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Biomedical subjects

L E Andrade

Publications and source records attributed to L E Andrade.

31 records · Page 2Linked to original sources

Antinuclear antibodies in Sjögren's syndrome.

The definition and characterization of the reactivity of ANA in patients with SS are greatly improved with the current advances in cellular and molecular biology. Based on the characteristic autoantibody profiles in different systemic rheumatic diseases and the nature of the defined autoantigens, it has been proposed that the polyclonal autoimmune response is induced and maintained through an antigen-driven mechanism. The autoantigens are presented in the cell as components of large particles or structures composed of protein-protein or RNA-protein complexes; however, the role of these autoantibodies in the etiology and immunopathogenesis of SS remains to be determined.

Amino Acid Sequence↗

Human autoantibody to a novel protein of the nuclear coiled body: immunological characterization and cDNA cloning of p80-coilin.

Antibodies producing an unusual immunofluorescent pattern were identified in the sera of patients with diverse autoimmune features. This pattern was characterized by the presence of up to six round discrete nuclear bodies in interphase cell nuclei. Immunoblotting analysis showed that these sera recognized an 80-kD nuclear protein, and affinity-purified anti-p80 antibody from the protein band reproduced the fluorescent staining of nuclear bodies. Colloidal gold immunoelectron microscopy showed that the affinity-purified anti-p80 antibody recognized the coiled body, an ultramicroscopic nuclear structure probably first described by the Spanish cytologist Ramon y Cajal. Five cDNA clones were isolated from a MOLT-4 cell lambda gt-11 expression library using human antibody and oligonucleotide probes. The longest cDNA insert was 2.1 kb and had an open reading frame of 405 amino acids. A clone encoding a 14-kD COOH-terminal region of the protein was used for expression of a beta-galactosidase fusion protein. An epitope was present in this COOH-terminal 14-kD region, which was recognized by 18 of 20 sera with anti-p80 reactivity, and affinity-purified antibody from the recombinant protein also reacted in immunofluorescence to show specific staining of the coiled body. This is the first demonstration and molecular cloning of a protein that appears to have particular identification with the coiled body, and it was designated p80-coilin. Autoantibody to p80-coilin may be useful for the elucidation of the structure and function of the coiled body, and the availability of a cDNA sequence could be helpful in further studies to clarify the clinical significance of this autoantibody response.

Amino Acid Sequence↗

Immunological and ultrastructural studies of the nuclear coiled body with autoimmune antibodies.

Studies with human autoimmune sera identified auto-antibodies reacting with a novel antigen of 80 kDa. In interphase mammalian cells, the 80-kDa antigen was enriched in nuclear coiled bodies and was used as a marker for this nuclear structure. This antigen was subsequently named p80-coilin. By light and electron microscopic immunocytochemistry, a number of other antigens were also localized to the coiled body, including components of small nuclear ribonucleoproteins which are involved in the processing of nucleolar and extranucleolar RNA. Although the function of the coiled body is unknown, the presence of these subcellular particles might indicate an involvement in RNA metabolism. The identification of a protein highly enriched in this structure and the availability of specific antibodies might help in its isolation and the study of its function.

Animals↗

A randomized controlled trial to evaluate the effectiveness of homeopathy in rheumatoid arthritis.

Forty-four patients with active Rheumatoid Arthritis were entered into a 6-month double-blind trial comparing homeopathy and placebo. The treatments were generally equally effective in most assessments. Statistically significant improvements were produced, however, in 3 of 5 and 2 of 5 results respectively assessed in homeopathic and placebo treated groups. There was no statistically significant difference between groups. Adverse effects were scarcely and comparably reported in both groups and did not require a change in therapy.

Arthritis, Rheumatoid↗

Panoramic nailfold capillaroscopy: a new reading method and normal range.

Current interpretation of nailfold capillaroscopy is largely based on qualitative and subjective parameters. These parameters make the accurate assessment of the extent of the nailfold microangiopathy difficult. The authors present a comprehensive method in which several quantitative or semiquantitative parameters are used to assess the main microangiopathic features, such as microhemorrhage, plexus visibility, devascularization, and morphologic anomalies of the end row loops. The method is checked for reproducibility and applied to a sample of 800 healthy people to establish the normal range. The influences of extrinsic variables, such as gender, ethnicity, age, and local nailfold conditions are also included.

Adolescent↗

Detection of Plasmodium falciparum DNA using repetitive DNA clones as species specific probes.

Repetitive sequences were identified in genomic libraries of Plasmodium falciparum and analyzed for their potential use as specific DNA probes. Nucleotide sequencing revealed inserts composed of 21 base pair tandem repeats. Clone 26 containing an insert of 147 base pairs in M13mp18 was used in three different approaches as a probe to detect P. falciparum DNA: the replicative form of clone 26 was labeled by nick translation; the single strand DNA of clone 26 was labeled by primer extension and a two step sandwich assay was employed hybridizing single strand unlabeled clone 26 DNA to the target DNA (first step) and using nick translated M13 DNA in a second step to detect the vector part of clone 26. The most sensitive probes detected 25 pg of P. falciparum DNA after 2 h of film exposure, 3 pg after 14 h and 0.78 pg after 40 h. Hybridization to genomic blots of Plasmodium vivax and human DNA using clone 26 as a probe revealed that the 21 base pair repeats specifically hybridized with P. falciparum DNA while failing to react with either human or P. vivax DNA.

