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1.  Risk of lymphoma subtypes after solid organ transplantation in the United States 
British Journal of Cancer  2013;109(1):280-288.
Background:
Solid organ transplant recipients have high risk of lymphomas, including non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL). A gap in our understanding of post-transplant lymphomas involves the spectrum and associated risks of their many histologic subtypes.
Methods:
We linked nationwide data on solid organ transplants from the US Scientific Registry of Transplant Recipients (1987–2008) to 14 state and regional cancer registries, yielding 791 281 person-years of follow-up for 19 distinct NHL subtypes and HL. We calculated standardised incidence ratios (SIRs) and used Poisson regression to compare SIRs by recipient age, transplanted organ, and time since transplantation.
Results:
The risk varied widely across subtypes, with strong elevations (SIRs 10–100) for hepatosplenic T-cell lymphoma, Burkitt's lymphoma, NK/T-cell lymphoma, diffuse large B-cell lymphoma, and anaplastic large-cell lymphoma (both systemic and primary cutaneous forms). Moderate elevations (SIRs 2–4) were observed for HL and lymphoplasmacytic, peripheral T-cell, and marginal zone lymphomas, but SIRs for indolent lymphoma subtypes were not elevated. Generally, SIRs were highest for younger recipients (<20 years) and those receiving organs other than kidneys.
Conclusion:
Transplant recipients experience markedly elevated risk of a distinct spectrum of lymphoma subtypes. These findings support the aetiologic relevance of immunosuppression for certain subtypes and underscore the importance of detailed haematopathologic workup for transplant recipients with suspected lymphoma.
doi:10.1038/bjc.2013.294
PMCID: PMC3708563  PMID: 23756857
non-Hodgkin's lymphoma; Hodgkin's lymphoma; transplantation; immunosuppression; Burkitt's lymphoma; T-cell lymphoma
2.  Polymorphic MLH1 and risk of cancer after methylating chemotherapy for Hodgkin lymphoma 
Journal of medical genetics  2007;45(3):142-146.
Background and objective
Methylating agents are effective chemotherapy agents for Hodgkin lymphoma, but are associated with the development of second primary cancers. Cytotoxicity of methylating agents is mediated primarily by the DNA mismatch repair (MMR) system. Loss of MLH1, a major component of DNA MMR, results in tolerance to the cytotoxic effects of methylating agents and persistence of mutagenised cells at high risk of malignant transformation. We hypothesised that a common substitution in the basal promoter of MLH1 (position −93, rs1800734) modifies the risk of cancer after methylating chemotherapy.
Methods
133 patients who developed cancer following chemotherapy and/or radiotherapy (n=133), 420 patients diagnosed with de novo myeloid leukaemia, 242 patients diagnosed with primary Hodgkin lymphoma, and 1177 healthy controls were genotyped for the MLH1 −93 polymorphism by allelic discrimination polymerase chain reaction (PCR) and restriction fragment length polymorphism assay. Odds ratios and 95% confidence intervals for cancer risk by MLH1 −93 polymorphism status, and stratified by previous exposure to methylating chemotherapy, were calculated using unconditional logistic regression.
Results
Carrier frequency of the MLH1 −93 variant was higher in patients who developed therapy related acute myeloid leukaemia (t-AML) (75.0%, n=12) or breast cancer (53.3%. n=15) after methylating chemotherapy for Hodgkin lymphoma compared to patients without previous methylating exposure (t-AML, 30.4%, n=69; breast cancer patients, 27.2%, n=22). The MLH1 −93 variant allele was also over-represented in t-AML cases when compared to de novo AML cases (36.9%, n=420) and healthy controls (36.3%, n=952), and was associated with a significantly increased risk of developing t-AML (odds ratio 5.31, 95% confidence interval 1.40 to 20.15), but only in patients previously treated with a methylating agent.
Conclusions
These data support the hypothesis that the common polymorphism at position −93 in the core promoter of MLH1 defines a risk allele for the development of cancer after methylating chemotherapy for Hodgkin lymphoma. However, replication of this finding in larger studies is suggested.
doi:10.1136/jmg.2007.053850
PMCID: PMC4022773  PMID: 17959715
3.  Risk of treatment-related esophageal cancer among breast cancer survivors 
Annals of Oncology  2012;23(12):3081-3091.
Background
Radiotherapy for breast cancer may expose the esophagus to ionizing radiation, but no study has evaluated esophageal cancer risk after breast cancer associated with radiation dose or systemic therapy use.
