Plasma Of Healthy Controls Research Articles

Total antioxidant response in patients with schizophrenia

There is a large amount of convincing data demonstrating that reactive oxygen species (ROS) are involved in initiation and development of many different forms of neuropsychiatric disorders. The levels of oxidants and antioxidants in schizophrenia have been evaluated. However, measurements of total antioxidant response (TAR) were not evaluated up to now. Therefore, the objectives of this study are to investigate plasma TAR levels in schizophrenia subtypes. A total of 76 patients with schizophrenia and 25 healthy volunteers were included in the study. Positive and Negative Syndrome Scale (SANS and SAPS, respectively) were applied to patients. TAR values were determined in the plasma of normal healthy controls and patients with schizophrenia. Plasma TAR levels of each schizophrenia subtype were significantly lower than healthy controls (P < 0.01 for disorganized, residual and undifferentiated subtypes and P < 0.01 for paranoid subtype). When intragroup comparisons were performed, paranoid subtype had higher plasma TAR levels compared to other subtypes (P < 0.01). Accordingly, as a whole group, patients with schizophrenia had lower plasma TAR levels compared to controls. Plasma TAR levels were significantly and negatively correlated with SANS scores, and duration of illness was evaluated but not related to other parameters. Consequently, the present study further emphasizes the growing consideration that free radical damage may have an important etiopathogenetic role on the development of schizophrenia and suggests that decreased plasma total antioxidant levels may be related to the progression of illness.

Functional assay of type I interferon in systemic lupus erythematosus plasma and association with anti–RNA binding protein autoantibodies

Peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE) have increased expression of genes typically induced by type I interferon (IFN). However, it has been difficult to identify and quantify the factors responsible for activation of the IFN pathway in SLE. To characterize these mediators, we developed an assay that measures the functional effects of plasma or serum components on the gene expression of cultured target cells. WISH epithelial cell line cells were cultured with medium, with recombinant IFNalpha, IFNbeta, or IFNgamma, or with 50% plasma from SLE patients (n = 73), rheumatoid arthritis (RA) patients (n = 19), or healthy donors (n = 30). Real-time quantitative polymerase chain reaction was used to determine WISH cell expression of IFN target genes, including PRKR, IFIT1, IFI44, MX1, and C1orf29 (preferentially induced by IFNalpha) and CXCL9 (Mig) (preferentially induced by IFNgamma). IFNalpha-regulated genes were induced by SLE plasma samples, but not by most of the RA or healthy control plasma samples. The activity in SLE plasma was inhibited >90% by anti-IFNalpha antibody, but not by anti-IFNbeta or anti-IFNgamma antibodies. The expression of each IFNalpha target gene induced by SLE plasma correlated with the expression of that gene studied ex vivo in PBMCs from the same patients and with the titer of anti-RNA binding protein (anti-RBP)-specific autoantibodies. Plasma activity paralleled PBMC expression of IFNalpha-inducible genes over time. IFNalpha in SLE plasma is a major stimulus of IFN target gene expression and is related to expression of those genes in PBMCs from SLE patients and to the titer of anti-RBP autoantibodies. These data provide additional support for the view that IFNalpha mediates immune system activation and dysregulation in SLE.

The procoagulant effects of factor V Leiden may be balanced against decreased levels of factor V and do not reflect in vivo thrombin formation in newborns

