Effects of Thoratec pulsatile ventricular assist device (PVAD) timing on the abdominal aortic wave intensity pattern

Arterial waves are seen as possible independent mediators of cardiovascular risks, and the wave intensity analysis (WIA) has therefore been proposed as a method for patient selection for ventricular assist device (VAD) implantation. Interpreting measured wave intensity (WI) is challenging and complexity is increased by the implantation of a VAD. The waves generated by the VAD interact with the waves generated by the native heart, and this interaction varies with changing VAD settings. Eight sheep were implanted with a pulsatile VAD (PVAD) through ventriculo-aortic cannulation. The start of PVAD ejection was synchronized to the native R-wave and delayed between 0 % - 90 % of the cardiac cycle in 10 % steps or phase shifts (PS). Pressure and velocity signals were registered, using a combined Doppler and pressure wire positioned in the abdominal aorta, and used to calculate the WI. Depending on the PS, different wave interference phenomena occurred. Maximum unloading of the left ventricle (LV) coincided with constructive interference and maximum blood flow pulsatility, and maximum loading of the LV coincided with destructive interference and minimum blood flow pulsatility. We believe, that non-invasive WIA could potentially be used clinically to assess the mechanical load of the LV, and to monitor the peripheral hemodynamics such as blood flow pulsatility and risk of intestinal bleeding.

Incomplete Distal Renal Tubular Acidosis from a Heterozygous Mutation of the V-ATPase B1 Subunit

Congenital distal renal tubular acidosis (dRTA) from mutations of the B1 subunit of the V-ATPase is considered an autosomal recessive disease. We analyzed a dRTA kindred with a truncation-mutation of B1 (p.Phe468fsX487) previously shown to have failure of assembly into the V1 domain of the V-ATPase. All heterozygous carriers in this kindred have normal plasma bicarbonate concentrations, thus evaded the diagnosis of RTA. However, inappropriately high urine pH, hypocitraturia, and hypercalciuria are present either individually or in combination in the heterozygotes at baseline. Two of the heterozygotes studied also have inappropriate urinary acidification with acute ammonium chloride loading and impaired urine-blood pCO2 gradient during bicarbonaturia indicating presence of H+ gradient and flux defects. In normal human renal papillae, wild type B1 is located primarily on the plasma membrane but papilla from one of the heterozygote who had kidney stones had renal tissue secured from surgery showed B1 in both plasma membrane as well as a diffuse intracellular staining. Titrating increasing amounts of the mutant B1 subunit did not exhibit negative dominance over the expression, cellular distribution, or H+-pump activity of the wild type B1 in mammalian HEK293 cells and in V-ATPase-deficient S. cerevisiae. This is the first demonstration of renal acidification defects and nephrolithiasis in heterozygous carriers of mutant B1 subunit; which cannot be attributable to negative dominance. We propose that heterozygosity may lead to mild real acidification defects due to haploinsufficiency. B1 heterozygosity should be considered in patients with calcium nephrolithiasis and urinary abnormalities such as alkalinuria or hypocitraturia.

Suitability of Common Collagen Scaffolds for Anterior Cruciate Ligament Repair

Introduction: Anterior cruciate ligament (ACL) injuries are very common; in Germany incidence of ACL ruptures is estimated at 32 per 100 000 in the general population and in the sports community this rate more than doubles. Current gold standard for anterior cruciate lig- ament repair is reconstruction using an autograft [1]. However, this approach has shown some limitations. A new method has been her- alded by the Knee Team at the Bern University Hospital (Inselspital) and the Sonnenhof clinic called Dynamic Intraligamentary Stabilization (DIS), which keeps ACL remnants in place in order to promote biologi- cal healing and makes use of a dynamic screw system [2]. The aim of this study was to investigate the cytocompatibility of collagen patches in combination with DIS to support regeneration of the ACL. The spe- cific hypothesis we tested was whether MSCs would differentiate towards TCs in co-culture. Materials and methods: Primary Tenocytes (TCs) and human bone marrow derived mesenchymal stem cells (MSCs) were harvested from ACL removed during knee prothesis or from bone marrow aspirations (Ethical Permit 187/10). Cells were seeded on two types of three dimensional carriers currently approved for cartilage repair, Novocart (NC, B. Brown) and Chondro-Gide (CG, Geistlich). These scaffolds comprise collagen structures with interconnecting pores originally developed for seeding of chondrocytes in the case of CG. ~40k cells were seeded on punched zylindrical cores of 8 mm in Ø and cultured on CG or NC patches for up to 7 days. The cells were either cultured as TC only, MSC only or co-cultured in a 1:1 mix on the scaffolds and on both sides of culture inserts (PET, high density pore Ø 0.4 mm, BD, Fal- con) with cell-cell contact. We monitored DNA content, GAG and HOP-content, tracked the cells using DIL and DIO fluorescent dyes (Molecular Probes, Life technologies) and confocal laser scanning and SEM microscopy as well as RT-PCR of tenocyte specific markers (i.e. col 1 and 3, TNC, TNMD, SCXA&B, and markers of dedifferentiation ACAN, col2, MMP3, MMP13). Finally, H&E stain was interpreted on cryosections and SEM images of cells on the scaffold were taken. Results: ThecLSMimagesshowedcellproliferationoverthe7dayson both matrices, however, on CG there were much fewer MSCs attached than on NC. SEM images showed a roundish chondrocyte-like pheno- type of cells on CG whereas on NC the phenotype was more teno- cyte-like (Fig. 1). Gene expression of both, MSC and TC seem to confirm a more favorable environment in 3D for both patches rather than monolayer control.