Design
Nested case–control study of esophageal cancer among 289 748 ≥5-year survivors of female breast cancer from five population-based cancer registries (252 cases, 488 individually matched controls), with individualized radiation dosimetry and information abstracted from medical records.
Results
The largest contributors to esophageal radiation exposure were supraclavicular and internal mammary chain treatments. Esophageal cancer risk increased with increasing radiation dose to the esophageal tumor location (Ptrend < 0.001), with doses of ≥35 Gy associated with an odds ratio (OR) of 8.3 [95% confidence interval (CI) 2.7–28]. Patients with hormonal therapy ≤5 years preceding esophageal cancer diagnosis had lower risk (OR = 0.4, 95% CI 0.2–0.8). Based on few cases, alkylating agent chemotherapy did not appear to affect risk. Our data were consistent with a multiplicative effect of radiation and other esophageal cancer risk factors (e.g. smoking).
Conclusions
Esophageal cancer is a radiation dose-related complication of radiotherapy for breast cancer, but absolute risk is low. At higher esophageal doses, the risk warrants consideration in radiotherapy risk assessment and long-term follow-up.
doi:10.1093/annonc/mds144
PMCID: PMC3501231  PMID: 22745217
breast cancer; esophageal cancer; radiotherapy; second cancer
4.  FDG-PET metabolic response predicts outcomes in anal cancer managed with chemoradiotherapy 
British Journal of Cancer  2011;105(4):498-504.
Background:
The aim was to investigate the correlation between 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) metabolic response to chemoradiotherapy and clinical outcomes in squamous cell carcinoma (SCC) of the anus.
Methods:
A total of 48 patients with biopsy-proven anal SCC underwent FDG-PET scans at baseline and post chemoradiotherapy (54 Gy, concurrent 5-FU/mitomycin). Kaplan–Meier analysis was used to determine survival outcomes according to FDG-PET metabolic response.
Results:
In all, 79% patients (n=38) had a complete metabolic response (CMR) at all sites of disease, 15% (n=7) had a CMR in regional nodes but only partial response in the primary tumour (overall partial metabolic response (PMR)) and 6% (n=3) had progressive distant disease despite CMR locoregionally (overall no response (NR)). The 2-year progression-free survival (PFS) was 95% for patients with a CMR, 71% for PMR and 0% for NR (P<0.0001). The 5-year overall survival (OS) was 88% in CMR, 69% in PMR and 0% in NR (P<0.0001). Cox proportional hazards regression analyses for PFS and OS found significant associations for incomplete (PMR+NR) vs complete FDG-PET response to treatment only, (HR 4.1 (95% CI: 1.5–11.5, P=0.013) and 6.7 (95% CI: 2.1–21.6, P=0.002), respectively).
Conclusion:
FDG-PET metabolic response to chemoradiotherapy in anal cancer is significantly associated with PFS and OS, and in this cohort incomplete FDG-PET response was a stronger predictor than T or N stage.
doi:10.1038/bjc.2011.274
PMCID: PMC3170972  PMID: 21792197
anal cancer; chemoradiotherapy; metabolic response; FDG-PET
6.  Polychlorinated biphenyl serum concentrations, lifestyle and time-to-pregnancy 
BACKGROUND
Consumption of fish contaminated with polychlorinated biphenyls (PCBs) and prenatal PCB serum concentrations have been associated with a longer time-to-pregnancy (TTP). However, the relationship between preconception serum PCBs concentrations and TTP has not been previously studied.
METHODS
Eighty-three women (contributing 442 menstrual cycles) planning pregnancies completed daily diaries regarding menstruation, intercourse, home pregnancy test results, and reported use of alcohol and cigarettes. TTP denoted the number of observed menstrual cycles required for pregnancy. Preconception blood specimens underwent toxicologic analysis for 76 PCB congeners via gas chromatography with electron capture; serum lipids were quantified with enzymatic methods. A priori, PCB congeners were summed into a total and three groupings—estrogenic, anti-estrogenic and other—and entered into discrete analogs of Cox models with time-varying covariates to estimate fecundability odds ratios (FOR) and corresponding 95% confidence intervals (CIs).
RESULTS
Estrogenic and anti-estrogenic PCB concentrations (ng/g serum) conferred reduced FORs in fully adjusted models (0.32; 95% CI 0.03, 3.90 and 0.01: 95% CI < 0.00, 1.99, respectively). Reduced FORs (0.96) were observed for alcohol consumption standardized to a 28-day menstrual cycle in the same adjusted model (FOR = 0.96; 95% CI 0.93, 1.00).
