Biomedical subjects

Carlos Romero

Publications and source records attributed to Carlos Romero.

At least 19 recordsLinked to original sources

PubMed2006

TNFalpha release from peripheral blood leukocytes depends on a CRM1-mediated nuclear export.

Tumor necrosis factor-alpha (TNFalpha) is a potent pro-inflammatory cytokine that plays a major role in the pathogenesis of acute and chronic inflammatory disorders such as septic shock and arthritis, respectively. Leukocytes stimulated with inflammatory signals such as lipopolysaccharide (LPS) are the predominant producers of TNFalpha, and thus control of TNFalpha release from stimulated leukocytes represents a potential therapeutic target. Here, we report that leptomycin B (LMB), a specific inhibitor of CRM1-dependent nuclear protein export, inhibits TNFalpha release from LPS-stimulated human peripheral blood neutrophils and mononuclear cells. In addition, immunofluorescence confocal microscopy and immunoblotting analysis indicate that TNFalpha is localized in the nucleus of human neutrophils and mononuclear cells. This study demonstrates that the cellular release of TNFalpha from stimulated leukocytes is mediated by the CRM1-dependent nuclear export mechanism. Inhibition of CRM1-dependent cellular release of TNFalpha could thus provide a novel therapeutic approach for disorders involving excessive TNFalpha release.

Active Transport, Cell Nucleus↗

PubMed2006

Self-compatibility of two apricot selections is associated with two pollen-part mutations of different nature.

Loss of pollen-S function in Prunus self-compatible mutants has recently been associated with deletions or insertions in S-haplotype-specific F-box (SFB) genes. We have studied two self-compatible cultivars of apricot (Prunus armeniaca), Currot (S(C)S(C)) and Canino (S(2)S(C)), sharing the naturally occurring self-compatible (S(C))-haplotype. Sequence analysis showed that whereas the S(C)-RNase is unaltered, a 358-bp insertion is found in the SFB(C) gene, resulting in the expression of a truncated protein. The alteration of this gene is associated with self-incompatibility (SI) breakdown, supporting previous evidence that points to SFB being the pollen-S gene of the Prunus SI S-locus. On the other hand, PCR analysis of progenies derived from Canino showed that pollen grains carrying the S(2)-haplotype were also able to overcome the incompatibility barrier. However, alterations in the SFB(2) gene or evidence of pollen-S duplications were not detected. A new class of F-box genes encoding a previously uncharacterized protein with high sequence similarity (approximately 62%) to Prunus SFB proteins was identified in this work, but the available data rules them out of producing S-heteroallelic pollen and thus the cause of the pollen-part mutation. These results suggest that cv Canino has an additional mutation, not linked to the S-locus, which causes a loss of pollen-S activity when present in pollen. As a whole, these findings support the proposal that the S-locus products besides other S-locus independent factors are required for gametophytic SI in Prunus.

Alleles↗

PubMed2006

High-volume hemofiltration as salvage therapy in severe hyperdynamic septic shock.

OBJECTIVES: To evaluate the effect of short-term (12-h) high-volume hemofiltration (HVHF) in reversing progressive refractory hypotension and hypoperfusion in patients with severe hyperdynamic septic shock. To evaluate feasibility and tolerance and to compare observed vs. expected hospital mortality. DESIGN AND SETTING: Prospective, interventional, nonrandomized study in the surgical-medical intensive care unit of an academic tertiary center. PATIENTS: Twenty patients with severe septic shock, previously unresponsive to a multi-intervention approach within a goal-directed, norepinephrine-based algorithm, with increasing norepinephrine (NE) requirements (>0.3 microg kg(-1) min(-1)) and lactic acidosis. INTERVENTIONS: Single session of 12-h HVHF. MEASUREMENTS AND RESULTS: We measured changes in NE requirements and perfusion parameters every 4h during HVHF and 6h thereafter. Eleven patients showed decreased NE requirements and lactate levels (responders). Nine patients did not fulfill these criteria (nonresponders). The NE dose, lactate levels, and heart rates decreased and arterial pH increased significantly in responders. Hospital mortality (40%) was significantly lower than predicted (60%): 67% (6/9) in nonresponders vs. 18% (2/11) in responders. Of 12 survivors 7 required only a single 12-h HVHF session. On logistic regression analysis the only statistically significant predictor of survival was theresponse to HVHF (odds ratio 9). CONCLUSIONS: A single session of HVHF as salvage therapy in the setting of a goal-directed hemodynamic management algorithm may be beneficial in severe refractory hyperdynamic septic-shock patients. This approach may improve hemodynamics and perfusion parameters, acid-base status, and ultimately hospital survival. Moreover, it is feasible, and safe.

