Function, expression and localization of annexin A7 in platelets and red blood cells: Insights derived from an annexin A7 mutant mouse

BACKGROUND: Annexin A7 is a Ca(2+)- and phospholipid-binding protein expressed as a 47 and 51 kDa isoform, which is thought to be involved in membrane fusion processes. Recently the 47 kDa isoform has been identified in erythrocytes where it was proposed to be a key component in the process of the Ca(2+)-dependent vesicle release, a process with which red blood cells might protect themselves against an attack by for example complement components. RESULTS: The role of annexin A7 in red blood cells was addressed in erythrocytes from anxA7(-/-) mice. Interestingly, the Ca(2+)-mediated vesiculation process was not impaired. Also, the membrane organization appeared not to be disturbed as assessed using gradient fractionation studies. Instead, lack of annexin A7 led to an altered cell shape and increased osmotic resistance of red blood cells. Annexin A7 was also identified in platelets. In these cells its loss led to a slightly slower aggregation velocity which seems to be compensated by an increased number of platelets. The results appear to rule out an important role of annexin A7 in membrane fusion processes occurring in red blood cells. Instead the protein might be involved in the organization of the membrane cytoskeleton. Red blood cells may represent an appropriate model to study the role of annexin A7 in cellular processes. CONCLUSION: We have demonstrated the presence of both annexin A7 isoforms in red blood cells and the presence of the small isoform in platelets. In both cell types the loss of annexin A7 impairs cellular functions. The defects observed are however not compatible with a crucial role for annexin A7 in membrane fusion processes in these cell types

Probability of success in the search for a related bone marrow donor in Cologne, Germany using HLA-A, -B and-DRB1 haplotype frequencies

Between 2004 and 2013, 603 patients and their relatives (n=1297) were typed as part of the search for a suitable HLA-matched donor in their nuclear and extended families at the central service provider for transfusion medicine at the University Hospital of Cologne. The high success rate in finding donors over the years at our center (38.1%) led us to examine our database retrospectively in order to evaluate the donor search and haplotype frequencies (HFs) in the sample. Our goal was to identify the factors contributing to this high success rate and also to compare the HFs we observed with other reported haplotype frequency estimations (HFE) for the Cologne area. Probability estimations for a successful donor search were constructed based on the HFEs for the sample

Familial acquired thrombotic thrombocytopenic purpura in siblings - no immunogenetic link with associated human leucocyte antigens

Acquired immunoglobulin G (IgG)-mediated thrombotic thrombocytopenic purpura (TTP) has not yet been described in non-twin siblings. We report two cases of acquired TTP in Caucasian sisters with inactive ADAMTS13 metalloprotease due to ADAMTS13 autoantibodies suggesting a role of genetic determinants in this life-threatening disease. However, human leucocyte antigen (HLA) class II types presumably associated with acquired TTP were not identified in the patients, indicating that HLA class II typing may not be useful in acquired TTP risk assessment of family members

Comparison of three noninvasive methods for hemoglobin screening of blood donors

BackgroundTo prevent phlebotomy of anemic individuals and to ensure hemoglobin (Hb) content of the blood units, Hb screening of blood donors before donation is essential. Hb values are mostly evaluated by measurement of capillary blood obtained from fingerstick. Rapid noninvasive methods have recently become available and may be preferred by donors and staff. The aim of this study was to evaluate for the first time all different noninvasive methods for Hb screening. Study Design and MethodsBlood donors were screened for Hb levels in three different trials using three different noninvasive methods (Haemospect [MBR Optical Systems GmbH & Co. KG], NBM 200 [LMB Technology GmbH], Pronto-7 [Masimo Europe Ltd]) in comparison to the established fingerstick method (CompoLab Hb [Fresenius Kabi GmbH]) and to levels obtained from venous samples on a cell counter (Sysmex [Sysmex Europe GmbH]) as reference. The usability of the noninvasive methods was assessed with an especially developed survey. ResultsTechnical failures occurred by using the Pronto-7 due to nail polish, skin color, or ambient light. The NBM 200 also showed a high sensitivity to ambient light and noticeably lower Hb levels for women than obtained from the Sysmex. The statistical analysis showed the following bias and standard deviation of differences of all methods in comparison to the venous results: Haemospect, -0.221.24; NBM, 200 -0.12 +/- 1.14; Pronto-7, -0.50 +/- 0.99; and CompoLab Hb, -0.53 +/- 0.81. ConclusionNoninvasive Hb tests represent an attractive alternative by eliminating pain and reducing risks of blood contamination. The main problem for generating reliable results seems to be preanalytical variability in sampling. Despite the sensitivity to environmental stress, all methods are suitable for Hb measurement

Emergency Medical Equipment On Board German Airliners

Background. Medical emergencies often occur on commercial airline flights, but valid data on their causes and consequences are rare. Therefore, it is unclear what emergency medical equipment is necessary. Although a minimum standard for medical equipment is defined in regulations, additional material is not standardized and may vary significantly between different airlines. Methods. German airlines operating aircrafts with more than 30 seats were selected and interviewed with a 5-page written questionnaire between August 2011 and January 2012. Besides pre-packed and required emergency medical material, drugs, medical devices, and equipment lists were queried. If no reply was received, airlines were contacted another three times by e-mail and/or phone. Descriptive analysis was used for data presentation and interpretation. Result. From a total of 73 German airlines, 58 were excluded from analysis (eg, those not providing passenger transport). Fifteen airlines were contacted and data of 13 airlines were available for analysis (two airlines did not participate). A first aid kit was available on all airlines. Seven airlines reported having a doctor's kit, and another four provided an emergency medical kit. Four airlines provided an automated external defibrillator (AED)/electrocardiogram (ECG). While six airlines reported providing anesthesia drugs, a laryngoscope, and endotracheal tubes, another four airlines did not provide even a resuscitator bag. One airline did not provide any material for cardiopulmonary resuscitation (CPR). Conclusions. Although the minimal material required according to European aviation regulations is provided by all airlines for medical emergencies, there are significant differences in the provision of additional material. The equipment on most airlines is not sufficient for the treatment of specific emergencies according to published medical guidelines (eg, for CPR or acute myocardial infarction)