CONCLUSIONS
These data suggest that environmental exposures including those amenable to change, such as alcohol consumption, may impact female fecundity. The findings are sensitive to model specification and PCB groupings, underscoring the need to further assess the impact of chemical mixtures on sensitive reproductive outcomes, such as TTP, especially in the context of lifestyle factors which are amenable to change, thereby improving reproductive health.
doi:10.1093/humrep/den373
PMCID: PMC2628447  PMID: 18940895
time-to-pregnancy; polychlorinated biphenyls; fecundity; lifestyle; environment
7.  Risk for contralateral breast cancer among carriers of the CHEK2*1100delC mutation in the WECARE Study 
British Journal of Cancer  2008;98(4):728-733.
The protein encoded by the CHEK2 gene is involved in cellular repair of DNA damage. The truncating mutation, CHEK2*1100delC, seems to increase the risk for breast cancer. We investigated whether the CHEK2*1100delC mutation carrier status increases the risk for asynchronous contralateral breast cancer (CBC) and whether it interacts with radiation therapy (RT) or chemotherapy in regard to CBC risk. The germline mutation frequency was assessed in 708 women with CBC and 1395 women with unilateral breast cancer (UBC) in the Women's Environment, Cancer and Radiation Epidemiology (WECARE) Study whose first primary breast cancer was diagnosed before age 55 years and during 1985–1999. Seven women with CBC (1.0%) and 10 women with UBC (0.7%) were CHEK2*1100delC variant carriers (rate ratio (RR)=1.8, 95% confidence interval (CI)=0.6–5.4 for CBC vs UBC). Carriers who received RT for their first breast cancer, compared with non-carriers not treated with RT, had an RR of developing CBC of 2.6 (95% CI=0.8–8.7). We found no significant associations between the CHEK2*1100delC mutation and CBC overall or among those treated with RT. However, the sampling variability was such that modest increases in risk could not be excluded. Nonetheless, because this is a rare mutation, it is unlikely to explain a major fraction of CBC in the population.
doi:10.1038/sj.bjc.6604228
PMCID: PMC2259175  PMID: 18253122
asynchronous contralateral breast cancer; CHEK2*1100delC mutation; genes; radiation therapy; chemotherapy
8.  Polychlorinated biphenyl serum concentrations, lifestyle and time-to-pregnancy 
BACKGROUND
Consumption of fish contaminated with polychlorinated biphenyls (PCBs) and prenatal PCB serum concentrations have been associated with a longer time-to-pregnancy (TTP). However, the relationship between preconception serum PCBs concentrations and TTP has not been previously studied.
METHODS
Eighty-three women (contributing 442 menstrual cycles) planning pregnancies completed daily diaries regarding menstruation, intercourse, home pregnancy test results, and reported use of alcohol and cigarettes. TTP denoted the number of observed menstrual cycles required for pregnancy. Preconception blood specimens underwent toxicologic analysis for 76 PCB congeners via gas chromatography with electron capture; serum lipids were quantified with enzymatic methods. A priori, PCB congeners were summed into a total and three groupings—estrogenic, anti-estrogenic and other— and entered into discrete analogs of Cox models with time-varying covariates to estimate fecundability odds ratios (FOR) and corresponding 95% confidence intervals (CIs).
RESULTS
Estrogenic and anti-estrogenic PCB concentrations (ng/g serum) conferred reduced FORs in fully adjusted models (0.32; 95% CI 0.03, 3.90 and 0.01: 95% CI < 0.00, 1.99, respectively). Reduced FORs (0.96) were observed for alcohol consumption standardized to a 28-day menstrual cycle in the same adjusted model (FOR = 0.96; 95% CI 0.93, 1.00).
CONCLUSIONS
These data suggest that environmental exposures including those amenable to change, such as alcohol consumption, may impact female fecundity. The findings are sensitive to model specification and PCB groupings, underscoring the need to further assess the impact of chemical mixtures on sensitive reproductive outcomes, such as TTP, especially in the context of lifestyle factors which are amenable to change, thereby improving reproductive health.
doi:10.1093/humrep/den373
PMCID: PMC2628447  PMID: 18940895
time-to-pregnancy; polychlorinated biphenyls; fecundity; lifestyle; environment
9.  New approaches for genotyping paraffin wax embedded breast tissue from patients with cancer: the Iowa women’s health study 
Journal of Clinical Pathology  2005;58(9):955-961.
Background: The use of paraffin wax embedded tissue samples as a source of DNA for genotype analysis has been limited because of difficulties in DNA extraction and single nucleotide polymorphism (SNP) analysis.
