Utilidad de los estudios serológicos en los centros de Atención Primaria para el diagnóstico precoz de la enfermedad de Lyme

Objective

The main aim of this study was to determine the usefulness of an early diagnosis of Lyme disease (LD) in Primary Health Care Centres (PHCC) using the ELISA test as serological screening technique.

Oxidative stress time course in the rat diaphragm after freezing-thawing cycles

Hyperthermia was shown to induce oxidative stress by uncoupling mitochondrial respiratory chain and to reduce superoxide dismutase (SOD) activity in muscles. Reactive carbonyl groups, malondialdehyde (MDA)-protein adducts, 3-nitrotyrosine immunoreactivity, Mn-SOD, and catalase were detected using immunoblotting in rat diaphragm specimens and homogenates thawed at room temperature (after previous storage at -80 degrees C) for 5, 15, 30, and 60 min, and 3, 6, and 24h to be subsequently and immediately stored at -80 degrees C. Mn-SOD activity was also measured in all muscles. Both total protein carbonylation (reactive carbonyl groups and MDA-protein adducts) and nitration were significantly increased over time, reaching their peaks in the diaphragms of the 60- and 15-min groups, respectively. Mn-SOD expression and activity were significantly reduced over time, while catalase expression showed no significant variation. Protein oxidation was significantly increased in the rat diaphragms exposed to freezing-thawing cycles of different time lengths, while Mn-SOD was substantially reduced in all muscles.     

Cultivation-independent assessment of the bacterial diversity of breast milk among healthy women

Breast milk has been shown to be an excellent and continuous source of commensal and potentially probiotic bacteria to the infant gut. Our aim was to evaluate the dominant bacteria existing in breast milk of healthy women and the potential role of transit through the vagina in the acquisition of breast milk microbiota using the 16S rRNA amplified gene approach. Samples of breast milk were aseptically collected, at day 7 after delivery, from five mothers whose neonates were born by vaginal delivery and from five others who had had their babies by programmed elective cesarean section. All mothers were healthy, had a full-term pregnancy and breastfed their infants. DNA extracted from biological samples was used as a template for PCR amplification of 16S rRNA gene sequences with universal bacterial primers; then the PCR products were analyzed by denaturing gradient gel electrophoresis (DGGE); finally, clone libraries of 16S rRNA gene sequences from 4 mothers (2 from each group) were constructed. PCR DGGE patterns and clone libraries suggest that each woman had a specific bacterial pattern in her breast milk, and confirm, at the molecular level, that breast milk of healthy women is a source of commensal bacteria to the infant gut. They also reinforce recent molecular studies which have shown that lactic acid bacteria colonization is not significantly related to the delivery method.     

Emergency prevention of extinction of a transgenic allele in a less-fertile transgenic mouse line by crossing with an inbred or outbred mouse strain coupled with assisted reproductive technologies

Certain transgenic mouse lines are difficult to breed or archive and, consequently, their transgenes become lost. We examined a C57BL/6 mouse line (B6-tg), transgenic for green fluorescent protein (GFP) with low fertility, and its crosses with the more prolific inbred C3HeB/FeJ (C3) and outbred Swiss (SW) strains in order to assess the possibility of emergency prevention of extinction of a transgenic allele by using assisted reproductive technologies (ART). Out-crossing was performed by natural mating or in vitro fertilisation (IVF) with heterozygous mice. Most of the crossing combinations resulted in improved archiving and rederivation efficiencies of the transgenic allele. Natural crossing increased both mean litter size by two to three pups and the superovulatory rate from 69% for B6-tg to 70-90% for females from the out-crosses. Each plug-positive B6-tg female yielded an average of 4.6 two-cell embryos, whereas females from the out-crosses produced three- to fivefold that amount. After thawing, 13% of B6-tg embryos and 6-12% of out-crossed embryos developed into transgenic pups after transfer into recipients. After IVF with cryopreserved spermatozoa, cleavage rates were 4% for B6-tg, 22-37% for B6-tg oocytes out-crossed with C3 and SW spermatozoa, 9-49% for gametes from out-crossed mice and 28-44% for back-crosses with B6 oocytes. Transgenic pups were not derived from IVF with B6-tg gametes when either fresh or cryopreserved spermatozoa were used. Rederivation efficiencies were 7% and 4% from out-crosses of B6-tg oocytes with C3 and SW spermatozoa, respectively, 6-22% for gametes from out-crossed mice and 4-10% for the back-crosses. Although out-crossing changes the original genetic background, the strategy of crossing coupled with ART prevents the extinction of an allele of interest, especially where archiving and rederivation of the transgenic line fail.     

