Exploring the failing right ventricle in pulmonary hypertension by cardiac magnetic resonance: An in vivo study utilizing Macitentan.

Cardiac magnetic resonance (CMR) imaging is used to assess the right ventricle (RV) of pulmonary hypertensive (PH) patients and more recently to track changes in response to therapy. We wished to investigate if repeat CMRs could be used to assess ventricular changes in the Sugen 5416 hypoxic (Su/Hx) rat model of PH treated with the dual endothelin receptor antagonist Macitentan. Male Sprague Dawley Su/Hx rats were dosed for 3 weeks with either vehicle or Macitentan (30 mg/kg) daily, control rats received only vehicle. All rats underwent three CMR scans; before treatment, 2 weeks into treatment, and end of the study. A separate group of Su/Hx and control rats, treated as above, underwent terminal hemodynamic measurements. Using terminal and CMR measurements, Macitentan was found to lower RV systolic pressure pulmonary artery remodeling and increase RV ejection fraction but not change RV hypertrophy (RVH). Repeat CMRs determined that Su/Hx rats treated with Macitentan had significantly reversed RVH via reducing RV mass as well as reducing elevated left ventricular eccentricity index; reductions in RV mass were also observed in Su/Hx vehicle rats exposed to normoxic conditions. We have demonstrated that repeat CMRs can be used to assess the volume and structural changes in the ventricles of the Su/Hx rat model. Using repeat CMRs has allowed us to build a more complete picture of the response of the RV and the left ventricle to treatment. It is unknown if these effects are a consequence of direct action on the RV or secondary to improvements in the lung vasculature.

Treatment of multiple residual complex coronary to right ventricular fistulae with covered stents following previous coil embolization.

Congenital coronary artery fistulae may be isolated or may be associated with complex congenital cardiac abnormalities. In patients with complex congenital heart disease, multiple fistulous or sinusoidal communications with a cardiac chamber can occur. The treatment strategy includes surgery, coil embolization and covered stent deployment. The present article describes a case involving a 20-year-old patient with complex congenital heart lesions and multiple sinusoidal coronary to right ventricle fistulous communications, which remained patent despite coil embolization in childhood. Further coil or device embolization was deemed unlikely to be successful due to the presence of multiple communications; therefore, covered stents were deployed across the previously coiled segment of the coronary artery. The patient had an excellent clinical outcome on follow-up nine months later, with significant improvement of symptoms.

Bile UPLC-MS fingerprinting and bile acid fluxes during human liver transplantation.

Bile flow restoration is a crucial step in the recovery process post transplantation of the liver. Here, metabolic trajectories based on changes in bile secretion - a known marker of functionality - have been utilised as an approach for discovering bile fluxes during transplantation. A total of ten liver transplants were monitored and from these 68 bile samples from both donors and recipients were collected and analysed using ultra-performance LC-MS in combination with multivariate statistical analysis. Based on the principal component scores constructed from the total bile fingerprint, differentiation of the bile acid concentrations before and after transplantation was detected. A trend was also observed, by constructing metabolic trajectories, whereby the post-transplant profiles approached the position of pre-transplant profiles within 30-60 min of the restoration of bile secretion function. The ten major conjugated bile acid salts were measured and a significant increase in concentrations of taurocholic acid and taurochenodeoxycholic acid were seen after transplantation. In addition, the ratios of secondary bile acids detected in gall bladder and hepatic bile were measured before and after transplantation. This study suggests that bile acid ratios in the donor liver at the pre-transplant and post-transplant stage may be important and that profiling of secreted bile after transplantation may aid clinical assessment and progress post-transplantation.

Identification of metabolites in human hepatic bile using 800 MHz 1H NMR spectroscopy, HPLC-NMR/MS and UPLC-MS.