Thrombin regulation in newborns remains incompletely understood. We studied tissue factor-initiated thrombin formation in cord plasma in vitro, and the effects of Factor V(Leiden) (FVL) heterozygosity on thrombin regulation both in vitro and in vivo in newborns. Pregnant women with known thrombophilia (n=27) were enrolled in the study. Cord blood and venous blood at the age of 14 days were collected from 11 FVL heterozygous newborns (FVL-positive) and from 16 FVL-negative newborns. Prothrombin fragment F1 +2 and coagulation factors were measured. Tissue factor-initiated thrombin formation was studied in cord platelet-poor plasma (PPP) of FVL-negative and -positive newborns, and in both PPP and platelet-rich plasma (PRP) of healthy controls. The endogenous thrombin potential (ETP) in cord PPP or PRP was approximately 60% of that in adult plasma, while thrombin formation started approximately 55% and approximately 40% earlier in cord PPP and PRP, respectively. Further, in FVL-positive newborns thrombin formation started significantly earlier than in FVL-negative newborns. Exogenous activated protein C (APC) decreased ETP significantly more in cord than in adult PRP. In FVL-negative cord plasma 5 nM APC decreased ETP by 17.4+/-3.5% (mean+/-SEM) compared with only 3.5+/-3.8% in FVL-positive cord plasma (p=0.01). FVL-positive newborns showed similar levels of F1 +2 but significantly decreased levels of factorV compared with FVL-negative newborns both in cord plasma (FV 0.82+/-0.07 U/ml vs. 0.98+/- 0.05 U/ml, p=0.03) and at the age of two weeks (FV 1.15+/-0.04 U/ml vs. 1.32+/- 0.05 U/ml, p=0.03). In conclusion, newborn plasma showed more rapid thrombin formation and enhanced sensitivity to APC compared with adult plasma. FVL conveyed APC resistance and a procoagulant effect in newborn plasma. Lack of elevated F1+2 levels in FVL-positive infants, however, suggested the existence of balancing mechanisms; one could be the observed lower level of factor V in FVL heterozygous newborns.

Plasma nitrate values in patients with obsessive‐compulsive disorder

Recently there has been increasing evidence that free oxygen species may play an important role in the pathophysiology of various neuropsychiatric disorders. The present study was performed to assess the changes in plasma nitric oxide (NO) levels in patients with obsessive-compulsive disorder (OCD) compared to age- and sex-matched normal controls. Twenty-three patients with OCD and 23 healthy volunteers were included in the study. NO values were determined in the plasma of normal healthy controls and the OCD patients. Plasma nitrate levels in OCD patients were significantly higher than those in controls and were significantly and positively correlated with Yale-Brown Obsession Compulsion Scale scores but not related to age or to the duration of illness. These findings indicated a possible role of increased NO may be relevant to the pathophysiology of OCD.

Ghrelin – a modulator of depression associated eating disturbances

Aims: Appetite and eating behavior are frequently altered in psychiatric patients suffering from major depression or schizophrenia. However, little is known about the neurobiological mechanisms lying behind this phenomenon. The newly discovered gut-derived neuropeptide ghrelin simulates hunger and weight gain. Therefore, it might be involved in changes of appetite regulation during psychiatric disorders. Methods: In 22 hospitalized patients (20 depressed, 12 schizophrenic) and 24 healthy controls plasma ghrelin levels were measured and the psychometric scores on the Three Factor Eating Questionnaire (TFEQ) were assessed. Results: Neither ghrelin levels, nor TFEQ scores differed between patients suffering from depression or schizophrenia and healthy subjects. In the total group (r=0.455, corr. r²=0.138, F[4, 50]=3.007, p<0.05) and in the subgroup of depressed patients (r=0.682, corr. r²=0.427, F[1, 15]=12.163, p<0.01) TFEQ subscale 2 (disinhibition) was predicted by BMI corrected ghrelin levels, while age, gender, smoking, and medication did not show any influence. Conclusions: Ghrelin seems to be involved in appetite regulating pathways during psychiatric disorders like major depression or schizophrenia. However, its influence is not likely to be displayed as a difference between diagnostic groups. Rather, ghrelin is associated with a trait factor of eating behavior in depressed patients meaning susceptibility to eating problems.

Increased plasma levels of soluble CD40, together with the decrease of TGFβ1, as possible differential markers of Alzheimer disease

