Beta-blockers are associated with incident heart failure: a secondary analysis of the systolic blood pressure intervention (SPRINT) trial

Background

The Systolic Blood Pressure Intervention Trial (SPRINT) evaluated whether a blood pressure (BP) goal of less than 120mmHg versus less than 140mmHg would reduce cardiovascular outcomes in subjects with at least one cardiovascular risk factor and without heart failure. Participating investigators were encouraged to use any antihypertensive medication class with a strong evidence base. The SPRINT trial was halted early due to a lower rate of the composite primary outcome in the 120mmHg group, which was mainly driven by a reduction in heart failure (HF).

Objective

As there is a concern that beta-blocker use may be associated with an excess risk for incident HF in subjects with a normal left ventricular systolic function, we evaluated the association between beta-blocker use and HF. Beta-blockers were compared with other major classes of antihypertensive medications. We also studied the association of antihypertensive class with loop-diuretic initiation.

Methods and results

In the 9,012 subjects, without HF at baseline, the association of beta-blocker exposure and incident HF was examined using time-variant competing risk analysis. Beta-blocker exposure was associated with an increased HF risk (HR 1.18; CI 1.07–1.30; p<0.001) and more frequent and earlier loop diuretic-use compared to other antihypertensive agents (both p<0.01). Sensitivity analyses of propensity-score matched cohorts confirmed a strong association of beta-blocker use and HF. Other major antihypertensive medication classes did not show this association.

Conclusions

Beta-blocker exposure was associated with a higher incidence of HF in hypertensive subjects without HF at baseline.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health

Transcriptomic changes in the nasal epithelium associated with diesel engine exhaust exposure

BACKGROUND

Diesel engine exhaust (DEE) exposure causes lung cancer, but the molecular mechanisms by which this occurs are not well understood.

OBJECTIVES

To assess transcriptomic alterations in nasal epithelium of DEE-exposed factory workers to better understand the cellular and molecular effects of DEE.

METHODS

Nasal epithelial brushings were obtained from 41 diesel engine factory workers exposed to relatively high levels of DEE (17.2-105.4 μg/m3), and 38 unexposed workers from factories without DEE exposure. mRNA was profiled for gene expression using Affymetrix microarrays. Linear modeling was used to identify differentially expressed genes associated with DEE exposure and interaction effects with current smoking status. Pathway enrichment among differentially expressed genes was assessed using EnrichR. Gene Set Enrichment Analysis (GSEA) was used to compare gene expression patterns between datasets.

RESULTS

225 genes had expression associated with DEE exposure after adjusting for smoking status (FDR q < 0.25) and were enriched for genes in pathways related to oxidative stress response, cell cycle pathways such as MAPK/ERK, protein modification, and transmembrane transport. Genes up-regulated in DEE-exposed individuals were enriched among the genes most up-regulated by cigarette smoking in a previously reported bronchial airway smoking dataset. We also found that the DEE signature was enriched among the genes most altered in two previous studies of the effects of acute DEE on PBMC gene expression. An exposure-response relationship was demonstrated between air levels of elemental carbon and the first principal component of the DEE signature.

CONCLUSIONS

A gene expression signature was identified for workers occupationally exposed to DEE that was altered in an exposure-dependent manner and had some overlap with the effects of smoking and the effects of acute DEE exposure. This is the first study of gene expression in nasal epithelial cells of workers heavily exposed to DEE and provides new insights into the molecular alterations that occur with DEE exposure.

Prediction of non-muscle invasive bladder cancer outcomes assessed by innovative multimarker prognostic models

Background

We adapted Bayesian statistical learning strategies to the prognosis field to investigate if genome-wide common SNP improve the prediction ability of clinico-pathological prognosticators and applied it to non-muscle invasive bladder cancer (NMIBC) patients.

Methods

Adapted Bayesian sequential threshold models in combination with LASSO were applied to consider the time-to-event and the censoring nature of data. We studied 822 NMIBC patients followed-up >10 years. The study outcomes were time-to-first-recurrence and time-to-progression. The predictive ability of the models including up to 171,304 SNP and/or 6 clinico-pathological prognosticators was evaluated using AUC-ROC and determination coefficient.

Results

Clinico-pathological prognosticators explained a larger proportion of the time-to-first-recurrence (3.1 %) and time-to-progression (5.4 %) phenotypic variances than SNPs (1 and 0.01 %, respectively). Adding SNPs to the clinico-pathological-parameters model slightly improved the prediction of time-to-first-recurrence (up to 4 %). The prediction of time-to-progression using both clinico-pathological prognosticators and SNP did not improve. Heritability (ĥ²) of both outcomes was <1 % in NMIBC.

Conclusions

We adapted a Bayesian statistical learning method to deal with a large number of parameters in prognostic studies. Common SNPs showed a limited role in predicting NMIBC outcomes yielding a very low heritability for both outcomes. We report for the first time a heritability estimate for a disease outcome. Our method can be extended to other disease models.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2361-7) contains supplementary material, which is available to authorized users.

Diabetes, antidiabetic medications, and pancreatic cancer risk: an analysis from the International Pancreatic Cancer Case-Control Consortium

BACKGROUND

Type 2 diabetes mellitus has been associated with an excess risk of pancreatic cancer, but the magnitude of the risk and the time-risk relationship are unclear, and there is limited information on the role of antidiabetic medications.

PATIENTS AND METHODS

We analyzed individual-level data from 15 case-control studies within the Pancreatic Cancer Case-Control Consortium, including 8305 cases and 13 987 controls. Pooled odds ratios (ORs) were estimated from multiple logistic regression models, adjusted for relevant covariates.

