Biomedical subjects

R Castejón

Publications and source records attributed to R Castejón.

13 recordsLinked to original sources

PubMed2003

Production of intracellular IL-2, TNF-alpha, and IFN-gamma by T cells in B-CLL.

BACKGROUND: Recent evidence indicates that the slowly expanding population of CD5(+) B cells that characterizes B-cell chronic lymphocytic leukemia (B-CLL) could be related to defects in the response to cytokine produced by T cells that regulate apoptosis. We studied the intracellular expressions of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) in T-helper 1 cells (Th1 response) of B-CLL. METHODS: Peripheral blood mononuclear cells from 21 healthy individuals and purified T cells from 21 early-stage and 15 late-stage B-CLL patients were activated with phorbol myristate acetate and ionomycin. The Th1 cytoplasmic cytokines were evaluated in CD4(+) and CD8(+) T cells by flow cytometry. RESULTS: The percentages of CD4(+) and CD8(+) T cells positive for IL-2 were significantly lower in B-CLL patients than in healthy individuals (P = 0.030 and 0.049, respectively). No significant differences in TNF-alpha or IFN-gamma intracellular expressions were found between patients and healthy individuals. TNF-alpha- and IFN-gamma-expressing CD8 T cells were disease stage dependent, being significantly higher in late-stage patients (P < 0.001 for both cytokines). CONCLUSIONS: Our present observations suggested that Th1 cytokines may be of major importance in the pathogenesis of B-CLL.

Adult↗

PubMed2002

Flow-cytometric assessment of lymphocyte cytokine production in tuberculosis.

We assessed by flow-cytometry the Th1/Th2 profiles in peripheral blood lymphocytes (PBL) from patients with active tuberculosis (TB), before and after antituberculous therapy, and from healthy tuberculin-positive and -negative reactors. PBL from patients showed a reduced potential for Th1-cytokine (notably IFN- gamma) production after culture with a policlonal stimulus. When these PBL from patients were cultured with a M. tuberculosis (MTB)-specific antigen such as PPD (10 microg/ml), there was no detectable production of Th1 cytokines. Only the Th2 cytokine IL10 was detected in PBL from patients but not from controls. However, at the site of the tuberculosis disease, T lymphocytes from bronchoalveolar lavage, after culture with PPD, produced IFN- gamma. After completion of tuberculosis therapy, PBL did not produce IL10. These data indicate that the immunosuppression observed in PBL during active tuberculosis infection may be related to IL10 production, and to the compartmentalization of the antigen-Th1 response to sites of active MTB infection.

Adult↗

PubMed2002

[Study of pulmonary lesions with (99m)Tc-Tetrafosmin and chest spect. Determination of uptake related factors, diagnostic value and prognosis].

One hundred fifteen patients with 119 pulmonary lesions in which malignancy was suspected underwent a SPECT study with 99mTc-Tetrofosmin (TTF) to assess the possible factors involved in the uptake of the radiopharmaceutical. The TTF uptake rate in the lung tumor with respect to that of healthy tissue (TTF index) was evaluated in terms of: benignity and malignancy, histological type, stage, cell differentiation, size, necrosis, survival and the influence of P-glycoprotein (Pgp), detected by immunohistochemistry, on the TTF uptake. The mean TTF index in the 18 benign lesions studied was 1.01 0.05, while that of the 101 malignant lesions was 1.59 0.45 (p < 0.001), with a positive predictive value of 97.7% and a negative predictive value of 50%. The comparison of the histological types, degree of cell differentiation, necrosis and stage revealed no statistically significant differences. With respect to size, those tumors measuring > 3 cm showed greater uptake than smaller lesions. In patients with non-small cell lung cancer, a positive relationship was observed between the TTF index and survival, a circumstance that did not occur in patients with small cell lung cancer. In the cases in which the presence of Pgp was assessed, there was an inverse relationship between the TTF ratio and Pgp expression. In conclusion, thoracic SPECT with 99mTc-TTF has a high positive predictive value for the presence of lung cancer, although a negative study does not rule out the existence of the disease. The reason for this is the inverse relationship between 99mTc-TTF uptake and the density of Pgp expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

Aminoguanidine reduces apoptosis of circulating V Beta 8.2 T lymphocytes in Lewis rats with actively induced experimental autoimmune encephalomyelitis. Association with persistent inflammation of the central nervous system and lack of recovery.

