The epigenetic effects of assisted reproductive technologies: ethical considerations.

The use of assisted reproductive technologies (ART) has increased significantly, allowing many coping with infertility to conceive. However, an emerging body of evidence suggests that ART could carry epigenetic risks for those conceived through the use of these technologies. In accordance with the Developmental Origins of Health and Disease hypothesis, ART could increase the risk of developing late-onset diseases through epigenetic mechanisms, as superovulation, fertilization methods and embryo culture could impair the embryo's epigenetic reprogramming. Such epigenetic risks raise ethical issues for all stakeholders: prospective parents and children, health professionals and society. This paper focuses on ethical issues raised by the consideration of these risks when using ART. We apply two key ethical principles of North American bioethics (respect for autonomy and non-maleficence) and suggest that an ethical tension may emerge from conflicting duties to promote the reproductive autonomy of prospective parents on one hand, and to minimize risks to prospective children on the other. We argue that this tension is inherent to the entire enterprise of ART and thus cannot be addressed by individual clinicians in individual cases. We also consider the implications of the 'non-identity problem' in this context. We call for additional research that would allow a more robust evidence base for policy. We also call upon professional societies to provide clinicians with guidelines and educational resources to facilitate the communication of epigenetic risks associated with ART to patients, taking into consideration the challenges of communicating risk information whose validity is still uncertain.

Food web structure in oil sands reclaimed wetlands.

Boreal wetlands play an important role in global carbon balance. However, their ecosystem function is threatened by direct anthropogenic disturbance and climate change. Oil sands surface mining in the boreal regions of Western Canada denudes tracts of land of organic materials, leaves large areas in need of reclamation, and generates considerable quantities of extraction process-affected materials. Knowledge and validation of reclamation techniques that lead to self-sustaining wetlands has lagged behind development of protocols for reclaiming terrestrial systems. It is important to know whether wetlands reclaimed with oil sands process materials can be restored to levels equivalent to their original ecosystem function. We approached this question by assessing carbon flows and food web structure in naturally formed and oil sands-affected wetlands constructed in 1970-2004 in the postmining landscape. We evaluated whether a prescribed reclamation strategy, involving organic matter amendment, accelerated reclaimed wetland development, leading to wetlands that were more similar to their natural marsh counterparts than wetlands that were not supplemented with organic matter. We measured compartment standing stocks for bacterioplankton, microbial biofilm, macrophytes, detritus, and zoobenthos; concentrations of dissolved organic carbon and residual naphthenic acids; and microbial production, gas fluxes, and aquatic-terrestrial exports (i.e., aquatic insect emergence). The total biomass of several biotic compartments differed significantly between oil sands and reference wetlands. Submerged macrophyte biomass, macroinvertebrate trophic diversity, and predator biomass and richness were lower in oil sands-affected wetlands than in reference wetlands. There was insufficient evidence to conclude that wetland age and wetland amendment with peat-mineral mix mitigate effects of oil sands waste materials on the fully aquatic biota. Although high variability was observed within most compartments, our data show that 20-year-old wetlands containing oil sands material have not yet reached the same level of function as their reference counterparts.

Vascular and extravascular complications of liver transplantation: comprehensive evaluation with three-dimensional contrast-enhanced volumetric MR imaging and MR cholangiopancreatography.

