Residues of PCB's and DDT in the western Lake Superior ecosystem

Fish from western Lake Superior (1972–73) contained DDT and PCB residues at concentrations greater than 0.1 ppm. The most predominant PCB's were those containing 3 to 6 chlorine atoms per molecule, and GLC data indicated that the mixtures were most like the commercial product Aroclor^® 1254. Other chlorinated contaminants identified by GC/MS analyses and occurring at concentrations less than 0.1 ppm were hexachlorobenzene (C₆Cl₆), chlordane, nonaclor, and dieldrin. Lindane, which has been previously reported in Lake Superior, was below the detection limit of approximately 0.01 ppm.The relationship between the size of lake trout and the concentration of total DDT in the fish was compared to measurements reported in previous studies. The comparison suggests that DDT residues have declined since 1968. The concentration of PCBs was estimated to be 0.8 ng/L in Lake Superior water and 0.1 ppm in large zooplankton. The apparent bioconcentration factor for PCBs in Lake Superior fish ranged from 10⁵ to 10⁶. The concentration of total DDT and PCBs in the larger Lake Superior fish exceeded the 5 ppm tolerance level established by the U.S. Food and Drug Administration for these chemicals in fish to be used for human consumption.     

Promoting Healthy Lifestyles: Alternative Models' Effects (PHLAME)

The Promoting Healthy Lifestyles: Alternative Models' Effects (PHLAME) study evaluates the efficacy of two intervention strategies for improving nutrition and physical activity practices in fire fighters: a team-centered program and a one-on-one format targeting the individual. PHLAME compares these two behavior change models (the team-based versus the one-on-one approaches) against a usual-care control group. As a group, fire fighters have a concentration of the same harmful behaviors and health risks commonly afflicting the US population. Fire fighters have a unique work structure which is ideal for a team-centered model of behavior change. This strategy, based on Social Learning Theory, focuses on a team of fire fighters who work together on the same shift. If this team-centered model proves successful, it could provide a cost-effective method to impact behavior, and be disseminated among fire bureaus and in other team settings. The one-on-one intervention incorporates the Transtheoretical Model of behavior change, uses Motivational Interviewing for its counseling strategy and could be used in the more typical provider-client clinic setting. Findings from PHLAME will provide information about the process and outcomes of these models' ability to achieve health behavior change.     

Limited posterior thoracotomy for the correction of intra cardiac anomalies–current perspectives

Background Though the use of median stermotomy has been fairly standardized for the approach to the heart and great vessels, since the advent of cosmetically appealing incisions, thoracotomy has come to be a justifiable alternative incision. This paper presents our experience with this approach and the advantages over the conventional approach as well as over other incisions for the correction of intra-cardiac anomalies. Methods 93 patients underwent open cardiac procedures using the posterior thoracotomy approach since June 1997 to December 2000. There were 69 patients with ostium secundum atrial septal defects and 12 patients with sinus venous defects. Other anomalies included perimembranous ventricular septal defects in 3 patients, partial atrioventricular septal defects in 3 patients and transitional atrioventricular septal defects in 2 patients. Besides these, one patient each underwent atrial septectomy with right modified Blaloc—Taussing shunt and correction of hemianomalous pulmonary venous connection with intact atrial septum using this approach. The median age of the patients was 8 years with a range of 10 months to 41 years. 10 patients were males. Results The median operation time (skin to skin) was 236 minutes. Median bypass times and aortic cross clamp times were 63 minutes and 31.5 minutes respectively. The median ICU stay was 25.2 hours. There were no significant immediate post operative complications requiring intervention in any patient. The mean chest drainage was 80 ml per 24 hours. One patient had a superficial wound dehiscence which healed with daily dressings One patient had atelectasis of the right upper lobe which recovered with chest physiotherapy. All patients are on regular follow up to assess the status of their scars. One patients developed a mass on the right atrial free wall following closure of atrial septal defect one year earlier and the underwent reoperation for removal of the mass. Patients on follow up were interrogated and all were satisfied with the cosmesis of their scars. None of the patients had any physical disability due to their scars. Conclusions The limited posterior thoracotomy incision offers a cosmetically attractive approach to the heart in selected patients. The approach is easy and the techniques reproducible. The technique carries with it no additional risk and has the advantage of not interfering with future development of the breast in young pre pubertal girls.     

Acute coronary syndromes

The first 150 words of the full text of this article appear below. Key points Coronary artery disease accounts for >30% ofdeaths in Western society. The diagnosis of myocardial infarctionshould be qualified by size, causation and time from occurrence. Mortalityis reduced by immediate or ‘primary’ percutaneouscoronary intervention or thrombolysis within the first 24 hof onset of ST-segment elevation myocardial infarction. Strategiesto reduce platelet activation (glycoprotein IIb/IIIa receptorantagonists, or clopidogrel) are now recommended in the treatmentof high-risk non-ST-segment myocardial infarction/unstable angina. Elevatedserum troponins may be the result of non-ischaemic myocardialdamage, especially in critical illness.