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Biomedical subjects

G Busnach

Publications and source records attributed to G Busnach.

At least 37 records · Page 2Linked to original sources
PubMed1989

Fluorocytometric analysis of anti-HLA class 2 autoantibodies in patients with lupus nephritis.

Systemic lupus erythematosus (SLE) patients are known to produce a variety of autoantibodies (AAb), some of which may be directed against immunocompetent cells. Anti-B cell autoimmunity may encompass reactivity against HLA-class 2 molecules, which are also expressed on kidney tissue. We studied 15 patients with moderate to severe renal involvement and 5 lupus patients with no clinical renal disease, in order to detect the presence of anti-HLA class 2 AAb. Flow cytometry was employed in an inhibitory assay using patient sera, autologous cells and two anti-class 2 monoclonals, to establish the specificity of anti-B cell AAb. Seven out of 15 nephritis patients had detectable anti-class 2 AAb with an epitopic heterogeneity, as demonstrated by different degrees of inhibition on the binding of non-overlapping monoclonals. The specificity of the reaction was confirmed by the lack of inhibition of non-class 2 antibody binding. The presence of such AAb was not correlated with disease activity but with the presence of a diffuse proliferative glomerulonephritis on renal biopsy. Anti-class 2 AAb may be a marker of SLE diffuse proliferative nephritis.

Adolescent↗
PubMed1988

Apheretic treatment of severe familial hypercholesterolemia: comparison of dextran sulfate cellulose and double membrane filtration methods for low density lipoprotein removal.

The two more widely available techniques for the extracorporeal removal of low density lipoproteins (LDL), dextran sulfate cellulose column and double membrane filtration, were comparatively tested in severe familial hypercholesterolemic patients, both acutely and during a continued 3-month treatment. The selective dextran sulfate procedure removed close to 60% of LDL and 16% of high density lipoproteins (HDL) upon each apheresis, vs. 42% and 32%, respectively, in the case of the semi-selective double membrane filtration. Upon long term biweekly treatments, LDL-cholesterol (LDL-C) decreased, with the selective procedure, from a pre-treatment level of 406.0 +/- 40.7 mg/dl to a value fluctuating between 295.4 +/- 33.8 mg/dl and 116.9 +/- 22.0 mg/dl (highest vs. lowest levels) whereas, in the case of double membrane filtration, LDL-C levels ranged between 334.8 +/- 39.8 mg/dl and 192.3 +/- 49.9 mg/dl. HDL-cholesterol levels were somewhat raised, to a higher extent with dextran sulfate apheresis. The LDL/HDL-cholesterol "atherogenic ratio", decreased from a pre-treatment value of 10.27 +/- 3.04 to values ranging between 3.61 and 6.82 with dextran sulfate and between 6.70 and 7.68 with double membrane plasmapheresis.

Adult↗
PubMed1988

Alterations in the HDL system after rapid plasma cholesterol reduction by LDL-apheresis.

Changes in high density lipoprotein (HDL) subfraction structure and composition were analyzed during and after extracorporeal removal of apo B containing lipoproteins in seven familial hypercholesterolemic (FH) patients. After the apheretic procedure, carried out with dextran-sulfate-cellulose columns, the plasma levels of very low density lipoproteins (VLDL), low density lipoproteins (LDL), and HDL decreased by 72%, 50%, and 19%, respectively. The free cholesterol to esterified cholesterol ratio in plasma increased, with a 26% drop in the lecithin:cholesterol acyl transferase (LCAT) activity. In the ensuing 24 hours, VLDL, HDL, and LCAT activity approached the pretreatment levels. During this phase, possibly as a consequence of increased cholesterol esterification and exchange of cholesteryl esters for triglycerides between HDL and VLDL, HDL2a particles were detected in plasma. However, these metabolic changes did not result in clearcut modifications in the HDL2-HDL3 subfraction distribution. These findings clearly demonstrate that rapid changes in the plasma VLDL-LDL levels affect several processes involved in the HDL metabolism, but confirm that the HDL system, in spite of a considerable plasticity, displays a marked stability of the HDL2-HDL3 subfraction distribution.

Adolescent↗
PubMed1988

Selective and semiselective low-density lipoprotein apheresis in familial hypercholesterolemia.

Seven patients with familial hypercholesterolemia were treated fortnightly for 3 months by selective low-density lipoprotein apheresis with dextran-sulfate cellulose column (DSC). Subsequently, 4 of them were treated with semiselective double filtration. No cholesterol-lowering drugs were given. Plasma processed ranged from 39 to 58 ml/kg body weight/procedure. Fractional removals from plasma filtrate at the secondary treatment (adsorption or fractionation) for total cholesterol, high-density lipoprotein cholesterol, and albumin, respectively, were 0.84, 0.06, and 0.03 with DSC and 0.74, 0.47 and 0.35 with double filtration. Postapheresis reductions of total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were 57, 15, and 59% with DSC and 47,35, and 48% with double filtration. Both methods are suitable for clinical use, but with a 15-day treatment schedule, lowering circulating lipid fraction levels are maintained with DSC.

Adolescent↗
PubMed1988

Different cascade filtration operating modalities in clinical use.

