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Biomedical subjects

H García

Publications and source records attributed to H García.

At least 19 recordsLinked to original sources
PubMed2006

Characterisation of solid and liquid fractions of dairy manure with regard to their component distribution and methane production.

Dairy manure with a total solids content of 77.2g TS/l was separated by means of screening and coagulation-flocculation treatments, using CaO as coagulant and a cationic polyacrylamide as flocculant, obtaining liquid and solid fractions. The solid fraction separated contained 33.4% of the initial total mass of dairy manure plus chemical solutions, containing also 75.2% of the TS, 80.4% of the VS, 58.5% of the total Kjeldahl nitrogen (TKN) and 87.4% of the total phosphorus (P(T)) present in the initial dairy manure. 83.7% of the liquid fraction chemical oxygen demand (COD) was anaerobically biodegradable (COD(BD)). Methane production for the separated liquid fraction was 0.604l CH4 NCTP/g VS added, being 0.307 and 0.371l CH4 NCTP/g VS added for dairy manure and screened dairy manure, respectively. The characteristics of this liquid fraction would allow its treatment in high loading anaerobic reactors having shorter hydraulic retention times, smaller reactor size and a higher methane volumetric production rate than conventional anaerobic reactors treating either manure or screened manure.

Anaerobiosis↗
PubMed2006

Two-factor design for coagulant/flocculant doses effect for solid-liquid separation of dairy manure.

Screened dairy manure, with a total solids content equal to 34.7 g TS l(-1), was subjected to a coagulation-flocculation treatment using FeCl, as coagulant and a medium cationic polyacrylamide (MCP1). The effect of changing doses of the additives (FeCl3 and MCP1) on the properties of supernatant fractions was studied by means of design of response surface using "Statgraphics Plus 3.0" program. The results showed that the values of concentrations found in supernatants obtained after settling of the flocs for two of the dependent variables studied, filtrate chemical oxygen demand (CODf) and total organic carbon (TOC), were significantly influenced by both the FeCl3 and MCP1 doses at an error lower than 5%. The values of concentrations of the remaining variables studied (TS, VS, CODt, CODvfa) were significantly influenced only by the MCP1 dose at an error lower than 5%. The predictive model obtained the best satisfactory parameters for TOC supernatant's concentration (R2=0.980, F-ratio = 438.89 (p-value < 0.05)) and the worse for VS (R2 = 0.783, F-ratio = 33.43 (p-value < 0.05)).

Acrylic Resins↗
PubMed2006

Perinatal/postnatal study of D-003, a mixture of long-chain fatty acids, in rats.

D-003 is a mixture of long-chain fatty acids isolated and purified from sugar cane wax with cholesterol-lowering and antiplatelet effects. In order to further characterize the developmental toxicity during the treatment period from late gestation up to weaning of the offspring, pregnant females received 0 (control), 500, and 1,000 mg/kg/day D-003 daily by oral gavage beginning at day 15 of pregnancy and through gestation until day 21 postpartum. Maternal clinical signs, body weight, and food intake were measured at regular intervals during gestation and lactation. Live pups were weighed, sexed, and examined for developmental signs. One female and male of each litter were randomly selected to evaluate the reproductive potential. There were no spontaneous or dose-related maternal deaths during the course of this study. The general health and behavioral condition of offspring was good in all groups. No significant differences among groups were found in comparisons of litter size, survival through the weaning period, sex ratio, and male and female weights. This peri- and postnatal study conducted with D-003 in rats indicated that treatment of the dam during late gestation and lactation did not show adversely effects on reproductive performance or fetal development over two generations.

Animals↗
PubMed2006

Trypanosomiasis in Venezuelan water buffaloes: association of packed-cell volumes with seroprevalence and current trypanosome infection.