OBJECTIVE: Our purpose was to evaluate a comprehensive MR imaging strategy for recipients of liver transplants that relies on dynamic interpolated three-dimensional (3D) MR imaging for simultaneous vascular, parenchymal, and extrahepatic imaging. MATERIALS AND METHODS: Twenty-three consecutive adult patients underwent 30 MR imaging examinations between 2 days and 99 months (mean, 15 months) after transplantation using a breath-hold 3D gradient-echo sequence (TR range/TE range, 3.7-4.7/1.8-1.9; flip angle, 12-30 degrees ) with an intermittent fat-saturation pulse and interpolation in the section-select direction to enable pixel size 3 mm or less in all dimensions. Unenhanced and triphasic contrast-enhanced 3D imaging (average dose, 0.13 mmol/kg of gadopentetate dimeglumine) was performed. A subset of patients (n = 13) also underwent MR cholangiopancreatography using half-Fourier single-shot turbo spin-echo imaging. MR imaging examinations were correlated with digital subtraction angiography (n = 8), contrast-enhanced cholangiography (n = 9), sonography (n = 13), and histopathology (n = 14). RESULTS: MR imaging revealed abnormal findings in 27 (90%) of 30 examinations, including vascular disease in nine, biliary complications in four, and evidence of intra- or extra-hepatic hepatocellular carcinoma recurrence in six. Digital subtraction angiography confirmed seven MR angiography examinations but suggested disease overestimation in one. Contrast-enhanced cholangiography confirmed findings of MR cholangiopancreatography in seven cases but suggested disease underestimation in two. CONCLUSION: Dynamic interpolated 3D MR imaging combined with dedicated MR cholangiopancreatography can provide a comprehensive assessment of vascular, biliary, parenchymal, and extrahepatic complications in most recipients of liver transplants.

Does the Centers for Disease Control's NNIS system risk index stratify patients undergoing cardiothoracic operations by their risk of surgical-site infection?

BACKGROUND: In 1991, the Centers for Disease Control and Prevention devised the National Nosocomial Infection Surveillance (NNIS) System risk index to stratify populations of surgical patients by the risk of acquiring surgical-site infections (SSIs). OBJECTIVE: To determine whether the NNIS risk index adequately stratifies a population of cardiothoracic surgery patients by the risk of developing SSI. DESIGN: Case-control study. SETTING: The University of Iowa Hospitals and Clinics, a 900-bed, midwestern, tertiary-care hospital. PATIENTS: 201 patients with SSIs identified by prospective infection control surveillance and 398 controls matched by age, gender, type of procedure, and date of procedure. All patients underwent cardiothoracic operative procedures between November 1990 and January 1994. RESULTS: The SSI rate was 7.8%. Seventy-four percent of cases and 80% of controls had a NNIS risk index score of 1; 24% of cases and 16% of controls had a score of 2 (P=.05). Patients with a NNIS risk score > or =2 were 1.8 times more likely to develop an SSI than those with a NNIS score <2 (odds ratio, 1.83; 95% confidence interval, 1.14-2.94, P=.01). The duration of the procedure was the only component of the index that stratified the population by risk of SSI. CONCLUSIONS: The risk of SSI after cardiothoracic operations increases as the NNIS risk index score increases. However, this index only dichotomized the patient population on the basis of the procedure duration. More research is needed to develop a risk index that adequately stratifies the risk of SSI after cardiothoracic operations.

Atypical presentation of dissection of the ascending aorta in young men with cystic medial necrosis: MR findings.

Dissection of the ascending aorta is usually associated with severe chest and/or back pain. We describe three young men, with pathologically proven cystic medial necrosis, who presented with atypical clinical symptoms and ascending aortic dissection diagnosed by MR imaging and surgery. Patients with cystic medial necrosis and aortic dissection may not present with a classic acute chest pain syndrome.

From a unidimensional to a bidimensional concept and measurement of workers' safety behavior.

OBJECTIVES: This study examines the concept and measurement of worker's safety behavior. It shows that the traditional concept of safety behavior centered on workers' carefulness or compliance with safety rules is limited and proposes that an additional dimension, namely, workers' safety initiatives, be taken into account. METHODS: Confirmatory factor analyses were carried out for a random sample of 828 workers drawn from 9 manufacturing facilities located in the province of Quebec (Canada). RESULTS: A 2-correlated congeneric factor model gave parameters in the expected direction, but the overall model was unable to reach a good fit. Separate construct analyses showed that compliance with safety rules is not a consistent dimension. The safety-initiatives dimension achieved a good fit with a high composite reliability (p=0.85). CONCLUSIONS: Workers' compliance with safety rules was not structured as a unitary dimension; therefore a selective process of safety-rules compliance by workers is suggested. Each category of safety rules should be considered as 1 single dimension and measured by several specific indicators. Indicators for safety initiatives provide high reliability, and, since this dimension is an important predictor of effectiveness in accident prevention, the items tested provide a better measurement than those previously published.