Cascade filtration (CF) can be performed in either the single-pass or dead-end configuration. The distinction, as predicted by experimental models, is that solute removal is lower but constant in the former, and higher but variable with the quantity of filtrate in the latter. Moreover, unpredictable plugging reduces permeability during operation. It is therefore unclear which configuration is preferable in clinical use. In four cryo- and three macroglobulinemic patients, the data of 10 dead-end CF (QP) and 11 modified single-pass CF with high flow rate recycling plasma (QD) were compared. Both groups had similar starting values. Centrifugal primary plasma separation was performed. No exogenous reinfusions were used. Either 0.8 and 1.2 sq.m. surface secondary filters were employed. The ratio of plasma processed to patients' plasma volume was 1.1 +/- 0.3 in QP, and 0.94 +/- 0.09 in QD. The mean percentage removals of albumin, IgG and IgM respectively were 25.8 +/- 9, 32 +/- 17 and 47.5 +/- 26% in QP, 30.5 +/- 12, 40.5 +/- 19 and 48 +/- 17.5% in QD: albumin vs IgM p less than 0.025 in QP and p less than 0.02 in QD. A/G ratio increased from 1.6 +/- 0.5 to 2.06 +/- 0.6 in QP, and from 1.5 +/- 0.3 to 1.7 +/- 0.3 in QD. Plugging occurred in both groups, requiring 2.3 +/- 1.8 washouts/run in QP vs 1.5 +/- 1.2 in QD. IgM removal was comparable. Removal of albumin and IgG was slightly higher in QD. Similar performances can be obtained with either technique in clinical use, provided an adequate fractionation surface is available.

Adult↗
PubMed1987

Performance evaluation of cascade filtration with high flow rate recirculating plasma on the secondary filter.

Cascade filtration (CF) has been performed in 67 on-line procedures in 9 normolipidemic patients with paraproteinemic disorders. A modified dead-end technique has been employed, with high flow rate recirculating plasma on the plasma fractionation filter (QD recycled CF), and an albumin-rich, globulin-poor filtrate was reinfused into the patient. Postprocedure recoveries were 81 +/- 15% for albumin, 55 +/- 23% for IgM and 48% for cryocrit, with an increase in A/G ratio from 1.8 to 2.1. An improvement was observed also in antiatherogenic/atherogenic lipoproteins ratio, suggesting a possible use of this technique in the treatment of familial hypercholesterolemia. Plasma primary separation was obtained by centrifugation or by filtration, and no significant differences were observed on subsequent protein fractionation process. An albumin priming of the plasmafractionation circuit accounted for an additional 13% saving in postprocedure level. Different surface area secondary filters have been employed: with larger surfaces, larger volumes were processed without any increase in the waste volume and with reduced need for washouts, but with an additional loss of small molecules possibly due to entrapping onto the membrane.

Blood↗
PubMed1987

Prophylactic plasma exchange in burn treatment.

The first cause of death in burned patients is still sepsis. A great number of studies point out a serious immunodeficiency due to several circulating mediators. Nowadays early excision and plasma exchange appear to be the most efficient procedures in order to remove from the patient these circulating agents. Therefore in this study the authors have treated 8 patients (average age 25 years), who presented an average of total burned surface of 49%, with plasma exchange performed early after injury. The results of PMN and lymphocyte function tests showed a significant therapeutic correction of these parameters in patients treated with plasma exchange. The clinical observations agreed with the results: in 7 patients with positive outcome, no invasive infections were recorded. The positive results obtained warrant further investigation with this procedure.

Adolescent↗
PubMed1986

Efficacy of a combined treatment with plasma exchange and cytostatics in macroglobulinemia.

Monthly plasma exchange (PE) sessions have been carried out in 3 patients with advanced Waldenström macroglobulinemia, in order to reduce electrophoretic M band under 2g/100 ml. When PE was combined to low doses of cytostatics (n = 18), 3 procedures per session were required to obtain a mean 57.4 +/- 12.3% IgM reduction, from 4.2 +/- 1.2 to 1.7 +/- 0.5 g/100 ml. A mean 61.5 +/- 13.1% IgM reduction, from 5.5 +/- 1.3 to 2.1 +/- 1 g/100 ml, was obtained in 64 procedures carried out as the only therapy in 12 sessions, with 5.3 procedures requirement per monthly session. IgM percent reduction 24 hours after PE was greater with combined treatment (45 +/- 9.7 vs. 28.9 +/- 15.4%; p = 0.001). The advantage of a combined treatment is therefore either a lowered PE requirement or a tapered maintenance cytostatic dosage.

Chlorambucil↗
PubMed1983

T-suppressor cell abnormalities in type I membranoproliferative glomerulonephritis.

Twelve patients with type I membranoproliferative glomerulonephritis (MPGN) have been studied. All had normal renal function, none a nephrotic syndrome, and none was on therapy. In 7/12 serum C3 and/or C4 were low. T cell subsets were analysed with OKT monoclonal antibodies and Ts function (TsF) was studied by the Concanavalin-A Enhancement test (Con-A E) and with a new assay where native OKT8+ cell function only is explored (OKT8-DEP PWM test). OKT4/OKT8 ratio was lower than controls (p less than 0.025). TsF, as studied by the Con-A E was unchanged, while OKT8-DEP PWM test showed a marked decrease (p less than 0.005). Hypocomplementaemic patients (H), as compared with normo-complementaemic patients (N), had lower OKT4/OKT8 ratio (p less than 0.01) while TsF was unchanged in both groups. These results are consistent with a functional defect of Ts activity in type I MPGN. Increased OKT8+ cells may be a compensatory response, and hypocomplementaemia may be a marker of this defect.

Adult↗