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Biomedical subjects

J Hernández

Publications and source records attributed to J Hernández.

At least 19 recordsLinked to original sources

Porcine circovirus type 2 antibody detection in backyard pigs from Mexico City.

PCV2 antibodies have been found in pigs from all continents. However, this finding has been mainly studied in domestic swine reared under intensive production conditions. Mexico City, with a human population over 19 million in 2005, has both urban and rural areas. The pig production in its rural area is based on small family backyard farms. Taking into account this rather unique form of rearing pigs, the objective of this study was to determine the seroprevalence in backyard pigs from the rural area of Mexico City. A total of 695 backyard pig serum samples from 108 small family farms belonging to seven municipal areas were studied by immunoperoxidase monolayer assay technique. One hundred six out of the 108 family farms (98.14%) had at least one positive serum sample. On the other hand, 136 (19.57%), 264 (37.99%) and 248 (34.82%) pigs had low, intermediate and high titres to PCV2, respectively. Only 53 samples (7.63%) were negative for PCV2 antibodies. No apparent differences in antibody titre groups were observed among backyard pigs from the different municipal areas. In conclusion, the present study, the first one performed in this kind of extensively produced pigs, indicates that PCV2 is ubiquitous in backyard pigs from Mexico City.

Animals↗

Use of dogs as indicators of metal exposure in rural and urban habitats in NW Spain.

Many different species have been used in environmental biomonitoring studies in diverse habitats including forest, farmland, and urban and sub-urban areas. However, there is little information on domestic animals living in rural or urban habitats and exposed to the same pollutants as the human population. In this connection, pets could prove to be good indicators of human metal exposure since they closely share the same environment as their owners, and are therefore exposed, at least in part, to the same pollutants. The present study investigated toxic metal exposure in dogs in NW Spain and compared metal exposures between dogs from rural and urban habitats, considering the influence of diet, sex and age. Samples of liver and kidney from 57 male and female dogs, aged between 6 months and 18 years, were collected after euthanasia at veterinary clinics. Samples were acid-digested and metal concentrations determined by ICP-MS. Geometric mean concentrations of metals in the liver and kidney (microg/kg wet weight) were 12.6 and 15.9 for arsenic, 58.0 and 175 for cadmium, 32.7 and 53.4 for mercury, and 57.7 and 23.1 respectively. Hepatic lead concentrations were significantly higher (p<0.05) in dogs fed commercial diets than dogs fed home-made feed (32%) or a mixture of commercial and home-made feeds (95%). Mercury concentrations in the kidney were significantly higher (3-fold, p<0.05) in dogs from urban areas than in dogs from rural areas. Cadmium levels in kidney were significantly higher (p<0.05) in females (67%) and increased with age (p<0.001). Although no human samples were obtained in this study and no direct correlations between dogs and human metal exposure have been conducted, given our results pets could be suggested as surrogate indicators of human metal exposure.

Animal Nutritional Physiological Phenomena↗

Development of a simple and rapid method based on polymerase chain reaction-based restriction fragment length polymorphism analysis to differentiate Helicobacter, Campylobacter, and Arcobacter species.

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of amplified DNA fragment of the 16S and 23S rRNA genes was performed on 35 Helicobacter, 24 Campylobacter, and 15 Arcobacter strains. PCR amplification generated a 1004-bp fragment of 16S rDNA and a 2.6-Kbp fragment of 23S rDNA from each strain. The amplicons were digested with DdeI and HpaII, respectively. For both assays, distinctive profiles were obtained for each genus. 23S rDNA PCR-RFLP analysis with HpaII enzyme identified Campylobacter and Helicobacter strains at the species level. Analysis of 16S rRNA gene with DdeI enzyme was not useful for the specific identification of Campylobacter and Arcobacter, although it discriminated among Helicobacter species. The PCR-RFLP technique allowed for the discrimination among these three related genus with only one restriction enzyme; therefore it can be a simple, rapid, and useful method for routine identification.

