PubMed Health⌕ Search

Biomedical subjects

E Muñoz

Publications and source records attributed to E Muñoz.

At least 55 records · Page 3Linked to original sources

[Macromolecular creatinine kinase in patients diagnosed with ulcerative colitis].

Macromolecular creatinine kinase (macro-CK) type 1 is a macroenzyme formed by the union of an immunoglobulin with a creatinine kinase (CK) enzyme. Its presence in the blood may lead to misdiagnosis of heart disease. This macromolecule has been described in various diseases and is relatively more frequent those with autoimmune etiology. We describe three cases of ulcerative colitis that presented elevated MB-isoenzyme of CK activity greater than the total CK quantified by the immunoinhibition method. Electrophoresis revealed an atypical band that corresponded with the presence of a type 1 macroenzyme. Detection of this macromolecule could be useful in cases of ulcerative colitis when results of blood testing lead to suspicion of ischemic disease.

Adult↗

Polyomavirus enhancer-binding protein 2/core binding factor/acute myeloid leukemia factors contribute to the cell type-specific activity of the CD11a integrin gene promoter.

The CD11a/CD18 leukocyte integrin (LFA-1; also known as alphaL/beta2) mediates leukocyte transendothelial migration during immune and inflammatory responses and participates in lymphoma metastasis. CD11a/CD18 leukocyte-restricted expression is controlled by the CD11a gene promoter, which confers tissue-specific expression to reporter genes in vitro and in vivo. DNase I protection analysis of the CD11a proximal gene promoter revealed DNA-protein interactions centered at position -110 (CD11a-110). Disruption of CD11a-110 reduced CD11a promoter activity in a cell type-specific manner, as it reduced its activity by 70% in Jurkat lymphoid cells, whereas the effect was considerably lower in K562 and HepG2 cells. Electrophoretic mobility shift assays showed evidence of cell type-specific differences in CD11a-110 binding and indicated its specific recognition by members of the polyomavirus enhancer-binding protein 2/core binding factor (CBF)/acute myeloid leukemia (AML) family of transcription factors. AML1B/CBFbeta transactivated the CD11a promoter, with AML1B/CBFbeta-mediated transactivation being completely dependent on the integrity of the CD11a-110 element. Therefore, CBF/AML factors play a role in the cell type-restricted transcription of the CD11a integrin gene through recognition of CD11a-110. The involvement of CBF/AML factors in CD11a expression raises the possibility that CD11a/CD18 expression might be deregulated in acute myeloid and B-lineage acute lymphoblastic leukemias, thus contributing to their altered adhesion and metastatic potential.

CCAAT-Enhancer-Binding Proteins↗

A new mutation in the parkin gene in a patient with atypical autosomal recessive juvenile parkinsonism.

We have investigated the presence of mutations in the parkin gene in patients with early-onset parkinsonism. Direct sequencing of the polymerase chain reaction (PCR) products showed a homozygous G deletion in the exon 7 (c.871delG) in one patient. This was a 38-year-old Moroccan woman with a history of parkinsonism of 18 years of duration. The disease appeared as an apparently sporadic case and was characterized by dystonia of the legs at onset and a rapid progression to severe generalized parkinsonism but with an excellent maintained response to dopamine agonists treatment. The deletion was a frameshift mutation resulting in a stop codon at position 297 which causes truncation of the parkin protein. Mutations in the parkin gene can be encountered in patients with an apparently sporadic early-onset parkinsonism, rapidly progressive course and marked and maintained response to dopamine agonists.

Adult↗

Involvement of mitochondria and caspase-3 in ET-18-OCH(3)-induced apoptosis of human leukemic cells.

