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Biomedical subjects

F Schooneman

Publications and source records attributed to F Schooneman.

At least 73 records · Page 4Linked to original sources
PubMed1988

Use of a new plasma separation membrane for plasma donation. Technical and biological results.

Donor safety and high-quality plasma are important assumptions for a successful plasma donation. The manual technique has two major inconveniences: It is time consuming and there are risks in the transfusion because the system is not closed. Among the available technological options, filtration has great future prospects insofar as a hemocompatible and efficient membrane can be made available and at low cost. Hemascience Travenol developed the polycarbonate membrane for the first disposable. Because of a high rate of no or very low plasma flow (5-10%), the company equipped the disposable with a new membrane: the nylon membrane. This membrane was tested according to biological and technical protocols; 39 disposables were used. The anticoagulant was acid citrate dextrose formula A. The results were good: time to collect 600 g of plasma, 34 min (only two occurrences of low flow); no problem with blocking or clotting. The main biological data show no problem with molecule activation (complement factors, coagulation factors), a good recovery of Factor VIII, and no contamination of platelets (5 +/- 2 X 10(3)/ml). No side-effects in the donor were noted. These results confirm that the Hemascience Travenol system is one of the best automatic plasmapheresis systems and could be used to separate great quantities of plasma from donors.

Filtration↗
PubMed1988

[Immunosorption of apolipoproteins B. Optimization of the method in an in vitro bench test].

The aim of the present study was to determine optimum conditions for preparation and use of immunoadsorbents for removal of apolipoprotein B from plasma. An in vitro study was carried out to optimize different chromatography parameters: linear flow rate, apo B quantity loaded, gel regeneration conditions. Specificity of removal of apo B, stability of antibody covalent linkage and possible multiple use of immunoadsorbents were assessed. No significant loss of adsorption capacity was observed after sterilization and storage of immunoadsorbents.

Apolipoproteins B↗
PubMed1988

[Evaluation of an automated system of measuring erythrocyte aggregation in dysglobulinemia treated by plasma exchange].

Characteristics of a new erythrocyte aggregameter were evaluated in 7 patients with monoclonal dysglobulinemia (5 multiple myeloma, 1 Waldenström disease, 1 CLL with monoclonal immunoglobulin) treated by plasma exchange. This apparatus measures modifications of light retro-diffused by erythrocytes suspension after shear arrest. All parameters measured: Ta, Tf, S10, gamma D, gamma S were modified after plasma exchange: either immediately after the first or after the second or third plasma exchange. These findings demonstrate the value of this new technique for evaluating red cell aggregation. These data should be completed by rheological assessment of dysglobulinemia treated by plasma exchange.

Automation↗
PubMed1988

[Erythropheresis in 4 cases of congenital hemolytic anemia].

Erythrocytapheresis was performed 6 times in 4 patients with sickle cell anemia and thalassemia. Good results were obtained, particularly in pregnant patients, no crisis being observed during pregnancy. In the other patients the painful crisis was suppressed over 4 months. The technic is very easy. The Haemonetics H 30 was used, 70% of red cell volume being removed and replaced with leukocyte-poor blood.

Adolescent↗
PubMed1988

[Treatment of systemic scleroderma using plasma exchange. A study of 19 cases].

Generalized scleroderma (GS) is associated with dysimmunity anomalies suggesting possible benefits of plasma exchange (PE) therapy. Nineteen patients with GS were treated by PE (volume of plasma exchange equivalent to 5-6% body weight and replacement by 4% human albumin), initially three times weekly, then weekly, bi-monthly and monthly (total duration 12-18 months). Clinical and paraclinical follow up was for an average of more than 2 years after the end of PE (mean number 17 per patient). Clinical results were assessed as positive and lasting in 11 cases (57.9%), two cases remaining stable and three cases worsening (one death from heart failure). The remaining three cases were failures in application of treatment (difficult venous approach). Improvement was noted in cutaneous sclerosis (62% of cases), trophic disorders (recovery in 6 of 7 cases) and articular manifestations. Vasomotor disorders were improved in only 20% of cases and visceral lesions unaltered. Results of capillaroscopy showed improvement in 5 of 11 cases. Biological values could not be correlated with either the course or the therapeutic efficacy. General tolerance to PE was good but the venous approach must be of good quality. These findings suggest the need for a randomized trial to define the place of PE in the treatment of GS.