RESULTS

Overall, 1155 (15%) cases and 1087 (8%) controls reported a diagnosis of diabetes 2 or more years before cancer diagnosis (or interview, for controls), corresponding to an OR of 1.90 (95% confidence interval, CI, 1.72-2.09). Consistent risk estimates were observed across strata of selected covariates, including body mass index and tobacco smoking. Pancreatic cancer risk decreased with duration of diabetes, but a significant excess risk was still evident 20 or more years after diabetes diagnosis (OR 1.30, 95% CI 1.03-1.63). Among diabetics, long duration of oral antidiabetic use was associated with a decreased pancreatic cancer risk (OR 0.31, 95% CI 0.14-0.69, for ≥15 years). Conversely, insulin use was associated with a pancreatic cancer risk in the short term (OR 5.60, 95% CI 3.75-8.35, for <5 years), but not for longer duration of use (OR 0.95, 95% CI 0.53-1.70, for ≥15 years).

CONCLUSION

This study provides the most definitive quantification to date of an excess risk of pancreatic cancer among diabetics. It also shows that a 30% excess risk persists for more than two decades after diabetes diagnosis, thus supporting a causal role of diabetes in pancreatic cancer. Oral antidiabetics may decrease the risk of pancreatic cancer, whereas insulin showed an inconsistent duration-risk relationship.

Antibodies in autoimmune thyroiditis affect glucose metabolism of anterior cingulate

BACKGROUND

Hypothyroidism induced by an autoimmune process is associated with neuropsychiatric symptoms and metabolic abnormalities in the brain. The aim of this study was to examine the relationship between autoimmune thyroiditis and regional brain function in hypothyroid patients.

METHODS

Cerebral glucose metabolism, as an index of brain function, was assessed in regional whole-brain analyses using positron emission tomography (PET) and [18F]fluorodeoxyglucose in thirteen hypothyroid patients with autoimmune thyroiditis suffering from neuropsychiatric symptoms. The primary biological measures were radioactivity in pre-selected brain regions, relative to whole-brain radioactivity, as a surrogate index of glucose metabolism, and serum levels of thyroglobulin (TG) and thyroid peroxidase (TPO) antibodies as endocrine markers of autoimmune thyroiditis.

RESULTS

Serum levels of anti-TG antibodies in hypothyroid patients were significantly correlated with glucose metabolism in the perigenual anterior cingulate cortex, a brain region previously shown to regulate affect and emotional homeostasis.

CONCLUSION

Thyroid autoimmune processes may play an important role in the still poorly defined pathogenic correlates of disturbed function in brain regions critically involved in emotional processing in hypothyroid conditions.

First Report of the Occurrence and Resistance to Mefenoxam of Peronospora belbahrii, Causal Agent of Downy Mildew of Basil (Ocimum basilicum) in Israel

Downy mildew in basil was first reported from Uganda in 1933 (4). In 2004, it was reported from Italy (3) and, thereafter, from other countries around the world. In Israel, the disease was first observed in November 2011 in two greenhouses located in the northern part of the Jordan Valley. Within a month, second and third outbreaks of the disease occurred simultaneously near the southwest and southeast borders of Israel, 250 km from the initial disease outbreak. By the summer of 2012, the disease had appeared throughout the country, causing major economic damage. The causal agent, identified as Peronospora belbahrii (see below), produced chlorotic lesions on leaf blades with sporangia developing on the lower leaf surfaces. Lesions gradually turn necrotic, and infected leaves abscised. Sporangia were dark purple, oval, 30.4 ± 2.9 μm long × 21.4 ± 1.7 μm wide. Sporangiophores emerged from stomatal openings in a saturated atmosphere, were hyaline, 400 to 600 μm long, dichotomously branched, with three to five branches per sporangiophore, and bore a single sporangium on each branchlet tip. Oospores, seldom seen, were brown, round, and 46.2 ± 2.8 μm in diameter. Sporangia germinated directly, each producing a single germ tube that penetrated the periclinal wall of epidermal cells. PCR assays using sporangia and infected leaves as the template, and specific BAZ primers (1), produced a 134-bp band typical of P. belbahrii (1,2). Twenty isolates, collected from 12 locations in Israel from December 2011 to September 2012, were all sensitive to mefenoxam as the isolates did not cause symptoms on 15-leaf, potted basil plants (cv. Peri, Volcani Center, Israel) that were sprayed with 10 μg mefenoxam/ml (Ridomil Gold 48%, Syngenta, Basel, Switzerland) prior to inoculation. However, one isolate collected in early October 2012 from a severely infected plant in a greenhouse at Rehov in Bet-Shaan Valley, in which the plants had been treated with mefenoxam, was resistant to mefenoxan, showing abundant sporulation on leaves of potted basil plants that had been sprayed with 1,000 μg of mefenoxam/ml prior to inoculation. To our knowledge, this is the first report of the occurrence of downy mildew in basil in Israel. This is also the first global report of resistance to mefenoxam in P. belbahrii. References: (1) L. Belbahri et al. Mycol. Res. 109:1276, 2005. (2) R. Djalali et al. Mycol. Progress 11:961, 2012. (3) A. Garibaldi et al., Plant Dis. 89:683, 2004. (4) C. G. Hansford. Rev. Appl. Mycol. 12:421, 1933.

Alcohol consumption and pancreatic cancer: a pooled analysis in the International Pancreatic Cancer Case-Control Consortium (PanC4)

BACKGROUND

Heavy alcohol drinking has been related to pancreatic cancer, but the issue is still unsolved.

METHODS

To evaluate the role of alcohol consumption in relation to pancreatic cancer, we conducted a pooled analysis of 10 case-control studies (5585 cases and 11,827 controls) participating in the International Pancreatic Cancer Case-Control Consortium. We computed pooled odds ratios (ORs) by estimating study-specific ORs adjusted for selected covariates and pooling them using random effects models.

