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Biomedical subjects

G Matthes

Publications and source records attributed to G Matthes.

At least 19 recordsLinked to original sources
PubMed1998

Intracapillary haemoglobin oxygenation and interstitial pO2 in venous flaps: an experimental study in rats.

In order to be able to objectively evaluate capillary perfusion of venous flaps, we created arterialised venous flaps, venous flow-through flaps, and unilateral pedicled venous island flaps in the epigastric vascular system of Wistar rats and determined their oxygen supply with two different methods. Interstitial pO2 was polarographically measured with a probe placed intracutaneously in the center of the 4 x 2.5 cm flaps and continuously recorded on a connected computer. Moreover, we also noninvasively determined the oxygenation of the intracapillary haemoglobin with a micro-lightguide spectrophotometer. The statistical evaluation showed comparable results for both measurement methods: Arterialised venous flaps had a better oxygen supply with a pO2 of 16 mmHg and an Hb oxygenation of 23% than the other types of venous flaps, but they have a poorer oxygen supply than conventionally perfused flaps (pO2: 24 mmHg, Hb oxygenation: 30%). Venous flow-through flaps (pO2: 9 mmHg, Hb oxygenation: 17%) and unilateral pedicled venous island flaps had a significant better oxygen supply than skin flaps without any vascular connection. The results show that the capillary system in all types of venous flaps is reached by some of the inflowing oxygenated haemoglobin over the entire flap surface to different degrees.

Animals↗
PubMed1996

[Mechanisms of metabolic changes after in-line filtration of erythrocytes].

BACKGROUND: The reasons for the improved RBC storage after in-line filtration are not fully understood. MATERIAL AND METHODS: Red blood cell concentrates were in-line filtered and stored for 6 weeks at 4 degrees C in SAGM. Parameter 2,3-DPG, p50, density, cell electrophoresis, pH were measured. RESULTS/CONCLUSION: The obtained results may explain the metabolic findings: Cell retention (during filtration older, rigide RBC are retained in the filter- a relative increase of younger RBC); changes in RBC membrane permeability (a changed electrophoretic mobility is attributed to bound RBC membrane proteins to the filter material); blood cell depletion (a high depletion efficiency prevents toxic influences of degenerating/disintegrating WBC and PLT); release of substances from filter and blood bag material (during passage of anticoagulated blood some compounds may be released in ppm concentrations - the density of in-line filtered RBC is higher than unfiltered RBC after filtration procedure and hypothermic storage).

2,3-Diphosphoglycerate↗
PubMed1994

Improved red cell quality after erythroplasmapheresis with MCS-3P.

The cell separator MCS-3P is an apheresis system offering the flexibility to collect standardized red blood cells, plasma, and/or platelets from one donor. Two different programs were used for the red cell apheresis--RBCP (collection of one unit of red cells and two units of plasma) and RBCPS (one unit of red cells and one unit of plasma). The quality of the red cell concentrates (RCC resuspended in SAG-Mannitol) during the storage time of 42 days was measured by biochemical (ATP, 2,3-DPG, pH, free Hb, free potassium, glucose, lactose, p50, hemoglobin derivatives) and rheological (morphological index, filtration/rigidity index) parameters. The donation time with 53 donors was 20 min for 355 ml RCC-SAGM and 440 ml plasma and 7 min for 335 ml RCC-SAGM and 239 ml plasma. The donor tolerance was analogous to plateletpheresis or plasmapheresis. Twenty units of the RCC-SAGM were in-line filtered within 6 or 24 hours after donation. The results obtained for red blood cell storage are at least as good as with standard collection (free hemoglobin, free potassium, glucose, lactose, hemolysis) or better (ATP, 2,3-DPG, p50, hemoglobin derivatives, filtration/rigidity index) owing to prevention of collection lesion. All blood preparations were sterile after storage (red cells 42 days, plasma after freezing). The erythroplasmapheresis with MCS-3P can be especially recommended for application in an autologous blood program because the application of autologous blood donation in hospitals is often limited by the preconditions of component separation. The erythroplasmapheresis data with MCS-3P are encouraging for the development of a new blood collection methodology.

Blood Component Removal↗
PubMed1994

[In-line-filtration of erythrocyte concentrates using the Sepacell Integra System].

Using the Sepacell Integra System for in-line filtration of red cell concentrates in additive solution the leukocyte depletion was efficient enough to keep leukocyte contamination below the critical immunogenic load for leukocytes (CILL). The data indicate improved storage conditions, made evident by significantly lower cell damage.