Alzheimer's disease (AD) is a progressive neurodegenerative illness and the most frequent cause of dementia in the elderly. The identification of activated microglia within neuritic plaques, coupled with the presence of numerous inflammatory proteins, suggests that inflammation is an integral part of the pathogenetic process in AD. In the present paper we have investigated the levels of circulating inflammatory mediators as potential AD biomarkers concentrating essentially on (a) soluble CD40 (sCD40), a member of the tumor necrosis factor receptor superfamily lacking the membrane-associated endodomain by alternative splicing, and (b) transforming growth factor (TGF)-β1, a cytokine deeply involved in AD and playing a protective role on CNS. Decrease of TGF-β1 in AD patients could enhance the effects of pro-inflammatory cytokines produced by activated microglia as well as the expression of factors, such as the CD40/CD40 ligand complex, by microglia and astrocytes. Total venous blood samples were obtained from 33 patients with clinical diagnosis of possible late-onset AD, 40 healthy age-matched and 11 healthy young individuals. A significant increase of sCD40 levels plasma of AD patients versus healthy controls was measured, concomitantly with a decrease in TGF-β1 concentration. These variations, however, showed no correlation with the expression of ApoE ɛ4 allele, which was determined in order to assess the different frequency of this risk factor between AD and control groups. Since no comparable modifications were detected in patients affected by Parkinson's disease or non-AD-based dementia, we propose that sCD40 and TGF-β1 plasma levels might represent possible differential biomarkers of AD, and be useful pre-mortem to support the clinical diagnosis of late-onset AD.

Measurement of the soluble angiopoietin receptor tie-2 in patients with coronary artery disease: development and application of an immunoassay.

The angiopoietin family has emerged as a group of crucial growth factors to normal angiogenesis. They are essential to the development of the mature vessel wall and interact with the endothelium via endothelial cell-specific tyrosine kinase receptors, tie-1 and tie-2. The role of the tie-2 receptor has been extensively examined in neovascularization associated with malignancy, but little is known about the role it may play in atherosclerosis, a condition whose pathophysiology also involves angiogenesis. Soluble tie-2 has been detected in the plasma of healthy controls, but this has yet to be applied to patients in the clinical setting. We developed an ELISA to detect plasma tie-2 levels and applied these to a clinical setting. The intra- and interassay coefficients of variation for the assay were 4.7% and 9.6%, respectively. We then measured levels of tie-2, vascular endothelial growth factor (VEGF), another factor associated with angiogenesis, and the soluble VEGF receptor Flt-1 (sFlt-1) in 75 patients with coronary artery disease [25 with acute myocardial infarction (AMI), 25 with acute coronary syndromes (ACS) and 25 with stable angina] and 25 healthy controls. Median [IQR, interquartile range] levels of tie-2 were significantly higher in the coronary artery disease patients (AMI 12 [10-17] ng mL-1, ACS 10 [9-14] ng mL-1, stable angina 9 [3-11] ng mL-1) when compared with the controls (7.5 [7-9] ng mL-1P = 0.004). As expected, levels of VEGF and sFlt were significantly different from those in the healthy controls (P = 0.011 and P < 0.001, respectively). Significant correlations were found between levels of tie-2 and VEGF (Spearman r = 0.59, P < 0.001), tie-2 and sFlt-1 (r = 0.45, P < 0.001) and VEGF and sFlt-1 (r = 0.56, P < 0.001) in the whole study group. We suggest that tie-2 may be potentially used as a marker of angiogenesis in atherosclerosis and may help elucidate the role of the angiopoietin/tie-2 system in atherogenesis.

The indices of endogenous oxidative and antioxidative processes in plasma from schizophrenic patients: The possible role of oxidant/antioxidant imbalance

There is great evidence in recent years that oxygen free radicals play an important role in the pathophysiology of schizophrenia. The present study was performed to assess the changes in plasma nitric oxide (NO) and thiobarbituric acid-reactive substances (TBARS) levels, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and xanthine oxidase (XO) activities in schizophrenic patients compared to age- and sex-matched normal controls. A hundred patients with schizophrenia and 51 healthy volunteers were included in the study. XO, SOD, and GSH-Px activities as well as NO and TBARS levels were estimated by standard biochemical techniques in the plasma of normal healthy controls and schizophrenia patients. In schizophrenia, increased plasma XO activity ( P<.0001) and NO levels ( P<.0001), decreased SOD activity ( P<.0001), and unchanged GSH-Px activity were detected compared to control group. Plasma TBARS levels were increased in schizophrenic patients ( P<.01), especially in the residual subtype. TBARS levels in nonsmoker schizophrenic patients were found to be higher than nonsmoker controls. Although TBARS levels in both patients and controls were found to be higher in smokers as compared to nonsmokers, it was not statistically significant. No effects of duration of the illness, gender, and low and high dose of daily neuroleptic treatment equivalent to chlorpromazine on oxidant and antioxidant parameters were observed. Because the dose and the duration of treatment with drugs have no influence on the results, it can be interpreted that the findings are more likely to be related mainly to the underlying disease. These findings indicated a possible role of increased oxidative stress and diminished enzymatic antioxidants, both of which may be relevant to the pathophysiology of schizophrenia. On the other hand, increased NO production by nitric oxide synthetases (NOSs) suggests a possible role of NO in the pathophysiological process of schizophrenia. These findings may also suggest some clues for the new treatment strategies with antioxidants and NO synthase (NOS) inhibitors in schizophrenia.

