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At least 883 records · Page 49Linked to original sources
PubMed1985

[Are there mucoviscidosis specific humoral factors? 1: Properties, prevalence, preparation, formation].

In 1967 Spock et al. reported on the serum of cystic fibrosis (CF) homozygotes containing a factor altering the coordination of ciliary motion in rabbit tracheal explants. Just in 1967 Mangos et al. found sweat and saliva from CF homozygotes having an inhibitory effect on sodium reabsorption in the rat parotid gland. Since that time the existence of CF specific humoral factors was supposed. Hitherto mainly biological tests (especially tests of ciliary dyskinesia) were used to prove these factors. These tests caused different results which even were doubtful with regard to the existence of CF specific proteins. Recently it is possible to differentiate between proteins with effects of ciliary dyskinesia and a CF specific protein by means of high sensitive biochemical and immunological methods of protein distinction. In future one can expect elucidation of question related to the importance of CF protein in pathogenesis and diagnosis of cystic fibrosis.

Blood Proteins↗
PubMed1989

Metabolic response of Acylation Stimulating Protein to an oral fat load.

Acylation Stimulating Protein (ASP) is a small (mol wt 14,000), basic (pI 9.0) protein present in human plasma. When examined in vitro with normal human cultured skin fibroblasts and adipocytes, ASP appears to be the most potent stimulant of triglyceride synthesis yet described. In this study, a competitive ELISA assay for ASP has been developed using immunospecific polyclonal antibodies, and ASP levels have been measured in seven normal subjects. Following an oral fat load, a sustained significant increase in ASP occurs, whereas after an oral glucose load, ASP levels do not change significantly. These responses are entirely opposite to those of insulin, which rises sharply but transiently after an oral glucose load but is unchanged after an oral fat load. Both the fasting and peak ASP levels were significantly related to the postprandial lipemia. These data provide the first in vivo evidence that Acylation Stimulating Protein may play an important physiological role in the normal response to an oral fat load.

Adult↗
PubMed1989

Purification and characterization of acylation stimulating protein.

We have purified to homogeneity and analyzed the amino acid composition of a small (Mr 14,000), basic (pI 9.0) protein from human plasma. This has been named acylation stimulating protein (ASP) because it markedly stimulates triacylglycerol synthesis in human adipocytes. As well, it stimulates triacylglycerol synthesis in human skin fibroblasts cultured from normal individuals. Characteristic saturation curves for the cell metabolic responses to ASP were observed in both cell types with higher stimulation of oleate incorporation into triacylglycerol being observed in adipocytes. The stimulation of triacylglycerol synthesis was much greater with ASP than with insulin. Neither fatty acid binding protein nor albumin was able to mimic the ASP effect.

Adipose Tissue↗
PubMedDate not supplied

A novel bioreactor based on suspended particles of agarose-immobilized species.

Bioreactors often contain porous particles of agarose because these provide an enormous surface area (50 m2/cc gel) onto which enzymes or antibodies can be immobilized. Although many investigators claim that contact with agarose induces significant blood damage, we find that the biocompatibility of immobilized agarose is significantly improved when a novel system is used to fluidize the particles within the bioreactor vessel. We have built a prototype device that is oscillated vigorously about the axis of fluid flow. This action produces secondary flow patterns within the vessel that suspend the particles. In our model system, the bioreactor contains agarose immobilized heparinase. The system is biocompatible for 2 hours in vitro (in human blood at 37 degrees C) as follows: 1) hematocrit, white cell, and platelet counts do not change, 2) levels of plasma hemoglobin increase to 15-34 mg/dl, and 3) levels of complement component C3a increase to 0.64-1.4 micrograms/cc. We hope these studies lead to the development of a heparin removal system that can improve the safety of a variety of extracorporeal procedures. In addition, the techniques and approach used are sufficiently general to permit their extension to any immobilized species bioreactor for blood detoxification.

Biocompatible Materials↗
PubMed1985

The effect of body temperature on leukocyte kinetics during cardiopulmonary bypass.

Leukocyte kinetics were investigated in 22 patients undergoing cardiopulmonary bypass to determine the nature of the changes in the white blood cell count associated with this procedure. Both polymorphonuclear leukocytes and lymphocytes were taken up by the lung as pulmonary blood flow was lowered, but only polymorphonuclear leukocytes were taken up as blood flow was restored. The complement 3a level was increased approximately twice the control value within 2 minutes of going on bypass and remained elevated throughout the procedure. The peripheral white blood cell count doubled during the bypass procedure owing to a release of polymorphonuclear leukocytes and their precursors from the bone marrow. The increase in polymorphonuclear leukocytes was prevented by hyperthermia but reappeared quickly when the body temperature was restored to 36 degrees to 37 degrees C.

