Presence Of Control Serum Research Articles

Subjects with familial hypercholesterolemia are characterized by an inflammatory phenotype despite long-term intensive cholesterol lowering treatment

ObjectiveThe atherosclerotic process is driven by elevated Low-density lipoprotein (LDL)-cholesterol in combination with enhanced inflammatory responses. Several mediators participate in this complex inflammatory network including members of the tumour necrosis factor (receptor) superfamily. Familial hypercholesterolemia (FH) is associated with increased risk of developing premature atherosclerosis. Statin treatment may normalize LDL-cholesterol levels, but it is not known if the inflammatory responses are normalized in statin-treated FH patients. MethodsIn long-term statin-treated FH subjects (n = 33) and healthy controls (n = 10) the expression of tumour necrosis factor (receptor) superfamily related genes in peripheral blood mononuclear cells (PBMC) were analyzed by real-time quantitative RT-PCR. TNFα release was measured in PBMC from patients and controls by immunoassay. ResultsIn FH patients with normal LDL-cholesterol, after a median of 17 years of statin treatment, our major findings were: (i) Gene expression of CD137, LIGHT (lymphotoxins inducible expression, competes with HSV glycoprotein D for HVEM, a receptor expressed on T-lymphocytes), HVEM (Herpesvirus entry mediator), the two TNFα Receptors (TNFR1 and TNFR2), TNF related apoptosis inducing ligand (TRAIL) and CD40 were increased in PBMC from FH patients compared to controls. (ii) The release of TNFα in PBMC from FH patients, in response to LPS was increased compared to controls. (iii) PBMC from FH patients had enhanced spontaneous release of TNFα when incubated in the presence of control serum and in particular in the presence of FH serum. ConclusionDespite long-term statin therapy, an increased expression of several TNF related genes in PBMC isolated from FH patients was observed. Our findings may implicate a pathogenic role for inflammation and TNF related molecules in FH, and these findings suggest the possibility that novel treatment modalities beyond that of statins and lipid lowering drugs may be useful in FH subjects.

Effect of experimental renal failure on the pharmacokinetics of losartan in rats.

The purpose of this investigation was to determine whether the pharmacokinetics of the angiotensin II receptor antagonist losartan is altered in renal failure. Male Wistar rats were pretreated with uranyl nitrate or subjected to bilateral ureteral ligation to produce acute renal failure (ARF). Saline-injected and sham-operated rats, respectively, served as controls. Uranyl nitrate-treated rats showed significantly higher serum concentrations of losartan after oral administration and the area under the serum concentration-time curve (AUC(0-24)) of losartan increased about 3-fold compared to control rats. The systemic clearance of losartan significantly decreased from 410 +/- 254ml/h/kg in control to 177 +/- 112ml/h/kg in uranyl nitrate-treated rats. In order to investigate the mechanisms of reduced clearance of losartan associated with ARF, a hepatic microsome fraction was prepared from normal and ARF rats. No significant difference was found in the metabolism of losartan by hepatic microsomes prepared from ARF and control rats. In addition, the metabolic activity of microsomes was examined in the presence of uremic rat serum. The unbound clearance of losartan and the unbound clearance associated with the formation of EXP3174 in the presence of uremic serum were significantly lower than those in the presence of control serum. Furthermore, the metabolism of losartan was inhibited by indoxyl sulfate, a uremic toxin, in an uncompetitive manner. These results suggest that ARF is associated with reduced clearance of losartan due to the inhibition of hepatic metabolism by accumulated uremic toxin(s).

Mixed maternal-paternal lymphocyte cultures before and after immunotherapy for recurrent spontaneous abortions.

The increased reactivity of maternal lymphocytes in reciprocal mixed-maternal-paternal lymphocyte cultures (MMPLC), observed in the presence of control serum after immunotherapy, suggests that immunization with paternal lymphocytes may induce a highly significant cell mediated immune response in specifically alloactivated maternal lymphocytes. Reciprocal one-way MMPLC were set up with responding maternal or paternal lymphocytes and mitomycin C-treated stimulating lymphocytes. Cultures were set up for 6 days in the presence of 15% maternal or control serum. The degree of lymphocyte stimulation was measured by tritiated thymidine uptake. In maternal serum, after immunotherapy, a highly significant blocking effect on MMPLC was observed in both directions. The extent of the blocking effect in maternal serum and the stimulation in control serum was much higher, after immunotherapy, in two cases of abortions, as compared to cases with normal pregnancy outcome. Although the number of cases is very small, it may be that in abortions, in the presence of maternal serum, disturbances in the balance of cytokines or/and specific antibodies could have cytotoxic effects on MMPLC and down regulate, or "block" the specific response. For a possibly better utilization of the MMPLC test in the prediction of pregnancy outcome after immunotherapy, it may be important to examine specific antibodies in maternal serum, to investigate specifically induced cytokines in MMPLC and to evaluate T cell subsets in MMPLC in the presence of maternal and control serum.

