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María Gómez

Publications and source records attributed to María Gómez.

17 recordsLinked to original sources
PubMed2006

Antimicrobial activity of tigecycline against clinical isolates from Spanish medical centers. Second multicenter study.

The antimicrobial activity of tigecycline, a novel glycylcycline, was evaluated against 1102 bacterial isolates from 20 centers in Spain. The MIC of tigecycline at which 90% (MIC(90)) of the pneumococci tested were inhibited was the lowest (0.06 microg/mL) of all the antibiotics tested. The MICs of tigecycline against enterococci ranged from 0.03 to 0.125 microg/mL. All staphylococci were inhibited by < or =0.25 microg/mL of tigecycline, and 99.6% of Enterobacteriaceae isolates were inhibited by < or =2 microg/mL of tigecycline. Tigecycline demonstrated good activity against Bacteroides fragilis group organisms with an MIC(90) of 4 microg/mL. The results of this study confirm the excellent activity of tigecycline against multiresistant Gram-positive and Gram-negative pathogens.

Anti-Bacterial Agents↗
PubMed2006

Comparative in vitro activity and the inoculum effect of ertapenem against Enterobacteriaceae resistant to extended-spectrum cephalosporins.

The in vitro activity and the inoculum effect of ertapenem were evaluated against a total of 70 Enterobacteriaceae isolates resistant to extended-spectrum cephalosporins. The extended-spectrum beta-lactamase phenotypic confirmatory disk diffusion test was performed and AmpC-inducible species were detected using cefoxitin/cefotaxime disk antagonism tests. beta-Lactamases were characterised by isoelectric focusing and TEM-specific polymerase chain reaction. Minimum inhibitory concentrations (MICs) were determined by the National Committee for Clinical Laboratory Standards agar dilution method. Ertapenem showed excellent activity against almost all isolates tested, with MIC(50) and MIC(90) values of 0.03 mg/L and 0.12 mg/L, respectively. When the inoculum was increased 100-fold, susceptibility decreased from 98.6% to 65.7% for cefepime and from 75.7% to 54.3% for piperacillin/tazobactam, without changing for ertapenem. The data from this study suggest that this new carbapenem may be useful for treating mixed infections involving Enterobacteriaceae isolates resistant to third-generation cephalosporins.

Anti-Bacterial Agents↗
PubMed2006

[Antimicrobial resistance surveillance: VIRA STUDY 2006].

INTRODUCTION: The objective of this study was to determine the current antimicrobial susceptibility patterns of the most frequent multi-resistant bacteria and to analyze any possible changes with respect to the two VIRA studies carried out in 2001 and 2004. METHODS: In February 2006, the 40 participating hospitals sent the following microorganisms: non-penicillin-susceptible Streptococcus pneumoniae (92), methicillin-resistant Staphylococcus aureus (MRSA) (290), clinically significant coagulase-negative staphylococci (136), ampicillin-resistant Enterococcus faecium (89), ampicillin-resistant Haemophilus influenzae (67), ciprofloxacin-resistant Escherichia coli (365), Pseudomonas aeruginosa (181), and Acinetobacter baumannii (92). The hospitals provided epidemiological data on these microorganisms. Susceptibility was determined with a broth microdilution method. RESULTS: Among the non-penicillin-susceptible S. pneumoniae isolates, the proportion of those ones resistant to this antibiotic showed a significant (p < 0.001) decrease (59.8% in 2001, 30.2% in 2004 and 14.3% in 2006). Among MRSA, we detected one isolate nonsusceptible to linezolid, four resistant to quinupristin-dalfopristin and one strain with a vancomycin MIC of 4 microg/mL. The prevalence of extended-spectrum beta-lactamase-producing E. coli was 12.1%. Resistance of A. baumannii to imipenem varied from 27% in the 2001-2004 period to 47.8% in 2006 (p < 0.005). CONCLUSION: These results again emphasize that resistance surveillance systems are an important tool for preventing the emergence and spread of multi-resistant pathogens.

