Quantitation of circulating short-chain fatty acids in small volume blood samples from animals and humans

BACKGROUND

The role of gut microbiota in human health has been intensively studied and more recently shifted from emphasis on composition towards function. Function is partly mediated through formed metabolites. Short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate as well as their branched analogues represent major products from gut fermentation of dietary fibre and proteins, respectively. Robust and high-throughput analysis of SCFAs in small volume blood samples have proven difficult. Major obstacles come from the ubiquitous presence of SCFAs that leads to contaminations and unstable analytical results because of the high volatility of these small molecules. Comprehensive and comparable data on the variation of SCFAs in blood samples from different blood matrices and mammal species including humans is lacking. Therefore, our aim was to develop and evaluate a stable and robust method for quantitation of 8 SCFAs and related fermentation products in small volume blood plasma samples and to investigate their variation in humans and different animal species.

RESULTS

Derivatization was a successful approach for measurement of SCFAs in biological samples but quenching of the derivatization reaction was crucial to obtain long-term stability of the derivatized analytes. In total 9 compounds (including succinic acid) were separated in 5 min. The method was linear over the range 0.6-3200 nM formic (FA), acetic (AA), 0.3-1600 nM propionic (PA), and 0.16-800 nM for butyric (BA)-, isobutyric (IBA)-, valeric (VA)-, isovaleric (IVA)-, succinic (SA) and caproic acid (CA). The precision ranged ≤12 % within days and ≤28 % between days (except for CA and VA) in three different plasma quality control (QC) samples (29 batches analyzed over 3 months). The extraction recovery was on average 94 % for the different SCFAs. Typical interquartile range (IQR) concentrations (μM) of SCFAs in human plasma samples were 168 μM (FA), 64 μM (AA), 2.2 μM (PA), 0.54 μM (BA), 0.66 μM (IBA), 0.18 μM (VA), 0.40 μM (IVA), and 0.34 μM (CA). In total, 55 samples per batch/day were successfully analyzed and in total 5380 human plasma samples measured over a 3-year timespan.

SIGNIFICANCE

The developed UHPLC-MS based method was suitable for measuring SCFAs in small blood volume samples and enabled robust quantitative data.

[The heart in cases of viral, bacterial and parasitic infections]

The heart can be the primary target for a viral, bacterial or parasitic infection (primary myocarditis/inflammatory cardiomyopathy). It can also participate in the "collateral damage" due to toxins, chemo- and cytokines, autoreactive antibodies or the native and acquired immune response through T- and B-cells, monocytes and macrophages (secondary myocarditis/inflammatory cardiomyopathy), when it is not the dominant organ of the disease. Infective agents show remarkable organ specificity: viral infections, toxic and autoreactive processes affect primarily the myocardium and the pericardium, whereas bacterial infections prefer endothelial surfaces and cause endocarditis and, less frequently, pericarditis. They are even discussed as part of the inflammatory process involved in coronary artery disease. Infective agents and their adequate diagnosis and treatment are discussed for these clinical entities according to current guidelines and clinical pathways.

[Chronic critical ischemia of the lower leg: pretherapeutic imaging and methods for revascularization]

Each year 1-2% of patients with peripheral arterial occlusive disease (pAOD) develop critical limb ischemia (CLI), characterized by rest pain and peripheral ulcer or gangrene. This aggravation of the disease is accompanied by an increase of the 1-year mortality rate up to 25% and a similarly increased frequency of major amputation. We can choose between conservative, endovascular, and surgical procedures for an adequate therapy of the underlying vascular stenoses or occlusions. Yet, clear therapeutic recommendations only exist for suprapopliteal lesions. However, in a number of cases, especially in diabetics, target lesions have an infrapopliteal location. Since endovascular procedures have undergone significant improvement in the last few years, the following review discusses methods for infrapopliteal revascularization taking into consideration the newest publications on this topic.

[Stenting of the SFA--indications, techniques, results]

Aggressive risk factor modification, change of eating habits, exercise programs, and forceful antiplatelet therapy are the most important tools for the treatment of PAOD in symptomatic patients suffering from intermittent claudication. There are however no guidelines for revascularization at this stage. Endovascular treatment has been increasingly utilized over the last decade and increasingly displaced vascular surgery. Amongst numerous endovascular techniques beside PTA, stents meanwhile play the most important role due to constant technical progress. Results regarding the rate of restenosis or patency rates still remain worse compared to other vascular beds. This paper gives a review over recent results, currently available stent techniques, and possible indications for the endovascular therapy of an artery, which has turned out to be the biggest ordeal for material and construction of stents.

