Application of solid phase microextraction to the determination of strychnine in blood.

A simple and rapid method based on solid phase microextraction (SPME) via direct immersion followed by gas chromatography coupled with electron impact ionization/mass spectrometry (GC/EI-MS) was developed for the determination of strychnine in blood. Papaverine was used as internal standard (I.S.). Two types of fibre coating were tested, 100 microm polydimethylsiloxane and 65 microm Carbowax/Divinylbenzene, the latter giving higher recoveries of the compound. The main factors affecting the SPME process, such as sample dilution (1:10), adsorption and desorption times (20 and 10 min, respectively), carry-over effect (not observed), pH and salt addition (no modifications on pH or salt concentration) were optimized. The procedure was validated in terms of linearity (r(2)=0.9992 for concentrations ranging from 0.10 to 5.00 microg/mL), intra and interday precision (0.93 and 4.62%, respectively at 0.50 microg/mL; 3.33 and 8.06%, respectively at 2.50 microg/mL), sensitivity (6.83 and 8.91 ng/mL for LOD and LOQ, respectively) and extraction recovery (0.54 and 0.39% at 0.50 and 2.50 microg/mL, respectively). The developed procedure was found suitable for forensic investigations and was considered a good alternative to the liquid-liquid extraction methods normally used for the determination of this compound in biological media.

Training in medical informatics: combining onsite and online instruction.

The Internet is promoting active exchange of teaching materials and discussion among geographically distant collaborators. We envision that training in medical informatics can be better achieved if both onsite and online instruction are combined, provided that cultural and technological barriers are anticipated and the training program is prepared accordingly. We describe our Brazil/USA program in medical informatics, which includes components of on-site and online education, and discuss lessons learned during its ongoing implementation. Three onsite courses and one workshop have been planned, and two online courses are being developed.

Analytical method for the determination of strychnine in tissues by gas chromatography/mass spectrometry: two case reports.

This paper describes an analytical method for strychnine determination in biological samples by gas chromatography/mass spectrometry and their application in the investigation of two cases involving strychnine ingestion: A fatal case and a clinical one. The strychnine is isolated from biological samples using a liquid-liquid extraction procedure. The clean-up procedure is performed using an acid solution. Papaverine is used as internal standard in the quantification of strychnine. In the analysed specimens, the limits of quantification were 0.1 microg/ml or 0.1 microg/g. The recovery rate ranged from 75.0% to 98.7% and the coefficients of variation ranged from 4.8% to 10.5%.

[Progression to IDDM and islet cell antibodies (ICA; ICA-CF)]. / Estudo de auto-anticorpos para ilhotas pancreáticas (ICA e ICA-CF) e evolução para o diabetes insulino-dependente (DM ID).

We have followed eight first-degree relatives of IDDM patients (insulin-dependent, type I diabetes) attending the outpatient diabetes clinic at the State University of Rio de Janeiro for three years, all of them with positive islet cell antibodies (ICA and/or ICA-CF). Three out of eight relatives less than fifteen years old have subsequently progressed to overt Insulin-Dependent Diabetes Mellitus (IDDM) 12, 21 and 8 months after the first positive autoantibodies detection. Four relatives have remained with ICA and/or ICA-CF positive, and in another one the reaction became negative during the observation period. A positive correlation has been found between high titles of ICA (> or = 1/16) and development of IDDM. We have concluded from our prospective study during three years that of our antibody-positive relatives, 37.5 % have developed overt diabetes, all of them being less than fifteen years old, with high titles of ICA and ICA-CF positive.

Prevalence of autoantibodies in simplex and multiplex families of Brazilian insulin-dependent diabetic patients.

1. Forty-one simplex and 6 multiplex families of Brazilian IDDM patients were studied by the indirect immunofluorescence technique to determine the prevalence of the following autoantibodies: islet cells (ICA), islet cells which fix complement (ICA-CF), thyroid microsomes (TMA), thyroglobulin (TGA), and gastric-parietal cells (PCA). A total of 54 IDDM patients belonging to two family groups were analyzed. 2. A significantly higher frequency of ICA-CF and TMA was detected among the siblings from multiplex families than among those from simplex families (18.7% vs 1.7%). 3. A prospective study of 5 ICA-positive siblings was undertaken, and 2 who later became diabetic were found to be positive to both ICA and ICA-CF. 4. The prevalence of islet-cell antibodies in these 54 Brazilian IDDM patients and their unaffected first-degree relatives from genetically mixed groups suggests that the humoral autoimmune mechanisms of the disease are probably identical to those observed in other populations of different ethnic backgrounds.

Prevalence of autoantibodies in simplex and multiplex families of Brazilian insulin-dependent diabetic patients

Forty-one simplex and 6 multiplex families of Brazilian IDDM patients were studied by the indirect immunofluorescence technique to determine the prevalence of the following autoantibodies: islet cells (ICA), islet cells which fix complement (ICA-CF), thyroid microsomes (TMA), thyroglobulin (TGA), and gastric-parietal cells (PCA). A total of 54 IDDM patients belonging to two family groups were analyzed. A significantly higher frequency of ICA-CF and TMA was detected among the siblings from multiplex families than among those from simplex families (18.7% vs 1.7%). A prospective study of ICA-positive siblings was undertaken, and 2 who later became diabetic were found to be positive to both ICA and ICA-CF. The prevalence of islet-cell antibodies in these 54 Brazilian IDDM patients and their unaffected first-degree relatives from generally mixed groups suggest that the humoral autoimmune mechanisms of the disease are probably identical to those observed in other population of different ethnic backgrounds

[Analysis of various epidemiological parameters in patients with diabetes mellitus type I in the city of Rio de Janeiro, Brazil]. / Análise de alguns parâmetros epidemiológicos em pacientes com diabetes mellitus tipo I na cidade do Rio de Janeiro.

The authors analyzed epidemiological data of 157 type I diabetes patients living in the city of Rio de Janeiro, Brazil. The mean age at the time of study 16 +/- 8.1 years (arithmetic mean +/- standard deviation) and the age at the time of the diagnosis was 12.5 +/- 7.4 years. The diabetes history span was 3.1 +/- 4.3 years and the interval between appearance of symptoms and diagnosis was 30.7 +/- 30.4 days. Neither seasonal nor sex dependent differences were observed, but there was an inverse correlation between the average monthly temperature in Rio de Janeiro and the number of newly diagnosed cases. A first grade family history was positive in 15.9% of patients (11% of type I diabetes). The autoimmunity history was positive in 4.1% of patients (mainly thyroid disease). An infectious disease history was positive in 7% of patients (mainly mumps). Our data suggests that some epidemiological aspects, observed among type I brazilian diabetic patients of a mixed genetic background, are similar to those observed in other populational groups of different ethnic origins.