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Biomedical subjects

G Buffaloe

Publications and source records attributed to G Buffaloe.

10 recordsLinked to original sources
PubMed1979

Extracorporeal immunoadsorption: initial experience in human systemic lupus erythematosus.

Extracorporeal immunoadsorption and filtration was used in treatment of a 29-year-old woman with severe lupus nephritis. For the previous 35 days single-stranded DNA (ssDNA) antibody and immune-complex levels had been continuously raised with only partial improvement on prednisone therapy. Levels of immune complexes and ssDNA antibodies were substantially reduced by extracorporeal plasma filtration and adsorption of DNA collodion charcoal. There were no major clinical complications. After perfusion, the reduction of ssDNA binding and immune complexes in serum was sustained, serum C'3 became normal, and serum creatinine and proteinuria improved. 28 days after perfusion, subendothelial glomerular deposits were much reduced compared with those in a pre-perfusion biopsy specimen. Selective immunoadsorption is a promising new approach to persistent lupus nephritis refractory to drug therapy alone.

Adult↗
PubMed1977

Attenuation of canine nephrotoxic glomerulonephritis with an extracorporeal immunoadsorbent.

A novel immunoadsorbent is described in which soluble canine glomerular basement membrane (GBM) antigen was immobilized in collodion membranes adherent to small charcoal particles. As much as 80% of the added GBM antigen was retained in the collodion-charcoal. The binding of GBM antibody to immobilized GBM antigen in vitro and in vivo was demonstrated. For in vivo studies, an extracorporeal circulation system was established, and mongrel dogs were then injected intravenously with GBM collodion-charcoal for 4 h. Renal tissue was examined by fluorescence and light microscopy for the deposition of heterologous gamma globulin and glomerular inflammation before and after the extracorporeal procedure. Results showed less deposition of heterologous IgG and less inflammation in experimental dog kidneys than in control kidneys. There was no evidence of release of 131I-labeled GBM from the immunoadsorbent at the conclusion of perfusion experiments and no significant biochemical or hematologic alterations. Finally, extracorporeal immunoadsorbent treatment was capable of attenuating the early heterologous phase of passive canine nephrotoxic nephritis and may have a potential role in the therapy of anti-GBM-mediated nephropathy.

Animals↗
PubMed1977

Specific removal of antibody by extracorporeal circulation over antigen immobilized in collodion-charcoal.

Studies were undertaken to determine whether BSA immobilized in collodion membranes adherent to activated charcoal particles, would be capable of specifically removing circulating BSA antibody in vitro and in vivo in an extracorporeal system in dogs. Up to 59-8 mg of BSA were retained in collodion membranes adherent to small particles. In vitro studies demonstrated that immobilized BSA could specifically reduce BSA binding activity from circulating antisera. For in vivo studies, an extracorporeal circulation system was established and arterial blood was circualted through a continuous flow celltrifuge in which plasma was separated from formed elements of the blood. Only plasma was circulated over the BSA collodion-charcoal immunoadsorbent. Anti-BSA and anti-HSA atibodies were passively infused into dogs and, after an equlibration period of 12 or 15 min, plasma was passed over the BSA collodion-charcoal immunoadsorben. Plasma exhibited a sharp reduction in BSA binding over the next 30-60 min with only slight reduction in anti-HSA binding the same period. Dogs, actively immunized to BSA and HSA, were also treated by extracorporeal plasma perfusion over BSA collodion-charcoal. A specific decline in BSA binding of sera, was again observed with minimal changes in HSA binding. A post-perfusion rebound of BSA binding was observed which reached pre-perfusion levels after 6-8 days. A second treatment during the rebound period also resulted in a specific decline in BSA binding with a similar pattern of antibody rebound. There were no significant changes in I-labelled BSA recorded on the charcoal before and after in vivo procedures and no signifcant alterations in haematocrit, serum sodium, potassium, calcium, magnesium or creatinine levels before and after the procedures. These data suggests that antigen-coated charcoal may specifically withdraw circulating antibodies in vivo with minimal release of the entrapped antigen and little alteration in the host's haematological and biochemical status.

Animals↗
PubMed1976

Degradation of circulating DNA by extracorporeal circulation over nuclease immobilized on nylon microcapsules.

