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Biomedical subjects

G Garcia

Publications and source records attributed to G Garcia.

At least 19 recordsLinked to original sources
PubMed2006

VUV spectroscopy of water under cellular conditions.

The understanding of radiation damage within cells, and thence mutagenesis, depends upon a detailed knowledge of the spectroscopy and dissociation dynamics of water. Results of a new study of the electronic state spectroscopy of water, using synchrotron radiation are reported. In order to gain some insight into how the spectroscopy and dissociation dynamics of water is influenced by its environment we also report photo-absorption spectra of water within thin films of poly(o-methoxyaniline) which have been suggested as a good mimic for biological membranes in the cellular environment. Comparison of these spectra with those of gaseous water and condensed amorphous water ice suggest that water in such films is similar to gaseous water and does not show the blue shift suggested in some cellular models. The lowest energy of OH production from dissociation of water in the cellular environment may therefore be around 6.7 eV (185 nm).

Cell Membrane↗
PubMed2006

Mean values of the LMM Auger transition in a KLM model.

The standardization of radionuclides decaying by electron capture can be carried out in LS counters by the CIEMAT/NIST method. The KLM model considers a simplified atomic rearrangement model in which all L- and M-subshells have been averaged. In this paper, instead of considering the 22 rearrangement pathways of the KLM model, we concentrate our analysis on the pathways corresponding to L-Auger electron transition. It is proved that the counting efficiency depends strongly on the energy E(LMM). Therefore, it is important to know the optimum value for E(LMM) and how to obtain it. To this end, the equations of the probabilities and the reduced energies for 3816 atomic rearrangement pathways have been derived. To average the equations, a computer program called MOYEN has been developed. The energy E(LMM) has been computed for 55Fe and 125I from different mean value definitions.

Algorithms↗
PubMed2006

Influence of target organ lesion detection (assessment of microalbuminuria and echocardiogram) in cardiovascular risk stratification and treatment of untreated hypertensive patients.

European guidelines indicate the importance of the evaluation of global cardiovascular risk (CVR) to determine the management of the hypertensive patients (EH). However, in primary care, the diagnostic work-up (PCD) only includes the metabolic risk factors. The aim of this study was to assess the importance of microalbuminuria (MA) and echocardiogram (ECHO) in the process of risk stratification, and the number of patients to be treated with drugs at diagnosis. In total, 155 nontreated EH were included in the study. Blood pressure, a lipid profile and plasma glucose (LG) were determined after an overnight fast. MA was evaluated with dipstick MICRALTEST, and in those patients with two positive results, it was measured again in two 24-h urine samples and was considered positive (MA+) if the average was >30 mg/24 h. Left ventricular mass index was calculated and values>125 g/m2 were considered as LV hypertrophy (LVH+). When the patients were stratified according to PCD, 22 had to be treated with drugs. When MA, ECHO and both tests used together were added to the risk evaluation, the number of patients to be treated were 42, 51 and 64, respectively (P<0.001 vs PCD). It is mainly in patients who have moderate cardiovascular risk that risk changes, whereas risk hardly changes in those having low and very high risk. In conclusion, in EH with moderate risk, measurement of MA, due to its easy availability and low cost, seems to be a cost effective screening test to avoid the underestimation of the CVR.

Albuminuria↗
PubMed2006

Dexamethasone and IL-10 stimulate glucocorticoid-induced leucine zipper synthesis by human mast cells.