Adult↗
PubMed1985

Ex vivo model for pre-clinical evaluation of dialyzers containing new membranes.

The ex vivo model which reflects hemodialysis modulating factors during the first twenty minutes of blood membrane interaction, is applicable as a pre-clinical test for new membranes. The biocompatibility of a new cellulosic membrane (MC) proved to be superior to regenerated cellulose and comparable to synthetic membranes such as PAN regarding complement activation.

Cellulose↗
PubMed1982

Inhibition of human lymphocyte blastogenesis by C3: the role of serum in the tissue culture medium.

Preparations of the third component of human complement (C3) inhibit human lymphocyte blastogenic response to mitogens and antigens when cultured in serum-free medium or in medium supplemented with 5% autologous serum (AS). In contrast, when the culture medium was supplemented with 5% foetal calf serum (FCS), C3 failed to inhibit responses to mitogen (concanavalin A) or to antigen (streptolysin O); some FCS lots allowed stimulation rather than inhibition of the lymphocyte responses. Moreover, when lymphocytes were cultured in serum containing equal amounts of FCS and AS, no inhibition was seen. Our findings may explain previous studies which suggest that C3 enhances or has no effect on lymphocyte responses.

Antigens↗
PubMed1995

Signal transduction pathway of acylation stimulating protein: involvement of protein kinase C.

Acylation Stimulating Protein (ASP) was recently purified to homogeneity from human plasma and shown to be identical to C3adesArg. ASP stimulates triglycerides synthesis in human skin fibroblasts and primary human adipocytes. In vitro differentiation of human preadipocytes to mature fat cells results in increased expression and accumulation of ASP in the medium. These differentiated human adipocytes are also much more responsive to ASP than preadipocytes. The object of this study was to investigate the signal transduction pathway by which ASP causes triglyceride synthesis (TGS) to increase in human cultured fibroblasts and adipocytes. No evidence was found for a protein kinase A-mediated response. ASP action was consistent with a protein kinase C (PKC)-mediated pathway in that: 1) the effect of ASP on TGS was mimicked by 1-10 nM phorbol 12-myristate 13-acetate (PMA), a potent activator of PKC; (202% ASP vs. 178% PMA stimulation); 2) the effect of PMA and ASP were non-additive with respect to TGS; 3) staurosporine (50 nM) and GF109203X (bisindolymaleimide) at 1 microM, both competitive inhibitors of the ATP-binding site on PKC, inhibited both ASP and PMA stimulation of TGS (-59% and -65% for ASP and -84% and -99% for PMA, respectively); 4) Calphostin C (0.8 microM) which interacts with the regulatory domain of PKC also inhibited the ASP- and PMA-mediated stimulation of PKC (-76% +/- 11% inhibition for ASP and -99% +/- 20% inhibition for PMA), although in all cases the inhibition of PMA-stimulated triglyceride synthesis was greater; 5) ASP caused a time-dependent increase in intracellular diacylglycerol accumulation; and finally 6) stimulation by ASP caused an increase in PKC activity and a time-dependent translocation of PKC (maximal effect at 30 min) from the soluble intracellular compartment to a membrane-bound fraction (basal activity 22% in the membrane-bound fraction, ASP 54%, P < 0.05 and PMA 69% P < 0.0025). Taken together, the data are consistent with the conclusion that ASP acts to stimulate triglyceride synthesis via activation of the protein kinase C pathway.

Blood Proteins↗
PubMed1993

Immunological abnormalities in HIV-free haemophiliacs.

Since some haemophiliacs manifest profound immunodeficiency with no evidence of human immunodeficiency virus type 1 (HIV) infection, we measured the circulating immune complex (CIC) level in sera obtained from haemophiliacs and addressed the question of whether viral infection is associated directly or indirectly with enhanced CIC production. While more than 90% of HIV-positive individuals had a high level of CIC, around 60% of seronegative ones also showed CIC levels comparable to those of seropositive patients. These sera activated fresh complement in vitro. The patients infected with either HIV or Hepatitis C virus (HCV) or both showed higher frequency and concentration of serum CIC than those free of either pathogens. It is worth noting, however, that 64% of patients with no evidence of infection with HIV or HCV produced significant amounts of CIC. Among the infectious viruses examined, parvovirus is considered as one of the pathogens associated with CIC synthesis, since all the haemophiliacs including the HIV-free patients who had been supplied with heated coagulation factors for several years from birth carried antibodies to parvovirus B19. Strikingly, 60% of the children in this category were positive for CIC, suggesting the possible contribution of parvovirus infection to CIC formation.

Adolescent↗