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Biomedical subjects

F Duarte

Publications and source records attributed to F Duarte.

At least 19 recordsLinked to original sources
PubMed1991

A filter affinity transfer method for the analysis of rheumatoid factors.

Transfer of serum proteins separated by thin layer agarose electrophoresis onto nitrocellulose sheets precoated with purified human polyclonal IgG followed by revelation with enzyme-coupled anti-mu or anti-alpha antisera resulted in the specific detection of rheumatoid factors (RF) belonging to the IgM or IgA classes. Mono- or polyclonality of such RF can be evaluated from the patterns of the blots (sharp bands). In addition, their light chain type can be determined using affinity filters coated with a gamma heavy chain disease protein or with IgG Fc fragments. This simple and rapid procedure allows an easy characterization of monoclonal RF, even if they are present in minute amount amongst polyclonal RF as in certain sera from rheumatoid arthritis patients.

Antibodies, Monoclonal↗
PubMed1991

Traumatic interhemispheric subdural haematomas.

According to reports in the literature traumatic interhemispheric subdural haematomas (I.S.H.) are supposed to present acutely or subacutely with contralateral monoparesis of a lower extremity or hemiparesis or in bilateral haematomas even with paraparesis, and to need early operative evacuation. In our series of 5 cases none of them followed this "classical" clinical picture, and three of them recovered without operation. We conclude that the indication for operative evacuation depends on the clinical course and that in patients with spontaneously improving symptomatology non-surgical management under close supervision may be the better solution. Also the C.T. finding of open convexity cisterns may be possible indication for conservative management.

Adolescent↗
PubMed1991

Quantitative analysis of monoclonal immunoglobulins in serum of patients with amyotrophic lateral sclerosis.

In a prospective study, we analysed the presence of monoclonal immunoglobulin (moIg) in the serum from 30 patients with amyotrophic lateral sclerosis (ALS) and 30 matched controls using a sensitive Western blot technique. The incidence of serum moIg was 60% in the ALS group and 13.3% in the control group. Most ALS sera contained 2 or 3 monoclonal components. They were IgG (72.7%) and IgM (27.3%). These results corroborate the concept of a probable association between ALS and serum moIg.

Adolescent↗
PubMed1991

[AIDS and myopathy: report of a case and review of the literature].

Report of an unusual case of myopathy in an HIV infected patient, responsive only to the immunosuppressor drug methotrexate. The patient was a 39 year old homosexual male with no past history of HIV-related manifestations. One month prior to admission he noticed that his left thigh was swollen and painful. Two weeks later both arms became enlarged and tender. A few days before admission he noticed intermittent fever and progressive dyspnea. Upon admission, oral thrush, dyspnea and global enlargement of both arms was noted. There was no articular involvement. Fiberoptic bronchoscopy revealed Pneumocystis carinii pneumonia (PCP). Serology for HIV was positive. Tests for antinuclear antibodies were negative. Serum CPK level was 1019 IU. Capillaroscopy was compatible with vasculitis. Muscle biopsy revealed multifocal myonecrosis. PCP was successfully treated with standard doses of TMP/SMZ. Although indomethacin, prednisone and dexamethasone were administered in succession, there was relentless progression of myopathy and persistence of fever. Six days after administration of methotrexate, the patient defervesced, volume of arms and legs diminished. CPK levels returned to normal after a second course of methotrexate. Upon reduction of the dose thigh enlargement recrudesced. The patient remained asymptomatic on weekly doses of methotrexate. He died five months later of acute respiratory failure.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Fulminant tropical hepatitis--experimental reproduction.

After a review of the literature on epidemiological, serological and histopathological data concerning so-called "Amazon Black Fever" (Labrea disease), an experimental model of morphological reproduction of the disease is presented. The model is based on the probable causal synergism of Labrea hepatitis, i.e., viral injury plus protein-caloric malnutrition. Mice infected with the Oriboca arbovirus presented classic yellow-fever-like lesions of the liver, with a few malnourished animals showing the characteristic morular changes of the human disease.

Animals↗
PubMed1990

Spontaneous amyloidosis in mice with malignant neoplasms.

An outbred strain of Swiss mice carrying malignant neoplasms (48 female with mammary carcinoma, 1 male with osteosarcoma) is described with a high frequency of amyloid deposits selectively located in the ileum. Amyloid deposits were demonstrated by Congo red staining and electron microscopy. Comments are directed toward methods of amyloid detection, as well as pathogenic considerations.

Amyloidosis↗
PubMed1989

Jacalin: a new laboratory tool in immunochemistry and cellular immunology.

In recent years, a new lectin--jacalin--has raised the interest of immunologists because of its original properties with respect to human immunoglobulins and lymphocytes. Its structure and carbohydrate binding specificity are now well documented, and it can be purified easily from jackfruit seeds by ion exchange or affinity chromatography. The binding and precipitating specificities of jacalin with heavy chains of human immunoglobulins allow its use as a diagnostic (IgA subclass typing) and preparative tool (purification of IgA and IgD, removal of IgA from biologic samples and preparations). Other possible applications of jacalin's binding properties also can be envisaged. In addition, the lectin displays a mitogenic activity specific for human CD4 T-lymphocytes; consequently, the proliferative response induced by jacalin appears to represent a new and interesting assay for a functional study of CD4 cells, with obvious applications in primary and acquired, especially AIDS, immune deficiency states.