The seroprevalence of trypanosomiasis and the prevalence of current trypanosome infection in water buffaloes from the most important livestock areas of Venezuela were evaluated by IFAT and the microhaematocrit centrifugation technique, respectively. The usefulness of a PCR-based assay for identifying the trypanosome species in the buffaloes was also evaluated. Of the 644 animals investigated, 40 (6.2%) were found infected with trypanosomes by blood centrifugation, and 196 (30.4%) were found positive for anti-trypanosome antibodies, by IFAT. The results of the PCR-based assay indicated that 92.5% of the animals with current infections were infected with Trypanosoma vivax and the rest with T. theileri (the first molecular confirmation of T. theileri in Venezuelan water buffaloes). The national programme to treat and prevent trypanosome infections in the buffaloes does not appear to be meeting with great success, even though it is focused on T. vivax. Although the level of parasitaemia was categorized as low for 28 (70%) of the infections detected (and packed-cell volumes appeared to be unassociated with IFAT result, and uncorrelated, in the infected animals, with level of parasitaemia), the 40 infected buffaloes had a significantly lower mean packed-cell volume than the uninfected animals (P<0.05). Farmers should therefore be made aware of the probability of trypanosome-attributable losses in buffalo productivity.

Animals↗
PubMed2006

[Estimation of the cost in the farmacologic treatment of chronic renal failure].

The prevalence and incidence of end stage renal disease has increased considerably in the past years. We know that the cost of treatment of these patients is high. Limited information exists on care resource utilization for maintenance of patients before the initiation of replacement therapy. The purpose of this study is determine the cost of pharmaceutic treatment during the predialysis phase. Pharmacy cost was analyzed for 200 patients controlled on outpatient nephrology department. The mean age was 72.4 years, 59% were males, and the comorbidity distribution was: hypertension 87%, hyperlipidemia 56% and diabetes 35%. The per-patient-per-month charges were 215.45 Euro, with a continous increase from 84.64 Euro on stage 1 to 352.59 Euro on stage 5 of chronic kidney disease. Erythropoiesis stimulants were reponsible of 46.5% of these cost. The most frequent prescribed medications were antihypertensive drugs, statins and iron preparations. Patients with end stage renal disease generate significant cost during the predialysis period. The limited resources, and the growth of health care expeditures, particulary the spending for prescriptions drugs, are two of the major problems for Health Care Systems. A better knowledge of the associated costs to the treatment of these patients will help us to increase our efficiency.

Aged↗
PubMed2005

Effect of ME-3451-106, an aqueous extract of Stichaster striatus with inhibitory activity of voluntary alcohol intake, in genetically drinker rats: Isolation and identification of the active fraction.

The aqueous extract obtained from Stichaster striatus Müller & Troschel (Asteroidea, Stichasteridae) has been shown to possess activity as an alcohol appetite inhibitor after oral administration in a rat model with a genetically established excessive appetite for alcohol (Wistar rats, lineage UChB). A significant decrease in the consumption of ethanol was observed (unrelated to a possible disulfiram effect) without a change in the normal food or water intake during the experimentation period. A bio-guided fractionation of the extract was carried out in order to identify the most active fraction, in which the presence of a group of natural endogenous polyamines in undetermined proportions is suspected. Our hypothesis was to relate the activity obtained for the original ME-3451-106 extract with the presence of these polyamines in the extract in question. The activity shown by a series of commercially available polyamines (putrescine (Pu), spermidine (SPD) and spermine (SP)) in inhibiting voluntary ethanol intake lends support to our hypothesis. The extract was selected on the basis of oral tradition, which claimed that the consumption of a "soup" obtained by boiling starfish, later identified as Stichaster striatus, prevented the appearance of alcoholism in laborers on properties entrusted to the Jesuit order during the middle period of the Spanish conquest of America (17-18th century).

Alcohol Deterrents↗
PubMed2005

Process development for a Cuban cholera vaccine based on the attenuated strain Vibrio cholerae 638.

Genetically modified Vibrio cholerae strain 638 (biotype El Tor, serotype Ogawa) has previously been shown to be immunogenic in animal models and in human trials. Our objective in the work reported herein was to describe the process development methods for the production of the 638 attenuated cholera vaccine. Cell seed bank, culture of biomass, lyophilization and final formulation were processes were developed. The results show kinetics of culture that fulfils a logistical model. The microbiological properties, colonizing capability, immunogenicity and non-toxigenicity of the final product were indistinguishable from the properties of the working seed lot. We conclude that the non-reactogenic, immunogenic and protective strain 638 is robust and can withstand the fermentation processes required for large-scale production of a vaccine.