Aims: To test the feasibility of applying the combination of a commonly used DNA isolation procedure, PureGene, and a high throughput SNP analysis method, the polymerase chain reaction (PCR)-INVADER assay, to genotype several types of paraffin wax embedded breast tissues.
Methods: Twenty formalin fixed, paraffin wax blocks were obtained from five participants in the Iowa women’s health study. Each participant provided several types of tissue including normal lymph node, normal nipple/areola tissue, inflammatory/fibrotic breast tissue, or normal breast tissue, and tumour tissue.
Results: Good quality DNA (260/280 ratio >1.6) was obtained from all tissues. Normal lymph nodes yielded the largest amount of DNA (97.1 μg). DNA obtained from the samples was tested for a germline C1183T polymorphism in the MnSOD gene by three methods—PCR-RFLP (restriction fragment length polymorphism), INVADER assay, and PCR-INVADER assay. Of the 20 samples, PCR-RFLP genotyped 16, the PCR-INVADER assay 18, and the INVADER assay two. This methodology was then used to analyse five additional genotypes and confirmed the general applicability of the method.
Conclusions: This study demonstrated the feasibility of (1) using several paraffin wax embedded breast tissues as a source of DNA for germline genetic analysis, with lymph nodes providing the highest yield, and (2) using the combination of a common extraction method with a high throughput SNP analysis method, the PCR–INVADER assay.
doi:10.1136/jcp.2004.023374
PMCID: PMC1770813  PMID: 16126877
Dna genotyping; paraffin wax embedded tissue blocks; single nucleotide polymorphisms
10.  Disease and Injury Among Participants in the Agricultural Health Study 
The Agricultural Health Study (www.aghealth.org) is a cohort of 89,658 pesticide applicators and their spouses from Iowa and North Carolina assembled between 1993 and 1997 to evaluate risk factors for disease in rural farm populations. This prospective study is just now reaching sufficient maturity for analysis of many disease endpoints. Nonetheless, several analyses have already provided interesting and important leads regarding disease patterns in agricultural populations and etiologic clues for the general population. Compared to the mortality experience of the general population in the two states (adjusted for race, gender, age and calendar time), the cohort experienced a very low mortality rate overall and for many specific causes and a low rate of overall cancer incidence. A few cancers, however, appear elevated, including multiple myeloma and cancers of the lip, gallbladder, ovary, prostate, and thyroid, but numbers are small for many cancers. A study of prostate cancer found associations with exposure to several pesticides, particularly among individuals with a family history of prostate cancer. Links to pesticides and other agricultural factors have been found for injuries, retinal degeneration, and respiratory wheeze. Methodological studies have determined that information collected by interview is unbiased and reliable. A third round of interviews scheduled to begin in 2005 will collect additional information on agricultural exposures and health outcomes. The study can provide data to address many health issues in the agricultural community. The study investigators welcome collaboration with interested scientists.
PMCID: PMC1237013  PMID: 15931940
Agriculture; Cancer; Farmers; Injuries; Mortality; Pesticides; Prospective study; Respiratory disease
11.  Mortality and cancer incidence among alachlor manufacturing workers 1968–99 
Background: Alachlor is the active ingredient in pre-emergent herbicide formulations that have been used widely on corn, soybeans, and other crops. It has been found to cause nasal, stomach, and thyroid tumours in rodent feeding studies at levels that are much higher than likely human exposures.
Aims: To evaluate mortality rates from 1968 to 1999 and cancer incidence rates from 1969 to 1999 for alachlor manufacturing workers at a plant in Muscatine, Iowa.
Methods: Worker mortality and cancer incidence rates were compared to corresponding rates for the Iowa state general population. Analyses addressed potential intensity and duration of exposure.
Results: For workers with any period of high alachlor exposure, mortality from all causes combined was lower than expected (42 observed deaths, SMR 64, 95% CI 46 to 86) and cancer mortality was slightly lower than expected (13 observed deaths, SMR 79, 95% CI 42 to 136). Cancer incidence for workers with potential high exposure was similar to that for Iowa residents, both overall (29 observed cases, SIR 123, 95% CI 82 to 177) and for workers exposed for five or more years and with at least 15 years since first exposure (eight observed cases, SIR 113, 95% CI 49 to 224). There were no cases of nasal, stomach, or thyroid cancer.
