Exposure to pesticides as risk factor for non-Hodgkin's lymphoma and hairy cell leukemia: pooled analysis of two Swedish case-control studies

Increased risk for non-Hodgkin's lymphoma (NHL) following exposure to certain pesticides has previously been reported. To further elucidate the importance of phenoxyacetic acids and other pesticides in the etiology of NHL a pooled analysis was performed on two case-control studies, one on NHL and another on hairy cell leukemia (HCL), a rare subtype of NHL. The studies were population based with cases identified from cancer registry and controls from population registry. Data assessment was ascertained by questionnaires supplemented over the telephone by specially trained interviewers. The pooled analysis of NHL and HCL was based on 515 cases and 1141 controls. Increased risks in univariate analysis were found for subjects exposed to herbicides (OR 1.75, CI 95% 1.26-2.42), insecticides (OR 1.43, CI 95% 1.08-1.87), fungicides (OR 3.11, CI 95% 1.56-6.27) and impregnating agents (OR 1.48, CI 95% 1.11-1.96). Among herbicides, significant associations were found for glyphosate (OR 3.04, CI 95% 1.08-8.52) and 4-chloro-2-methyl phenoxyacetic acid (MCPA) (OR 2.62, CI 95% 1.40-4.88). For several categories of pesticides the highest risk was found for exposure during the latest decades before diagnosis. However, in multivariate analyses the only significantly increased risk was for a heterogeneous category of other herbicides than above.     

Optimization of the workup procedure for the analysis of 8-oxo-7,8-dihydro-2'-deoxyguanosine with electrochemical detection

The artifactual generation of the biomarker for oxidative stress, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), during the workup procedure for its analysis is a difficult problem to solve, and the responsible factors are unclear. Here, peroxide removal and other antioxidant procedures during workup were compared using a limited amount of rat liver (50 mg) as starting material, with subsequent hydrolysis of 50 microg of DNA. A cold (0 degrees C) high salt GTC (4 M guanidine thiocyanate) nonphenol DNA extraction method was developed where DNA is quickly isolated. GSH (reduced glutathione) generated artifactual formation of 8-oxodG during the workup procedure, whereas H(2)O(2) removal using catalase, Fe(3+) removal and passivation using desferal, peroxide removal using glutathione peroxidase, ebselen and a peroxidase mimic lowered the 8-oxodG levels, all identifying peroxides as the responsible oxidants. Desferal was more protective when excluding Mg(2+) and Ca(2+) from buffers but was found to disturb the electrochemical detector when repeatedly injected five to six times, even at 100 microM. Addition of the OH(*) scavenger ethanol in all steps at 2% v/v had no protective effect. Zn(2+) was found necessary for efficient DNA hydrolysis using nuclease P(1), which was poor below 37 degrees C. Use of water substitutes was tested but inhibited DNA hydrolysis completely. H(2)(18)O could, however, work for mass spectrometry methods. Long-term (38 days) storage of 0.5% v/v Triton X-100 generated more 8-oxodG than Tween 20 when incubated with free dG. The cold GTC DNA extraction method was used for analysis of freshly isolated human lymphocytes/monocytes from 60 healthy men using catalase and TEMPO as antioxidants, giving a background level of 0.074 +/- 0.027 8-oxodG/10(5) dG (or 16 8-oxodG/10(8) nucleotides or 1943 8-oxodG/nuclei) which is probably the lowest value obtained yet. No increase with age was seen. Oxidation of dG to 8-oxodG during workup was found to fit a mathematically defined curve, and a calculated background level of 0.047 8-oxodG/10(5) dG was obtained. To obtain more reliable results it is recommended that control samples are included during the workup procedure, having an equal amount of cells (or DNA) as the exposed samples.     

