Cancer risk due to occupational exposure to polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) demonstrate carcinogenic activity in animal models. Although some epidemiologic studies have implicated PAHs as risk factors for human cancer, the evidence reported to date has not been consistent. The purpose of this report is to describe the associations between occupational exposure to PAHs in the workplace and each of 14 types of cancer. A population-based, case-control study was carried out in Montreal to investigate associations between a large variety of environmental and occupational exposures on the one hand, and several types of cancer on the other. A detailed job history was obtained from each subject along with information on a number of potential confounders. Each job history was reviewed by a team of experts, who used this information to construct a corresponding history of occupational exposures. Among the PAH exposures considered were benzo(a)pyrene (B(a)P) and five categories of PAHs defined on the basis of the source material, namely, wood, petroleum, coal, other sources, and any source. Altogether, 3,730 cancer patients and 533 population controls were interviewed and their job exposure histories coded. For each of 14 types of cancer analyzed, three control groups were available: other cancer patients, population controls, and the pooled set of cancer and population controls. The associations between 14 cancer types and 6 PAH exposures were analyzed using logistic regression methods. For most types of cancer evaluated, there was no evidence of excess risk due to PAHs at the levels encountered in the occupations in which PAH exposure has been prevalent in the Montreal area. For a few cancer sites–the esophagus, the pancreas, and the prostate gland–there were suggestions of excess risk; these observations are noteworthy hypotheses for further investigation. For lung cancer, there appeared to be an increased risk due to PAHs among nonsmokers and light smokers, but not among heavy smokers.     

Cryopreserved cadaveric allografts for treatment of unexcised partial thickness flame burns: clinical experience with 12 patients

Partial thickness burns (PTB) usually heal within 3 weeks. Prevention of infection and desiccation of the wounds are crucial for optimal healing. Early tangential excision of the burn eschar and allografting prevent deepening of the burns, and are therefore advocated for treatment with the best functional and aesthetic results. For superficial partial thickness burns (SPTB) conservative use of topical antimicrobial agents with frequent dressing changes are implemented. We compared the conservarive treatment for PTBs and SPTBs to grafting cryopreserved cadaveric allografts with no prior excision.

Twelve patients with flame PTB areas were allografted after mechanical debridement without excision of the burn wounds. The allografts were cadaveric skin cryopreserved by programmed freezing and stored at −180°C for 30–48 months. Matching burns for depth and area were treated with silver sulfadiazine (SSD) one to two times daily until healing or debridement and grafting were required.

It was found that 80 per cent of the cryopreserved allografts adhered well and 76 per cent of the treated areas healed within 21 days, whereas only 40 per cent of the SSD-treated burns healed within 21 days.

Partial thickness burns can be treated successfully with viable human allografts (cryopreserved cadaveric skin) with no prior surgical excision. The burn wounds heal well within 3 weeks. For deep partial thickness burns (DPTB) treatment with allografts has no advantage if they have not been previously excised.     

Evidence of Increased Class I MHC Expression on Human Peripheral Blood Lymphocytes during Acute Ethanol Intoxication

Certain ethanol-related diseases in humans have been linked to disorders of immunity. Although humoral and cellular immunity have been studied, the precise mechanisms whereby ethanol use leads to tissue damage remain unknown. In order to explore the hypothesis that ethanol may lead to alteration in expression of tissue Class I major histocompatibility antigen causing an autoimmune phenomenon, a population of acutely ethanol-intoxicated patients was studied. Measurement of Class I major histocompatibility antigen on peripheral blood lymphocytes in this population showed a highly significant (p less than 0.01) increase over controls. The role that this increased antigenicity may play in the evolution of clinical disease is discussed.     

Best evidence in critical care medicine Selective digestive decontamination decreases mortality and morbidity in the intensive care

SDD reduces ICU and in-hospital mortality, the length-of-stay in the ICU, the frequency of colonization with resistant GNB, and the total costs of antibiotic treatment. This supports the use of SDD in all patients expected to be on mechanical ventilation for at least two days in ICUs that have low prevalence of VRE and MRSA.     

Is 18F-FDG PET/CT useful for imaging and management of patients with suspected occult recurrence of cancer?

