Evaluation of a fluorometric screening method for predicting total PAH concentrations in contaminated sediments.

A fluorometric screening method was used to estimate total polycyclic aromatic hydrocarbon (t-PAH) concentrations in sediments collected from the St. Louis River Area of Concern (AOC) in northeastern Minnesota. Sediments were collected as part of a Regional Environmental Monitoring and Assessment Program (R-EMAP) study to assess sediment quality in the AOC. The screening method was calibrated using a PAH surrogate standard consisting of eight PAHs commonly found in the St. Louis River system, at their approximate proportions. Estimated PAH concentrations were compared to GC/MS measured 'true' PAH concentrations to evaluate the overall predictive power of the screening method. Regression analysis of log transformed estimated versus true PAH concentration yielded an r2 of 0.72 (n = 86). In addition, the rates of false positive and false negative predictions associated with the screening method were determined relative to different sediment effects concentrations (SECs) for total PAHs. In general, the rate of false positive predictions was shown to increase as the SEC criteria value decreased, while false negative rates remained consistently low (below 7%). Methodological recommendations which led to a three-fold reduction in false negatives, and the improved prediction of both high and low PAH samples, are presented.

Piperonyl butoxide as a tool in aquatic toxicological research with organophosphate insecticides.

Experiments were conducted to determine the effects of piperonyl butoxide, a synthetic methylenedioxyphenyl inhibitor of cytochrome(s) P450, on the toxicity of organophosphate insecticides to three cladoceran test species: Ceriodaphnia dubia. Daphnia magna, and Daphnia pulex. Coadministration of piperonyl butoxide effectively reduced the acute toxicity of four metabolically activated organophosphates (parathion, methyl parathion, diazinon, and malathion) and did not affect the toxicity of three organophosphates not requiring metabolic activation (dichlorvos, chlorfenvinphos, and mevinphos). These results indicate that piperonyl butoxide may be an effective tool in toxicological research focused upon identifying specific compounds responsible for toxicity in complex aqueous mixtures.

Organizational and community approaches to community-wide prevention of heart disease: the first two years of the Pawtucket Heart Health Program.

The Pawtucket Heart Health program (PHHP) is a federally funded research and demonstration project for the primary prevention of coronary heart disease (CHD) in a community. This article presents a discussion of the first 26 months of this intervention, divided into its three phases. PHHP staff initially approached the intervention city through local organizations to accomplish risk-factor behavior change in the population. After 11 months, PHHP complemented its programs in organizations with activities open to all city residents, in order to accelerate participation by the population. Seven months into this phase, it was decided that community activities should be the major focus of the intervention approach to assure a level of participation adequate to make a measurable impact. The third has shown the greatest percentage of public participation, demonstrating the complementary nature of organization and community interventions and of the translation of social learning theory into principles for primary prevention in a community.

Community intervention to lower blood cholesterol: the "Know Your Cholesterol" campaign in Pawtucket, Rhode Island.

Sufficient data exist to support approaches to lowering cardiovascular disease risk which target population-wide reductions in elevated blood cholesterol levels. Within the context of a multifactorial cardiovascular disease prevention program, a 2-month cholesterol education campaign was launched to encourage citizens to "Know Your Cholesterol" by attending screening, counseling, and referral events (SCOREs) held throughout the community. These events featured assessment of dietary fat and cholesterol, rapid blood cholesterol analyses with a fingerstick procedure and the Kodak Ektachem DT60, and immediate dietary counseling by trained volunteers. A total of 1439 persons attended 39 SCOREs: nearly 60% were found to have blood cholesterol levels that exceeded recommended goal levels. At a 2-month follow-up of 1040 of these same individuals, 600 had lowered their blood cholesterol level by an average of 29.1 mg/dl. This experience suggests that similarly modeled campaigns may have a significant impact on the distribution of blood cholesterol levels in the entire U.S. population.

Plasma fibronectin in medical ICU patients.

Plasma fibronectin levels in 66 medical ICU (MICU) patients were measured daily. Mean values of initial levels were significantly higher in survivors (266 +/- 14 mg/L) than nonsurvivors (179 +/- 13 mg/L; p less than .0003). There was extensive overlap between survivors and nonsurvivors. The clinical categories of sepsis, disseminated intravascular coagulation (DIC), adult respiratory distress syndrome (ARDS), and hepatic failure with GI bleeding were associated with low fibronectin levels. Within all diagnostic categories the mean initial fibronectin level of the survivors was higher than that of nonsurvivors. This difference was significant only in the septic group (p less than .02). Patients with minimum fibronectin levels less than 195 mg/L had a 65% mortality rate; patients with minimum levels greater than or equal to 195 mg/L had a 17% mortality rate. Fibronectin, via its role in reticuloendothelial system (RES) function, may have a pathophysiologic role in a variety of medical illnesses.

Abdominal pain, atherosclerosis, and atrial fibrillation. The case for mesenteric ischemia.

DT, a 63-year-old white male with insulin-dependent diabetes mellitus and severe peripheral vascular disease, was admitted with a five-day history of vague abdominal pain and diarrhea. On the day of admission he vomited three times, was noted to have a bloody stool, and came to the emergency room. DT denied hematemesis, fever, or chills. He had bilateral leg amputations and had sustained three myocardial infarctions, the last one 15 months before this admission. He had never experienced symptoms of abdominal angina. Of significance was his history of congestive heart failure, mitral regurgitation, and atrial fibrillation. His medications on admission included digoxin 0.25mg per day, furosemide 40mg per day, and NPH insulin 15 units per day. On admission to the hospital his oral temperature was 38 degrees C, pulse was 90/min, respiratory rate was 24/min, and blood pressure was 134/80mmHg. Abdominal examination revealed a distended abdomen with hypoactive bowel sounds and mild tenderness. Chest x ray revealed cardiomegaly. The electrocardiogram demonstrated atrial fibrillation. A plain film of the abdomen was positive for gallstones and edema of the bowel wall (thumb-printing). Laboratory results included blood urea nitrogen 48mg%, creatinine 1.2mg%, hemoglobin 18g/dl, and hematocrit 52.9%. White blood cell count was 11,900 cells/cc with 33% polymorphonuclear leukocytes, 47% bands, 8% lymphocytes, 11% monocytes, and 1% atypical lymphocytes. The prime considerations for differential diagnosis were mesenteric ischemia and infectious gastroenteritis. While it was appreciated that mesenteric ischemia, if present, might warrant surgical intervention, the risk of anesthesia itself in this patient was felt by his attending physicians to exceed 30%. Furthermore, the clinical findings were only "suggestive" of mesenteric eschemia. They were certainly not "diagnostic." In view of this dilemma, a consultation with the Division of Clinical Decision Making was requested.

A model for the structure of bovine parathormone derived by dark field electron microsocpy.

We have analyzed images of parathormone obtained by dark field electron microscopy in order to determine the three-dimensional structure of the molecule. The technique of autocorrelation was used to differentiate hormone particles from the background of noise in the electron micrographs. Our data suggest that parathormone is about 36 A in maximum dimension and is comprised of two interconnected domains of different mass that occur in a consistent orientation to each other. By means of the formulation of Chou and Fasman (Chou, P.Y., and Fasman, G.D. (1974) Biochemistry 13, 211-222), we predicted the secondary structure of the hormone and fitted this into the three-dimensional structure developed by microscopy. The resultant speculative model can explain certain physical and chemical properties of parathormone.