Biomedical subjects
Publications and source records attributed to C Muñoz.
The case of a 76-year-old patient with the Cronkhite-Canada syndrome admitted for diarrhea is presented. Although the clinical, endoscopical and histological data suggested the diagnosis, confirmation was achieved following necropsy, as well the evolution and the different treatment schedules carried out.
OBJECTIVE: To study the possible viral etiology in 139 infants with lower respiratory tract infection who required hospitalization in the Infant Unit of our hospital, from October 1994 to June 1995. PATIENTS AND METHODS: 139 patients were admitted, aged from 13 days to 14 months, during this period. The etiological agent was detected by direct immunofluorescence from nasopharyngeal secretions. Monoclonal antibodies were used against Respiratory Syncitial Virus, Influenza A Virus, Influenza B Virus, Adenovirus and Parainfluenza 3 Virus. Antibody detection against these viruses by Complement Fixation Test was done on 29 of these patients, with paired sera (acute and convalescent phase). RESULTS: In 82 patients (59%) we found at least one viral agents from the nasopharyngeal specimens, but in 64 of these only one was detected, in the remaining 18, there were more than one. Significant levels of antibodies were detected in only six of the 29 patients tested. Serology was negative in the remaining 23 patients. CONCLUSIONS: Syncitial Respiratory Virus is the first virus responsible for the lower respiratory tract infection in this age group (49%). There was no correlation between serological diagnosis and antigen detection.
A 44-year-old man diagnosed of common variable immunodeficiency associated with thrombopenia due to autoimmunity required anesthesia for anal fissure repair and hemorrhoidectomy. Hemostatic complications developed after surgery, with extreme thrombopenia (1,000 platelets/pl) and analytical changes that necessitated administration of six units of platelets from apheresis, as well as immunoglobulins, antifibrinolytic agents (e-aminocaproic acid) and granulocytic colony stimulating factors. Anesthesia for such patients is reviewed, with emphasis on careful management of the airways, preparation of sufficient material for surgery (rapid transfusion equipment, large caliber intravenous catheters, sterile material) and orientation of anesthetic technique toward general anesthesia through a laryngeal mask.
The leukocyte Ag CD69, one of the earliest cell surface activation Ags, is up-regulated at the transcriptional level by proinflammatory stimuli involving the NF-kappaB/Rel family of transcription factors. However, promoter fragments lacking a critical kappaB motif respond to other stimuli such as phorbol esters and triggering Abs against TCR/CD3. Since the 5' promoter flanking region of the CD69 gene contains several putative binding sequences for transcription factor activating protein-1 (AP-1), we explored its role in the inducible expression of CD69. Stimuli that induce AP-1, but not NF-kappaB, such as pyrrolidine dithiocarbamate, augmented the cell surface expression of CD69 as well as its mRNA levels, and the promoter activity of the CD69 gene. This up-regulation is accompanied by an increased binding of jun and fos family members to a consensus AP-1 binding site of the proximal (-16) CD69 promoter region, which seems to be functionally responsive to different activation signals and is trans activated by c-jun expression vectors. Furthermore, cotransfection of a dominant negative version of c-jun, but not IkappaB, abolished the inducible transcriptional activity of the CD69 promoter. In conclusion, the inducible expression of the CD69 gene by mitogenic signals is regulated by the transcription factor AP-1.
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BACKGROUND: To evaluate the frequency of Blastocystis hominis parasitation and to ascertain its role as an intestinal a prospective study during 18 months pathogen has been carried out. SUBJECTS AND METHODS: The study included 2,039 patients, which were classified in three groups (asymptomatic [group A], with suspicion of parasitosis [group B], with diarrhoea [group C]). In all cases a coproparasitological study was performed. In the group C the presence of non-parasitic enteropathogens was also investigated. In patients with B. hominis in the absence of other pathogens clinical and epidemiological characteristics were evaluated. Also, its was determined the morphology and quantification of parasites. RESULTS: Parasites were identified in 26.2% of population. B. hominis was identified in 336 patients (16.5%). The frequency of parasitation was superior in adults (p < 0.0001), with a slight predominance in the female sex. The rate of asymptomatic carriers was 3.3%. In 21 patients B. hominis (group C) was observed in absence of other enteropathogens. Statistical significant association was found between B. hominis, in absence of other pathogens and the presence of clinical manifestations (p < 0.0001), the most common of which were diarrhoea and abdominal pain. We did not find a statistically significant association between the number of B. hominis present and stool characteristics. The vacuolar form was the predominant morphological type. The ameboid form was observed only in diarrhoeal stools. CONCLUSIONS: B. hominis is the most frequent parasite found in faecal parasitological investigation. In absence of other causes, B. hominis must be considered as a pathogen.
