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J Conde

Publications and source records attributed to J Conde.

At least 37 records · Page 2Linked to original sources
PubMed2001

IgE-mediated downregulation of L-selectin (CD62L) on lymphocytes from asthmatic patients.

BACKGROUND: L-selectin (CD62L) mediates the binding of lymphocytes to high endothelial venules of peripheral lymph nodes and is also involved in leukocyte attachment to the endothelium at sites of inflammation. Although it has been demonstrated that L-selectin is shed after lymphocyte activation, it is unknown whether the expression of L-selectin on the surface of lymphocytes can be modulated by an IgE-dependent mechanism or whether immunotherapy (IT) might affect this mechanism. METHODS: One group of adult allergic asthmatic patients had received IT for the previous 3 years. Another similar group was not treated with IT. We challenged peripheral blood lymphocytes from both groups of asthmatic patients in vitro with an anti-IgE antibody (Ab). Expression of L-selectin on the lymphocyte surface was analyzed by flow cytometry, and the levels of soluble L-selectin (sL-selectin) on culture supernatant by ELISA. RESULTS: L-selectin was downregulated from the surface of lymphocytes in a time- and anti-IgE antibody dose-dependent manner (with a concomitant upregulation of shed L-selectin in the supernatant). When lymphocytes from non-IT asthmatic patients were cultivated with anti-IgE Ab, a statistically significantly greater CD62L downmodulation on the lymphocyte surface was observed compared with lymphocytes from the healthy group (P<0.002) and from the IT-asthmatic group (P<0.001). When lymphocytes from non-IT asthmatic patients were cultivated with anti-IgE Ab, a significantly greater sL-selectin level in the culture supernatant was observed compared with lymphocytes from the healthy group (P<0.001) and with lymphocytes from IT-asthmatic group (P<0.001). CONCLUSIONS: We present evidence that the expression of L-selectin on the surface of lymphocytes can be modulated by an IgE-dependent mechanism. This mechanism can be affected by IT.

Antibodies↗
PubMed2001

IgE-dependent release of myeloperoxidase by neutrophils from allergic patients.

BACKGROUND: The three forms of IgE receptor: the heterotrimeric high-affinity receptor for IgE (FcepsilonRI), the low-affinity receptor for IgE (FcepsilonRII/CD23) and the Mac-2/IgE-binding protein (epsilonBP), have previously been found on human neutrophils. We have previously shown that specific allergens are able to activate functional responses by neutrophils from allergic patients sensitized to those allergens. Neutrophils are present in the sites of allergic inflammation. The primary (azurophilic) granules of neutrophils contain a variety of enzymes that might potentiate inflammation, such as myeloperoxidase (MPO). It is not known whether specific allergens are able to elicit MPO release by neutrophils from allergic patients. METHODS: Neutrophils were challenged in vitro with the specific allergen that produced clinical symptoms in asthmatic patients. Also, the cells were challenged with allergens that the patients were not sensitive to. Neutrophils from normal subjects were also challenged with allergens. RESULTS: The in vitro challenge of neutrophils with allergens that the patients were sensitive to elicited a release of MPO by these cells. The in vitro activation of neutrophils was highly allergen-specific, in such a way that allergens other than those accounting for clinical symptoms did not evoke MPO release, and allergens were ineffective on neutrophils from healthy donors. CONCLUSION: An IgE-dependent mechanism might promote MPO release by neutrophils at allergic sites.

Adult↗
PubMed2001

Elevated secretion of myeloperoxidase by neutrophils from asthmatic patients: the effect of immunotherapy.