RESULTS

Compared with abstainers and occasional drinkers (< 1 drink per day), we observed no association for light-to-moderate alcohol consumption (≤ 4 drinks per day) and pancreatic cancer risk; however, associations were above unity for higher consumption levels (OR = 1.6, 95% confidence interval 1.2-2.2 for subjects drinking ≥ 9 drinks per day). Results did not change substantially when we evaluated associations by tobacco smoking status, or when we excluded participants who reported a history of pancreatitis, or participants whose data were based upon proxy responses. Further, no notable differences in pooled risk estimates emerged across strata of sex, age, race, study type, and study area.

CONCLUSION

This collaborative-pooled analysis provides additional evidence for a positive association between heavy alcohol consumption and the risk of pancreatic cancer.

Combined NMR and computational study for azide binding to human manganese superoxide dismutase

Human manganese superoxide dismutase (MnSOD) labeled with 3-fluorotyrosine (Tyf) was complexed with the (15)N-labeled inhibitor azide ([(15)N(3)(-)]). The sample was characterized by solid-state NMR (SSNMR) spectroscopy ((19)F-MAS and (15)N-CPMAS). Employing (19)F-(15)N-REDOR spectroscopy, we determined the distances between the fluorine label in Tyrosine-34 and the three (15)N-nuclei of the azide and the relative orientation of the azide in the binding pocket of the MnSOD. A distance of R(1)=4.85A between the (19)F-label of Tyf34 and the nearest (15)N of the azide and an azide-fluorotyrosine Tyf34 angle of 90 degrees were determined. These geometry data are employed as input for molecular modeling of the location of the inhibitor in the active site of the enzyme. In the computations, several possible binding geometries of the azide near the Mn-complex were assumed. Only when the azide replaces the water ligand at the Mn-complex we obtained a geometry of the azide-Mn-complex, which is consistent with the present NMR data. This indicates that the water molecule ligating to the Mn-complex is removed and the azide is placed at this position. As a consequence the azide forms an H bond with Gln143 instead with Tyf34, in contrast to non-(19)F-labeled MnSOD, where the azide is hydrogen bonded to the hydroxy group of Tyr34.

Benign prostatic hyperplasia and subsequent risk of bladder cancer

We evaluated the risk of bladder cancer in a cohort of 79,280 Swedish men hospitalised for benign prostatic hyperplasia (BPH), identified in the Swedish Inpatient Register between 1964 and 1983 and followed until 1989 via multiple record linkages with nationwide data on cancer registry, death and emigration. Standardised incidence ratios (SIRs), the ratios of the observed to the expected numbers of incident bladder cancers, were used to calculate the risk associated with BPH. The expected number was calculated by multiplying the number of person-years by the age-specific cancer incidence rates in Sweden for each 5-year age group and calendar year of observation. Analyses were stratified by BPH treatment, latency, calendar year and presence of genitourinary (GU) comorbid conditions. After excluding the first 3 years of follow-up after the index hospitalisation, we observed 506 incident bladder cancer cases during follow-up in the cohort. No overall increased risk of bladder cancer was apparent in our main analysis involving the entire BPH cohort. However, among BPH patients with transurethral resection of the prostate (TURP), there was an increased risk in all follow-up periods; SIRs of bladder cancer during years 4-6 of follow-up was 1.22 (95% confidence interval=1.02-1.46), 1.32 for 7-9 years of follow-up, and 1.47 for 10-26 years of follow-up. SIRs of bladder cancer among TURP-treated BPH patients were particularly elevated among those with comorbid conditions of the GU tract (e.g., stone, infection, etc.); 1.72, 1.74 and 2.01 for 4-6, 7-9, 10-26 years of follow-up, respectively, and also for those whose diagnoses occurred before 1975, when TURP was more likely to be performed by a urologist than a general practitioner: 1.87, 1.90 and 1.74, respectively. These findings suggest that BPH overall is not associated with bladder cancer risk. However, among men treated with TURP, particularly those with other comorbid GU tract conditions, risk of bladder cancer was elevated.

Assessment of lifetime exposure to trihalomethanes through different routes

OBJECTIVES

To evaluate lifetime exposure to trihalomethanes (THM) through ingestion, inhalation, and dermal absorption in a hospital based case-control study of bladder cancer conducted between 1998 and 2001 in five areas of Spain. The study base was comprised of subjects living in the catchment areas of the participating hospitals.

METHODS

Individual information on water related habits was obtained from personal interviews of 1219 cases and 1271 controls: residential and occupational history, drinking water source at each residence and job, amount of water consumption, frequency and duration of showering, bathing, and swimming pool attendance. THM levels, water source history, and year when chlorination started in study areas were ascertained through measurements in drinking water samples and questionnaires to water companies and local authorities. Estimates of THM levels covered 79% of the subjects' person-years of exposure.

RESULTS

Current and historical average THM levels in water were correlated. Control subjects reported that drinking water source in the last residence was municipal for 63%, bottled for 22%, private well for 2%, and other sources for 13%. For the time window between age 15 and the time of interview, average residential THM level was 32.2 mug/l. THM exposure through ingestion was 23.7 mug/day on average, and was correlated with the ingestion THM level in the workplace. Overall, 79% usually took showers, 16% usually took baths, and 13% had ever attended a swimming pool. Between 21% and 45% of controls unexposed to THM through ingestion were evaluated as moderately or highly exposed through showering or bathing, and 5-10% were exposed through swimming in pools.

CONCLUSION

The importance of evaluating different routes is underscored by findings from experimental studies showing substantial differences in THM uptake and internal distribution by route.