BACKGROUND: Glucocorticoids (GCs) decrease tissue mast cell (MC) number and prevent their activation via their high-affinity IgE receptor. Glucocorticoid-induced leucine zipper (GILZ) is one of the GC-induced genes, which inhibits the functions of the transcriptional activators AP-1 and NF-kappaB. GILZ appears to be a critical actor in the anti-inflammatory and immunosuppressive effects of GCs in human T lymphocytes, macrophages and dendritic cells. AIMS OF THE STUDY: We investigated whether GILZ was produced by human MCs and whether GILZ synthesis was stimulated by GCs. We also investigated whether GILZ production was modulated by (i) IL-10, because of its common immunosuppressive properties with GCs, (ii) histamine because of its pro-inflammatory properties and (iii) IL-4 and IL-5 because of their ability to favour MC survival and proliferation with SCF. METHODS: The human MC lines HMC-1 5C6 and LAD-2, and cord blood-derived MCs (CB-MCs) were cultured alone or in the presence of GCs, IL-10, histamine, IL-4 or IL-5. The expression of GILZ was evaluated by using RT-PCR, Western blotting or immunocytochemistry. RESULTS: We found that human MC lines and CB-MCs constitutively produce GILZ. We also show that GCs and IL-10 stimulate GILZ production by human MCs. Our present results indicate that histamine, IL-4 and IL-5 alone or in combination with SCF do not downregulate GILZ production by MCs. CONCLUSIONS: These results show that GCs and IL-10 stimulate GILZ production by human MCs. As GILZ mediates anti-inflammatory effects of GCs in immune cells, we speculate that GILZ could account for the deactivation of MCs by GCs and IL-10.

Cell Line↗
PubMed2006

The gross anatomy of the male reproductive system of a neotropical rodent: the agouti (Dasyprota leporina).

The literature available on the agouti (Dasyprocta leporina) is very limited. The agouti is a Neotropical rodent found in Trinidad and Tobago, Central and South America. This study focuses on one of the many unexplored areas relating to the species, the male reproductive system. The results showed that the mean testicular length, diameter and weight was 3.67 +/- 0.12 cm, 1.67 +/- 0.04 cm and 5.03 +/- 0.52 g respectively. The paired testes and epididymis were found in contact with the abdominal muscles within scrotal pouches, which are evaginations of the caudoventral abdominal wall. The caput epididymis is enclosed by a fat body. The ductus deferens has a mean length and diameter of 10.98 +/- 0.40 cm and 0.14 +/- 0.01 cm respectively. At the urethral end of the ductus deferens the diameter of each duct expends to form the ampulla. The mean diameter of each of the ampulla was 0.25 cm. The accessory sex organs of the male agouti (D. leporina) include the vesicular glands, the coagulating glands, the prostate glands and the bulbourethral glands. The penis of the agouti is U-shaped with a mean length of 9.90 +/- 0.43 cm. The glans penis contains an os penis, a pair of lateral penile cartilages and paired ventral keratinaceous styles.

Animals↗
PubMed2006

Cleaner production and methodological proposal of eco-efficiency measurement in a Mexican petrochemical complex.

Abstract In the frame of the Petróleos Mexicanos Institutional Program for Sustainable Development, processes were evaluated in the manufacture operation of the petrochemical industry, with the purpose of reducing their ecological fingerprint. Thirteen cleaner production opportunities were registered in six process plants: ethylene oxide and glycols, acetaldehyde, ethylene, high density polyethylene, polypropylene switch and acrylonitrile, and 45 recommendations in the waste water treatment plant. Morelos is the second most important petrochemical complex in the Mexican and Latin American petrochemical industry. A tool was developed to obtain eco-efficiency indicators in operation processes, and as a result, potential savings were obtained based on best performance, as well as the integrated distribution of Sankey diagrams. Likewise, a mechanism of calculation to obtain economic savings based on the reduction of residues during the whole productive process is proposed. These improvement opportunities and recommendations will result in economic and environmental benefits minimising the use of water, efficient use of energy, raw materials and reducing residues from source, generating less environmental impacts during the process.

Acetaldehyde↗
PubMed2005

A randomized non-crossover study comparing the ProSeal and Classic laryngeal mask airway in anaesthetized children.