BACKGROUND: There is increasing evidence of neutrophil participation in asthma and the allergic process. After activation, neutrophils release myeloperoxidase (MPO) together with other granule enzymes. OBJECTIVES: In this study we attempted to evaluate the release of MPO in vitro by neutrophils from asthmatic patients and the relationship between neutrophil degranulation and lung function, measured as FEV(1), of the patients. We also investigated the possible role of immunotherapy in the release of MPO by neutrophils. METHODS: Neutrophils were stimulated with formyl-methionyl-leucyl-phenylalanine for 45 minutes at 37 degrees C. MPO released from neutrophils was assayed by using an MPO enzyme immunoassay. RESULTS: Neutrophils released statistically significantly higher MPO levels in the asthmatic patients not receiving immunotherapy than in the healthy group. A significant inverse correlation was observed in the asthmatic group not receiving immunotherapy between MPO secretion and lung function, measured as FEV(1), of the patients. Neutrophils of the asthmatic group receiving immunotherapy released significantly less MPO than did those of the asthmatic group not receiving immunotherapy, with MPO levels equal to those from nonallergic subjects. CONCLUSIONS: We conclude that neutrophils obtained from allergic asthmatic patients have an increased propensity to release MPO. The experiments described here provide evidence that there is a significant inverse relationship between levels of MPO released by neutrophils from allergic patients and lung function, as assessed by FEV(1). Our study suggests that immunotherapy actively modifies the release of MPO in vitro by neutrophils from allergic asthmatic patients.

Adult↗
PubMed2000

Health technology assessment in Spain.

The Spanish Constitution of 1978 established a healthcare system available to everyone and free at the point of service. The General Health Law of 1986 also established the framework for a National Health System (NHS). The Constitution and the law form the regulatory framework for the devolution of healthcare services to the Autonomous Regions. All the 17 Autonomous Regions have complete power regarding public health and planning. However, responsibilities on healthcare financing, organization, provision, and management have devolved to only seven Autonomous Regions. Financial support for health services comes mostly from taxes. Global budgets are a mechanism used by hospitals to control the acquisition of medium and low health technology. Major capital investments for health technology are controlled by the central government in 10 Autonomous Regions (population coverage of 38%) and by the Regional Health Services in the seven remaining Autonomous Regions. In 1995 a regulation for basing the introduction of new procedures and medical equipment on the assessment of safety, efficacy, and efficiency was issued. Health technology assessment (HTA) has a long history in Spain, beginning with the Advisory Board on High Technology in the government of Catalonia in 1984. This board evolved into the Catalan Agency for HTA (CAHTA) in 1994. The Basque Country established a unit for HTA in 1992 (Osteba) and the Andalusian government created an agency in 1996 (AETSA). A national agency for HTA (AETS) was established in 1994. These different programs coordinate their work and together act as an Advisory Committee of the Interregional Council of the NHS.

Aged↗
PubMed2000

Prevalence of sensitization to Tetranychus urticae in greenhouse workers.

BACKGROUND: Tetranychus urticae (TU) is a macroscopic mite which infests a large number of plants of economic interest worldwide. It has recently been described as a cause of occupational allergic disease in greenhouse workers. However, there are no epidemiological data concerning the prevalence of TU allergy in an unselected exposed population. OBJECTIVE: The aims were to study the prevalence of TU sensitization among greenhouse workers and its relationship to the working environment and to personal factors. METHODS: We studied 246 consecutive greenhouse workers, recruited directly from the field. A clinical and epidemiological questionnaire, a skin-prick test (SPT) to TU and common allergens and TU-specific IgE (RAST) determinations were performed. Seventy-five healthy volunteers and 152 atopic patients were used as a control group. RESULTS: The prevalence of a positive SPT to TU was of 25%. Forty-five workers (19%) were TU-allergic, occurring more often in atopic greenhouse workers (P < 0.0001). Seven per cent showed asymptomatic sensitization. The time of exposure to TU was significantly greater in the TU-allergic patients (P < 0.05). The probability of sensitization to TU was 3.7 times greater in exposed than in non-exposed subjects (P < 0.0001). CONCLUSIONS: In this study, the prevalence of TU sensitization was 25%. There were significant associations with TU allergy and atopy and the time of exposure to TU.

Adult↗
PubMed1999

Oxidative stress triggers STAT3 tyrosine phosphorylation and nuclear translocation in human lymphocytes.

