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Biomedical subjects

G Matthes

Publications and source records attributed to G Matthes.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Exclusion chromatography for the separation of cryoprotective agents from freeze-preserved blood cells].

A method for separating low molecular cryoprotectiva from freeze-conserved erythrocyte- and thrombocyte-concentrates by exclusion chromatography has been described. A new vesicular packing material has been used. Only 25 to 30 minutes are necessary in order to separate glycerol respectively dimethylsulphoxide (DMSO) completely from the cells. 86.5% of the erythrocytes and 75.4% of the thrombocytes were recovered after the separation process.

Blood Platelets↗
PubMed1990

[Hemapheresis using vesicular plant separation materials].

The present paper deals with the separation of cells from soluble compounds of blood by means of exclusion chromatography using a recently described vesicular packing material made from the cell wall framework of the small duckweed Wolffia arrhiza. The cells of the periphere blood are hardly retarded in passing through a packing of the vesicular material and eluted as sharp peak at an elution volume which is near to 30% of the column volume. The behavior of cells is similar to that of the excluded high molecular weight plasma proteins (e.g. serumalbumin). Low molecular weight solutes (e.g. salts, glucose, urea, kreatinin), but also substances of considerable molecular weight (e.g. myoglobin and Vitamin B12) which are usually difficult to separate by dialysis from serum, are eluted at nearly 100% of the packing volume and may be separated completely from cells and high molecular weight proteins. In vitro-Tests did not show a reduced vitality of eluted blood cells.

Blood Component Removal↗
PubMed1990

[P-31 NMR studies of in vivo regeneration of preservative-induced changes in 2,3-diphosphoglycerate content of erythrocytes].

In this study, we analyzed the regeneration kinetics and the reversibility of the 2.3-DPG reduction in stored red cells after transfusion. Within 3 h after transfusion the 2.3-DPG levels raised up to 40% of the patients' prior 2.3-DPG concentration, although the 2.3-DPG content of the transfused red cells was less than 10% of before. The complete regeneration of the 2.3-DPG concentration occurred after 36 to 48 h after transfusion. There was a close correlation of the results obtained by P-31-NMR and enzymatic determination of DPG.

2,3-Diphosphoglycerate↗
PubMed1990

[Tissue preservation in the DRG].

The conservation of tissue in GDR is an example system of superregional supply with tissue transplants, which was established with the foundation of the Central Tissue Bank at the Charité in 1956 e. g. with the following arrangement of tissue banks in Leipzig and Rostock in 1966 and 1969. The concept of this tissue banks is characterized by means of decentralised production of tissue material under conditions of section and the central preparation, conservation and storage (chemical or radiation sterilization, conservation on base of freeze-drying (or freeze-storage), aseptic packing and storage by room temperature). This system allows the consistent disposal of 30 various nonvital tissue preparations. Until 1989 more than 170,000 allogeneic and xenogeneic tissue transplants have been produced in the tissue banks of country of which nearly 130,000 were used in 300 clinics.

Berlin↗
PubMed1990

[Methods for the preservation of soft tissue preparations for clinical use].

The demand for consistent supply of nonvital allogenous implants in tissue banks has the supposition for graft preservation. Besides of many logistic advantages the preservation methods are accompanied by the influence of original attributes, especially of biomechanic parameters in soft tissue preparations. A procedure of dura mater preparation, of fascia lata, tendons and skin is demonstrated which is preserving the required qualities of plasticity, softness and resistance. Biomechanic comparative investigations of other preservation procedures are done and first clinical results are demonstrated.

Dura Mater↗
PubMed1990

[Formaldehyde-fixed human varicose vein bioprosthesis with siliconized inner surface for hemodialysis. Clinical analysis of 165 transplants].

With the submitted study of 165 HVV-vessel-transplantations the marking properties like reduced immunogenity, primary athrombogenicity, form fixated vascular lumen, ability for punction, flow reduction and stability for storage were possible to prove. Few complications (thromboses, aneurysms, infections) and also low rate of revision marks the long-term progress of this bioprosthesis. It will be stated with emphasis, that the use of this vascular device is indicated, if the patient's veins for creation of an arteriovenous vascular access is not available. In long-term progress the rate of function is better in comparison with other similar or synthetic materials for prostheses.

Arteriovenous Shunt, Surgical↗
PubMed1989

[Mechanical donor plasmapheresis using the Haemonetics Ultralite plasma collection system. 1. Collection of fresh plasma].

In a clinical study altogether 449 machine donor plasmapheresis for collection of platelet poor fresh plasma were carried out using the new developed Haemonetics-Ultralite-Plasma-Collection-System. The average time of donation for 600 g of plasma amounted to 36 min. In comparison to other automated plasmapheresis-systems an effective plasma flow is recorded for the Ultralite-machine. All plasmapheresis procedures were well tolerated by the donors. The collected plasma is equivalent to the requirements for fresh frozen plasma. Complications due to the device or donors are small with 2.9% of the performed procedures.

Blood Donors↗
PubMed1989

Antioxidants for bone marrow cryopreservation.