BACKGROUND: We tested the hypothesis that ease of insertion, oropharyngeal leak pressure, fibreoptic position, gastric insufflation, and the frequency of mucosal trauma differ between the ProSeal laryngeal mask airway (PLMA) and the classic laryngeal mask airway (cLMA) in anaesthetized children. For the PLMA, we also assessed the ease of gastric tube placement via the PLMA drain tube and measure residual gastric volume. METHODS: 240 consecutive ASA I-III children aged 1-16 yr were randomized for airway management with the ProSeal or cLMA. RESULTS: The time taken to provide an effective airway, the number of insertion attempts, fibreoptic position of the airway tube and frequency of mucosal trauma were similar, but oropharyngeal leak pressure was higher (33 vs 26 cm H(2)O, P<0.0001) and gastric insufflation less common (0 vs 6%, P<0.01) for the PLMA. Gastric tube insertion was successful at the first attempt in 106 of 120, and at the second attempt in 14 of 120. The mean (sd; range) value for residual gastric volume was 2.2 (5.9; 0-30) ml. There were no differences in performance among sizes for the PLMA and the cLMA. CONCLUSIONS: We conclude that ease of insertion, fibreoptic position, and frequency of mucosal trauma are similar for the PLMA and cLMA in children, but oropharyngeal leak pressure is higher and gastric insufflation less common for the PLMA. Gastric tube insertion has a high success rate, provided the PLMA is correctly positioned.

Adolescent↗
PubMed2004

Effect of an EGF-cancer vaccine on wound healing and inflammation models.

BACKGROUND: Epidermal growth factor (EGF) and its receptor (EGF-R) are attractive targets for cancer immunotherapy. Tolerance has been broken with an EGF-vaccine and antibodies against EGF have been produced in animals and in cancer patients. EGF also plays an important role in the inflammation stage of wound healing. Because this therapeutic approach may be of importance after surgery procedures in cancer patients, we decided to investigate the possible role of the EGF-vaccine in the croton-oil-induced ear edema and in the wound healing experimental animal models. MATERIALS AND METHODS: Mice were immunized with an EGF-vaccine by intramuscular injections and serum titers against EGF were measured through ELISA techniques. Control animals received saline. RESULTS: Immunized mice produced antibodies against EGF while no antibody titers could be measured in control animals. Croton oil applied to the inner ear surface of EGF-vaccine treated mice caused a 61.3% lower ear punch weight and a 60.2% lower myeloperoxidase activity than control mice. In the EGF-vaccine treated animals, planimetry measurements and histological analysis did not led to significant impairment in tissue repair. CONCLUSIONS: The EGF-vaccination in mice decreased the normal croton-oil-induced inflammation response, without apparent impairment in tissue healing.

Animals↗
PubMed2004

Study of tyrosine hydroxylase immunoreactive neurons in neonate rats lactationally exposed to 2,4-dichlorophenoxyacetic Acid.

Dopaminergic neurons from the midbrain nuclei substantia nigra (SN; A9) and ventral tegmental area (VTA; A10) were investigated by tyrosine hydroxylase (TH) immunostaining in neonate rat brains exposed to 2,4-dichlorophenoxyacetic acid (2,4-D) through lactation. Dorsal raphe serotonin (5-HT) projections to SN and VTA were also studied by 5-HT transporter (5-HTT) immunostaining and results were quantified by image analysis. Twenty-five-day-old pups exposed to 2,4-D through mothers milk were used. Dams were intraperitoneally administered 70 or 100mg/kg/day of 2,4-D from the 9th to the 25th postpartum day. After 100mg/kg of 2,4-D exposure, a 25% diminution in the SN and a 33% diminution in the VTA neurons' TH immunostaining along with a significantly 5-HT fiber density diminution were observed. The present work supports previous reports which suggest that exposure to 2,4-D during development has multiple effects on CNS.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2004

[Potential sexual consequences associated with benign prostatic hyperplasia and its treatments].