Arcobacter↗

Influence of copper status on the accumulation of toxic and essential metals in cattle.

The aim of the present study was to assess whether the use of pig slurry and associated copper accumulation in calves grazing pastures fertilized with pig slurry from the Deza region in NW Spain has a significant influence on toxic metal and essential metal levels, and to investigate whether copper accumulation is correlated with the levels of these other metals. Correlations between copper, toxic metals (cadmium, lead) and essential metals (molybdenum, iron, zinc, selenium, manganese and cobalt) concentrations were evaluated in liver and kidney of 195 calves from the region of Deza. Metal concentrations were determined by ICP-OES and correlations between pairs of elements by Pearson correlation analysis. There was a strongly significant positive association between copper and lead in the liver. Considering the trace metals, copper in the liver showed significant positive correlations with cobalt in both liver and kidney, and with molybdenum in the liver. In addition, significant correlations were observed between copper and most essential metals in kidney. These associations are similar to those found in different animal species experimentally dosed with copper and other metals, as well as in cattle exposed to normal copper concentrations.

Animals↗

Sensitization to Anisakis simplex s.l. in a healthy population.

The main objective of this study was to determine the degree of sensitization to Anisakis simplex s.l. in healthy population. Using the determination of specific IgE, we studied the seroprevalence against A. simplex s.l. in blood donors selected at random in the region of Antequera (Southern Spain). We detected 22.1%. The immunoblotting technique revealed a band of approximately 60 kDa in the serum of individuals who also exhibited high values of specific IgE against A. simplex s.l. This band would be useful for diagnosis.

Adolescent↗

Levels of HSP70 in HIV(+) patients in different viroimmunological states.

The aim of the study was to establish an association between the viroimmunological status of HIV positive patients and their levels of the 70-kD heat shock protein (Hsp70). The longitudinal retrospective case study involved 61 patients at the University Hospital in Granada (Spain) from 1999 to 2002. Twenty-five patients were viroimmunologically stable, while the other 36 patients had suffered virological failure. A minimum of three blood samples were taken at intervals of at least 3 months for the patients who were stable virologically and immunologically, whereas four samples were taken for the virological failure group: two previous to the onset of virological failure, a third corresponding to the time of virological failure, and a fourth at least 3 months after remission of virological failure. Blood samples were also obtained from 20 healthy control subjects; Hsp70 levels in all were determined by enzyme immunoassay. The mean concentration of Hsp70 was 145.4 ng/ml in the HIV-infected patients as opposed to 72.1 ng/ml in the controls. While the viroimmunologically stable group showed levels similar to those of the controls (66.5 ng/ml), the mean value of Hsp70 in the virological failure group was nearly four times as high (249.1 ng/ml), yet this difference was not statistically significant. The patients treated with reverse transcriptase inhibitors were found to have significantly higher levels of Hsp70 than the other subjects. The transformed variable Hsp70/CD4(+) presents less variability than the Hsp70 value itself, giving a higher degree of statistical significance, and may be considered a useful parameter for diagnostic, prognostic, and therapeutic management of HIV positive patients.

Adult↗

Influence of grain processing on acid-base balance in feedlot steers.

Grain processing (e.g. grinding, steaming, pelleting, flaking) has been reported to modify the incidence of ruminal disturbances in feedlot cattle. This study investigated the effects of two grain processing methods widely used in Spanish feedlots (grinding and pelleting) on animal performance, blood acid-base balance, blood electrolyte levels and serum lactate in a 140-day feedlot experiment with double-muscled Belgian Blue steers. The main aim of the study was to evaluate the way in which these two feeds modify blood acid-base balance, which is closely associated with ruminal pH. In light of our results we conclude that the animals that received the pelleted feed showed a more stable acid-base balance over time than those fed a ground feed. Nevertheless, higher levels of L-lactate and lower base excess (BE) and HCO(3)(-) values for cattle fed pelleted grain reflect a greater risk of grain-acid overload.