Investigation on Radiofrequency and Laser (980nm) Effects after Endoluminal Treatment of Saphenous Vein Insufficiency in an Ex-vivo Model

OBJECTIVES

An ex-vivo model for the experimental evaluation of endoluminal thermal procedures for occlusion of saphenous veins was developed. Radiofrequency obliteration (RFO) and endovenous laser therapy (ELT) were compared using this model.

DESIGN

Experimental ex-vivo treatment study.

MATERIALS AND METHODS

The model consists of the subcutaneous foot veins from freshly slaughtered cows which were reperfused in situ with heparinised bovine blood. The veins were treated with either radiofrequency (RFO n=5) or with endoluminal 980 nm laser light (ELT n=5) using a continuous pull-back for RFO and a stepwise illumination and pull-back protocol for ELT. Immediately after treatment perivenous tissue and veins were examined macroscopically. In a second study the same treatment parameters were used in four further vein segments with RFO (n=2) and ELT (n=2). These vein segments were examined microscopically in HE-stained histological sections.

RESULTS

Induration of the vessel wall and contraction of the vessel lumen were observed after RFO. Laser treatment produced carbonised lesions of the vein wall. After 12-24 laser exposures these lesions often became transmural, causing complete perforation of the vessel wall. Histological evaluation after radiofrequency treatment demonstrated homogenous circular thermal tissue alteration with disintegration of intima and media structures. Histological evaluation after endovenous laser treatment showed large variations of thermal tissue effects. Tissue effects ranged from major tissue ablation and vessel wall disruption to minor effects located between laser exposures and on the opposite vessel wall.

CONCLUSIONS

Our model is suitable for systematic scientific evaluation of endovenous thermal occlusion procedures. Our first results and theoretical considerations indicate that endovenous laser treatment should be modified in order to ensure controlled homogenous circular thermal damage, avoiding vessel wall perforation and damage to perivascular structures.

Pathophysiology and Aetiological Diagnosis of Inflammatory Myocardial Diseases with a Special Focus on Parvovirus B19

Inflammatory processes induced by viral or bacterial infections are believed to be one of the major pathogenetic mechanisms in myocardial diseases. Although the reason for progression to myocardial failure is not fully understood, postulated mechanisms include persistent viral infection alone or in combination with autoimmune processes. A variety of cardiotropic viruses have been identified to elicit myocarditis, with enteroviruses and adenoviruses as the most frequent causative agents in children and adolescents. However, parvovirus B19 (PVB19) has recently emerged as another potential pathogen in adult patients associated with inflammatory heart disease. Many dimensions of inflammatory heart disease coexist while different phases of the disease progress simultaneously: phase 1 is dominated by viral infection, phase 2 by the onset of (probably) multiple autoimmune reactions, and phase 3 by the progression to cardiac dilatation without the role of an infectious agent and cardiac inflammation. Taking these mechanisms into account, screening for viral and bacterial genome by polymerase chain reaction (PCR) and detection of inflammatory infiltrates by immunohistochemistry are considered crucial for establishing an aetiological diagnosis, thereby allowing initiation of specific therapeutic strategies. In a large cohort of 3345 consecutive patients with left ventricular dysfunction evaluated over a period of 10 years, prevalence of PVB19, coxsackievirus (CVB), human cytomegalovirus (HCMV), influenza A virus and adenovirus (ADV) genome was assessed by PCR. Inflammatory infiltrates within the myocardium were detected by immunohistochemistry according to the WHF criteria and by histopathology according to the Dallas criteria of myocarditis. For control, endomyocardial samples of patients with arterial hypertension were studied. Parvovirus B19 was the most often detected virus in all patient subgroups, with positivity ranging from 17% to 33%. Except for PVB19, CVB RNA (3%), ADV (2%) and CMV (3.9%) were the most frequently detected viral genomes. Interestingly, detection of PVB19 genome was significantly correlated with inflammatory heart disease and reduced ejection fraction. Importantly, an aetiological diagnosis requires the immunohistochemical and molecular biological investigation of endomyocardial biopsies. Such an approach may change the management of these diseases in the future. One of the aims of the study was to reveal the underlying dominant pathophysiological mechanisms in a for deciding on the most approriate therapy.

