Volker Weisbach

• Universitätsklinikum Erlangen

In skeletal muscle tissue engineering, innervation and vascularization play an essential role in the establishment of functional skeletal muscle. For adequate three-dimensional assembly, biocompatible aligned nanofibers are beneficial as matrices for cell seeding. The aim of this study was to analyze the impact of Schwann cells (SC) on myoblast (Mb...

Background For the purpose of skeletal muscle engineering, primary myoblasts (Mb) and adipogenic mesenchymal stem cells (ADSC) can be co-cultured and myogenically differentiated. Electrospun composite nanofiber scaffolds represent suitable matrices for tissue engineering of skeletal muscle, combining both biocompatibility and stability Although gro...

Chronic wounds depict a silent epidemic challenging medical professionals worldwide. Regenerative medicine uses adipose-derived stem cells (ADSC) in promising new therapies. In this study, platelet lysate (PL) as a xenogen-free substitute for foetal bovine serum (FBS) in ADSC culture was used to create an ADSC secretome containing cytokines for opt...

Adipose‐derived stromal cells (ADSC) are increasingly used in clinical applications due to their regenerative capabilities. However, ADSC therapies show variable results. This study analysed the effects of specific factors of ex‐obese patients on ADSC functions. ADSC were harvested from abdominal tissues (N = 20) after massive weight loss. Patients...

For the purpose of skeletal muscle tissue engineering, different cell types have been investigated regarding their myogenic differentiation potential, including co-cultured myoblasts and adipogenic mesenchymal stromal cells (Mb/ADSC). As neural cells enhance synaptic junction formation, the aim of this study was to co-culture Schwann cells (SCs) wi...

Ionizing radiation has become an integral part of modern cancer therapy regimens. Various side effects, such as radiation dermatitis, affect patients in acute and chronic forms and decrease therapy compliance significantly. In this study, primary keratinocytes were irradiated in a 2-dimensional (2D) culture as well as on a 3-dimensional (3D) collag...

Primary myoblasts (Mb) and adipose derived mesenchymal stromal cells (ADSC) can be co-cultured and myogenically differentiated in the process of skeletal muscle tissue engineering. Electrospun composite nanofiber scaffolds represent suitable matrices for tissue engineering of skeletal muscle, combining biocompatibility and stability. Although growt...

The members of a Caucasian family were genetically analyzed on suspicion of hereditary protein S deficiency. A novel mutation, c.1904T>C, associated with severe quantitative protein S deficiency was found. The novel PROS1 mutation was identified by sequencing of the PROS1 gene coding sequence. The identified c.1904T>C point mutation results in p.Ph...

Introduction: For the regeneration of large volume tissue defects, the interaction between an-giogenesis and osteogenesis is a crucial prerequisite. The surgically-induced angiogenesis by means of an arteriovenous loop (AVL), is a powerful methodology in order to enhance vas-cularization of osteogenic matrices. Moreover, the AVL increases oxygen a...

The microvascular endothelial network is essential for bone formation and regeneration. In this context, endothelial cells not only support vascularization but also influence bone physiology via cell contact‐dependent mechanisms. In order to improve vascularization and osteogenesis in tissue engineering applications, several strategies have been de...

HLA-A*01:234 was identified by next generation sequencing and confirmed by Sanger sequencing.

HLA-C*01:136 identified by next generation sequencing and confirmed by Sanger sequencing

Rationale Oral anticoagulants and painkillers, some with an additional effect on the coagulation system, are widely used and are therefore prone to abuse and (intentional) overdose. We report the case of a patient with a massive mixed anticoagulant intoxication. Patient concerns The patient had ingested 1960 mg rivaroxaban, 31.5 mg phenprocoumon,...

Background: We present a multivariate test system using flow cytometry after in-vitro lymphocyte stimulation using 5 mitogens and 7 antigens to describe in-vitro immunofunction. Methods: The present work is a crucial step towards establishing a simple, CFSE-based, multivariate test system that can describe the dynamics of stimulus-induced lympho...