The induction of cell death in leukemic HL-60 cells by the ether lipid 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH(3); edelfosine) followed the typical apoptotic changes in ultrastructural morphology, including blebbing, chromatin condensation, nuclear membrane breakdown and extensive vacuolation. Using a cytofluorimetric approach, we found that ET-18-OCH(3) induced disruption of the mitochondrial transmembrane potential (DeltaPsi(m)) followed by production of reactive oxygen species (ROS) and DNA fragmentation in leukemic cells. ET-18-OCH(3) also induced caspase-3 activation in human leukemic cells, as assessed by cleavage of caspase-3 into the p17 active form and cleavage of the caspase-3 substrate poly(ADP-ribose) polymerase (PARP). ET-18-OCH(3) analogues unable to induce apoptosis failed to disrupt DeltaPsi(m) and to activate caspase-3. ET-18-OCH(3)-resistant Jurkat cells generated from sensitive Jurkat cells showed no caspase-3 activation and did not undergo DeltaPsi(m) disruption upon ET-18-OCH(3) incubation. Cyclosporin A partially inhibited DeltaPsi(m) dissipation, caspase activation and apoptosis in ET-18-OCH(3)-treated leukemic cells. Overexpression of bcl-2 by gene transfer prevented DeltaPsi(m) collapse, ROS generation, caspase activation and apoptosis in ET-18-OCH(3)-treated leukemic T cells. Pretreatment with the caspase inhibitor Z-Asp-2, 6-dichlorobenzoyloxymethylketone prevented ET-18-OCH(3)-induced PARP proteolysis and DNA fragmentation, but not DeltaPsi(m) dissipation. ET-18-OCH(3) did not affect the expression of caspases and bcl-2-related genes. ET-18-OCH(3)-induced apoptosis did not require protein synthesis. Our data indicate that DeltaPsi(m) dissipation and caspase-3 activation are critical events of the apoptotic cascade triggered by the antitumor ether lipid ET-18-OCH(3), and that the sequence of events in the apoptotic action of ET-18-OCH(3) on human leukemic cells is: DeltaPsi(m) disruption, caspase-3 activation and internucleosomal DNA degradation.

Antineoplastic Agents↗

[Estimate of HIV-1 infection prevalence in pregnant women and effectiveness of zidovudine administered during pregnancy in the prevention of vertical transmission].

BACKGROUND: Despite the proven efficacy of zidovudine (ZDV) for reducing perinatal transmission of HIV-1, questions remain about its implementation and effectiveness in routine practice. The aims of this study were to assess the impact of ZDV administered during pregnancy in preventing perinatal HIV-1 transmission, and to determine the proportion of early identification of maternal HIV-1 infection over time. PATIENTS AND METHODS: We prospectively followed from birth a cohort of children born between 1/1/1987 and 31/10/1997 to HIV-1-infected mothers. Infant infection status was assessed by follow-up beyond 18 months or HIV-PCR up to 3 months of age. RESULTS: 229 mothers and 248 infants were identified in the cohort. ZDV was administered during pregnancy as monotherapy to 34 mothers for a mean of 4.7 (3.1) months prior to delivery. There were no differences in baseline characteristics between the treated and untreated groups. Mean (SD) CD4 cell count was 465 (261) cells x 10(6)/l. Factors associated with transmission were a more prolonged time of rupture of obstetric membranes (median 6 vs 1.04 hours; p = 0.023) and ZDV treatment. Among the ZDV-treated mothers only one child was infected (2.9%), whereas 37 children born to 212 untreated women became infected. (OR: 0.14; 95% CI: 0.07-0.92). The estimated prevalence of HIV-1 in pregnant women in our area is about 0.39% (95% CI: 0.34-0.45). From 1987 to 1991, 9.7% of infected women were nor identified at the perinatal period, as compared to 2.5% in the last 5 years of the study period (p = 0.034). CONCLUSIONS: In this study, the estimated prevalence of HIV-1 infection is high. ZDV during pregnancy is significantly associated with a decrease in perinatal transmission in our setting. The awareness of an effective treatment might have contributed to the increased identification of HIV-infected mothers prior to delivery observed over time in our cohort of children born to HIV-infected mothers.

Adolescent↗

Identification of a functional NF-kappa B site in the platelet endothelial cell adhesion molecule-1 promoter.

Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a type I transmembrane adhesion protein of 130 kDa that belongs to a subgroup of the Ig gene superfamily, characterized by the presence of immunoreceptor tyrosine-based inhibitory motifs. PECAM-1 is expressed in circulating platelets, monocytes, neutrophils, a selective subgroup of T cells, and in endothelial cells, where it is preferentially located at intercellular junctions and participates in leukocyte transmigratory processes. The identification of two consensus NF-kappa B sites within the PECAM-1 promoter led us to analyze their possible involvement in the PECAM-1 expression regulated by inflammatory stimuli. We found that surface expression and promoter activity of PECAM-1 in myeloid cells are regulated by modulators of NF-kappa B, including TNF-alpha, PMA, and pyrrolidine dithiocarbamate. Mobility shifts assays identified a specific NF-kappa B-binding element at +110/+120, whose mutation abolished the basal promoter activity of PECAM-1 and decreased NF-kappa B-dependent responses of the PECAM-1 gene promoter. Furthermore, cotransfection experiments with an expression vector encoding the p65 subunit of NF-kappa B showed transactivation of the PECAM-1 promoter. These results demonstrate that NF-kappa B can regulate the transcriptional activity of PECAM-1.

5' Untranslated Regions↗

c-Myc inhibits CD11a and CD11c leukocyte integrin promoters.

The c-Myc transcription factor is an important regulator of cell growth and differentiation, and its gene repression ability seems to play a key role in Myc-mediated cellular transformation. Since Myc overexpression has been associated with reduced expression of beta1 and beta2 integrins, we have investigated the role of c-Myc on CD11a and CD11c transcription. c-Myc inhibited CD11a and CD11c integrin promoter activity in co-transfection experiments, and similar repression was obtained in cells where c-Myc expression (KmycB) or activity (Rat-1 c-MycER) is inducible. The c-Myc repression on the CD11c promoter was independent of the USF-binding site (USF-150), other putative Myc-binding elements, or the integrity of the initiator (Inr)-like sequence present at the major transcriptional start site. Analysis of deletion and mutant promoter constructs revealed that, in the absence of additional upstream cisacting elements, an AP-1-binding site at -60 (AP1-60) is required for c-Myc repressor activity. The c-Myc repressor activity on both integrin promoters was abrogated by deletion of c-Myc residues 106-143, a domain involved in Inr-dependent transcriptional repression. These results demonstrate a direct effect of c-Myc on integrin gene transcription and suggest the existence of a c-Myc-dependent mechanism for coupling leukocyte integrin expression to the cell proliferative state.

Cell Line↗

Progressive multifocal leukoencephalopathy following oral fludarabine treatment of chronic lymphocytic leukemia.

Progressive multifocal leukoencephalopathy (PML) is a subacute demyelinating disorder of the central nervous system usually affecting immunocompromised individuals and is due to infection of the oligodendrocytes by the JC virus. A case of PML in a chronic lymphocytic leukemia (CLL) patient treated with fludarabine is reported, representing the second such instance in which the diagnosis of the neurological disorder was established by brain biopsy. A 61-year-old man with a 14-year history of B-cell type CLL, for which he had received chlorambucil therapy 10 years earlier, developed progressive paresis of both left extremities at 7 months of receiving low doses of oral fludarabine, when his CD4 count has decreased to 0.08 x 10(9)/l. Cranial magnetic resonance imaging revealed a subcortical focal lesion at the right precentral gyrus and a focal lesion at the right thalamus, and a stereotactic brain biopsy showed pathological findings consistent with PML, namely severe myelin breakdown, reactive astrocytosis, and abnormal, huge glial cells with large bizarre nuclei showing granular basophilic inclusions, whereas the presence of the JC virus was demonstrated by in situ hybridization. The present case, in addition to a few previously reported, calls attention to the possibility that severe neurological side effects can be associated with the immunosuppression provoked by the use of fludarabine in CLL patients.

Administration, Oral↗

Lithium effect on testicular tissue and spermatozoa of viscacha (Lagostomus maximus maximus). A comparative study with rats.

