Treatment of Dissecting Vertebral Pseudoaneurysms: A Single-Center Experience.

Background: Dissecting vertebral artery pseudoaneurysms represent a unique clinical challenge with careful appreciation for location of the posterior inferior cerebellar artery. Limited data is available in terms of outcomes regarding the various treatment modalities. Methods: 11 patients with dissecting pseudoaneurysms were identified from 2013-2021. Pseudoaneurysm size and morphology, clinical presentation, and treatment approach was collected. Success of treatment was recorded based on post-operative imaging as well as documented overall patient outcomes. Three primary treatment modalities emerged: coil embolization, stent assisted coiling, and flow diversion. Results: Of the 11 patients, 5 were female and 6 were male with an age from 36 to 69.7. 7 had ruptured pseudoaneurysms at time of treatment. Size of pseudoaneurysm ranged from 3 to 6 mm. 8 were on the right and 3 were on the left vertebral artery. 8 were proximal to PICA and 3 were distal. Co-dominance of vertebral filling was seen in 5 patients, 5 with dominance through right vertebral artery, and 1 with dominance through left vertebral artery. Variability existed in treatment approaches with 4 patients undergoing coil occlusion, 5 patients undergoing flow diversion stenting, and 2 patients undergoing flow diversion stenting with jailed coiling. 1 patient had enlargement of pseudoaneurysm while inpatient and required a second flow diversion device. 1 patient had two flow diversion devices placed initially at time of treatment due to morphology of PA. 6 patients had repeat angiograms between 6 to 9 months with complete occlusion. 3 had CTA or MRA with complete occlusion for those that had flow diversion, they were transitioned from aspirin and clopidogrel to aspirin monotherapy after first repeat angiogram. 6 patients required shunt placement for hydrocephalus. 1 patient died prior to discharge due to sepsis. 2 patients died post discharge: 1 with myocardial infarction and the 2nd due to urosepsis.Dissecting vertebral pseudoaneurysm has high morbidity and mortality if rupture occurs. Location of PICA origin influences treatment approach. Patients with poor Hunt/Hess scores upon arrival had increased risk for systemic infection and mortality.

[Therapy of chronic hepatitis B and C virus infections in the clinical practice]. / Therapie der chronischen Hepatitis B und C in der Praxis.

Approximately 550 million people worldwide are chronically infected with hepatitis B (HBV) or hepatitis C (HCV) virus. The clinical course of HBV and HCV infection is variable and can lead to a chronic but mild hepatitis or to liver cirrhosis and hepatocellular carcinoma (HCC)1. Therefore, antiviral therapy should be considered in patients with chronic hepatitis to prevent progression of disease. Here, we review the current indications and guidelines for antiviral therapy in chronic HBV and HCV infection.

Iloprost has potent anti-inflammatory properties on human monocyte-derived dendritic cells.

BACKGROUND: The stable prostaglandin I2 analogue (iloprost) iloprost has been shown to inhibit allergic airway inflammation in mice by modulating the function of myeloid dendritic cells (DCs). OBJECTIVE: The aim of the current study was to investigate the biological activity of iloprost on human monocyte-derived DCs. METHODS: I prostanoid (IP) receptor expression was analysed by RT-PCR. Cytokine secretion by DCs and CD4+ T cells was measured by ELISA. The expression of the transcription factor FoxP3 after co-culture of DCs with CD4+ CD45RA+ T cells was analysed by flow cytometry. RESULTS: Human monocyte-derived DCs were found to express mRNA specific for the PGI2 receptor IP, and stimulation with iloprost resulted in increased cyclic AMP levels in both immature DCs (iDCs) and mature DCs (mDCs). Moreover, iloprost dose dependently inhibited the secretion of TNF-alpha, IL-6, IL-8 and IL-12p70 in mDCs, while it enhanced IL-10 production. Changes in cytokine secretion were paralleled by an altered T-cell priming capacity of DCs: in co-culture experiments of iloprost-treated mDC and naïve CD45RA+ T cells, an induction of regulatory T cells could be observed, as demonstrated by increased intracellular FoxP3 expression and IL-10 production. Additionally, iloprost inhibited the MIP-3beta-induced migration of mDCs. CONCLUSION: In summary, our results provide evidence that iloprost profoundly affects the function of human myeloid DCs. Therefore, iloprost might also be a new therapeutical option for the treatment of asthma in humans.