Cerebral High-grade Oligodendroglioma with Sarcomatous Transdifferentiation ("Oligosarcoma") in a Boxer Dog.

A 9-year-old Boxer dog was referred to the Veterinary Teaching Hospital of the University of Bern for a history of chronic neck pain and gait problems, which rapidly progressed to a non-ambulatory status. Magnetic resonance imaging (MRI) examination of the head revealed a large intra-axial space-occupying lesion that was divided in two portions interconnected by a thin isthmus at the level of the cerebellar tentorium. Histopathology revealed a biphasic malignant neoplasm composed of neuroepithelial and mesenchymal elements. The former displayed characteristics of conventional anaplastic oligodendroglioma involving brisk mitotic activity and glomeruloid microvascular proliferation on a background of a fibrillary round cells with "honeycomb-like" perinuclear vacuolation. Conversely, the sarcomatous moiety exhibited haphazard fascicles of spindle cells amidst an intricate mesh of pericellular basal lamina and broad bands of collagen. Both tumor cell populations immunoreacted for Olig-2 and – to a lesser extent – GFAP. In addition, the sarcomatous areas focally expressed vimentin, muscular actin, and smooth muscle actin. "Oligosarcoma" - an exquisitely uncommon pattern of oligodendroglial malignancy in humans - has not previously been reported to affect dogs, although oligodendroglioma is a common CNS tumor in this species. Whether canine oligosarcoma shares with its human counterpart not only morphological aspects, but also molecular signatures, clinical behavior and responsiveness to therapy merits further investigation. In humans, oligodendroglial differentiation tends to confer significant clinical advantage with respect to prognosis and adjuvant treatment options. The awareness of such hallmarks and the investigation of their impact on prognosis are crucial for improved therapeutical strategies in dogs.

Inhibition of matrix metalloproteinases attenuates brain damage in experimental meningococcal meningitis.

BackgroundApproximately 7% of survivors from meningococcal meningitis (MM) suffer from neurological sequelae due to brain damage in the course of meningitis. The present study focuses on the role of matrix metalloproteinases (MMPs) in a novel mouse model of MM-induced brain damage.MethodsThe model is based on intracisternal infection of BALB/c mice with a serogroup C Neisseria meningitidis strain. Mice were infected with meningococci and randomised for treatment with the MMP inhibitor batimastat (BB-94) or vehicle. Animal survival, brain injury and host-response biomarkers were assessed 48 h after meningococcal challenge.ResultsMice that received BB-94 presented significantly diminished MMP-9 levels (p¿<¿0.01), intracerebral bleeding (p¿<¿0.01), and blood-brain barrier (BBB) breakdown (p¿<¿0.05) in comparison with untreated animals. In mice suffering from MM, the amount of MMP-9 measured by zymography significantly correlated with both intracerebral haemorrhage (p¿<¿0.01) and BBB disruption (p¿<¿0.05).ConclusionsMMPs significantly contribute to brain damage associated with experimental MM. Inhibition of MMPs reduces intracranial complications in mice suffering from MM, representing a potential adjuvant strategy in MM post-infection sequelae.

The kynurenine pathway is involved in bacterial meningitis.

