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Biomedical subjects

A Pardo

Publications and source records attributed to A Pardo.

At least 109 records · Page 6Linked to original sources
PubMed1987

Carrageenin-stimulated peritoneal macrophages release in vitro collagenase and gelatinase.

Guinea pig macrophages were obtained by intraperitoneal injection of carrageenin, and in contrast with peritoneal cells from non-stimulated animals, release in vitro an active collagenase into the culture medium. Short time trypsin incubations and treatment of enzyme preparations with 4-APMA failed to reveal latent enzyme activity. Metallopeptidases specific for gelatin paralleled the presence of collagenase in the media of stimulated cells. Raw medium was fractionated by affinity chromatography with heparin-sepharose, collagenase activity bound to heparin sepharose while a gelatinase with an apparent molecular weight of 54,800 did not. When macrophages were grown in vitro in the presence of albumin, the gelatinase activity showed affinity for heparin and an apparent molecular weight of 113,000.

Animals↗
PubMed1987

Study of different factor VII deficiency variants in nine families from Spain.

Twenty-three patients with congenital factor VII (FVII) deficiency, belonging to 9 kindreds were studied. Immunological variants were classified according to the relationship between FVII coagulant activity (FVIIC) and the level of FVII antigen (FVIIAg), considering 3 previously described groups: VII-, VII+ and VIIR. Activation variants were determined by the reactivity pattern with three different thromboplastins. One patient was classified as VII-, 16 as VII+, and 6 as VIIR. Three patients belonging to the same kindred showed a Padua 2 FVII deficiency, and 1 patient showed a Padua 1 variant. There was no correlation between antigenic or activation variants and severity of bleeding tendency. Classical autosomal recessive mode of inheritance was observed in VII- and VII+ families. Nevertheless, a possible autosomal dominant trait was observed in VII+ kindreds.

Adult↗
PubMed1986

Collagen biosynthesis and degradation during deposit and resorptive phases of carrageenin granuloma.

Collagen metabolism was studied in both, the developing and resorptive phases of carrageenin granuloma. The rate of collagen biosynthesis relative to the rate of total protein synthesis is almost twice as high during the deposit phase compared with the resorptive phase of the same process. Total collagenolytic activity appears to be approximately the same in both, deposit and resorption stages of the granuloma. Notwithstanding, the enzyme is fully active during resorption; whereas half of this activity is in a latent form during deposit. Collagenolytic activity increased remarkably when assayed at 30 mM CaCl2 as compared to 10 or 50 mM.

Animals↗
PubMed1985

Abnormal B cell function in haemophiliacs and their relationship with factor concentrates administration.

The present study was performed to evaluate B cell function in haemophiliacs. Spontaneous and pokeweed mitogen (PWM)-induced immunoglobulin (Ig) production was determined by ELISA in the supernatants of cultured peripheral blood lymphocytes (PBL) from 14 haemophiliacs and 17 normal donors. Spontaneous IgM, IgA and IgG production was three times higher in patients than normal controls, while PWM-induced IgM, IgA and IgG production was markedly reduced in patients compared to normal donors (P less than 0.025). Allogeneic co-cultures of haemophiliacs and normal B plus T cell fractions revealed that these results are due to a defect of the patients' T cell depleted fraction. These abnormalities were not found in three patients who had received no clotting factor concentrates for at least 1 year prior to the study. Additionally, the annual amount of clotting factor concentrates received by treated patients correlates well with the enhancement of spontaneous Ig production (r = +0.688, P less than 0.02), the decrease of PWM-induced Ig secretion (r = -0.655, P less than 0.02), and the elevation of serum IgG levels (r = +0.610, P less than 0.05). These findings suggest that the administration of clotting factor concentrates play an important role in the altered B cell function in haemophiliacs.

Adult↗
PubMed1985

High prevalence of lupus anticoagulant in hemodialysis patients.

Coagulation studies were performed in 47 hemodialysis patients in order to assess abnormalities predisposing to thrombosis. A very high incidence of Lupus Anticoagulant was detected, a finding not previously described. This work is a preliminary report of this association and of its possible clinical implications.

