Ex vivo evaluation of a Taylor-Couette flow, immobilized heparinase I device for clinical application.
Efficient and safe heparin anticoagulation has remained a problem for continuous renal replacement therapies and intermittent hemodialysis for patients with acute renal failure. To make heparin therapy safer for the patient with acute renal failure at high risk of bleeding, we have proposed regional heparinization of the circuit via an immobilized heparinase I filter. This study tested a device based on Taylor-Couette flow and simultaneous separation/reaction for efficacy and safety of heparin removal in a sheep model. Heparinase I was immobilized onto agarose beads via cyanogen bromide activation. The device, referred to as a vortex flow plasmapheretic reactor, consisted of two concentric cylinders, a priming volume of 45 ml, a microporous membrane for plasma separation, and an outer compartment where the immobilized heparinase I was fluidized separately from the blood cells. Manual white cell and platelet counts, hematocrit, total protein, and fibrinogen assays were performed. Heparin levels were indirectly measured via whole-blood recalcification times (WBRTs). The vortex flow plasmapheretic reactor maintained significantly higher heparin levels in the extracorporeal circuit than in the sheep (device inlet WBRTs were 1. 5 times the device outlet WBRTs) with no hemolysis. The reactor treatment did not effect any physiologically significant changes in complete blood cell counts, platelets, and protein levels for up to 2 hr of operation. Furthermore, gross necropsy and histopathology did not show any significant abnormalities in the kidney, liver, heart, brain, and spleen. (+info)
"The FSGS factor:" enrichment and in vivo effect of activity from focal segmental glomerulosclerosis plasma.
A circulating causative factor has been postulated in focal segmental glomerulosclerosis (FSGS). It has been shown that serum or plasma from some FSGS increases glomerular albumin permeability (Palb) in vitro. Palb greater than 0.5 (i.e., FS activity) is associated with recurrence after transplantation. Specimens from 15 FSGS patients were studied to document the presence of a permeability factor, to isolate this factor, to characterize its biochemical properties, and to show its effect in vivo. Total lipids were extracted by chloroform/methanol (2: 1); FS activity was absent from total lipid extract. Chylomicrons and lipoproteins were removed from the plasma with dextran sulfate, followed by sequential precipitation of proteins at 50 and 70% ammonium sulfate saturation. FS activity was retained in the 70% ammonium sulfate supernatant and exhibited a 100-fold purification. FS activity was lost after heating at 100 degrees C for 10 min or after protease digestion. Under nondenaturing conditions, electrophoresis of the FSGS 70% supernatant showed a prominent low molecular weight band that was not evident in the 70% supernatant from normal plasma. Dialysis and centrifugation-based membrane ultrafiltration of the FSGS factor indicated a molecular size between 30 and 50 kD. Injection of the 70% FSGS supernatant into rats caused a threefold increase in urine protein in collections from 6 to 24 h after injection. No increase in proteinuria occurred in rats injected with 70% supernatant from normal individuals. It is concluded that the FSGS factor is a low molecular weight protein with the potential to increase Palb in vitro and to cause proteinuria in vivo. (+info)
The natural course of hepatitis C virus infection 18 years after an epidemic outbreak of non-A, non-B hepatitis in a plasmapheresis centre.
BACKGROUND: The natural history of hepatitis C virus (HCV) infection is variable and factors determining the course of the illness are unclear. AIMS: To determine the natural course of HCV infection in a well characterised group of patients 18 years after an epidemic outbreak of non-A, non-B hepatitis at a plasmapheresis centre. METHODS: Between 1994 and 1996, 20 of 30 affected individuals were studied. HCV infection was confirmed using second and third generation ELISA test kits. HCV RNA was detected by a polymerase chain reaction (PCR) method and HCV genotyping was performed by analysing amplicons from the conserved 5'-non-translated region generated by nested PCR. Thirty two liver biopsies were carried out in 14 patients. RESULTS: HCV antibodies were detected in all subjects. Eighteen patients had abnormal liver enzymes and 17 were HCV RNA positive, all of whom were infected with genotype 1a. Ninety per cent of this cohort showed evidence of chronic HCV infection with 50% having progressive liver disease and 20% cirrhosis 18 years after acute onset of non-A, non-B hepatitis. Considerable variation in disease outcome occurred between individuals and no correlation with clinical features of the acute illness was found. CONCLUSIONS: Variability in the consequences of HCV infection in cases infected with the same virus suggests that host factors are important in determining disease outcome. The factors which determine differences in the natural history of the disease still remain to be elucidated. (+info)
Pathogenesis and treatment of HTLV-I associated myelopathy.