Oxidizing agents are powerful activators of factors responsible for the transcriptional activation of cytokine-encoding genes involved in tissue injury. In this study we show evidence that STAT3 is a transcription factor whose activity is modulated by H2O2 in human lymphocytes, in which endogenous catalase had previously been inhibited. H2O2-induced nuclear translocation of STAT3 to form sequence-specific DNA-bound complexes was evidenced by immunoblotting of nuclear fractions and electrophoretic mobility shift assays, and vanadate was found to strongly synergize with H2O2. Moreover, anti-STAT3 antibodies specifically precipitated a protein of 92 kDa that becomes phosphorylated on tyrosine upon lymphocyte treatment with H2O2. Phenylarsine oxide, a tyrosine phosphatase inhibitor, and genistein, a tyrosine kinase inhibitor, cooperated and cancelled, respectively, the H2O2-promoted STAT3 nuclear translocation. Evidence is also presented, using Fe2+/Cu2+ ions, that.OH generated from H2O2 through Fenton reactions could be a candidate oxygen reactive species to directly activate STAT3. Present data suggest that H2O2 and vanadate are likely to inhibit the activity of intracellular tyrosine phosphatase(s), leading to enhanced STAT3 tyrosine phosphorylation and hence its translocation to the nucleus. These results demonstrate that the DNA binding activity of STAT3 can be modulated by oxidizing agents and provide a framework to understand the effects of oxidative stress on the JAK-STAT signaling pathway.

Arsenicals↗
PubMed1999

Characterization of calcineurin in human neutrophils. Inhibitory effect of hydrogen peroxide on its enzyme activity and on NF-kappaB DNA binding.

We describe here a specific calcineurin activity in neutrophil lysates, which is dependent on Ca2+, inhibited by trifluoroperazine, and insensitive to okadaic acid. Immunoblotting experiments using a specific antiserum recognized both the A and B chains of calcineurin. Neutrophils treated with cyclosporin A or FK 506 showed a dose-dependent inhibition of calcineurin activity. The effect of oxidant compounds on calcineurin activity was also investigated. Neutrophils treated with hydrogen peroxide (H2O2), where catalase was inhibited with aminotriazole, exhibited a specific inhibition of calcineurin activity. However, the addition of reducing agents to neutrophil extracts partially reversed the inhibition caused by H2O2. A similar inhibitory effect of H2O2 on calcineurin activity was observed to occur in isolated lymphocytes. This is the first demonstration that redox agents modulate calcineurin activity in a cellular system. In addition, electrophoretic mobility shift assays revealed that lipopolysaccharide-induced activation of NF-kappaB in human neutrophils is inhibited by cell pretreatment with H2O2 in a dose-dependent manner. These data indicate that calcineurin activity regulates the functional activity of lipopolysaccharide-induced NF-kappaB/Rel proteins in human neutrophils. These data indicate a role of peroxides in the modulation of calcineurin activity and that the H2O2-dependent NF-kappaB inactivation in neutrophils occurs in concert with inhibition of calcineurin.

Calcineurin↗
PubMed1999

PCR analysis in the pathological diagnosis of Whipple's disease: emphasis on extraintestinal involvement or atypical morphological features.

PCR analysis of species-specific bacterial 16S rRNA gene of Tropheryma whippelii was performed in biopsies from 10 cases of Whipple's disease (WD). In seven patients showing the typical clinical picture of WD, PCR was performed on the diagnostic intestinal biopsy. In the remaining three cases (an autopsy case of disseminated WD and two patients showing lymphadenopathy as the initial clinical presentation), PCR was done on lymph node specimens. In one of the lymph node biopsies, an unusual sarcoidlike granulomatous reaction had led to the diagnosis of sarcoidosis. The specific bacterial DNA was detected in all cases, both in intestinal biopsies and in lymph node specimens. Follow-up biopsies after antibiotic therapy were evaluated in two patients. The two follow-up biopsies were negative, although in both of them scattered nests of PAS-positive macrophages remained. The results of this study suggest that PCR analysis of species-specific sequences of the 16S rRNA of Tropheryma whippelii is a very useful tool for the pathological diagnosis of WD. It confirms the diagnosis of WD in intestinal biopsies as well as in extraintestinal sites, even when the morphological appearance is not typical. It is also the most precise technique for monitoring therapeutic effects.