Background: Quantification of CD34+ cells in peripheral blood stem cell apheresis is normally performed by single platform flow cytometric measurements according to the ISHAGE protocol. Peripheral blood stem cell concentrates (PBSC) produced by apheresis normally contain many T cells. Those T cells can be used for production of donor lymphocyte inf...

Sensitive and accurate methods to detect hematopoietic chimerism after hematopoietic stem cell transplantation (HSCT) are essential to evaluate engraftment and to monitor response to therapeutic procedures such as donor lymphocyte infusion. Continuous long-term follow up, however, requires large amounts of pre-HSCT samples limiting the application...

Background: In Germany, cord blood needs to be transported to the processing facility to be processed and cryopreserved within 48 hours after collection according to national guidelines. During that time, a temperature of 22 ± 4 degrees C must be maintained. The purpose of this study was to analyse the influence of temperature during transport and...

In most cases, the amount of hematopoietic stem and progenitor cells (HSPCs) in a single cord blood (CB) unit is not sufficient for allogenic transplantation of adults. Therefore, two CB units are usually required. The ex vivo expansion of HSPCs from CB in coculture with mesenchymal stroma cells (MSCs) might be an alternative. It was investigated,...

Background: Quantification of CD34+ cells in peripheral blood stem cell apheresis is normally performed by single platform flow cytometric measurements according to the ISHAGE protocol. Peripheral blood stem cell concentrates (PBSC) produced by apheresis normally contain many T cells. Those T cells can be used for production of donor lymphocyte in...

Posttranslational modifications (PTMs) have been reported in hemoglobin (Hb) treated with ROS/RNS in cell-free experiments. However, little is known about oxidative PTMs of Hb occurring within the erythrocytes. The aim of this study is to characterize the patterns of Hb PTMs in erythrocytes under oxidative stress. Using mass spectrometry, we invest...

4352 Background and objectives We have recently shown that memory B-lymphocytes from murine CMV immune donor animals adoptively transferred into immunodeficient mice were highly effective in protecting from a viral infection indicating a therapeutic potential of virus specific memory B-cells. These preclinical data provided evidence that a cell-ba...

There is a lack of data on the usage of plasma derived/recombinant coagulation factor concentrates (PD/RCFC) regarding diagnostic categories. An audit of PD/RCFC and blood component usage at a tertiary care teaching hospital in northern Bavaria was conducted. All blood components and PD/RCFC transfused at a university hospital (Erlangen, Germany) d...

Disposable tube systems used in extracorporeal circulation and blood bags are manufactured from Polyvinylchloride (PVC). To make the PVC polymer flexible, the plasticizer DEHP is added. DEHP leaches out into the blood contacting the PVC surface. That way the patient is exposed to DEHP. DEHP is a known reproductive and developmental toxicant in anim...

For intrauterine transfusion and some other rare indications, irradiation and washing or adjustment to an elevated haematocrit is necessary. No data are currently available indicating whether irradiation of red blood cell concentrates (RBCs) might impair the mechanical stability of erythrocytes during centrifugation leading to elevated haemolysis....

In the member states of the European Union, the field of cell-based medicine and tissue preparations is determined by the law of the European Community (EC). The implementation of the EC directives is mandatory and makes Community law binding in the EU Member States. The Tissues and Cells Act of July 20, 2007 transposed the Directive 2004/23/EC, wh...

The objective of this study was to assess the impact of perioperative transfusion on the prognosis of patients who underwent complete (R0) resection of oral squamous cell carcinoma and reconstruction by microvascular flaps. By following an inclusion and exclusion protocol, 223 patients were included in the study who underwent R0 resection of oral s...

Background Autologous serum eye drops are an important therapy option in severe ocular surface disorders and the therapeutic effectiveness has been demonstrated in many clinical studies. The production and use of autologous serum eye drops is strictly controlled by legal regulations in Germany: Both the German Medicines Act (AMG) and the Blood Tran...

There exists only very few data on in vitro and in vivo effects of gamma irradiation of red blood cells (RBCs) that have been leukoreduced by filtration before a subsequent irradiation. Reported studies reflect neither the current Food and Drug Administration (FDA) nor the European recommendations on timing of irradiation and subsequent storage. We...