Aminoguanidine therapy delayed the onset of actively induced EAE in Lewis rats, but recovery was impaired in most animals. In the central nervous system this was correlated with persistent inflammation and production of proinflammatory cytokines. In the periphery of aminoguanidine-treated animals, T lymphocytes showed increased proliferation against myelin basic protein, and the percentage of Vbeta 8.2(+) T lymphocytes undergoing early apoptosis was markedly decreased, although it was unchanged in Vbeta 8.2(+) T cells isolated from the spinal cord. These results suggest that the prolonged survival of circulating encephalitogenic cells achieved by aminoguanidine would favor a longer lasting entry of these cells into the nervous system resulting in persistent inflammation and lack of recovery.

Animals↗

PubMed1999

Modulation of apoptosis by cytokines in B-cell chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the slow and progressive accumulation of monoclonal apparently mature, CD5(+) B lymphocytes. The majority of circulating cells appear to be nondividing, and it has been suggested that a prolonged life span is mainly responsible for the accumulation of the leukemic cells. However, spontaneous programmed cell death by apoptosis occurs when B chronic lymphocytic leukemia cells are cultured in vitro. This may be because of the lack of an unidentified essential cytokine present in vivo. Thus, we investigate interleukin-2 (IL-2), IL-4, IL-6 and IL-10 in vitro effects on apoptosis of B cells from 32 previously untreated patients with B-CLL in initial clinical stages. B cells were isolated from peripheral blood, and apoptosis was measured in these cells immediately after isolation and following incubation in vitro, without and with the different cytokines, for 24 and 48 h. Distribution of cellular DNA content and quantitative analysis of apoptosis were determined by standard propidium iodide staining and flow cytometry. Spontaneous apoptosis occurred in B-CLL cells incubated in vitro in the absence of cytokines. Our results indicate that both IL-2 and IL-4, but not IL-6, inhibit in vitro apoptosis in a large percentage of B-CLL patients. IL-10 increases in vitro apoptotic cell number in stage 0 patients, but not in stage I and II. These data support the hypothesis that IL-2 or IL-4, may be cell survival factors in vivo and that IL-10 might be a candidate for immune therapy of early B-CLL.

Adult↗

PubMed1999

Characterization of adrenal medullary chromaffin cells by flow cytometry.

BACKGROUND: Adrenomedullary chromaffin cells are neural crest derivatives widely used as a model system to study neurosecretory mechanisms. Morphological, immunohistochemical, and functional data indicate that chromaffin cells are heterogeneous and support the distinction between adrenaline (A)- and noradrenaline (NA)-producing and secreting cells. The aim of this study was to characterize by flow cytometry the two main chromaffin cell subtypes in suspensions of cultured bovine chromaffin cells. METHODS: An indirect immunofluorescence method was used for the specific labeling of two intracellular enzymes, dopamine beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT), involved in the synthesis of NA and A, respectively. Flow cytometry analysis of fluorescence labeling was performed in two chromaffin cell fractions differentially enriched in A-containing cells by centrifugation through density gradients. PNMT and DBH-related fluorescence was also correlated with the A and NA content of the cells assayed by HPLC measurements. RESULTS: No significant differences were found in forward-side scatter plots between the two cell fractions (A-enriched cells and mixed cells); however, the degree of labeling of the enzymes and the corresponding PNMT/DBH-related fluorescence ratio was significantly greater in the A-enriched cell fraction. The existence of changes in DBH and PNMT content of chromaffin cells over time (1 week) in culture was also examined. No significant variation in enzyme related fluorescence values was detected in any of the two cell fractions, and this result correlated well with HPLC determinations of the catecholamine content (A and NA) of the cells. CONCLUSIONS: Flow cytometry appears to be a useful technique to characterize chromaffin cell subtypes and to follow their phenotypic changes in response to growth factors.

Adrenal Medulla↗

PubMed1999

[Preliminary study by flow cytometry of the cell cycle and DNA quantification in cytokeratin-positive cells in tumors of the head and neck].

