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Biomedical subjects

E Moreno

Publications and source records attributed to E Moreno.

At least 163 records · Page 9Linked to original sources
PubMed1994

The O-chain of Brucella abortus lipopolysaccharide induces SDS-resistant MHC class II molecules in mouse B cells.

LPS is the most important antigen of Brucella bacteria which are gram-negative facultative intracellular pathogens infecting a large proportion of animals and humans in the world. In order to get insights into the immune response mechanisms monitored by Brucella, its LPS was used as a model antigen. S-LPS, R-LPS, lipid A and O-chain purified from Brucella abortus were tested in their capacity of inducing SDS-resistant MHC class II molecules after incubation with murine B lymphoma cells. S-LPS and O-chain gave a significant response suggesting that O-chain might induce an association with class II itself or might act as a carrier for antigens to bind MHC class II molecules.

Animals↗
PubMed1994

Etiopathogenesis and prognosis of centrilobular necrosis in hepatic grafts.

The incidence, contributing etiopathogenetic factors, and prognostic significance of centrilobular necrosis were investigated in 270 hepatic transplants to 215 immunosuppressed patients in whom 837 biopsies were performed. Twenty-six (9.6%) grafts demonstrated centrilobular necrosis in one or more biopsy specimens. The immunological, clinical, histopathological, and evolutionary features of this patient group (group A) were compared with a control group of patients who had undergone 92 consecutive transplants with no necrosis (group B). Group A was younger (p < 0.01), had a higher average of warm and cold-ischemia time (p < 0.05), a higher incidence (p < 0.001) and earlier appearance of acute rejection episodes (p < 0.01), and a closer association with evolution to chronic rejection (A: 53.8% vs B: 13.1%, p < 0.001). Survival rates for grafts and patients with necrosis at 12 and 30 months were significantly lower (p < 0.001). The 26 grafts were distributed into three chronological subgroups according to when necrosis appeared: (1) First week--All these grafts were lost (four through primary graft nonfunction and one due to protal recurrent thrombosis); (2) Second week--seven grafts with associated acute rejection, with three evolving to chronic rejection; (3) After the second week (116 +/- 82 days)--five with isolated necrosis, two with associated acute rejection, four with associated ductopenia, and three with associated acute rejection and ductopenia. In 11 grafts the necrosis persisted and evolved to chronic rejection. In conclusion, these findings indicate that centrilobular necrosis is a histopathological sign associated with poor prognosis in most hepatic grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Photorefractive keratectomy after radial keratotomy.

We report the results of a prospective study that evaluated the efficacy, predictability, and safety of excimer laser photorefractive keratectomy (PRK) to correct residual myopia after radial keratotomy (RK). Using a 193 nm excimer laser, we performed PRK on ten undercorrected myopic eyes that had previous RK surgery. The mean interval between the RK and PRK was 1.5 years. Mean follow-up was seven months. Mean preoperative refraction was -4.08 +/- 1.35 diopters (D) and after PRK was +1.61 +/- 1.18 D at three months, +1.05 +/- 0.75 D at six months, and +0.79 +/- 0.83 D at 12 months. An uncorrected visual acuity of 20/40 or better was achieved in eight eyes at three months, seven eyes at six months, and three eyes at 12 months. One eye had a transient loss of two Snellen lines of best spectacle corrected visual acuity because of increased haze. No other significant complication was noted. Our study shows that PRK is a predictable, effective, stable, and safe technique to correct residual myopia after RK. The results were similar to those of PRK without prior surgery, although we noted a slightly greater hyperopic deviation. We believe that eyes undercorrected by RK may benefit from subsequent PRK.

Adult↗
PubMed1994

Amputation neuroma of the hepatic hilum after orthotopic liver transplantation.

Amputation neuromas following biliary surgery have been previously reported. There are no descriptions, however, of amputation neuroma following liver transplantation. Serial hilum sections taken from 93 hepatectomy specimens obtained during the clinical course of 262 consecutive orthotopic liver transplantations revealed 26 amputation neuromas (27.9% of the specimens examined). The finding was confirmed by immunohistochemistry with numerous S-100 protein positive cells intermingled with neurofilaments interrupting the perineurial layer of cells testing positive for epithelial membrane antigen. Neuromas were found in liver specimens obtained between 89 and 775 days post-transplant (mean time, 211 days). The incidence of neuroma was higher in specimens resected more than 3 months post-transplant. There was only one symptomatic patient, who died from extrahepatic cholestasis demonstrated at autopsy to be caused by a hilar neuroma obstructing the main bile duct.

Humans↗
PubMed1994

Chromosome-mediated resistance of Yersinia enterocolitica serotype O9 to intracellular killing by mouse peritoneal macrophages.