Elektive Therapie des asymptomatischen infrarenalen Aortenaneurysmas

Summary. In recent years, endovascular operations on infrarenal aortic aneurysm (EVAR) have not only been acknowledged as an alternative, but have become an indispensable "tool of the trade" for the vascular surgeon. As documented in many studies, perioperative morbidity is definitely much lower than in open surgery. In the long term, open surgery is also subject to complications such as rupture or aorto-enteral fistulae which necessitate secondary operations with their associated risks. There are some valid studies documenting a significantly lower mortality for EVAR than for open surgery. These datas were recently confirmed with high evidence level by the published results of UK-EVAR trial 1. The other randomized trials are currently ongoing. If the lower morbidity and lethality rate for EVAR is confirmed in these studies, the establishment of the indication for aortic aneurysm must be reconsidered with regard to the risk profile and the maximum diameter. The fact that long-term results are not yet available for the endovascular operation introduces a factor of uncertainty. Intensive follow-up observation is therefore an absolute prerequisite in patients who have undergone endovascular treatment. If the establishment of the indication is appropriate, with the new vascular prosthesis endoleaks are no longer an insoluble problem. The two methods should not be regarded as mutually competitive, but as complementary components of the treatment spectrum at every vascular center.

[Vascular injuries in extremities]

Vascular injuries of the extremities account for most instances of vascular trauma (ca. 70%), and they entail a risk of amputation about 10-20%. According to the kind of force that has acted, arterial trauma is classified as direct or indirect. The scale of hemorrhage and peripheral ischemia depend on the nature and severity of the arterial lesion. In patients with multiple injuries, routine use of Doppler sonography and duplex sonography can facilitate early diagnosis and treatment of vascular injuries. With great certainty, clinical examination and an AB or WB index of >1.0 can rule out the presence of vascular injury that requires treatment. After excluding further life-threatening injuries, surgery should be performed immediately when there is critical ischemia, squirting hemorrhage, or a rapidly expanding hematoma. Angiography or duplex sonography findings determine the further procedure in vascular injuries that do not require immediate treatment. Occlusion of a reconstructed artery, manifestation of a compartment syndrome, and insufficient anticoagulation are the main factors affecting the risk of amputation.

[Value of MR angiography in follow-up after cruro-pedal bypass surgery]

Patients after crural or pedal revascularization need a consequent surveillance to prevent graft failure. We compared the results of the clinical examination including duplexscanning with contrast-enhanced magnetic resonance angiography (MRA). 26 bypass grafts were evaluated for potential stenosis in five locations. Using both techniques, 93 of 109 locations were classified identically. 10 of 16 locations which were categorized differently were reviewed angiographically (DSA). In contrast to duplexscanning, MRA detected 3 high grade stenosis, which had to be dilatated percutaneously. MRA should be used regularly in surveillance programs of distal bypass grafting.

Coexpression of p21(WAF1/CIP1) in adenovirus vector transfected human primary hepatocytes prevents apoptosis resulting in improved transgene expression

Replication-deficient adenovirus (Ad vector) is one of the most effective gene transfer systems. However, its employment in human gene therapy trials is hampered by Ad vector associated cytotoxicity and induction of apoptosis of the infected cells. Here, we identify one underlying mechanism as uncoupling of S phase and mitosis of the cell cycle leading to apoptosis and decline of transgene expression. Moreover, we demonstrate a strategy to avoid Ad vector associated cytotoxicity and induction of apoptosis in human primary hepatocytes by coinfection of Ad vector carrying the cDNA of choice and the cell cycle regulator p21(WAF1/CIP1) (p21). In addition, animal experiments were performed using Ad vector directed coexpression of p21 and human alpha 1-antitrypsin. As serum analysis of alpha 1-antitrypsin after Ad vector mediated gene transfer to the liver of mice revealed, this strategy resulted also in the improvement of transgene expression by two orders of magnitude. These data suggest that coexpression of p21 and Ad vector carrying a therapeutic gene may be a promising strategy to avoid cytotoxicity and induction of apoptosis leading to improved safety in human gene therapy.

[Stage-adapted therapy concept in ascending thrombophlebitis]

Varicophlebitis is the most frequent and important acute complication of a varicosed long and/or short saphenous vein. In view of the controversial discussion about the either conservative or surgical treatment, a clinically relevant classification of this syndrome appears useful: Stage I includes varicophlebitis without involvement of the respective junctional valve--in the groin or at the knee--and deep veins. While in Stage II the proximal part of the thrombus has reached the respective junctional valves of the long or short sapheneous vein, in Stage III it has entered the deep veins by means of these valves. In Stage IV the thrombus migrates via insufficient perforating veins into the deep system. Stages I and IV should be treated conservatively first, removal of the varicous veins should be performed after regression of the acute symptoms. Stages II and III should be considered an indication for urgent surgery. The surgical strategy consists of crossectomy, resection of the saphenous vein without stripping, radical excision of all varicous veins and ligature of insufficient perforating veins. In stage III the thrombectomy of the deep veins using the Fogarty-procedure must be carried out before any other measures are taken. In 1996 a total number of 40 limbs with ascending varicophlebitis (stage I = 16, stage II = 19, stage III = 5) was observed. 10 extremities (stage I = 2, stage II = 5, stage III = 3) underwent surgical treatment. 1 patient developed a deep infection of the groin, the average stay in hospital was 9 days.

