Search PubMed⌕ Search

Biomedical subjects

A Acevedo

Publications and source records attributed to A Acevedo.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Antibiotic treatment for diabetic foot. Advantages of intravenous regional route as alternative for systemic route].

Diabetic angiopathy prevents adequate access of antibiotic agents to septic areas of the diabetic foot. We treated 22 such patients with antibiotics infused through a superficial vein associated to tourniquet occlusion of the limb (Group A). A control group of 47 patients, similar in age, sex and severity of diabetes received conventional systemic therapy (Group B). 45% of the patients exhibited occlusive arterial disease. Surgery was performed by the same team in both groups. Group A received regional anesthesia at the same time of the first antibiotic infusion. Group B received general or spinal anesthesia. Amputation was required in 5% of patients in Group A compared to 30% of patients in Group B (p < 0.02). Hospital stay was also significantly shorter in patients from Group A. No complications of this form of therapy were observed. Thus, regional antibiotic therapy may improve prognosis and facilitate management in patients with septic diabetic foot.

Adult↗
PubMed1990

[Prevalence of acute manifestations of pathologic gastroesophageal reflux].

We characterized the acute manifestations of gastroesophageal reflux in 46 patients attending an emergency ward. 43 were females and the mean age was 41 +/- 14. The diagnosis of G-E reflux was confirmed in all by the acid reflux test; esophagitis was present in 55% of patients submitted to endoscopy; the Bernstein test was positive in 43%. The population represents 3% of all emergency consults and 8% of gastroenterological consults. Severe epigastric pain, usually burning or constrictive and radiating to the dorsum, left hypochondrium and sternal region was the presenting form in 55% of patients. Pain was refractory to antispasmodic agents but was relieved by antacids. Dyspnea or bronchial obstruction was the main symptom in 16% of cases, heartburn in 13%, hematemesis in 6%. Among these patients a prolonged history of chronic G-E reflux was common. Surgical correction was undertaken in 6%, with some symptoms persisting in 17%.

Adult↗
PubMed1989

Characterization of a novel myeloid antigen regulated during differentiation of monocytic cells.

The monoclonal antibody HC1/6 generated against phorbol 12-myristate 13-acetate-treated U-937 cells recognizes a new cell surface antigen with a broad relative molecular mass ranging from 100 to 150 kDa. This antigen is also present on monocytes, platelets and endothelial cells and is weakly expressed by granulocytes. In contrast, it is absent from T, B and erythroblastoid cells. The antigen HC1/6 is also expressed by normal tissue macrophages in tonsil, lung and kidney, as well as in skin biopsies from pathologies such as sarcoidosis and lepromatous leprosy. The expression of the HC1/6 antigen is increased up to 5-fold when U-937 (promonocytic) and HL-60 (myelomonocytic) cell lines are stimulated with phorbol 12-myristate 13-acetate. Conversely, the expression of the HC1/6 antigen is down-regulated in monocytes upon treatment with interferon-gamma. These findings are discussed in relation with other myeloid cell surface markers.

Antibodies, Monoclonal↗
PubMed1989

Function of CD44(Pgp-1) homing receptor in human T cell precursors.

T cell precursors migrate from extrathymic hematopoietic tissues and differentiate after encountering the thymic microenvironment. We asked whether human T cell precursors express the CD44(Pgp-1/gp90HR) class of homing receptors that have been implicated in the traffic of hematopoietic cells, such as lymphocyte entry to peripheral lymphoid organs. Flow cytometry and immunoprecipitation studies demonstrate that CD7+34+, CD1-2-3-4-8-14-16-20- cells in bone marrow and thymus, which have been shown to exhibit features of T cell precursors, bear CD44. Immunohistological studies show that clusters of thymocytes in the subcapsular and the inner cortex and most medullary thymocytes are clearly CD44+, whereas the expression of CD44 is selectively downregulated in CD3- and CD3low functionally incompetent cortical thymocytes. The expression of CD44 is not restricted to T cell precursors but also occurs in thymic stroma, which bear a different molecular species of CD44. CD44-specific antibodies exert stimulatory effects on T cell precursors, a process that is dependent on stromal cells. We postulate that CD44 might be an adhesion molecule for precursor homing to thymus and that it participates in cell-to-cell interactions within the thymic environment.

Cell Movement↗
PubMed1989

[Ki-1 non-Hodgkin's lymphoma. A multihospital study of 21 cases].