Cost-effectiveness of 18F-fluorodeoxyglucose positron emission tomography in the assessment of early dementia from a Belgian and European perspective

(18)F-fluoro-deoxyglucose positron emission tomography (FDG PET) can aid to predict AD in an early stage. The aim of this study was to estimate the economic effects of incorporating FDG PET in the diagnostic work-up of AD in a Belgian and European setting. A decision tree analysis was followed comparing a conventional algorithm using diagnostic clinical criteria and one that also incorporates PET. Major outcome terms were overall cost per patient in either strategy; diagnostic accuracy and cost per accurate diagnosis. A sensitivity analysis was performed for four critical variables: cost of PET, sensitivity and specificity of PET and delay in cognitive decline because of appropriate medication. Cost-savings per accurate diagnosis ranged from 623-6110 Euro in favour of the proposed algorithm with PET. For the same cost, more accurate diagnoses were made, resulting in benefit for patients and society. The positive results were maintained over a wide range of values for the critical variables and were expandable to other European countries with a similar health system. Therefore, incorporation of FDG PET into the clinical diagnostic work up of patients with early symptoms of cognitive decline can be advocated.

Lung cancer in heavy equipment operators and truck drivers with diesel exhaust exposure in the construction industry

BACKGROUND

Several studies indicate that truck drivers have an increased risk of lung cancer, but few studies have examined lung cancer risk in heavy equipment operators. Workers in both occupations are exposed to diesel exhaust.

AIMS

To examine the incidence and mortality from lung cancer among truck drivers and among drivers of heavy vehicles.

METHODS

A computerised register of Swedish construction workers participating in health examinations between 1971 and 1992 was used. Male truck drivers (n = 6364) and drivers of heavy construction vehicles (n = 14 364) were selected as index groups; carpenters/electricians constituted the reference group (n = 119 984).

RESULTS

Operators of heavy construction equipment experienced no increased risk of lung cancer compared to risk among the carpenter/electrician referents (61 cases v 70.1 expected). However, a significant inverse trend risk with increasing use of cabins was apparent. Truck drivers had increased risks of cancer of the lung (61 cases v 47.3 expected) and prostate (124 cases v 99.7 expected), although only mortality for lung cancer was significantly increased. Comparisons with the general population showed similar results.

CONCLUSION

Results are consistent with those of previous studies suggesting that heavy equipment operators with potential exposure to diesel exhaust may have little or no increased risk of lung cancer, although the use of cabins seemed to decrease the risk of lung cancer. The results for truck drivers are also consistent with previous reports of increased lung cancer risk among truck drivers exposed to diesel exhaust, as well as recent reports linking diesel exhaust exposure to prostate cancer.

Is your patient taking the medicine? A simple assay to measure compliance with 5-aminosalicylic acid-containing compounds

BACKGROUND

Poor compliance with 5-aminosalicylic acid therapy has been reported amongst patients with inflammatory bowel disease. Currently, there is no easy method to monitor 5-aminosalicylic acid; however, the chemical similarity between 5-aminosalicylic acid and salicylate might provide a solution.

AIM

To determine the feasibility of using salicylate levels to monitor compliance with 5-aminosalicylic acid medication.

METHODS

Thirty-six patients with inflammatory bowel disease, taking maintenance 5-aminosalicylic acid, provided either a paired serum and urine sample or an intestinal biopsy. Samples were split into two: half were sent to the hospital biochemistry department for salicylate measurement, and half were analysed for 5-aminosalicylic acid and its metabolite, N-acetyl-5-aminosalicylic acid, using high performance liquid chromatography. Correlation between the results was calculated.

RESULTS

Serum and urine were available for 25 patients. Serum salicylate was undetectable, but urinary salicylate ranged from 31 to 3254 microg/mL. The correlations between urinary salicylate and 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid were 0.96 (95% confidence interval, 0.91-0.98) and 0.9 (95% confidence interval, 0.77-0.96), respectively. Sixteen biopsies were available from 13 patients. The 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid concentrations were 0.2-657 ng/mg and 1.6-1598 ng/mg, respectively; there was no correlation with bowel salicylate.

CONCLUSIONS

The close correlation between 5-aminosalicylic acid and salicylate levels offers a simple method to assess compliance with 5-aminosalicylic acid therapy.

Occupational exposure to diesel engine emissions and risk of cancer in Swedish men and women

OBJECTIVE

To investigate the risk of cancer among workers exposed to diesel emissions in a large record-linkage study from Sweden.

METHODS

The Swedish Cancer Environment Register III contains nationwide data on cancer incidence during 1971-1989, by occupation and industry of employment as reported in the 1960 and 1970 censuses. After excluding farmers, we classified job and industry titles according to estimated probability and intensity of exposure to diesel emissions. Exposed men in the 1960 census contributed over 7,400,000 person-years, and exposed women contributed over 240,000. We compared them to the remainder of the employed population, using indirect standardization and multivariate Poisson regression analysis.

RESULTS

Men exposed in the 1960 census experienced an increased risk of lung cancer: the relative risks (RRs) were 0.95 (95% confidence interval [CI] 0.9-1.0), 1.1 (1.1-1.2) and 1.3 (1.3-1.4) for low, medium, and high intensity of exposure. Corresponding results for probability of exposure were 1.1 (1.0-1.1), 0.9 (0.86-0.94) and 1.2 (1.1-1.2). The risk was higher for squamous cell carcinoma of the lung than for other histological types. Results in women were not suggestive of an effect (RR in the category of medium or high intensity of exposure 1.1, 95% CI 0.6-1.8). A small but significant increase in risk of cancers of the stomach (SIR 1.06), pancreas (SIR 1.05), larynx (SIR 1.09), and the kidney (SIR 1.06) was present among men exposed to diesel emissions, without a clear trend according to either probability or intensity of exposure. The SIR among women was non-significantly increased for stomach, pancreatic, and laryngeal cancers, but not for kidney cancer. Furthermore, a significantly increased risk of oral/pharyngeal (SIR 1.64) and cervical (SIR 1.48) cancers was present among women, with a suggestion of a dose-response relationship. There was no increased risk of bladder cancer in either gender.