The first application of high field NMR spectroscopy (800 MHz for (1)H observation) to human hepatic bile (as opposed to gall bladder bile) is reported. The bile sample used for detailed investigation was from a donor liver with mild fat infiltration, collected during organ retrieval prior to transplantation. In addition, to focus on the detection of bile acids in particular, a bile extract was analysed by 800 MHz (1)H NMR spectroscopy, HPLC-NMR/MS and UPLC-MS. In the whole bile sample, 40 compounds have been assigned with the aid of two-dimensional (1)H-(1)H TOCSY and (1)H-(13)C HSQC spectra. These include phosphatidylcholine, 14 amino acids, 10 organic acids, 4 carbohydrates and polyols (glucose, glucuronate, glycerol and myo-inositol), choline, phosphocholine, betaine, trimethylamine-N-oxide and other small molecules. An initial NMR-based assessment of the concentration range of some key metabolites has been made. Some observed chemical shifts differ from expected database values, probably due to a difference in bulk diamagnetic susceptibility. The NMR spectra of the whole extract gave identification of the major bile acids (cholic, deoxycholic and chenodeoxycholic), but the glycine and taurine conjugates of a given bile acid could not be distinguished. However, this was achieved by HPLC-NMR/MS, which enabled the separation and identification of ten conjugated bile acids with relative abundances varying from approximately 0.1% (taurolithocholic acid) to 34.0% (glycocholic acid), of which, only the five most abundant acids could be detected by NMR, including the isomers glycodeoxycholic acid and glycochenodeoxycholic acid, which are difficult to distinguish by conventional LC-MS analysis. In a separate experiment, the use of UPLC-MS allowed the detection and identification of 13 bile acids. This work has shown the complementary potential of NMR spectroscopy, MS and hyphenated NMR/MS for elucidating the complex metabolic profile of human hepatic bile. This will be useful baseline information in ongoing studies of liver excretory function and organ transplantation.

First example of hepatocyte transplantation to alleviate ornithine transcarbamylase deficiency, monitored by NMR-based metabonomics.

We demonstrate the effective use of NMR spectroscopic profiles of urine and plasma from the first successful use of hepatocyte transplantation as a bridge to auxiliary partial orthotopic liver transplantation in a child antenatally diagnosed with severe ornithine transcarbamylase deficiency. In this single-patient study, NMR profiles indicated that the disrupted urea cycle could be normalized by hepatocyte cell infusion and this was confirmed using orthogonal partial least-squares-based chemometrics. However, despite dietary manipulations and adminstration of ammonia scavengers, the desired reduction in plasma ammonia was not consistently achieved between sessions of hepatocyte transplantation due to episodes of sepsis. A subsequent liver transplant corrected the metabolic abnormalities. The use of metabolic profiling has been shown to be a promising method for evaluating the efficacy of cell infusions and has demonstrated the capability for the early detection of response to therapy in real time, an approach that may be of use in wider clinical settings.

Effective interprofessional teams: "contact is not enough" to build a team.

INTRODUCTION: Teamwork and interprofessional practice and learning are becoming integral to health care. It is anticipated that these approaches can maximize professional resources and optimize patient care. Current research, however, suggests that primary health care teams may lack the capacity to function at a level that enhances the individual contributions of their members and team effectiveness. This study explores perceptions of effective primary health care teams to determine the related learning needs of primary health care professionals. METHODS: Primary health care team members with a particular interest in teamwork shared perspectives of effective teamwork and educational needs in interprofessional focus groups. Transcripts from nine focus groups with a total of 61 participants were analyzed using content analysis and grounded hermeneutic approaches to identify themes. RESULTS: Five themes of primary care team effectiveness emerged: (1) understanding and respecting team members' roles, (2) recognizing that teams require work, (3) understanding primary health care, (4) working together: practical "know-how" for sharing patient care, and (5) communication. Communication was identified as the essential factor in effective primary health care teams. DISCUSSION: Several characteristics of effective primary health care teams and the related knowledge and skills that professionals require as effective team members are identified. Effective teamwork requires specific cognitive, technical, and affective competence.

Fingerprinting of human bile during liver transplantation by capillary electrophoresis.

Increasing rates of success in liver transplantation have increased the number of cases considered. However, liver post-transplant graft dysfunction of liver transplants (TXs) is not fully understood and by applying holistic approaches we can investigate metabolic change deriving from confounding factors such as liver fat content, ischaemia time, donor age, recipient's health, etc. Twenty-six hepatic bile samples taken from liver donors and recipients were retrieved from a total of six TXs, from these one recipient underwent post-graft dysfunction. CE was employed to fingerprint bile collected at 10 min increments in the donors and in the recipients. The electropherograms of these samples were aligned and normalised using correlation optimised warping algorithms and modelled with multivariate techniques. The resulting metabolic signatures were compared; in general donors and recipients showed distinct fingerprints and clustered separately. When a partial least square discriminant analysis (PLS-DA) model was constructed between donor and recipient's samples, a recipient of a 32 year old liver with normal steatosis, and shortest cold ischaemia time showed as the observation nearest to its donor observation, denoting minimal metabolic change. This study proposes CE fingerprinting of human bile as a promising technique to help unravel the complex metabolic pathways involved during transplantation.

A top-down systems biology view of microbiome-mammalian metabolic interactions in a mouse model.