BackgroundBacterial meningitis (BM) is characterized by an intense host inflammatory reaction, which contributes to the development of brain damage and neuronal sequelae. Activation of the kynurenine (KYN) pathway (KP) has been reported in various neurological diseases as a consequence of inflammation. Previously, the KP was shown to be activated in animal models of BM, and the association of the SNP AADAT¿+¿401C/T (kynurenine aminotransferase II - KAT II) with the host immune response to BM has been described. The aim of this study was to investigate the involvement of the KP during BM in humans by assessing the concentrations of KYN metabolites in the cerebrospinal fluid (CSF) of BM patients and their relationship with the inflammatory response compared to aseptic meningitis (AM) and non-meningitis (NM) groups.MethodsThe concentrations of tryptophan (TRP), KYN, kynurenic acid (KYNA) and anthranilic acid (AA) were assessed by HPLC from CSF samples of patients hospitalized in the Giselda Trigueiro Hospital in Natal (Rio Grande do Norte, Brazil). The KYN/TRP ratio was used as an index of indoleamine 2,3-dioxygenase (IDO) activity, and cytokines were measured using a multiplex cytokine assay. The KYNA level was also analyzed in relation to AADAT¿+¿401C/T genotypes.ResultsIn CSF from patients with BM, elevated levels of KYN, KYNA, AA, IDO activity and cytokines were observed. The cytokines INF-¿ and IL-1Ra showed a positive correlation with IDO activity, and TNF-¿ and IL-10 were positively correlated with KYN and KYNA, respectively. Furthermore, the highest levels of KYNA were associated with the AADAT¿+¿401 C/T variant allele.ConclusionThis study suggests a downward modulatory effect of the KP on CSF inflammation during BM.

Endogenous and synthetic MMP inhibitors in CNS physiopathology.

Matrix metalloproteinases (MMPs, including the membrane-type MMPs (MT-MMPs)), a disintegrin and metalloproteinase (ADAM), and ADAM with thrombospondin motifs belong to the metzincins, a subclass of metalloproteinases that contain a Met residue and a Zn(2+) ion at the catalytic site necessary for enzymatic reaction. MMP proteolytic activity is mainly controlled by their natural tissue inhibitors of metalloproteinase (TIMP). A number of synthetic inhibitors have been developed to control deleterious MMP activity. The roles of MMPs and some of their ECM substrates in CNS physiology and pathology are covered by other chapters of the present volume and will thus not be addressed in depth. This chapter will focus (i) on the endogenous MMP inhibitors in the CNS, (ii) on MMP and TIMP regulations in three large classes of neuropathologic processes (inflammatory, neurodegenerative, and infectious), and (iii) on synthetic inhibitors of MMPs and the perspective of their use in different brain diseases.

A pilot study for targeted surveillance of bovine spongiform encephalopathy in Nigeria.

Bovine spongiform encephalopathy (BSE), popularly known as 'mad cow disease', led to an epidemic in Europe that peaked in the mid-1990s. Its impact on developing countries, such as Nigeria, has not been fully established as information on livestock and surveillance has eluded those in charge of this task. The BSE risk to Nigeria's cattle population currently remains undetermined, which has resulted in international trade restrictions on commodities from the cattle population. This is mainly because of a lack of updated BSE risk assessments and disease surveillance data. To evaluate the feasibility of BSE surveillance in Nigeria, we carried out a pilot study targeting cattle that were presented for emergency or casualty slaughter. In total, 1551 cattle of local breeds, aged 24 months and above were clinically examined. Ataxia, recumbency and other neurological signs were topmost on our list of criteria. A total of 96 cattle, which correspond to 6.2%, presented clinical signs that supported a suspect of BSE. The caudal brainstem tissues of these animals were collected post-mortem and analysed for the disease-specific form of the prion protein using a rapid test approved by the International Animal Health Organization (OIE). None of the samples were positive for BSE. Although our findings do not exclude the presence of BSE in Nigeria, they do demonstrate that targeted sampling of clinically suspected cases of BSE is feasible in developing countries. In addition, these findings point to the possibility of implementing clinical monitoring schemes for BSE and potentially other diseases with grave economic and public health consequences.

MicroRNA profile of poorly differentiated thyroid carcinomas: new diagnostic and prognostic insights.