Quinone redox cycling is generally known as an intracellular process that implies the reduction of quinones (Q) into semiquinones (Q-.) or hydroquinones (QH2), which autoxidize reducing oxygen to superoxide anion radical (O-.2). We demonstrate here for the first time the existence of quinone redox cycling in a ligninolytic fungus, Pleurotus eryngii, showing two particularities: extracellular production of O-.2 and involvement of ligninolytic enzymes. Experiments were performed with P. eryngii cultures, showing laccase activity, and four quinones: 1,4-benzoquinone (BQ), 2-methyl-1,4-benzoquinone (MeBQ), 2,3,5,6-tetramethyl-1,4-benzoquinone (duroquinone, DQ), and 2-methyl-1,4-naphthoquinone (menadione, MD). The overall process consisted of cell-bound divalent reduction of quinones, followed by extracellular laccase-mediated oxidation of hydroquinones into semiquinones, which autoxidized to a certain extent producing O-.2 (at the pH values of natural degradation of lignin, some autoxidation of hydroquinones was observed only with DQH2 and MDH2). The existence of a redox cyclic system involving quinones was evidenced by determining the chemical state of quinones along incubation under several conditions (either different O2 concentrations and pH values or laccase amounts). Thus, QH2/Q ratios at system equilibrium decreased as either pH values and oxygen concentration (allowing hydroquinones autoxidation) or the amount of laccase increased. Once the cyclic nature of the system was demonstrated, special attention was paid to the production of O-.2 during hydroquinone oxidation. Except in the case of BQH2, production of O-.2 was found in samples containing hydroquinones and laccase. By the use of agents promoting the autoxidation of semiquinones (superoxide dismutase and Mn2+), production of O-.2 during oxidation of BQH2 could finally be demonstrated.
The analysis of chromatin structure in cases of human spongiform encephalopathies could show the possible involvement of apoptosis in neuronal cell death. Genomic DNA was purified from peripheral blood lymphocytes and from a biopsy of the brain cortex in a case of Creutzfeldt-Jakob disease. Restriction fragment polymorphism with AspI, PvuII, Del and NspI showed the pattern of wild type PrP gene. The DNA purified from the brain consisted of partially degraded DNA in internucleosomal-sized fragments, whereas the DNA from peripheral blood lymphocytes showed the high molecular weight of unbroken DNA. These results are consistent with the possible activation in vivo of the apoptotic endonuclease and the internucleosomal fragmentation of DNA of the brain cortex in the patient affected by Creutzfeldt-Jakob disease, suggesting the involvement of apoptosis in neuronal cell death in human spongiform encephalopathy.
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The data on the relationship between iron deficiency and infection are conflicting. Some researchers conclude that mild iron deficiency is beneficial for immunity, whereas others contend that any deficit is not good for immunity. Additionally, infection or inflammation generate anemia and profound changes in iron metabolism mediated by cytokines. These changes are important confounders to consider in assessments of iron status.
Two laccase isoenzymes produced by Pleurotus eryngii were purified to electrophoretic homogeneity (42- and 43-fold) with an overall yield of 56.3%. Laccases I and II from this fungus are monomeric glycoproteins with 7 and 1% carbohydrate content, molecular masses (by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of 65 and 61 kDa, and pIs of 4.1 and 4.2, respectively. The highest rate of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) oxidation for laccase I was reached at 65 degrees C and pH 4, and that for laccase II was reached at 55 degrees C and pH 3.5. Both isoenzymes are stable at high pH, retaining 60 to 70% activity after 24 h from pH 8 to 12. Their amino acid compositions and N-terminal sequences were determined, the latter strongly differing from those of laccases of other basidiomycetes. Antibodies against laccase I reacted with laccase II, as well as with laccases from Pleurotus ostreatus, Pleurotus pulmonarius, and Pleurotus floridanus. Different hydroxy- and methoxy-substituted phenols and aromatic amines were oxidized by the two laccase isoenzymes from P. eryngii, and the influence of the nature, number, and disposition of aromatic-ring substituents on kinetic constants is discussed. Although both isoenzymes presented similar substrate affinities, the maximum rates of reactions catalyzed by laccase I were higher than those of laccase II. In reactions with hydroquinones, semiquinones produced by laccase isoenzymes were in part converted into quinones via autoxidation. The superoxide anion radical produced in the latter reaction dismutated, producing hydrogen peroxide. In the presence of manganous ion, the superoxide union was reduced to hydrogen peroxide with the concomitant production of manganic ion. These results confirmed that laccase in the presence of hydroquinones can participate in the production of both reduced oxygen species and manganic ions.
