Clara M. López

Brodifacoum Poisoning with Toxicokinetic Data

The case of a 46-year-old woman who survived after a brodifacoum poisoning is presented. The patient was admitted due to a severe coagulopathy. Initial prothrombin time and activated partial thromboplastin time were both greater than 110 seconds and the patient suffered severe gastric and pulmonary hemorrhage requiring fresh frozen plasma transfusion and parenteral phytonadione administration (up to 100 mg per day). Serum brodifacoum levels were determined by HPLC during seven months. Five days after admission, serum brodifacoum level was 1302 ng/ml. Serum brodifacoum levels decreased till day 209 when became not detectable. Brodifacoum elimination showed a first order kinetic and a 56-day half-life. Investigation of superwarfarin should be considered in any patient with vitamin K dependent coagulation disorder. It would be also useful to obtain periodic brodifacoum levels and build the corresponding elimination curve to help direct phytonadione therapy in poisoned patients.

Thermotolerant Campylobacters in domestic animals in a defined population in Buenos Aires, Argentina

We assessed the prevalence of Campylobacter jejuni in animals in a region of unsatisfied basic needs in the city of Buenos Aires and studied a few risk factors. First we conducted a census to identify all dwellings having pet animals (dogs, cats, and birds). Fecal samples were then taken for isolation and identification of strains. We observed 17% prevalence for dogs (95% CI: 13, 22), 16% for cats (95% CI: 8, 27) and 19% for birds (95% CI: 5, 42). In dogs, the highest prevalences were found in summer and in animals <1 year old; in cats, in autumn and those aged 3-5 years. Strains were identified as C. jejuni biotype II in 70% of isolates. In the population described here, dogs, cats and birds kept in households were potential sources of human Campylobacter infections.

Experimental Infection with Toxocara cati in BALB/c Mice, Migratory Behaviour and Pathological Changes

Experimental inoculations of 1000 Toxocara cati larval eggs were carried out in 18 BALB/c mice. The T. cati eggs used for inoculation were collected from the faeces of naturally infected cats. Euthanasia was performed on two mice on days 1, 2, 3, 4, 5, 6, 14, 21 and 28 post‐inoculation (p.i.). Tissue samples were taken for digestion and histopathology. Larvae were recovered from all infected mice and the average of all larvae recovered was 28.3% (95%; CI: 14.1–42.4). Maximum number was obtained from liver on days 1 and 2 p.i.; from the lung on day 2 p.i. and from the brain on day 28 p.i. In muscle, the recovery was high as from day 3 p.i., with the maximum obtained on day 28 p.i. Superficial foci of congestion and haemorrhage were macroscopically observed in the lungs between days 2 and 5 p.i. and in the brain between days 3 and 6 p.i. Microscopic lesions were observed in the liver between days 2 and 14 p.i., with periportal and subcapsule inflammatory infiltrates. In the lungs, haemorrhages and inflammatory infiltrates can be observed in the alveolar parenchyma, close to bronchioles and large blood vessels. In the brain, congestive areas without inflammatory reactions were seen. In muscle, the presence of inflammatory infiltrates and degenerated muscle can be observed surrounding a parasite larva. These same lesions were observed in myocardium and pericardium. The kidneys were congested with inflammatory infiltrates. The inflammatory cells present in all the tissues studied were lymphocytes, neutrophils and a few eosinophils. Formation of granulomas or signs of larva encapsulation were not observed. The migratory pattern of T. cati larvae in BALB/c mice and its tendency to become concentrated in the muscle reinforce the importance of the mouse as a paratenic host for the parasite’s cycle in the environment.

Immunological and hematological response in experimental Toxocara canis-infected pigs

The relationship between the immunological and hematological response to infection was studied in pigs inoculated experimentally with Toxocara canis. Two groups of four pigs were infected with doses of 1000 and 2000 infective eggs, respectively. Two uninfected animals were used as negative controls. Blood samples were collected from each pig once a week. Serological examination by ELISA to determine antibody levels against T. canis L2/L3 excretory-secretory (ES) antigens showed values higher than the positive cut-off point (1:32) for both the infected groups. These values increased from day 7 p.i. and remained high during the experimental period until day 56. Significant differences were recorded for the two inoculating doses (p</=0.01) from day 14 to 42 p.i. Western blots run on day 7 p.i. with serum from the 2000 eggs group showed two polypeptide bands of 70 and 55kDa. These same bands were observed for both infected groups from day 15 p.i. until the end of the experiment. Eosinophil counts were significantly higher (p</=0.05) for both inoculated groups between weeks 2 and 7 p.i. as compared with the control group. No significant changes were observed for other blood parameters. The pig is a useful animal model since T. canis induces an early immunological response and ELISA can detect the presence of these antibodies against T. canis L(2)/L(3) ES antigens in animals inoculated with low doses of Toxocara eggs.