Acinetobacter baumannii↗
PubMed2005

Changing patterns of fluoroquinolone resistance among Bacteroides fragilis group organisms over a 6-year period (1997-2002).

The evolution of susceptibility to the newer fluoroquinolones, moxifloxacin and trovafloxacin, of Bacteroides fragilis group organisms isolated in our hospital from 1997 to 2002 was studied. A total of 927 strains were included in the study. Trovafloxacin was more active than moxifloxacin against the various species of the group. During the study period, an increase in resistance to both quinolones was observed. Rates of resistance to moxifloxacin at a breakpoint of 8 microg/mL remained stable at around 6% during the period 1997-1998 and increased to 11.4% in 2000 and to 16.5% in 2001-2002 (P<0.005). Resistance to trovafloxacin rose significantly from 0.6% in 1998 to 6.8% in 1999 (P<0.05) and did not change appreciably over the last 3 years studied. This study confirms the increasing resistance of B. fragilis group organisms to trovafloxacin and moxifloxacin and emphasizes the need to perform periodic antimicrobial susceptibility tests to guide the selection of appropriate antimicrobial therapy.

Anti-Infective Agents↗
PubMed2004

Heterochromatin on the inactive X chromosome delays replication timing without affecting origin usage.

DNA replication origins (ORIs) map close to promoter regions in many organisms, including mammals. However, the relationship between initiation of replication and transcription is not well understood. To address this issue, we have analyzed replication timing and activity of several CpG island-associated ORIs on the transcriptionally active and silent X chromosomes. We find equivalent ORI usage and efficiency of both alleles at sites that are replicated late on the inactive X chromosome. Thus, in contrast to its repressive effect on transcription, heterochromatin does not influence ORI activity. These findings suggest that the relationship between sites of transcription and replication initiation at CpG island regions is restricted to early development, and that subsequent gene silencing and heterochromatin formation influence only the timing of ORI activation.

Animals↗
PubMed2004

Cannabinoids and gene expression during brain development.

Cannabis is the most commonly used illicit drug in western societies, in particular among young people. It is consumed even by women during pregnancy and lactation, which result in a variety of disturbances in the development of their offspring, because, like other habit-forming drugs, cannabinoids, the psychoactive ingredients of marijuana, can cross the placental barrier and be secreted in the maternal milk. Through this way, cannabinoids affect the ontogeny of various neurotransmitter systems leading to changes in different behavioral patterns. Dopamine and endogenous opioids are among the neurotransmitters that result more affected by perinatal cannabinoid exposure, which, when animals mature, produce changes in motor activity, drug-seeking behavior, nociception and other processes. These disturbances are likely originated by the capability of cannabinoids to influence the expression of key genes for both neurotransmitters, in particular, the enzyme tyrosine hydroxylase and the opioid precursor proenkephalin. In addition, cannabinoids seem to be also able to influence the expression of genes encoding for neuron-glia cell adhesion molecules, which supports a potential influence of cannabinoids on the processes of cell proliferation, neuronal migration or axonal elongation in which these proteins are involved. In support of this possibility, CB1 receptors, which represent the major targets for the action of cannabinoids, are abundantly expressed in certain brain regions, such as the subventricular areas, which have been involved in these processes during brain development. Finally, cannabinoids might also be involved in the apoptotic death that occurs during brain development, possibly by influencing the expression of Bcl-2/Bax system. Also in support of this option, CB1 receptors are transiently expressed during brain development in different group of neurons which do not contain these receptors in the adult brain. This paper will review all evidence relating cannabinoids to the expression of key genes for neural development, trying to establish the future research addressed to elucidate the mechanisms involved in the epigenetic action of cannabinoids during brain development.

Brain↗
PubMed2004

[Surveillance of antimicrobial resistance: VIRA study 2004].

