Simultaneous determination of sulfasalazine and its metabolites sulfapyridine and N-acetylsulfapyridine in human serum by ion-pair high-performance liquid chromatography using a polymer-based column

An HPLC method is described for the simultaneous and rapid determination of sulfasalazine (salicylazosulfapyridine) and two of its metabolites, sulfapyridine and N-acetylsulfapyridine, in human serum. The range of quantitation is 0.1 to 12 micrograms/mL for sulfasalazine and sulfapyridine and 0.25 to 12 micrograms/mL for N-acetylsulfapyridine. Serum is mixed with acetonitrile containing the internal standard sulfamethazine and the ion-pairing agent tetraethylammonium chloride. The acetonitrile extract is concentrated and analyzed by HPLC, using a new polymer-based column, and detected by UV spectroscopy at 270 nm. This paper is the first both to describe the simultaneous analysis of all three of the compounds from serum and to present sulfasalazine concentration-time data following oral administration to humans.     

Positive Thinking Among Slot Machine Gamblers: A Case of Maladaptive Coping?

Background  Research has demonstrated that optimism and “positive illusions” can be used a coping mechanism among those facing adversity. Gamblers are a little studied group who also experience adversity and uncertainty. They often feel considerable levels of frustration, guilt, anger and a sense of feeling cheated after making significant losses. In order to deal with such feelings it is hypothesized that these individuals will search for positive consequences from their behaviour in order to offset this negative affect. Objectives  To (1) determine whether after gambling, gamblers compensate and reduce negative affect by identifying positive consequences from experiencing a loss, and (2) identify types of strategies which gamblers employ and consider how these should be classified. Materials and Methods  Eighty-seven regular slot machine gamblers were interviewed in a variety of environments housing slot machines. Each participant was asked a series of questions in a semi-structured format, to explore possible styles of positive thinking. Results  Nine types of ‘positive thinking’ experienced by gamblers were identified. These included Comparative thinking, Prophylactic thinking, Biased frequency thinking, Responsibility avoidance, Chasing Validation, Prioritization, Resourcefulness, Thoughtfulness, and Fear Reduction. Gamblers who were positive thinkers experienced significantly less guilt than non-positive thinkers. Conclusions  While reduction of negative affect may be perceived as positive in many other contexts, it is argued that it may counteract efforts to promote responsible gambling. Clinical implications and directions for future research are discussed.     

Antenatal diagnosis of a de novo paracentric inversion of chromosome 11

A de novo paracentric inversion of chromosome 11 identified through antenatal diagnosis is described along with long-term follow-up information on the child and discussion of reported experiences with de novo inversions.     

Use of the internet to obtain cancer information among cancer patients at an urban county hospital.

PURPOSE: To evaluate rates, predictors, and barriers to use of the Internet to obtain cancer information among a cohort of cancer patients at an urban county hospital. PATIENTS AND METHODS: Of 208 cancer patients approached, 200 patients completed a structured interview study examining Internet use, perceptions of the accuracy of Internet information, and barriers to use. RESULTS: Only 10% of participants reported using the Internet themselves to obtain cancer information. Another 21% reported exposure to Internet information through proxies. The most common barrier to Internet use cited was lack of Internet access, with 44% reporting that they would use the Internet to obtain cancer information if they had Internet access. Younger age and more years of formal education were significantly associated with Internet use, although race and income were not. Less education, African American race, and female sex were associated with lower estimates of the accuracy of Internet information. Fewer years of formal education was associated with increased likelihood of reporting confusion after reading Internet information. CONCLUSION: Very few cancer patients in this study of a cohort of generally disadvantaged individuals used the Internet themselves to obtain cancer information, although many more desired to do so. Significant opportunities for Web-based interventions aimed at improving cancer care outcomes in this population of cancer patients exist. However, further study will be needed to determine how to make such intervention accessible, trustworthy, and understandable to the disadvantaged.     

The micro gas-liquid chromatographic analysis of 4-(3',3'-dimethylallyl)-1,2-diphenylpyrazolidine-3,5-dione (feprazone) in human biosamples

A gas-liquid chromatographic method for the determination of feprazone in various biological matrixes, employing a choice of detector options, is described. After rapid, micro-scale extraction of the sample with n-butyl acetate at physiological pH, the solution was injected directly onto the chromatograph. Separation was with either an OV7 column and flame ionisation or electron capture detection, or with a carbowax high polymer column and nitrogen specific detection. When 100 mul of plasma was extracted the limit of accurate measurement was 2 mg 1(-1) for F.I.D. and N.P.D. and 0.5 mg 1(-1) with E.C. detection. Quantification was by comparison with a range of plasma calibrators carried throughout the procedure, and determination of peak height ratios against an internal standard incorporated into the extracting solvent. The CV of the assay throughout the concentration range normally encountered in patients undergoing feprazone treatment, ranged between 2.4 and 7.8% for the various detector options. The analytical method has been applied to samples collected both from patients and normal volunteers undergoing treatment with a range of feprazone maintenance doses.     

Arteriovenous glomeruli of the human spinal cord and their possible functional implications

A previous investigation of the radiculomedullary vascular distribution of the human spinal cord showed an immediate filling of the peripheral spinal veins during arterial injections. Because the perfused medium, a mixture of latex and India ink, had a sufficient viscosity to preclude capillary passage, an extensive system of arteriovenous anastomoses (AVA) was indicated. The injection of five additional anatomic cadaver spinal cords was undertaken to specifically determine the intraparenchymal position and structure of these AVA. It was found that only cleared and transilluminated longitudinal parasagittal sections adequately showed that the AVA were formed by an extensive array of intricately coiled arteriovenous glomeruli (AVG) that could pass substantial amounts of blood from third order arterial branches to equivalently sized veins, bypassing the capillary bed. The epithelioid structure of these AVG channel walls, coupled with their highly innervated adventitial tissue indicated a possible functional relationship to similar structures found in the ends (digital pads) of mammalian extremities. Stained serial sections of injected cords showed the vascular relations with nerve fibers derived from the intraspinal parenchyma as well as a possible extraparenchymal autonomic fiber source. The numbers and extent of these AVG complexes suggested they might be involved in the remarkable autoregulation of spinal cord blood flow (SCBF) that is impervious to middle range changes in systemic blood pressure. Future research may more accurately determine the functional role of these previously unreported human spinal AVG, particularly in their possible relation to SCBF autoregulation in normal and injured spines.