Thyroid cancer after X-ray treatment of benign disorders of the cervical spine in adults

While there is very good epidemiological evidence for induction of thyroid cancer by radiation exposure in children, the risk for adults after exposure is still uncertain, especially when concerning relatively small radiation doses. A cohort of 27,415 persons which in 1950 through 1964 had received x-ray treatment for various benign disorders in the locomotor system (such as painful arthrosis and spondylosis) was selected from three hospitals in Northern Sweden. A proportion of this cohort, consisting of 8 ,44 persons (4,075 men and 4,069 women), had received treatment to the cervical spine and thereby received an estimated average dose in the thyroid gland of about 1 Gy. Standard incidence rates (SIR) were calculated by using the Swedish Cancer Register. In the cervical spine cohort, 22 thyroid cancers were found versus 13.77 expected (SIR 1.60, CI 1.00-2.42). The corresponding figures for women were 16 observed cases versus 9.60 expected cases (SIR 1.67: Cl 0.75-2.71). Most thyroid cancers (15 out of 22) were diagnosed > 15 years after the exposure. In the remaining part of the total cohort, i.e. those without cervical spine exposure, no increased risk of thyroid cancer was found (SIR 0.98, CI 0.64-1.38). The study strongly suggests that external radiation exposure of adults at relatively small doses increases the risk of thyroid cancer but also that this increase is very much lower than that reported after exposure in children.     

Evaluation of exhaled nitric oxide in schoolchildren at different exhalation flow rates

Nitric oxide (NO) in exhaled air is believed to reflect allergic inflammation in the airways. Measured levels of exhaled NO vary with the exhaled flow rate, which therefore must be standardized. The aim of this study was to estimate the optimal exhalation flow rate when measuring NO in exhaled air. We studied 15 asthmatic children (8-18 y) with elevated NO levels and 15 age-matched controls and focused on how the quality of the NO curve profile, the discriminatory power, and the reproducibility were influenced by the exhalation flow rate. We used an on-line system for NO measurements at six different exhalation flow rates in the interval of 11-382 mL/s. The fraction of exhaled nitric oxide (FENO) was highly flow-dependent as was expected. Intermediate flow rates yielded a flat and stable NO plateau and were considerably easier to interpret than those obtained at the highest and lowest flow rates. The ratio of FENO between asthmatics and controls was lower at higher flow rates and a considerable overlap in NO values was demonstrated at all flow rates except 50 mL/s. The reproducibility was much lower at more extreme flow rates and was best at 50 mL/s. We conclude that a target exhalation flow rate of approximately 50 mL/s is to be preferred using the single-breath method for on-line NO measurements in schoolchildren.     

Effects of a lipid lowering fibrate and hormone replacement therapy on serum lipids and lipoproteins in overweight postmenopausal women with elevated triglycerides

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death in women after menopause. In essence major risk factors for CVD are similar in women as for men inclusive of serum lipid perturbations. The effects of estrogens and hormone replacement therapy on lipid metabolism is widely discussed and warrant further evaluation especially when combined with other lipid lowering drugs. STUDY DESIGN: Postmenopausal women were studied by an open randomised study during 9 months. Subjects were recruited from outpatient clinics in a rural area of Sweden. Major inclusive criteria comprised body mass index (BMI) >28, serum triglycerides >1.5 mmol/l. Participants were at least 12 months postmenopause with a concomitant serum Follicle Stimulating Hormone (FSH) above 28 IU/l. After inclusion in the study patients were instructed to adhere to a low-fat and caloric diet for 3 months and after this period randomised into two groups of intervention; a lipidlowering fibrate (LLF) group and one hormone replacement therapy group (HRT). The LLF group was given gemfibrozil 600 mg orally twice daily and HRT group received 2 mg oestradiol in combination with 1 mg norethisterone acetate as a continuous combined therapy once daily. After 3 months, the LLF group added the HRT regimen and patients in the HRT group added gemfibrozil. Hence, all participants received the regimens combined for the last 6 months of the study. RESULTS: Serum s-cholesterol was markedly decreased in both groups during the first 3 months of single treatment (P<0.0001). This decrease reflected a reduction especially of calculated low density lipoprotein (LDL) s-cholesterol (P<0.001). High density lipoprotein (HDL) s-cholesterol was reduced in the HRT group (P<0.005) but increased (P<0.004) in the LLF group. Triglycerides were also decreased by both treatments but more marked in the LLF group (P<0.0001) than in the HRT group (P<0.02). After 9 months the reduction remained in both groups but no additive effects were encountered in any of the groups. CONCLUSION: The effects by gemfibrozil on s-cholesterol and triglycerides levels seem to be superior to continuous combined HRT in overweight women with elevated triglycerides. The combination of the two drugs did not seem to offer any additional benefit concerning the routine serum lipid or lipoprotein profile.     