Modulation of neutrophil apoptosis by plasma and peritoneal fluid from patients with advanced endometriosis.

The increased production of pro-inflammatory chemoattractant cytokines for neutrophils in endometriosis suggests that changes in the immune system play an important role in the pathophysiology of endometriosis. The effects of plasma and peritoneal fluid from patients with advanced endometriosis on the apoptosis of neutrophils were investigated. Apoptotic changes of neutrophils were evaluated by morphological changes using Giemsa staining. Apoptosis was confirmed by DNA electrophoretic analysis. Compared with the plasma (n = 20) and peritoneal fluid (n = 5) of healthy controls, the addition of 10% plasma (n = 20) and peritoneal fluid (n = 10) from patients with endometriosis to an in-vitro culture of neutrophils from healthy subjects reduced the percentage of apoptotic cells from 65.3 +/- 6.6 to 27.2 +/- 4.6% (P < 0.001) and from 45.3 +/- 4.8 to 10.5 +/- 4.3% (P < 0.001) respectively. Neutralizing interleukin-8 antibody abrogated the delay of neutrophil apoptosis induced by peritoneal fluid, but not in the plasma of endometriosis patients. These findings show that interleukin-8 is one of the neutrophil survival factors in the peritoneal fluid of endometriosis patients and that an unidentified survival factor is also present in the plasma of patients with endometriosis.

Modulation of neutrophil apoptosis by plasma and peritoneal fluid from patients with advanced endometriosis

Objective: The effects of plasma and peritoneal fluid from patients with endometriosis on apoptosis of neutrophils were investigated.Design: Controlled basic clinical study.Materials/Methods: Neutrophils and plasma were obtained from women with endometriosis (n = 20) and healthy control donors (n = 20). Peritoneal fluid from patients with endometriosis (n = 10) and the controls (n = 5) were collected prior to laparoscopic operation. Apoptotic changes of the cells were evaluated by morphological changes using Giemsa staining. DNA electrophoretic analysis were used to confirm apoptosis.Results: Compared to the plasma of healthy controls, the addition of 10% plasma from patients with endometriosis to culture medium reduced the percentage of apoptotic cells from 65.3 ± 6.6% to 27.2 ± 4.6% in cultures of neutrophils maintained in vitro at 24 h. The addition of 10% peritoneal fluid obtained from patients with endometriosis to culture medium also inhibited the apoptosis of neutrophils compared with control group (10.5 ± 4.3% vs. 45.3 ± 4.8%). 10 ng of interleukin-8 (IL-8) in the presence of plasma from controls and endometriosis patients further delayed the spontaneous apoptosis of neutrophils. Neutralizing IL-8 antibody abrogated the delay of apoptosis of neutrophils induced by peritoneal fluid but not in the plasma of endometriosis patients. Neutrophils obtained from patients with endometriosis showed delayed apoptosis in the absence and in the presence of plasma or peritoneal fluid from either source and this delay was not abrogated by neutralizing IL-8 antibody.Conclusions: These findings show that IL-8 is one of the neutrophil survival factors in the peritoneal fluid of patients with endometriosis, which contains both pro-apoptotic and anti-apoptotic cytokines. However, our results indicate that an unidentified survival factor is present in the plasma of patients with endometriosis, and also suggest that the impairment of innate immunity, such as the delayed apoptosis of neutrophils may be related with pathogenesis of endometriosis.Supported By: No support. Objective: The effects of plasma and peritoneal fluid from patients with endometriosis on apoptosis of neutrophils were investigated. Design: Controlled basic clinical study. Materials/Methods: Neutrophils and plasma were obtained from women with endometriosis (n = 20) and healthy control donors (n = 20). Peritoneal fluid from patients with endometriosis (n = 10) and the controls (n = 5) were collected prior to laparoscopic operation. Apoptotic changes of the cells were evaluated by morphological changes using Giemsa staining. DNA electrophoretic analysis were used to confirm apoptosis. Results: Compared to the plasma of healthy controls, the addition of 10% plasma from patients with endometriosis to culture medium reduced the percentage of apoptotic cells from 65.3 ± 6.6% to 27.2 ± 4.6% in cultures of neutrophils maintained in vitro at 24 h. The addition of 10% peritoneal fluid obtained from patients with endometriosis to culture medium also inhibited the apoptosis of neutrophils compared with control group (10.5 ± 4.3% vs. 45.3 ± 4.8%). 10 ng of interleukin-8 (IL-8) in the presence of plasma from controls and endometriosis patients further delayed the spontaneous apoptosis of neutrophils. Neutralizing IL-8 antibody abrogated the delay of apoptosis of neutrophils induced by peritoneal fluid but not in the plasma of endometriosis patients. Neutrophils obtained from patients with endometriosis showed delayed apoptosis in the absence and in the presence of plasma or peritoneal fluid from either source and this delay was not abrogated by neutralizing IL-8 antibody. Conclusions: These findings show that IL-8 is one of the neutrophil survival factors in the peritoneal fluid of patients with endometriosis, which contains both pro-apoptotic and anti-apoptotic cytokines. However, our results indicate that an unidentified survival factor is present in the plasma of patients with endometriosis, and also suggest that the impairment of innate immunity, such as the delayed apoptosis of neutrophils may be related with pathogenesis of endometriosis. Supported By: No support.