In vitro susceptibility to TRAIL-induced apoptosis of acute leukemia cells in the context of TRAIL receptor gene expression and constitutive NF-kappa B activity

The TNF-related apoptosis-inducing ligand (TRAIL) is currently under evaluation as a possible (co-)therapeutic in cancer treatment. We therefore examined 129 cell samples from patients with de novo acute leukemia as to their constitutive susceptibility to TRAIL-induced apoptosis In vitro. Only 21 (16%) cell samples revealed at least 10% TRAIL-susceptible cells/sample as detected by flow cytometric annexinV staining after 24 h culture compared with medium control. Precursor B cell ALL samples (11 (27%) of 41) were more TRAIL-susceptible compared with AML (5 (9%) of 54; P < 0.05) but not compared with precursor T cell ALL (5 (15%) of 34; P = 0.20). Furthermore, we examined constitutive mRNA expression levels of TRAIL receptors R1-R4 by semi-quantitative RT-PCR (n = 58). Expression levels were heterogeneous, however, there was no significant correlation between the expression of the signal-transducing receptors (R1, R2) as well as of the decoy receptors (R3, R4) and TRAIL sensitivity in this series. Constitutive NF-kappa B activity has been shown to influence TRAIL susceptibility of leukemic cells. In 39 leukemic cell samples examined, we found a generally high NF-kappa B activity as detected by electrophoretic mobility shift assay which did not differ between TRAIL-susceptible and TRAIL-resistant cases. Finally, 49 acute leukemic cell samples were coincubated with doxorubicin in vitro. Doxorubicin sensitized four of 35 initially TRAIL-resistant samples and augmented TRAIL-induced apoptosis in two of 14 TRAIL-susceptible samples. In summary, constitutive TRAIL susceptibility differs between leukemia subtypes and does not correlate with mRNA expression levels of the TRAIL receptors R1-R4 as well as constitutive NF-kappa B activation status. The observed sensitization of leukemic cells to TRAIL by doxorubicin in vitro indicates that TRAIL should be further evaluated as to its possible role as an in vivo cotherapeutic in acute leukemia.

Apoptotic response to homoharringtonine in human wt p53 leukemic cells is independent of reactive oxygen species generation and implicates Bax translocation, mitochondrial cytochrome c release and caspase activation

In the present study, we investigated the in vitro apoptotic response of leukemic cells to the cellular stress induced by homoharringtonine (HHT), a plant alkaloid with antileukemic activity which is currently being tested for treatment of acute and chronic leukemias. A comparison of leukemic cell lines with different p53 gene status revealed a considerably higher sensitivity to HHT-induced apoptosis in the cells with a wt p53, and apoptotic events in wt p53 leukemia cells (MOLT-3 cell line) were studied in more detail. To this end, we examined components of apoptotic cascades including Bax expression and its intracellular localization, changes of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, cytochrome c release from mitochondria and activation of caspases. Bax protein levels did not increase despite an up-regulation of bax at mRNA level. However, Bax translocation from cytosol towards mitochondria was observed. In addition, we observed a release of cytochrome c from the mitochondria, and the localization changes of both Bax and cytochrome c were found already at the early, annexin V-negative stage of HHT-induced apoptosis. HHT-treated MOLT-3 cells revealed loss of MMP as well as activation of caspases demonstrated by DEVD-, IETD- and LEHD-tetrapeptide cleavage activity in the cell lysates. ROS levels only slightly increased in HHT-treated cells and antioxidants did not prevent apoptosis and MMP changes. Therefore, wt p53 leukemic cells respond to HHT-specific cellular stress by induction of ROS-independent apoptotic pathway characterized by translocation of Bax, mitochondrial cytochrome c release and activation of caspases.