Autologous serum eye drops are an important therapy option in severe ocular surface disorders and the therapeutic effectiveness has been demonstrated in many clinical studies. The production and use of autologous serum eye drops is strictly controlled by legal regulations in Germany: Both the German Medicines Act (AMG) and the Blood Transfusion Act...

The standard mononuclear cell (MNC) program of the COM.TEC device (Fresenius HemoCare GmbH) showed excellent collection efficiency of CD14+ monocytes. A major disadvantage was high content of residual cells in MNC harvests, which could influence dendritic cell (DC) culture. The autoMNC program (COM.TEC) was compared with the standard MNC program (n...

The aim of this study was to investigate the effect of gamma irradiation with 30 Gy on the coagulation system in leukoreduced fresh-frozen plasma (FFP). In 74 FFP units that had been stored for 352 +/- 103 days below -30 degrees C, the following variables were determined in parallel in an irradiated and not irradiated half: prothrombin time (PT); a...

The Fresenius COM.TEC cell separator is a new device for producing white cell concentrates (WBCs) and leukoreduced single-donor platelet concentrates (SDPs) and performing therapeutic cytapheresis and plasmapheresis that might replace the Fresenius systems AS104 and AS.TEC 204. This novel system's performance was evaluated for producing leukoreduce...

Semaphorin 7A (Sema7A), the protein that carries the JMH blood group antigen, is involved in immune responses and plays an important role in axon growth and guidance. Because previous serologic studies on red blood cells (RBCs) suggested a considerable diversity of Sema7A, the present study was designed to elucidate the complex picture of the molec...

The hepatitis B vaccination policy in Germany was intensified by the implementation of hepatitis B vaccination for adolescents in the vaccination calendar in 1995. To investigate the effect of this measure on the hepatitis B vaccination coverage of healthy adults, we analysed the hepatitis B vaccination status of blood donors. Furthermore, the reas...

The common adverse effects of traditional nonsteroidal antiinflammatory drugs on renal function include reductions in renal blood flow, glomerular filtration rate, and sodium and potassium excretion, mainly via inhibition of renal cyclooxygenase. We designed the present study to determine the effects of IV paracetamol or parecoxib on renal function...

To compare the performance of seven currently available test systems in the detection of erythrocyte alloantibodies (ab), we tested in parallel 446 sera samples containing red cell ab [368 sera samples with ab that are assumed to be clinically significant (cs-ab) and 78 sera samples with ab that are assumed to be of minor clinical significance (ms-...

The aim of this study was to investigate the occurrence of hypotension in the 24-hour period after preoperative autologous blood donation (PABD) in patients with and without hypertension. In 20 patients, 24-hour ambulatory blood pressure monitoring (ABPM) was performed before PABD was started and on every donation day in two repeated phlebotomies....

Only a few systematic studies have examined the effect of variable produced small platelet (PLT) aliquots on PLT function before transfusion to neonates. Although neonatal transfusion could be critical, no standardization of production or systematic quality controls have been introduced so far. PLT split products were prepared in three different wa...

Rare clinical conditions cause the need for washed platelet (PLT) concentrates (PCs). Saline-washed PCs can only be stored shortly, however, owing to lack of substrates for PLT metabolism. New PLT additive solutions (PASs) contain such substrates and might be used alternatively. The in vitro quality of apheresis PCs washed with Composol-PS or modif...

The COM.TEC cell separator (Fresenius Hemocare), equipped with the MNC program (single-stage chamber) and the PBSC-LYM program (dual-stage chamber), was evaluated for CD 14+ cell collection regarding cell yields, collection efficiencies (CEs), and the content of residual cells in harvests. Twenty-four non-cytokine-stimulated donors underwent 5-L mo...

Platelets (PLTs) contain an assortment of growth factors (GFs), in particular PLT-derived GFs (PDGFs), transforming GFs (TGFs), and vascular endothelial GF (VEGF) (1). By topical release and action of these GFs simultaneously with thrombus formation and bleeding cessation, PLTs initiate the processes of wound repair, angiogenesis, and defense again...