In this article, an updated review of the potential consequences of treatment of benign prostatic hyperplasia (BPH) on sexual function is proposed in the light of recent data. Differences exist between the different therapeutic options available for the treatment of lower urinary tract symptoms (LUTS) when we want to analyze the impact on sexuality. Surgical procedures including minimally invasive techniques are associated with ejaculation and also erection disorders. Drug treatments also have repercussions on sexuality though there are significant differences between the various classes of these drugs. In daily practice, the relation between the prostate and sexuality must be assessed during any medical examination for one of these diseases and before any decision on treatment.

Humans↗
PubMed2004

Monitoring recovery after injury: procedures for deriving the optimal test window.

Researchers studying the impact of treatments designed to facilitate recovery after neural injury face competing demands. On the one hand, because treatment effects often emerge slowly over days, and because researchers seek evidence of stable long-term effects, it is common practice to observe experimental subjects for many weeks after treatment. On the other hand, the cost of performing studies and the need to evaluate a multitude of alternative treatment procedures requires optimal efficiency, pushing researchers towards shorter test procedures. With these issues in mind, researchers have appeared to derive a test window based on previously published methodologies and inspection of their recovery curves, with testing terminated after the recovery curve reaches asymptote (approaches a slope of 0). An alternative procedure is introduced here that evaluates the stability of the data set over time. Using correlational techniques, researchers can determine whether (1) testing should be continued for additional days; or (2) equivalent statistical power can be achieved in fewer days. This provides a rational decision rule to help researchers balance competing demands. Applying these techniques to a procedure that evaluates the impact of acute treatments on recovery from spinal cord injury, it is shown that equal statistical power can be achieved in half the time, greatly increasing the efficiency with which alternative treatments can be evaluated.

Animals↗
PubMed2003

[Pulmonary artery hypertension associated with connective tissue diseases].

MOST IMPORTANT: Pulmonary hypertension (PH) is a severe, potentially life-threatening complication of connective tissue diseases, among which scleroderma is first line. The aim of this paper was to review the literature and report our experience with this particular complication of connective tissue diseases. In our centre of pulmonary vascular diseases, connective tissue diseases represent the third cause of PH. RESULTS: Scleroderma and particularly its limited cutaneous variant, the CREST syndrome, is the most common connective tissue disease affected by pulmonary hypertension. It can be related to a specific lung parenchymal involvement (hypoxic PH), to an isolated pulmonary vascular involvement or to a cardiac dysfunction secondary to specific myocardial lesions. DIAGNOSIS: Echocardiography is an excellent examination to detect pulmonary hypertension. However, right heart catheterisation is necessary to confirm the diagnosis of pulmonary hypertension and to test vasoreactivity with a potent vasodilator such as nitric oxide (NO). REGARDING TREATMENTS: Oral calcium channel blockers are indicated in patients who are responders to acute NO tests. Treatment with continuous intravenous prostacylin is obviously an improvement, at least functionally, although it appears less effective than in primary PH. With the new subcutaneous, oral and inhaled vasodilatators (prostaglandin and endothelin receptor antagonists), a few cases of improvement of PH with intensive immunosuppressive therapy were observed, essentially during systemic lupus erythematosus and Sharp syndrome. IN PRACTICE: PH is a severe complication of connective tissue diseases. Early detection of this complication should allow an earlier and more aggressive therapeutic approach in these patients, before irreversible vascular lesions occur.

Adult↗
PubMed2003

[Pulmonary hypertension complicating systemic diseases other than connective tissue diseases].