We investigated the effect of lithium chloride administration (Sigma): 1 mmol/kg b.w. i.p./day for 35 days on the testes and sperm of viscacha (Lagostomus maximus maximus), a nocturnal rodent found only in the pampas of Argentina. The histological study showed that hypospermatogenesis and the sperm number per mL decreased markedly in comparison with the controls (treatment group: 315 x 10(6) +/- 77 x 10(6); control group: 693 x 10(6) +/- 39 x 10(6), Means +/- SEM, Student's t-test: p < 0.05). The sperm motility and viability were also affected. Under the same treatment, the testicular tissue and the sperm of rats were not damaged. Moreover, lithium induced these changes when the plasm levels were within the therapeutic range in humans. Our results provide evidence for the claim that viscacha testes and sperm react very sensitively to low doses of lithium, whereas these concentrations do not produce damage in rats.

Animals↗

Phorboid 20-homovanillates induce apoptosis through a VR1-independent mechanism.

BACKGROUND: Vanilloids, such as capsaicin and resiniferatoxin (RTX), are recognized at the cell surface by vanilloid receptor type 1 (VR1), which has recently been cloned. VR1 mediates the effects of capsaicin and RTX in VR1-expressing cells, but vanilloids can induce apoptosis through a pathway not mediated by VR1. Phorboid 20-homovanillates can be used to investigate cell death induced by vanilloids. RESULTS: 12,13-Diacylphorbol-20 homovanillates were prepared by the sequential esterification of the natural polyol. Phorbol 12-phenylacetate 13-acetate 20-homovanillate (PPAHV) induced apoptosis in Jurkat cells to the same extent as RTX. Apoptosis was preceded by an increase in intracellular reactive oxygen species and by the loss of mitochondrial transmembrane potential. PPAHV-induced apoptosis was mediated by a pathway involving caspase-3 activation and was initiated at the S phase of the cell cycle. The cell-death pathway triggered by VR1 activation was studied in 293T cells transfected with the cloned rat vanilloid receptor. In this system, capsaicin and PPAHV induced cell death by an apparent necrotic mechanism, which was selectively inhibited by the competitive vanilloid receptor antagonist capsazepine. Interestingly, phorbol-12, 13-bisnonanoate-20-homovanillate, an analogue of PPAHV, induced cell death in VR1-transfected cells but could not trigger apoptosis in the Jurkat cell line. CONCLUSIONS: Vanilloids can induce cell death through different signalling pathways. The cell death induced in a VR1-independent manner has the hallmark of apoptosis, whereas the cell death mediated by vanilloids binding to VR1 is seemingly necrotic. Phorboid homovanillates that have antitumour and anti-inflammatory activities but lack the undesirable side effects of the natural vanilloids could be developed as potential drugs.

Apoptosis↗

Can some cases of 'possible' spondyloarthropathy be classified as 'definite' or 'undifferentiated' spondyloarthropathy? Value of criteria for spondyloarthropathies. Spanish Spondyloarthropathy Study Group.

OBJECTIVES: When evaluating patients for spondyloarthropathy, clinicians use the 'possible spondyloarthropathy' category to indicate that they are unsure about the diagnosis. We sought to determine whether Amor's criteria or the European Spondyloarthropathy Study Group (ESSG) criteria could lift thi uncertainty. PATIENTS AND METHODS: During a Spanish study designed to validate criteria for spondyloar thropathies, 102 patients were classified in the 'possible spondyloarthropathy' category. We divided these patients into subgroups based on whether or not they met criteria for spondyloarthropathy. We compare baseline characteristics (N = 102) and five-year outcomes (N = 52) in these subgroups. RESULTS: The following features were significantly more common in the subgroups of patients who met Amor's criteria for spondyloarthropathy: oligoarthritis, heel pain, uveitis, balanitis, family history of spondyloarthropathy, an presence of the HLA B27 antigen. No differences were found for age at symptom onset, disease duration, buttock pain, gender, dactylitis, diarrhea, or psoriasis. Of the 52 patients followed up for five years, 17 me Amor's criteria at baseline and 13 were subsequently found to have definite spondyloarthropathy, whic was undifferentiated in six cases. There were only three cases of spondyloarthropathy among the 2 patients who did not meet Amor's criteria at baseline. Of the 28 patients who met ESSG criteria at baseline, 13 had spondyloarthropathy versus three of the 17 patients who did not meet ESSG criteria at baseline CONCLUSION: Amor's criteria or the ESSG criteria allow early classification of most patients with 'possible spondyloarthropathy' and early identification of undifferentiated spondyloarthropathy corresponding to minimal-symptom or incipient disease. In this study, Amor's criteria performed better than the ESSG criteria.