Adult↗

PubMed2006

Implementation of a norepinephrine-based protocol for management of septic shock: a pilot feasibility study.

BACKGROUND: The subject of the best vasopressor for hemodynamic management of septic shock (SS) is controversial. One of the difficulties in planning such studies is that physicians are reluctant to use one vasopressor exclusively, and there is considerable variation in practice. The aim of this study was to test the feasibility of implementing a single pressor-based algorithm (in this case, norepinephrine [NE]). METHODS: A NE-based algorithm was applied prospectively to 100 consecutive SS patients. A formal training program was implemented before starting the protocol and applied to 72 physicians and nurses involved in intensive care unit (ICU) patient care. Compliance, protocol violations, probable adverse effects, and outcome were evaluated on a daily basis by an independent group of fellows and a research nurse. RESULTS: In 100 patients, there were 7,139 hours of algorithm use. Only 13 protocol violations were observed, mostly in the timing of inotropic drugs. Senior staff physicians or busy night shifts accounted for most of these violations. ICU mortality was 33%, which is comparable to that predicted by Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores. Adverse events probably related to NE were not observed. CONCLUSIONS: The present algorithm, applied after a strict training program, obtained an overall good acceptance and compliance with very few protocol violations in more than 7,000 hours of use. Safety was demonstrated by a global mortality comparable to that predicted by severity scores and absence of specific drug-related morbidity. The implementation of a single pressor-based algorithm for SS is feasible and safe.

Adult↗

PubMed2006

Deiodinase type 1 activity is expressed in the prostate of pubescent rats and is modulated by thyroid hormones, prolactin and sex hormones.

The aim of this study was to characterize the type of 5'-deiodinase activity in the prostate of pubescent rats (7-8 weeks), to establish its distribution in the lobes (ventral, dorsolateral, and anterior), and to analyze its modulation by prolactin (PRL), testosterone, dihydrotestosterone (DHT), and 17beta-estradiol (E(2)). Our results showed that the enzymatic activity was highly susceptible to inhibition by 6-n-propyl-2-thiouracil and gold thioglucose, its preferential substrate was reverse tri-iodothyronine (rT(3)), it exhibited a low dithiothreitol requirement (5 mM), and the apparent K(m) and V(max) values for substrate (rT(3)) were approximately 0.25 microM and 9.0 pmol liberated/mg protein per hour, respectively. All these characteristics indicate the preferential expression of type 1 deiodinase (D1), which was corroborated by demonstrating the presence of D1 mRNA in prostate. D1 activity was detected in all lobes and was most abundant in the dorsolateral. Although we detected type 2 deiodinase (D2) mRNA expression, the D2 activity was almost undetectable. D1 activity was enhanced in animals with hyperthyroidism and hyperprolactinemia, in intact animals treated with finasteride (inhibitor of local DHT production), and in castrated animals with E(2) replacement. In contrast, activity diminished in castrated animals with testosterone replacement. Our results suggest that thyroid hormones, PRL, and E(2) exert a positive modulation on D1 activity, while testosterone and DHT exhibit an inhibitory effect. D1 activity may be associated with prostate maturation and/or function.

Animals↗

PubMed2005

Expression of FLR1 transporter requires phospholipase C and is repressed by Mediator.