Acid-Base Equilibrium↗

CD4+ CD30+ T cells perpetuate IL-5 production in Dermatophagoides pteronyssinus allergic patients.

BACKGROUND: Airway allergic diseases are regulated by interleukin (IL)-5, which causes infiltration of eosinophils into the bronchial epithelium, and by IL-4 which increases serum immunoglobulin E (IgE) production and promotes CD30 expression on Th cells. CD30 generates a costimulatory signal involved in apoptosis or cell proliferation, depending on the microenvironment. Our aims were: (i) to analyze if CD4+ CD30+ T cells from allergic patients proliferate in response to Dermatophagoides pteronyssinus, and (ii) if upon stimulation this cell population produces IL-4 and IL-5. METHODS: Peripheral blood mononuclear cell (PBMC) from 17 allergic rhinitis and mild allergic asthma patients and 12 healthy nonallergic individuals were stimulated with allergen in the presence or absence of anti-IL-4, anti-IL-5 or anti-IL-4Ralpha monoclonal antibodies (mAbs). TdT-mediated dUTP nick end-labeling (TUNEL) assay, 7-aminoactinomycin-D (7-AAD) intercalation, and flow cytometry were used to determine the CD4+ CD30+ blasts percentage, cell proliferation, apoptosis, and intracellular cytokines after 7 culture days. RESULTS: Cell proliferation induced with allergen showed that 90% of the allergen-stimulated blasts were CD4+, 50% of which were CD30+. Allergen-stimulated PBMC showed a progressive increase (mean: from 7% to 23%) of CD4+ CD30+IFN-gamma+ and CD4+ CD30+IL-4+ blasts which diminished (mean: 6%) after 5 culture days. In contrast, CD4+ CD30+IL-5+ blasts showed a continuous progression (from 12% to 24%) that maintained after 7 culture days. The vast majority of CD4+ CD30+ blasts were negative to 7-AAD or TUNEL. Additionally, a significant decrease (34%) was observed in the number of CD4+ CD30+ blasts when IL-4 was neutralized. CONCLUSIONS: These data suggest that specific allergen stimulation of PBMC isolated from allergic patients generates a nonapoptotic CD4+ CD30+ blast subset that produces IL-5.

Adolescent↗

Food-dependent exercise-induced anaphylaxis to pistachio.

We report the case of a 16-year-old male who, 30 minutes after beginning to play football with previous ingestion of pistachio nuts, experienced an anaphylactic reaction. Prick-by-prick test with roasted pistachios was negative. Specific IgE antibodies to pistachio, cashew nuts and mango were negative. An open oral challenge test with pistachio in resting conditions was negative. Treadmill ergonometric stress in a fasting state and 60 minutes after a meal without pistachio gave negative results. A specific food exercise challenge 60 minutes after ingestion of 50 g pistachio nuts was positive, showing mild diffuse erythema and small wheals in face and thorax. To the best of our knowledge, this is the first described case of specific food dependent exercise-induced anaphylaxis to pistachio. Negative allergologic tests is an unusual condition, since most cases appear to be IgE-mediated. In this case, a positive specific food exercise challenge test provided a definite diagnosis.

Adolescent↗

Plasma malonaldehyde (MDA) and total antioxidant status (TAS) during lactation in dairy cows.

Metabolic profiles are widely used to monitor health, reproductive status and nutritional status. In the last few years, the evaluation of oxidative stress has contributed increasingly to our knowledge of the fundamental mechanisms involved in metabolic disorders, especially important in dairy cows, in which lactation imposes great physiological demands on the body's homeostatic mechanisms. The aim of the present study was to evaluate oxidative status in healthy cows during lactation (from lactation onset to peak lactation) using two parameters: (i) plasma levels of malondialdehyde (MDA) and (ii) total antioxidant status (TAS). Our results confirm that nutrition can influence the characteristic metabolic changes occurring between lactation onset and peak lactation. In addition, the combination of MDA and TAS can provide complementary information about the metabolic status of the cow. Thus, the proper metabolic adaptation to the onset of lactation, showed by metabolic profiles, contrasts with the high levels of free radicals which cause lipid peroxidation and high MDA values (68.99+/-33.64 microm/L) which is maintained only for a short period of time. In this moment, the antioxidant system can cope efficiently with lipoperoxide production. The most remarkable fact was the great inter-individual variations observed in MDA that might be studied in further investigations. When the animal reaches peak lactation, metabolic status is stabilized, and this is reflected by antioxidant status with mean values of 28.87+/-5.33 microm/L for MDA and 0.154+/-0.002 mmol/L for TAS values.