Studies were undertaken to determine whether deoxyribonuclease I, (DNase I) once immobilized on activated nylon microspheres, would be capable of degrading circulating DNA in vitro and in vivo in an extracorporeal circulation system in dogs. Nylon microspheres were prepared and after gentle hydrolysis and glutaraldehyde treatment, demonstrated a retention of up to 4.73 mg of Dnase I. In vitro studies showed that DNase I immobilized on microspheres degreded a significant percentage of 125I-native DNA (nDNA) within 15 min. Mongrel dogs were injected with 125I-nDNA and a variation in initial t 1/2 in individual animals was observed. Therefore, for experimental studies, 125I-nDNA was injected and decay was recorded during a control period in which untreated microcapsules were utilized in the extracorporeal system. DNase I microspheres were then introduced into the extracorporeal circuit which resulted in an acceleration of degradation of acid precipitable 125I-nDNA. When 200 mug of unlabeled DNA with 125I-nDNA was injected, a similar augmentation of DNA degradation was noted after extracorporeal circulation over DNase I microcapsules. This effect could not be attributed to release of DNase I from the microspheres since no 131I-DNase was detected in the serum or organs of the dogs at the conclusion of the experiments. 125I-nDNA:anti-DNA complexes were passively injected into dogs and after a similar control period of circulation over untreated microcapsules. DNase I microspheres were introduced. Results showed a rapid acceleration in the degradation rate of 125I-nDNA:anti-DNA complexes precipitable with (NH4)2SO4. Extracorporeal circulation over nylon microspheres resulted in no significant alteration of the host's hematocrit or platelet count, and little residual cellular debris on the microcapsules. These data suggest that DNAase immobilized on nylon microspheres may have a potential role in the specific therapy of systemic lupus erythematosus, when it is desirable to hydrolyze DNA circulating free or in combination with antibody.

Animals↗
PubMed1976

Specific extraction of antigen in vivo by extracorporeal circulation over antibody immobilized in collodion-charcoal.

A novel extracorporeal immunoadsorbent is described in which anti-bovine serum albumin (anti-BSA) was entrapped in collodion membranes adherent to activated charcoal particles. This immunoadsorbent was capable of specifically removing circulating BSA in vitro and in vivo in an extracorporeal system in dogs. In preparation of the immunoadsorbent, up to 81.2% of added anti-BSA was retained on collodion-charcoal. In vitro circulation studies demonstrated that anti-BSA collodion-charcoal removed 812% more 125I-BSA than control colloidon-charcoal. For in vivo studies, an extracorporeal circulation system was established and arterial blood was passaged through a continuous flow celltrifuge wherein plasma which was separated from formed elements of the blood was circulated over anti-BSA and control rabbit gamma-globulin collodion-charcoal. 125I-BSA was passively infused into mongrel dogs, and plasma was then circulated over extracorpeal immunoadsorbents for 2 hr. Results showed up to 896% greater uptake of circulating 125I-BSA on the charcoal containing immobilized anti-BSA compared to control charcoal. There was no evidence of release of anti-BSA from the immunoadsorbent since 125I-anti-BSA cpm on the charcoal before and after the experiments were unchanged. In addition, there were no significant alterations in hematocrit, leukocyte counts, serum sodium, potassium, calcium, magnesium, or creatinine levels before and after in vivo procedures. These data suggest that this immunoadsorbent consisting of anti-BSA immobilized in collodion membranes adherent to charcoal particles may specifically withdraw circulating antigens in vivo with minimal release of entrapped antibodies and no significant alteration in the host hematologic and biochemical status.

Animals↗
PubMed1976

Specific removal of bovine serum albumin (BSA) antibodies in vivo by extracorporeal circulation over BSA immobilized on nylon microcapsules.

Studies were undertaken to determine whether BSA, once immobilized on activated nylon microspheres, would be capable of specifically removing circulating BSA antibody in vitro and in vivo in an extracorporeal circulation system in dogs. Nylon microspheres were prepared and, after gentle hydrolysis and glutaraldehyde treatment, demonstrated a retention of up to 34.5 mg of BSA. In vitro studies showed that BSA immobilized on microspheres removed a significant percentage of BSA-binding activity. For in vivo studies, an extracorporeal circulation system was established and mongrel dogs were then injected with anti-BSA and anti-HSA antibodies. After an equilibration period, BSA microspheres were introduced into the extracorporeal circulation system. After the insertion of BSA microcapsules, serum exhibited a sharp reduction in BSA binding over the next 15 min, with a more gradual diminution over the ensuing 60 to 90 min. There was no significant reduction in anti-HSA binding over the same time frame. This effect could not be attributed to release of BSA from the microspheres since no 125I-BSA was detected in the serum or organs of the dogs at the conclusion of the experiments. After extracorporeal circulation over nylon microspheres, there were only minimal changes in the host's hematocrit or leukocyte counts and no significant thrombotic material or cellular debris was recoverable on the capsules. These data suggest that antigen immobilized on nylon microspheres may specifically withdraw circulating antibodies in vivo with minimal release of its antigenic material and little alteration in the host's hematologic status.

Animals↗