CONCLUSIONS

The results of this study provide evidence of a positive exposure-response relationship between exposure to diesel emissions and lung cancer risk among men. The positive results for other neoplasms, such as stomach, pancreatic, oral/pharyngeal, and cervical cancers, cannot be attributed to diesel exposure, but they deserve attention in future investigations.

Excess incidence of squamous cell esophageal cancer among US Black men: role of social class and other risk factors

Data from a population-based case-control study were used to evaluate the relation between social class factors and squamous cell esophageal cancer and the extent to which alcohol, tobacco, diet, and low income contribute to the higher incidence among Black men than among White men in the United States. A total of 347 male cases (119 White, 228 Black) and 1,354 male controls (743 White, 611 Black) were selected from three US geographic areas (Atlanta, Georgia, Detroit, Michigan, and New Jersey). Cases were residents of the study areas aged 30-79 years who had been diagnosed with histologically confirmed esophageal cancer between 1986 and 1989. The adjusted odds ratios for subjects with annual incomes less than $10,000 versus incomes of $25,000 or more were 4.3 (95% confidence interval: 2.1, 8.7) for Whites and 8.0 (95% confidence interval: 4.3, 15.0) for Blacks. The combination of all four major risk factors-low income, moderate/heavy alcohol intake, tobacco use, and infrequent consumption of raw fruits and vegetables-accounted for almost all of the squamous cell esophageal cancers in Whites (98%) and Blacks (99%) and for 99% of the excess incidence among Black men. Thus, lifestyle modifications, especially a lowered intake of alcoholic beverages, would markedly decrease the incidence of squamous cell esophageal cancer in both racial groups and would narrow the racial disparity in risk. Further studies on the determinants of social class may help to identify a new set of exposures for this tumor that are amenable to intervention.

The excess incidence of squamous cell esophageal cancer among us black men. Role of social class and other risk factors

PURPOSE: To investigate the relationship between social class factors and squamous cell esophageal cancer and the extent to which alcohol, tobacco, diet, and social class contribute to the five-fold higher incidence among black than white men in the United States.METHODS: Interviews were conducted with 347 incident cases of squamous cell esophageal cancer (119 white males and 228 black males) and 1354 population-based controls (743 white males and 611 black males) from Atlanta, Detroit, and New Jersey. Risks were estimated using unconditional logistic regression controlling for potential confounders.RESULTS: Elevated risks of squamous cell esophageal cancer were associated with indicators of low social class, especially low annual income. The adjusted odds ratios (ORs) for subjects with incomes < $10,000 versus incomes of $25,000 or more were 4.3 (95% CI = 2.1-8.7) for whites and 8.0 (95% CI = 4.3-15.0) for blacks. The combination of all four major risk factors: annual income less than $25,000, moderate/heavy use of alcohol, use of tobacco for six months or longer, and consumption of less than 2.5 servings of raw fruits and vegetables per day accounted for almost all of the squamous cell esophageal cancers in whites (98%) and blacks (99%), and for 99% of the excess incidence among black men.CONCLUSIONS: Lifestyle modifications, especially a lower intake of alcoholic beverages, would markedly decrease the incidence of this cancer in both races and narrow the racial disparity in risk. Further studies into the determinants of social class may help identify a new set of exposures for this tumor that are amendable to intervention.

Gender differences in regional brain response to visceral pressure in IBS patients

In two experiments including a total of 30 irritable bowel syndrome patients, symptom-mimicking rectal pressure stimuli elicited changes in regional neural activation as measured by positron electron tomography (PET) cerebral blood flow images. Although most stimuli were not rated as painful, rectal pressure increased regional cerebral blood flow (rCBF) in areas commonly associated with somatic pain, including the anterior cingulate, insula, prefrontal cortex, thalamus, and cerebellum. Despite similar stimulus ratings in male and female patients, regional activations were much stronger for males. In both experiments, rectal pressure activated the insula bilaterally in males but not in females. Insula activation was associated most strongly with objective visceral pressure, whereas anterior cingulate activation was associated more with correlated ratings of subjective discomfort. The insula is discussed as a visceral sensory cortex. Several possible reasons for the insula gender effect are proposed.

Prevalence of myocardial viability as detected by positron emission tomography in patients with ischemic cardiomyopathy

BACKGROUND

Detection of myocardial viability is important in patients with ischemic cardiomyopathy. Restoration of blood flow to viable myocardium is associated with improved left ventricular function and improved patient prognosis. However, the prevalence of viable myocardium in patients with ischemic cardiomyopathy is unknown.

METHODS AND RESULTS

To determine the prevalence of myocardial viability, clinical [13N]ammonia/18F-deoxyglucose PET studies performed in 283 patients (age, 63+/-10 years) with ischemic heart disease (mean ejection fraction, 26+/-8%) were visually analyzed for the presence and extent of viable and nonviable myocardium. The myocardium was divided into 19 segments. The extent of viable myocardium was considered "functionally" significant if >/=5 segments ( approximately 25% of the left ventricular myocardium) exhibited a blood flow/metabolism mismatch and "prognostically" significant if 1 to 4 left ventricular segments did so. Of all patients, 41% had no evidence of viable myocardium, 55% had viable myocardium, and 4% had normal blood flow and metabolism within an enlarged left ventricle. Functionally significant viability was found in 27% and prognostically significant viability in 28% of the patients. Multivariate analysis revealed the presence of angina to be the only clinical parameter associated with the presence of functionally significant viability.

