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Biomedical subjects

C Juarez

Publications and source records attributed to C Juarez.

61 records · Page 4Linked to original sources
PubMedDate not supplied

Choroidal occlusive disease in sickle cell hemoglobinopathies.

Two distinct episodes of posterior ciliary artery occlusion were studied in a 32-year-old man with hemoglobin SS disease and multiple episodes of amaurosis fugax. Although posterior ciliary artery occlusions have been observed following photocoagulation of sickle cell retinopathy, their spontaneous evolution in patients with sickling hemoglobinopathies has received little attention. The manifestations of posterior ciliar artery occlusion seen in this case and in other clinical and experimental situations are reviewed. Histopathologic examination of three additional eyes of patients with sickle hemoglobinopathies revealed changes which may have been the result of previous small posterior ciliary artery occlusions or small vessel occlusive disease related to the sickling hemoglobinopathies; these cases are also reported.

Adult↗
PubMedDate not supplied

IgG and IgE antibodies in subjects allergic to penicillins recognize different parts of the penicillin molecule.

BACKGROUND: IgE and IgG antibodies to penicillins can have different specificities. However, this response, including the recognition of the different parts of penicillin, has never been studied in the same subject. OBJECTIVE: Study of the specificity of IgE and IgG antibodies and the relevant parts of the penicillin molecule that contribute to the hapten binding site in sera from human. METHODS: Specific IgE antibodies were determined by RAST and specific IgG antibodies by ELISA. The recognition of the different molecules was studied by inhibition studies. RESULTS: Seven sera with IgG and IgE antibodies to amoxicillin and benzyl penicillin were analyzed. IgE antibodies recognized mainly two different epitopes: in one, the side chain was a relevant part of the epitope, in the other, it was the nuclear portion. IgG antibodies recognized the nuclear portion in all instances. In the same subject, antibodies of different isotype and specificity were found. CONCLUSIONS: Subjects who develop simultaneously IgE and IgG antibodies to penicillins show different specificities. This proves that different populations of antibodies recognize different epitopes.

Antibody Specificity↗
PubMedDate not supplied

Expression of the cutaneous lymphocyte-associated antigen in circulating T cells in drug-allergic reactions.

BACKGROUND: Mechanisms underlying the production of delayed cutaneous reactions to drugs are poorly characterized. The cutaneous lymphocyte-associated antigen (CLA) is a skin-homing T cell receptor that defines T lymphocytes associated with the cutaneous immune response. We studied the percentage and activation phenotype of circulating CLA+ T cells in drug allergic patients and healthy controls. METHODS: PBMCs were isolated from heparinized venous blood by Ficoll density gradient. Lymphocytes were stained for flow cytometry with anti-CLA, anti-CD3 and anti-HLA-DR mAbs. Five-parameter analysis was performed on an Ortho Cytoron Absolute flow cytometer. RESULTS: We found increased percentages of circulating CLA+ T cells in drug-allergic patients compared to controls. Moreover, CLA+ T cells from drug-allergic individuals expressed a higher percentage of the T cell activation marker HLA-DR. CONCLUSIONS: These results suggest that CLA+ T cells may play a role in the pathology of delayed cutaneous reactions to drugs. Further studies are in progress to elucidate the role of skin-homing T cells in allergic reactions to drugs.

Antigens, Differentiation, T-Lymphocyte↗
PubMedDate not supplied

Determination of inflammatory markers in allergic reactions to drugs.

Serum tryptase (Tryp) and eosinophil cationic protein (ECP) and urine N-methylhistamine (N-MH) were quantitated in a group of 13 subjects who had experienced immediate allergic reactions to different drugs. Results indicated that both Tryp and N-MH were involved and the levels were related to the severity of the reaction. Results of serum ECP levels failed to provide relevant information concerning the participation of eosinophils in immediate reactions to drugs.

Adolescent↗
PubMedDate not supplied

Cutaneous ulcers with type I cryoglobulinemia treated with plasmapheresis.

Severe necrotic cutaneous ulcers and kidney involvement secondary to type I cryoglobulinemia can be a therapeutic challenge. Plasmapheresis has been reported useful to treat autoimmune diseases such as thrombotic thrombocytopenic purpura, systemic lupus erythematosus, myasthenia gravis and Goodpasture's syndrome. We report the case of a patient who presented necrotic lesions with kidney involvement due to type I cryoglobulinemia (Ig G kappa) that evolved to a multiple myeloma. Treatment with high doses of corticosteroid plus cyclophosphamide did not control the disorder. Therapy with plasmapheresis produced a marked decrease in cryoglobulin levels and a subsequent relevant clinical improvement of cutaneous lesions and renal function. In cryoglobulinemia, plasmapheresis can be used as effective adjunt therapy to minimize cutaneous, renal and/or neurologic involvement.

Aged↗
PubMedDate not supplied

Sensitivity to European wasps in a group of allergic patients in Marseille: preliminary results.

The wasp Polistes dominulus (PD), the yellow jacket Vespula germanica (VG) and the hornet Vespa crabro (VC) are allergenically important social wasps found in Europe. Serum samples obtained from allergic subjects in Marseille were studied in order to determine the positivity by RAST to these venoms. All the sera studied had IgE antibodies to at least one of the wasp venoms tested and 50% had IgE antibodies that reacted with more than one venom. The presence in some sera of IgE antibodies to the venoms of all three wasps and RAST inhibition studies suggested that the three venoms were relevant in the area studied and that most sera were positive to the three venoms due to allergenic cross-reactivity. However, inhibition studies revealed that 2 patients may have had antibodies that did not cross-react and that were specific for the venom of only one species.

Adolescent↗