The Ki-1 monoclonal antibody recognizes a specific membrane antigen of activated lymphoid cells and stains large-cell non Hodgkin's lymphomas and Hodgkin's disease. Thus, it is widely used in the diagnosis of anaplastic lymphomas. Morphologically, the Ki-1 monoclonal non Hodgkin's lymphoma are diffuse of multifocal either classical or cell anaplastic type. The clinical behaviour is similar to the rest of the high grade lymphomas, disseminated at diagnosis but may reach remission after aggressive chemotherapy. The immunophenotype showed T, B or null nature of the latter. The clinical and pathological results of our study carried out in a group of 21 cases ki-1 positive lymphomas is herewith reported.

Adolescent↗
PubMed1989

Expression of a gp33/27,000 MW activation inducer molecule (AIM) on human lymphoid tissues. Induction of cell proliferation on thymocytes and B lymphocytes by anti-AIM antibodies.

We have recently described several monoclonal antibodies (mAb) that recognize a heterodimeric structure (gp33/27,000 MW) expressed on the surface of human peripheral blood T lymphocytes upon activation with different mitogenic stimuli. Such mAb, when used in combination with submitogenic doses of phorbol ester, were capable of triggering T-cell proliferation. The antigen has been designated as activation inducer molecule (AIM). In the present study we have investigated the expression of the AIM in different lymphoid and non-lymphoid tissues. In addition, we have analysed the ability of lymphocyte subsets derived from thymus and tonsil to proliferate in response to anti-AIM mAb. The presence of AIM on subpopulations of lymphoid cells from thymus, tonsil, lymph node and spleen has been demonstrated by immunoprecipitation, flow cytometry and immunoperoxidase staining of tissue sections. By contrast, non-lymphoid cells from tissue such as brain, kidney, liver, lung or skin did not react with anti-AIM mAb. In thymus, the AIM expression was restricted to a subset of CD3+ medullary thymocytes, whereas CD1+ CD3- cortical thymocytes did not express this antigen. Nevertheless, the majority of both purified CD1- and CD3- thymocytes expressed AIM antigen after treatment with PMA. In tonsil and lymph node, a strong staining of a subset of CD3+ T lymphocytes located in the germinal centre was observed by immunohistochemical labelling with anti-AIM mAb. Certain T cells from the paracortical zone and CD19+ B lymphocytes from mantle region were also reactive. Both purified tonsillar T and B lymphocytes strongly expressed AIM after activation with PMA. The anti-AIM mAb was able to induce a strong proliferative response on purified CD1- thymocytes as well as on both purified tonsillar T and B lymphocytes in the presence of submitogenic doses of PMA. By contrast, no proliferative response was induced through the AIM in the CD3- immature thymocyte subset.

Antibodies, Monoclonal↗
PubMed1988

Comparative biochemical and tissue distribution study of four distinct CD45 antigen specificities.

Studies on the antigenic structure of the human CD45 glycoproteins using mAb have revealed the existence of four reactivity patterns defined specifically by distinct biochemical, cellular, and histochemical distributions. In addition to the two well characterized Ag specificities, CD45 and CD45R, present on the four glycoproteins (220, 205, 190, and 180 kDa) and on the 220-kDa member, respectively, we have identified two novel specificities. These have been defined by two different mAb, UCHL1 and PD7/26/16, that recognize an epitope exclusively expressed on the 180-kDa lowest molecular sized polypeptide and an epitope shared by the three higher molecular sized polypeptides (220, 205, 190 kDa) of the complex, respectively. It has been demonstrated that they are also part of the CD45 complex by immunoprecipitation, immunoblotting, and binding assays with purified CD45 molecules. Comparative analysis by flow cytometry and immunoperoxidase techniques also showed a distinct pattern of cell distribution for each specificity. The 180-kDa specificity is present on a subset of T cells but absent on B lymphocytes, whereas the 220-kDa specificity is mainly expressed by B cells and a subpopulation of T lymphocytes. On the other hand, the cell distribution of the epitope common to the three higher members is slightly different to the conventional pan-leukocyte CD45 specificity. Thus, certain CD45+ cell types such as cutaneous Langerhans' cells, sinusoidal lymph node macrophages, and a small subset of T cells in both lymph node and tonsil did not express the 220/205/190-kDa specificity. These results further support that CD45 glycoproteins constitute a very heterogeneous molecular complex with epitopes that are selectively expressed by different cell types and by T cells at different stages of maturation.