Cytapheresis↗
PubMed1994

[4-Log leukocyte depletion of erythrocyte concentrates--a comparison with 3 other filters].

Whole blood (WB) and SAGM-resuspended red cell concentrates (RCC) were leucocyte-depleted 1 h after donation by filtration using BF 4 (PALL), Sepacell RS 200 (Asahi Med.) and Bio R01 Plus (Biotrans). We compared the handling of the filter system, focusing routine blood bank practice, filtration efficiency [residual white cell count; flow cytometry (Ortho Cytoron) and Nageotte chamber] and the loss of red cells. Spontaneous filling was found to be an advantage of the Bio R01 Plus system, whereas the BPF 4 and the RS 200 have to be filled by pressure. The filtrations were of similar duration, even those of WB and resuspended RCC. Red cell loss was found to be 10-15% on RCC higher than on WB (7-10%) and varied between the filters used: BPF 4 < Bio R01 Plus < RS 200. The residual white cell count on WB was 1.2-5.8 x 10(6) (RS 200 < Bio R01 Plus < BPF 4) and on RCC was 0.5-3.0 x 10(5) (RS 200 < BPF 4 < Bio R01 Plus). The filters used are highly effective (4-log depletion on RCC) even on fresh WB and are therefore potential in-line filters.

Blood Donors↗
PubMed1994

[In-line-filtration of erythrocyte concentrates using the Leukotrap-RC system].

'In-line filtration' was performed on whole blood (WB) of 12 healthy donors. The WB was drawn into the triple-bag Leukotrap-RC system. Six red cell concentrates (RCC) were filtrated 1 h after donation either with or without buffy-coat and stored 35 days in AS-3. We measured the loss of red cells, the residual white cell count (Nageotte chamber), platelet count in fresh frozen plasma (FFP); 2,3-DPG, K+, Hbe, pH, O2Hb and pO50. The system was easy to handle but needed circular centrifugation holders because the filter is placed and fixed just at the top of the bags during centrifugation. RCC without buffy coat led to a faster filtration (15 vs, 38 min) and to an improved FFP quality (platelet count 23 vs, 54 Gpt/l). The leucocyte removal rate of the integrated PALL-RC-350 was similar, residual white cell count less than 3 x 10(6), in both preparations. All storage parameters were found within the normal range except a significant increase of O2Hb in filtrated red cells compared with the unfiltered control.

Blood Donors↗
PubMed1994

[Metabolic and rheologic changes in long-term hypothermia of erythrocyte concentrates over 15 weeks].

With a multiple washing procedure in a chloride ion-free citrate-phosphate-glucose-adenine additive solution or with storage of red blood cells in a large volume of this solution, erythrocytes can be stored for 15 weeks at 4 degrees C. After 12 weeks' storage in this chloride-free solution the red blood cell parameters (2,3-DPG, glucose, lactose) measured are as good as stored erythrocytes resuspended in SAG-Mannitol after 21 days. Rheological parameters (morphology, filterability) show a maintenance of deformability of such preserved cells up to 84 days of storage. The preservation of erythrocytes by this method has the advantage that beside the hypothermic long-term storage (potential second aHIV screening of blood donors) the blood is of better quality in the first weeks of storage.

2,3-Diphosphoglycerate↗
PubMed1994

[Large volume lymphocytapheresis for the collection of peripheral stem cells].

We performed 29 large-volume leukaphereses of 20 patients for collection of peripheral blood stem cells. All patients have been pretreated with cytokines after chemotherapy. In 9 patients with precounts of > or = 3 x 10(9) mononuclear cells/l we achieved a sufficient transplantation doses with one LVL. If the MNC precount was < or = 3 x 10(9)/l we had to perform more than one LVL. On 16 patients we compared a standard apheresis procedure with the LVL procedure. It seems that especially patients with a lower MNC precount can profit from LVL. From patients with higher MNC precounts we harvested the double amount of MNCs, from patients with lower MNC precounts the triple amount.

Female↗
PubMed1994

[Improvement of storage capability of blood by the use of biocompatible absorbents].

A new filtration method for leucocyte and chloride ion depletion of erythrocyte concentrates in one step by DEAE cellulose was developed. After passage of the packed red cells through this filter material a chloride depletion of 70-80% and a leucocyte depletion of 90% could be reached. The 25 degrees C storage of this in-line-filtered red cells characterized by metabolic parameters (ATP, 2,3-DPG) suggests the possibility of a long-term red blood cell storage.

Absorption↗
PubMed1994

[Mechanical separation of erythrocyte concentrates and fresh plasma in autologous blood transfusion using Haemonetics MCS-3P].