CONCLUSIONS

Revascularization might improve patient prognosis in 55% and result in improved left ventricular function in 27% of all patients with ischemic cardiomyopathy.

Percutaneous treatment of small hepatic tumors by an expandable RF needle electrode

OBJECTIVE

The aim of this study was to evaluate the usefulness of expandable RF needle electrodes in the treatment of hepatic cancer.

SUBJECTS AND METHODS

Thirty-seven patients, 23 of whom had 26 hepatocellular carcinoma nodules and 14 of whom had 19 hepatic metastatic nodules, underwent treatment by RF interstitial thermal ablation with expandable needle electrodes. Forty-five tumor nodules were treated in 64 RF interstitial thermal ablation sessions with 83 needle electrode insertions. The mean diameter of the tumor nodules was 2.5 cm (range, 1.1-3.5 cm). Immediate posttreatment tumor necrosis was evaluated by dynamic CT in all cases. Two patients with hepatocellular carcinoma and three patients with metastases underwent surgical resection 20-60 days after RF treatment. The remaining 32 patients were followed up clinically.

RESULTS

The mean number of RF interstitial thermal ablation sessions to complete tumor nodule treatment was 1.4. Mean number of needle electrode insertions was 1.8. No complications were observed. Posttreatment dynamic CT showed a completely nonenhancing area in the site of the treated tumor in 44 of 45 cases. The remaining patient with metastatic disease had persistent enhancing tissue. Histology showed complete necrosis in four treated tumor nodules and residual viable cancer in one. Twenty-one patients with hepatocellular carcinoma were followed up for 6-19 months (mean, 10 months). Of these patients, six showed recurrences and 15 remained apparently disease-free. Two patients died, one from advanced cancer and one from other causes. Eleven patients with hepatic metastases were followed up for 7-20 months (mean, 12 months). Of these patients, nine showed recurrent disease and only two remained apparently disease-free. Two patients died from disseminated disease.

CONCLUSION

RF interstitial thermal ablation of hepatic tumor by expandable needle electrodes is a safe and effective technique. Local ablation of tumors not exceeding 3.5 cm in diameter is achieved in a short time without complications.

Beyond TPH: health-based evaluation of petroleum hydrocarbon exposures

The term "total petroleum hydrocarbons" (TPH) is a widely used, but loosely defined, parameter quantified by a number of different methodologies for expressing the aggregate amount of petroleum hydrocarbon compounds (PHCs) in a sample. Because of the shortcomings associated with comparing data from different methods, and the difficulty of assessing potential toxicities of complex mixtures of hydrocarbons, a new approach at more fully and explicitly defining the PHC composition of samples and predicting human noncancer health risks from those exposures has been developed. This new approach is the subject of this paper. This method can be used to perform site-specific risk assessments or to develop health-based cleanup standards for petroleum hydrocarbons. The technique divides the broad chemical classes of PHC (i.e., saturated versus unsaturated) into subgroups of compounds based on numbers of carbon atoms in the compounds within each subgroup. The mass of compounds in each subgroup is then translated into discrete estimates of health risk for specified exposure scenarios. The subgroups were identified from qualitative and quantitative changes in the nature of noncancer toxicities recorded in the literature. For saturated compounds, toxicity changes as carbon chain length increases (measured by numbers of carbon atoms). A "reference compound" was chosen for each range of compounds, usually because its toxicity was relatively well characterized. A published oral reference dose (RfD) was identified for these compounds, or in the absence of a published value, an oral dose-response value was developed from available toxicity information. For saturated PHCs (alkanes, cycloalkanes, and isoalkanes) the subgroups' reference compounds and assigned toxicity value used are C5 to C8 (n-hexane, 0.06 mg/kg/day); C9 to C18 (n-nonane, 0.6 mg/kg/day); and C19 to C32 (eicosane, 6.0 mg/kg/day). For unsaturated compounds (aromatics), one reference RfD was identified for all compounds: C9 through C32 (pyrene, 0.03 mg/kg/day). Dependent upon the analytical technique used for separation of compounds, the unsaturated alkenes may be grouped and subsequently quantified with either the saturate or unsaturate groups. The implications of possible association with either group and contributions to risk estimates are probably not significant. Alkenes make up a small fraction of most fuel products, and they bear structural similarity to the alkanes and are not particularly toxicologically active. If grouped analytically with the aromatics the alkene contribution to toxicity estimates would likely be minor and not be an underestimate of its true toxicity. The mass of PHC in each segment of a chromatogram is quantified and converted to a medium-specific concentration which is then entered into standard medium intake equations to arrive at a daily dose of PHC. This dose is then used with the toxicity value identified for the particular segment of the chromatogram to derive a hazard quotient. The quotients can then be summed across fractions to yield a total hazard index. The noncancer health risks from the aromatics benzene, toluene, and xylenes are evaluated separately using standard risk assessment techniques.

A study of gender-based cytochrome P4501A2 variability: a possible mechanism for the male excess of bladder cancer

One hypothesis for the well known gender difference in bladder cancer risk is that males and females metabolize carcinogens differently. The caffeine breath test (CBT) was performed on a group of healthy men and women to determine whether there was a gender difference in P4501A2 activity. Results consistent with previous data suggest an elevation of CBT in men were observed, although this increase was not statistically significant. Among women, however, there was a significant difference between nulliparous and parous women(P = 0.03). Parous women had CBT values similar to men, whereas the results of women who had never given birth were lower. Confirming earlier studies, women taking oral contraceptives had low CBT values. Our data suggest an effect of recent caffeine consumption, with heavy coffee drinkers having higher rates of caffeine clearance. Adjustment for other weak effects, such as age, exposure to environment cigarette smoke, history of smoking, recent meat and cruciferous vegetable consumption, and use of alcohol or other medications, did not alter these findings. The finding of a difference between parous and nulliparous women requires further study.