Descriptive study and pharmacotherapeutic intervention in patients with epilepsy or Parkinson's disease at nursing homes in southern Sweden

OBJECTIVES: To describe the drug use in epilepsy and Parkinson's patients living in nursing homes and to evaluate the impact of multi-speciality team intervention on health-related quality of life, activities of daily living (ADL) and confusion state. METHODS: Nursing home residents with epilepsy or Parkinson's disease in the county of Sk?ne in Sweden were identified. From 119 nursing homes, 262 patients were identified. After obtaining informed consent, 157 patients from 48 nursing homes were included. Of these patients 74 were diagnosed with epilepsy and 84 with Parkinson's disease (one patient had both diagnoses). The average age of the epilepsy patients was 79 years and of the Parkinson's patients 81 years. Pharmacists documented the patients' drug use and any drug-related problems after communication with nursing-home residents, their contact persons at the nursing home and the residents' physicians. A multi-speciality group consisting of pharmacists, a primary care physician, a neurologist, a neuro-psychiatrist and a clinical pharmacologist evaluated the patients' medication and, when appropriate, suggested changes. Lists of each resident's medications were collected together with information about drug-related problems. The use of drugs deemed inappropriate for geriatric nursing-home residents according to Beer's criteria was documented. Health-related quality of life was evaluated using a generic health-related quality of life instrument, SF-36. Confusion state was measured using the Behaviour Pathology in Alzheimer's Disease Rating Scale (Behave-AD), and ability to perform ADL was assessed using the Schwab and England capacity for daily living scale. All measurements were repeated after approximately 6 months. During that period, for the group randomised to active intervention, the physicians involved in the care of the patients had received the recommendations for changes in drug treatment from the multi-speciality group. RESULTS: Epilepsy patients at nursing homes used on average 8.0 drugs for continuous use whereas Parkinson's patients used 8.6 drugs. According to Beer's criteria about 40% of both patient groups used drugs that are classified as inappropriate to geriatric nursing-home patients. Dopamine receptor-blocking psychotropic drugs were used by 29% of the Parkinson's patients. Indication for a patient's total drug treatment was not documented for 50% of epilepsy and 40% of Parkinson's patients. There were no significant differences between the active and control groups in changes in SF-36, Behave-AD or ADL for epilepsy patients. For Parkinson's patients there was a significant decrease in ADL for the active group, whereas there were no differences in SF-36 or Behave-AD. CONCLUSION: Nursing-home residents with epilepsy or Parkinson's disease use many drugs and often drugs that are classified as inappropriate. A simple problem-oriented questionnaire may be helpful in identifying specific drug-related problems in geriatric patients with common neurological diseases. Methods on how to improve the pharmacotherapy of these patients still have to be developed.     

Simple method based on fluorescent detection for the determination of 4-hydroxycyclophosphamide in plasma

Cyclophosphamide is a prodrug used both as a single drug and in combination chemotherapy. Cyclophosphamide is converted to its active metabolite (4-hydroxycyclophosphamide) by the cytochrome P450 enzymes. A liquid chromatography method including liquid-liquid extraction and protein precipitation in one step was developed to measure 4-hydroxycyclophosphamide in plasma. The 4-hydroxycyclophosphamide was stabilized and converted to a fluorescent dansylhydrazone derivative, which was chromatographed on a reverse-phase column and detected using a spectrofluorometric detector at excitation of 350 nm and emission of 550 nm. The limit of quantitation was 60 ng/mL and the between-day accuracy and precision were less than 9%. The method was applied to the analysis of plasma from patients who had received an intravenous infusion of 1 g/m(2) cyclophosphamide.     

