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M Vazquez

Publications and source records attributed to M Vazquez.

At least 55 records · Page 3Linked to original sources
PubMed1994

Are the pupils of premature infants affected by intraventricular hemorrhage?

The size and reactivity to light of the pupil in infants with intraventricular hemorrhage has been variously described in the literature. These descriptions have included miosis, reactivity to light, nonreactivity to light, and anisocoria. We studied the size and light reactivity of 20 infants with intraventricular hemorrhage compared with 30 controls. Both groups displayed a mean pupil diameter in relative darkness of 3.0 to 4.0 mm at various postconceptional ages (P > .05). The age of first response to light was about 30 weeks after conception in each group (P > .05). The severity of intraventricular hemorrhage as determined by ultrasound was not related to the pupil diameter in relative darkness. In general, the pupils of neonates are not affected by intraventricular hemorrhage.

Cerebral Hemorrhage↗
PubMed1993

The Trypanosoma cruzi ribosomal P protein family: classification and antigenicity.

The multi-copy ribosomal P proteins have been identified on the ribosomes of prokaryotic and eukaryotic cells, and their antigenicity is an important feature of human Trypanosoma cruzi infection. In this review, Mariano Levin, Martin Vazquez, Dan Kaplan and Alejandro Schijman give a rational basis for the classification of these proteins, and discuss their inter-relationship.

Journal Article↗
PubMed1993

Humoral autoimmune response in Chagas' disease: Trypanosoma cruzi ribosomal antigens as immunizing agents.

Molecular expression cloning techniques have revealed that patients with chronic Chagas' heart disease (cChHD) present a strong humoral response against the cloned C-terminal portions of the four Trypanosoma cruzi ribosomal P proteins TcP1, TcP2 alpha (TcP2b), TcP2 beta (TcPJL5), and TcP0. This protein family presents several features that may be important in the immunopathology of Chagas disease. Their exposed location on the ribosome, and the amplification of their parasite-specific, Ser free C-terminal domain, generate a strong anti-parasite P response that may induce anti-P autoimmunity. Evidences indicate that the serological pattern of the anti-P response from chagasic patients may be the consequence of a chronic immunization with T. cruzi ribosomal antigens.

Amino Acid Sequence↗
PubMed1993

The chronic presence of the parasite, and anti-P autoimmunity in Chagas disease: the Trypanosoma cruzi ribosomal P proteins, and their recognition by the host immune system.

Molecular expression cloning techniques revealed that patients with the severest clinical form of Chagas disease, chronic Chagas heart disease, presented a strong humoral response against the cloned C-terminal portion of a Trypanosoma cruzi ribosomal P protein. Parasite P antigens identification led to characterize the ribosomal P protein system in T. cruzi. Their exposed location on the ribosome, and the "amplification" of their parasite specific, serine free C-terminal domain, generate a strong parasite specific anti-P response, that in certain cases may induce anti-P autoimmunity.

Amino Acid Sequence↗
PubMed1992

Evolution of the major histocompatibility complex: isolation of class II A cDNA clones from the cartilaginous fish.

Along with the T-cell receptor and immunoglobulin, the major histocompatibility complex (MHC) plays a key role in mounting immune responses to foreign antigen. To gain insights into the evolution of the MHC, class II A cDNA clones were isolated from nurse sharks, a member of the class of cartilaginous fish. Two closely related cDNA clones, which might encode allelic products, were identified; of the three amino acid substitutions found in the alpha 1 domain, two were located at positions postulated to interact with processed peptides. The deduced nurse shark MHC class II alpha chains showed conspicuous structural similarity to their mammalian counterparts. Isolation of cDNA clones encoding typical MHC class II alpha chains was unexpected since no direct evidence for T-cell-mediated immune responses has been obtained in the cartilaginous fish. The cartilaginous fish is phylogenetically the most primitive class of vertebrates from which any MHC gene has been isolated.

Amino Acid Sequence↗
PubMed1991

The risk of carcinoma in wire localization biopsies for mammographically detected clustered microcalcifications.

A total of 183 consecutive patients undergoing biopsies for unilateral microcalcifications concentrated in one or more segments of the breast in the absence of any palpable findings were analyzed to characterize their risk of cancer. Biopsy findings were benign in 86 patients (47%) and malignant in 97 (53%). Of the clinical and mammographic characteristics evaluated, an increasing number of linear microcalcifications, either without a dominant density (p = 0.014) or with a dominant density (p = 0.019) and the presence of heterogeneous microcalcifications (p = 0.055), were associated with a significantly increased risk of malignancy. Conversely a fibronodular parenchymal pattern (p = 0.008) was associated with a significantly decreased risk of malignancy. A high-risk group was identified, 95% (40/42) of whom had malignant biopsy findings, whose mammograms had more than 10 linear microcalcifications not associated with a dominant density (16/17) or at least one linear microcalcification associated with a dominant density (24/25). Conversely a low-risk group for cancer was identified, 88% (28/32) of whom had benign biopsy findings, whose mammograms had exclusively punctate microcalcifications within a fibronodular parenchymal milieu (26/30) or demonstrated some change in the configuration of the microcalcifications on the various mammographic views (10/10). For the remaining 109 patients there was an almost equal division between malignant and benign diagnoses (49% vs 51%).

Adenofibroma↗
PubMed1991

Glioneurofibroma: renaming the pediatric "gliofibroma": a neoplasm composed of Schwann cells and astrocytes.

Three children had central nervous system tumors with histologic and ultrastructural features corresponding to those of tumors previously described as "gliofibromas." These features, which include a composite appearance with glial and mesenchymal elements, with glial fibrillary acidic protein (GFAP)-containing and GFAP-immunonegative cells, diffuse S-100 immunoreactivity, and basal lamina wrapping processes of both cell types, suggest that the "mesenchymal" cells are Schwann cells, not fibroblasts. We therefore propose to rename this entity "glioneurofibroma." The clinical behavior of these lesions is uncertain but is more often indolent or benign.

Astrocytes↗
PubMed1990

Regional differences in the intranodal distribution of tumor cells.

The intranodal distribution of tumor cells was examined in 103 mesenteric and 135 axillary nodes to determine the frequency of a circumferential type of distribution and its relationship, if any, to central necrosis. Eighteen percent of the mesenteric nodes removed at surgery from patients with colon cancer contained a circumferential rim of viable tumor cells in an area corresponding wholly or in part to the normal location of the marginal sinus. In each case this rim of tumor cells surrounded a large central area of necrosis. In contrast, only one of the 135 axillary nodes removed from patients with breast cancer demonstrated this pattern. These findings suggest that by interrupting blood and lymph vessels, the circumferential spread of tumor cells underlies development of central necrosis. Previously described structural dissimilarities between mesenteric and axillary nodes may explain the striking difference in incidence of this pattern in these nodes.

Adenocarcinoma↗
PubMed1990

The fixed and dilated pupils of premature neonates.

We examined on a weekly basis the pupils of 30 preterm infants. In relative darkness (less than 10 foot-candles [ft.-c.] of illumination), the pupils measured a mean of 4.7 mm in the youngest infants (26 weeks' postconceptional age) when the corneal diameter was 7.0 mm. The pupils became progressively smaller, reaching 3.4 mm at 29 weeks' postconceptional age (P less than .001). The pupils did not constrict to the stimulating light (600 ft.-c.) until a mean of 30.6 weeks' (+/- 1 week) postconceptional age. Mydriasis should not be considered indicative of a central nervous system disorder, and a pupil unresponsive to light should not be considered suggestive of blindness until a preterm infant reaches at least 32 weeks' postconceptional age.

Aging↗