INTRODUCTION: The objective of the study was to know the current situation of the antimicrobial sensitivity patterns of the main multi-resistant bacteria and to analyze any possible changes with respect to the VIRA study carried out in 2001. METHODS: The 40 participating hospitals sent a total of 1,425 microorganisms isolated in February 2004, distributed as follows: penicillin-resistant Streptococcus pneumoniae (139), methicillin-resistant Staphylococcus aureus (289), clinically significant coagulase-negative staphylococci (158), ampicillin-resistant Enterococcus faecium (89) and Enterococcus faecalis (2), ampicillin-resistant Haemophilus influenzae (85), ciprofloxacin-resistant Escherichia coli (346), Pseudomonas aeruginosa (187), and Acinetobacter baumannii (130). The hospitals provided epidemiological data on these microorganisms. Sensitivity was determined by the broth microdilution method. RESULTS: The number of highly penicillin-resistant pneumococci fell significantly (p < 0.0001) compared with the previous study (from 59.8% to 30.2%). Global methicillin-resistance in S. aureus was 31.2%, which represents a significant increase (p < 0.001) compared with the year 2001 (24.8%). 11.3% of the E. coli strains were extended-spectrum beta -lactamase-producers and came from 24 hospitals. One P. aeruginosa isolate gave a positive result in the E-test MBL assay, suggesting the presence of metallo-beta -lactamases. The strains of imipenem-resistant A. baumannii presented cross-resistance with several antibiotics. CONCLUSION: These results show how the multi-resistant bacteria included in the study represent a growing problem in our hospitals. This emphasizes the importance of resistance surveillance systems and the correct use of antimicrobial agents.

Acinetobacter baumannii↗
PubMed2003

Prenatal cannabinoid and gene expression for neural adhesion molecule L1 in the fetal rat brain.

The consumption by women of cannabis derivatives during pregnancy and/or lactation affects the development of their offspring because like other psychoactive drugs, cannabinoids, the psychoactive ingredients of marijuana, can cross the placental barrier and be secreted into the maternal milk. Through this way, cannabinoids are able to affect the expression of key genes for neural developmental leading to neurotransmitter and behavioral disturbances. In this present study, we wanted to explore the influence of prenatal cannabinoid exposure on the gene expression of a key protein for brain development, the neural adhesion molecule L1, which plays an important role in processes of cell proliferation and migration, neuritic elongation and guidance, and synaptogenesis. To this end, pregnant rats were daily treated with delta9-tetrahydrocannabinol (delta9-THC) since the 5th day of gestation up to the day before birth (GD21), day at which rats were killed and their pups removed for analysis of L1-mRNA levels in different brain structures. Our results confirmed that the levels of L1 transcripts were significantly increased after prenatal delta9-THC exposure in several regions such as the fimbria, stria terminalis, stria medullaris and corpus callosum, which share the properties of being white matter regions and containing, exclusively during development, an abundant population of cannabinoid CB1 receptors, the major targets for the action of plant-derived cannabinoids. L1-mRNA levels were also increased in grey matter structures such as the septum nuclei and the habenula, but remained unchanged in most of the grey matter structures analyzed (cerebral cortex, basolateral amygdaloid nucleus, hippocampus, thalamic and hypothalamic nuclei, basal ganglia and subventricular zones) and also in a few white matter structures (fornix and fasciculus retroflexus). An important aspect of these observations is that the increase in L1-mRNA levels reached statistical significance only in the case of delta9-THC-exposed males but not in the case of delta9-THC-exposed females where only trends or no effects were detected, this supporting previous evidence on a sexual dimorphism, with greater effects in male fetuses, for the action of cannabinoids in the developing brain. In summary, cannabinoids seem to influence the expression of L1 in specific brain structures during the prenatal period, which, considering the role played by this protein in different events related to neural development, might explain the neurotransmitter and behavioral disturbances reported after prenatal consumption of marijuana.

Animals↗
PubMed2002

Increased recombination intermediates and homologous integration hot spots at DNA replication origins.

