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Biomedical subjects

B Sanz

Publications and source records attributed to B Sanz.

45 records · Page 3Linked to original sources

A method to assess the bacterial content of refrigerated meat.

A new method has been developed to estimate the levels of gram-negative bacteria on refrigerated meat. The method is based on the aminopeptidase activity of these bacteria, which cleaves L-alanine-p-nitroanilide to yield p-nitroaniline, which is easily determined spectrophotometrically. This method allows the determination of levels around 10(6) to 10(7) CFU cm-2 in about 3 h. Because of the yellow color of p-nitroaniline, bacterial loads around 10(7) CFU cm-2 develop a color intense enough to be detected with the naked eye.

Aminopeptidases↗

Effect of combined ultrasonic and heat treatment (thermoultrasonication) on the survival of a strain of Staphylococcus aureus.

The combined effect of ultrasonic waves (20 kHz, 150 W) and heat treatment applied simultaneously (thermoultrasonication) on the survival of a strain of Staphylococcus aureus was studied in 0.05 M-phosphate buffer pH 6.8 and ultra-heat-treated whole milk. This combined process decreased by 63% the decimal reduction times for the heat treatment when the organism was suspended in buffer and by 43% when suspended in milk. These effects were much greater than the additive effect of the two agents considered independently.

Animals↗

Effect of growth temperature on lipid composition of Streptococcus faecium.

The effect of growth temperature on the lipid and fatty acid composition of Streptococcus faecium has been studied. No differences in the qualitative composition of S. faecium lipids were observed. In all isolated fractions (neutral lipids, glycolipids, and phospholipids plus other polar lipids), the major fatty acids were palmitic (C-16:0), palmitoleic (C-16:1), octadecenoic (C-18:1), and cyclopropane (C-19:0). Changes in the fatty acid composition of the different fractions were observed which depended on growth temperature; the most significant one was the decrease of octadecenoic acid and the increase of palmitic acid in glycolipids and polar lipids as the temperature increased. The level of cyclopropane C-19:0 was approximately eightfold lower at 8 degrees C than at the other temperatures tested (20, 30, and 45 degrees C).

Diglycerides↗

Utilization of cellobiose and D-glucose by Clostridium thermocellum ATCC-27405.

Cultures of Clostridium thermocellum ATCC-27405, maintained on cellulose and not adapted to grow on glucose utilize cellobiose preferentially over D-glucose, and are only able to initiate growth on D-glucose when the cellobiose has been exhausted from the growth medium. However, D-glucose is the carbon source preferentially utilized when cultures of this microorganism, previously adapted for growth on glucose, are transferred to a medium with equivalent concentrations of both sugars. One reason for the preferential utilization of glucose over that of cellobiose might be the competitive inhibition of cellobiose phosphorylase by intracellular glucose accumulation. When in the glucose-adapted cultures the pressure to grow on glucose as the sole carbon source is again released, both sugars can be simultaneously utilized.

Bacterial Proteins↗

A note on the effect of combined ultrasonic and heat treatments on the survival of thermoduric streptococci.

The combined destructive effect of ultrasonic waves and heating on micro-organisms has been investigated using as a model two species of thermoduric streptococci. Ultrasonic and heat treatments applied simultaneously were much more destructive than the additive effect of the two agents considered independently. Compared with heat alone, the simultaneous application of ultrasonic vibration and heat reduced the resistance of the organisms 6-11 fold.

Food Microbiology↗

Selective release of glutamine and glutamic acid produced by perfusion of GLP-1 (7-36) amide in the basal ganglia of the conscious rat.

Glucagon-like peptide 1 (GLP-1)(7-36) amide, a member of the family of glucagon and related peptides, synthesized by intestinal L cells, has a well-defined distribution in rat brain. In addition, specific GLP-1(7-36) amide receptors have also been localized in some regions of the brain, which suggests that this novel gut-brain peptide has a role in brain function. Accordingly, we investigated the effects of this peptide on the release of amino acid neurotransmitters in the basal ganglia of conscious rats after its perfusion through a concentric "push-pull" cannula system with an artificial cerebrospinal fluid. To obtain stable basal levels of amino acids, the basal ganglia were perfused with an artificial cerebrospinal fluid for 2 h at a flow rate of 20 microliters/min and then with GLP-1(7-36) amide for 10 min, followed by 40 min poststimulation perfusion. GLP-1(7-36) amide produced an immediate increase (p less than 0.01) of the extracellular levels of glutamine and glutamic acid in the basal ganglia. By contrast, this peptide has no effect on the levels of aspartic acid, glycine, and serine. Because glutamine is a metabolic precursor of glutamic acid and is synthesized almost exclusively in astrocytes, these findings suggest a stimulatory effect of GLP-1(7-36) amide on astrocytes and/or neurons of the rat basal ganglia.

Animals↗

Prick-prick with fresh foods in patients with latex allergy.

The quick spread of AIDS and other contagious infectious diseases has resulted in what was first voluntary, and subsequently recommended and compulsory, use of protection from contact with blood or bodily fluids. This protection has been especially widespread in the healthcare field. In the in vivo diagnosis of food allergy, it has been proven that the skin prick-prick test is sometimes more sensitive than skin prick test with commercial extracts. The aim of our study was to prove that handling fresh foods prepared for the prick-prick test with latex gloves can tamper with the results in patients with latex allergy. Statistically significant differences were found (p <0.001) between patients and controls in the prick-prick tests against the different foods after handling with latex gloves. No significant differences were found in controls for each prick-prick test for food with or without manipulation with latex gloves. Significant differences were found in the group of patients when performing prick-prick with the different foods before and after manipulation with latex gloves. We also observed that there were significant differences in prick-prick test between patients with latex sensitization and nonsensitized controls, and that the results of prick-prick test varied for each patient depending on whether or not foods had been handled with latex gloves.

Adult↗