Idiopathic membranous glomerulonephritis is associated with altered patterns of self-reactive IgM and IgG antibody repertoires.

Idiopathic membranous glomerulonephritis (MGN) is an immune complex nephropathy characterized by the subepithelial deposition of immunoglobulin (Ig)G. The pathogenesis of the disease remains largely unknown, but recent evidence suggests that human MGN may involve an autoimmune component. In the present study, we have analyzed the IgM and IgG antibody repertoires of patients with MGN towards self- and nonself-antigens using a technique of quantitative immunoblotting on a panel of whole human tissue or solubilized bacterial cell extracts as sources of antigens. Data were compared by means of multiparametric statistical analysis. We demonstrate that the antibody repertoires of self-reactive IgM and IgG in plasma of patients with MGN exhibit significantly altered patterns of reactivity, as compared with those of healthy controls. In contrast, multiparametric statistical analysis does not discriminate the reactivity patterns of IgM and IgG in plasma of patients and healthy controls towards nonself antigens. These observations indicate that a failure in the regulation of physiological self-reactivity is associated with immune complex nephropathy in MGN.

Detection of Epstein–Barr virus DNA in peripheral blood of paediatric patients with Hodgkin's disease by real-time polymerase chain reaction

Hodgkin's disease (HD) is commonly associated with latent Epstein–Barr virus (EBV) infection. The aim of our study was a detailed molecular analysis of the EBV status in the peripheral blood of paediatric patients with HD. Blood samples from HD patients were examined before (n=28) and after treatment (n=12). The control group consisted of 20 healthy children and 10 immunosuppressed children with primary EBV infection. EBV load in plasma and peripheral blood mononuclear cells (PBMC) were determined by real time quantitative polymerase chain reaction (RQ-PCR) as recently described. Before treatment, EBV DNA was detected in the plasma of 13/24 EBV-seropositive HD patients, whereas in plasma of healthy controls no EBV DNA was detectable (P<0.001). After treatment, no EBV genomes were found in the plasma of 6 HD patients in stable and complete remission. In contrast, 2/5 HD patients with relapse of disease were positive for EBV DNA in the plasma. In PBMCs, no differences were found in EBV load measured in HD patients before or after treatment and healthy controls. A high EBV load was found in both the plasma and PBMCs of all immunosuppressed patients with primary EBV infection. Thus, EBV DNA detection in the plasma of paediatric HD patients might be of value for non-invasive diagnostic, prognostic and follow-up tests for HD.