Detection of renal artery stenosis with Doppler sonography before and after administration of captopril: value of early systolic rise.

OBJECTIVE: The goal of this study was to assess the value of quantitative and qualitative analysis of the early systolic rise on Doppler waveforms obtained before and after administration of captopril in patients suspected of having renal artery stenosis. SUBJECTS AND METHODS: Seventy-one hypertensive patients (135 kidneys) were studied with transrenal Doppler sonography. Ninety-six kidneys were studied again after administration of captopril. All patients also underwent renal angiography. All Doppler studies were independently reviewed by two observers. Specific criteria for Doppler waveform patterns that were applied in the detection of renal artery stenosis included acceleration, acceleration time of early systolic rise, differential velocity of systolic rise, and resistive index. These criteria were then correlated with angiography, and receiver operating characteristic curves were generated. RESULTS: On the basis of waveform pattern recognition. Doppler sonograms obtained before administration of captopril had a sensitivity of 81% and a specificity of 98% for the detection of renal artery stenosis greater than or equal to 50%. Sensitivity of Doppler sonography obtained after administration of captopril was 100%, and specificity was 100%. For renal artery stenosis greater than or equal to 70%, sensitivity was 94% and specificity was 89% before administration of captopril. The area under the receiver operating characteristic curve for the acceleration criterion was significantly larger after administration of captopril (p = .009) for the detection of renal artery stenosis greater than or equal to 50%. After captopril administration, an acceleration threshold value of 440 cm/sec2 for early systolic rise was associated with a sensitivity of 100% and a specificity of 94% for the detection of renal artery stenosis greater than or equal to 50%. CONCLUSION: Doppler sonography of the renal arteries performed before administration of captopril appears to be an excellent screening tool in the detection of severe stenosis (> or = 70%). Administration of captopril improves the detection of renal artery stenosis greater than or equal to 50% with Doppler sonography when observers use both morphologic and quantitative criteria.

Basics of surgical-site infection surveillance.

Surgical-site infections, the third most common class of nosocomial infections, cause substantial morbidity and mortality and increase hospital costs. Surveillance programs can lead to reductions in surgical-site infection rates of 35% to 50%. Herein, we will discuss the practical aspects of implementing a hospital-based surveillance program for surgical-site infections. We will review surveillance methods, patient populations that should be screened, and interventions that could reduce infection rates.

The cost-effectiveness of preventing tuberculosis in physicians using tuberculin skin testing or a hypothetical vaccine.

BACKGROUND: Tuberculin skin testing using the purified protein derivative is recommended as part of a tuberculosis control program for health care workers. However, compliance with skin testing programs has been poor and their cost-effectiveness is unknown. METHODS: A Markov-based decision analysis was performed to determine the cost-effectiveness of tuberculin skin testing over the entire lifetimes of physicians who are now in medical school. Assumptions were deliberately chosen to present a conservative estimate of cost-effectiveness. Indirect costs were not included. RESULTS: Annual testing cost $29,000 per life-year saved and $39,000 per case of pulmonary tuberculosis prevented. In contrast, particulate respirators have been shown to cost millions of dollars per case prevented. Skin testing every 6 months was cost-effective in a subpopulation at high risk of infection (> or = 1.8-fold). During their entire lifetimes, physicians now in medical school can expect to avert 137 cases of pulmonary tuberculosis, prevent 7 tuberculosis deaths, and save 182 life-years because of skin testing programs. Improved compliance with annual skin testing and prophylactic isoniazid could more than triple this benefit. If available, a moderately effective vaccine would be even more cost-effective than tuberculin skin testing programs. CONCLUSIONS: Tuberculin skin testing is cost-effective and should be an integral part of any tuberculosis control program. Vaccination may one day be a feasible and cost-effective alternative to skin testing programs.