Animals↗
PubMed1988

A failure to find empirical support for Beardslee and Vaillant's prediction about alcoholism.

Recent studies have proposed that the personality pathology in alcoholics is probably a result, not a cause, of alcohol intake. Thus, 19 male alcoholic veterans were assessed to determine whether there was a positive correlation between personality pathology and lifetime amount of absolute alcohol consumed. A multiple regression analysis of the data showed that there was no evidence for a statistically significant positive correlation between the lifetime amount of absolute alcohol consumed and personality pathology. The only statistically significant correlation found was a negative correlation between personality pathology and age, a finding consistent with some other recent studies.

Adult↗
PubMed1988

Characterization of a CD11c-reactive monoclonal antibody (HC1/1) obtained by immunizing with phorbol ester differentiated U937 cells.

A mouse monoclonal antibody (HC1/1) specific for a differentiation marker of human monocytes and granulocytes has been generated by using as immunogen the monocytic cell line U937 differentiated with phorbol esters. This differentiation antigen has been characterized as the p150/95 member of the CD11 family of glycoproteins by cellular distribution studies, immunoprecipitation and competition experiments with MAb 3.9 specific for the CD11c antigen. Immuno-alkaline phosphatase staining of normal tissue sections with the HC1/1 MAb demonstrated that the CD11c antigen is a useful macrophage marker. Furthermore, the MAb HC1/1 stains specifically populations of macrophages on skin and lymph node sections from different pathologies such as Sarcoidosis, Granuloma annulare, Lepromatous leprosy and Toxoplasmosis.

Antibodies, Monoclonal↗
PubMed1986

VLA-3: a novel polypeptide association within the VLA molecular complex: cell distribution and biochemical characterization.

The family of human T cell activation-associated proteins, named VLA complex, is formed by the molecular association of cell surface glycoproteins of 210, 165, 130 and 80 kDa. In this report, we describe eight different monoclonal antibodies (HP mAb) specific for the 80-kDa polypeptide which preferentially associates with the 165-kDa member. Comparative immunoprecipitation and cell-binding studies demonstrated that the HP mAb recognize an epitope(s) on the 165/80 kDa subset different from those recognized by other anti-VLA mAb previously described. Furthermore, cellular and tissue distribution studies by flow cytometry and peroxidase staining showed that the HP reactivity pattern is different from other VLA specificities. The 165/80-kDa complex defined by HP mAb is present on human thymocytes, peripheral blood lymphocytes as well as on T, B and myelomonocytic cell lines. However, only the 80-kDa subunit was precipitated by HP mAb from activated T lymphocytes. These results suggest that the association between the 165- and 80-kDa subunits diminishes during the activation process, and that the epitopes recognized by the HP mAb are located on the 80-kDa protein. The novel polypeptide association of 165/80 kDa has been termed VLA-3.

Antibodies, Monoclonal↗
PubMed1985

[Use of the peroxidase-antiperoxidase technic in cytologic smears in pemphigus vulgaris].

The diagnosis of pemphigus is presently based on the correlation of clinical, histological, and direct and indirect immunofluorescent data. This article has presented the result of a study of cytological smears, taken from cutaneous lesions on five patients previously diagnosed as having pemphigus vulgaris, treated with the peroxidase-antiperoxidase technique which demonstrated a constant pattern of acntholitic cells surrounded by IgG. The authors belive that this means of study combines a high level of reliability and specificity with advantage of enabling the use of material that can be stored for a long time without special conditions, does not require biopsy and can supply data of great value for the diagnosis of this condition.

Evaluation Studies as Topic↗
PubMed1984

Midline "nonhealing" granuloma.

Destructive processes of the midface can occur in a wide variety of diseases. Intrinsic in consideration of these is a cluster of lesions, including Wegener's granulomatosis (WG), idiopathic midline granuloma (IMG), polymorphic reticulosis (PR), and lymphoma. Although there is still confusion as to whether the latter three represent a spectrum of the same malignant process, there is general agreement that WG is a separate entity on the basis of clinical presentation and therapeutic response. It is probable that PR is an emergent lymphoma, with the same prognostic and therapeutic features. Idiopathic midline granuloma is clinically similar to PR and lymphoma, but histologically it appears to be inflammatory in nature with no clearly definable malignant cell type present. At this point in time three diseases are best collectively referred to as midline "nonhealing" granuloma. The cases presented represent the spectrum of this enigmatic process.

Adult↗