The analysis of short tandem repeats (STR) by PCR is a useful technique widely used in DNA identification. Some loci have alleles differing in the number of complete repeat units, whereas others are polymorphic with alleles differing even to the level of a single base. Minor differences in the sequence of STR can confuse the analysis when the PCR product are poorly resolved in denaturing PAGE. The study by SSCP of STR in loci CSF1PO, TPOX, and THO1 and the alleles of locus DIS80 is shown in a representative case of paternity dispute. The analysis of short tandem repeats (STR) by the conformation polymorphisms of single-stranded DNA (SSCP) clearly enhanced the degree of resolution. The high resolution of SSCP of the STR may be the result of the arrangement of very prominent secondary structure and conformation due to the primary repetitive sequence. The method may be of particular interest to distinguish STR with similar PAGE mobility under denaturing conditions and to distinguish tandem repeats of the same size but different sequence.
BACKGROUND: Coronary bypass grafts made with internal mammary artery have better long-term results than those made with saphenous vein. It is possible that the use of both mammary arteries would lead to even better results. AIM: To compare the long-term survival and the incidence of new coronary events of patients, in whom one or two mammary arteries were used as coronary bypass grafts. PATIENTS AND METHODS: One hundred and eight randomly selected patients who received one mammary artery for myocardial revascularization and 108 patients, matched for prognostic factors, who received two mammary arteries were studied. These patients were followed for a mean of 4 years (range 1 to 12 years). Operative complications, hospital mortality and long-term probability of being free of disease were compared in both groups. RESULTS: Operative mortality was similar in both groups (0.9%). Patients that received two mammary arteries had a higher frequency of operative wound complications. Long-term survival was 84% in patients who received one and 83% in patients who received two mammary arteries. The probabilities of being free of myocardial infarction (92 and 82% respectively) and angina (94 and 86% respectively) were lower in the later group. CONCLUSIONS: Patients who received two mammary arteries had a higher probability of a long term disease free survival than patients who received one mammary artery.
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OBJECTIVE: The purpose of this study was to evaluate the usefulness of the technique of polymerase chain reaction (PCR) for the diagnosis of tuberculosis in the pediatric population. PATIENTS AND METHODS: All patients seen at the University Hospital Sant Joan de Déu in Barcelona during the year of 1995 in which there was a clinical suspicion of or an interest in discarding tuberculosis were studied. Two types of diagnoses were considered: 1) Diagnosis from clinical evidence without microbiological confirmation, 2) A certain diagnosis including microbiological confirmation. All samples received at the microbiology laboratory were processed by baciloscopy, culture and PCR, Amplicor PCR M. tuberculosis was used as the PCR method. RESULTS: Sixty-four samples (most of them gastric juices) from 41 children were processed during the study period. Fourteen patients, between 8 months and 17 years of age, were diagnosed of tuberculosis, Microbiological confirmation by culture and/or PCR was obtained in four patients (31%). PCR was the only positive technique in one child (staining and culture negative) with clinical evidence of tuberculosis. All samples from the other three patients that had positive cultures also had positive PCR results. False positives were not detected. CONCLUSIONS: PCR improves the diagnosis of pediatric tuberculosis. It stands out because of its quickness (possibility of a 9 hour turn-around time), sensitivity (slightly higher than cultures in our series) and specificity.
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Endothelial cells (EC) play a key role in the inflammatory response, both by the production of proinflammatory cytokines and by their interaction with leukocytes. Molecular genetic analysis has demonstrated that functional NF-kappa B sites are involved in the transcription of interleukin-6 (IL-6), IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) genes in response to inflammatory mediators. Thus, we have explored the effect of two inhibitors of the NF-kappa B activation, pyrrolidine dithiocarbamate (PDTC) and N-acetylcysteine (NAC), on the production of these cytokines by EC. Both PDTC and NAC inhibited, in a dose-dependent manner, the synthesis of IL-6, IL-8, and GM-CSF induced by tumor necrosis factor (TNF)-alpha or bacterial lipopolysaccharides (LPS) in human umbilical vein endothelial cells (HUVEC). PDTC appeared to prevent IL-6, IL-8, and GM-CSF gene transcription, as it blocked the induction of specific mRNA by TNF-alpha or LPS. The TNF-alpha mediated transcriptional activation of a chloramphenicol acetyltransferase (CAT) plasmid containing three copies of the -72 kappa B binding site from the IL-6 promoter was abrogated by PDTC. According to transfection experiments, electrophoretic mobility shift assays (EMSA) demonstrated that the antioxidant prevented the induction of NF-kappa B DNA-binding activity by TNF-alpha. Under the same conditions, PDTC by itself or in combination with TNF-alpha, enhanced the DNA-binding activity of AP-1, as well as c-fos and c-jun mRNA levels. Altogether, these results indicate that the antioxidant PDTC specifically inhibits the transcription of IL-6, IL-8, and GM-CSF genes through the inhibition of the NF-kappa B activation, while increasing the expression of AP-1. Our data make evident the antiinflammatory and immunoregulatory potential of the pharmacological inhibition of the NF-kappa B activation. In addition, PDTC and related molecules may be a useful tool to explore the expression of genes involved in the inflammatory response.