DNA ploidy and cell-cycle distribution were determined by flow cytometry in fresh tumor tissue of 27 epithelial head and neck carcinomas. Epithelial cells were labeled with a fluorescein-isothiocyanate-conjugated cytokeratin antibody to study the possible influence of contaminating stromal and inflammatory cells on the results of cell-cycle analysis of tumor cells. The patient sample included 26 men and 1 women with a mean age of 60 years. Without cytokeratin gating, 11/27 tumors (40.74%) were aneuploid. After selecting the cytokeratin population, 10 more aneuploid tumors were found that had not been detected when considering the total population. Therefore, aneuploid tumors increased from 40.74% to 77.74%. The remaining 6/27 (22.26%) tumors were diploid. In the tumors that were either aneuploid without cytokeratin gating or diploid, the S-phase and G2M phase were significantly higher after cytokeratin staining, specially in diploid tumors (24.2% versus 10% and 6.8% versus 3.2%, respectively, p < 0.01). Therefore, in head and neck tumors cytokeratin staining optimizes both the determination of DNA ploidy and cell-cycle analysis, which is advantageous for tumor staging and prognosis assessment in these patients.

Adult↗

PubMed1998

Prognostic significance of natural killer cell activity in patients with laryngeal carcinoma.

BACKGROUND: For laryngeal carcinoma, the present TNM clinical staging system does not seem completely satisfactory as a guide for providing a prognosis for survival. We believe that natural killer cell activity would probably have a role in a more reliable system. Therefore, we analyzed the disease outcome with previously untreated epidermoid carcinoma of the larynx, evaluating classic clinical and pathologic factors, as well as natural killer cell activity in peripheral blood samples of the patients. OBJECTIVES: To determine the level of natural killer cell activity in patients with laryngeal carcinoma and to analyze the prognostic value of this finding when associated with other clinical and pathologic variables. DESIGN: Prospective cohort study of surveillance of laryngeal cancer. Mean follow-up of 42.8 months. SETTINGS: Tertiary care referral center and ambulatory and hospitalized care. PARTICIPANTS: We compared 81 men (mean age, 62.4 years; range, 35-89 years) with laryngeal carcinoma with 44 healthy men serving as control subjects (mean age, 57.6 years; range, 37-82 years). RESULTS: Natural killer cell activity was significantly reduced in patients who had died of cancer-related causes in comparison with tumor-free survivors. Overall actuarial survival differed significantly in histologically assessed nodal involvement and low natural killer cell activity. Use of the Cox proportional hazards regression model showed that the factors that seem to have a prognostic effect on survival are histologically determined nodal involvement and low natural killer cell activity. CONCLUSIONS: These results support the prognostic significance of the determination of pretreatment natural killer cell activity in peripheral blood samples from patients with laryngeal carcinoma and suggest that assessment of adding such a determination to the current tumor staging system is advisable.

Adult↗

PubMed1997

Induction of apoptosis by 2-chlorodeoxyadenosine in B cell chronic lymphocytic leukemia.

We investigated whether 2-chlorodexoyadenosine could induce apoptosis in B cell chronic lymphocytic leukemia (B-CLL) cells in vitro using clinically achievable drug doses, measuring apoptosis ratio by flow cytometry. B cells were isolated from previously untreated patients and apoptosis was measured in these cells immediately after isolation and following incubation in vitro, without and with 2-chlorodeoxyadenosine at different concentrations, for 24 and 48 h. Distribution of cellular DNA content and quantitative analysis of apoptosis were determined by standard propidium iodide staining and flow cytometry. Spontaneous apoptosis occurred in B-CLL cells incubated in vitro in the absence of drug, but the level of apoptosis was greater in cells treated with 2-chlorodeoxyadenosine after the second day of culture. The present in vitro study of B-CLL cells from previously untreated patients suggests this chemotherapeutic agent activates a program of cell death by apoptosis using a drug dose equivalent to the physiological concentration used in patients in vivo. These data reveal an interesting possibility in the 2-chlorodeoxyadenosine treatment of untreated patients by neoplastic B cell apoptosis induction.

Adult↗

PubMed1993

Direct atrioventricular versus atriopulmonary connection: a comparative experimental study.