Hyperthermia increases intercellular adhesion molecule-1 expression and lymphocyte adhesion to endothelial cells

BACKGROUND

We observed that the synergistic combination of immunotherapy and whole-body hyperthermia is active against large well-vascularized tumors but not microscopic tumors, and we therefore hypothesized that hyperthermia may act on lymphocyte-endothelial cell interactions. We undertook these studies to evaluate the effect of hyperthermia on lymphocyte-endothelial cell adhesion.

METHODS

Cultured human umbilical vein endothelial cells (HUVEC) and normal peripheral blood lymphocytes were used. HUVEC were cultured to confluence. Treatment groups included control, hyperthermia alone (41 degrees C for 2 hours), interferon-gamma (IFN-gamma) alone, or hyperthermia + interferon-gamma. 51Cr-labeled peripheral blood lymphocytes were allowed to adhere to treated HUVEC, and nonadhering cells were washed away. Adherent cells were lysed and counted in a gamma-counter, calculating an adhesion index compared to controls. The experiment was then conducted with the addition of anti-intercellular adhesion molecule (ICAM) antibody. Cell surface ICAM expression was determined with double monoclonal antibody staining and fluorescence-activated cell sorter analysis, and soluble ICAM secretion was determined with enzyme-linked immunosorbent assay in each group.

RESULTS

In a representative experiment, interferon-gamma increased adhesion by a factor of 1.81 (p < 0.05) compared with control and hyperthermia by 1.38 (p < 0.05) and combined treatment by a factor of 2.43 (p < 0.05). Anti-ICAM antibody abrogated the increased adhesion caused by hyperthermia but did not abrogate the effect of interferon-gamma. Although only 26% of control cells expressed ICAM-1 on the cell surface, interferon-gamma increased expression to 53% (p < 0.05), hyperthermia increased expression to 38% (p < 0.05), and combined treatment increased expression to 61% (p < 0.05). Soluble ICAM-1 was not increased 12 hours after treatment, but by 24 hours significant (p < 0.05) differences (control 0.262 ng/ml, IFN alone 1.50, hyperthermia alone 1.57, and combined 2.71) were noted.

CONCLUSIONS

These results suggest that hyperthermia has a significant effect on lymphocyte adhesion to endothelial cells, at least in part mediated by ICAM-1. Cell surface ICAM-1 is increased at 12 hours, and soluble ICAM-1 is increased at 24 hours. These data suggest that hyperthermia may function by increasing lymphocyte adhesion, providing another locus of action to improve clinical results with immunotherapy.

A physiological role for cyanate-induced carbonic anhydrase in Escherichia coli

Cyanate induces expression of the cyn operon in Escherichia coli. The cyn operon includes the gene cynS, encoding cyanase, which catalyzes the reaction of cyanate with bicarbonate to give ammonia and carbon dioxide. A carbonic anhydrase activity was recently found to be encoded by the cynT gene, the first gene of the cyn operon; it was proposed that carbonic anhydrase prevents depletion of bicarbonate during cyanate decomposition due to loss of CO2 by diffusion out of the cell (M. B. Guilloton, J. J. Korte, A. F. Lamblin, J. A. Fuchs, and P. M. Anderson, J. Biol. Chem. 267:3731-3734, 1992). The function of the product of the third gene of this operon, cynX, is unknown. In the study reported here, the physiological roles of cynT and cynX were investigated by construction of chromosomal mutants in which each of the three genes was rendered inactive. The delta cynT chromosomal mutant expressed an active cyanase but no active carbonic anhydrase. In contrast to the wild-type strain, the growth of the delta cynT strain was inhibited by cyanate, and the mutant strain was unable to degrade cyanate and therefore could not use cyanate as the sole nitrogen source when grown at a partial CO2 pressures (pCO2) of 0.03% (air). At a high pCO2 (3%), however, the delta cynT strain behaved like the wild-type strain; it was significantly less sensitive to the toxic effects of cyanate and could degrade cyanate and use cyanate as the sole nitrogen source for growth. These results are consistent with the proposed function for carbonic anhydrase. The chromosomal mutant carrying cynS::kan expressed induced carbonic anhydrase activity but no active cyanase. The cynS::kan mutant was found to be much less sensitive to cyanate than the delta cynT mutant at a low pCO2, indicating that bicarbonate depletion due to the reaction of bicarbonate with cyanate catalyzed by cyanase is more deleterious to growth than direct inhibition by cyanate. Mutants carrying a nonfunctional cynX gene (cynX::kan and delta cynT cynX::kan) did not differ from the parental strains with respect to cyanate sensitivity, presence of carbonic anhydrase and cyanase, or degradation of cyanate by whole cells; the physiological role of the cynX product remains unknown.

A comparison of diets of blacks and whites in three areas of the United States

Dietary factors may contribute to the increased cancer risk of blacks. As a first step to explore this hypothesis, we examined food frequency data obtained by interview with 1,976 adults (881 blacks and 1,095 whites) randomly selected from three areas of the United States. The a priori hypothesis was that blacks were more likely to consume diets low in fruits and vegetables and/or high in fat, particularly saturated fat. Contrary to expectation, blacks were more frequent consumers of fruits and vegetables considered to be protective against cancer (e.g., citrus fruits, cruciferous vegetables, and vegetables rich in vitamins A and C). Intake of both total and saturated fat was slightly lower among blacks than whites. This analysis does not rule out a role for these dietary factors in the etiology of cancer but indicates that ascribing the excess cancer risk among blacks to their frequency of fruit and vegetable consumption or intake of fat per se is inadequate. This suggests that alternative dietary explanations for the racial disparity in cancer risk should be pursued in future studies.