Rising serum tumor markers may be associated with negative imaging in the presence of cancer. CT and (18)F-FDG PET may yield incongruent results in the assessment of tumor recurrence. The present study evaluates the incremental role of (18)F-FDG PET/CT for the diagnosis and management of cancer patients with increasing levels of tumor markers as the sole indicator of potential recurrence after initial successful treatment. METHODS: Thirty-six cancer patients with increasing levels of tumor markers during follow-up and negative CT underwent (18)F-FDG PET/CT, which showed 111 sites of increased tracer uptake. PET/CT was compared with PET results on a site-based analysis for characterization of (18)F-FDG foci and on a patient-based analysis for diagnosis of recurrence. The clinical impact of PET/CT on further patient management was evaluated. RESULTS: Thirty patients (83%) had recurrence in 85 malignant sites (77%). For the site-based analysis, PET had a sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 96%, 50%, 85%, 85%, and 82%, respectively, as compared with the performance indices of PET/CT of 100%, 89%, 97%, 97%, and 100%, respectively. There was a statistically significant difference between the specificity (P < 0.05) and accuracy (P < 0.001) of PET and PET/CT for precise characterization of suspected lesions. For the patient-based analysis, PET had a sensitivity, specificity, and accuracy of 93%, 50%, and 86%, respectively, as compared with PET/CT with values of 93%, 67%, and 89%, respectively (P = not significant). PET/CT was the single modality that directed further management and treatment planning in 12 patients (33%). CONCLUSION: The results of this study indicate that PET/CT may improve the accuracy of occult cancer detection and further lead to management changes in patients with increasing levels of tumor markers as the sole suspicion of recurrent malignancy.     

Haemoglobin at time of referral prior to dialysis predicts survival: an association of haemoglobin with long-term outcomes

Haemoglobin (Hgb) levels are known to be associated with numerousadverse outcomes in both chronic kidney disease (CKD) and non-CKDpatients. This analysis evaluates the association of baseline haemoglobinlevels on survival in CKD patients, who are followed by nephrologists,irrespective of glomerular filtration rate (GFR), prior to initiationof renal replacement therapy (RRT) and erythropoietin hormonereplacement therapy. Analysis of data from the provincial database (PROMIS, PatientRegistration and Outcome Management Information System) in BritishColumbia, Canada, was undertaken. Records used for the analysisincluded all CKD patients at first registration: GFR <60ml/min/1.73 m², not yet on dialysis, starting from May 1998to October 2002, and who had complete data (defined as age andgender, diabetic status, eGFR and Hgb levels). The primary objective of this study was to determine the associationof Hgb and survival controlling for eGFR at first registrationvalue, age, gender and diabetic status. Multivariate Cox proportionalhazards analysis with time to death as outcome variable wasperformed. The cohort included 3028 patients: the mean age was 65 years,28% were diabetic, and the mean eGFR in the cohort was 21 ml/min/1.73m². The cohort is representative of the BC CKD and dialysispopulation regarding ethnicity: 64% Caucasian, 32% Asian. Medianfollow-up was 27 months, 1 year survival was 0.92, 2 year survivalwas 0.85. Hgb at initial registration is a statistically independentpredictor of survival (RR = 0.875 for every 10 g/l, 95% CI:0.835–0.917, P = 0.0001), after adjusting for age, gender,diabetic status and baseline eGFR. Further analysis, controllingfor RRT, demonstrated a similar association between Hgb andsurvival (RR = 0.853 for every 10 g/l, 95% CI: 0.799–0.910,P = 0.0001), after adjusting for above variables. Substantialvariation in Hgb values exists at all GFR levels. These findings underscore the importance of evaluating Hgb atall GFR levels, and the need to study the impact of modificationof Hgb at different GFR levels on survival.     

User satisfaction with a real-time automated feedback system for general practitioners: a quantitative and qualitative study.

OBJECTIVE: The GRIF automated feedback system produces real-time comments on the appropriateness of diagnostic tests ordered by general practitioners (GPs) based on recommendations from accepted national and regional practice guidelines. We investigated the experiences of GPs with this system and, more specifically, with the recommendations produced by the system as well as their views on using this system in daily practice. SETTING: We tested the GRIF system in an experiment in a laboratory setting and in a daily practice trial. STUDY PARTICIPANTS: General practitioners. INTERVENTION: In the laboratory experiment, GPs used the GRIF system to assess the appropriateness of 30 request forms. Each of the GPs was confronted with requests they had submitted to the diagnostic unit of the hospital in the past. In the field trial, the GRIF system was applied during patient consultations for 1 year. MAIN OUTCOME MEASURES: We measured GPs' satisfaction with the system using a questionnaire, and also conducted group discussions (in the laboratory experiment) and in-depth interviews (in the field trial) to elicit GPs' opinions of and experiences with the system. In addition, we explored GPs' reasons for not accepting the comments offered by the GRIF system. RESULTS: The results show that the GPs in the laboratory experiment had more positive attitudes towards the system compared with participants in the field trial. All discussion groups and most of the GPs in the field trial regarded receiving the immediate feedback during the test ordering process as an important advantage. The most frequently mentioned reason to reject the recommendation was disagreement with the content and/or the recommendations in the practice guidelines. CONCLUSION: Apart from securing agreement on guideline content, a prerequisite for using GRIF in daily practice on a large scale is that more attention is paid to promotion of the guidelines and their adoption, and stimulation of a positive attitude towards the practice guidelines among the users.