A COMPLICATION OF CERTAIN SYSTEMIC DISEASES: Pulmonary hypertension (PH) can complicate the progression of certain systemic diseases such as sarcoidosis, histiocytosis X and some vasculites. The mechanisms at the origin of PH are varied and always require rigorous analysis in order to optimise treatment. DEPENDING ON THE DISEASE: PH associated with sarcoidosis is essentially related to specific lung parenchymal fibrosis and is poorly responder to corticosteroids. Other mechanisms may be more rarely incriminated (compressive andenopathies, mediastinal fibrosis, florid sarcoidosis concomitant to a pulmonary occlusive vascular disease...). During histiocytosis X, the ventilatory limitation of these patients does not always correlate with the severity of the respiratory failure, suggesting the existence of a pulmonary vascular disease progressing independently of the pulmonary parenchymal lesions. The pulmonary artery damage during Takayasu's arteritis and other auto-immune pulmonary arteritis may lead to potentially life-threatening complications, notably through stenosis and/or obstruction of the pulmonary arteries. Pulmonary hypertension is exceptional during Wegener's disease or periateritis nodosa. CONCLUSION: PH can complicate the progression of certain systemic diseases. The physiopathological mechanisms responsible are unclear (specific parenchymal fibrosis, isolated vascular involvement...). Globally, available treatments are disappointing.

Cardiac Catheterization↗
PubMed2003

Difficult asthma.

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Anti-Asthmatic Agents↗
PubMed2003

Evaluation of CD4+ T cells proliferating to grass pollen in seasonal allergic subjects by flow cytometry.

Our objective was to characterize T-cell responses to Phleum pratense in grass pollen allergic individuals and healthy controls using the fluorescent dye PKH26. Peripheral blood mononuclear cells were stimulated with P. pratense, or with recall antigens, and CD3+/CD4+ and CD3+/CD8+ T-cells that had proliferated were analysed by flow cytometry. In the presence of P. pratense CD4+/CD3+ T-cells proliferated more in grass pollen sensitive atopic patients than in nonallergic controls or in nongrass pollen sensitive atopic subjects. PPD and TT recall antigens elicited uniformly high proliferation in all T-cell subsets. Only half of pollen sensitive patients also had an increased proliferation of CD3+/CD8+ T-cells in response to P. pratense. We determined precursor frequency of CD4+ T cells in the original population that responded to P. pratense and found values ranging from 1 x 10-3 to 0.6 x 10-1, in the same range as those measured for PPD and TT. In conclusion, grass pollen sensitive atopic patients show enhanced CD4+ T-cell reactivity to P. pratense, and this could be related to the presence of elevated numbers of circulating allergen-specific CD4+ T cells. This flow cytometric method should allow the identification of other phenotypic markers such as intracellular cytokines in allergen specific responding CD4+ T cells.

Allergens↗
PubMed2003

Hypogalactosylation of serum IgG in patients with coeliac disease.

Coeliac disease (CD) is described as an autoimmune enteropathy associated with the presence of IgG and IgA antigliadin and antitransglutaminase autoantibodies. While of diagnostic significance, the role of these autoantibodies in the immunopathogenesis of CD is elucidated. An inappropriate T cell immune response to gluten is also involved in the pathogenesis of CD, as evidenced by autoantibody switching. The N-glycans released from serum IgG of CD patients and three groups of healthy controls, of differing age ranges, were analysed by NH2-high performance liquid chromatography (HPLC). The fucosylated biantennary N- glycans were the most abundant neutral oligosaccharides; in particular, the agalacto form (G0F) showed a mean value of 42% (s.d. +/- 7.4), 30% (s.d. +/- 5.9), 26% (s.d. +/- 4.2) and 35% (s.d. +/- 6.8) for CD patients, healthy children, healthy adults under 40 and healthy adults over 40 years old, respectively. The ratio of asialo agalacto fucosylated biantenna to asialo monogalacto fucosylated biantenna (G0F)/(G1F) for CD patients showed a significant increase compared to healthy children (P < 0.0002), healthy adults under 40 (P < 0.0002) and healthy adults over 40 years old (P < 0.01). Hypogalactosylation was more pronounced for CD patients than for the patients with other autoimmune diseases such as rheumatoid arthritis or psoriatic arthritis.

Adult↗