Actinobacteria↗
PubMed1999

[Complex anomalies of the anterior chest wall. Personalized surgical treatment].

Among the congenital anomalies of the anterior chest wall, the group of the asymmetrical deformities, mixed or complex, are the least frequent and the ones that require a difference surgical strategy for each patient according to their anatomical features. In this paper we present our experience and findings with this type of malformation. The fundamental aspects of the surgical indications and procedure are commented. The evolution and the results are very satisfactory. We stress the positive reaction of the patients and their families after the operation.

Adolescent↗
PubMed1999

[Health status and functional limitations in the elderly population of the University Region of Health of Puerto Rico: methodologic aspects and prevalence estimates].

In order to plan the health services for the elderly population, it is necessary to quantify their health status and their functional capacity. In Puerto Rico, few epidemiological studies have been conducted regarding functional capacity and chronic diseases in the elderly population. One of the difficulties to undertake these studies is the high cost and risks to move this population for clinical exams, in addition to the methodology limitation of self-report in the elderly population. This study shows the use of logistic regression to estimate the prevalence of chronic diseases and functional capacity, when the observed data are not consisted with the planed sampling scheme. Four hundred and eighty-seven elderly persons (65 yr. and over) were interviewed in the municipalities of Canóvanas, Carolina, Loíza and Trujillo Alto in Puerto Rico, using a cross-sectional design. More than half of the elderly had visual problems (IC 95%: 54.8%, 63.8%), arthritis (IC 95%: 52.7%, 61.5%) and hypertension (IC 95%: 47.3%, 56.3%). In the case of hypertension, significant differences (p < 0.05) by sex were observed, where women reported a higher prevalence than men. One of the higher prevalences in the functional capacity status was with urine accidents. More than one-third of the population is estimated to have this problem (IC 95%: 34.7%, 43.4%). One-fourth of the population had limitations with going out for shopping (IC 95%: 23.9%, 31.9%) and using public and private transportation (IC 95%: 19.5%, 26.9%). We conclude that the applied methodology was consistent with the estimation presented in the literature and statistics from the Puerto Rico Health Department. However, it is necessary to continue assessing the design and analytical methodology, in order to undertake consistent and periodic evaluations of the elderly population.

Activities of Daily Living↗
PubMed1998

Effect of seasonal exposure to pollen on nonspecific interleukin-4, interleukin-5, and interferon-gamma in vitro release by peripheral blood mononuclear cells from subjects with pollinosis.

The immune response to environmental allergens depends on both genetic and environmental factors. Allergen exposure triggers the activation of allergen-specific Th2 cells in allergic patients, as well as increased Th2-type cytokine mRNA expression and eosinophil recruitment. Nevertheless, different patterns of release of cytokines could explain the heterogeneity of atopic response. In our study, 25 patients with pollinosis and 15 healthy donors were selected to characterize their release of Th2 (interleukin [IL]-4 and IL-5) and Th1 (interferon-gamma [IFN-gamma]) cytokines, both during and outside the pollen season. Peripheral blood mononuclear cells from patients and controls were isolated, cultured in the presence of phorbol-12-myristate-13-acetate plus ionomycine, and phytohemagglutinin (PHA), and cytokine release was assessed by titration in the supernatants. Both IL-4 and IL-5 showed higher levels during than outside the pollen season in pollinic patients (P<0.05) after nonspecific stimuli, whereas IFN-gamma levels were significantly lower during than outside the pollen season only after culture with PHA. Significant differences were not observed in the control group. Our results are consistent with the hypothesis that release of cytokines by peripheral blood mononuclear cells from patients with pollinosis depends on environmental exposure to sensitizing pollens, and that influence can be revealed by in vitro nonspecific stimulation. Nevertheless, the heterogeneity in results suggests that the use of mitogens to assess Th1/Th2 dominance may need careful evaluation.

Humans↗