First analytical chemistry study on drug abuse in the Buenos Aires (Argentina) University students

One hundred samples were randomly selected from urine specimens collected from Buenos Aires University students, 50 males and 50 females, whose ages ranged from 19 to 47 years. Cocaine (COC), cannabinoids (CNNs), amphetamines (AMs), benzodiazepines (BZDs), barbiturates (BBTs), opiates (OPs) and salicylates (SAs) were searched for by ELISA, FPIA, normalized TLC, HPLC and GC/MS techniques. The presence of COC was detected in five samples, CNN in two and SA in twelve. No evidence of AMs, BZDs, BBTs or OPs was found.

Quantification of Cotinine in Plasma and Urine by HPLC‐UV Detection

Abstract Cotinine, the main metabolite of nicotine in man, is widely used as an abstention marker to Nicotiana tabacum smoke, as well as to evaluate passive inhalation of tobacco smoke by non‐smokers. Development and validation of a reversed‐phase high performance liquid chromatography (RP‐HPLC) method with ultraviolet (UV) detection for identification and quantification of cotinine in human plasma and urine are described. After diluting plasma with distilled water (1/6), NaOH 5 M (1:1) was added to both matrices and cotinine extracted using a RP 18 solid phase extraction column (SPE). Extracts were resuspended in mobile phase phosphate buffer pH 6.8:acetonitrile (90:10) and injected into a Lichrospher 100 RP‐18 column (5 µm). The UV detector was set to 260 nm. Linear calibration curves in the range of 10–1000 ng/mL of cotinine with correlation coefficients greater than 0.999 were obtained. Within‐run and between‐run accuracy was less than 5%. Cotinine detection limit was 20 ng/mL. The proposed chromatographic system allows cotinine to be separated from caffeine.

Condiciones sanitarias de los comedores comunitarios del conurbano de Buenos Aires, Argentina

Debido a la importancia que la inocuidad de los alimentos entrana para la salud publica, se procuro determinar la calidad microbiologica de los alimentos que consumen los usuarios de los comedores comunitarios del conurbano de Buenos Aires, Argentina. Se trata de un estudio descriptivo, cuyo universo lo conformaron tres municipios con indices medianos y altos de pobreza, de los que se extrajo al azar una muestra de 52 comedores. La informacion se recolecto desde abril de 1994 hasta abril de 1995 inclusive, por medio de encuestas, observaciones directas y analisis microbiologicos del agua y los alimentos servidos. Los analisis del agua y los alimentos se ajustaron, respectivamente, a las recomendaciones del Codigo Alimentario Argentino y de la Comision Internacional de Especificaciones Microbiologicas para Alimentos. Los resultados se interpretaron segun los valores para alimentos cocidos acordados por el Grupo de Trabajo de Control de Alimentos. La parte microbiologica del estudio mostro que en 28 (54%) de los comedores la comida o el agua era inadecuada y en 11 (21%), ambas eran inadecuadas. Bacillus cereus fue la bacteria patogena que se encontro con mayor frecuencia en los alimentos analizados. Los factores significativamente asociados con condiciones microbiologicas insatisfactorias de las comidas y el agua fueron no desinfectar el agua (P = 0,009), la falta de higiene en el ambiente (P = 0,03), la presencia de roedores e insectos (P = 0,05), el sistema de provision de materias primas (P = 0,01) y un numero de usuarios menor de 100 (P = 0,008). Se concluyo que la desinfeccion del agua y la limpieza general de los comedores son medidas que pueden implantarse por medio de intervenciones educativas en materia de higiene y manipulacion de alimentos dirigidas a los encargados y empleados de los comedores. Los resultados obtenidos tambien apoyan la conveniencia de incluir la evaluacion sanitaria de los alimentos entre los criterios de evaluacion general de los programas de asistencia alimentaria.

Variations in rat biochemical parameters after buckshot implant

Twenty eight albino Wistar rats were implanted with two 100 mg lead spheres: 14 received the implant in the peritoneum (P) and 14 in the thigh (T). Variations in the activity of delta-aminolevulinic dehydratase (ALAD), of urinary delta-aminolevulinic acid (ALAU), of hematoporphyrins (HP) and of lead blood levels (BPb) were then determined at 30, 60 and 90 days with respect to basal values. Parallel determinations were performed by the same schedule in 7 rats implanted with two glass beads and in 8 sham animals receiving surgical incision alone. Techniques employed for ALAD were Berlin and Schaller; for ALAU, Tomokuni and Ogata; for HP, Piomelli; and for BPb, atomic absorption spectrophotometry. As indicators of lead presence, HP and ALAU proved better, both in P and in T rats. The replacement of lead buckshot for small game hunting by other less toxic elements is recommended.