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A Acevedo

Publications and source records attributed to A Acevedo.

At least 37 records · Page 2Linked to original sources
PubMed2000

Levels of interleukin-1 beta, -8, and -10 and RANTES in gingival crevicular fluid and cell populations in adult periodontitis patients and the effect of periodontal treatment.

BACKGROUND: Various cytokines have been identified at sites of chronic inflammation such as periodontitis. Cytokines are synthesized in response to bacteria and their products, inducing and maintaining an inflammatory response in the periodontium. The purpose of the present study was to investigate the involvement of interleukin-1 beta (IL-1 beta), IL-8, and IL-10 and RANTES (regulated on activation, normally T cell expressed and secreted) and the cell populations associated with the immune response in destructive periodontitis, as well as the effect of periodontal therapy on cytokine levels in gingival crevicular fluid (GCF). METHODS: Data were obtained from 12 patients with moderate to advanced periodontitis and 6 healthy controls. Patients presenting at least 2 sites with > or =2 mm clinical attachment loss were included in the destructive periodontitis group. After monitoring for 4 months, only 6 patients showed destructive periodontitis and GCF samples and soft tissues biopsies were collected from these patients. GCF samples and biopsies were collected both from active (12 CGF samples and 6 biopsies) and inactive (12 CGF samples and 6 biopsies) sites. The comparison with healthy controls was carried out by collecting GCF samples from 6 healthy volunteers (12 samples) and biopsies during the surgical removal of wisdom teeth. In periodontal patients, clinical data and GCF samples were obtained prior to periodontal treatment (72 samples) and 2 months after periodontal therapy (72 samples). GCF was collected using a paper strip; eluted and enzyme-linked immunoabsorbent assays (ELISA) were performed to determine cytokine levels. The inflammatory infiltrate was analyzed by immunohistochemistry of gingival biopsy samples with monoclonal antibodies against CD3, CD8, CD4, CD11c, and CD19 antigens. RESULTS: Cellular components of the inflammatory infiltrate include B and T lymphocytes and monocyte/macrophages. Active sites contained a higher number of B lymphocytes and macrophages. IL-8 and IL-1 beta and RANTES in GCF were detected in the majority of sites from periodontal patients (100%, 94% and 87%, respectively); IL-10 was found in only 43%. IL-8 was the only cytokine detected in the GCF (75%) of the control group. Moreover, IL-1 beta levels were significantly higher in active sites versus inactive sites (P <0.05). IL-8 and IL-10 and RANTES were increased in active sites; however, differences were not significant (P>0.05). A positive correlation between the IL-8 and RANTES (r = 0.677, P<0.05) was observed in periodontitis patients. Periodontal therapy reduced the total amount of IL-1 beta, IL-8, and IL-10 and RANTES. Data showed a weak correlation between the clinical parameters and the total amount of cytokines in periodontitis. CONCLUSIONS: These data suggest that the amount of crevicular IL-1 beta, IL-8, and IL-10 and RANTES is associated with periodontal status. Removal of the bacterial plaque reduces the antigenic stimuli and consequently could modulate the chemokines present in GCF. We propose that the dynamic interactions between cytokines, their production rates, and their quantity could represent factors controlling the induction, perpetuation, and collapse of the cytokine network present in the periodontal disease.

Adult↗
PubMed2000

Epstein-Barr virus-latent membrane protein 1 expression has a favorable influence in the outcome of patients with Hodgkin's Disease treated with chemotherapy.