We have studied the relationship between DNA replication and recombination in Schizosaccharomyces pombe using two-dimensional gel electrophoresis and functional analysis. Our results indicate that the activation of replication origins (ORIs) during the mitotic cell cycle is associated with the generation of joint DNA molecules between sister chromatids. The frequency of integration by homologous recombination was up to 50-fold higher than the genomic average within a narrow window overlapping the ars1 replication initiation site. The S. pombe rad22Delta, rhp51Delta, and rhp54Delta mutants, deficient in mitotic recombination, activate ORIs very inefficiently and accumulate abnormal replication intermediates. These results focus on the general link between replication and recombination previously found in several systems and suggest a role for recombination in the initiation of eukaryotic DNA replication.

DNA Replication↗
PubMed2002

Changes in prodynorphin and POMC gene expression in several brain regions of rat fetuses prenatally exposed to Delta(9)-tetrahydrocannabinol.

Recently, we demonstrated that prenatal Delta(9)-tetrahydrocannabinol (Delta(9)-THC) exposure alters proenkephalin mRNA levels in several brain regions of rat fetuses. In the present study, we analyzed mRNA levels of the two other opioid peptide precursors, prodynorphin and pro-opiomelanocortin (POMC), in several brain nuclei of rat fetuses which were exposed daily to Delta(9)-THC from day 5 of gestation. Prenatal Delta(9)-THC exposure altered POMC and prodynorphin mRNA levels in most of the brain areas studied at different fetal ages, but the effects were sex-dependent. Thus, POMC mRNA levels increased in Delta(9)-THC-exposed females, but decreased in Delta(9)-THC-exposed males at GD21 in the arcuate nucleus, cerebral cortex and habenular nuclei. POMC mRNA levels also increased in the arcuate nucleus and cerebral cortex of Delta(9)-THC-exposed fetuses at GD18. Prodynorphin mRNA levels were not altered by the prenatal Delta(9)-THC exposure in the striatum, cerebral cortex, hippocampus and hypothalamic structures of fetuses at GD16 and GD18, but a sexually dimorphic response was observed at GD21. Thus, prodynorphin mRNA levels increased in the cerebral cortex, hippocampus and paraventricular hypothalamic nucleus of Delta(9)-THC-exposed females, whereas no changes were observed in Delta(9)-THC-exposed males. In summary, Delta(9)-THC exposure altered the prenatal development of POMC and prodynorphin mRNA levels in several brain structures. Changes in POMC were similar to those reported previously for proenkephalin, increases in females but decreases in males, whereas changes in prodynorphin were only observed in females.

Journal Article↗
PubMed2002

In vitro activities of tigecycline (GAR-936) against recently isolated clinical bacteria in Spain.

The antimicrobial activities of tigecycline (GAR-936) were compared with those of other agents against 1,087 strains recently isolated in 12 Spanish medical centers. Tigecycline showed activity against a wide spectrum of aerobic and anaerobic bacteria, including strains such as methicillin-resistant Staphylococcus aureus, coagulase-negative staphylococci, penicillin-resistant Streptococcus pneumoniae, Enterococcus faecium, Acinetobacter baumannii, and Stenotrophomonas maltophilia.

Anti-Bacterial Agents↗
PubMedDate not supplied

Clinical findings as predictors of positivity of head-up tilt table test in neurocardiogenic syncope.

BACKGROUND: Neurocardiogenic (vasovagal) syncope occurs frequently and can be diagnosed with the head-up tilt table (HUTT) test. Our objective in this study was to identify clinical predictors of the positivity of HUTT test in neurocardiogenic syncope. METHODS: We conducted a prospective study of 117 cases (81 women and 36 men, 13-85 years of age) referred to our Institution for HUTT testing. The ability of 10 symptoms and signs of clinical history to predict HUTT positivity were evaluated using logistic regression analysis. RESULTS: We observed a low rate of test-negative cases (24%) and 89 positives. Nearly all positives (87/89) were neurocardiogenic, principally of vasodepressor and mixed types (43 and 34 cases, respectively) and a few were cardioinhibitory (10, mostly young males). Regression analysis established that dizziness, nausea, and diaphoresis in past history were associated with HUTT positivity nearly 25 times more frequently than when absent. CONCLUSIONS: Our three conclusions are that syncope in absence of heart disease accompanied by dizziness, nausea, and diaphoresis may be treated as neurocardiogenic in settings where no HUTT is available. In addition, our low rate of negative tests may have been the result of our reexamining referrals prior to deciding test performance, and high frequency of young males in cardioinhibitory syncope needs further research.