That HTLV-I is not a latent infection is indicated by the detection of mRNA in the peripheral blood and CNS of patients with HTLV-I infection and by the persisting humoral and cellular immune responses. Indeed the frequency of anti-HTLV CTL is extremely high. The reduction in anti-TAX CTL frequency following reduction in proviral load suggests that removal of viral antigen may result in a reduced inflammatory response at least in peripheral blood and although the clinical data should be interpreted with caution, perhaps in the CNS. Patients with more advanced disease, and possibly fixed deficits may not benefit from either anti-inflammatory or antiretroviral treatment. The patients with most to gain are those with least deficit in whom early diagnosis and treatment will depend on raising awareness of HTLV-I beyond the neurological community. Many patients with HAM first present to a urologist or gynaecologist with bladder dysfunction or may have been seen in the genitourinary clinical with impotence or positive treponemal serology, which in the older patient is often the result of childhood infection with Treponema pallidum pertenue. Investigation of these patients should include HTLV-I serology and further investigation of HTLV-I positive patients should include proviral load measurements as well as markers of inflammation. Treatments whether antiviral or anti-inflammatory should be assessed for their effect on both as well as a clinical response. (+info)
Acquired factor VIII inhibitor in a non-hemophilic patient with chronic hepatitis C viral infection.
Production of coagulation factor VIII inhibitor is rarely encountered in non-hemophilic patients. A 63-year-old Japanese male suffered from severe bleeding tendency caused by this inhibitor. Although he did not have malignancy or collagen disease, he had chronic hepatitis C virus (HCV) infection. Although HCV is known to induce production of various autoimmune antibodies, this may be the first report of a case with both acquired factor VIII inhibitor and HCV infection. (+info)
Calcinosis cutis and intestinal pseudoobstruction in a patient with adult onset Still's disease associated with recurrent relapses of disordered coagulopathy.
Adult onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown origin, characterized by a typical spiking fever, evanescent salmon-colored rash, polyarthralgia, and myalgia. Calcinosis cutis and gastrointestinal involvement have rarely been noted in AOSD. We herein describe a 54-year-old woman who demonstrated repeated disseminated intravascular coagulation (DIC), and adult respiratory distress syndrome (ARDS), associated with AOSD. The patient also revealed a remarkable degree of digital calcinosis cutis and intestinal pseudoobstruction. A connective tissue disease, such as systemic sclerosis, might have been the underlying factor in the latter two symptoms. (+info)
Systemic lupus erythematosus demonstrating serum anti-GM1 antibody, with sudden onset of drop foot as the initial presentation.
In systemic lupus erythematosus (SLE), peripheral neuropathies are relatively uncommon and rarely present as the initial symptom. We herein describe a 61-year-old woman who developed a sudden onset of drop foot, which was indistinguishable from Guillain-Barre syndrome based on the clinical symptoms alone. Antibodies against ganglioside GM1 were detected in the serum, while no antibodies to Campylobacter jejuni were observed. An electrophysiological study showed axonal impairment rather than demyelination. A pathological examination of a sural nerve biopsy specimen and further laboratory examinations suggested the observed peripheral neuropathies to have arisen due to lupus vasculitis. The serological activities of SLE responded well to treatment with corticosteroids, mizoribine and immunoadsorption therapies, however, the drop foot symptoms did not change remarkably. (+info)
Role of plasmalogens in the enhanced resistance of LDL to copper-induced oxidation after LDL apheresis.
Extracorporeal reduction of plasma low density lipoproteins (LDLs) by LDL apheresis was shown to attenuate the proatherogenic influences of LDL, such as impairment of vasodilation and increased monocyte adhesion to the endothelium. In 16 patients with familial hypercholesterolemia, we analyzed whether LDL apheresis by the heparin precipitation procedure affected the oxidative resistance of LDL. Plasma LDL cholesterol concentrations were reduced by 65% after the apheresis. The lag time of copper-mediated LDL oxidation was increased from 103 to 117 minutes (P<0.0005). The LDL contents of alpha-tocopherol and beta-carotene, as well as the ratio of monounsaturated to polyunsaturated fatty acids in LDL, were not altered. However, the LDL apheresis induced a 15% increase in the LDL contents of plasmalogen phospholipids (P<0.0005), a class of ether phospholipids that were recently shown to prevent lipid oxidation. The phosphatidylcholine (PC) to lysoPC ratio was elevated by 16% after the apheresis (P<0.0005). The percent increase in LDL plasmalogen phospholipids showed a close association with the increased lag time after apheresis (P<0.0005). The LDL plasmalogen contents of the blood samples from patients and from normolipidemic donors were also positively related to the lag time (P<0.005). In vitro loading of LDL with plasmalogen phospholipids resulted in a prolongation of the lag time and an increase in the PC/lysoPC ratio. In conclusion, the rapid rise in LDL contents of plasmalogen phospholipids most probably causes the increase in lag time after LDL apheresis. Plasmalogens appear to play an important role in the oxidation resistance of LDL in vivo. (+info)