Is RNA in Serum Bound to Nucleoprotein Complexes?

DNA and RNA are present in normal and diseased human plasma (1)(2)(3)(4)(5)(6)(7) and in the extracellular media of eukaryotic cell cultures (8)(9). Two excellent recent reviews (10)(11) indicated that neither necrotic nor apoptotic cells may fully explain the presence of DNA in plasma. In favor of apoptosis is the finding of a DNA ladder pattern after electrophoresis. Electrophoresis of nick-translated DNA isolated from plasma of healthy controls produced autoradiographic bands at sizes equivalent to whole-number multiples (1–5×) of nucleosomal DNA (185–200 bp) (12). Nevertheless, DNA is released in a homeostatic fashion (8)(9), and newly synthesized DNA is preferentially released (9)(13)(14), suggesting that neither apoptosis nor necrosis is the sole source of this DNA. Cells not only release DNA but have specialized receptors for these nucleoprotein complexes as well. A recent study (15) showed that nucleosomes bind to the exterior of cultured mesangial cells in a receptor-mediated fashion. Competition studies demonstrated inhibition of binding by nucleosomes, 200/400-bp DNA, salmon sperm DNA, and, to a lesser extent, single-stranded DNA. DNase treatment …

Release of urokinase plasminogen activator receptor during urosepsis and endotoxemia

The urokinase receptor (uPAR; CD87) is a multifunctional molecule involved in fibrinolysis, in proteolysis, in renal tubular functions, and in migration and adhesion of inflammatory cells to the site of infection. To gain insight into systemic and local release of uPAR and into its regulation during urosepsis, which is one of the leading causes of chronic renal failure, uPAR was measured in urine and plasma of healthy human controls (N = 20), patients with culture-proven urosepsis (N = 30), and healthy human volunteers intravenously injected with endotoxin (N = 7). Patients had elevated uPAR levels in both plasma and urine. Three hours after endotoxin challenge in volunteers, there was also a significant increase of uPAR in plasma and in urine. The urine/plasma ratio for uPAR was highly elevated during urosepsis and experimental endotoxemia, suggesting local production in the kidney. Accordingly, damaged tubuli strongly expressed uPAR during pyelonephritis. Moreover, tubular epithelial cells produced uPAR in vitro, and this secretion was strongly up-regulated after stimulation with interleukin-1 beta or tumor necrosis factor-alpha. We found that uPAR is released systemically and in the urinary tract during urosepsis and experimental endotoxemia. This systemic and renal production of uPAR during pyelonephritis may play a central role in eliminating the infection and protecting renal function.

Apoptosis of vascular cells in culture and reactive oxygen species generation following exposure to plasma of septic patients

The inflammatory response that occurs in sepsis has been related to the presence of cytokines, and also other soluble factors such as fas and fas-l, which can induce apoptotic cell death of endothelial cells. Also, it can result in endothelial dysfunction, with microvascular thrombosis and activation of the coagulation cascade. These events involve the transduction of extracellular stimuli by reactive oxygen species (ROS; O2•-, H2O2) that result in activation of intracellular signaling pathways like MAPKinases. We sought to evaluate the effect of soluble factors present in plasma of septic patients in rabbit endothelial (REC) and vascular smooth muscle cells (RASM) in culture, by assaying for apoptosis with a TUNEL detection method. Also, we assessed NAD(P)H oxidase production of ROS in these plasma samples and in REC and RASM homogenates after incubation with plasma, as assessed with the lucigenin 5 μM chemiluminescence technique. Septic plasma showed ROS generation when incubated with NADPH but not with NADH (51.44 ± 21.18 and 8.90 ± 4.04 versus 7.77 ± 2.60 and 1.8 ± 0.99 cpm × 103/mg/min, NADPH and NADH versus controls, respectively; n = 5-3). When incubated with homogenates of REC or RASM in the presence of both NADH or NADPH, septic plasma caused a 2- to 3-fold increase in ROS generation versus healthy control plasma (n = 5-3). Thus, septic plasma lead to apoptosis of REC and RASM, abrogated by a SOD mimic and NAD(P)H oxidase inhibitor DPI. Intrinsic NADPH oxidase ROS production was detected in the septic plasma. It also enhanced the NAD(P)H oxidase ROS production in REC and RASM homogenates. These data suggest that in sepsis there is a possible link between ROS production and vascular cell apoptosis. Table