Adult↗
PubMed1988

[Pyoderma gangrenosum: treatment with plasma exchange (4 cases)].

Four patients with pyoderma gangrenosum were treated by plasma exchange. The series included one woman (cervical localization) and three men (sural localization in 1 case, multiple trunk and facial localizations in the second case and multiple, recurrent localizations on trunk and limbs in the third case). In 2 cases another disease was associated (ulcerative colitis in 1 case and Crohn's disease in the other). Between 6 and 12 plasma exchange sessions were carried out in combination with corticotherapy (1/2 mg/kg/day). Results in 2 cases were rated as very good: progression of the disease interrupted and no further pain after the 1st plasma exchange, rapid healing of lesions (a skin graft was necessary for a lesion of hand exposing tendons). A good result was obtained in the 3rd case with interruption of progression of lesions after the 1st plasma exchange but slower relief of pain. Treatment was considered a failure in the 4th case since there was no obvious regression in lesions or pain. Three of the 4 patients had no recurrences, one patient developing recurrences on 4 occasions responding well to plasma exchange each time. Pyoderma gangrenosum is a good indication for use of plasma exchange, which limits extension of ulcerating lesions, suppresses or reduces pain and decreases esthetic prejudice.

Adolescent↗
PubMed1988

[Treatment using plasma exchange of massive acute hemolysis. 15 cases].

Fifteen patients admitted to an intensive care unit for massive acute hemolysis (MAH), defined by a free hemoglobinemia of more than 60 mumol/l, were treated by plasma exchange (PE) after a mean period following onset of 48.5 39 hours. The aim of plasma exchange therapy was to obtain early purification of hemoglobin and other substances released by red cell lysis and to prevent serious complications of MAH such as shock and RVHF or acute renal failure. Treatment by PE produced a decrease in initial hemoglobinemia of 76%, this level then remaining stable. The PE also appeared effective in the prevention and treatment of shock and RVHF, but much less so for installed acute renal failure. Comparison of results with those of a previous series of 16 patients with MAH treated by exsanguino-transfusion showed that PE was more effective, simpler to perform and less aggressive for early treatment of MAH, if rigorous conditions are applied.

Adult↗
PubMed1988

[Evaluation of cascade filtration on a test sample].

Double filtration or filtration in series can be consider as an effective means of removing proteins such as IgG, IgM, immune complexes, lipoproteins from plasma. In this study, we evaluated, using a biological and technical protocol: Kuraray (2A and 4A) and Dideco (Albusave) filters. Results were good by analysis of the sieving coefficient, but the method had 2 inconveniences: problem of slogging of the columns after filtering 2 liters and too high a reject coefficient of albumin. No effective solutions exist to avoid these two problems. Nevertheless, the filtration in series technic seems to be a good method for removing cholesterol and we have undertaken new studies to improve this system.

Blood Component Removal↗
PubMed1988

Lymphocyte proliferative responses in haemophiliac patients: relations to clinical and immunological findings.

Blood lymphocyte proliferative responses to mitogens were studied in 65 patients with haemophilia (haemophilia A: 54 patients, haemophilia B: 11 patients) in parallel with 39 male control subjects. As a group, patients with haemophilia did not demonstrate abnormal proliferative responses to phytohaemagglutinin (PHA), Concanavalin A (ConA) and pokeweed mitogen (PWM) when compared with healthy controls. When the patients were analysed according to their seropositivity for antibody to human immunodeficiency virus (HIV), those who were positive had significantly decreased PHA, ConA and PWM responses. Haemophiliac patients with T4+/T8+ ratios less than 1 had reduced proliferative responses to PHA, ConA and PWM when compared to patients with ratios greater than 1. No significant difference in mitogen responses were found when the patients were analysed according to the presence or absence of palpable lymphadenopathy. Those patients with haemophilia A who had received more than 5 x 10(4) units of factor VIII during the two years preceding the study showed no significant difference in PHA, ConA and PWM responses when compared to patients receiving less.