In budding yeast, phosphoinositide-specific phospholipase C (Plc1p encoded by PLC1 gene) is important for function of kinetochores. Deletion of PLC1 results in benomyl sensitivity, alterations in chromatin structure of centromeres, mitotic delay, and a higher frequency of chromosome loss. Here we intended to utilize benomyl sensitivity as a phenotype that would allow us to identify genes that are important for kinetochore function and are downstream of Plc1p. However, our screen identified SIN4, encoding a component of the Mediator complex of RNA polymerase II. Deletion of SIN4 gene (sin4Delta) does not suppress benomyl sensitivity of plc1Delta cells by improving the function of kinetochores. Instead, benomyl sensitivity of plc1Delta cells is caused by a defect in expression of FLR1, and the suppression of benomyl sensitivity in plc1Delta sin4Delta cells occurs by derepression of FLR1 transcription. FLR1 encodes a plasma membrane transporter that mediates resistance to benomyl. Several other mutations in the Mediator complex also result in significant derepression of FLR1 and greatly increased resistance to benomyl. Thus, benomyl sensitivity is not a phenotype exclusively associated with mitotic spindle defect. These results demonstrate that in addition to promoter-specific transcription factors that are components of the pleiotropic drug resistance network, expression of the membrane transporters can be regulated by Plc1p, a component of a signal transduction pathway, and by Mediator, a general transcription factor. The results thus suggest another layer of complexity in regulation of pleiotropic drug resistance.

Benomyl↗

PubMed2005

Red wine reduces oxidative stress in patients with acute coronary syndrome.

BACKGROUND: Moderate red wine consumption improved endothelial function in normal volunteers. Herein we explored the effects of moderate red wine consumption in endothelial function and in oxidative stress in patients with an acute coronary syndrome. METHODS: 20 patients treated with percutaneous coronary interventions after an acute coronary syndrome were randomized to a red-wine group (n=9, 250 ml daily, Cabernet Sauvignon) or to a control group (n=11, abstinence from alcoholic beverages). Studies were performed at baseline and after 2 months. Endothelial function was estimated by flow-mediated vasodilatation of the brachial artery. Plasma antioxidant capacity was measured by total antioxidant reactivity and ferric reducing antioxidant power. Oxidative damage was evaluated by measurements of 8-OH deoxyguanosine content in leukocyte deoxyribonucleic acid. RESULTS: The endothelium dependent/independent dilatation ratio significantly improved compared to baseline in both groups. The 8-OH deoxyguanosine content decreased significantly in both groups; this effect was more pronounced with wine (p<0.002 vs. control). Oxidative deoxyribonucleic acid damage in controls decreased from 13.1+/-1.1 to 10.0+/-1.0 (p<0.003); with wine from 13+/-0.8 to 5.6+/-0.7 per 10(5) guanosines (p<0.001; p<0.002 vs. control). Total antioxidant reactivity increased from 240+/-18 to 268+/-18 microM in the control group and from 273+/-20 to 330+/-15 microM in the wine group (p<0.03 vs. control). Ferric reducing antioxidant power increased from 1106+/-60 to 1235+/-42 microM in the control group and from 1219+/-82 to 1450+/-63 microM in the wine group (p<0.001 vs. control). CONCLUSIONS: The addition of moderate amounts of red wine did not improve endothelial function beyond conventional therapy, whereas it showed benefits in parameters of oxidative stress in these patients.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2005

Interaction of Pik1p and Sjl proteins in membrane trafficking.

Phosphatidylinositol (PtdIns) phosphates are involved in signal transduction, cytoskeletal organization, and membrane traffic. PtdIns 4-phosphate [PtdIns(4)P], produced in yeast by PtdIns 4-kinase (Pik1p), appears to regulate Golgi secretory function. PtdIns(4)P is also produced by dephosphorylation of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2], catalyzed by one of the three yeast Sjl proteins, homologs of the mammalian synaptic vesicle-associated PtdIns(4,5)P2 5-phosphatase, synaptojanin. To determine whether Pik1p and Sjl proteins operate in the same pathway or regulate the same process, we used a genetic approach. Mutation in the PIK1 gene displays synthetic genetic interactions with deletions of individual SJL genes. Deletion of SJL3 gene is synthetically lethal with pik1ts, and deletions of SJL1 or SJL2 genes in pik1ts cells exacerbate the temperature sensitivity, neomycin sensitivity, and defect in invertase secretion. A diminished level of PtdIns(4)P and increased level of PtdIns(4,5)P2 in pik1(ts)sjl1delta and pik1(ts)sjl2delta cells, compared with pik1ts cells, indicate that PtdIns(4)P is specifically required for secretion. Collectively, our results suggest that Pik1p and the Sjl proteins coordinately function to regulate the dynamic phosphorylation-dephosphorylation of the polar heads of phosphoinositides, and this process appears to be important for membrane trafficking pathways.

