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Biomedical subjects

E Moreno

Publications and source records attributed to E Moreno.

At least 73 records · Page 4Linked to original sources
PubMed2000

Effect of verapamil on home self-measurement of blood pressure and heart rate by hypertensive patients. Verapamil-Frequency Research Group.

BACKGROUND: Achievement of a controlled blood pressure and improvement of cardiovascular risk profile are the mainstays of therapy for hypertension. OBJECTIVE: To assess the responses of heart rate and blood pressure in hypertensive patients to 240 mg/day sustained release verapamil. METHODS: We assessed the effect of 240 mg/day sustained released verapamil on blood pressure and heart rate, measured in the office and at home, in 1395 hypertensive outpatients with mild-to-moderate hypertension, who were using an Omron HEM 705 CP automatic device for self-measurement. The period of observation was 3 months. RESULTS: Blood pressure decreased both in the medical office and at the patient's home, the measurements obtained at home being lower than those found in the office. Heart rate decreased in a significant and particular way. The decrease was greatest among those patients with histories of myocardial infarction and among relatively young patients, who exhibit a tendency towards higher than normal baseline heart rates. Overall, there was a shift of the heart-rate curve towards more controlled levels clustered around heart rates between 65 and 75 beats/min. Home self-measurement showed that the data gathered by the patients at home are reliable and that, when cut-off values of 140/90 mm Hg for blood pressure are used, the percentage of patients with controlled blood pressures is 62%, whereas the percentage obtained in the medical office by the physician is 56%. If cut-off values of 135/85 mm Hg are considered for self-measurements at home, according to the VI JNC recommendations, the percentage of patients with controlled blood pressures is 25.4%.

Adult↗
PubMed2000

Internal trehalose protects endocytosis from inhibition by ethanol in Saccharomyces cerevisiae.

Endocytosis in Saccharomyces cerevisiae is inhibited by concentrations of ethanol of 2 to 6% (vol/vol), which are lower than concentrations commonly present in its natural habitats. In spite of this inhibition, endocytosis takes place under enological conditions when high concentrations of ethanol are present. Therefore, it seems that yeast has developed some means to circumvent the inhibition. In this work we have investigated this possibility. We identified two stress conditions under which endocytosis was resistant to inhibition by ethanol: fermentation during nitrogen starvation and growth on nonfermentable substrates. Under these conditions, yeast accumulates stress protectors, primarily trehalose and Hsp104, a protein required for yeast to survive ethanol stress. We found the following. (i) The appearance of ethanol resistance was accompanied by trehalose accumulation. (ii) Mutant cells unable to synthesize trehalose also were unable to develop resistance. (iii) Mutant cells that accumulated trehalose during growth on sugars were resistant to ethanol even under this nonstressing condition. (iv) Mutant cells unable to synthesize Hsp104 were able to develop resistance. We conclude that trehalose is the major factor in the protection of endocytosis from ethanol. Our results suggest another important physiological role for trehalose in yeast.

Endocytosis↗
PubMed2000

Brucella abortus and its closest phylogenetic relative, Ochrobactrum spp., differ in outer membrane permeability and cationic peptide resistance.

