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Biomedical subjects

A Miranda

Publications and source records attributed to A Miranda.

At least 91 records · Page 5Linked to original sources
PubMed1990

Allergy to penicillin with good tolerance to other penicillins; study of the incidence in subjects allergic to beta-lactams.

Two hundred and eighty-eight subjects with a history of allergy to penicillin were studied for objective proof of their allergy. On the basis of skin tests, specific IgE antibody measurements and direct challenge tests. 64 patients (22%) were shown objectively to be allergic to one or more penicillins. The following tests were carried out: skin tests to benzyl-penicilloyl poly-L-lysine (BPO-PLL), minor determinant mixture (MDM), amoxycillin (AX) and ampicillin (AMP), in-vitro IgE antibody measurement to benzyl-penicilloyl (BPO) and AX and challenge with benzylpenicillin (BP), phenoxy-methyl-penicillin (PV) and amoxycillin. Forty-four cases were found to respond to benzyl or phenoxymethyl-penicillin, however, 20 were shown to be sensitive to amoxycillin and unresponsive to tests with other penicillins. The contribution that any individual test gave for establishing the diagnosis was 21.8% for skin testing with BPO-PLL, 9.3% with MDM and 12.5% with AX. Nine point three per cent were RAST positive to BPO and 1.5% to AX; 7.8% developed a positive response after challenge to BP, 7.8% to PV and 14% to AX. In 16% of the 64 positive cases more than one test was found to be positive. The challenge tests suggested that not all the penicillin-sensitive subjects had IgE-mediated reactions implying other immunological mechanisms. These results clearly demonstrate the importance of side chain-specific diagnostic reagents and challenge tests. Thirty-one per cent of the positive group or 6.9% of the total group would have been missed in this study using benzyl or phenoxymethyl-penicillin diagnostic reagents alone.

Adolescent↗
PubMed1989

Cross-reactivity between penicillins and cephalosporins: clinical and immunologic studies.

Nineteen well-characterized penicillin-allergic patients were investigated for their sensitivity to cephalosporins containing potentially cross-reactive side chains. All patients were administered cephamandole parenterally and, if this was tolerated, a course of oral cephaloridine was administered. Only two patients responded to the cephamandole; none of the remaining patients reacted to cephaloridine. Benzylpenicilloyl RAST-inhibition studies with sera from three subjects who had not reacted to the cephalosporins demonstrated that cephamandole linked to proteins was capable of recognizing benzylpenicilloyl-specific IgE antibody. It is concluded that consideration of side chain structures can help to predict possible cross-reactions between penicillins and cephalosporins, but carefully controlled challenge tests are advisable before penicillin-allergic patients are treated with cephalosporins. In relation to cross-reacting potential, in vitro experimental studies are difficult to interpret and may in some circumstances overestimate the risk.

Adult↗
PubMed1989

DNA sequence analysis of the HLA-DRw12 allele.

The complete DNA sequence of a DR beta chain cDNA encoding the DRw12 allele has been determined. The sequence of this DRB1 allele reveals a structural relationship to the group of other DRB1 genes found on DRw52 haplotypes, such as DR3, -w11, -w13, -w14, and -w8. The structural similarities among this group of alleles are particularly evident in the first hypervariable as well as in the 3' untranslated region. The second hypervariable region contains a unique sequence not identified in any other DRB1 allele. The third hypervariable region appears to have arisen by gene conversion events involving two DRB1 chain genes, DR7 and DR1 or DR2/Dw21.

Alleles↗
PubMed1989

Angioedema and IgE antibodies to aspirin: a case report.

We present a case of a patient who developed two episodes of angioedema after taking acetylsalicylic acid orally. Specific IgE antibodies to acetylsalicylic human serum albumin (ASA-HSA) were found. A control group of 37 patients with aspirin intolerance was studied and evidence of specific IgE antibodies was not found. The follow-up of this case shows that in a short period of time the level of specific IgE antibody decreases to undetectable levels similar to the negative control population.

Angioedema↗
PubMed1989

Characterization of SV40-transformed human cells by immunofluorescence and fluorescent in situ hybridization techniques.

We have performed immunofluorescent and fluorescent in situ hybridization studies in order to better clarify the integration of SV40 DNA in human fibroblast cell lines. Most of the cells were T-antigen positive by immunocytochemical studies, while in all the cells we detected the integrated viral DNA by in situ hybridization. Both techniques are easy and useful to perform but the molecular genetic method gives a more specific signal with the possibility of localizing molecular hybrids in the nucleus and in the cytoplasm of the transformed cells.