Transient inhibition of glucose utilization by erythrocytes during the acute stage of typhoid fever

The exact reason for hemolysis of glucose-6-phosphate dehydrogenase-deficient (G6PD) erythrocytes in patients with typhoid fever is unknown. Therefore, glucose utilization by normal and G6PD-deficient erythrocytes was measured during incubation with plasma of healthy controls as well as from patients in acute or recovery stages of typhoid fever. Glucose utilization in normal and G6PD-deficient erythrocytes significantly decreased compared to the controls when incubated with plasma of patients with acute typhoid fever, which normalized to the baseline after recovery from typhoid fever, suggesting an acquired alteration in G6PD enzyme properties by Salmonella typhi or its endotoxins.

C7E3 Fab Inhibits Low Shear Flow Modulated Platelet Adhesion to Endothelium and Surface-adsorbed Fibrinogen by Blocking Platelet GP IIb/IIIa as well as Endothelial Vitronectin Receptor

The c7E3 Fab reduces ischemic complications in patients undergoing high-risk coronary angioplasty or atherectomy. The present study investigated how c7E3 Fab inhibition of the platelet receptor glycoprotein IIb/IIIa and the endothelial vitronectin receptor affected platelet adhesion to endothelium and surface adsorbed fibrinogen under flow conditions. Platelet adhesion was examined using a stagnation point flow device with shear stress and shear rates up to 2.2 dynes/cm2 and 170 s(-1), respectively. Ex vivo adhesion was compared between two groups of patients with acute myocardial infarction (AMI) treated with angioplasty and stent implantation and a group of healthy controls. Only one AMI group received c7E3 Fab therapy. Patients in both groups were administered acetyl salicylic acid (ASA) and heparin. In AMI patients c7E3 Fab reduced platelet adhesion to adsorbed fibrinogen by 79% compared to AMI patients without c7E3 Fab treatment and by 74% compared to healthy controls. Thirty hours after termination of c7E3 Fab infusion adhesion had slightly recovered with an inhibition of 61% and 52% still present, respectively. Additionally, in vitro platelet adhesion to intact endothelium and to adsorbed fibrinogen was measured during superfusion with ADP stimulated platelet rich plasma of healthy controls to which c7E3 Fab was added at a final concentration fc of 20 microg/ml. In spite of ADP stimulation c7E3 Fab completely blocked platelet adhesion to adsorbed fibrinogen and, moreover, to intact endothelium. Preincubation of endothelial cells with c7E3 (fc = 20 [microg/ml) blocked adhesion of ADP-stimulated platelets by approximately 50%. Apart from the inhibition of platelet aggregation, c7E3 Fab added in vitro and given therapeutically in patients effectively blocks platelet adhesion to components of the injured as well as intact vessel wall under stagnation point flow conditions.

Cell-free DNA in human blood plasma: length measurements in patients with pancreatic cancer and healthy controls.

The amount of non-cell-associated DNA free in blood plasma from pancreatic cancer patients usually exceeds that from healthy donors. We have evaluated the plasma DNA by gel electrophoresis and measured the variation in length of soluble DNA fragments by electron microscopy in plasma from three patients with pancreatic cancer and from three healthy controls. Whereas electrophoresis of nick-translated DNA isolated from plasma obtained from healthy controls showed autoradiographic bands at sizes equivalent to whole-number multiples (1-5x) of nucleosomal DNA (185-200 bp), in the samples obtained from pancreatic cancer patients, stronger ladder patterns appeared. Likewise, strand length distributions of DNA (DNA-SL) in the two groups differ. The DNA-SL distribution data include 2,752 measurements made from cancer patient plasma and 3,291 for control plasma. The shortest DNA-SL measured approximately 30 nm (approximately 88 bp calculated at 0.34 nm/bp) and the largest approximately 28,000 nm (>80,000 bp), with 50% of all lengths measuring between 100 and 900 nm long. The average plasma DNA-SL in controls (311 nm; median, 273 nm) exceeded that in cancer patients (231 nm; median, 185 nm). Small excesses of DNA at approximately 63, approximately 126, approximately 189, approximately 252, and approximately 315 nm, corresponding to small multiples of lengths associated with nucleosomes, were more prominent in the cancer patient plasma than in the healthy control plasma. This study provides evidence indicating differences in non-cell-associated DNA in plasma between cancer patients and healthy controls and indicates that a significant amount of this DNA is probably derived from apoptosis in neoplastic and/or normal cells.