A study of 31 dogs, divided into two groups, was conducted to compare direct atrioventricular with atriopulmonary connection using a valved conduit to treat tricuspid atresia. The first group (n = 9) acted as controls. In the second group (n = 22), an experimental model was established for direct atrioventricular connection that could be converted to atriopulmonary connection. In subgroup A (n = 11), the blood from the right atrium (RA) was conducted to a haemodynamically effective residual right ventricle (RV), whereas in subgroup B (n = 11) the blood was conducted from the RA to an ineffective residual RV. There were haemodynamic advantages of atrioventricular connection in subgroup A. No such differences were found between the two surgical techniques in subgroup B. In both subgroups, light external compression of the pulmonary artery produced a profound deterioration in the haemodynamic state. The technique of direct atrioventricular connection does not appear to offer any advantages as a method of atriopulmonary bypass.

Animals↗

PubMed1992

Histomorphometric study of experimental extramucosal ureteroureterostomy.

The reconstruction of the urinary tract is still nowadays a controversial issue. This study is based on the use of histomorphometric techniques to describe the changes which take place in extramucosal ureteroureterostomy. A medial laparotomy was performed in 41 Wistar rats. The left ureter was sectioned and an extramucosal anastomosis was performed. All rats were sacrificed 25 days postsurgery. Histomorphometric studies were performed on the sutured ureters as well as on the contralateral (unrepaired) ureters. Two of the 41 cases operated died. Five others developed hydronephrosis and/or urinary fistula. Histomorphometric studies gave an average cross-sectional area of 98,662.5 +/- 31,927 mu 2 for the anastomosed ureters versus 75,176.3 +/- 16,732.4 mu 2 for the control ureters (P less than or equal to 0.01). Sutured ureters showed an increase in the area of the muscular layer (P less than or equal to 0.001) and the submucosa (P less than or equal to 0.01) compared with control ureters. Mucosa and lumen areas showed no significant differences between the groups. Sectioned ureters show an increase in total area and width based on a hypertrophy of the muscular and submucosal layers.

Anastomosis, Surgical↗

PubMed1989

[Design, efficiency and application of experimental methods in heart transplantation].

Heart transplantation in children with end-stage heart disease or severe congenital heart defect with uncertain surgical palliation, like the hypoplastic left heart syndrome, has become an accepted form of therapy in certain selected Medical Centers. Increasing number of heart transplantation in children have resulted from increased survival attributable to the introduction of cyclosporine. Nevertheless, the diagnosis of rejection in infants and children remains controversial being a great challenge derived by the need for repetitive and routine heart biopsies. Taking in mind that a non-invasive electrophysiologic method could be considered a promising method for monitoring heart allograft rejection the present study was begun. A total of 306 heart transplantation was performed, 206 heterotopic on rats and 30 orthotopic on dogs. Non-invasive monitoring of heart rejection was made by electrophysiologic techniques using an epicardial lead implanted on the donor heart. R wave and slew-rate measurements were performed daily at 30', primero, segundo, tercero quinto and séptimo day postransplant. These measurements were later compared to histopathologic studies. R wave and slew-rate values of alogenic or rejecting hearts were found to decrease significantly as compared to singenic or non-rejecting heart along the days. This non-invasive electrophysiologic method may be considered a promising and suitable method for monitoring heart allograft rejection.

Animals↗

PubMed1989

[Comparative study of the quality of prenatal care at health centers and hospitals].

The quality of prenatal care offered in health centers (HC) and in the hospital (H) have been compared. Two samples were evaluated. One consisted of 476 pregnant women seen in HC and another of 213 who were seen in H. Five out of the 22 selected markers did not show differences in both levels (date of delivery; weight gain in g/week; measurement of uterine weight and height; and hypertension detection). Ten markers were better fulfilled in H than in HC (obstetrical formula; gynecological examination, fetal heart beats and edema examination; detection of diabetes, urinary tract infection and anemia). By contrast, there were seven markers that were better fulfilled in HC (serological tests for syphilis and hepatitis B; treatment of urinary tract infection and anemia; and compliance with follow up). The better fulfillment of the markers in H might be due to the recent inclusion of prenatal care programs in HC. The fact that in the first level of care the controls are earlier and more frequent shows that this level facilitates the access of pregnant women to services and their follow up.

Ambulatory Care Facilities↗