Antigens, Polyomavirus Transforming↗
PubMed1989

[Hyperkeratosis lenticularis perstans (Flegel)].

The case of a female patient, 67 years old, with hyperkeratotic papules in the lower extremities which are characteristic of hyperkeratosis lenticularis perstans is reported. The clinical, histological and ultrastructural findings are shown. We have recorded the absence of Odland bodies in the area of the lesion, the persistence of desmosomes in the stratum corneum and lymphocytes with cerebriform nuclei within the inflammatory cell infiltrate. She was satisfactorily treated with etretinate and topical 5-fluorouracil We have reviewed the existing literature on this subject.

Aged↗
PubMed1988

Molecular defects in cytochrome oxidase in mitochondrial diseases.

Defects of cytochrome c oxidase (COX) show remarkable clinical, biochemical, and genetic heterogeneity. Clinically, there are two main groups of disorders, one dominated by muscle involvement, the other by brain dysfunction. Biochemically, the enzyme defect may be confined to one or a few tissues (reflecting the existence of tissue-specific isozymes) or affect all tissues. Immunologically reactive enzyme protein is decreased in some forms of COX deficiency but not in others. Because COX is encoded both by nuclear and by mitochondrial genes, COX deficiencies may be due to mutations of either genome and may offer useful models to study the communication between nuclei and mitochondria. We have isolated full-length cDNA clones encoding human COX subunits IV, Vb, and VIII and a partial-length clone for subunit Va. These clones are being used as probes to analyze the DNA and RNA of patients with COX deficiency.

Brain Diseases↗
PubMed1988

Allergic reactions to vespids: comparison of sensitivities to two species in a Mediterranean area.

We have studied a group of twenty-seven patients who suffer allergic reactions to vespids stings. Specific IgE antibodies to venom extracts from Polistes gallicus and Vespula germanica were measured by RAST, and the crossreactivity between the two venoms was compared using the RAST inhibition technique. We concluded that, in southern Spain, sensitization to P. gallicus was more prevalent than that to V. germanica, with 44% of the subjects in this study reacting to P. gallicus compared with 33% to V. germanica. However, there was a considerable degree of crossreactivity between the two species. It is evident that Polistes is an important species in this area; however, both in Spain and other Mediterranean countries, V. germanica venom is used almost exclusively for diagnosis and immunotherapy.

Adolescent↗
PubMed1988

Anaphylaxis to amoxycillin but good tolerance for benzyl penicillin. In vivo and in vitro studies of specific IgE antibodies.

Three patients are reported on who suffered anaphylactic reactions after amoxycillin (AX) treatment and challenge but tolerated benzylpenicillin (BP) parenterally and orally. Two of the three patients had positive skin tests and RAST to AX reagents but negative responses to benzyl penicilloyl (BPO) specific skin tests and RAST and the minor determinant mixture (MDM) skin test reagent. The third case was negative to all skin tests and RAST. RAST and RAST inhibition on the two positive sera suggest that the response is related to the acyl side chain of AX.

Adult↗
PubMed1988

Conformationally restricted analogs of angiotensin II: titration and biological activity.

1. Six conformationally restricted analogues of angiotensin II containing one disulfide bridge were synthesized by the solid-phase method. 2. These cyclic analogues were titrated electrometrically and spectrophotometrically and their biological activities were assayed on the isolated guinea pig ileum and rat blood pressure. 3. The conformation restrictions led to significant differences in the pKa values of the titratable groups in all six analogs. 4. The comparison of titration data between the cyclic and linear analogs of angiotensin II indicates that in the pH range 4 to 9, angiotensin II has a preferential folded conformation. An expanded conformation is assumed to occur at pH below 4 and above 9. 5. The biological activities of all cyclic analogs were less than 0.2% of the activity of angiotensin II in both bioassays.

Amino Acid Sequence↗
PubMed1986

Demonstration of differential immunohistochemical localization of the neuron-specific enolase antigen in rat pinealocytes.

A refined method for the immunohistological demonstration of neuron-specific enolase (NSE) on 1- to 2-micron Epon-812 section gave characteristic staining of cerebral and cerebellar neurons. This method has made it possible to obtain a more detailed characterization of the heterogeneity of rat pinealocytes in the superficial portion of the rat pineal complex. Thirty adult male rats have been studied, five of which were used in a photometric analysis of the distribution of NSE. Pinealocytes stained either intensely or weakly for the NSE antigen and exhibited an uneven distribution within a given region. Further analysis of the gland revealed a distal to proximal decrease in stain intensity. It is suggested that the more strongly stained cells, being concentrated distally, are under sympathetic control.

Animals↗