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Minimally processed vegetables are washed and subsequently disinfected by immersion in water solutions with antimicrobials which reduce the initial pathogenic or spoilage microbial load. Chlorine remains one of the most widely used disinfectants for vegetables and hence the importance of studying its properties. The aim of this study was to evaluate the effect of peeling, cutting, and shredding on the effectiveness of chlorine (200 ppm) as a disinfectant in lettuce, carrot, and potato. Three independent repetitions of each experiment were completed, and data was statistically analyzed. Results showed that the maintenance of the chlorine concentration in the disinfectant solution, over time, depended on the vegetables' preliminary processing technique (whole, peeled, cut, or shredded) (p < 0.05). In general, the disinfection treatments studied reduced Escherichia coli by 1-8 logs. The addition of chlorine in the disinfectant solution allowed greater reduction in E. coli than using water immersions (p < 0.05) and disinfection times longer than 5 min did not improve these microbiological reductions (p>0.05). The vegetables' subdivision (whole, peeled, cut, or shredded) can affect both E coli's reduction and the vegetables' residual chlorine concentration. No trend was observed in terms of sensory differences and their relationship to the vegetables' processing and disinfection. These results suggest that each facility must validate its disinfection processes, according to the conditions established on site and reduction goals related to initial microbial counts, vegetables' quality, processing operations, and other important aspects.

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Parasporins represent a new functional class of Cry (crystal protein) toxins produced by the bacterium Bacillus thuringiensis (Bt). Unlike Cry toxins that demonstrate activity mainly against some insect cells, parasporins are characterized as being non-hemolytic, yet capable of preferentially killing some human cancer cells. Globally, six different parasporin types, PS1-PS6, based on protein sequence homology, have been identified in only four countries (Japan, Vietnam, India, and Canada). Herein we report the results of a screening study of 160 Bt isolates collected from the Caribbean island of Trinidad. One isolate (strain 64-1-94) was shown to kill human cancer cells and to contain one ps6 and two ps1 parasporin genes. The two ps1 genes were located approximately 6 kb apart from each other, sharing a similar spatial arrangement, and high sequence homology, with two plasmid-located ps1 genes, ps1Aa6 and ps1Ad1, recently isolated from a Japanese strain. Evidence is also presented that a parasporin gene reported previously for a Canadian strain, ps1Aa2, is most likely derived from a recombination event between these same two genes found in the Trinidadian and Japanese strains. Notably, all three strains share a ps6 parasporin gene, presumably located on a separate plasmid. These data suggest that the global population of ps1 genes may be have originated from a single pair of parasporin genes. Given the large geographical distance between the collection sites, which are located on both continental land masses and islands at sea, ps1 genes are able to retain a remarkable level of homology not easily explained.

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Radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia is based on the elimination of conduction of slow or fast intranodal pathway. To avoid potential atrioventricular (AV) block, a new technology has been developed, cryothermal ablation. We report a case of AV nodal reentrant tachycardia in whom direct cryoablation, without previous ice mapping, was successfully performed. Interestingly and as previously described, cryotherapy did not induce ectopic rhythms, the conventional surrogate during radiofrequency ablation.

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Se optimizó un ELISA de tipo indirecto en el cual se usan como antígenos de captura las proteínas de membrana externa del meningococo B presentes en la vacuna cubana VA-MENGOC-BC®. La presencia de anticuerpos específicos en muestras de sueros extraídas de individuos vacunados fueron detectadas con un conjugado anti-IgG humana: fosfatasa alcalina, revelándose la reacción con el sustrato específico p-nitrofenilfosfato. Se obtuvo el suero estándar a partir de un estándar de referencia, el rango de la curva de calibración es de 625 a 20 000 U/mL. Se seleccionó el suero control en la zona de mayor interés para las muestras y se determinaron las características del ensayo, cuya imprecisión intraensayo, interensayo y total fueron inferiores al 10 por ciento en la zona más lineal de la curva. La detectabilidad fue de 700 U/mL. Los estudios de recuperación, paralelismo y linealidad muestran una inexactitud inferior al 10 por cieto(AU)

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An indirect ELISA test was optimised in which B meningoccocus outer membrane proteins included in the Cuban Vaccine known as VA-MENGOC-BC were used as capture antigents. Specific antibodies in serum samples from vaccinated individuals were detected using a human anti-IgG conjugate, i.e. alklayne phosphatase, thus the reaction developed with a specific substrate called p-nitrophenilphophate. Standard serum was obtained from a reference standard, the gage curve range was 625 to 20,000/mL. The control serum was selected from the most interesting areas for the samples, hence, assay characteristics were determined. Intra-assay, inter-assay and total inaccuracies were lower than 10 in the most linear area of the curve. Detectability was 700/mL. Recovery, paralelism and linearity studies showed an under 10 inaccuracy.

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