Inhibition of in vitro spontaneous apoptosis by IL-7 correlates with bcl-2 up-regulation, cortical/mature immunophenotype, and better early cytoreduction of childhood T-cell acute lymphoblastic leukemia

In normal T-cell development, IL-7 plays a nonredundant role as an antiapoptic factor by regulating Bcl-2 expression in pro-T cells. In the current study, we addressed the roles of IL-7 and related cytokines as apoptosis-modulating factors in precursor T-cell acute lymphoblastic leukemia (T-ALL). To this end, leukemic blasts from pediatric patients with T-ALL were prospectively investigated as to their responsiveness to IL-7, IL-4, and IL-2 (in terms of modulation of spontaneous apoptosis, assessed by flow cytometry), cytokine receptor expression profiles, and expression levels of Bcl-2 and Bax proteins. IL-7, in contrast to IL-4 and IL-2, was highly efficient in apoptosis inhibition, and this effect correlated with the expression levels of IL-7Ralpha chain and with the up-regulation of Bcl-2 protein expression (P <.0001). Subclassification of T-ALL samples (n = 130) according to their in vitro IL-7 responses revealed that IL-7 refractory samples were more frequently positive for CD34 (P <.0001) and the myeloid-associated antigen CD33 (P =.01), whereas IL-7 responsiveness was associated with an expression of more mature differentiation-associated T-cell antigens (CD1a, surface CD3, CD4/8; P <.05). Furthermore, the extent of apoptosis inhibition by IL-7 in vitro quantitatively correlated with early cytoreduction as determined by the prednisone peripheral blood response on day 8 and cytoreduction in the marrow on day 15 (n = 87; P <.05). Multivariate analysis of the apoptosis-related parameters investigated, including spontaneous apoptosis, its inhibition by IL-7, and expression levels of Bcl-2 and Bax, showed that only IL-7 responsiveness has an independent impact on early cytoreduction (P <. 05), thus indicating a potential prognostic relevance of IL-7 sensitivity in T-ALL.

Detection of acute leukemia cells with mixed lineage leukemia (MLL) gene rearrangements by flow cytometry using monoclonal antibody 7.1

Translocations involving 11q23 are among the most common genetic abnormalities in hematologic malignancies, occurring in approximately 5-10% of acute lymphoblastic leukemia (ALL) and 5% of acute myeloblastic leukemia (AML). In 11q23 translocations, the mixed lineage leukemia (MLL) gene on chromosome 11, band q23, is usually disrupted. The human homologue of the rat NG2 chondroitin sulfate proteoglycan molecule, as detected by the monoclonal antibody (moab) 7.1, was shown to be expressed on leukemic cells with MLL rearrangements of children with acute leukemia. We further investigated the reactivity of the moab 7.1 on 533 cell samples of adults (n = 215) and children (n = 318) with acute leukemias (271 AML, 217 B-lineage ALL, 37 T-lineage ALL, eight CD7+ CD56+ myeloid/natural killer cell precursor acute leukemias) by flow cytometry. In AML, 38 samples were positive for moab 7.1 ('20%-cut-off-level'). These moab 7.1-positive AML cases revealed a myelomonocytic-differentiated immunophenotype with coexpression of the NK cell marker CD56 in 33 of 38 cases. Two of eight cell samples of the recently described CD7+ CD56+ myeloid/natural killer cell precursor acute leukemia entity reacted with moab 7.1. In ALL, 35 samples mostly of the pro-B-ALL subtype (33 pro-B-ALL, one common-ALL, one pre-B-ALL) were positive for moab 7.1. 58 (81%) of 72 samples with MLL rearrangements were positive for moab 7.1 including 28/31 with a t(4;11), 16/17 with a t(9;11), 3/5 with a t(11;19), and 2/6 with a del(11)(q23). All moab 7.1-positive ALL (n = 34) and childhood AML (n = 17) cases revealed MLL rearrangements as detected by Southern blot analysis and RT-PCR. However, 11 adults with AML, and one adult with moab 7.1-positive CD7+ CD56+ myeloid/natural killer cell precursor acute leukemia were negative for MLL rearrangements as proved by Southern blot analysis. We conclude that moab 7.1 is a sensitive but not entirely specific marker for the identification of 11q23-associated AML and ALL by flow cytometry in children and adults.

Clinical significance of P-glycoprotein expression and function for response to induction chemotherapy, relapse rate and overall survival in acute leukemia

BACKGROUND AND OBJECTIVES

A multidrug-resistance (MDR) phenotype mediated by P-glycoprotein (P-gp) contributes to chemotherapy failure in acute leukemia. However, the exact prognostic significance of this resistance mechanism is still unclear, mostly due to methodologic problems in P-gp detection. We therefore investigated, whether P-gp expression levels or functional P-gp activity better predict response to induction chemotherapy, relapse rate and overall survival in acute leukemia.

DESIGN AND METHODS

We examined cell samples of 121 adults with de novo acute myeloid leukemia (AML) and 102 children with newly diagnosed acute lymphoblastic leukemia (ALL) for P-gp expression and functional P-gp activity by flow cytometry. P-gp function was determined by the rhodamine 123 (rh123)-efflux test (AML n=121, ALL n=102) and P-gp expression levels using the P-gp specific monoclonal antibodies (moabs) MRK-16 (AML n=51, ALL n=31), 4.E3 (AML n=35, ALL n=32), or UIC-2 (AML n=68, ALL n=50). We correlated our findings with the immunophenotype, FAB morphology, cytogenetics and clinical data of the examined patients.