Addition of antioxidants into the preservation solution improved the cryoprotection of human bone marrow cells. The viability was studied by the growth of GM-CFC in agar culture before and after storage at -196 degrees C. All used antioxidative drugs (selenomethionine, methionine, tocopherol, penicillin/Fe++) increased the tolerance of the stem cells to freezing and thawing and elevated the number of surviving GM-CFC up to the twofold in comparison with that of controls. More immature colony forming cells were especially protected.

Antioxidants↗
PubMed1989

[The MTT-dye test for the in vitro vitality control of fresh as opposed to cryopreserved rat pancreatic islets for syngeneic intraportal islet transplantation].

The vitality of freshly isolated and of cryopreserved (-1 degree C/min, 10% DMSO) islets of the rat pancreas was determined by means of the colorimetric MTT-test. The recover rate of vital islet cells amounted to 35% after cryopreservation. The in vitro results were confirmed by the effects after syngeneic intraportal transplantation. The transplantation of freshly isolated islets of Langerhans leads to a permanent normoglycemia in Streptozotocin diabetic rats (n = 5). Cryopreserved islets after transplantation (n = 5) led in contrary to it to no influence of the metabolism. The hepatic insulin content of livers with implanted cryopreserved islets amounted only 43% in face of livers with transplantation of freshly isolated islets. The MTT-assay allows accordingly a prompt judgement of the quality of islet allotransplants and this should make its way in the clinical practice.

Animals↗
PubMed1989

[Morphometric and histologic studies after transplantation of avital xenogenic tissues].

The reaction of subcutaneous soft tissue on xenogenic grafts was studied by means of morphometric and histological methods. Xenogenic grafts of human dura and bovine vessels were prepared with fibrin tissue adhesives and with a Lys-Pro-derivative which is an angiogenic factor in other animal models. The best results could be demonstrated in the animal group in which the Lys-Pro-derivative was used, 7, 28, and 87 d after operation.

Animals↗
PubMed1989

[Preparation and experimental studies with an allogenic tissue adhesive during the addition of a dipeptide which promotes wound healing].

The indication for application of tissue sealants in operative medicine was extended in the last years. With an allogenic fibrin adhesive system produced from coagulation plasma-fractions COHN I and cryoprecipitate an effective tissue glue system is introduced which is comparable to international known preparations. By addition of a wound healing compound to this tissue glue the revascularisation and connective tissue organisation of the wound area can be accelerated. Experimental data with this combined sealant prove the excellent sealing of the wound surfaces and an increased tension strength of the sealed wound.

Animals↗
PubMed1989

[A method for the preparation of demineralized bone matrix].

A procedure for preparation of a demineralized bone matrix (DBM) implant is demonstrated. The main steps of this method are refrigeration, milling/sieving, defatting, demineralization, freeze-drying and sterilization. These steps are standardized but also viable. Therefore this method is on the one hand international comparable on the other hand it creates the possibility for further investigations to improve the osteoinductive capacity of DBM.

Bone Matrix↗
PubMed1989

[Measuring chemiluminescence during blood preservation. 1. Spontaneous chemiluminescence].

A device for the measurement of spontaneous chemiluminescence (SCL) of biological fluids and cell suspensions according to Vladimirov (1966) description with using of contemporary equipment was constructed. Its dark impulse rate at room temperature of the photomultiplier was 1.5 s-1. The volume of measuring cell was 2 ml. An application of the device to investigate the blood during its conservation (21 days at 4 degrees C) showed an absence of the SCL of whole blood. The mean values of plasma SCL were in agreement with literature data. There were no regular changes of plasma SCL during the storage of blood indicating unsuitability of SCL for the detection of blood injury during its conservation.

Blood Preservation↗
PubMed1988

[Evaluating the success of blood transfusion with erythrocytes preserved in different ways].

In a clinical study 18 patients with an indication to polytransfusion were examined by reason of secondary anaemias in diseases of the haemopoietic system. The efficiency of transfusion on the basis of body height, body mass and sex of the patients and the blood volume resulting from it as well as the exact amount of haemoglobin provided by stored blood and the increase of HB post transfusionem connected with it were found to be the criteria for the success of a transfusion. However, selected clinical parameters (LDH, Hbe, potassium, bilirubin) were constantly checked. The following values for the average efficiency of transfusion were found 16 hours post transfusionem: in washed erythrocyte concentrate 77%; in erythrocyte concentrate c. b. c. 45%; in erythrocyte concentrate GK 36%. Therefore, special emphasis is placed on an accompanying control of haemotherapy.

Blood Preservation↗
PubMed1988

[Factors influencing the duration of function of arteriovenous vascular anastomoses in hemodialysis].

The function of an arterio-venous vascular access is influenced by vascular material, hemodynamics, blood coagulation and technique and number of punctures. By careful intraoperative handling, optimal postoperative care and treatment of the vascular access during and after hemodialysis the functional duration may be influenced effectively. The technique of puncture, the puncture cannula and the skill of the "puncture" are of great importance.

Arteriovenous Shunt, Surgical↗