The outer membrane (OM) of the intracellular parasite Brucella abortus is permeable to hydrophobic probes and resistant to destabilization by polycationic peptides and EDTA. The significance of these unusual properties was investigated in a comparative study with the opportunistic pathogens of the genus Ochrobactrum, the closest known Brucella relative. Ochrobactrum spp. OMs were impermeable to hydrophobic probes and sensitive to polymyxin B but resistant to EDTA. These properties were traced to lipopolysaccharide (LPS) because (i) insertion of B. abortus LPS, but not of Escherichia coli LPS, into Ochrobactrum OM increased its permeability; (ii) permeability and polymyxin B binding measured with LPS aggregates paralleled the results with live bacteria; and (iii) the predicted intermediate results were obtained with B. abortus-Ochrobactrum anthropi and E. coli-O. anthropi LPS hybrid aggregates. Although Ochrobactrum was sensitive to polymyxin, self-promoted uptake and bacterial lysis occurred without OM morphological changes, suggesting an unusual OM structural rigidity. Ochrobactrum and B. abortus LPSs showed no differences in phosphate, qualitative fatty acid composition, or acyl chain fluidity. However, Ochrobactrum LPS, but not B. abortus LPS, contained galacturonic acid. B. abortus and Ochrobactrum smooth LPS aggregates had similar size and zeta potential (-12 to -15 mV). Upon saturation with polymyxin, zeta potential became positive (1 mV) for Ochrobactrum smooth LPS while remaining negative (-5 mV) for B. abortus smooth LPS, suggesting hindered access to inner targets. These results show that although Ochrobactrum and Brucella share a basic OM pattern, subtle modifications in LPS core cause markedly different OM properties, possibly reflecting the adaptive evolution of B. abortus to pathogenicity.

Alphaproteobacteria↗
PubMed2000

[Laparoscopic cholecystectomy without pneumoperitoneum. A review of 150 cases].

One hundred and fifty laparoscopic cholecystectomies without pneumoperitoneum (LCWP) cases were reviewed. Age, sex, duration of surgical procedures, postoperative pain, complications and length of hospital stay data were also analyzed. We concluded that LCWP avoids complication related to its use and has become a sound option particularly for those patients with a history of cardiorespiratory failure where pneumoperitoneum approach is hindered. Hence, laparoscopic cholecystectomy prescription is widened.

Adult↗
PubMed1999

Tyr-->Trp-substituted peptide 115-129 of a Lys49 phospholipase A(2) expresses enhanced membrane-damaging activities and reproduces its in vivo myotoxic effect.

Myotoxin II is a group II Lys49 phospholipase A(2) (PLA(2)) isolated from the venom of the snake Bothrops asper. Previous studies on a synthetic peptide derived from its heparin-binding, cationic/hydrophobic sequence 115-129 demonstrated a direct functional role of this particular region in the in vitro cytolytic and bactericidal actions of the protein. Nevertheless, no significant myonecrosis has been observed after local intramuscular injection of peptide 115-129 (p115-129) in mice. Since the membrane-damaging action of p115-129 was proposed to depend on its amphiphilic character, the present study examined the effects of substituting its cluster of three tyrosine residues by tryptophan residues, on its toxic/pharmacological activities in vitro and in vivo. This substitution resulted in a drastic enhancement of the membrane-damaging activities of the peptide (p115-W3), together with the clear expression of myotoxic activity in vivo. Both the heparin-binding and antigenic characteristics of p115-129 were essentially conserved in p115-W3, suggesting that the modification did not lead to radical structural alterations. In addition to myotoxicity, cytotoxicity, and bactericidal action, p115-W3 exerted edema-forming activity in the mouse footpad assay. Thus, the synthetic 13-mer p115-W3 reproduced all the known toxic effects of myotoxin II. In spite of its potent membrane-damaging actions, p115-W3 did not acquire direct hemolytic activity upon mouse erythrocytes, an effect which is not present in myotoxin II, but that has been ascribed to the presence of tryptophan in other cationic, membrane-damaging peptides such as mellitin from bee venom. The myotoxic activity of p115-W3 herein described constitutes the first example of a short, PLA(2)-based linear synthetic peptide with the ability to reproduce this effect of a parent protein in vivo. This finding is in clear support of the proposed relevance of the C-terminal region 115-129 in all the membrane-damaging mechanisms exerted by myotoxin II, including the myotoxic mechanism.

Amino Acid Sequence↗
PubMed1999

Caudal is the Hox gene that specifies the most posterior Drosophile segment.