Conclusions: There were no cancers of the types found in toxicology studies and no discernible relation between cancer incidence for any site and years of alachlor exposure or time since first exposure. Despite the small size of this population, the findings are important because these workers had chronic exposure potential during extended manufacturing campaigns, while use in agriculture is typically limited to a few days or weeks each year.
doi:10.1136/oem.2003.010934
PMCID: PMC1740830  PMID: 15258274
12.  ATM variants 7271T>G and IVS10-6T>G among women with unilateral and bilateral breast cancer 
British Journal of Cancer  2003;89(8):1513-1516.
doi:10.1038/sj.bjc.6601289
PMCID: PMC2394328  PMID: 14562025
ATM gene screening; 7271T>G mutation; IVS10-6T>G mutation; breast cancer; bilateral breast cancer
13.  Occupational exposure to formaldehyde and wood dust and nasopharyngeal carcinoma 
OBJECTIVES—To investigate whether occupational exposures to formaldehyde and wood dust increase the risk of nasopharyngeal cancer (NPC).
METHODS—A multicentred, population based case-control study was carried out at five cancer registries in the United States participating in the National Cancer Institute's SEER program. Cases (n=196) with a newly diagnosed NPC between 1987 and 1993, and controls (n=244) selected over the same period from the general population through random digit dialing participated in structured telephone interviews which inquired about suspected risk factors for the disease, including a lifetime history of occupational and chemical exposure. Histological type of cancer was abstracted from clinical records of the registries. Potential exposure to formaldehyde and wood dust was assessed on a job by job basis by experienced industrial hygienists who were blinded as to case or control status.
RESULTS—For formaldehyde, after adjusting for cigarette use, race, and other risk factors, a trend of increasing risk of squamous and unspecified epithelial carcinomas was found for increasing duration (p=0.014) and cumulative exposure (p=0.033) but not for maximum exposure concentration. The odds ratio (OR) for people cumulatively exposed to >1.10 ppm-years was 3.0 (95% confidence interval (95% CI) 1.3 to 6.6) compared with those considered unexposed. In analyses limited to jobs considered definitely exposed, these trends became stronger. The associations were most evident among cigarette smokers. By contrast, there was no association between potential exposure to formaldehyde and undifferentiated and non-keratinising carcinomas. There was little evidence that exposure to wood dust increased risk of NPC, as modest crude associations essentially disappeared after control for potential exposure to formaldehyde.
CONCLUSIONS—These results support the hypothesis that occupational exposure to formaldehyde, but not wood dust, increases risk of NPC. This association seems to be specific to squamous cell carcinomas. Established cohorts of workers exposed to formaldehyde and wood dust should continue to be monitored for NPC and other respiratory cancers. Future studies of NPC should take into account histological type in assessing risk from environmental and host factors.


Keywords: occupational exposure; formaldehyde; wood dust
doi:10.1136/oem.57.6.376
PMCID: PMC1739963  PMID: 10810126
14.  Knowledge of the Tuskegee study and its impact on the willingness to participate in medical research studies. 
The under-representation of racial/ethnic minorities among medical research participants has recently resulted in mandates for their inclusion by the National Institutes of Health (NIH). Therefore, there is a need to determine how history, attitudes, cultural beliefs, social issues, and investigator behavior affect minority enrollment in medical research studies. From January 1998 to March 1999, 179 African-American and white residents of the Detroit Primary Metropolitan Statistical Area (PMSA) participated in a mail and telephone survey designed to examine impediments to African-American participation in medical research studies. Chi-square tests were performed to assess differences between the study groups using the Survey Data Analysis Program (SUDAAN). Eighty-one percent of African Americans and 28% of whites had knowledge of the Tuskegee Study (p = <0.001). Knowledge of the Tuskegee Study resulted in less trust of researchers for 51% of African-Americans and 17% of whites (p = 0.02). Forty-six percent of African-Americans and 34% of whites indicated that their knowledge of the study would affect future research participation decisions (p = 0.25). Of these, 49% of African-Americans and 17% of whites would not be willing to participate in future medical research studies (p = 0.05). This study confirms the need for medical researchers to confront the issue of the Tuskegee Study and its continuing impact on African-Americans' trust of medical research studies.