The effect of molecular factors in the outcome of Hodgkin's Disease (HD) is being currently studied. In a previous series of HD, including patients treated only with radiotherapy and patients treated with chemotherapy (with or without radiotherapy), we found that a high proliferation index had an adverse influence in overall survival (OS) and in the achievement of a complete remission (CR). Loss of Rb expression also had an adverse prognostic influence in achievement of CR. On the other hand LMP1-EBV expression had a favorable influence for OS. The expression of other molecular factors, p53, bcl2 and CD15 did not show prognostic influence. In the present paper we have studied the effect of these molecular variables in 110 patients, of the previous series who had been treated with chemotherapy. A retrospective study was performed in these 110 patients with HD treated with chemotherapy (ABVD or variants, 62%, or regimes not containing adriamycin, 38%) with or without adjutant radiotherapy, collected at the 11 centers belonging to the Spanish Collaborative Group for the Study of Hodgkin's Disease. The prognostic value of clinical variables and the expression of p53, bcl2, CD15, Rb, LMP 1-EBV and proliferative fraction demonstrated with sensitive immunohistochemical methods were studied. Cox's multivariate analysis was performed to assess their influence in failure-free survival (FFS) and OS. A multivariate logistic regression analysis was performed for studying the effect of the variables in the achievement of a CR. Of the clinical variables, only advanced stage (III/IV) had a significant independent adverse influence in FFS, in OS and in the achievement of CR and advanced age in OS. Of the molecular variables, LMP1-EBV had an independent and strong favorable influence in FFS, in OS and in the achievement of CR. Rb expression had a modest favorable influence in CR. The rest of the molecular variables had no independent influence on the outcome of the disease. In conclusion these results confirm the favorable prognostic value of LMP1-EBV expression in the subset of patients with HD treated with chemotherapy.

Analysis of Variance↗
PubMed2000

[Esophageal motility disorders in patients with esophageal reflux disease without pathologic reflux by 24 h esophageal pH monitoring].

BACKGROUND: In a high proportion of patients with symptomatic gastroesophageal reflux disease, 24 h esophageal pH monitoring is normal. AIM: To study esophageal motility in patients with symptomatic gastroesophageal reflux disease and normal 24 h esophageal pH monitoring. PATIENTS AND METHODS: Fourteen patients (12 women, aged 28 to 74 years old) with esophageal reflux disease and normal 24 pH monitoring and 14 asymptomatic controls (8 women, aged 19 to 69 years old), were studied. Symptoms were evaluated using an analog scale and all subjects underwent a barium meal, upper gastrointestinal endoscopy and a standard esophageal manometry. RESULTS: Lower esophageal sphincter was normal in 11 patients, hypotonic in one and displaced to the thorax in two. Esophageal wave amplitude was lower in patients than in asymptomatic controls (10 to 50 and 13 to 70 mm Hg respectively). The proportion of hypotonic waves was Grade I and II in seven patients, Grade III in three and grade IV in four cases. Four patients had localized aperistalsis (that can be considered normal) and four had more severe forms of aperistalsis, along with severe hypotonia. CONCLUSIONS: Patients with gastroesophageal reflux disease without alterations in 24 h pH monitoring, have alterations in esophageal motility.

Adult↗
PubMed1998

[Outcome of 70 patients diagnosed with Hodgkin's disease after first-line and salvage treatment: experience at one center].

BACKGROUND: Retrospective analysis of 70 patients with Hodgkin's disease (HD) and treated consecutively in our center between 1979 and 1993. PATIENTS AND METHODS: All ganglionar biopsies were reviewed and finally 60 patients were selected: 43 males and 17 females with a median age of 39 years (12-79) and the following features: 55% III-IV stages, 25% extranodal involvement, 32% bulky mediastinum and 57% B-symptoms. Scheme of treatment: Only radiotherapy in 9 patients with localized stages and no adverse factors; only chemotherapy in 25 with advanced stages and combined therapy in 15 with localized stages and any adverse factor and in 7 with advanced stage and bulky disease. Chemotherapy was mainly based on MOPP until 1987 and MOPP/ABVD afterwards. Only four patients did not follow this scheme: 2 due to progression, 1 due to toxicity and 1 due to medical decision. RESULTS: Fifty patients achieved complete remission (CR), 2 partial and 8 minimal response or progression under therapy. Eleven patients have died: 6 due to HD, 4 of second neoplasias and 1 of an opportunistic infection. With a median follow-up for surviving patients of 4.8 years (1-2), the estimated overall survival at 8 years is 67.7% (SD 9%), tumor mortality 82.6% (SD 7%) and progression free survival 66.7% (SD 7%). Disease free survival for CR patients is 78.4% (SD 9%). Response to treatment was the only factor significantly associated with survival (p = 0.0001). The estimated survival for CR patients who relapsed is 92.3% versus 28% for those who did not obtain a CR (p = 0.0001). CONCLUSION: In our experience, first line therapy adjusted to clinical features at diagnosis has good results. Response to treatment has been the determinant factor for survival, mostly because salvage treatments, including high-dose chemotherapy approaches, have been of little effectiveness.