The survival of Yersinia enterocolitica serotype O9 within mouse peritoneal macrophages was investigated. To evaluate the role of the virulence plasmid in the resistance to intracellular killing, an isogenic pair of virulent (plasmid-bearing) and avirulent (plasmid-less) O9 strains was used. The virulent strain was able to express plasmid-encoded outer membrane proteins and to colonize the Peyer's patches of orally infected mice. When mice were infected intraperitoneally, both strains were recovered at similar rates and over the same time from the peritoneal cavity. When in vitro assays were performed, both strains showed similar resistance to intracellular killing by monolayers of resident and inflammatory peritoneal macrophages. Previous opsonization of bacteria did not modify their survival within macrophage monolayers. We concluded that serotype O9 strains display a chromosome-mediated resistance to intracellular killing by mouse peritoneal macrophages. Moreover, macrophage resistance does not seem to be of importance for virulence of serotype O9 strains in mice.

Animals↗
PubMed1994

Immunochemical identification of Brucella abortus lipopolysaccharide epitopes.

Sera from Brucella abortus-infected and -vaccinated bovines recognized four lipopolysaccharide (LPS) determinants: two in the O-polysaccharide (A and C), one in the core oligosaccharide from rough Brucella LPS (R), and one in lipid A (LA). From 46 different hybridomas secreting monoclonal antibodies (MAbs) against various LPS moieties, 9 different specificities were identified. Two epitopes, A and C/Y, were present in the O-polysaccharide. Two epitopes were found in the core oligosaccharide (R1 and R2) of rough Brucella LPS. MAbs against R1 and R2 epitopes reacted against LPS from different rough Brucella species; however, MAbs directed to the R2 epitope also reacted against enterobacterial LPS from deep rough mutants. Three epitopes (LA1, LA2, and LA3) were located in the lipid A backbone. Different sets of MAbs recognized two epitopes in the lipid A-associated outer membrane protein (LAOmp3-1 and LAOmp3-2). LPS preparations from smooth brucellae had small amounts of rough-type LPS. Although LPS from rough brucellae did not show smooth-type LPS in western blots (immunoblots), two hybridomas generated from mice immunized with rough B. abortus produced antibodies against smooth B. abortus LPS. Results are discussed in relation to the structure and function of B. abortus LPS and to previous findings on the epitopic density of the molecule.

Animals↗
PubMed1994

Antimicrobial activity of natural and semisynthetic diterpenoids from Sideritis spp.

The antimicrobial activity of 22 natural diterpenoids of endemic Sideritis from Eastern Andalusia (Spain) is described. Only ent-kaur-16-ene foliol and ent-beyer-15-ene isopusillatriol proved to be active towards Gram-positive and acid-fast bacteria. The introduction of a ketonic group at C-15 on ent-kaur-16-enic systems produced a remarkable degree of activity.

Anti-Bacterial Agents↗
PubMed1993

In vivo inactivation of the yeast plasma membrane ATPase in the absence of exogenous catabolism.

Yeast plasma membrane ATPase is inactivated up to 80% in the absence of catabolism of exogenous nutrients (exogenous catabolism). This inactivation, that is not accompanied by a decrease in the cellular content of ATPase, is due to an irreversible decrease of the Vmax and does not require protein synthesis. The inactivated enzyme maintains the ability to be regulated by fermentable sugars but shows important alterations in the characteristics of this regulation. Upon addition of glucose, the Vmax of the inactivated enzyme increases as well as its Ki for vanadate but, in contrast to the normal enzyme, its affinity for ATP or its pH optimum do not increase. It is concluded that in the absence of exogenous catabolism an irreversible modification of the yeast plasma membrane ATPase takes place that affects several of its kinetic properties.

Cell Membrane↗
PubMed1993

Neurologic complications in liver transplantation.

A retrospective review is presented of neurologic complications in our first 143 consecutive adult patients (208 liver transplants in 143 adults and 18 children) undergoing liver transplantation. Nineteen (13.2%) of the 143 patients developed neurologic complications in the postoperative period. Immunosuppression was initiated intraoperatively with steroids with the addition of azathioprine on Day 1 and cyclosporine, adjusted by RIA to a level of 400-600 ng/ml, on Day 2 post-transplantation. Azathioprine is discontinued in the third month. Fourteen of the 19 patients (73.6%) presented with CNS complications characterized by: diffuse multifactorial encephalopathy (5 patients); leukoencephalopathy (2 patients) which required temporary (1 case) or permanent (1 case) discontinuation of cyclosporine A; hemorrhage (in 2 cases due to arterial hypertension and coagulopathy and another due to unknown causes); ischemic/anoxic injury secondary to cardiorespiratory arrest (2 patients) or arteriothrombosis (1 patient); and myelopathy (1 patient) due to vertebral compression (T10-T11) secondary to osteoporosis. The diagnostic studies most often employed were computed tomographic (CT) (85.7%) and electroencephalography (EEG) (42.8%). Five of 19 patients (26.3%) suffered peripheral nervous system (PNS) complications: 1 patient with reversible Claude-Bernard-Horner Syndrome caused by central venous catheterization during anesthesia; 2 patients with peroneal nerve palsy due to compression below the knees by operating room table supports; 1 patient with an irreversible lesion of the right recurrent laryngeal nerve secondary to prolonged intubation and central venous catheterization; and 1 patient with a reversible lesion of the left brachial plexus secondary to inadvertant hyperextension of the upper extremity on the O.R. table due to the need for dialysis and catheterization of the axillary vein for veno-venous bypass.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Ganciclovir prophylaxis decreases frequency and severity of cytomegalovirus disease in seropositive liver transplant recipients treated with OKT3 monoclonal antibodies.