1-Phosphatidylinositol 4-Kinase↗

PubMed2005

Management of septic shock with a norepinephrine-based haemodynamic algorithm.

UNLABELLED: Management of septic shock (SS) with a norepinephrine (noradrenaline)-based haemodynamic algorithm. INTRODUCTION: The choice of the best vasopressor for haemodynamic management of septic shock is controversial. Nevertheless, very few studies have been focused on evaluating different management algorithms. The aim of this study was to evaluate the performance of a norepinephrine (NE)-based management protocol. Experience with NE as the initial vasopressor, even if not comparative, could bring relevant data for planning future trails. We also wanted to evaluate the compliance of critical care physicians and nurses with haemodynamic management protocol. PATIENTS AND METHOD: A norepinephrine-based algorithm for the management of septic shock that commands different sequential interventions according to its requirements, was applied prospectively to 100 consecutive septic shock patients. RESULTS: Norepinephrine was used as the first vasoactive drug in all patients with a maximum dose of 0.31+/-0.3 microg kg(-1)min(-1) and an ICU mortality of 33%. Physicians applied correctly all the steps of the algorithm in 92% of the patients. Applying the algorithm, avoided the use of pulmonary artery catheter in 31 patients and led to use of lower doses of vasoactive agents than in many other clinical experiences. CONCLUSION: In conclusion, our data support extended use of an algorithm based on norepinephrine for treating septic shock patients. This is the first clinical study that uses NE as the initial vasopressor drug systematically, and although not comparative, the mortality rates adjusted to APACHE II, are comparable to other studies. It also gives support for future clinical trials comparing norepinephrine with dopamine in this setting.

Aged↗

PubMed2005

Ellagic acid potentiates the effect of quercetin on p21waf1/cip1, p53, and MAP-kinases without affecting intracellular generation of reactive oxygen species in vitro.

Anticarcinogenic effects attributed to polyphenols in fruits may be based on synergistic, additive, or antagonistic interactions of many compounds. In a previous study, it was demonstrated that quercetin and ellagic acid interacted synergistically in the induction of apoptosis in the human leukemia cell line, MOLT-4. To investigate possible cellular mechanisms, this study evaluated whether synergistic effects might be detectable within proapoptotic or antiproliferative signal transduction pathways. We found that quercetin and combinations of quercetin and ellagic acid nonsynergistically increased p53 protein levels. In contrast, ellagic acid potentiated the effects of quercetin for p21(cip1/waf1) protein levels and p53 phosphorylation at serine 15, possibly explaining the synergistic effect observed in apoptosis induction. Phosphorylation of the mitogen-activated protein (MAP) kinases, c-jun N-terminal (JNK)1,2 and p38, was also increased by the combination of ellagic acid and quercetin, whereas quercetin alone induced only p38. We further evaluated whether the generation of reactive oxygen species (ROS) and/or quercetin stability were influenced by interactions of ellagic acid with quercetin. Quercetin increased the generation of ROS, which was neither potentiated nor inhibited by ellagic acid. The stability of intracellular and extracellular quercetin was not influenced by the presence of ellagic acid. In summary, quercetin and ellagic acid combined increase the activation of p53 and p21(cip1/waf1) and the MAP kinases, JNK1,2 and p38, in a more than additive manner, suggesting a mechanism by which quercetin and ellagic acid synergistically induce apoptosis in cancer cells.

Cell Cycle Proteins↗

PubMed2005

Genetic diversity of loquat germplasm (Eriobotrya japonica (Thunb) Lindl) assessed by SSR markers.

