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Biomedical subjects

M Manzano

Publications and source records attributed to M Manzano.

10 recordsLinked to original sources

Polymerase chain reaction assay for detection of Campylobacter coli and Campylobacter jejuni in poultry meat.

Primers of 16S rRNA and flaA genes were used to optimise a PCR technique for detecting thermotolerant campylobacters in poultry meat. Different methods for crude DNA extraction were also evaluated. The use of flaA primers and extraction of nucleic acid by boiling and proteinase K gave good results in the detection of Campylobacter either in artificially or naturally contaminated foodstuffs. The lowest sensitivity limit for the PCR reaction was 10(1)-10(2) thermophilic Campylobacter cells either in pure cultures or in artificially and naturally contaminated poultry skins, corresponding to a concentration of 10(2)-10(3) Campylobacter/ml or g product. The PCR method we devised had a high sensitivity and specificity. It appears to give better results than conventional methods and is very easy and fast, requiring only eight hours to detect thermotolerant Campylobacter from poultry meat. In contrast, conventional methods require almost 4 days.

Animals

Adaptation of a Saccharomyces cerevisiae strain to high copper concentrations.

A strain of Saccharomyces cerevisiae has been adapted to increasing concentrations of copper at two different pH values. The growth curve at pH 5.5 is characterized by a time generation increasing with the amount of added copper. A significant decrease of cell volume as compared with the control is also observed. At pH 3 the cells grow faster than at pH 5.5 and resist higher copper concentrations (3.8 against 1.2 mM). Experimental evidence indicates that, after copper treatment, the metal is not bound to the cell wall, but is localized intracellularly. A significant precipitation of copper salts in the medium was observed only at pH 5.5. Increased levels of superoxide dismutase (SOD) activity were observed in copper-treated cells and which persisted after 20 subsequent inocula in a medium without added metal. On the contrary, catalase activity was not stimulated by copper treatment and, hence, not correlated with SOD levels. The mechanism of copper resistance, therefore, probably involves a persistent induction of SOD, but not of catalase, and it is strongly pH-dependent.

Adaptation, Physiological

Interaction among heavy metals and methanol affecting superoxide dismutase activity in Saccharomyces cerevisiae.

1. Three strains of Saccharomyces cerevisiae have been exposed to methanol both in the presence and absence of heavy metal ions. The growth curves and the superoxide dismutase activity were determined. 2. The presence of alcohol, copper or cadmium alone did not give strong cytotoxic effects, while methanol plus cadmium yielded a growth inhibition in two strains. 3. SOD levels were stimulated by copper, while methanol did not affect SOD in this non-methylotrophic yeast, indicating the need of alcohol assimilation to stimulate SOD. Cadmium had no inducing effects on SOD levels.

Cadmium

Subperiosteal implants.

This paper analyzes 115 cases of subperiosteal implants placed during a 15-year period by means of the same surgical technique. The majority of implants were in women (86%) in both the maxilla and mandible. The varieties of implants placed were grouped by totals for statistical purposes: Kennedy classes I and II, Universal, and interdental. Although details of the surgical and prosthetic techniques are not included in this report, the procedures carried out by other authors are described. The majority of the implants evaluated had been in place for from 5 to 10 years (58.3%). The implants that experienced the highest levels of success are the completed designs in the mandible and the interdental in the maxilla. In both cases, the best results were observed when the antagonist was a complete-denture prosthesis.

Adult

Microbiological quality of artisanal ice cream.

In the course of the years 1990 and 1991, 396 samples of artisanal ice-cream had been collected from different ice-cream shops in Udine and province and analysed. All tested flavours contained aerobic germs, coliforms, Enterococci and yeasts in different quantities. In the analysed samples neither Salmonellae spp., nor Listeria monocytogenes nor Staphylococcus aureus were detected. Numerous species of coliforms and yeasts were randomly isolated and identified. The statistical analysis, used to compare the variables (flavour, month, year), showed significant differences among the samples analysed in the two years. In September, the means of the total aerobic count were significantly different from the ones of July and of August. No significant differences were noted in the means of coliforms, total aerobic counts and yeasts in the different flavours. The techniques for recovery of freeze-stressed coliforms in artificially contaminated samples of ice-cream showed that the three techniques, which use both selective and non-selective mediums, are better than those ones, which use only selective mediums. Lastly, with regard at the coliform values, the ice-creams tested have small-medium quality. In fact 26% of the ice-creams cannot be sealed, according to the Italian Ministry Ordinance (October 11, 1978).

Enterobacteriaceae

Effects of copper and cadmium on growth, superoxide dismutase and catalase activities in different yeast strains.

1. Three strains of Saccharomyces cerevisiae have been adapted in vitro upon treatment with copper or cadmium. Growth rate, cellular size, metal uptake, superoxide dismutase and catalase activities were measured. 2. Growth rate and metal uptake are quite different among the yeast strains and also for copper and cadmium treatment. At the employed concentrations, only cadmium chiefly affects the cellular volume. 3. Cu, ZnSOD activity is stimulated in the presence of copper, while it is lightly inhibited in the presence of cadmium. Catalase level remains almost unchanged in the conditions tested. This lack of correlation is then discussed.

Cadmium

Changes in the concentration and composition of biliary and serum bile acids in the young domestic fowl.

1. Concentrations of biliary and serum bile acids, their molecular compositions and serum cholesterol concentrations were determined in chicks at 2, 3, 4 and 6 weeks of age. 2. The concentration of biliary bile acid was maximal at 3 to 4 weeks, decreasing by 6 weeks of age. 3. The serum concentration of bile acid was maximal at three weeks of age. 4. Serum total cholesterol increased from two weeks and was maximal at 6 weeks of age. 5. Chenodeoxycholic acid was the predominant biliary unconjugated bile acid. 6. Tauro-chenodeoxycholic acid and tauro-cholic acid were the dominant molecular species of biliary and serum conjugated bile acid.

Age Factors