Binding of amyloid beta precursor protein to coagulation factor XIa in vivo may favour haemorrhagic stroke.

Hereditary cerebral haemorrhage with amyloidosis, Dutch type (HCHWA-D), caused by a mutation at codon 693 in the amyloid β precursor protein (βPP) gene, is clinically characterised by haemorrhagic strokes and dementia. The secreted forms βPP751 and βPP770 are identical to protease nexin II (PNII), which is a potent inhibitor of intrinsic blood coagulation factor XIa in vitro. We investigated the concentration of complexes between factor XIa and βPP in vivo, to search for a possible cause of the haemorrhagic strokes in HCHWA-D. In this prospectively designed study, first an enzyme-linked immunosorbent assay (ELISA) was performed with dilutions of the factor XIa-βPP complexes prepared from platelets as a standard curve. By means of this ELISA, the concentration of factor XIa-βPP complexes was measured in plasma samples. Second, plasma of 23 HCHWA-D patients and 23 healthy controls was collected, and the concentration of complexes was measured with this method. The mean concentration of factor XIa-βPP complexes in plasma of HCHWA-D patients (mean 13.73 U/ ml; SD 4.78) was significantly (P = 0.05) higher than the concentration in plasma of healthy controls (mean 11.37; SD 2.77). The differences, however, were small and there was a major overlap between the concentrations in patients and controls. In HCHWA-D mutation carriers, the concentration of factor XIa-βPP complexes was not related to age, and there was no difference between presymptomatic and symptomatic mutation carriers. From this study, it can be concluded that βPP forms complexes with factor XIa in vivo both in HCHWA-D patients and in normal controls. The concentration in HCHWA-D patients was higher. This is probably the result of diffusion of complexes from the cerebral circulation into plasma. Elevated βPP in cerebrovascular amyloid deposits is possibly a local factor contributing to the development of haemorrhagic strokes.

Plasminogen: An Important Hemostatic Parameter in Septic Patients

Previously we observed in some but not all septic patients a low plasma concentration of plasminogen. To investigate prospectively whether plasma levels of plasminogen or the ratio of plasminogen to alpha-2-antiplasmin have a prognostic value for survival from sepsis and to study the variation of other hemostatic parameters during septicemia. The study population consisted of 45 consecutive patients with septicemia, 15 non-septic patients from the same intensive care unit and 30 healthy volunteers. Plasminogen concentrations were significantly lower (p < 0.001) in plasma of septic patients (median 0,62 IU/ml range: 0.15-1,06) than in plasma of healthy controls (median 1.00 IU/ml, range: 0.75-1.10) or of non-septic intensive care patients (median 1.00 IU/ml, range: 0.82-1.08). Among the other parameters tested, plasminogen activator inhibitor (PAI-1) antigen concentration and PAI activity were similar in septic and non-septic intensive care patients, but higher than in healthy controls. Concentrations of elastase-alpha-1-protease inhibitor or of thrombin-antithrombin complexes were higher in septic patients than in non-septic intensive care patients or healthy controls. A degraded form of plasminogen of 38 kDa was detected by Western blot analysis in the plasma of septic patients, but not in plasma of non-septic intensive care patients or controls. Plasminogen alone or the ratio of plasminogen to antiplasmin were good markers for survival from septicemia. E.g. for plasminogen at a cut off of 0.65 IU/ml, sensitivity was 90.5% and specificity 66.7%, whereas for the ratio of plasminogen over antiplasmin at a cut off ratio of 0,65 IU/ml, sensitivity was 95.2% and specificity 70.8%. Plasminogen or the ratio of plasminogen to antiplasmin are sensitive markers for survival in patients with septicemia.