In this study we investigated human metabolism and excretion of DEHP after intravenous exposure. For this purpose we determined the five major DEHP metabolites in urine samples of a volunteer before and after a platelet donation (dual-needle technique). Plateletpheresis procedures are known to cause a significant DEHP exposure. We observed a sharp...

Each year thousands of healthy volunteers undergo apheresis procedures to donate blood components and safe lives. However, many disposables used in apheresis contain di(2-ethylhexyl)phthalate (DEHP). This way, donors are exposed to DEHP, which is a reproductive and developmental toxicant in animals and a suspected endocrine modulator in humans. We...

New platelet (PLT) additive solutions (PASs) allow a plasma carryover of < 30% in PLT concentrates. This implicates the need to collect apheresis PLT concentrates at very high PLT concentrations: so-called dry PLTs (DPs). We used the TRIMA, with software version 4 (TRIMA V4), to collect such DPs and investigated the in vitro quality of these PLTs w...

It has been the aim of the present clinical study to assess the reduction of the hemoglobin value and the frequency of blood transfusions during bimaxillary orthognathic surgery and to discuss the clinical consequences. Fifty-six patients (31 female, 25 male; mean age, 28.6 +/- 13.0 years; range, 14 to 66 years) were operated on. Twenty-nine patien...

Standard plateletpheresis techniques and effects on platelet (PLT) donors were investigated to provide an informative basis for advancement of apheresis software. Three paired groups with 33 male and 22 female blood donors were prospectively investigated by analyzing blood counts of donors and products. Four apheresis platforms, the COBE Spectra LR...

Although the risk of transfusion-transmitted hepatitis B virus (TT-HBV) infection is very low, it still exists. Therefore, introduction of further precautions to reduce this risk is discussed at present. However, so far no data are available about the HBV vaccination status among blood donors (BDs). We compared HBV vaccination status of apheresis d...

Recently, long-standing elevations of soluble growth factors released from platelets (PLTs) after contact with artificial surfaces during dialysis were described. They could be jointly responsible for the high frequency of death from cardiovascular diseases in dialysis patients. There are no comparable data on the extent and the duration of a growt...

We introduced monitoring of mononuclear cell (MNC) counts to obtain enhanced donor control and a stable quality of MNC products, because there are limited data available about blood donors after serial leukapheresis (LP) procedures. In a prospective paired study, 13 male healthy blood donors underwent 10-L LP procedures performed on two apheresis d...

At present, it is uncertain whether intraoperative autotransfusion of irradiated shed blood in cancer surgery is advantageous for the patient compared to homologous blood transfusion. The answer to this question fundamentally depends on the respective figures for the risks of homologous blood. The remaining importance of transfusion-associated immu...

The implementation of alternative blood conservation strategies to their full extent before preoperative autologous blood donation (PABD) is applied might reduce costs and blood donation risks for patients undergoing elective surgery. If PABD has to be performed, it has to be arranged as effective as possible. This includes an optimal time schedule...

The implementation of alternative blood conservation strategies to their full extent before preoperative autologous blood donation (PABD) is applied might reduce costs and blood donation risks for patients undergoing elective surgery. If PABD has to be performed, it has to be arranged as effective as possible. This includes an optimal time schedule...

No data are currently available on the quality of washed prestorage leucocyte-depleted red blood cell concentrates (RCCs). Five groups of RCCs stored in additive solution (SAG-M) were washed. The groups differed in the age of RCCs (2-5 days or 11-15 days), the temperature during the washing procedure and a 6-h storage period (4 degrees C or room te...

In cancer and transplantation therapy apheresis devices and software of optimum standards are required for the collection of high cell yields with high purity of the desired cell fraction. In a paired study, 15 healthy blood donors underwent four 10-L leukapheresis procedures (197 +/- 33 min) with an inlet blood flow rate of 60 mL per minute by use...

It has been the aim of the present prospective clinical study to assess the morbidity following the harvest of bone from the anterior and posterior ilium in elective preprosthetic augmentations. Fifty consecutive healthy patients (30 female, 20 male, mean age 52.5+/-9.3 years, range 31 years to 65 years) underwent augmentations of implant sites by...

