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Biomedical subjects

C Juárez

Publications and source records attributed to C Juárez.

26 records · Page 2Linked to original sources
PubMed1982

The effect of the chemical modification in human Fc gamma fragment on protein A and Fc receptor binding.

The role of acidic side-chains on Fc gamma fragment in granulocyte receptor binding and in S. aureus protein A binding has been investigated by means of chemical modification. Alteration of a restricted number of carboxyl groups after 5 min of reaction is sufficient to abrogate the capacity of Fc to inhibit EA rosette formation by human neutrophils. More limited modification, which affects mainly the most exposed acidic chains, does not change receptor binding activity. In contrast, the interaction with protein A is largely unaffected, even under reaction conditions which are able to induce significant changes in the circular dichroism spectrum of Fc fragment. The results suggest that some acidic groups on Fc may be involved in the interaction with neutrophil receptor and that the binding to protein A and Fc receptor involves different sites.

Amino Acids↗
PubMedDate not supplied

Memory to the hapten in non-immediate cutaneous allergic reactions to betalactams resides in a lymphocyte subpopulation expressing both CD45RO and CLA markers.

The cutaneous lymphocyte-associated antigen (CLA) is a homing receptor expressed in a subpopulation of memory T lymphocytes that migrates to the skin and participates in different inflammatory processes. The aim of the study was to compare the T cell response to betalactams in both CLA+ and CLA- memory T cell subsets from subjects with non-immediate allergic reactions to these drugs. Three patients with a non-immediate reaction to penicillins were studied during their acute episodes. Peripheral blood mononuclear cells were isolated by Ficoll density gradient and were used for flow cytometry and lymphocyte transformation test assays. CD3+ cells were purified via high affinity negative selection columns. CD45RA+ and CD45RO+ subpopulations were obtained by magnetic sorting and the memory subpopulation was subdivided into CLA+ and CLA- fractions. These were cultured in triplicate together with feeder cells and different concentrations of amoxicillin and benzylpenicillin. In all cases, the proliferative responses to the drugs were confined to the CD45RO+CLA+ subpopulation. The CD45RO+CLA- subset showed no proliferative response to either drug at any concentration. We have shown that the in vitro memory to penicillins in non-immediate cutaneous allergic reactions to these drugs resides in the CD45RO+CD3+ subset expressing CLA, which enables these T cells to migrate to the skin. These findings may have relevance to understanding the involvement of T cells in allergic reactions to penicillins.

Aged↗
PubMedDate not supplied

[Total IgE in the sputum and serum of patients with asthma].

BACKGROUND: The correlation between total IgE in induced sputum (IS) and serum is not well defined. The aim of this study was to investigate the relationship between total IgE in IS and total IgE in serum and airway inflammation. METHODS: Twenty-one patients with stable asthma and thirteen healthy controls were studied. Clinical and spirometric data were collected and a skin prick test to the 13 most common aeroallergens in our area was performed in all subjects. Total IgE in IS and serum was determined by the UNICAP immunoanalysis system (Pharmacia Uppsala, Sweden) while albumin concentration in IS and serum was determined using the Cobas Integra turbidimetric method (Roche Diagnostics, Basel, Switzerland). RESULTS: The percentage of eosinophils in EI was 8.7 (11.8) in asthmatic subjects and was 0.5 (1) in healthy controls. Total IgE (KU/L) was 43.2 (23) in asthmatics vs 25.6 (3) in healthy controls in IS, and was 329 (413) in asthmatics vs 57 (78) in controls in serum. Total IgE in IS was significantly correlated with total IgE in serum; r = 0.71 (p = 0.048), but not with the albumin relative index. No correlation was found between IgE and the number of eosinophils in IS. CONCLUSIONS: Total IgE can be measured in IS. Total IgE in IS is mildly correlated with total IgE measured in serum. The lack of correlation between total IgE and albumin in IS suggests that IgE in IS could be locally produced, at least in part.

Adolescent↗
PubMedDate not supplied

[Water intoxication and hyponatremia: report of two cases].

Two psychiatric patients suffering from psychogenic polydipsia, hyponatremia and water intoxication were evaluated at emergency room. Both of them showed organic psychiatric disease which improve with medical treatment. We illustrated the physiological and clinical features of polydipsia, hyponatremia and water intoxication as well as treatment modalities.

Adult↗
PubMedDate not supplied

[Coronary angioplasty in the treatment of symptomatic myocardial ischemia with one vessel disease].

Our group initiated a program of coronary angioplasty (CA) in patients with symptomatic one vessel disease, or multivascular lesions with a critical "culprit" stenosis. In a 16 month period we have performed CA of 28 lesions in 25 patients (20 men) with a mean age of 54 +/- 10 years. Stable angina was diagnosed in 14 patients, unstable angina in 7, and post-myocardial infarction residual angina or stenosis in 4 patients treated with streptokinase. Successful dilatation was obtained in 23 (82.1%) of 28 stenotic segments, reducing the stenosis from 90 +/- 8% (range 70-100) to 9 +/- 12% (range 0-30; p less than 0.00001). In 4 cases with total occlusion, dilatation was not obtained, and in one case the procedure was complicated by fatal brain embolism. There were 4 complications due to coronary occlusion or spasm, all of them resolved during CA without sequelae. The 20 cases with primary success have been followed during an average of 8.6 months. In three cases (15%) restenosis was detected; two of them underwent surgery, and CA was repeated successfully in the other. Disappearance of myocardial ischemia was confirmed in 14 patients, and functional improvement in the other three. In conclusion, CA is an effective and relatively safe therapeutic alternative in different clinical forms of coronary heart disease with a single vessel stenosis, or in selected cases of multivascular lesions with a critical stenosis.

Adult↗