The application of an autologous blood programme in hospitals is often limited by missing preconditions such as equipment, room, or staff. A component therapy in autologous blood donation is now easily possible by an automated whole blood donation with cell separator MCS-3P which allows in one step the collection of one unit red cell concentrate and one unit of plasma in 7 min. The quality of the collected blood preparations meets the requirements.

Blood Preservation↗
PubMed1994

[Rejuvenation of autologous blood preserved by washing in glucose- adenine- phosphate- and citrate-containing solution].

Outdated red cell concentrates (RCC-SAGM) were washed with a chloride-free, glucose-adenine-phosphate-citrate preservation solution. After resuspension of the red cells in this solution a hypothermic storage for additional 63 days was performed. Quality parameters (2,3-DPG, glucose, lactose, free hemoglobin, pH, chloride, pO50, shape quality index, filtration index) of the preserved red blood cells became normal within 7-11 days after the rejuvenation procedure. The data prove that a rejuvenation of outdated blood by a simple washing procedure allows a post-storage time of 21 days.

Adenine↗
PubMed1994

[Mechanical donation of whole blood simultaneous extraction of concentrated erythrocytes and fresh plasma using MCS-3P].

The new 'Multi-Component System-3 pump' (MCS-3P) is an apheresis system giving the flexibility to collect red blood cells, plasma, and platelets in one step. The objective was to perform an automated donation of red cells and plasma (erythroplasmapheresis), collecting in less than 20 min 350 ml red cells including 80 ml of SAG-M and 400 ml plasma. For this study we have evaluated 32 donations. The results obtained for red blood cells (42 days) and plasma (after freezing) are as good as with standard collection (parameter such as Hb, Hk, MCV, MCHC, 2,3-DPG, ATP, free Hb and potassium, glucose, lactose, protein).

Adult↗
PubMed1994

[Autologous fibrin glue from preoperative blood or plasma donors].

Cryoprecipitate was prepared from autologous plasma donation (fresh frozen plasma). The composition of this cryoprecipitate (fibrinogen, factor XIII, fibronectin) meets the requirements for the fibrinogen component of a fibrin glue. The prepared glue has tensile strength values in dura mater gluing as good as the commercial tissue glues.

Blood Donors↗
PubMed1994

[Stem cell pheresis and deep temperature preservation--a problem of transfusion medicine?].

In Germany, Transfusion Medicine belongs to various medical disciplines. We would like to demonstrate our model of interdisciplinary collaboration in stem cell transplantation. Since 1989 we performed 339 leukaphereses in 53 patients. On average we got 1.4 x 10(8) MNC/kg body weight from one single apheresis procedure. To observe graft quality we measured the content of CD34-positive cells and the amount of CFU-GM. Despite diagnosis and therapeutical regimen the content of CD34+ cells was found to be 3.3% (0-20). The proliferation was 21.7 GM-CFU per 1 x 10(5) MNC seeded (0-393). The results of the first 17 transplantations showed a fast haematological recovery (WBS 1.0 Gpt/l after 9 days Plt 20 Gpt/l after 11 days). Close collaboration of Transfusion Medicine and Haematology leads to optimization of stem cell transplantation.

Blood Transfusion↗
PubMed1993

Posttransfusional changes of 2,3-diphosphoglycerate and nucleotides in CPD-SAGM-preserved erythrocytes.

BACKGROUND: Posttransfusional changes of preserved red blood cells can influence the oxygen equilibrium curve which is mainly affected by the concentration of erythrocyte 2,3-diphosphoglycerate (DPG). MATERIAL AND METHODS: The regeneration kinetics of DPG and nucleotides (ATP, ADP, AMP, GTP, GDP) was determined over a period of 0-48 h in surgically treated patients following transfusion of DPG-depleted packed red cells stored for 14 days in CPD-SAGM. RESULTS: 3 h after transfusion the DPG levels raised up to 40% of the patients' prior DPG concentrations. Complete regeneration of the DPG concentrations occurred 36-48 h after transfusion. Changes in the nucleotide pattern indicate, after a temporary decrease of ATP and GTP levels (after 10-30 min) and an activation phase (after 3-12 h), the full regeneration of these parameters 24-48 h after transfusion. CONCLUSIONS: The regeneration kinetics of DPG should be taken into consideration for transfusions with blood units stored for more than 14 days, especially in patients with reduced compensatory mechanisms (coronary and cerebral scleroses, pacemaker, etc.) and large transfusion volumes.

2,3-Diphosphoglycerate↗