Animals↗
PubMed2005

Effect of acute sublethal endotoxaemia on in vitro digital vascular reactivity in horses.

Endotoxaemia is a syndrome linked to the development of equine laminitis; however, the relationship between them is uncertain. The aim of this experiment was to evaluate the effect of an experimental acute sublethal endotoxaemia model on in vitro equine palmar digital vascular reactivity. Rings of arteries and veins of each forelimb were obtained from 11 clinically healthy horses submitted to two surgical procedures, 3 weeks apart. Before the second surgery, 0.25 microg/kg of lipopolysaccharide from Escherichia coli O55:B5 in saline, was administered i.v. in 30 min. After 3 h, the vessels were harvested and submitted to in vitro vascular reactivity experiments and histopathology. The response to depolarizing Krebs solution (DKS, 40 mm), phenylephrine (PHE), acetylcholine (ACh) and sodium nitroprusside (SNP) were evaluated. All horses showed colic pain and watery diarrhoea, tachycardia, tachypnea, hyperthermia and leucopenia. Concentration-response curve (CRC) to PHE was shifted to the left in arteries rings from endotoxemic horses without any effect on vein rings. The CRC to ACh was shifted to the right with a reduction in the maximal response. The response to SNP and DKS was similar between groups. There was no evidence of histopathological effects. The increased response to PHE in digital arteries together with a reduction of the endothelium-dependent response to ACh in arteries and veins, confirm the existing reports where endotoxaemia was found to modify the digital vascular reactivity during the acute phase. As the digital endothelial function is impaired, there may be an increased potential to develop a digital prothrombotic state with a reduced vasodilatory capacity.

Acute Disease↗
PubMed2005

Oral acute and subchronic toxicity of D-004, a lipid extract from Roystonea regia fruits, in rats.

D-004 is a lipid extract obtained from Cuban royal palm (Rosytonea regia) fruits, consisting of a mixture of fatty acids and esters. D-004 has shown protective effects on prostate hyperplasia induced by testosterone in rodents. We report the results of two studies investigating the acute and subchronic oral toxicity of D004 in rats. Oral acute toxicity of D-004 (2,000 mg/kg) was investigated in Sprague Dawley rats according to the acute toxic class method, and the results showed that D-004 oral acute toxicity was practically absent, being defined as unclassified. In the subchronic study, rats were orally treated with D-004 at 500, 1,000 and 2,000 mg/kg for 90 days. No evidence of treatment-related toxicity was detected. Thus, analysis of body weight gain, clinical observations, blood biochemistry, hematology, organ weight ratios and histopathological data did not show significant differences between control and treated groups. We conclude that D-004 orally administered to rats was safe and that no drug-related toxicity was detected even at the highest dose investigated in both acute and subchronic (2,000 mg/kg) studies. Thus, this dose can be considered as a nonobservable-effect dose in rats.

Administration, Oral↗
PubMed2004

Evaluation of the reproductive and developmental toxicity of the D-003, a mixture of long-chain fatty acids, in rats and rabbits.

D-003 is a mixture of long-chain fatty acids isolated and purified from sugar cane wax with cholesterol-lowering properties. D-003 given orally (500 and 1000 mg/kg/day) to female rats for 15 days prior to mating, through mating and gestation to day 21 of lactation and male rats for 4 weeks prior and during mating did not induce toxic effects on reproduction. There were no significant reductions in the number of animals that conceived, in the numbers of pups born to those that did conceive, in the numbers of pups that survived until weaning, and in their body weights at weaning. Drug-treated and control groups' offspring were comparable in growth, physical and behavioral development, spontaneous activity and reproductive performance. Pregnant New Zealand rabbits were given D-003 as oral doses of 500 and 1000 mg/kg/day on days 6 through 18 of gestation without any evidence of embryotoxicity or teratogenicity. The no-observed-effect dose in these two experimental studies was 1000 mg/kg/day. After assessment of the potential of high doses of D-003 to act on developing embryo and reproduction process, no evidence supports the conclusion that D-003 is a reproductive and developmental toxicant/teratogen.