The properties of red blood cell (RBC) concentrates stored in different additive solutions have been previously examined under laboratory conditions at the end of shelf-life. However, whether these data are representative for RBC units used in clinical practice has not been shown. Therefore, we examined 164 RBC units from six manufacturers outdated...

Monocytes collected by leukapheresis are increasingly used for dendritic cell (DC) culture in cell factories suitable for DC vaccination in cancer. Using modified MNC programs on two apheresis systems (Cobe Spectra and Fresenius AS.TEC204), leukapheresis components collected from 84 patients with metastatic malignant melanoma and from 31 healthy ma...

Umbilical cord blood processing with standard centrifugation techniques is performed in open systems and results in varying cell and volume recoveries. Forty umbilical cord blood donations were randomly assigned to processing either with a microprocessor-controlled cell separator equipped with closed disposables or with a manual separation procedur...

Life-threatening gastrointestinal hemorrhage in Crohn’s disease is rare but well recognized and represents about 1% of the cases for hospital admissions in Crohn’s disease. Patients with ileocolic location of disease are More likely to have severe hemorrhage and May require resection of the small bowel, which is the Most frequently performed intest...

BACKGROUND: Quality assurance of blood transfusion covers institutions, personnel, and procedures involved in preparing, issuing, and using blood components. The accuracy of data related to blood component transfusions is a tool for quality control in the transfusion service. STUDY DESIGN AND METHODS: A study of the accuracy of data records of the...

BACKGROUND: A cell separator (Spectra, Gambro BCT) with an integrated leukoreduction system (LRS) for producing WBC-reduced single-donor platelet concentrates has been shown to result in a slightly reduced collection efficiency as compared to the former Spectra system without LRS. A novel modified system for improved collection efficiencies (LRS Tu...

To reduce the production costs of single-donor platelets (SDPs), a study was conducted to investigate whether plasma collected as a by-product of plateletpheresis satisfies the quality requirements for FFP without impairing the quality of the SDP component. Ninety-two donors with platelet (PLT) counts <270 x 10(9) per L underwent plateletpheresis u...

Factor VIII inhibitors can trigger bleeding complications especially if they remain unrecognized (1). In the following case a prolongation of the activated partial thromboplastin time (aPTT) was found using a global coagulation test that was carried out routinely before an enoral biopsy of a mucous membrane. Further analysis of the coagulation fact...

Factor XIII inhibitor, a rare cause of coagulopathy, is usually not detected by screening tests, e.g. activated partial thromboplastin time (aPTT) and thromboplastin time (PT) (1). The following report describes the case of a patient with known Coombs-reactive red cell autoantibodies. Factor XIII inhibitor was detected with delay because severe hem...

The effect of gamma radiation on single-donor apheresis platelet concentrates (SDPs) has been elucidated only incompletely. The only existing report on the function of SDPs stored in the irradiated state found a deterioration in the in vitro aggregability at the end of shelf life in SDPs divided before irradiation with 1500 cGy. The in vitro proper...

Modern cell separators allow the collection of two plateletpheresis concentrates (PCs) at one session. This study evaluates the quality of PCs stored as double concentrates in standard storage containers of two manufacturers. We collected 20 PCs that contained 4.5 x 10(11) platelets in 375 ml plasma (10 using the COBE Spectra and 10 using the Frese...

Platelet quality after storage strongly depends on the pre-storage quality as well as on the storage conditions determined by the storage container. In this paired study, we evaluated two different containers (MedSep CLX and Delmed DPL-110). The Fresenius AS104 cell separator was used to prepare 17 platelet concentrates that were split and distribu...

BACKGROUND: Compensatory RBC production during repeated preoperative autologous blood donation (PABD) shows marked interindividual variability. This study was performed to reveal variables that might be useful to predict the amount of the erythropoietic response to PABD in an individual patient who was not iron deficient. STUDY DESIGN AND METHODS:...

MNCs for adoptive immunotherapy may be collected by leukocytapheresis with a cell separator. Six healthy cytapheresis donors donated two MNC concentrates on a cell separator (AS.TEC 204, Fresenius): one on the standard MNC program and one on a modified MNC program with reduced centrifuge velocity that leads to a lower platelet contamination. Sevent...