Symbiotic gut microorganisms (microbiome) interact closely with the mammalian host's metabolism and are important determinants of human health. Here, we decipher the complex metabolic effects of microbial manipulation, by comparing germfree mice colonized by a human baby flora (HBF) or a normal flora to conventional mice. We perform parallel microbiological profiling, metabolic profiling by (1)H nuclear magnetic resonance of liver, plasma, urine and ileal flushes, and targeted profiling of bile acids by ultra performance liquid chromatography-mass spectrometry and short-chain fatty acids in cecum by GC-FID. Top-down multivariate analysis of metabolic profiles reveals a significant association of specific metabotypes with the resident microbiome. We derive a transgenomic graph model showing that HBF flora has a remarkably simple microbiome/metabolome correlation network, impacting directly on the host's ability to metabolize lipids: HBF mice present higher ileal concentrations of tauro-conjugated bile acids, reduced plasma levels of lipoproteins but higher hepatic triglyceride content associated with depletion of glutathione. These data indicate that the microbiome modulates absorption, storage and the energy harvest from the diet at the systems level.

Metabolic assessment of human liver transplants from biopsy samples at the donor and recipient stages using high-resolution magic angle spinning 1H NMR spectroscopy.

This work presents the first application of high-resolution magic angle spinning (HR-MAS) 1H NMR spectroscopy to human liver biopsy samples, allowing a determination of their metabolic profiles before removal from donors, during cold perfusion, and after implantation into recipients. The assignment of peaks observed in the 1H HR-MAS NMR spectra was aided by the use of two-dimensional J-resolved, TOCSY and 1H-13C HMQC spectra. The spectra were dominated by resonances from triglycerides, phospholipids, and glycogen and from a variety of small molecules including glycerophosphocholine (GPC), glucose, lactate, creatine, acetate, amino acids, and nucleoside-related compounds such as uridine and adenosine. In agreement with histological data obtained on the same biopsies, two of the six livers were found to contain high amounts of triglycerides by NMR spectroscopy, which also indicated that these tissues contained a higher degree of unsaturated lipids and a lower proportion of phospholipids and low molecular weight compounds. Additionally, proton T2 relaxation times indicated two populations of lipids, a higher mobility triglyceride fraction and a lower mobility phospholipid fraction, the proportions of which changed according to the degree of fat content. GPC was found to decrease from the pretransplant to the posttransplant biopsy of all livers except for one with a histologically confirmed high lipid content, and this might represent a biomarker of liver function posttransplantation. NMR signals produced by the liver preservation solution were clearly detected in the cold perfusion stage biopsies of all livers but remained in the posttransplant spectra of only the two livers with a high lipid content and were prominent mainly in the graft that later developed primary graft dysfunction. This study has shown biochemical differences between livers used for transplants that can be related to the degree and type of lipid composition. This technology might therefore provide a novel screening approach for donor organ quality and a means to assess function in the recipient after transplantation.

Bile acids analysis: a tool to assess graft function in human liver transplantation.

The expanding use of "sub-optimal" grafts due to donor organ shortage increases the importance of accurate graft assessment before liver transplantation. Bile secretion is an early sign of recovering hepatic function post-transplant. The role of bile acid analysis in assessing graft function before and immediately after liver transplantation has been investigated. Two hundred and sixteen samples of hepatic bile were collected from 35 donors and 13 recipients. Clinical data, bile flow, total bile acid concentration, apparent choleretic activity and bile acid composition were assessed. Sub-optimal donor livers showed a low apparent choleretic activity and a different bile acid composition when compared to normal grafts. In recipients, the pattern of recovery of bile secretion immediately after reperfusion was a useful predictor of graft function. This study characterises bile acid secretion of liver grafts and remarks the potential value of bile acid analysis to assess donor liver quality and early post-transplant graft function.

Modulation of matrix gelatinases and metalloproteinase-activating process in acute kidney rejection.

Changes in matrix metalloproteinase (MMP) activities would contribute to the accumulation of extracellular matrix during acute kidney allograft rejection. MMP-2 and MMP-9 and other gelatinolytic activities were examined in the rejected graft and the urine of a rat model of acute kidney rejection (orthotopic allotransplantation from a Buffalo donor to a Wistar-Furth recipient) by either zymography or fluorescence assay. MMP-2, membrane type 1 (MT1)-MMP, and tissue inhibitor of metalloproteinase (TIMP)-2 were also examined by immunodetection. The proMMP-2 activity and protein level increased in the graft during rejection when compared with normal Buffalo kidney, whereas activated MMP-2 decreased. TIMP-2 protein levels were markedly decreased and MT1-MMP proteolytic fragments (44-40 kDa) were undetectable. This suggests an altered MT1-MMP-dependent processing of proMMP-2 into active MMP-2 due to a diminished TIMP-2 level in acute kidney rejection. In the urine the overall gelatinolytic activity decreased considerably, although activity associated with an as yet unidentified 78-kDa protein appeared 6 days after transplantation.