Characterization of Listeria monocytogenes and Listeria innocua from a vegetable processing plant by RAPD and REA.

The incidence of Listeria monocytogenes in a vegetable processing plant was investigated over a 23-month period. Frozen ready-to-eat vegetable samples, well as the plant environment, were sampled. The molecular subtyping techniques, Random Amplified Polymorphic DNA (RAPD) and Restriction Endonuclease Analyses (REA), were performed to help investigate the origin and routes of Listeria dissemination. The low and sporadic incidence of L. monocytogenes made it impossible to establish an epidemiological sequence in the processing plant, though a case of cross-contamination between tomato and ratatouille was detected. Listeria innocua subtyping, however, allowed us to determine the prevalence of several strains in vegetables, and their presence on machinery samples suggested the possibility of cross-contamination during processing. The low incidence of L. monocytogenes indicated that the risk of listeriosis transmission by vegetable consumption is low. On the other hand, the isolation of the same strain of L. innocua in several surveys pointed out the risk of colonisation on surfaces and machinery. The persistence of Listeria spp. is a cause for concern as can lead to future contamination of vegetables processed in the plant and to a possible increased risk for health. Therefore, periodic controls for the presence of Listeria spp. and a further review of the cleaning and disinfection procedures used in frozen vegetable plants are recommended.

Random amplified polymorphic DNA typing applied to the study of cross-contamination by Listeria monocytogenes in processed food products.

The presence of Listeria spp. was investigated in 369 samples of cooked meat products and 52 of smoked salmon. Incidences of 17.6% for cooked meat and 38.5% for smoked salmon samples were found. All Listeria monocytogenes isolates (34 from meat products and 16 from smoked salmon) were typed serologically and by random amplified polymorphic DNA (RAPD) typing using primers HLWL74 (5'-ACGTATCTGC-3'), HLWL85 (5'-ACAACTGCTC-3'), and OMP-01 (5'-GTI'GGTGGCT-3'). Strains from cooked meat products were characterized and compared in relation to their origin. The detection of identical strains in products of different type and brand packed on the same date suggested cross-contamination, probably during the slicing process. All L monocytogenes isolates from smoked salmon were indistinguishable by serotyping and RAPD, suggesting that this strain was highly disseminated and adapted to the treatment used for the preservation of this food. RAPD subtypes were analyzed using GelCompar version 4.1 software and the unweighted pair method using arithmetic averages, and six groups with at least 78% similarity were established. Serotyping and RAPD results were in concordance, although RAPD showed a higher discriminatory power with L. monocytogenes isolates from meat products. RAPD is an easy method that could be useful to detect cross-contamination occurring during postprocessing manipulations.

A comparison of molar root canal preparations using Flexofile, Canal Master U, and Heliapical Instruments.

There are many instruments and techniques for cleaning and shaping the root canal system, but none achieves the ideal preparation, especially in curved canals. This study compared the step-back technique, using Heliapical and Flexofiles, with the Canal Master technique, using Canal Master U instruments. The Bramante method evaluated and compared the results. Final analysis showed that root canals prepared with Canal Master U instruments and technique were significantly rounder, and had less transportation than those prepared by the Heliapical and Flexofiles using the step-back technique.

[Tobacco use in the province of La Garrotxa. Comparative study 1982-1986]. / Consumo de tabaco de la comarca de La Garrotxa. Estudio comparativo 1982-1986.

The objective of this study is to compare the prevalence of smoking among young students of the area of La Garrotxa between 1982 and 1986. Two surveys were made, following the same methodology, interviewing two samples of student population 13 to 25 years old. The total number of interviewed students were 1,039 in 1982 and 1,133 in 1986. The smoking prevalence was lower in 1986 than in 1982, decreasing from 55% to 35%. This difference was due to a decrease in the prevalence of those younger than 17 in both sexes and remained stable after adjusting for age, sex and school. The initial age for experimental smoking was delayed by 1 year from 1982 to 1986. The proportion of smoker parents was not different between both periods. We conclude that smoking habit has decreased in younger people, and this is probably due to a delay in the age of smoking initiation.

The Catalonia survey: Personality and intelligence structure in a sample of compulsive gamblers.

A sample of fifty-seven pathological gamblers and one hundred and fifteen controls (two per pathological gambler, matched as regards age and sex) was investigated. This sample received a complex battery of psychometric tests designed to evaluate two different axes: psychopathology and intelligence. The results obtained show that pathological gamblers have an unstable family and work background, that pathological gambling correlates with other addictions (alcohol, illness prone behavior, absenteeism, risk working, living alone and bereavement), that all the general and specific psychopathology vectors were significant in the addicts, and that the pathological gamblers' intelligence has characteristic factors.

[Immunoglobulins and the complement system in colorectal cancer]. / Inmunoglobulinas y sistema del complemento en el cáncer colorrectal.

In the present paper is studied the concentration in peripheral blood of immunoglobulins IgG, IgA, IgM and factors C3 and C4 of the complement system in a group of 120 patients with colorectal cancer operated on with radical intention. Preoperative values are compared to postoperative results and the values obtained on diagnosis of tumoral recurrence with the object of describing possible immunologic alterations existent in the patient with colorectal carcinoma. It is concluded that there are no significant relations between the biochemical parameters studied and age, sex, tumoral localization and Duke's clinical stages. Patients with pre and postoperative IgA values above normal present a poor prognosis, with an associated recurrence of 60% (p = 0.001) and 80% (p = 0.000), respectively; postoperative C3 levels above normal also represent a factor of poor prognosis, recurrence appearing in 80% (p = 0.001) and metastases in 85% (p = 0.000).