Adolescent↗
PubMed1997

The role of ferredoxin-NADP+ reductase in the concerted cell defense against oxidative damage -- studies using Escherichia coli mutants and cloned plant genes.

Ferredoxin-NADP+ reductases (FNR) participate in cellular defense against oxidative damage. Escherichia coli mutants deficient in FNR are abnormally sensitive to methyl viologen and hydrogen peroxide. Tolerance to these oxidants was regained by expression of plant FNR, superoxide dismutase, or catalase genes in the mutant cells. FNR contribution to the concerted defense against viologen toxicity under redox-cycling conditions was similar to that of the two major E. coli superoxide dismutases together, as judged by the phenotypes displayed by relevant mutant strains. However, FNR expression in sodA sodB strains failed to increase their tolerance to viologens, indicating that the FNR target is not the superoxide radical. Sensitivity of FNR-deficient cells to oxidants is related to extensive DNA damage. Incubation of the mutant bacteria with iron chelators or hydroxyl radical scavengers provided significant protection against viologens or peroxide, suggesting that oxidative injury in FNR-deficient cells was mediated by intracellular iron through the formation of hydroxyl radicals in situ. The NADP(H)-dependent activities of the reductase were necessary and sufficient for detoxification, without participation of either ferredoxin or flavodoxin in the process. Possible mechanisms by which FNR may exert its protective role are discussed.

Bacterial Proteins↗
PubMed1997

Adverse clinical outcome in Hodgkin's disease is associated with loss of retinoblastoma protein expression, high Ki67 proliferation index, and absence of Epstein-Barr virus-latent membrane protein 1 expression.

Previous studies have shown that in non-Hodgkin's lymphomas and others neoplasms, tumoral progression, treatment response, and outcome are related to the expression of different oncogenic and tumor suppressor proteins. This study aimed to determine the prognostic significance of the expression of p53, bcl2, retinoblastoma protein (Rb), Ki67, CD15, and latent membrane protein 1-Epstein-Barr Virus (LMP1-EBV) proteins in Hodgkin's disease. A retrospective study was performed on 140 patients collected at the 11 participating centers belonging to the Spanish Collaborative Group for the Study of Hodgkin's Disease. A highly sensitive immunohistochemical method with previous microwave-induced antigen retrieval technique was used for the demonstration of the above-mentioned proteins. A Cox's multivariate analysis was performed to evaluate the impact of the variables in the overall survival, together with a logistic regression model for the achievement of complete remission. Univariate statistical analysis confirmed the prognostic significance of the alredy known clinical parameters: stage, age over 60 years, and B symptoms. High proliferation index (Ki67) and loss of Rb expression were also found to be adverse prognostic factors influencing respectively lower overall survival and failure to achieve complete remission. Multivariate analysis confirmed the independent significance of these two parameters and additionally identifies LMP1-EBV expression as a favorable prognostic marker, in relation with overall survival. Histopathological type, p53, bcl2, and CD15 expression lack significant influence on the outcome of this series. The progression of the disease or the response to treatment in HD patients is the consequence of the interrelationship of different factors, among which LMP1 expression, loss of Rb, and high growth fraction seems to play a more relevant role.

Adolescent↗
PubMed1997

Magnetic resonance imaging features of chloroma of the shoulder.

A patient with a history of essential thrombocytosis presented with diffuse skeletal pain and restricted motion of the left shoulder. Magnetic resonance imaging (MRI) of the left glenohumeral joint showed a soft tissue mass that displaced the rotator cuff. Biopsy of the mass revealed chloroma. MRI is the method that best characterizes this lesion.

Aged↗
PubMed1997

Molecular analysis of the IgH gene in 212 cases of Hodgkin's disease: correlation of IgH clonality with the histologic and the immunocytochemical features.