RESULTS

P-gp expression levels as detected by MRK-16 and 4.E3 were very low and did not differ between AML and ALL as estimated using relative fluorescence intensity (RFI) values and D-values by Kolmogorow-Smirnov (KS) statistics. For moab UIC-2, P-gp expression levels were higher in AML than in ALL. Within AML, moab UIC-2 mainly reacted with myelomonocytic-differentiated leukemic cells of the FAB M4/5 subtypes. No correlation between P-gp expression levels as detected by MRK-16, 4.E3 or UIC-2 and the response to induction chemotherapy or relapse rate, both in AML and ALL, was observed. However, a prognostic impact of P-gp expression levels on overall survival in AML was seen for moab MRK-16. Moreover, within AML, P-gp function was higher in immature blast cells as defined by immunophenotype and FAB morphology and correlated with response to induction chemotherapy, relapse rate, overall survival as well as cytogenetic risk groups. In ALL, the overall functional P-gp activity was lower than in AML and did not correlate with immunophenotypical subgroups, response to induction chemotherapy, relapse rate or overall survival.

INTERPRETATION AND CONCLUSIONS

Our data demonstrate a prognostic impact of P-gp in AML but not ALL and indicate that the functional rh123-efflux assay should be preferred for flow-cytometric P-gp evaluation in acute leukemia compared with P-gp expression analysis by monoclonal antibodies.

Constitutive expression levels of CD95 and Bcl-2 as well as CD95 function and spontaneous apoptosis in vitro do not predict the response to induction chemotherapy and relapse rate in childhood acute lymphoblastic leukaemia

CD95 (Fas/APO-1) expression and function and Bcl-2 expression, as well as spontaneous apoptosis in vitro, have been shown to be predictive markers for the in vivo response to chemotherapy in acute myeloid leukaemia (AML). To determine the clinical significance of apoptosis-regulating factors in acute lymphoblastic leukaemia (ALL), we investigated cell samples of children with ALL who had been included in the German ALL Berlin-Frankfurt-Münster (BFM) study using flow cytometry for constitutive expression levels of CD95 (n = 110) and Bcl-2 (n = 110). Furthermore, we determined the extent of spontaneous apoptosis in vitro (n = 102) and susceptibility to anti-CD95-induced apoptosis (CD95-sensitivity) (n = 97). We correlated these findings with the functional activity of the multidrug resistance (MDR)-associated P-glycoprotein (P-gp), as detected by the rhodamine123 efflux test, immunophenotype, cytogenetics and clinical data of the patients examined. Good responders to initial prednisone therapy ('prednisone response') revealed significantly higher Bcl-2 expression levels [5.4 +/- 3.4 relative fluorescence intensity (RFI), n = 68] than poor responders (3.7 +/- 2.6 RFI, n = 42; P = 0.002). There was no significant correlation between the other investigated parameters and prednisone response. Moreover, neither the CD95 and Bcl-2 expression levels nor the extent of spontaneous apoptosis in vitro, CD95 sensitivity or P-gp function were correlated with the response to induction chemotherapy or relapse rate, either for B-cell precursor ALL or T-cell ALL. No consistent pattern of change in CD95 (n = 10) and Bcl-2 expression (n = 9) was noted in cases studied at both initial diagnosis and relapse. In conclusion, our findings underline the different cell biological features of primary AML and ALL cells.

Mitochondrial DNA deletions in cardiomyopathies

Structural changes in the mitochondrial DNA (mtDNA) have been implicated in the pathogenesis of a number of diseases. In this study we report on deletions in the mtDNA of patients with dilated cardiomyopathy (DCM) and post mortem control samples. Total DNA was extracted from left ventricular tissue and nearly the whole mtDNA was amplified using the long PCR technique. For quantitative analysis of the PCR-products with mtDNA deletions the fragments were scanned by a laser densitometer. With the method of long PCR we could detect wild-type and deleted mtDNA in 1 reaction. A total of 14 different deletions ranging from 3.3 to 12.6 kb could be detected. The highest rate of deleted as compared to wild-type mtDNA was 12% in 1 control and 9% in a patient with dilated cardiomyopathy. The number of mitochondrial deletions increase with age in the control group. Additional deletions appear sooner in cardiomyopathic hearts than in control hearts. With regard to the low quantity of the deleted mtDNA and the cumulative nature of these deletions by ageing, we conclude that they may be relevant in individual cases only. A general pathogenic effect on the development of dilated cardiomyopathy is less likely. The mutations may be a sign of increasing stress to the heart, however, thus promoting consecutive damage of mtDNA by initiating a vicious circle.