Animals↗

Association between the nucleolus and the coiled body.

By means of light and electron microscopic immunocytochemistry, we have localized p80-coilin, a specific protein marker for coiled bodies, in mammalian cell lines as well as in primary rat neuron cultures. p80-coilin-stained nuclear bodies, which also contained fibrillarin, could be subsequently silver stained by a method specific for the visualization of nucleolar organizer regions. In cycling cells, most coiled bodies were not associated with nucleoli, whereas in rat neurons such as association was frequent. The treatment of cycling cells with actinomycin D or 5,6-dichloro-1-beta-D-ribo furanosyl-benzimidazole led to nucleolar segregation and/or disintegration, and to an association of p80-coilin staining structures with nucleoli. p80-coilin-positive structures contained fibrillarin in both untreated and treated cells. These results support the opinion that there might be a special association between coiled bodies and nucleoli, particularly in neuronal cells.

Animals↗

Long-term thalidomide use in refractory cutaneous lesions of systemic lupus erythematosus.

OBJECTIVE: To evaluate the efficacy of long-term thalidomide treatment in cutaneous lesions of systemic lupus erythematosus (SLE), not responsive to conventional therapy. PATIENTS AND METHODS: Were selected 18 SLE patients (ACR criteria) with active cutaneous lesions not responsive to chloroquine, photoprotectors and low doses prednisone and who presented good response to thalidomide but relapsed after withdrawal of the drug. All female patients had no risk of pregnancy. Thalidomide was reintroduced and maintained at low dose (25-100 mg/day) for a minimum of 6 months. RESULTS: Eighteen patients (16 females) with mean age of 34.2 yo (16-57 y.o.) received thalidomide for 6-21 months (mean 8.5 m). The mean dose of prednisone at beginning of study was 38.3 mg/d and at the end was 9.7 mg/d (p < 0.05). Complete remission of cutaneous lesions was observed in thirteen patients (72%) and partial remission in five (28%). Side effects observed were: drowsiness in eight patients, intestinal constipation in 5, transient oliguria in 1, paresthesia of hand with normal electromyography in another one. All side effects disappeared with reduction of thalidomide dose and no patient needed to stop treatment owing to side effect. CONCLUSION: Thalidomide is a good alternative therapy to SLE patients with refractory cutaneous lesions and without any risk of pregnancy.

Adolescent↗

Clinical significance of anticardiolipin antibodies in juvenile idiopathic arthritis.

OBJECTIVE: Anticardiolipin antibodies (aCL) have been demonstrated in a large spectrum of autoimmune diseases. However, its occurrence in childhood, in particular in juvenile idiopathic arthritis (JIA), is not well established. The present study addressed the frequency and clinical significance of aCL in a group of JIA patients. METHODS: aCL (IgG and IgM isotypes), antinuclear antibodies (ANA), and rheumatoid factor (RF) were determined in 86 children with JIA (33 systemic, 31 polyarticular and 22 oligoarticular onset type). Thirty-two juvenile systemic erythematosus lupus patients (JSLE) and 52 healthy children formed the control groups. The disease activity and functional status of the JIA patients were scored to study their possible associations with the presence of aCL. RESULTS: Serum aCL levels above the normal range were detected in 28/86 JIA patients (32.5%), 12/32 JSLE patients (37.5%), and 3/52 healthy children (6%). Positive aCL levels were slightly or moderately elevated (usually below 30 GPL and 20 MPL). The presence of aCL was not associated with the presence of ANA or RF. Associations between aCL and clinical parameters, such as disease onset, duration, activity or severity could not be established. No JIA patient had vascular thrombosis, thrombocytopenia or "livedo reticularis". CONCLUSION: aCL occurred in low titers in JIA children, in a similar frequency to that observed in JSLE. No association with JIA clinical parameters or the clinical features classically linked to the antiphospholipid antibody syndrome were observed.

Adolescent↗

Detection of Plasmodium falciparum: a comparison of six cloned DNA probes.

Probes pRepHind, Rep20, p242B1-1, pPF-14, clone 26 and 34 were compared for their applicability to detect P. falciparum in field conditions. Ninety four clinical samples from patients living in the malaria endemic area of Tumaco (Pacific Coast) plus 88 from Villavicencio (Eastern Plains) were tested in "dotblot" hybridization experiments. Probes Rep20, p242B1-1, pRepHind and pPF-14 detected up to 17 pg of purified P. falciparum DNA, while clone 26 and clone 34 detected up to 425 pg DNA. Probes pPF-14, P242B1-1, pRepHind and Rep 20 exhibited comparable detection levels of parasites in infected blood samples. Sensitivity declined from 69-94% in subjects with parasitemias higher than 10.000 par./ul to 15-42% in subjects with parasitemias lower than 100 par./ul. pPF-14 and p24B1-1 showed the highest sensitivity, while clone 26 and 34 presented significantly lower sensitivities. All probes were shown to be highly specific. Detection levels are dependent on specimen treatment. Treatment consisting of serum removal, Triton X-100 lysis, Proteinase K digestion, Phenol and Chloroform extractions followed by Ethanol precipitation yielded 100% sensitivity for specimens with parasite density higher than 1,000 par./l.

Animals↗