Adult↗
PubMed1984

Ceruletide analgesia in biliary colic.

Ceruletide is a decapeptide isolated from the skin of an Australian frog. Its chemical and biologic relationship to cholecystokinin and its potent relaxant effect on the sphincter of Oddi makes it useful in biliary colic. In this double-blind placebo-controlled experiment, 60 subjects with moderate to severe pain caused by biliary colic were injected with ceruletide, 1 ng/kg iv or with an equal volume of saline solution. Pain in the right hypochondrium, referred pain, and Murphy's sign were scored before and after treatment. Data indicate that ceruletide is effective in biliary colic.

Adult↗
PubMed1983

Immunohistochemical identification of collagenase in carrageenin granuloma.

The collagenase present in experimental carrageenin granuloma in the guinea pig has been purified to homogeneity in acrylamide gel electrophoresis by a combination of ammonium sulfate salting out and affinity chromatography on Sepharose 4B--collagen-packed columns. The single protein band thus obtained was used as an antigen to obtain a monospecific antibody in heterologous conditions. Several immunodiffusion, immunoaffinity chromatography, and immunoinhibition tests of the antibody against the specific antigen and various possible serum and tissue contaminants suggested that the antibody was specifically directed against the enzyme protein collagenase. Indirect immunohistochemical staining of carrageenin granulomas, samples at different developmental phases with this specific anti-collagenase antibody, revealed that the specific antigenic protein (the enzyme collagenase) is universally present on the extracellular structures at both the collagen-deposition and the collagen-resorption stages. A hypothesis is proposed to account for these findings, namely, that the enzyme collagenase is bound to its substrate (collagen) under both normal and pathological conditions, and that the critical point of control of collagen degradation must be the activation of the collagen-bound enzyme.

Animals↗
PubMed1981

Benzene in blood and phenol in urine in monitoring benzene exposure in industry.

Determinations of benzene concentration in blood and of phenol in urine were made by head-space gas chromatography techniques on samples taken near the end of the work day from two groups of workers potentially exposed to low levels of benzene in the work-place atmosphere. Preliminary results suggest that benzene in blood is more reliable than phenol tests for assessing both exposure and uptake of benzene. Normal values of phenol in urine (10 mg/liter or less) were found in nearly all those cases in which benzene was detected in the blood.

Benzene↗
PubMed1980

Spectra of radical cations of phenothiazine derivatives in solution and solid state.

The UV and visible spectra of radical cations of several phenothiazine derivatives were studied using different solvents. The establishment of a relationship between these bands and the R2 and R10 substituents was attempted. The influence of the disolvents on the bands also was studied. The characteristic charge transfer band was observed in the solid state using diffuse reflectance spectroscopy. The R2 substituent did not appear to influence the band, while the R10 substituent influenced the band considerably, probably due to steric effects.

Cations↗
PubMed1980

What controls collagen resorption in vivo?

The local control of collagen degradation in mammals in vivo is currently considered to depend primarily on variations on the level of activity of specific collagenases. Such variations are believed to depend on three factors: a) the rate of active collagenase synthesis and/or of activation of inactive enzyme precursors; b) the action of serum and/or tissue collagenase inhibitors; and c) different combinations of both mechanisms. We suggest that another element contributing to the regulation of collagen degradation in vivo is the susceptibility of the substrate. Support for this suggestion is derived from two sources: 1) experimental data, indicating that the rate of collagen degradation depends on the genetic type of substrate, on its state of aggregation (including degree of cross-linking), and on the nature and amount of other macromolecules associated with collagen in vivo. Other experimental findings supporting our hypothesis are the universal presence of collagen-bound collagenase, the apparent greater affinity of the enzyme for the more recently synthetized substrate molecules, and the increased amounts of intact collagen that may be solubilized from some tissues undergoing massive collagen degradation, 2) analogy with currently accepted views on intracellular protein catabolism, which cannot be rejected a priori as irrelevant to the problem.

Collagen↗