Clinical significance of CD95, Bcl-2 and Bax expression and CD95 function in adult de novo acute myeloid leukemia in context of P-glycoprotein function, maturation stage, and cytogenetics

Resistance to chemotherapy-induced apoptosis and a multidrug-resistance (MDR) phenotype, mainly mediated by P-glycoprotein (P-gp), contribute to chemotherapy failure in hematologic malignancies. To study apoptosis-regulating factors in acute myeloid leukemia (AML), we investigated cell samples of adults with de novo AML by flow cytometry for constitutive expression levels of the apoptosis-related molecules CD95 (n = 135), Bcl-2 (n = 131), and Bax (n = 66), as well as spontaneous apoptosis in vitro (n = 104) and susceptibility to anti-CD95-induced apoptosis (CD95 sensitivity) (n = 93). We correlated these findings with P-gp function as detected by the rhodamine123-efflux test (n = 121), immunophenotype, FAB morphology, cytogenetics, and clinical data of the examined patients. Immature FAB M0/1 AML cells expressed significantly more Bcl-2 (P < 0.0002) and less CD95 (P < 0.0003) compared with AML cells of the more mature FAB M2-5 subtypes. No maturation-dependent difference in Bax expression was observed. FAB M2-5 AML cells were more susceptible to anti-CD95-induced apoptosis (P < 0.008) and showed a lower P-gp function (P < 0.002) than FAB M0/1 AML cells. Leukemic cells of AML patients who achieved a complete remission (CR) after induction chemotherapy expressed less Bcl-2 than non-responder (NR) (69 CR, 23 NR; P = 0.05). CR was associated with a higher extent of spontaneous apoptosis in vitro (58 CR, 17 NR; P=0.05) and a tendency towards a higher CD95 expression (73 CR, 23 NR; P = 0.08) compared to NR. CR also correlated with a low P-gp function (70 CR, 21 NR; P = 0.008) and a tendency towards CD34 negativity (73 CR, 23 NR; P = 0.08). No correlation between Bax expression and response to induction chemotherapy (49 CR, 12 NR) was observed. In stepwise logistic regression analyses, P-gp function and the extent of spontaneous apoptosis in vitro as well as CD95 sensitivity but not Bcl-2, CD95, Bax, and CD34 expression levels emerged as significant markers for response to induction chemotherapy. We conclude that the constitutive expression of CD95 and Bcl-2, as well as CD95 sensitivity and P-gp function but not constitutive Bax expression depend on the maturation stage of leukemic cells in adult de novo AML. P-gp function, the extent of spontaneous apoptosis in vitro and CD95 sensitivity are more predictive for response to induction chemotherapy in adult de novoAML than the constitutive expression levels of the apoptosis-related molecules CD95, Bcl-2 and Bax.

[Fibrolipomatous hamartoma of the nerve--a rare etiology of macrodactyly. A case report]

Fibrolipomatous hamartoma of nerve is a rare, tumor-like fibro-fatty growth arising from the epi- and perineurium. It mainly affects peripheral nerves and the median nerve in particular. An association with Klippel-Trenaunay syndrome and macrodactyly has been described. We present a 30-year-old patient, in whom the diagnosis of Klippel-Trenaunay syndrome had been made at the age of two, based on macrodactyly of the right hand. Because of increasing functional limitation and pain, the patient was referred to our department, after angiographic exclusion of Klippel-Trenaunay syndrome, for operative reduction of the tumor. Histologic examination revealed a fibrolipomatous hamartoma of the nerve. Further treatment consisted of surgical tumor reduction, which resulted in satisfactory recovery of function in the right hand. After eight months follow-up, the patient was able to perform all normal daily activities, and there was no evidence of recurrence of the lesion. Diagnostic evaluation of macrodactyly is necessary, since there may be an underlying cause such as fibrolipomatous hamartoma of a nerve, which if corrected early by surgical excision may prevent long-term disability.