The aims of this study are to evaluate the frequency of clonal immunoglobulin heavy chain gene rearrangements in paraffin-embedded samples of Hodgkin's disease (HD) with use of the polymerase chain reaction method and to correlate the molecular findings with the histologic and immunocytochemical features. DNA extracts from paraffin-embedded sections from 212 HD samples were used for amplification of the IgH gene by use of framework 2 and framework 3 region primers. Immunohistochemical studies were performed on paraffin sections by use of monoclonal antibodies for CD20 and latent membrane protein-1 and polyclonal antibody for CD3. With use of both primer combinations, monoclonality was detected in 18.7% of lymphocyte-predominant HD cases and in 32.2% of classical HD cases. These results suggest that immunoglobulin heavy chain gene clonal rearrangements are relatively frequent in classical HD. In addition, the statistical analyses of the genotypic and immunocytochemical data revealed that the detection of B-cell populations is significantly associated with the expression of CD20 on HRS cells. There was, however, no correlation between the histologic subtype, the percentage of HRS cells, the presence of latent membrane protein-1 expression, and the molecular analysis results.

Antigens, CD20↗
PubMed1996

Pathological, immunological, and molecular features of Hodgkin's disease associated with HIV infection. Comparison with ordinary hodgkin's disease.

The aim of the present study was to analyze in a series of 24 HIV-positive Hodgkin's disease (HD) patients the morphological and immunological features, the presence of rearrangements in the immunoglobulin heavy chain (IgH) gene, expression of the Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1), and the existence of deletions in the intracytoplasmic domain of the LMP-1 gene. The results obtained were compared with those from a parallel series of 56 patients with ordinary HD. Briefly, comparison of the two series showed a predominance of unfavorable histological subtypes in HIV-positive HD patients. The mixed cellularity subtype was more frequent in HIV-positive than in HIV-negative HD patients: the difference in percentage was statistically significant (p = 0.04). Neoplastic cell-rich cases were significantly more frequent (p = 0.40) in HIV patients (59%) than in ordinary HD patients (34%). In 25% of HIV-infected and in 14% of ordinary HD patients, the neoplastic cells were CD20+, a difference that was not statistically representative. Clonal IgH rearrangements were detected in 33% of HIV-infected patients and in 23% of ordinary HD patients, a nonsignificant difference. LMP-1 expression was detected in 100% of HIV-positive patients and in 57% of ordinary HD patients (p = 0.004). A 30-base-pair deletion in the carboxy-terminal domain of the LMP-1 gene was found in 16 of 18 HIV-infected patients (89%), whereas it was identified in only 8 of 25 ordinary HD patients (32%) (p = 0.008). In conclusion, HD in HIV-infected patients as compared with HD in HIV-negative individuals is associated with morphological features of aggressivity, with a higher frequency of neoplastic cells, and with constant LMP-1 expression. The fact that LMP-1 is expressed in all HIV-infected patients suggests that EBV plays an etiological role in the pathogenesis of HIV-associated HD. Furthermore, the presence of EBV strains carrying deletions near the 3' end of the LMP-1 gene in the majority of cases may be related with the morphological and clinical aggressivity of HD in immunocompromised patients.

Adult↗
PubMed1996

Gelatinous degeneration presenting as a preleukaemic syndrome.

Gelatinous degeneration of marrow is a rare histological disorder associated with chronic debilitating diseases, such as anorexia nervosa, AIDS and postchemotherapy aplasia. Solid tumours have been associated with this condition but it has been reported in only two patients with leukaemia. In these cases leukaemia and gelatinous degeneration were diagnosed simultaneously. In the case reported here, a 48 year old man, gelatinous degeneration was the only histological finding observed more than two years before the diagnosis of acute myelogenous leukaemia with monosomy 7. The significance of hyaluronic acid deposition remains uncertain. Two hypotheses have been put forward: (1) that gelatinous degeneration occurs during tissue repair; and (2) that gelatinous degeneration inhibits haemopoiesis by altering the microenvironment of the bone marrow. In the case reported here, the presence of monosomy 7 suggests that myelodysplasia was the underlying disorder which finally evolved into acute leukaemia.