Animals↗
PubMed2004

[Acute interstitial nephritis associated with omeprazole therapy].

From 1 to 3% of acute renal failures are due to acute interstitial nephritis (AIN). Most of them are due to drugs. Nonsteroidal antiinflammatory drugs, penicillins and sulfonamides are the most frequently reported. Clinical presentation of drug-induced AIN has changed over time and with the use of new drugs. In fact actually the classic triad of fever, rash and eosinophilia is uncommon. Omeprazole is a drug widely used in the treatment of gastroesophageal reflux disease and peptic ulcer disease. Serious side effects are rare with this drug, but despite of its safety we can see serious adverse effects such as acute renal failure. We describe two cases of acute interstitial nephritis after use of omeprazole and a review of all the cases published in the last years.

Acute Disease↗
PubMed2004

Effects of chronic administration of D-003, a mixture of sugar cane wax high molecular acids, in beagle dogs.

D-003 is a mixture of high molecular weight aliphatic primary acids purified from sugar cane wax (Saccharum officinarum, L) with cholesterol-lowering and antiplatelet effects. Previous studies, including a 6-month study conducted in rats, have shown no D-003-related toxicity. The present study was undertaken to investigate the effects of D-003 orally administered for 9 months in beagle dogs. The animals were randomly distributed in three groups: a control group receiving the vehicle only and two groups orally administered D-003 (200 and 400 mg/kg). Body weight gain, food consumption and clinical signs were controlled throughout the study. The effects of D-003 on collagen-induced platelet aggregation, bleeding time (BT) and coagulation parameters (prothrombin time and kaolin-activated thromboplastin time) were also investigated. Most blood biochemistry and hematological parameters were assessed at baseline and after 6 and 9 months of treatment, while total cholesterol (TC), triglycerides, platelet aggregation, BT and coagulation parameters were determined at baseline and after 9 months of treatment. At study completion, the animals were sacrificed. D-003 at a dose of 200 and 400 mg/kg significantly reduced TC (p < 0.05), significantly inhibited platelet aggregation and increased BT compared with levels in controls. Data analyses of body weight gain, food consumption, clinical observations, the remaining blood biochemistry and hematology indicators (including coagulation parameters, organ weight ratios and histopathological findings) showed no trends with D-003 doses or significant differences between control animals and treated groups. In conclusion, D-003 administered for 9 months to beagle dogs induced the expected effects with no evidence of drug-related toxicity.

Administration, Oral↗
PubMed2003

Lack of developmental toxicity of D-003: a mixture of long-chain fatty acids in rats.

D-003 is a mixture of long-chain fatty acids isolated and purified from sugar cane wax, the major component of which is 1-octacosanoic acid and which possesses effective antiplatelet, antithrombotic and cholesterol-lowering effects. D-003 was suspended in 1% acacia gum solution, and given daily by gavage to rats at dose levels of 5, 100 and 1000 mg/kg/day on days 6 through 15 of gestation. Cyclophosphamide, serving as a positive control, was given at the dose of 50 mg/kg/day on day 15 of gestation. Evidence of maternal or developmental toxicity was not observed in the groups treated with D-003. Maternal clinical signs of toxicity were not observed and the analysis of initial body weight and the body weight gain during the treatment period was comparable among the groups treated with D-003 and control. As expected, cyclophosphamide caused both embryotoxic and teratogenic effects in rats. Meanwhile, no adverse effects on reproductive performance, or on embryonic or fetal development, including visceral and skeletal examination, were seen in any of the groups administered D-003. It is concluded that D-003 administered up to 1000 mg/kg/day did not induce any evidence of developmental toxicity.

Abnormalities, Drug-Induced↗
PubMed2002

2,4,6-triphenylpyrylium ion encapsulated into zeolite Y as a selective electrode for the electrochemical determination of dopamine in the presence of ascorbic acid.