Differential CD95 expression and function in T and B lineage acute lymphoblastic leukemia cells

CD95 (Fas/APO-1) is a cell surface receptor able to trigger apoptosis in a variety of cell types. The expression and function of the CD95 antigen on leukemic blasts from 42 patients with B lineage and 53 patients with T lineage acute lymphoblastic leukemia (ALL) were investigated using immunofluorescence staining and apoptosis assays. The CD95 surface antigen was expressed in most ALL cases, with the T lineage ALL usually showing a higher intensity of surface CD95 expression as compared with the B lineage ALL cells (relative fluorescence intensity, RFI: 4.8 +/- 0.47 vs 2.2 +/- 0.23, respectively, P < 0.01). Functional studies disclosed that upon oligomerization by anti-CD95 monoclonal antibodies the CD95 protein was either not able to initiate apoptosis of leukemic cells (75% of cases) or induced low rates of apoptosis (20% of cases). Only in 5% of cases did the apoptosis rate exceed the 20% level of the CD95-specific apoptosis. Most of the CD95-sensitive cases were found among T lineage ALLs (38% of T lineage vs 10% of B lineage ALLs). Overall, the extent of CD95-induced apoptosis did not correlate with the expression level of CD95. Similarly, no significant correlation between expression level and functionality of CD95 in human leukemia cell lines of B and T cell origin could be observed. Bcl-2 protein has been associated with prolonged cell survival and has been shown to block partially CD95-mediated apoptosis, but for ALL cells no correlation between bcl-2 expression and spontaneous or CD95-mediated apoptosis could be found. The results obtained in this study indicate that, despite constitutive expression of CD95, the ALL cells are mainly resistant to CD95-triggering. More detailed investigations of the molecular mechanisms involved in the intracellular apoptotic signal transduction, such as interactions of the bcl-2 and the other members of the bcl-2 family, and functionality of the interleukin-1beta converting enzyme (ICE) like-proteases, may give new insights into key events responsible for the resistance or sensitivity to the induction of apoptosis in acute leukemia.

Mechanismen immunologisch vermittelter kardialer Funktionsstörung bei Myokarditis und dilatativer Kardiomyopathie

Humorale und zelluläre Effektormechanismen des Immunsy-stems können über multiple Interaktionen passagere oder per-manente Änderungen der systolischen und diastolischen Myo-kardfunktion hervorrufen. Dies kann über molekulare, metabo-lische, rezeptormediierte und ebenso auch strukturelle Verän-derungen am Myozyten (z.B. Hypertrophie), am Interstitium und an der extrazellulären Matrix (z.B. Fibrose) und der Zellularität (z.B. Myokarditis) erfolgen. In dieser Übersicht liegt der Schwerpunkt der Beschreibung solcher Veränderun-gen beim Krankheitsbild der entzündlichen Herzmuskelerkran-kungen und bei den Pathomechanismen, über die Viren, zyto-toxische T-Zellen, Zytokine und antikardiale Antiköφer in tierexperimentellen Untersuchungen und beim Menschen diese funktionellen und strukturellen Vorgänge beeinflussen.

Left ventricular haemodynamics in murine viral myocarditis

In susceptible DBA/2 mice infection with coxsackievirus B3 leads to severe inflammatory and necrotic lesions in the heart. There is a temporal discrepancy of peak concentrations of replicative virus in the heart and maximal cardiac inflammation. Aims of this study were, first, to determine whether haemodynamic changes occur in coxsackievirus B3-induced murine myocarditis and, second, the time frame in which those alterations may be apparent. By puncture of the left ventricle, pressures and the first derivative dp/dt as parameters of left ventricular function could be obtained on several days of the infection. Haematoxylin-eosin stains of cross-sections of the heart showed the course of inflammatory lesions in the heart; a plaque forming assay assessed virus titres in the heart. Cardiac concentrations of replicative virus peaked on day 3, inflammatory lesions in the heart were maximal on day 7. Left ventricular function was almost preserved until day 5 of the infection, then dropped significantly until day 10. The study suggests that either a cumulative virus-mediated destruction of the myofibres or virally triggered immune reactions to heart cells lead to impairment of left ventricular function.

Coxsackievirus B3 infection leads to cell death of cardiac myocytes

In order to address the question whether the virus or immune reactions to the heart induce cardiac damage in the murine model of coxsackievirus B3 induced myocarditis, calcium-resistant cardiac myocytes of a myocarditis susceptible strain of mice were isolated and exposed to myocarditic coxsackievirus B3. The tetrazolium salt MTT was used to visualize the effect of the virus upon cell viability by inverse light microscopy and by an EA test. Coxsackievirus B3 infected isolated adult cardiac myocytes as well as infected cultured cardiac fibroblasts were examined. In vitro the virus killed the myocytes within 16 h of infection whereas the fibroblasts survived the infection. Since coxsackievirus B3 is able to kill cardiac myocytes by itself, immunosuppressive treatment of acute coxsackievirus B3 induced myocarditis may be harmful by eliminating host immune defence mechanisms and, therefore, may lead to an enhanced viral spread and virus induced myocyte necrosis in the heart.