Adult↗

Fitness effect analysis of a heterochromatic supernumerary segment in the grasshopper Eyprepocnemis plorans.

Several components of fitness were analysed in relation to the presence of a supernumerary chromosome segment (SCS) in two natural populations of the grasshopper Eyprepocnemis plorans, including clutch size, egg fertility, egg and embryo productivity and survivability from embryo to adult, and SCS transmission through males. The results have shown the absence of a significant relationship between SCS presence and these fitness components, with the single exception of egg fertility which decreases significantly in SCS females with mating shortage. This fertility decrease is thus expected to be relevant for the population dynamics of the SCS only in low-density populations, those in which it is difficult for females to find a male to copulate with before each egg-batch is ready to be laid. The analysis of the SCS transmission through males showed no significant differences between expected and observed SCS frequencies. The SCS polymorphism seems to be at a status close to neutrality in respect to fitness, but its slight disadvantage in transmission through females carrying B chromosomes predicts that the polymorphism should tend to disappear, unless SCS recurrent amplification, or another undiscovered force, counteracts this tendency.

Analysis of Variance↗

Levels of HBV-DNA and HBsAg after acute liver allograft rejection treatment by corticoids and OKT3.

The aim of this work was to analyze whether the treatment of acute rejection of orthotopic liver transplants (OLT), either with corticoids or OKT3, has any effect on the levels of hepatitis B virus (HBV)-DNA and HBsAg in individuals which were originally affected by cirrhosis or fulminant hepatic failure as a result of B virus. We have found that HBV-DNA is present in macrophages, B cells and both CD4+ and CD8+ T cells after OLT in all cases studied. Interestingly, the levels of HBV-DNA and HBsAg in the serum analyzed were increased extremely rapidly in the patients treated with OKT3 in an acute rejection episode. However, the serum levels of HBV-DNA and HBsAg found were lower when the patients were treated with steroids, and were not found in non-treated patients. As the serum levels of HBV-DNA increase, the process of liver reinfection could be accelerated; therefore, these results may help to understand how OKT3 and corticoids immunosuppressive therapy may accelerate the reinfection of OLT by HBV. In conclusion, our results suggest that special care must be taken in the use of OKT3 in the treatment of acute liver rejection episodes in chronic or fulminant HBV transplanted patients.

Acute Disease↗

Hydroxyurea inhibits the transactivation of the HIV-long-terminal repeat (LTR) promoter.

HIV-1 gene expression is regulated by the promoter/enhancer located within the U3 region of the proviral 5' LTR that contains multiple potential cis-acting regulatory sites. Here we describe that the inhibitor of the cellular ribonucleoside reductase, hydroxyurea (HU), inhibited phorbol myristate acetate- or tumour necrosis factor-alpha-induced HIV-1-LTR transactivation in both lymphoid and non-lymphoid cells in a dose-dependent manner within the first 6 h of treatment, with a 50% inhibitory concentration of 0.5 mM. This inhibition was found to be specific for the HIV-1-LTR since transactivation of either an AP-1-dependent promoter or the CD69 gene promoter was not affected by the presence of HU. Moreover, gel-shift assays in 5.1 cells showed that HU prevented the binding of the NF-kappaB to the kappaB sites located in the HIV-1-LTR region, but it did not affect the binding of both the AP-1 and the Sp-1 transcription factors. By Western blots and cell cycle analyses we detected that HU induced a rapid dephosphorylation of the pRB, the product of the retinoblastoma tumour suppressor gene, and the cell cycle arrest was evident after 24 h of treatment. Thus, HU inhibits HIV-1 promoter activity by a novel pathway that implies an inhibition of the NF-kappaB binding to the LTR promoter. The present study suggests that HU may be useful as a potential therapeutic approach for inhibition of HIV-1 replication through different pathways.