Animals↗

Outcome of endoscopic third ventriculostomy. Results from an unselected series with noncommunicating hydrocephalus.

BACKGROUND: Endoscopic third ventriculostomy (ETV) has gained acceptance as the treatment of choice for noncommunicating hydrocephalus despite a relatively high failure rate and a higher surgical risk than the placement of a shunt. The benefits of shunt independence overcome both drawbacks. This argument also serves to consider candidates for ETV patients with a poor chance of success, a fact which may to a certain degree explain failure rates higher than 20% in most unselected series of patients with noncommunicating hydrocephalus. METHOD: From 1997 to 2003 sixty-six patients with suspected noncommunicating hydrocephalus were treated with ETV. Male and female patients were equally distributed. It is an adult-based series (median age 53 years). The etiology of hydrocephalus was a space-occupying lesion in 39 patients (59%) and primary aqueductal stenosis in 27 (41%). Forty-seven patients presented an acute form of hydrocephalus (71%), the remainder presented a chronic form of hydrocephalus. The morbidity and outcome of the procedure were reviewed. Criteria for success was shunt independence and failure was considered when any surgical manoeuvre was further required for the treatment of hydrocephalus. The outcome was evaluated using the Kaplan-Meier survival method. FINDINGS: The probability of remaining with a functioning ETV at 5.7 years (mean follow-up period) is 71.6% (95% confidence interval: 60.5-82.8). Failure occurred in 18 patients (27.3%). If failure occurs, there is a cumulative probability of 90% (95% confidence interval: 84-97) that the failure declares itself during the first 16 days after surgery. There were transient complications in five patients (7.5%), permanent in one (1.5%) and no mortality related to the procedure. CONCLUSIONS: ETV had a 5-year success rate of 71.6% with a low rate of permanent complications. When ETV is successful, the result tends to hold up over time. Delayed failure is a rare event.

Adult↗

The role of metallothionein and zinc in hepatic copper accumulation in cattle.

The role of metallothionein (MT) and zinc (Zn) in hepatic copper (Cu) accumulation in calves from a region in North-West Spain has been investigated. In this region there is intensive pig farming, and animals with liver Cu concentrations above normal are not uncommon. Concentrations of hepatic MT were not related to Cu accumulation but were strongly dependent on the Zn status of the animal. When analysing the metal content bound to MT it was observed that Cu-MT values, in the same way as Zn-MT, were directly correlated with MT concentrations in the liver, indicating that although Cu is a poor inducer of MT synthesis, it can compete with Zn for MT binding sites. The ability of Cu to displace Zn from MT is highly dependent on the Cu:Zn ratio in the cell, Cu being the main metal in MT at the higher levels of Cu exposure in Galician cattle. In spite of this, the percentage of the total hepatic Cu bound to MT is very low in these animals, indicating that cattle have a very limited capacity to accumulate Cu-MT in the liver, and may therefore have a greater susceptibility to Cu toxicosis.

Animals↗

Allergy to sea fishing baits.

We report a new case of rhinitis and asthma caused by sea fishing baits. The results showed exposure to Sipunculus nudus (Phylum Sipuncula; order Sipunculida: Sipunculidae) to be the main cause of the allergic symptoms. The intervention of IgE was demonstrated, with the presence of cross-reactions with allergenic extracts from other worm species used as baits, belonging to different orders of Annelida.

Allergens↗