PMCID: PMC2568333  PMID: 11202759
15.  Use of methergine for the prevention of postoperative endometritis in non-elective cesarean section patients. 
OBJECTIVE: Methergine increases constriction of uterine musculature which may facilitate sloughing of endometrial debris, close uterine vessels, and prevent post-cesarean endometritis. The objective of this study was to evaluate the efficacy of methergine in preventing endometritis in patients undergoing non-elective cesarean section delivery. METHODS: Eighty patients undergoing non-elective cesarean section were enrolled in a prospective randomized clinical trial of methergine (41) versus no methergine (39) administration during the postpartum period. The hospital records were abstracted after discharge to compare the postpartum course. RESULTS: There were no significant demographic differences between the two groups. The women receiving methergine had a significant reduction in the rate of postoperative endometritis (10% vs. 36%, P < 0.005). In addition, the mean postoperative hemoglobin was significantly higher in the methergine treated group (P < 0.001). CONCLUSIONS: The use of methergine postpartum in women undergoing non-elective cesarean sections significantly reduces the incidence of postoperative endometritis and blood loss.
PMCID: PMC1784682  PMID: 10968597
16.  Medical libraries, bioinformatics, and networked information: a coming convergence? 
Libraries will be changed by technological and social developments that are fueled by information technology, bioinformatics, and networked information. Libraries in highly focused settings such as the health sciences are at a pivotal point in their development as the synthesis of historically diverse and independent information sources transforms health care institutions. Boundaries are breaking down between published literature and research data, between research databases and clinical patient data, and between consumer health information and professional literature. This paper focuses on the dynamics that are occurring with networked information sources and the roles that libraries will need to play in the world of medical informatics in the early twenty-first century.
PMCID: PMC226616  PMID: 10550026
17.  Exposure to atmospheric radon. 
Environmental Health Perspectives  1999;107(2):123-127.
We measured radon (222Rn) concentrations in Iowa and Minnesota and found that unusually high annual average radon concentrations occur outdoors in portions of central North America. In some areas, outdoor concentrations exceed the national average indoor radon concentration. The general spatial patterns of outdoor radon and indoor radon are similar to the spatial distribution of radon progeny in the soil. Outdoor radon exposure in this region can be a substantial fraction of an individual's total radon exposure and is highly variable across the population. Estimated lifetime effective dose equivalents for the women participants in a radon-related lung cancer study varied by a factor of two at the median dose, 8 mSv, and ranged up to 60 mSv (6 rem). Failure to include these doses can reduce the statistical power of epidemiologic studies that examine the lung cancer risk associated with residential radon exposure.
Images
PMCID: PMC1566320  PMID: 9924007
18.  Lymphogranuloma venereum presenting as a rectovaginal fistula. 
Lymphogranuloma venereum (LGV) is a rare form of the sexually transmitted disease caused by Chlamydia trachomatis. In the United States, there are fewer than 350 cases per year. In a review of the world's literature, there has not been a case reported in the last thirty years of a case of LGV presenting as a rectovaginal fistula. We present a case of an otherwise healthy American woman who presented with a rectovaginal fistula. Although uncommon, LGV does occur in developed countries and may have devastating tissue destruction if not recognized and treated before the tertiary stage.
doi:10.1002/(SICI)1098-0997(1999)7:4<199::AID-IDOG7>3.0.CO;2-K
PMCID: PMC1784745  PMID: 10449269
19.  Searching for the evidence in pre-hospital care: a review of randomised controlled trials. On behalf of the Ambulance Response Time Sub-Group of the National Ambulance Advisory Committee. 
OBJECTIVES: To identify randomised controlled trials (RCTs) which evaluate aspects of pre-hospital care; to perform categorisation by theme; to compare the sensitivity and precision of the search databases. DATA SOURCES: August 1997 updates of MEDLINE and EMBASE databases, using the Datastar online system. Papers published in 1987 or later were included, with no language restrictions. STUDY SELECTION: A trial was eligible for inclusion if it was judged, by two independent and blinded assessors, that participants followed up in the trial were definitely or possibly assigned prospectively to one of two or more alternative forms of healthcare with random allocation or a quasi-random method of allocation. RESULTS: The literature search retrieved 849 papers, of which 569 (67%) were in MEDLINE and 486 (57%) in EMBASE. Forty one (5%) were confirmed as reports of RCTs or quasi-RCTs, and the total number of individual trials was 38. Ten of these trials dealt with thrombolytic drugs; 14 were concerned with other drugs, 12 with equipment, and two with other interventions. Four trials were based on a sample size of more than 1000, and seven reported a statistically significant effect on mortality. All 41 papers were in EMBASE, and all but one were also in MEDLINE. CONCLUSIONS: Evidence based policy making with respect to the organisation of pre-hospital services cannot depend on RCTs. In the current relative absence of such evidence, practitioners and decision makers must use alternative information sources. A future review could examine a broader range of literature and be based on a wider search of published and unpublished material.