[Liver diseases in pregnancy]. / Lebererkrankungen in der Schwangerschaft.

Abnormal liver function tests occur in 3 - 5% of pregnancies for different reasons. Apart from pre-existing liver diseases liver diseases occurring during pregnancy, such as gall stones or viral hepatitis, most liver dysfunctions in pregnancy are caused by one of the five pregnancy-related liver diseases. The five known pregnancy-related liver diseases can be classified in two main categories depending on their association with or without preeclampsia. The preeclampsia-associated liver diseases are the preeclampsia itself, the HELLP-syndrome ("Hemolysis" (H), "Elevated Liver Tests" (EL), "Low Platelet Count" (LP)) and the acute fatty liver of pregnancy. Hyperemesis gravidarum and intrahepatic cholestasis of pregnancy are not associated with preeclampsia. Hyperemesis gravidarum is characterised by intractable vomiting in the first trimester of pregnancy. 50% of patients with this condition have liver dysfunction. Intrahepatic cholestasis of pregnancy presents with pruritus and elevated bile acids in the second half of pregnancy. Patients have often mild jaundice and highly elevated liver enzymes. Treatment of choice is ursodeoxycholic acid to relieve the mother's symptoms. With this condition mainly the fetus is at risk. Severe preeclampsia is the most common cause of liver dysfunction in pregnancy, and is in some cases further complicated by HELLP syndrome. The prompt delivery of the baby is the only definitive therapy. However, many life-threatening maternal complications like liver hematoma or rupture and abruptio placentae can occur. Acute fatty liver of pregnancy is also a severe illness occuring mostly in the third trimester; microvesicular fat deposition in the liver can cause liver failure with coagulopathy and encephalopathy. Only the immediate delivery of the fetus can save mother and child.

[Jaundice in an HIV-positive pregnant woman]. / Ikterus bei einer HIV-positiven Schwangeren.

HISTORY AND CLINICAL FINDINGS: A 32-year-old woman of African origin in the third trimester of pregnancy was admitted to our hospital with jaundice, dark urine and mild abdominal pain. Symptoms had started one week before admission. During a routine pregnancy check-up six months previously, an HIV infection had been diagnosed and antiretroviral therapy was initiated. The patient had moved from Nigeria to Germany two years before and has not been abroad since then. INVESTIGATIONS: Physical examination revealed marked scleral jaundice and a mild tenderness in the right upper abdominal quadrant. The laboratory tests showed highly elevated levels of liver enzymes and bilirubin. Ultrasonography of the abdomen indicated normal liver size and parenchyma. DIAGNOSIS, THERAPY AND CLINICAL COURSE: A hepatitis E virus (HEV) infection was identified as the cause of the acute hepatitis. Within the next few weeks the patient recovered spontaneously und a healthy boy was delivered by cesarean section at the expected date. CONCLUSIONS: In acute hepatitis during pregnancy concomitant or newly acquired liver diseases such as viral hepatitis should be considered, once ultrasound has excluded obstructive cholestasis or acute cholecystitis.

Modulation of P2X7 receptor functions by polymyxin B: crucial role of the hydrophobic tail of the antibiotic molecule.