Genetic relationships among 40 loquat (Eriobotrya japonica (Thunb) Lindl) accessions that originated from different countries and that are part of the germplasm collection of the Instituto Valenciano de Investigaciones Agrarias (IVIA) (Valencia, Spain) were evaluated using microsatellites. Thirty primer pairs flanking microsatellites previously identified in Malus x domestica (Borkh.) were assayed. Thirteen of them amplified polymorphic products and unambiguously distinguished 34 genotypes from the 40 accessions analyzed. Six accessions showing identical marker patterns were Spanish local varieties thought to have been derived from 'Algerie' by a mutational process very common in loquat species. A total of 39 alleles were detected in the population studied, with a mean value of 2.4 alleles per locus. The expected and observed heterozygosities were 0.46 and 51% on average, respectively, leading to a negative value of the Wright's fixation index (-0.20). The values of these parameters indicate a smaller degree of genetic diversity in the set of loquat accessions analyzed than in other members of the Rosaceae family. Unweighted pair-group method (UPGMA) cluster analysis, based on Nei's genetic distance, generally grouped genotypes according to their geographic origins and pedigrees. The high number of alleles and the high expected heterozygosity detected with SSR markers developed in Malus x domestica (Borkh.) make them a suitable tool for loquat cultivar identification, confirming microsatellite marker transportability among genera in the Rosaceae family.

Eriobotrya↗

PubMed2004

The trehalose pathway and intracellular glucose phosphates as modulators of potassium transport and general cation homeostasis in yeast.

Trk, encoded by the partially redundant genes TRK1 and TRK2, is the major potassium transporter of Saccharomyces cerevisiae. This system is specific for potassium and rubidium but, by reducing the electrical membrane potential of the plasma membrane, Trk decreases the uptake of toxic cations such as lithium, calcium, aminoglycosides and polyamines, which are transported by other systems. Gain- and loss-of-function studies indicate that TPS1, a gene encoding trehalose-6-phosphate synthase and known to modulate glucose metabolism, activates Trk and reduces the sensitivity of yeast cells to many toxic cations. This effect is independent of known regulators of Trk, such as the Hal4 and Hal5 protein kinases and the protein phosphatase calcineurin. Mutants defective in isoform 2 of phosphoglucomutase (pgm2) and mutants defective in isoform 2 of hexokinase (hxk2) exhibit similar phenotypes of reduced Trk activity and increased sensitivity to toxic cations compared with tps1 mutants. In all cases Trk activity was positively correlated with levels of glucose phosphates (glc-1-P and glc-6-P). These results indicate that Tps1, like Pgm2 and Hxk2, increases the levels of glucose phosphates and suggest that these metabolites, directly or indirectly, activate Trk.

Adenosine Triphosphatases↗

PubMed2004

Sustainability of forest management plans: a discrete goal programming approach.

Let us consider i = 1, 2,...n alternative forest plans to be evaluated according to j = 1, 2,...m indicators of sustainability. An expert or panel of experts suggests a set of targets or desirable levels of achievement for the m indicators of sustainability considered. Within this context, an important problem is to determine the system with a higher level of achievement with respect to the targets attached by the expert to the m indicators. A natural extension of this problem involves determining a ranking of the n systems considered. A general procedure based on discrete goal programming is proposed to address these problems. The methodology is applied in a case study of a Spanish forest.

Conservation of Natural Resources↗

PubMed2004

[Mechanical ventilation in patients with acute neurological disease: survival and functional outcome].

BACKGROUND: The need of mechanical ventilation among patients with acute neurological diseases is considered a poor prognostic sign. AIM: To determine the mortality and functional recovery of neurological patients requiring mechanical ventilation. PATIENTS AND METHODS: Prospective study of 77 patients (42 men, age 54+/-19 years, with 11+/-4 points of Glasgow coma scale (GCS), 61% with cerebrovascular disease), that were admitted to the intensive care unit with neurological disease and that required mechanical ventilation. Functional recovery was assessed at 18 months with Glasgow outcome scale (GOS) and Barthel index. RESULTS: Thirty percent of patients died during follow up. Among surviving patients, 47% had a good recovery or moderate disability, and 74% had a Barthel index equal to or over 70. Arterial hypertension, age over 70 and mechanical ventilation longer than 6 days were associated with bad functional prognosis. CONCLUSIONS: Neurological patients requiring mechanical ventilation had a lower mortality than previously reported, and half of the survivors have an independent life. This study supports intensive care management in this group of patients.

Acute Disease↗

PubMed2003

A novel porcine gammaherpesvirus.