Arachidonic acid metabolism in alveolar macrophages from actively sensitized guinea-pigs: Effects of sensitization and specific allergen

Arachidonic acid (AA) metabolism, including mediator release and lipid turnover, was explored in [ 3H]AA-radiolabelled alveolar macrophages obtained from guinea-pigs actively sensitized to ovalbumin (sAM) and controls (cAM). The basal and allergen-induced AA metabolism of cAM and sAM were examined in the presence and absence of homologous serum obtained from the same control or sensitized animals. Basal AA metabolism of cAM and sAM involved the release of lipoxygenase and cylooxygenase [ 3H]metabolites and free [ 3H]AA into the culture medium. However, in sAM, the production of free [ 3H]AA was significantly lower than in cAM. The allergen had no effect on the basal AA metabolism of cAM and sAM or on the metabolism of cAM and sAM cultured in the presence of control serum. In contrast, it increased the [ 3H]LTC 4-D 4 and free [ 3H]AA production of sAM cultured with sensitized serum but not those of cAM cultured with the same sensitized scrum. In sAM, the allergen effect disappeared when the sensitized serum was heated for 1 h to 56°C. Our results suggest that two factors, both induced by the active sensitization of guinea-pigs, one in the serum and one on the macrophages obtained from sensitized guinea-pigs, are required for the allergen to have an impact on the AA metabolism of alveolar macrophages in increasing the production of 5-lipoxygenase metabolites.

Albumin and transferrin synthesis are increased in H4 cells by serum from analbuminemic or nephrotic rats

The hepatic synthesis of several proteins, including both albumin and transferrin is increased in the nephrotic syndrome. While active suppression of albumin synthesis by lymphokines has been described, it has been assumed that augmentation of albumin synthesis is governed by a physical factor, plasma oncotic pressure (pi), and that this regulation is by a direct effect of pi on hepatocytes. The mechanisms have not been defined. Furthermore, experiments relying on suppression of protein synthesis may only test non-specific inhibitory effects of the experimental intervention. We tested an alternative hypothesis that a serum factor(s) present in hypooncotic states stimulates albumin synthesis. We incubated an immortalized cell line derived from rat hepatocytes (H4 cells) with serum from Nagase analbuminemic rats (NAR) and rats with passive Heymann nephritis (HN), a model of the nephrotic syndrome. Synthesis (incorporation of [35S]methionine) into both albumin and transferrin was increased significantly. The stimulatory effect of these sera was not extinguished by addition of rat or human albumin to the medium prior to or during incubation, even when pi in the incubation medium was increased to normal plasma levels by added albumin. Incorporation of [35S]methionine into albumin was 7841 +/- 394 cpm/mg cell protein using 10% NAR serum in the presence of human albumin (medium pi 26.1 +/- 0.17) versus 5149 +/- 420 cpm incorporation (P < 0.05) in the presence of control serum and in the absence of added albumin (medium pi 2.06 +/- 0.26 mm Hg, P < 0.001). The stimulatory activity was preserved following heating of serum for one hour at 60 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen metabolism of phagocytosing human polymorphonuclear leucocytes in diabetes mellitus.

Zymosan stimulated oxygen metabolism was investigated in polymorphonuclear leucocytes (PMN) from 6 diabetic patients. Oxygen uptake and superoxide production were continuously measured in the presence of autologous or control serum and non-opsonized zymosan, or in the absence of serum and preopsonized zymosan. The only significant impairment in the diabetic cells studied was a lower oxygen uptake in the presence of autologous serum. This defect was normalized by addition of control serum or by omitting the serum and stimulating with opsonized zymosan. In the absence of serum, the oxygen consumption was markedly diminished in only one subject, whereas two subjects showed a decrease of superoxide production in the presence of control serum. An inverse correlation between fasting glucose concentration and oxygen uptake could be demonstrated. However, exposure of normal PMN to hyperglycemic glucose concentration in vitro did not significantly alter their oxygen metabolism, suggesting that glucose alone could not be the only factor responsible for the impaired oxygen consumption in diabetic cells.

The effect of passive immunization with hetero and isoimmune anti-ovary antiserum on the feritlization of mouse, rat and hamster eggs.

The effect of passive immunization with hetero and isoimmune antiovary antiserum on the fertilization of mouse, rat, and hamster eggs was determined. Fertilization of the eggs could be inhibited by a single ip injection of respective antiovary antiserum obtained from rabbits. The antiovary antisera absorbed with the ovary did not prevent fertilization but antisera absorbed with the liver and kidney inhibited fertilization was not inhibited by a single ip injection of antiovary antiserum obtained from rats and mice, respectively. Fertilization in vitro of mouse eggs was low in the presence of control serum but was significantly reduced in the presence of antiserum (p less than .001).

Translocation of mRNA codons. II. Properties of an anti-translocase antibody.

A purified preparation of translocase, one of several enzymes required for protein biosynthesis, has been used to prepare a specific anti-translocase antibody. This antibody provides an extremely useful tool not only for detecting the enzyme independent of its activity, but for inhibiting the translocase-mediated reaction and, thus, protein biosynthesis. Though the antibody very rapidly inhibits elongation of the peptide chain, it fails to effect initiation, binding, or peptide bond formation, which strongly suggests that translocase is not a direct participant in these reactions. It also arrests translation of the defined tricodon AUG(U(6)) at the second codon, permitting formation only of the dipeptide, fMet-Phe, rather than the tripeptide, fMetPhe-(Phe)(2), which is formed in the presence of control serum. We have shown previously that the third codon becomes available only in the presence of translocase, thereby defining the site of action of the antibody. The antibody also has been used to demonstrate that translocase is antigenically distinct from the other proteins required for initiation and protein synthesis in E. coli.