Correlation between frequency of tuberculosis and compliance with control strategies.

OBJECTIVE: To determine if compliance with annual tuberculosis skin testing correlated with the number of cases of tuberculosis seen in patients and healthcare workers. DESIGN: Survey using a written questionnaire. SETTING AND PARTICIPANTS: 159 Veterans' Administration facilities. RESULTS: Hospitals that reported that > 80% of their healthcare workers received annual skin tests saw 12.7 patient cases per 10,000 admissions and 4.0 healthcare worker cases per 10,000 personnel. Facilities in which < 20% of their healthcare workers were given annual skin tests saw 4.5 cases per 10,000 admissions and 1.6 cases in healthcare workers per 10,000 personnel (P < .001 for patients and P = .31 for healthcare workers). The ratio of the median number of patients placed in acid-fast bacilli (AFB) isolation to the median number of patients with confirmed tuberculosis was 12. There was no correlation of this ratio with the number of cases of tuberculosis in patients or healthcare workers seen in each facility. CONCLUSION: Compliance with annual tuberculosis skin testing was related directly to the rate of tuberculosis seen in patients. More standardized policies for placing patients in AFB isolation are needed to control for potentially costly variation among facilities. These measures should have highest priority in the control of tuberculosis in the healthcare setting, before implementing still more expensive interventions.

Postoperative wound infections: risk factors and role of Staphylococcus aureus nasal carriage.

In the United States the rate of postoperative wound infection varies from one to nine per cent, depending on the surgical procedure. Each postoperative wound infection increases the length of stay in hospital, the cost of the procedure and is associated with significant morbidity. Staphylococcus aureus is the causative agent in 15 to 20% of these infections, although the pathogen isolated varies according to the surgical site. Risk factors for acquiring an infection can be divided into the following categories: host factors, surgical and environmental factors, and microbial characteristics. Host factors which may contribute to an increased risk of infection include: age, prolonged pre-operative length of stay, and concurrent infection at another body site. Increased infection risk may result from an extended surgical procedure, the wound classification, the use of a razor for hair removal before surgery and may also be dependent on the surgeon's technical skill. Microbial factors related to the risk of developing an infection postoperatively are less well defined, however, many outbreaks of surgical wound infections have been linked to personnel carrying an organism which is then transmitted to the patient. Furthermore, patients who carry intranasal S. aureus have a two-to ten-fold increased likelihood of developing a postoperative wound infection due to S. aureus. Identification of patients most at risk of developing an infection is the ultimate goal, however, risk indices must be highly sensitive, specific and accurate. To summarize, the epidemiology of postoperative wound infections remains poorly studied, however, since wound infections contribute significantly to morbidity, mortality and cost, future research is warranted.

[Social anomie and the renewed increase of mental health problems at the work place]. / Anomie sociale et recrudescence des problèmes de santé mentale au travail.

Several studies on mental health in the workplace show a renewed increase of mental health problems. These problems, related to workplace relations, present social causes of a much larger degree; for instance, the social anomy afflicting Québec is rippling through the workplace, much like what many other industrialized societies are experiencing during this end of century. The sensitive social balance, in principle under the responsibility of social institutions and government, has given business the opportunity to occupy a central position and become the major forum for an individual's search for identity. This centrality carries with it a certain number of strong contradictions and disappointments because, in spite of the rhetoric and its illusions, corporations are loyal to economic logic and take a perverse ownership of one of the individual's most important values, namely the quest and desire to be defined as a person and to be acknowledged as such. As a result, individuals often find themselves in a fragile state, at times even left with deconstructed psyches.