A novel porcine gammaherpesvirus was detected in the blood of domestic pigs by PCR. With degenerate-primer PCR and subsequent long-distance PCR approaches a 60-kbp genome stretch was amplified. Sequence analysis revealed the presence of the gammaherpesvirus ORFs 03 to 46 as well as a putative chemokine receptor and a v-bcl-2 gene. The 60-kbp sequence was compared with the corresponding sequence of the porcine lymphotropic herpesvirus 1 (PLHV-1) published recently and the sequence of PLHV-2, which was amplified from porcine tonsil. Considerable sequence differences (amino acid identities: 49-89%) were found between the novel virus and PLHV-1 as well as PLHV-2, which were very closely related to each other (amino acid identities: 85-98%). The novel virus had essentially the same genome organization as PLHV-1 and -2 and was therefore designated PLHV-3. Like PLHV-1 and -2, PLHV-3 was frequently found in the blood and in lymphoid organs of domestic and feral pigs from different geographic locations. In the blood, the PLHVs were detected predominantly in B-cells. Indication for latent as well as productive PLHV-3 infection was found in the porcine B-cell line L23. It can be concluded that the PLHVs are widespread and are likely to cause a persistent B-lymphotropic infection. Since PLHV-1 has been implicated in the development of porcine posttransplantation lymphoproliferative disease, all porcine lymphotropic gammaherpesviruses are of concern when pigs are used as donors in xenotransplantation.

Animals↗

PubMed2003

Lithium treatment induces a hypersensitive-like response in tobacco.

Treatment of tobacco ( Nicotiana tabacum L.) plants with lithium induces the formation of necrotic lesions and leaf curling as in the case of incompatible pathogen interactions. Further similarities at the molecular level include accumulation of ethylene and of salicylic and gentisic acids, and induced expression of pathogenesis-related PR-P, PR5 and PR1 genes. With the exception of PR1 induction, lithium produced the same effects in transgenic tobacco plants that do not accumulate salicylate because of overexpression of the bacterial hydroxylase gene nahG. On the other hand, inhibition of ethylene biosynthesis with aminoethoxyvinylglycine prevented lithium-induced cell death and PR5 expression. These results suggest that lithium triggers a hypersensitive-like response where ethylene signalling is essential.

Apoptosis↗

PubMed2003

Genetic diversity of different apricot geographical groups determined by SSR markers.

Forty apricot cultivars with different geographic origins belonging to the germplasm collections of St. Istvan University (Budapest, Hungary) and the Instituto Valenciano de Investigaciones Agrarias (IVIA) (Valencia, Spain) were studied by means of SSR markers. The aim of the study was to determine the genetic relationships among genotypes from different eco-geographical groups. Sixteen primer pairs flanking microsatellite sequences in the peach genome were assayed. Eleven of them were polymorphic in the set of cultivars studied and allowed every genotype to be unambiguously distinguished. Genetic diversity in the population studied was analyzed using several variability parameters. A total of 34 alleles were detected with a mean value of 3.1 alleles/locus. The expected heterozygosity mean was 0.46 and the observed heterozygosity was 32% on an average leading to a high value of the Wright's fixation index (0.32). Additionally, UPGMA cluster analysis based on Nei's genetic distance grouped genotypes according to their geographic origins and pedigrees. SSR markers have proved to be an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in apricot.

Alleles↗

PubMed2003

[Hantavirus cardiopulmonary syndrome: utility of the PICCO(Pulse contour cardiac output) system for monitoring].

We report a 68 years old man, farmer from the metropolitan region, admitted with a Hantavirus Cardiopulmonary Syndrome. The diagnosis was made using serologic test and was later confirmed by the Public Health Institute. He evolved to an early multiple organ failure, requiring high concentrations of oxygen and invasive ventilatory assistance, vasopressor drugs and renal replacement therapy. Swan Ganz and PiCCO were used simultaneously for hemodynamic monitoring. Treatment consisted in global support therapy, antimicrobial therapy and systemic corticosteroids. Intrathoracic blood volume was a more reliable parameter than pulmonary capillary wedge pressure for the assessment of preload. As expected in situations of increased vascular permeability, there was an increase in extravascular lung water. There was a good correlation between extravascular lung water and oxygenation parameters (PaO2/FiO2 and oxygenation index). PiCCO system may become a helpful tool in the management of patients with Hantavirus Cardiopulmonary Syndrome.

Aged↗