PMCID: PMC1343246  PMID: 9918280
20.  Factors associated with self-reported, pesticide-related visits to health care providers in the agricultural health study. 
Environmental Health Perspectives  1998;106(7):415-420.
To investigate factors associated with pesticide-related visits to health care providers (i.e., doctor or hospital visits), responses to self-administered questionnaires received from 35,879 licensed restricted-use pesticide applicators participating in the Agricultural Health Study were analyzed. (In Iowa, applicators are actually certified, whereas in North Carolina they are licensed; for ease of reference, the term license will be used for both states in this paper.) The cohort reported a total of more than 10.9 million pesticide-application days. These applications were associated with one or more pesticide-related health care visits by 2,214 applicators (7.0% of the applicator cohort for whom health care visit data were available). The odds of a pesticide-related health care visit were increased for commercial applicators compared to private applicators [odds ratio (OR = 1.77; 95% confidence interval (CI), 1.52-2.06) and for applicators who used insecticides 70 times or more in their lifetime compared to those who used insecticides less frequently (OR = 1.43; CI, 1.26-1.63). After adjusting for the number of applications in a logistic regression model, significantly higher odds of health care visits were observed among North Carolina applicators compared to Iowa applicators (OR = 1.35; CI, 1.17-1.52), among applicators who mixed their own pesticides (OR = 1.65; CI, 1. 22-2.23), and among applicators who personally repaired their pesticide application equipment at least once per year (OR = 1.12; CI, 1.06-1.25). Significantly lower odds were found among female versus male applicators (OR = 0.68; CI, 0.46-0.99) and among applicators who graduated from high school versus those who did not (OR = 0.82; CI, 0.71-0.94 for high school graduates and OR = 0.79; CI, 0.68-0.91 for those with at least some college). Several methods of pesticide application to crops, seed, or stored grain were also associated with significantly elevated odds ratios of health care visits. These observations suggest that several steps can be taken to reduce the number of health care visits resulting from occupational exposure to pesticides. The implications of this pattern of pesticide-related health care visits may have etiologic implications for cancer and other chronic diseases.
Images
PMCID: PMC1533128  PMID: 9637799
21.  Active efflux of antimicrobial agents in wild-type strains of enterococci. 
Enterococci are intrinsically resistant to numerous antimicrobial agents. We examined the energy-dependent efflux of radiolabeled drugs from four reference strains of Enterococcus faecalis and a strain of Enterococcus faecium and found that most strains pumped out norfloxacin and chloramphenicol. Efflux of tetracycline was detected only in certain strains.
PMCID: PMC163815  PMID: 9087510
22.  Intrauterine growth retardation in Iowa communities with herbicide-contaminated drinking water supplies. 
Environmental Health Perspectives  1997;105(3):308-314.
In a statewide survey of 856 Iowa municipal drinking water supplies in 1986-1987 the Rathbun rural water system was found to contain elevated levels of triazine herbicides. Rates of low birth weight, prematurity, and intrauterine growth retardation (IUGR) in live singleton births during the period 1984-1990 by women living in 13 communities served by the Rathbun water system were compared to other communities of similar size in the same Iowa counties. The Rathbun communities had a greater risk of IUGR than southern Iowa communities with other surface sources of drinking water (relative risk = 1.8; 95% CI = 1.3, 2.7). Multiple linear regression analyses revealed that levels of the herbicides atrazine, metolachlor, and cyanzinc were each significant predictors of community IUGR rates in southern Iowa after controlling for several potentially confounding factors including maternal smoking and socioeconomic variables. The association with IUGR was strongest for atrazine, but all three herbicides were intercorrelated and the independent contributions of each to IUGR risk could not be determined. We conclude that communities in southern Iowa with drinking water supplies contaminated with herbicides have elevated rates of IUGR compared to neighboring communities with different water supplies. Because of the limitations of the ecologic design of this study, including aggregate rather than individual measures of exposure and limited ability to control for confounding factors related to source of drinking water and risk of IUGR, a strong causal relationship between any specific water contaminant and risk of IUGR cannot yet be inferred. The association between the water supplied to the Rathbun communities and the increased risk of IUGR should be considered a preliminary finding that needs to be verified by more detailed epidemiologic studies.
PMCID: PMC1470002  PMID: 9171992
23.  Evaluation of mortality and cancer incidence among alachlor manufacturing workers. 
Environmental Health Perspectives  1996;104(7):728-733.