Discussing safer sex in HIV counselling: assessing three communication formats

Although it is acknowledged that counselling can be an important factor in behaviour change, we lack information on how HIV counselling works in practice. Research is reported based on transcriptions of audio-tapes of counselling drawn from seven hospital centres in England and the USA. It is shown that communication occurs in the context of three different formats. Certain formats and conversational strategies used by counsellors produce far greater patient participation. Such participation may hold out the prospect of greater behavioural change than simply listening to information and advice.

Exposure to diesel exhaust in the trucking industry and possible relationships with lung cancer

We previously reported that long-term truck drivers and mechanics in the Teamsters Union had higher lung cancer risks than Teamsters outside the trucking industry. We now summarize results from an industrial hygiene survey of current exposures to diesel exhaust in the trucking industry, and relate these to our prior results pertaining to lung cancer risk.

Cancer risk in patients with diabetes mellitus

Cancer incidence was ascertained in a population-based cohort of 51,008 patients in Uppsala, Sweden, who were given a discharge diagnosis of diabetes mellitus during 1965-83. Complete follow-up through 1984 with exclusion of the first year of observation showed that the observed number of cancers in females (1,294) was eight percent higher than expected (relative risk [RR] = 1.1, 95 percent confidence interval = 1.0-1.1), whereas in males the observed number (1,123) was close to the expected (RR = 1.0, 0.9-1.1). Significantly increased risks of pancreatic (RR = 1.4, 1.2-1.7), primary liver (RR = 1.5, 1.2-1.7), and endometrial (RR = 1.5, 1.2-1.8) cancers and a lower than expected number of prostatic cancers (RR = 0.7, 0.7-0.9) were found in this cohort of diabetic patients. The excess risk of pancreatic cancer was similar in females and males and evident both during one through four years (RR = 1.7, 1.4-2.1) and five through nine years (RR = 1.3, 0.9-1.7) of follow-up, but not thereafter. A similar pattern was found for primary liver cancer, but the RRs were generally higher in males than in females.

Production of antibody to and cellular localization of erythrocyte-sensitizing substance from Rickettsia rickettsii

Antibodies to Rickettsia rickettsii erythrocyte-sensitizing substance (ESS) were raised in rabbits by using a derivatized ESS. The resulting antibodies reacted with R. rickettsii and cross-reacted with Rickettsia conorii, a member of the spotted fever group rickettsiae, but did not react with Rickettsia typhi, a member of the typhus group rickettsiae, Legionella bozemanii, or Proteus vulgaris OX19 or OX2. Immunoblot analysis indicated that ESS was present in more than one fraction and that the major haptenic fraction was proteinase resistant. Immunoelectron microscopy indicated that the antibodies to R. rickettsii were specific to components located on the cell surface and intracellularly to components between the cell wall and cytoplasmic membrane.

Changes in rat lung microsomal lipids after p-xylene: relationship to inhibition of benzo[a]pyrene metabolism

The relationship between p-xylene's effects on microsomal membranes, cytochrome P-450, and benzo[a]pyrene (BaP) metabolism was studied. p-Xylene (1 g/kg, ip, 1 h) inhibited 3-hydroxy BaP (3-OH) formation and decreased arylhydrocarbon hydroxylase (AHH) activity approximately 40% in rat lung microsomes. BaP dihydrodiol and quinone formation were unchanged by p-xylene administration. Cytochrome P-450 was below the limit of detection in lung microsomes from p-xylene-treated rats. Total phospholipid (PL) and phosphatidylcholine (PC) in microsomal membranes were decreased 28% and 17%, respectively. Cholesterol (CL), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), and sphingomyelin (SM) were unchanged. The net activity of enzymes involved in the synthesis of PC, phosphatidylethanolamine-N-methyltransferase I and II (PMT I and PMT II), was slightly elevated by p-xylene. PL/CL and PC/PE ratios, indicators of membrane fluidity, were decreased 34% and 13%, respectively, in microsomes from p-xylene-treated rats. Analysis of fluidity by fluorescence polarization showed that the actual fluidity of treated microsomes was slightly decreased (5%) as compared to controls. The decrease in P-450, PL, and PC is considered to contribute to the inhibition of BaP metabolism.

A model for teaching about interdisciplinary practice in health care settings

The authors describe a continuum of collaborative interdisciplinary professional practice which can be used for teaching students in health care settings. Choices about the nature of interdisciplinary practice can be made not only on the imperatives of patient care but also on the interpersonal characteristics of health care providers as well as their needs for professional autonomy. This model can enable students to make clear career decisions about the types of interdisciplinary practice best suited to their interpersonal style and professional needs.

Changing cigarette habits and bladder cancer risk: a case-control study

With the use of data from the 8,764 subjects in the National Bladder Cancer Study, the separate contribution of various aspects of a person's cigarette smoking history to his increased risk of bladder cancer was estimated. These estimates have not been previously available, owing to the smaller sizes of earlier studies. Our data indicated that people who have only smoked unfiltered cigarettes have higher risks than those who have only smoked filtered cigarettes but that people who have switched from unfiltered to filtered have experienced no reduction in risk. Our data also indicated that smoking cessation substantially reduced the risk. The former smoker appeared to benefit both because he stopped adding to the burden of irreversible damage and because he ceased being exposed to some reversible hazard. Thus the former smoker had a lower risk than the current smoker even though they had smoked the same number of cigarettes daily for the same number of years, but the former smoker's risk remained higher than the risk of a person who never smoked. Our data suggest that one-half of the bladder cancer occurring among men in the United States and one-third of that among women is caused by cigarette smoking.