Dioxin congener patterns in commercial catfish from the United States and the indication of mineral clays as the potential source.

Since 1991 the US Department of Agriculture (USDA) has conducted annual surveys of pesticide residues in foods under the Agricultural Marketing Service's Pesticide Data Program (PDP). To assess chemical residues in domestically marketed catfish products, 1479 catfish samples were collected during the 2008-2010 PDPs. A subset of 202 samples was analysed for 17 toxic polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). The average pattern of the individual PCDD/F congener concentrations in the catfish was rather unique in that it had almost no measurable amounts of polychlorinated dibenzofurans (PCDFs), but all PCDDs were present. This pattern was more dominant in the domestically produced catfish products than in the imported products (China/Taiwan). Comparison of the pattern to known sources of PCDD/Fs showed strong similarities to the pattern of PCDD/Fs found in kaolin clays which have often been used as anti-caking agents in animal feeds. To investigate whether catfish feeds may be the source of the PCDD/Fs found in the catfish, archived catfish feed data from a US Food and Drug Administration (USFDA) database were examined. In 61 out of 112 feed samples, the PCDD concentrations were 50 times higher than the PCDF concentrations and resembled the pattern found in the catfish products and in clays mined in the south-eastern United States. Although the source of PCDD/Fs in domestically marketed catfish products cannot be definitively established, mined clay products used in feeds should be considered a likely source and, given the wide concentration range of PCDD/Fs that has been found in clays, a critical control point for PCDD/Fs entrance to the food supply.

Republished paper: assessment of doctors' consultation skills in the paediatric setting: the Paediatric Consultation Assessment Tool.

OBJECTIVE: To determine the utility of a novel Paediatric Consultation Assessment Tool (PCAT). DESIGN: Developed to measure clinicians' communication behaviour with children and their parents/guardian, PCAT was designed according to consensus guidelines and refined at a number of stages. Volunteer clinicians provided videotaped real consultations. Assessors were trained to score communication skills using PCAT, a novel rating scale. SETTING: Eight UK paediatric units. PARTICIPANTS: 19 paediatricians collected video-recorded material; a second cohort of 17 clinicians rated the videos. MAIN OUTCOME MEASURES: Itemised and aggregated scores were analysed (means and 95% confidence intervals) to determine measurement characteristics and relationship to patient, consultation, clinician and assessor attributes; generalisability coefficient of aggregate score; factor analysis of items; comparison of scores between groups of patients, consultations, clinicians and assessors. RESULTS: 188 complete consultations were analysed (median per doctor = 10). 3 videos marked by any trained assessor are needed to reliably (r > 0.8) assess a doctor's triadic consultation skills using PCAT, 4 to assess communication with just children or parents. Performance maps to two factors - "clinical skills" and "communication behaviour"; clinicians score more highly on the former (mean (SD) 95% CI 0.52 (0.075)). There were significant differences in scores for the same skills applied to parent and child, especially between the ages of 2 and 10 years, and for information-sharing rather than relationship building skills (2-tailed significance < 0.001). Conclusions The PCAT appears to be reliable, valid and feasible for the assessment of triadic consultation skills by direct observation.

Assessment of doctors' consultation skills in the paediatric setting: the Paediatric Consultation Assessment Tool.

OBJECTIVE: To determine the utility of a novel Paediatric Consultation Assessment Tool (PCAT). DESIGN: Developed to measure clinicians' communication behaviour with children and their parents/guardian, PCAT was designed according to consensus guidelines and refined at a number of stages. Volunteer clinicians provided videotaped real consultations. Assessors were trained to score communication skills using PCAT, a novel rating scale. SETTING: Eight UK paediatric units. PARTICIPANTS: 19 paediatricians collected video-recorded material; a second cohort of 17 clinicians rated the videos. MAIN OUTCOME MEASURES: Itemised and aggregated scores were analysed (means and 95% confidence intervals) to determine measurement characteristics and relationship to patient, consultation, clinician and assessor attributes; generalisability coefficient of aggregate score; factor analysis of items; comparison of scores between groups of patients, consultations, clinicians and assessors. RESULTS: 188 complete consultations were analysed (median per doctor = 10). 3 videos marked by any trained assessor are needed to reliably (r>0.8) assess a doctor's triadic consultation skills using PCAT, 4 to assess communication with just children or parents. Performance maps to two factors--"clinical skills" and "communication behaviour"; clinicians score more highly on the former (mean (SD) 95% CI 0.52 (0.075)). There were significant differences in scores for the same skills applied to parent and child, especially between the ages of 2 and 10 years, and for information-sharing rather than relationship-building skills (2-tailed significance <0.001). CONCLUSIONS: The PCAT appears to be reliable, valid and feasible for the assessment of triadic consultation skills by direct observation.

Synthesis of potential metabolites of ethyl (E)-4-[2-(3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-yl)-1-propenyl] benzoate.

Potential metabolites of ethyl (E)-4-[2-(3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-yl)-1-propenyl] benzoate were synthesized. The new compounds include ethyl 3-[3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-yl]crotonate, 3-[3,4-dihydro-4,4-dimethyl-1H-1-benzopyran-6-yl]crotonic acid, 3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-carboxylic acid, 4-[3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-yl]delta 2-butenolide, ethyl (E)-4-[3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-yl)-3-hydroxy-1- propenyl]benzoate, ethyl (E)-4-[2-(3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-yl)-2-propenal] benzoate, and ethyl (E)-4-[2-(3,4-dihydro-4,4-dimethyl-2H-1-benzopyran-6-yl)-2-propenoic+ ++ acid]benzoate. Stereospecific oxidizing reagents and/or conditions were developed for these sensitive systems and include the use of SeO2, Clorox bleach, activated MnO2, and NaClO2 in the presence of resorcinol as a chlorine scavenger.

Repeat laparotomy in ovarian carcinoma after primary surgery.

Thirty-two patients with malignant ovarian disease were referred after primary surgery to the Gynaecological Oncology Unit of Groote Schuur Hospital, Cape Town. All 32 patients underwent a re-laparotomy with a view to accurate staging and possible cytoreductive surgery. On referral, 24 patients (75%) had stage I or II disease and the remaining 8 patients (25%) had stage III and IV disease. Twenty-seven patients (81%) had ovarian malignant disease of epithelial origin while the remaining 5 patients (19%) had ovarian disease of nonepithelial origin. Five (20.8%) of a total of 24 patients with stage I or II disease had their disease stage raised after repeat laparotomy. The overall success rate of cytoreductive surgery, i.e. less than 2 cm residual disease, was 58%.

City-size distributions and the world urban system in the twentieth century.

"In this paper we trace and interpret changes in the geographical pattern and city-size distribution of the world's largest cities in the twentieth century. Since 1900 the geographical distribution of these cities has become increasingly dispersed; their city-size distribution by rank was nearly linear in 1900 and 1940, and convex in 1980. We interpret the convex distribution which emerged following World War 2 as reflecting an economically integrated but politically and demographically partitioned global urban system. Our interpretation of changes in size distribution of cities emphasizes demographic considerations, largely neglected in previous investigations, including migration and relative rates of population change."