BACKGROUND AND PURPOSE: P2X7 is a membrane receptor for extracellular ATP which is highly expressed in dendritic cells, macrophages and microglia where it mediates pro-inflammatory responses. The antibiotic polymyxin B, which binds to and neutralizes the toxic residue of bacterial lipopolysaccharide, greatly amplifies cellular responses mediated by the P2X7 receptor. However, the molecular mechanism involved is so far unknown. EXPERIMENTAL APPROACH: We investigated the effects of polymyxin B and polymyxin B nonapeptide (PMBN) which is the deacylated amino derivative of polymyxin B lacking the N-terminal fatty amino acid 6-methylheptanoic/octanoic-Dab residue, in human macrophages and HEK293 cells stably expressing the human P2X7 receptor (HEK293-hP2X7). Differences between the two antibiotics were assessed by monitoring the following: nucleotide-induced cytoplasmic free Ca2+ concentration changes, plasma membrane permeability changes, lactate dehydrogenase activity, cell morphology changes. Western blot and microscopic analyses of P2X7GFP-expressing cells were also performed. KEY RESULTS: In contrast to polymyxin B, the polymyxin B nonapeptide was unable to potentiate: a) the ATP-induced Ca2+ increase, b) pore formation and consequently ATP-mediated plasma membrane permeabilization; c) ATP-dependent cytotoxicity. Moreover, in contrast to polymyxin B, polymyxin B nonapeptide did not affect aggregation of the P2X7 receptor subunits and it did not potentiate P2X7-dependent cell fusion. CONCLUSIONS AND IMPLICATIONS: The effects of polymyxin B depended on the presence of its N-terminal fatty amino acid 6-methylheptanoic/octanoic-Dab residue as deletion of this residue abolished polymyxin B-dependent modulation of ATP-triggered responses. These findings are important in the search for allosteric modulators of the P2X7 receptor.

[The role of the virus specific T-cell response in acute and chronic HBV and HCV infection]. / Die Rolle der virusspezifischen T-Zellantwort bei der akuten und chronischen Hepatitis-B- und -C-Virusinfektion.

Infections with hepatitis B (HBV) and hepatitis C virus (HCV) are worldwide one of the most frequent causes for chronic liver disease, liver cirrhosis and hepatocellular carcinoma. The mechanisms responsible for the elimination or the persistence of the virus are not well understood. The immunopathogenesis of HBV and HCV infection is primarily mediated by virus specific CD4+- and CD8+-T-cells. During acute infection a strong and multispecific T-cell response against different viral epitopes can be detected and is associated with the clearance of the virus. In case of viral persistence virus specific T-cells contribute to liver inflammation. In this article we summarize the current concepts about the role of the virus specific T-cell response in acute and chronic HBV and HCV infection.

Elevated expression of extracellular matrix metalloproteinase inducer (CD147) and membrane-type matrix metalloproteinases in venous leg ulcers.

BACKGROUND: Matrix metalloproteinases (MMPs) contribute to matrix remodelling in venous leg ulcers. Extracellular MMP inducer (EMMPRIN; CD147) has been reported to increase MMP expression, and membrane type 1 MMP (MT1-MMP) has been implicated in the activation of MMPs. OBJECTIVES: To examine whether and to what degree EMMPRIN, MMP-2, MT1-MMP and membrane type 2 MMP (MT2-MMP) are expressed in venous leg ulcers as well as the association with MMP activity. METHODS: EMMPRIN, MMP-2, MT1-MMP and MT2-MMP were analysed by zymography and immunohistochemistry in biopsies from healthy skin and lesional tissue from venous leg ulcers. RESULTS: Zymography provided direct evidence of increased proteolytic activity of MMP-2 in lesional skin in comparison with healthy controls. Immunostaining showed intense expression of EMMPRIN, MMP-2, MT1-MMP and MT2-MMP in dermal structures of venous leg ulcers, whereas only EMMPRIN and MMP-2 showed elevated expression in perivascular regions. Our findings indicate that venous leg ulcers are characterized by elevated expression of EMMPRIN, MMP-2, MT1-MMP and MT2-MMP. The immunohistological findings of skin alterations reflect the dynamic process of activation of soluble and membrane-bound MMPs, which may be highly induced by EMMPRIN. CONCLUSIONS: These data suggest for the first time that membrane-bound MMPs may favour enhanced turnover of the extracellular matrix and support unrestrained MMP activity in venous leg ulcers.

Expression and function of adenosine receptors in human dendritic cells.