2,4,6-Triphenylpyrylium ion immobilized inside the supercages of zeolite Y enhances by 1-2 orders of magnitude the response of electrochemical oxidation of dopamine in neutral aqueous media accompanied by a remarkable inhibition of post-electron-transfer reactions. The negative charge of the zeolite framework in which the 2,4,6-triphenylpyrylium ion is incorporated blocks the electrochemical oxidation of the negative ascorbate ion, enabling the determination of micromolar concentrations of dopamine in the presence of a large excess (10(3)-10(4) times) of ascorbate in phosphate buffer (pH 7.4). Under optimized conditions, linear calibration plots were obtained for a differential pulse detection mode over the range 250-1 microM dopamine with a sensitivity of 62 nA/microM and a detection limit (S/N = 3) of 0.2 microM in the presence of 1.0 mM ascorbate.

Ascorbic Acid↗
PubMed2002

[Peritoneal anionic transfers and their relationship with peritoneal transport and acid-base status].

This study was designed to assess lactate and TCO2 transfers during PET and in 24-hour drained dialysate, relating them with the membrane transport type and acid-base status. Forty PETs were studied, performed in 23 clinically stable patients maintained on CAPD for 6.5 +/- 3 months using 35 mEq/l of lactated-based dialysate. No significant changes in plasma concentration of lactate and TCO2 were observed. Lactate gain (LG) was 51.91 +/- 4.86 and 220.82 +/- 22.61 mEq and TCO2 loss was 46.49 +/- 6.9 and 183.51 +/- 32.9 mEq during PET and 24 h respectively. When analyzed these transfers according to membrane transport characteristics (High/High-average group: HHAG and low/low-average group: LLAG), LG was significantly higher (53.94 +/- 3.7 vs 48.86 +/- 4.8 mEq during TEP p < 0.01, and 228.06 +/- 15.6 vs 209.96 +/- 27.2 mEq during 24 h p < 0.05). TCO2 loss was greater (48.66 +/- 7.15 vs 43.25 +/- 5.5 mEq p < 0.05 and 187.22 +/- 27.3 vs 177.93 +/- 35.3 during PET and 24 h respectively) in HHAG vs LLAG. When evaluating transfers according to patients' acid-base status (normal and acidotic group), no significant differences were found in LG, but there was a significant difference in TCO2 loss (47.7 +/- 5.9 vs 39.76 +/- 6.1 mEq p < 0.01). We did not observe significant differences in acid-base balance during PET according to membrane transport characteristics (HHAG vs LLAG). However, acid-base balance was more positive in acidotic patients' PET than in normal patients (9.87 +/- 6.6 vs 3.92 +/- 6.8 mEq p < 0.05). TCO2 loss during PET directly correlated with plasma TCO2 concentration pre-PET (r: 0.43, p < 0.01). However no significant correlation was found between plasma lactate levels and lactate gain during PET. In conclusion, the lactate gain and bicarbonate loss account for the net dialytic base balance during PET and 24 h. However, the peritoneal membrane transport characteristics as well as the acid-base status can determine a higher or lower aionic transfer (lactate and bicarbonate).

Acid-Base Equilibrium↗
PubMed2001

Characterization of germanium site distribution in zeolite ITQ-7 by photoluminescence.

Zeolite ITQ-7 containing germanium emits luminescence upon excitation at the wavelength of the absorption maxima; control experiments with amorphous GeO2 and all-silica zeolites indicate that the emission is attributable to Ge atoms occupying framework positions; the emission decays on the nanosecond time scale and it fits to variable proportions of three exponential kinetics, this being compatible with the presence of three families of Ge atoms in the solid.

Journal Article↗
PubMed2001

First molecular switch encapsulated within the cavities of a zeolite. A dramatic lifetime increase of the charge-separated state.

A [2]-catenane consisting of a bipyridinium cyclophane and a dioxybenzene macrocyclic polyether has been encapsulated within the supercages of zeolite Y by ship-in-a-bottle synthesis; laser flash photolysis reveals that the charge-separated species decays in hundreds of microseconds in contrast to the few picoseconds previously reported for the same transient in acetonitrile.

Journal Article↗