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Biomedical subjects

C Fuentes

Publications and source records attributed to C Fuentes.

At least 19 recordsLinked to original sources

Age influence on mononuclear phagocyte system Fc-receptor function in poststreptococcal nephritis.

The Fc-receptor function of the mononuclear phagocyte system (MPS) was examined in 41 children and adult patients, by measuring the clearance of IgG-sensitized, 51Cr-labeled erythrocytes. The Fc-receptor-mediated clearance observed in patients (mean +/- SE) was not significantly different as compared to the control group of similar age distribution. However, the immune clearance time was significantly age-correlated in both groups (acute poststreptococcal glomerulonephritis, APSGN, r = 0.39, p less than 0.05; control r = 0.63, p less than 0.01). The magnitude of the Fc-specific immune clearance and the serum creatinine were also significantly correlated (r = 0.59; p less than 0.01). Circulating immune complexes (as measured by the C1q and conglutinin ELISA) did not correlate with immune clearance, which remained stable in longitudinal studies. Age-related changes in MPS Fc-receptor function could explain, at least in part, prognostic differences between children and adult patients with APSGN.

Adolescent

Distribution of HLA histocompatibility antigens, ABO blood groups and Rh antigens in alcoholic liver disease.

The distribution of 16 antigens of the HLA-A and 15 antigens of the HLA-B series of HLA system, the blood groups ABO, and Rh antigens were studied in 40 alcoholics with cirrhosis, 18 alcoholics without cirrhosis, and in normal control subjects. The group of alcoholics with cirrhosis showed a significantly high frequency of HLA-B13 (corrected P less than 0.01) when compared with normal subjects, while the frequency of HLA-B13 was similar to normal in alcoholics without cirrhosis. On the basis of these findings, its seems that the carriers of HLA-B13 are more susceptible to liver damage caused by alcohol. Both groups of alcoholics and the normal controls had a similar distribution of ABO blood groups and Rh antigens.

ABO Blood-Group System

[The optic nerve in the cat. I. Quantitative aspects in the adult cat].

A quantitative study was carried out on the adult cat optic nerve near the eyeball by systematically measuring the perimeters of all the axons seen through the optic microscope. The main purpose of this study was to define the topographical distribution of these axons in function of their size. Statistical studies show the existence of an area of maximal concentration of large axons in crescent form situated in the temporal zone of the nerve. The neurophysiological implications are discussed.

Age Factors

[The optic nerve in the cat. II. Qualitative aspects of maturation in the adult cat].

54 healthy cats were studied. In almost all cases, two types of degenerative signs could be seen: in the primary optic pathways, but also in the posterior funiculi and the spinal-cerebellar tracts, lesions of wide-diameter axons seen by their initial demyelination, accompanied by intense neuroglial reactions, and, on the other hand, a Wallerian degeneration of smaller axons situated in the axial part of the nerve. The percentage of these abnormalities must still be evaluated. Their eventual consequences and nature are discussed.

Age Factors

Immunity to antigenically related salmonellae: effects of humoral factors on the bactericidal activity of normal and immune peritoneal exudate cells.

Immunity against Salmonella enteritidis and Listeria monocytogenes was studied by measuring in vitro the bactericidal activity of peritoneal exudate cells (PEC) of control (normal PEC) and S. typhi Ty2-immune (immune PEC) mice. Specific immune serum, anti-S. tyhphi Ty2, heat inactivated at 56 degrees C for 30 min, significantly inhibited the growth of S. enteritidis only with immune PEC. These opsonic factors had no effect upon the activity of normal PEC. That such inhibition could not be demonstrated in Listeria experiments, either with immune or normal PEC, suggests that S. enteritidis was specifically recognized, in vitro, by the thermostable opsonin anti-S. typhi Ty2 and that macrophages from immune PEC were more efficient in inhibiting bacterial growth than those from normal PEC. Thus, the interaction between macrophages and the microorganism seems to play an essential role in cell-mediated as well as humoral immunity.

Antibodies, Bacterial

[Projections of the cortical visual areas of the posterior gyrus sigmoid and the caudate nucleus in the cat].

The complex performances of the visuo-motor system entail probably an intervention of circuits connecting, the primary visual areas, to other cortical regions, specially the sensory motor cortex, and certain sub-cortical formations. For testing this hypothesis, the unilateral resection of the areas 17, 18 and 19 has been undertaken on 19 cats, with delays ranging from 8 days to 3 months after intervention. The tracing of the pathways was carried out by combining different degenerating methods in particular the Marchi reaction. Based on this, it is possible to define a compact bundle of the axons originating from the primary visual cortex and dividing into two fascicles of unequal magnitude. The slender ends in the lower part of the posterior gyrus sigmoïd; the larger one penetrates into the caudale nucleus. An ultrastructural study specifies the modalities of distribution of the axons within this nucleus.

Animals

[The Marchi reaction: ultrastructural aspects (author's transl)].

A secondary demyelination process was brought about in the optic tract by unilateral enucleation of 10 adult rats which were sacrificed at 8, 15, 20, 30 and 45 days respectively, after the intervention. The Marchi reaction, which is identifiable by the presence of granular bodies, is positive at all stages, but tends to lessen towards the 45th day. The granular bodies are inside the disintegrating myelin sheath, and gradually fill the space made available by the degenerate axoplasm. The granular bodies are at first bulky and compact before breaking up and disappearing. The remains of the myelin sheath are then resorbed. Satellite cells occur from the 15th day onwards. The interest of the Marchi reaction for the tracing of nervous pathways is confirmed by these findings.

Animals