Antigens, CD↗

Treatment of proximal hypospadias with a tubularized island flap urethroplasty and the onlay technique: a comparative study.

BACKGROUND/PURPOSE: The onlay island flap urethroplasty was first described in the repair of mid and distal penile hypospadias. Since then, this technique has been increasingly used in more severe cases of hypospadias, because of the complications of tubularized flaps, mainly megaurethra and proximal anastomotic strictures. The aim of this study was to compare the morbidity of these 2 techniques. METHODS: Between April 1994 and December 1998, 80 patients underwent surgical treatment for hypospadias. A tubularized island flap (Ducketttechnique) was performed in 42 cases, and the onlay island flap technique was used in 38 patients. The authors retrospectively compared the complication rate and type of these 2 procedures. RESULTS: Altogether, fistula was the most frequent complication without any significant difference between the 2 groups (21.4% for Duckett technique and 18.4% for onlay repair; P > .05). However, the anastomotic stricture was much more common in the tubularized flap group (7.14% v 2.63%; P < .05). Moreover, a megaurethra was found only in the Duckett technique group (4.7%). There was no case of chordee recurrence, but 6 patients (15.7%) treated with the onlay technique required urethrolysis including dissection of the chord behind the urethral plate, and in the other 3 patients of the same group (7.9%), a dorsal Nesbit plication also was necessary. In all these cases, the urethroplasty included an island cutaneous flap to provide ventral coverage to the neourethra. CONCLUSIONS: The authors conclude that both techniques present similar complications. However, proximal strictures and megaurethra are more common after the Duckett technique. This procedure is of choice in patients with scrotal hypospadias. Conversely, the onlay repair should be completed with other procedures (urethrolysis, dorsal Nesbit plication) to obtain good results in patients with severe degree of chordee.

Child, Preschool↗

Lack of hemoglobin response to iron supplementation in anemic mexican preschoolers with multiple micronutrient deficiencies.

BACKGROUND: In developing countries, incomplete resolution of anemia with iron supplementation is often attributed to poor compliance or inadequate duration of supplementation, but it could result from deficiencies of other micronutrients. OBJECTIVE: Our objective was to assess children's hematologic response to supervised, long-term iron supplementation and the relation of this response to other micronutrient deficiencies, anthropometry, morbidity, and usual dietary intake. DESIGN: Rural Mexican children aged 18-36 mo (n = 219) were supplemented for 12 mo with either 20 mg Fe, 20 mg Zn, both iron and zinc, or placebo. Children were categorized as iron-unsupplemented (IUS; n = 109) or iron supplemented (IS; n = 108). Hemoglobin, hematocrit, mean corpuscular volume, mean cell hemoglobin, plasma concentrations of micronutrients that can affect hematopoiesis, anthropometry, and diet were assessed at 0, 6, and 12 mo; morbidity was assessed biweekly. RESULTS: At baseline, 70% of children had low hemoglobin (</=115 g/L), 60% had low hematocrit, 48% were ferritin deficient, 10% had deficient and 33% had low plasma vitamin B-12 concentrations, 29% had deficient vitamin A concentrations, and 70% had deficient vitamin E concentrations. Iron supplementation increased ferritin from 11 +/- 14 microg/L at baseline to 31 +/- 18 microg/L after 6 mo (P < 0.001) and 41 +/- 17 microg/L after 12 mo. However, anemia persisted in 30% and 31% of supplemented children at 6 and 12 mo, respectively, and was not significantly different between the IUS and IS groups at 12 mo. Initial plasma vitamin B-12, height-for-age, and dietary quality predicted the hematopoietic response to iron. CONCLUSION: Lack of hemoglobin response to iron was associated with indicators of chronic undernutrition and multiple micronutrient deficiencies.

Anemia↗