Alachlor is the active ingredient in a family of preemergence herbicides. We assessed mortality rates from 1968 to 1993 and cancer incidence rates from 1969 to 1993 for manufacturing workers with potential alachlor exposure. For workers judged to have high alachlor exposure, mortality from all causes combined was lower than expected [23 observed, standardized mortality ratio (SMR) = 0.7, 95% CI, 0.4-1.0], cancer mortality was similar to expected (6 observed, SMR = 0.7, 95% CI, 0.3-1.6), and there were no cancer deaths among workers with 5 or more years high exposure and 15 or more years since first exposure (2.3 expected, SMR = 0, 95% CI, 0-1.6). Cancer incidence for workers with high exposure potential was similar to the state rate [18 observed, standardized incidence ratio (SIR) = 1.2, 95% CI, 0.7-2.0], especially for workers exposed for 5 or more years and with at least 15 years since first exposure (4 observed, SIR = 1.0, 95% CI, 0.3-2.7). The most common cancer for these latter workers was colorectal cancer (2 observed, SIR 3.9, 95% CI, 0.5-14.2 among workers). Despite the limitations of this study with respect to small size and exposure estimating, the findings are useful for evaluating potential alachlor-related health risks because past manufacturing exposures greatly exceeded those characteristic of agricultural operations. These findings suggest no appreciable effect of alachlor exposure on worker mortality or cancer incidence rates during the study period.
PMCID: PMC1469394  PMID: 8841758
24.  The Agricultural Health Study. 
Environmental Health Perspectives  1996;104(4):362-369.
The Agricultural Health Study, a large prospective cohort study has been initiated in North Carolina and Iowa. The objectives of this study are to: 1) identify and quantify cancer risks among men, women, whites, and minorities associated with direct exposure to pesticides and other agricultural agents; 2) evaluate noncancer health risks including neurotoxicity reproductive effects, immunologic effects, nonmalignant respiratory disease, kidney disease, and growth and development among children; 3) evaluate disease risks among spouses and children of farmers that may arise from direct contact with pesticides and agricultural chemicals used in the home lawns and gardens, and from indirect contact, such as spray drift, laundering work clothes, or contaminated food or water; 4) assess current and past occupational and nonoccupational agricultural exposures using periodic interviews and environmental and biologic monitoring; 5) study the relationship between agricultural exposures, biomarkers of exposure, biologic effect, and genetic susceptibility factors relevant to carcinogenesis; and 6) identify and quantify cancer and other disease risks associated with lifestyle factors such as diet, cooking practices, physical activity, smoking and alcohol consumption, and hair dye use. In the first year of a 3-year enrollment period, 26,235 people have been enrolled in the study, including 19,776 registered pesticide applicators and 6,459 spouses of registered farmer applicators. It is estimated that when the total cohort is assembled in 1997 it will include approximately 75,000 adult study subjects. Farmers, the largest group of registered pesticide applicators comprise 77% of the target population enrolled in the study. This experience compares favorably with enrollment rates of previous prospective studies.
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PMCID: PMC1469343  PMID: 8732939
25.  Long-term biological response of injured rat carotid artery seeded with smooth muscle cells expressing retrovirally introduced human genes. 
Journal of Clinical Investigation  1994;93(2):644-651.
Cultured vascular smooth muscle cells (SMCs) containing retrovirally introduced genes are a potential vehicle for gene replacement therapy. Because the cultured SMCs are selected for their ability to proliferate in vitro, it is possible that the SMCs might be permanently altered and lose their capacity to respond to growth-suppressing conditions after being seeded back into blood vessels. To investigate this possibility we measured SMC proliferation and intimal thickening in balloon-injured Fischer 344 rat carotid arteries seeded with SMCs stained with the fluorescent marker 1,1'-dioctadecyl-3,3,3',3'-tetramethylindo-carbocyanine perchlorate (DiI) and infected with replication-defective retrovirus expressing human adenosine deaminase or human placental alkaline phosphatase. The majority of the seeded SMCs remained in the intima while a few of the cells appeared to migrate into the first layer of the media. Intimal SMC proliferation returned to background levels (< 0.1% thymidine labeling index) by 28 d. At late times (1 and 12 mo) the morphological appearance of the intima was the same for balloon-injured arteries with or without seeded SMC, except that the seeded arteries continued to express human adenosine deaminase or alkaline phosphatase. These results support the conclusion that cultured SMC infected with a replication-defective virus containing human adenosine deaminase or alkaline phosphatase are not phenotypically altered and do not become transformed. After seeding onto the surface of an injured artery, they stop replicating but continue to express the introduced human genes even over the long term.
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PMCID: PMC293889  PMID: 8113400

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