The homeobox gene caudal (cad) has a maternal embryonic function that establishes the antero-posterior body axis of Drosophila. It also has a conserved late embryonic and imaginal function related to the development of the posterior body region. Here we report the developmental role of cad in adult Drosophila. It is required for the normal development of the analia structures, which derive from the most posterior body segment. In the absence of cad function, the analia develop like the immediately anterior segment (male genitalia), following the transformation rule of the canonical Hox genes. We also show that cad can induce ectopic analia development if expressed in the head or wing. We propose that cad is the Hox gene that determines the development of the fly's most posterior segment. cad acts in combination with the Hedgehog (Hh) pathway to specify the different components of the analia: the activities of cad and of the Hh pathway induce Distal-less expression that, together with cad, promote external analia development. In the absence of the Hh pathway, cad induces internal analia development, probably by activating the brachyenteron and even-skipped genes.

Animals↗
PubMed1999

Lysosomal accumulation and recycling of lipopolysaccharide to the cell surface of murine macrophages, an in vitro and in vivo study.

In this study, we detailed in a time-dependent manner the trafficking, the recycling, and the structural fate of Brucella abortus LPS in murine peritoneal macrophages by immunofluorescence, ELISA, and biochemical analyses. The intracellular pathway of B. abortus LPS, a nonclassical endotoxin, was investigated both in vivo after LPS injection in the peritoneal cavity of mice and in vitro after LPS incubation with macrophages. We also followed LPS trafficking after infection of macrophages with B. abortus strain 19. After binding to the cell surface and internalization, Brucella LPS is routed from early endosomes to lysosomes with unusual slow kinetics. It accumulates there for at least 24 h. Later, LPS leaves lysosomes and reaches the macrophage cell surface. This recycling pathway is also observed for LPS released by Brucella S19 following in vitro infection. Indeed, by 72 h postinfection, bacteria are degraded by macrophages and LPS is located inside lysosomes dispersed at the cell periphery. From 72 h onward, LPS is gradually detected at the plasma membrane. In each case, the LPS present at the cell surface is found in large clusters with the O-chain facing the extracellular medium. Both the antigenicity and heterogenicity of the O-chain moiety are preserved during the intracellular trafficking. We demonstrate that LPS is not cleared by macrophages either in vitro or in vivo after 3 mo, exposing its immunogenic moiety toward the extracellular medium.

Animals↗
PubMed1999

Modulation of endocytosis in nuclear factor IL-6(-/-) macrophages is responsible for a high susceptibility to intracellular bacterial infection.

Activated macrophages kill bacteria, a function known to depend on the expression of NF-IL-6. Here, it is demonstrated that the attenuated Brucella abortus vaccine strain 19 replicates much better in NF-IL-6-/- than in NF-IL-6(+/+) and NF-IL-6(+/+)-activated murine macrophages and at levels comparable to those observed in normal macrophages infected with the pathogenic strain 2308. The role of NF-IL-6 in the inhibition of intracellular bacterial replication is related to its control of endocytosis and membrane fusion between endosomes and Brucella-containing phagosomes. Addition of the granulocyte-CSF (G-CSF), whose induction is impaired in NF-IL-6(-/-) macrophages, restores both endocytosis and the morphology of endosomes, together with bactericidal activity. Regulation of membrane traffic in endocytosis by G-CSF whose expression is controlled by NF-IL-6 may explain how a host cell can control intracellular bacterial replication.

Animals↗
PubMed1999

Experimental infection of mice with Yersinia enterocolitica serotype O9 by oral and parenteral routes: spreading and enterotropism of virulent yersiniae.

An isogenic pair of Yersinia enterocolitica serotype O9 strains, with and without virulence plasmid, was used to study the plasmid role in the infection of BALB/c mice by oral, intraperitoneal, and intravenous routes. The plasmid-bearing strain, but not its plasmid-less derivative, caused enteric infection after challenge by all three routes. The virulence plasmid did not influence the peritoneal clearance of yersiniae, but only the plasmid-bearing yersiniae were able to move from the peritoneal cavity to the bloodstream, and thus they spread to spleen and liver. Moreover, plasmid-bearing yersiniae were able to move from the liver to the gallbladder, and they shed in bile into the intestine. Western blot analysis of antibody responses to chromosomally encoded outer membrane proteins revealed similar patterns with sera from mice challenged with each one of two strains by intraperitoneal route. In contrast, only the plasmid-bearing strain elicited an antibody response to these antigens in mice challenged by oral route. Although mice experimentally infected with plasmid-bearing O9 yersiniae developed an enteric infection, irrespective of the inoculation route, differences between the first steps in infection by oral and parenteral routes may be important, especially when the infection model is used as an approach to study the yersinia-host interactions.