The efficacy of ganciclovir, given prophylactically, to prevent cytomegalovirus-related disease was evaluated in liver transplant recipients, mostly seropositive, under treatment with OKT3 monoclonal antibodies. The incidence of cytomegalovirus disease and visceral involvement was reduced, respectively, from 52 and 36% in the control group to 12 and 8% in the ganciclovir-treated patients. Leukopenia was a frequent (32%) side effect of ganciclovir administration.

Adult↗
PubMed1993

Comparative analysis of Brucella serotype A and M and Yersinia enterocolitica O:9 polysaccharides for serological diagnosis of brucellosis in cattle, sheep, and goats.

Hapten polysaccharides of Brucella smooth M and A serotypes were prepared from Brucella sp. and Yersinia enterocolitica O:9 by previously described hydrolytic (O chain) or nonhydrolytic (native hapten [NH]) procedures. The purified polysaccharides differed only in the presence (O chain) or absence (NH) of lipopolysaccharide core sugars. The polysaccharides were compared by reverse radial immunodiffusion for the diagnosis of brucellosis in cattle (Brucella abortus biotype 1 [A serotype] and Brucella melitensis biotype 3 [AM serotype]), sheep (B. melitensis biotypes 1 [M serotype] and 3), and goats (B. melitensis biotype 1). The reverse radial immunodiffusion test with the NH from B. melitensis 16 M (serotype M) showed the highest sensitivity (89.6 to 97.3%), regardless of the host species and the serotype of the infecting Brucella sp. Y. enterocolitica O:9 NH (A serotype) was useful for diagnosing disease in cattle infected with B. abortus biotype 1, but not in cattle infected with B. melitensis biotype 3, sheep, or goats. The different results obtained with the serotype M and A polysaccharides and the sera from animals infected with M, A, and AM serotypes of Brucella spp. showed that in naturally infected animals, a large proportion of the antibodies are directed to or react with a previously defined common epitope(s) (J. T. Douglas and D. A. Palmer, J. Clin. Microbiol. 26:1353-1356, 1988) different from the A or M epitopes. By using the radial immunodiffusion test with B. melitensis 16M NH, it was possible to differentiate infected from vaccinated cattle, sheep, and goats with a sensitivity and specificity similar to that of the complement fixation test.

Animals↗
PubMed1992

[Prospective study of cytomegalovirus infection in liver transplant recipients].

BACKGROUND: Cytomegalovirus (CMV) infection is an important cause of morbidity and mortality in liver transplant recipients. The aim of this study was to determine the incidence, clinical characteristics, risk factors and response to treatment of CMV infection in liver transplant recipients. METHODS: Fifty-nine adult patients who underwent a liver transplant in our hospital were prospectively studied. Cell cultures were used to document CMV infection and disease. Ganciclovir treatment was only given to patients with documented CMV disease. RESULTS: Active infection was shown in 47 of 59 patients (80%), and symptomatic infection (disease) in 17 (29%). The most frequent clinical presentation was hepatitis (9 cases) followed by flu-like syndrome (6 cases) and pneumonitis (4 cases). The average time from transplant to the diagnosis of CMV disease was 36 days. The seronegative recipients of seropositive donors developed symptomatic infection more frequently (66%) than other patients (p < 0.05). As well as the CMV serologic status before transplantation, the use of anti-OKT3 antibodies was the only risk factor related to CMV disease (p < 0.01). The treatment with ganciclovir was successful in 17 of 19 symptomatic episodes. CONCLUSIONS: Active and symptomatic CMV infection in recipients of liver transplantation were very frequent in our study. The transplant from seropositive to seronegative and the use of anti-OKT3 antibodies increased the incidence of CMV disease. Ganciclovir appeared as a safe and, apparently, highly efficient drug.

Adult↗
PubMed1992

Inhibition of glycolysis by 2-deoxygalactose in Saccharomyces cerevisiae.

The enzymatic steps involved in the inhibition of glycolysis by 2-deoxygalactose in Saccharomyces cerevisiae have been investigated. Yeast, incubated with 2-deoxygalactose, accumulates up to 8 mM-2-deoxygalactose, 30 mM-2-deoxygalactose-1-phosphate and 0.25 mM-UDP-2-deoxygalactose and UDP-2-deoxyglucose. An inverse correlation between 2-deoxygalactose-1-phosphate content and rate of glycolysis has been observed. The intracellular concentration of glycolytic intermediates and related metabolites point to the hexokinase and phosphofructokinase steps as the targets for the inhibition of glycolysis by 2-deoxygalactose and rule out all other mechanisms that have been proposed to explain this inhibition.

Adenosine Triphosphate↗