Bone Marrow↗
PubMed1995

Expression of vascular adhesion molecules on human endothelia in autoimmune thyroid disorders.

Cellular activation and expression of certain adhesion molecules within vascular endothelium is a critical event in leucocyte recruitment and emigration. A wide array of different adhesion receptors has been identified to mediate the interaction between endothelial cells (EC) and leucocyte subpopulations. In this study, the tissue expression of E-selectin, P-selectin, CD31, and endoglin endothelial cell adhesion molecules was studied on thyroid tissue from patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT). We found an up-regulated expression of E-selectin in EC in GD and HT thyroids, specifically in those areas more severely inflamed, with no reactivity in control thyroids. P-selectin was basally expressed in postcapillary venules in control glands, with an increased expression in HT and GD glands. On the other hand, increased CD31 expression was found on perifollicular, small and large venule EC from GD and HT glands, that correlated with the severity of mononuclear infiltration. In addition, CD31 expression was observed in some intrathyroidal macrophages and T cells in close proximity to CD31+ EC. Furthermore, a markedly enhanced expression of endoglin, a transforming growth factor-beta binding protein, was mainly located on perifollicular EC and EC from small venules as well as in adjacent macrophages from GD and HT thyroid glands. This enhanced expression of E- and P-selectins, CD31 and endoglin by thyroid EC in GD and HT may reflect their ability to regulate leucocyte trafficking and activation.

Antigens, CD↗
PubMed1994

[Castleman's disease: description and comments on 3 cases].

Three representative cases of the clinical heterogeneity of Castleman's disease are presented: one localized form with hialine vascular histology (HV) and 2 multicentric forms corresponding to the plasmocellular variety (PC). The asymptomatic patient with HV was treated with surgical resection of one tumor. The 2 patients with the symptomatic PC variant were characterized by the different clinical presentation receiving polychemotherapy and steroids, respectively with good response. The literature is reviewed and the pathogenetic, clinical and therapeutic aspects of the disease, which remains difficult to define as a sole entity, are discussed.

Adult↗
PubMed1994

Human CD45RC specificity. A novel marker for T cells at different maturation and activation stages.

The different isoforms of CD45 seem to play an important role in thymocyte maturation and T cell activation and function. To investigate the particular contribution of CD45-exon C (exon 6) to human T cell development, we first investigated the expression of the CD45-exon C isoforms on different human lymphoid cell populations. A wide panel of mAbs against the different isoforms of CD45 was generated by immunizing mice with purified human CD45. Two of these mAbs (RP1/12 and RP2/19) selectively recognized mouse 300-19 pre-B cells that had been transfected with CD45 cDNA that contained exon C, suggesting that epitopes recognized by these mAbs are dependent on the expression of exon C. Immunofluorescence analysis of PBLs showed that CD45RC is expressed at high levels on B, NK, and CD8+ T cells, although a subset of CD4+ T cells was found to be negative. Activation of PBMCs and purified NK cells resulted in down-regulation of CD45RC, which took place in a coordinate manner involving both down-regulation of the expression of CD45RA and CD45RB and up-regulation of CD45R0. Two-color immunofluorescence analyses showed that thymocytes expressing CD45RC were CD1-to lo, CD3hi and HLA class Ihi, typical markers of mature thymocytes. Accordingly, immunohistochemical analysis of a normal thymus showed that whereas the anti-CD45RA mAb stained only a subset of medullary thymocytes, the anti-CD45RC mAb stained the majority of medullary thymocytes. Thymocytes that bear CD45RA also express CD45RC, but do not express CD45RO; a subset of CD45 RA- RO+ thymocytes was also detected. Immunoprecipitation of CD45 molecules from both PBMC and thymocyte cell lysates with mAbs against the different specificities of this molecule revealed that the RC determinants are found on CD45 polypeptides of 220 and 205 kDa that also bear RB or both RB and RA determinants, respectively. Together these results support both the existence of a tight regulation of the expression of CD45 specificities during lymphocyte activation and thymocyte maturation and also that CD45RC is selectively expressed by mature medullary thymocytes during T cell ontogeny.

