computerised work histories were available for 79 972 study subjects for the period 1971-93. Information on job and facility (location) were used to estimate exposures to magnetic fields. Two analytical approaches were used to evaluate risks, indirect standardisation (n = 83 997) and Poisson regression (n = 79 972). RESULTS: Based on serial mortality rates for England and Wales, deaths from Alzheimer's disease and motor neuron disease were unexceptional. There was an excess of deaths from Parkinson's disease of borderline significance. No statistically significant trends were shown for risks of any of these diseases to increase with lifetime cumulative exposure to magnetic fields (RR per 10 µT-y: Alzheimer's disease 1.10 (95% CI 0.90 to 1.33); motor neuron disease 1.06 (95% CI 0.86 to 1.32); Parkinson's disease 0.88 (95% CI 0.74 to 1.05)) CONCLUSIONS: There is no convincing evidence that UK electricity generation and transmission workers have suffered increased risks from neurodegenerative diseases as a consequence of exposure to magnetic fields.

[Osteogenon in therapy of distal radial bone fractures in patients with secondary osteoporosis].

AIM: To assess efficacy of osteogenon in consolidation of solitary fractures of distal part of the radial bone (RB) in patients with secondary osteoporosis (SO) due to rheumatoid arthritis (RA) and chronic renal failure (CRF). MATERIAL AND METHODS: The study group consisted of 7 patients with documented RA and 8 patients with CRF caused by chronic glomerulonephritis or chronic pyelonephritis in the predialysis period. The control group comprised 13 patients (6 and 7 patients, respectively). The patients were matched by clinico-demographic and therapy characteristics. Patients of the study group received osteogen from the fracture diagnosis to its consolidation. RESULTS: Osteogenon has an analgetic effect, improves well being, raises physical activity, reduces duration of fracture consolidation in patients with SO.

Magnetic field exposure and long-term survival among children with leukaemia.

We examined the association between magnetic field (MF) exposure and survival among children with acute lymphoblastic leukaemia (ALL) treated at 51 Pediatric Oncology Group centres between 1996 and 2001. Of 1672 potentially eligible children under treatment, 482 (29%) participated and personal 24-h MF measurements were obtained from 412 participants. A total of 386 children with ALL and 361 with B-precursor ALL were included in the analysis of event-free survival (time from diagnosis to first treatment failure, relapse, secondary malignancy, or death) and overall survival. After adjustment for risk group and socioeconomic status, the event-free survival hazard ratio (HR) for children with measurements >/=0.3 muT was 1.9 (95% confidence interval (CI) 0.8, 4.9), compared to <0.1 muT. For survival, elevated HRs were found for children exposed to >/=0.3 muT (multivariate HR=4.5, 95% CI 1.5-13.8) but based on only four deaths among 19 children. While risk was increased among children with exposures above 0.3 muT, the small numbers limited inferences for this finding.

[Microbiological aspects of identification of patients with drug-resistant tuberculosis]. / Mikrobiologicheskie aspekty vyiavleniia bol'nykh tuberkulezom s lekarstvennoi ustoichivost'iu.

This review discusses controversial issues, such as definitions of drug resistance, the conditions laboratory drug-susceptibility testing in all new patients is justified, and the requirements for the optimum turnaround time of laboratory reports. It also analyses the advantages and disadvantages of different methods for drug susceptibility testing, including those based on cultivation in the solid and liquid media, as well as molecular phenotypic and genotypic methods. While molecular genotypic methods represent the most promising direction for future development, their application in the clinical laboratory setting today is limited to the initial preliminary screening for rifampicin resistance as a marker for possible MDR and as an indicator for the need for subsequent testing with other drugs. The direct susceptibility test in the solid media (at least that with rifampicin and isoniazid) represents the most affordable method that allows timely adjustment in the treatment regimen if drug resistance is detected. The total turnaround time can be as short as three weeks for 85-90% of smear-positive specimens when the agar plate technique is used for a direct test. Introduction of a liquid media system is the next step to achieving the expected results in all patients.