Animals↗
PubMed1999

Recipient factors as determinants of mortality after adult liver transplantation.

The factors that can influence the outcome of orthotopic liver transplantation (OLT) are numerous. The purpose of this study was to determine the effects of recipient preoperative factors on patient mortality. Between April 1986 and April 1998 a total of 600 OLTs were performed in our institution. We retrospectively reviewed our first 203 consecutive primary adult OLTs with at least 4 years of follow-up. A case-control comparison was performed between survivors and nonsurvivors, and differences in recipient variables were studied for their correlation with patient mortality. A logistic regression analysis was also performed. Mortality was significantly increased among those with fulminant hepatic failure (FHF) (66.6%, p = 0.003), primary cancer (63.1%, p = 0.018), females (46.1%, p = 0. 043), encephalopathy grade IV (72.7%, p = 0.012), recipients under respiratory support (69.2%, p = 0.031), and ABO-incompatible transplants (80%, p = 0.05). FHF, primary cancer, and female gender were the only variables that had a significant association with mortality in the logistic regression analysis. A higher incidence of prolonged respiratory support, bacterial and fungal infections, pneumonia, and chronic rejection contributed to the lower outcome observed in females. These results stress the need for continuous evaluation of the selection criteria of candidates for OLT suffering from primary cancer and FHF. The impact of recipient gender on mortality warrants further analysis but suggests that in the future more attention must be paid to the influence of this factor on the final outcome of OLT.

Adult↗
PubMed1999

The depth-of-field of the human eye from objective and subjective measurements.

The depth-of-field (DOF) measured through psychophysical methods seems to depend on the target's characteristics. We use objective and subjective methods to determine the DOF of the eye for different pupil diameters and wavelengths in three subjects. Variation of image quality with focus is evaluated with a double-pass technique. Objective DOF is defined as the dioptric range for which the image quality does not change appreciably, based on optical criteria. Subjective DOF is based on the accuracy of focusing a point source. Additional DOFs are obtained by simulation from experimental wavefront aberration data from the same subjects. Objective and subjective measurements of DOF are only slightly affected by pupil size, wavelength and spectral composition. Comparison of DOF from double-pass and wavefront aberration data allows us to evaluate the role of ocular aberrations and Stiles-Crawford effect.

Adult↗
PubMed1999

[The tilt-table test in assessing syncope of unknown origin: do differences exist between children and adults?].

BACKGROUND AND OBJECTIVES: Little is known about the differences between children and adults in the results of head-up tilt test. This study sought to investigate the potential differences concerning: a) the clinical profile and circumstances of spontaneous syncope; b) the overall diagnostic performance of the test, and c) the type of positive response obtained. MATERIAL AND METHODS: We studied 31 children and 123 adults with unexplained syncope. If baseline test (tilting at 70 degrees for 30 min) resulted negative, it was repeated under isoprenaline low-dose infusion. RESULTS: There were no differences in either clinical profile, except for severe traumatism more frequent in adults (25% vs. 3% in children; p < 0.05), or overall diagnostic performance (39% in children vs. 33% in adults; p = NS). However, the way the test rendered positive (via basal tilting in 92% of children vs. 50% in adults; p < 0.05) and the rate of cardioinhibitory response (42% in children vs 8% in adults; p < 0.01) were significantly different. CONCLUSIONS: In this study children, in contrast to adults, rarely have a positive response in tilting under isoprenaline infusion. They also present a much higher rate of cardio-inhibitory response than adults.

Adolescent↗