Dendritic cells (DCs) are specialized antigen-presenting cells characterized by their ability to migrate into target sites, process antigens, and activate naive T cells. In this study, we analyzed the biological activity and intracellular signaling of adenosine by using reverse transcriptase-polymerase chain reaction assays to investigate mRNA expression of A(1), A(2a) and A(3) adenosine receptors in immature and mature human DCs. Functional experiments on adenosine stimulation showed chemotaxis, intracellular calcium transients, and actin polymerization, but no activation of adenylate cyclase in immature DCs. Experiments with receptor isotype-selective agonists and antagonists as well as pertussis toxin revealed that chemotaxis, calcium transients, and actin polymerization were mediated via G(i-) or G(0-)protein-coupled A(1) and A(3) receptors. Maturation of DCs induced by lipopolysaccharide (LPS) resulted in down-regulation of A(1) and A(3) receptor mRNAs, although A(2a) receptor mRNA was still expressed. However, in LPS-differentiated DCs, adenosine and an A(2a) receptor agonist stimulated adenylate cyclase activity, enhanced intracellular cAMP levels, and inhibited interleukin 12 (IL-12) production. These effects could be completely prevented by pretreatment with A(2) receptor antagonist. These findings strongly suggest that adenosine has important but distinct biological effects in DCs activity as a chemotaxin for immature DCs and as a modulator of IL-12 production in mature DCs. These effects can be explained by differential expression of adenosine receptor subtypes.

Functional characterization of P2Y and P2X receptors in human eosinophils.

Activation of purinoceptor by ATP induces in eosinophils various cell responses including calcium transients, actin polymerization, production of reactive oxygen metabolites, CD11b-expression, and chemotaxis. Here, the effect of ion channel-gated P2X and/or G protein-coupled P2Y receptor agonists ATP, ATPgammaS, alpha,beta-meATP, 2-MeSATP, BzATP, ADP, CTP, and UTP on the intracellular Ca(2+)-mobilization, actin polymerization, production of reactive oxygen metabolites, CD11b expression and chemotaxis of human eosinophils were measured and the biological activity was analyzed. Although all tested nucleotides were able to induce all these cell responses, the biological activity of the analyzed nucleotides were distinct. Agonists of the G protein-coupled P2Y receptors such as 2-MeSATP, UTP, and ADP have a higher biological activity for production of reactive oxygen metabolites, actin polymerization and chemotaxis in comparison to the ion channel-gated P2X agonists alphabeta-meATP, BzATP, and CTP. In contrast, P2Y and P2X agonist showed similar potencies in respect to intracellular calcium transient and CD11b up-regulation. This conclusion was further supported by experiments with receptor iso-type antagonist KN62, EGTA or with the G(i) protein-inactivating pertussis toxin. These findings indicate participation of different purinorecptors in the regulation of cell responses in eosinophils.

Downregulation of platelet-activating factor responsiveness during maturation of human dendritic cells.

Dendritic cells (DCs) are specialized antigen-presenting cells characterized by their ability to migrate into target sites, process antigens, and activate naive T-cells. Biological activities of platelet-activating factor (PAF) and the cytokine macrophage inflammatory protein-3beta (MIP-3beta) as well as the mRNA expression of their receptors were characterized in human DCs during lipopolysaccharide (LPS)-promoted maturation. Platelet-activating factor induced calcium transients, migration-associated actin polymerization response, and chemotaxis in immature human dendritic cells differentiated in vitro from monocytes with interleukin-4 and granulocyte macrophage colony stimulating factor. In addition, RT-PCR experiments indicated mRNA expression of the PAF receptor in these immature DCs. Cell studies and mRNA analyses further revealed that immature DCs neither respond to MIP-3beta nor express its specific receptor, CCR7. Induction of cell differentiation by LPS led to the loss of the mRNA expression of the PAF receptor, accompanied by decreasing intracellular calcium release, actin polymerization, and migration after stimulation with PAF. In contrast, LPS treatment induced increasing responsiveness toward MIP-3beta and mRNA expression of CCR7. Comparable data regarding mRNA expression of PAF receptor and PAF responsiveness were also obtained with another maturation protocol using TNFalpha instead of LPS. The direct comparison between the two different protocols showed a slower decrease of PAF responsiveness induced by TNFalpha than by LPS. These results show the loss of PAF responsiveness associated with downregulation of PAF receptor mRNA expression during LPS- and TNFalpha-induced maturation in human DCs. Therefore, these findings point to a functional relevance of PAF in recruiting immature DCs, whereas MIP-3beta might regulate the migration of DCs at a later stage of maturation.