Carbohydrates↗
PubMed1988

Jacalin, the human IgA1 and IgD precipitating lectin, also binds IgA2 of both allotypes.

The lectin jacalin from jackfruit seeds shows a human IgA-subclass specificity by gel precipitation and Western blotting. However, its reactivity with IgA2 is a matter of controversy. We further studied the immunoglobulin isotype specificity of jacalin by affinity chromatography with myeloma sera and by inhibition of jacalin binding to solid-phase IgA1 by purified monoclonal immunoglobulins. The lectin proved to bind IgA2 of both allotypes with a lower apparent affinity than for IgA1 and IgD.

Antibodies, Monoclonal↗
PubMed1988

[Xanthogranuloma of the choroid plexus: a case report].

We report an unusual case of a 30-year-old man who presented blindness and raised intracranial pressure secondary to a huge lateral ventricle xanthogranuloma. Computed tomographic scanning showed a highly calcified hyperdense mass that did not enhance after contrast administration. The mass was subtotally resected via transcallosal approach. The pathogenesis of the choroid plexus xanthogranuloma is discussed.

Adult↗
PubMed1988

Isotypy of serum monoclonal immunoglobulins in human immunodeficiency virus-infected adults.

The classes, subclasses and light chain types of 78 serum monoclonal immunoglobulins (MoIg) from adult patients affected with various clinical forms of human immunodeficiency virus (HIV) infection were studied by a sensitive Western blot technique. The incidence of MoIg-containing sera was 26% in a systematic study. Most of these sera contained several (up to eight) detectable MoIg. These MoIg were IgG (91%) and IgM (9%) with a predominance of light chains of the lambda type (kappa:lambda ratio 0.6). The subclass distribution of monoclonal IgG was strikingly different from that observed in myeloma; much less IgG1 and much more IgG3 and IgG4.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Schistosomiasis of the spinal cord: tumor form. Report of a case].

A case of schistosomiasis of the spinal cord is presented. A 16 years old boy developed a progressive spinal cord compression syndrome suggesting an intramedullary tumor. At the operation a granulomatous mass of the conus and epiconus was found and partially resected. The histopathological examination showed a granulomatous reaction surrounding Schistosoma mansoni eggs. The authors review the various aspects of spinal cord schistosomiasis, particularly the tumoral or granulomatous form. A comprehensive review of the literature is made.

Adolescent↗
PubMed1987

Long lasting IgG subclass and antibacterial polysaccharide antibody deficiency after allogeneic bone marrow transplantation.

Serum IgG subclasses were measured by a competitive indirect immunoassay with monoclonal antibodies in 31 leukemic patients before and after bone marrow transplantation. Antibodies to Hemophilus influenzae type b (Hib) capsular polysaccharide were determined in 28 cases. Abnormally low or borderline subclass (mostly IgG2 and IgG4) levels were found late after transplant in 23 infected and noninfected patients. These levels persisted for as long as 25 months, in association with low or borderline IgA levels in 78% of the cases. IgG2, IgG4, and IgA often showed a parallel evolution, whereas IgG1, IgG3, and IgM often varied together in the opposite way. Class but not subclass deficiencies were more frequent in patients with graft-v-host disease (GVHD). Subclass abnormalities predominated in infected patients, with mean levels correlating with the severity of infections; however, the abnormalities are not clearly predictive of infections in individual cases. Most patients with Hib pneumonia showed virtually no IgG antibody response to Hib, and one-half of the patients had a moderate IgM and IgA response. In the whole series, many sera collected greater than 1 year after graft contained very low or undetectable antibodies. Correlation between anti-Hib antibody and IgG2 levels was significant but weak because of discrepancies that were only partially explained by the subclass distribution of the antibodies.

Antibodies, Bacterial↗
PubMed1984

Isolation of monoclonal rheumatoid factors in hypergammaglobulinemic purpura.

Rheumatoid factors were isolated for immunochemical study by a simple procedure based on immunoadsorption after dissociation of immune complexes. A monoclonal IgA that was not detectable in the patient's unseparated serum was thus demonstrated in one case of hypergammaglobulinemic purpura whereas polyclonal anti-IgG antibodies were isolated in several patients with autoimmune diseases.

Antibodies, Monoclonal↗
PubMed1983

The autonomic component in blood pressure and heart rate effects of tilting in the three-toed sloth.

1. This study attempts to elucidate unique heart and blood pressure responses seen in sloths in response to tilting by blocking autonomics with atropine, propranolol, or a combination of these. 2. Atropine produces less heart rate increase in sloths than in other mammals but blocks reflex bradycardia as expected. 3. Propranolol reduces heart rate to about the same degree as in man and completely blocks all cardiac responses to tilting, both direct and reflex. 4. Atropine slightly diminishes blood pressure responses to tilting whereas propranolol tends to augment the already marked increases.

Animals↗
PubMed1982

Ependymal astrocytoma: subependyoma or subependymal glomerate astrocytoma.

The histological study of four cases and one by electron microscopy of subependyomomas allowed us to obtain morphostructural characteristics of ependymocytes and astrocytes. Comparing these findings to those of the present day literature, we propose to name these tumours ependymal astrocytomas.

Adult↗