Adolescent↗
PubMedDate not supplied

Loss of cannabinoid CB(1) receptors in the basal ganglia in the late akinetic phase of rats with experimental Huntington's disease.

We have recently examined the status of the endocannabinoid transmission in the basal ganglia in Huntington's disease (HD) using a rat model generated by bilateral intrastriatal injections of 3-nitropropionic acid (3-NP). In these previous studies, we focused on the early phase of hyperactivity that occurs 1-2 weeks after the lesion, comparable to early grades of the human disease, while in the present study, we wanted to explore the late akinetic phase observed 3-4 weeks after the lesion (similar to advanced grades). First, we confirmed that 3-NP-lesioned rats exhibited a marked akinesia tested at 4 weeks post-lesion. We observed a marked reduction in ambulatory and exploratory activities and a trend towards a decrease in stereotypies, paralleled by a strong increase in the time spent in inactivity. There was also a profound reduction in GABA contents and glutamic acid decarboxylase activity, particularly in the caudate-putamen and the globus pallidus. Dopamine and DOPAC contents, as well as the activity of tyrosine hydroxylase, were also reduced, particularly in the caudate-putamen. mRNA levels for neuronal-specific enolase, proenkephalin and substance P were also dramatically reduced in the caudate-putamen, thus indicating a death of both the direct (striatonigral) and the indirect (striatopallidal) GABAergic projection pathways, which corresponded with a marked loss of CB(1) receptor-mRNA levels observed in both parts, lateral and medial, of the caudate-putamen. However, losses of CB(1) receptor binding were confined to the globus pallidus and the caudate-putamen, whereas there were no changes in the substantia nigra and the entopeduncular nucleus. Finally, we failed to reduce the marked akinesia found in these animals by administering SR141716A, a selective antagonist of CB(1) receptors, which had exhibited hyperlocomotor effects in previous studies with naive animals. In summary, behavioral and biochemical changes observed in rats intrastriatally lesioned with 3- NP were compatible with a profound degeneration of striatal efferent GABAergic neurons, similar to those occurring in advances stages of the human disease. As expected, a loss of CB(1) receptors was evident in the basal ganglia of these rats during the late akinetic stage of the disease. Further studies should demonstrate whether these receptors might be a target for a new therapy in HD, a disease with a poor pharmacological outcome.

Journal Article↗
PubMedDate not supplied

[Description of the resting electrocardiogram in a series of patients with myasthenia gravis].

UNLABELLED: Myasthenia gravis (MG) is a disease characterized by the presence of acetylcholine receptor-directed autoantibodies. Functional cardiac disorders are the most common since there is no neuro-muscular plate in the heart. Autonomic nervous system is involved in MG, but the cardiac manifestations of such an involvement remain unclear. Previous EKG studies in patients with MG show heterogeneous results. MATERIAL AND METHODS: A retrospective, descriptive and observational study was performed to know the main electrocardiographic characteristics and some autonomic nervous function in a series of patients with MG. RESULTS: One-hundred seventeen patients with EKG were analyzed. Twenty-eight were 47.9 +/- 20 years-old males, and 89 were women of 35.2 +/- 7.7 years (p = 0.001). 49 (41.9%) EKG had no changes, while 68 (58.1%) did. The main QT dispersion was 35.5 +/- 18.4 ms among those with some anomaly (p = 0.27). In 54 (78.3%) patients with an abnormal EKG there was T wave alternans, which was also present in 35 (71.4%) (p = 0.32) patients with normal EKG. CONCLUSIONS: MG is frequently associated to unspecific EKG changes. Dynamic electrocardiography allows a precise evaluation of the kind of cardiac involvement derived from MG, specifically the one related to the autonomic function, that is apparently affected in both the sympathetic and parasympathetic arms.

Adult↗