Human benefits of animal interventions for zoonosis control

Although industrialized countries have been able to contain recent outbreaks of zoonotic diseases, many resource-limited and transitioning countries have not been able to react adequately. The key for controlling zoonoses such as rabies, echinococcosis, and brucellosis is to focus on the animal reservoir. In this respect, ministries of health question whether the public health sector really benefits from interventions for livestock. Cross-sectoral assessments of interventions such as mass vaccination for brucellosis in Mongolia or vaccination of dogs for rabies in Chad consider human and animal health sectors from a societal economic perspective. Combining the total societal benefits, the intervention in the animal sector saves money and provides the economic argument, which opens new approaches for the control of zoonoses in resource-limited countries through contributions from multiple sectors.     

A MUFA-rich diet improves posprandial glucose, lipid and GLP-1 responses in insulin-resistant subjects

OBJECTIVE: To study the effects of three weight-maintenance diets with different macronutrient composition on carbohydrate, lipid metabolism, insulin and incretin levels in insulin-resistant subjects. METHODS: A prospective study was performed in eleven (7 W, 4 M) offspring of obese and type 2 diabetes patients. Subjects had a BMI > 25 Kg/m2, waist circumference (men/women) > 102/88, HBA1c < 6.5% and were regarded as insulin-resistant after an OGTT (Matsuda ISIm <4). They were randomly divided into three groups and underwent three dietary periods each of 28 days in a crossover design: a) diet high in saturated fat (SAT), b) diet rich in monounsaturated fat (MUFA; Mediterranean diet) and c) diet rich in carbohydrate (CHO). RESULTS: Body weight and resting energy expenditure did not changed during the three dietary periods. Fasting serum glucose concentrations fell during MUFA-rich and CHO-rich diets compared with high-SAT diets (5.02 +/- 0.1, 5.03 +/- 0.1, 5.50 +/- 0.2 mmol/L, respectively. Anova < 0.05). The MUFA-rich diet improved insulin sensitivity, as indicated by lower homeostasis model analysis-insulin resistance (HOMA-ir), compared with CHO-rich and high-SAT diets (2.32 +/- 0.3, 2.52 +/- 0.4, 2.72 +/- 0.4, respectively, Anova < 0.01). After a MUFA-rich and high-SAT breakfasts (443 kcal) the postprandial integrated area under curve (AUC) of glucose and insulin were lowered compared with isocaloric CHO-rich breakfast (7.8 +/- 1.3, 5.84 +/- 1.2, 11.9 +/- 2.7 mmol . 180 min/L, Anova < 0.05; and 1004 +/- 147, 1253 +/- 140, 2667 +/- 329 pmol . 180 min/L, Anova <0.01, respectively); while the integrated glucagon-like peptide-1 response increased with MUFA and SAT breakfasts compared with isocaloric CHO-rich meals (4.22 +/- 0.7, 4.34 +/- 1.1, 1.85 +/- 1.1, respectively, Anova < 0.05). Fasting and postprandial HDL cholesterol concentrations rose with MUFA-rich diets, and the AUCs of triacylglycerol fell with the CHO-rich diet. Similarly fasting proinsulin (PI) concentration fell, while stimulated ratio PI/I was not changed by MUFA-rich diet. CONCLUSIONS: Weight maintenance with a MUFA-rich diet improves HOMA-ir and fasting proinsulin levels in insulin-resistant subjects. Ingestion of a virgin olive oil-based breakfast decreased postprandial glucose and insulin concentrations, and increased HDL-C and GLP-1 concentrations as compared with CHO-rich diet.