Alternative Splicing↗
PubMed1994

Adhesion molecules from the LFA-1/ICAM-1,3 and VLA-4/VCAM-1 pathways on T lymphocytes and vascular endothelium in Graves' and Hashimoto's thyroid glands.

Lymphocytic infiltration of the thyroid gland in autoimmune thyroid disorders requires, as a first step, their attachment to endothelial cells (EC) and subsequently, their interaction with thyrocytes and extracellular matrix proteins. A number of different ligand molecules have been identified to mediate the interaction between EC and leukocyte subpopulations. In this study, we examined by flow cytometry and immunohistochemical techniques, the expression of integrin receptors and their counter-receptors by infiltrating lymphocytes and vascular endothelium in thyroid glands from patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT). A high proportion of GD intrathyroidal T lymphocytes expressed the CD69 and gp95/85 (Ea2) activation antigens as well as an increased number of LFA-alpha L, VLA-alpha 1, -alpha 4, -alpha 5, and beta 1 integrin receptors, as compared with peripheral blood T lymphocytes from the same patients. The expression of intercellular adhesion molecule (ICAM)-1 was increased in EC from GD and HT thyroids. In addition, an up-regulated de novo expression of vascular cell adhesion molecule (VCAM)-1 was found in EC in GD and HT thyroids, with no reactivity in control thyroids. Dendritic cells in thyroid lymphoid follicles were also positive for ICAM-1 and VCAM-1. In addition, most of intrathyroidal mononuclear cells expressed the ICAM-3 adhesion molecule. This enhanced expression of ICAM-1 and VCAM-1 by thyroid EC in GD and HT may reflect their ability to regulate leukocyte trafficking and activation by means of the expression of specific ligand molecules. Our data suggest that both the LFA-1/ICAM-1, ICAM-3 and VLA-4/VCAM-1 pathways could play a relevant role in localizing and perpetuating the autoimmune response in the thyroid gland in autoimmune thyroid disorders.

Antigens, CD↗
PubMed1994

Collection, separation and cryopreservation of umbilical cord blood for use in transplantation.

Bone marrow transplantation (BMT) is limited by the paucity of HLA-matched donors and the frequent occurrence of graft-versus-host disease (GVHD). Recent clinical reports have implied that the use of umbilical cord blood (UCB) may alleviate some of the problems associated with BMT. Banks of frozen UCB could make the problem of finding suitable stem cell donors easier and stem cell grafts would be more readily available. However, definitive experiments are needed to develop optimal methods for collection, separation and storage of cryopreserved UCB for extended periods of time. We have found that several simple techniques may be utilized to collect large volumes of UCB (up to 220 ml). Also, modification of a common density gradient separation method permits recovery of large quantities of UCB mononuclear cells. Finally, we have examined the effects of prolonged frozen storage on the ability to recover viable and functional UCB, particularly stem/progenitor cells. It was observed that storage of UCB in liquid nitrogen for as long as 7 years had minimal effects on cell viability, cellular composition of UCB and progenitor/stem cell capacity. Thus, the establishment of UCB banks for use in transplantation appears to be a feasible approach.

Blood Banks↗
PubMed1993

Analysis of the hairless mouse as a model for the effects of aging on the immune system.

Studies into the effects of aging on the immune system are hampered by the lack of a suitable animal model that is readily available and cost efficient. The mutant mouse, hairless (hr/hr genotype), has been shown to undergo an accelerated thymic involution with accompanying immunodeficiency. Thus, this strain of mouse has been proposed as a model for studying the interactions of aging and immune function. We have investigated the effects of homozygous hr gene expression over time on the immune function of these mice. It was observed that homozygous hr gene expression had minimal effects on peripheral lymphocyte subset compositions but did appear to result in changes in thymic differentiation. Further, hr/hr mice displayed decreased proliferative responses to IL2 and mitogen stimulation, although cytotoxic responses (both NK and T cell mediated) appeared normal. These defects appear to be attributable to T helper cell dysfunction. Each of the changes found in hr/hr mice were distinct from those seen with age-matched control mice. Thus, the hr/hr inbred strain of mouse does not appear to be a suitable model for use in analyzing the effects of aging on the immune system.

Aging↗