The diagnosis of conventional and oncocytic poorly differentiated (oPD) thyroid carcinomas is difficult. The aim of this study is to characterise their largely unknown miRNA expression profile and to compare it with well-differentiated thyroid tumours, as well as to identify miRNAs which could potentially serve as diagnostic and prognostic markers. A total of 14 poorly differentiated (PD), 13 oPD, 72 well-differentiated thyroid carcinomas and eight normal thyroid specimens were studied for the expression of 768 miRNAs using PCR-Microarrays. MiRNA expression was different between PD and oPD thyroid carcinomas, demonstrating individual clusters on the clustering analysis. Both tumour types showed upregulation of miR-125a-5p, -15a-3p, -182, -183-3p, -222, -222-5p, and downregulation of miR-130b, -139-5p, -150, -193a-5p, -219-5p, -23b, -451, -455-3p and of miR-886-3p as compared with normal thyroid tissue. In addition, the oPD thyroid carcinomas demonstrated upregulation of miR-221 and miR-885-5p. The difference in expression was also observed between miRNA expression in PD and well-differentiated tumours. The CHAID algorithm allowed the separation of PD from well-differentiated thyroid carcinomas with 73-79% accuracy using miR-23b and miR-150 as a separator. Kaplan-Meier and multivariate analysis showed a significant association with tumour relapses (for miR-23b) and with tumour-specific death (for miR-150) in PD and oPD thyroid carcinomas. MiRNA expression is different in conventional and oPD thyroid carcinomas in comparison with well-differentiated thyroid cancers and can be used for discrimination between these tumour types. The newly identified deregulated miRNAs (miR-150, miR-23b) bear the potential to be used in a clinical setting, delivering prognostic and diagnostic informations.

Investigation of IL-23 (p19, p40) and IL-23R identifies nuclear expression of IL-23 p19 as a favorable prognostic factor in colorectal cancer: a retrospective multicenter study of 675 patients.

IL-23 is a heterodimeric cytokine involved in inflammatory diseases; its role in cancer progression is controversial. Here we analyse the expression of IL-23 subunits (p40 and p19) and IL-23R in colorectal cancer with regard to disease progression, clinical-pathological and molecular aspects. Immunohistochemistry for IL-23p19, IL-23p40, IL-23R and CD8 was performed on a multi-punch tissue microarray of 195 colorectal cancers (cohort 1), matched normal tissue, adenoma and lymph node metastases. Results were compared with clinical-pathological features and CD8+ T-cell counts, then validated on two patient cohorts (cohort 2: n=341, cohort 3: n=139). Cytoplasmic/membranous expression of IL-23 (p19 and p40 subunits) and IL-23R, respectively were over-expressed in carcinomas versus adenomas and normal tissues (p<0.0001) but were reduced in lymph node metastases (p<0.0001). Nuclear IL-23p19 expression was observed in 23.1% and was associated with early TNM stage (p=0.0186), absence of venous (p=0.0124) and lymphatic invasion (p=0.01493), favorable survival (p=0.014) and absence of distant metastasis (p=0.0146; specificity: 100%). This unexpected cellular localization was confirmed by cell fractionation. The beneficial effect of nuclear IL-23p19 was restricted to tumours with CD8+ high counts. Results were validated on Cohorts 2/3. This multicenter study underlines the possible CD8(+)--dependency and beneficial effect of nuclear IL-23p19 on overall patient survival.

Genetic identification of an oxyurid from a captive, black-handed spider monkey—implications for treatment and control

Parasites are of major clinical significance in captive primates in zoos, particularly those with direct life cycles. Oxyurid nematodes can be a persistent problem, as infection intensity and environmental contamination with infective eggs are usually high. Observations at the Basel Zoo in Switzerland have revealed that particularly black-handed spider monkeys (Ateles geoffroyi) exhibit continuous oxyurid nematode infection(s), despite regular deworming with anthelmintics. In the present study, using a molecular approach, we were able to identify the nematode (Trypanoxyuris atelis) causing this ongoing problem, and we are now evaluating a practical treatment and control regimen to tackle this parasite problem.

Treatment of echinococcosis: albendazole and mebendazole - what else?

The search for novel therapeutic options to cure alveolar echinococcosis (AE), due to the metacestode of Echinococcus multilocularis, is ongoing, and these developments could also have a profound impact on the treatment of cystic echinococcosis (CE), caused by the closely related Echinococcus granulosus s.l. Several options are being explored. A viable strategy for the identification of novel chemotherapeutically valuable compounds includes whole-organism drug screening, employing large-scale in vitro metacestode cultures and, upon identification of promising compounds, verification of drug efficacy in small laboratory animals. Clearly, the current focus is targeted towards broad-spectrum anti-parasitic or anti-cancer drugs and compound classes that are already marketed, or that are in development for other applications. The availability of comprehensive Echinococcus genome information and gene expression data, as well as significant progress on the molecular level, has now opened the door for a more targeted drug discovery approach, which allows exploitation of defined pathways and enzymes that are essential for the parasite. In addition, current in vitro and in vivo models that are used to assess drug efficacy should be optimized and complemented by methods that give more detailed information on the host-parasite interactions that occur during drug treatments. The key to success is to identify, target and exploit those parasite molecules that orchestrate activities essential to parasite survival.