Quantitative evaluation of the murine B16 melanoma tumor model after gene marking with an EGFP/Neo expressing retroviral vector

Reliable evaluation of tumor growth in animal models depends upon accurate identification of all malignant cells in affected organs. An ideal tumor cell label is non-toxic, labels the cells in a population uniformly and does not affect their biological behavior. A good candidate for such a cell label is enhanced green fluorescence protein (EGFP). However, the stability of EGFP expression and the characteristics of EGFP-marked tumors cells in vivo have not yet been elucidated in detail. We here report that a B16 murine melanoma subline stably transduced with an EGFP/Neo encoding retroviral vector display the same growth patterns in vitro and in vivo as the parental cell line. Furthermore, the transduced cells were found to maintain the level of EGFP expression in vivo for at least 15 days. Thus, B16 malignant melanoma cells stably transduced with the gene for EGFP seem well suited for studies on tumor growth in mouse models.     

Adjustment of Incidence Rates after an Estimate of Completeness and Accuracy in Registration of Acute Leukemias in a Swedish Population

Earlier studies have revealed undernotification of hematological malignancies in Swedish and other Cancer Registries. We present epidemiological data on AML, ALL and unspecified AL in adults diagnosed 1987-1992 in a well-defined population. Blast crises of CML were excluded. The Swedish Cancer Registry and Cause of Death Registry were compared and patient records reviewed for validation. When available, listings of pathology bone marrow reports and inpatient discharge diagnoses were utilized for casefinding. 260 cases of acute leukemias could be verified in a population of 663,135 adults, corresponding to a yearly incidence of 6.5/100,000. The median age of the patients was 69.2 years. 214 cases were AML, 38 ALL and eight unspecified AL. Undernotification in the Cancer Registry was found to be 15.4%, greater for AML and unspecified AL than for ALL. In addition the coding was not uniform, resulting in an incidence rate in adults of 5.3/100,000 for the Cancer Registry which is 18.5% lower than that of our study. A significant survival advantage was seen for notified patients. Combination of the Cancer Registry and Cause of Death Registry gave acceptable coverage, omitting only four patients. As the incidence of acute leukemias in our study is comparatively high, we hypothesize that underestimation of incidence and overestimation of survival are general problems for cancer registries.     

Increased Level of Soluble HLA Class I Antigens in Systemic Lupus Erythematosus: Correlation with Anti-DNA Antibodies and Leukopenia

The concentration of soluble HLA class I (sHLA-I) was measured by ELISA in serum samples from 30 well-characterised SLE patients at high and low disease activity states and from 100 healthy controls. HLA-A allotypes in the patients were analysed by a PCR-based typing technique. A higher level of sHLA-I was found in SLE patient sera both at high and low disease activity than in controls (P< 0.001). The sHLA-I level was further increased during active disease (P< 0.01). Concentrations of sHLA-I correlated with anti-dsDNA antibodies at high disease activity, but not with disease activity as analysed by a modified SLEDAI. Numbers of leukocytes and lymphocytes, as well as levels of C1q and C3 correlated inversely with sHLA-I concentration. In five serial samples from ten patients the sHLA-I level co-varied with disease activity. Presence of HLA allotype A9 was associated with higher sHLA-I levels in both patients (P< 0.001) and controls (P< 0.001). We conclude that the increased sHLA-I concentration in SLE patients was related to several laboratory parameters reflecting disease activity suggesting that sHLA-I molecules are connected with the disease process. Increased sHLA-I level due to HLA-A allotype was not a disease susceptibility factor for SLE.