Adolescent↗
PubMed1986

Technical aspects of different donor plasmapheresis systems and biological results obtained in collected plasma.

Four plasmapheresis systems were comparatively studied: a centrifugation system (Haemonetics Model 50) and three filtration ones (Dideco BT 810, Organon Teknika PLASMAPUR and HemaScience Autopheresis Plasmacell). For each separator we studied the technical conditions for plasma separation, the biological characteristics of the collected plasma and the in vitro recovery of factor VIIc after preparation of cryoprecipitates. Concerning the plasma extraction rate, the HemaScience apparatus was the most efficient but values were quite similar to those obtained with the Organon Teknika machine. Contaminating cells were only found in plasma separated with the Haemonetics. Total protein and immunoglobulin levels were higher in plasma collected with the Haemonetics and HaemaScience systems. Factor VIIIc activity was comparable in plasma separated by filtration or by centrifugation while fibrinopeptide A levels were higher in plasma collected by Haemonetics. Whatever the machine, no statistical difference was observed when in vitro recovery of factor VIII was studied.

Blood Donors↗
PubMed1985

[Hemorrheological changes in 50 monoclonal dysglobulinemias treated by plasma exchange].

Rheological examinations were performed before and after plasma exchanges in 50 patients with monoclonal dysglobulinaemia. The parameters investigated were blood and plasma viscosity, erythrocyte filtrability, erythrocyte aggregation and kinetics of agglutination. The results showed reduction of blood and plasma viscosity and improvement in agglutination kinetics under plasma exchanges. Rheological examinations therefore seem to be useful to follow up blood disorders, notably the hyperviscosity syndrome. They can be performed prophylactically, leading to early plasma exchanges to prevent clinical deterioration.

Blood Viscosity↗
PubMed1985

[Immunological status of hemophiliacs: study of blood T-lymphocyte populations, serum immunoglobulins, and the prevalence of anti-LAV antibodies].

Blood T-lymphocyte subsets and serum immunoglobulin levels were studied in a group of 52 haemophiliacs (44 patients with haemophilia A and 8 patients with haemophilia B). None of the patients had AIDS or belonged to any AIDS high-risk group. Patients were exclusively treated with clotting fractions obtained from healthy volunteers in metropolitan France. As compared to a group of 52 normal donors, haemophiliacs had increased numbers of suppressor lymphocytes, which resulted in depressed helper/suppressor (H/S) ratios, and increased levels of serum IgG and IgA. 21 haemophiliacs (40,3%) had a H/S ratio less than 1.4. Among patients with haemophilia A a higher mean IgG level was found in patients presenting lymphadenopathy. Decreased mean H/S ratio and increased mean serum IgG level were found in patients receiving more than 50 000 U of factor VIII during the 2 years preceding the study. No striking difference in mean serum IgG, IgA and IgM levels was found in patients with haemophilia A when H/S ratios were higher and lower than 1.4 respectively. As AIDS and immunological abnormalities among haemophiliacs probably share a common viral origin, this study emphasize the need to discourage blood donation from donors who belong to any AIDS high-risk group, and to screen sera from the blood donor population for antibodies to LAV/HTLV III.

Acquired Immunodeficiency Syndrome↗
PubMed1983

[Plasma exchange in the treatment of Behcet's disease. Preliminary study apropos of 7 cases].

Seven patients with Behcet's syndrome were given plasma exchanges (PE). They all had severe forms, essentially ocular, which had been previously treated by steroids and/or immunosuppressors for a number of years without effect on the course of the disease. The PE was associated with classical medical therapy in all cases. Four patients had daily PE on three consecutive days. Poor results were obtained in all cases with this technique. Five patients had monthly PE and a clinical improvement was observed in 4 cases, usually with a reduction in the number of exacerbations. All therapy failed in one patient who continued to have severe exacerbations. From this short series, PE would appear to be useful in chronic forms of the disease incompletely controlled by medical therapy. In these cases, PE should be repeated. However, a longer follow-up is necessary to confirm these results.

Adult↗