Targeting Complement Pathways During Cold Ischemia and Reperfusion Prevents Delayed Graft Function

The complement system plays a critical role in ischemia-reperfusion injury (IRI)-mediated delayed graft function (DGF). To better understand the roles of complement activation pathways in IRI in kidney transplantation, donor kidneys were treated ex vivo with terminal complement pathway (TP) inhibitor, anti-rat C5 mAb 18A10, or complement alternative pathway (AP) inhibitor TT30 for 28 h at 4°C pretransplantation in a syngeneic kidney transplantation rat model. All 18A10- and 67% of TT30-pretreated grafts, but only 16.7% of isotype control-pretreated grafts, survived beyond day 21 (p < 0.01). Inhibitor treatment in the final 45 min of 28-h cold ischemia (CI) similarly improved graft survival. Systemic posttransplant treatment with 18A10 resulted in 60% increased graft survival beyond day 21 (p < 0.01), while no TT30-treated rat survived > 6 days. Our results demonstrate that AP plays a prominent role during CI and that blocking either the AP or, more effectively the TP prevents ischemic injury and subsequent DGF. Multiple complement pathways may be activated and contribute to reperfusion injury; blocking the TP, but not the AP, posttransplant is effective in preventing reperfusion injury and increasing graft survival. These results demonstrate the feasibility of using complement inhibitors for prevention of DGF in humans.

BOLD fMRI in awake prairie voles: A platform for translational social and affective neuroscience

The advancement of neuroscience depends on continued improvement in methods and models. Here, we present novel techniques for the use of awake functional magnetic resonance imaging (fMRI) in the prairie vole (Microtus ochrogaster) - an important step forward in minimally-invasive measurement of neural activity in a non-traditional animal model. Imaging neural responses in prairie voles, a species studied for its propensity to form strong and selective social bonds, is expected to greatly advance our mechanistic understanding of complex social and affective processes. The use of ultra-high-field fMRI allows for recording changes in region-specific activity throughout the entire brain simultaneously and with high temporal and spatial resolutions. By imaging neural responses in awake animals, with minimal invasiveness, we are able to avoid the confound of anesthesia, broaden the scope of possible stimuli, and potentially make use of repeated scans from the same animals. These methods are made possible by the development of an annotated and segmented 3D vole brain atlas and software for image analysis. The use of these methods in the prairie vole provides an opportunity to broaden neuroscientific investigation of behavior via a comparative approach, which highlights the ethological relevance of pro-social behaviors shared between voles and humans, such as communal breeding, selective social bonds, social buffering of stress, and caregiving behaviors. Results using these methods show that fMRI in the prairie vole is capable of yielding robust blood oxygen level dependent (BOLD) signal changes in response to hypercapnic challenge (inhaled 5% CO2), region-specific physical challenge (unilateral whisker stimulation), and presentation of a set of novel odors. Complementary analyses of repeated restraint sessions in the imaging hardware suggest that voles do not require acclimation to this procedure. Taken together, awake vole fMRI represents a new arena of neurobiological study outside the realm of traditional rodent models.

Suppression of TGFβ and Angiogenesis by Type VII Collagen in Cutaneous SCC

BACKGROUND

Individuals with severe generalized recessive dystrophic epidermolysis bullosa (RDEB), an inherited blistering disorder caused by mutations in the COL7A1 gene, develop unexplained aggressive squamous cell carcinomas (SCC). Here we report that loss of type VII collagen (Col7) in SCC results in increased TGFβ signaling and angiogenesis in vitro and in vivo.

METHODS

Stable knockdown (KD) of Col7 was established using shRNA, and cells were used in a mouse xenograft model. Angiogenesis was assessed by immunohistochemistry, endothelial tube-forming assays, and proteome arrays. Mouse and zebrafish models were used to examine the effect of recombinant Col7 on angiogenesis. Findings were confirmed in anonymized, archival human tissue: RDEB SCC tumors, non-EB SCC tumors, RDEB skin, normal skin; and two human RDEB SCC cell lines. The TGFβ pathway was examined using immunoblotting, immunohistochemistry, biochemical inhibition, and siRNA. All statistical tests were two-sided.

RESULTS

Increased numbers of cross-cut blood vessels were observed in Col7 KD compared with control xenografts (n = 4 to 7 per group) and in RDEB tumors (n = 21) compared with sporadic SCC (n = 24, P < .001). Recombinant human Col7 reversed the increased SCC angiogenesis in Col7 KD xenografts in vivo (n = 7 per group, P = .04). Blocking the interaction between α2β1 integrin and Col7 increased TGFB1 mRNA expression 1.8-fold and p-Smad2 levels two-fold. Increased TGFβ signaling and VEGF expression were observed in Col7 KD xenografts (n = 4) compared with control (n = 4) and RDEB tumors (TGFβ markers, n = 6; VEGF, n = 17) compared with sporadic SCC (TGFβ markers, n = 6; VEGF, n = 21). Inhibition of TGFβ receptor signaling using siRNA resulted in decreased endothelial cell tube formation (n = 9 per group, mean tubes per well siC = 63.6, SD = 17.1; mean tubes per well siTβRII = 29.7, SD = 6.1, P = .02).

CONCLUSIONS

Type VII collagen suppresses TGFβ signaling and angiogenesis in cutaneous SCC. Patients with RDEB SCC may benefit from anti-angiogenic therapy.

Assessing the performance of the Oxford Nanopore Technologies MinION

The Oxford Nanopore Technologies (ONT) MinION is a new sequencing technology that potentially offers read lengths of tens of kilobases (kb) limited only by the length of DNA molecules presented to it. The device has a low capital cost, is by far the most portable DNA sequencer available, and can produce data in real-time. It has numerous prospective applications including improving genome sequence assemblies and resolution of repeat-rich regions. Before such a technology is widely adopted, it is important to assess its performance and limitations in respect of throughput and accuracy. In this study we assessed the performance of the MinION by re-sequencing three bacterial genomes, with very different nucleotide compositions ranging from 28.6% to 70.7%; the high G + C strain was underrepresented in the sequencing reads. We estimate the error rate of the MinION (after base calling) to be 38.2%. Mean and median read lengths were 2 kb and 1 kb respectively, while the longest single read was 98 kb. The whole length of a 5 kb rRNA operon was covered by a single read. As the first nanopore-based single molecule sequencer available to researchers, the MinION is an exciting prospect; however, the current error rate limits its ability to compete with existing sequencing technologies, though we do show that MinION sequence reads can enhance contiguity of de novo assembly when used in conjunction with Illumina MiSeq data.

A prognostic nomogram to predict overall survival in women with recurrent ovarian cancer treated with bevacizumab and chemotherapy

OBJECTIVE

To develop a nomogram to predict overall survival (OS) in women with recurrent ovarian cancer treated with bevacizumab and chemotherapy.

METHODS

A multicenter retrospective study was conducted. Potential prognostic variables included age; stage; grade; histology; performance status; residual disease; presence of ascites and/or pleural effusions; number of chemotherapy regimens, treatment-free interval (TFI) prior to bevacizumab administration, and platinum sensitivity. Multivariate analysis was performed using Cox proportional hazards regression. The predictive model was developed into a nomogram to predict five-year OS.

RESULTS

312 women with recurrent ovarian cancer treated with bevacizumab and chemotherapy were identified; median age was 59 (range: 19-85); 86% women had advanced stage (III-IV) disease. The majority had serous histology (74%), high grade cancers (93.5%), and optimal cytoreductions (69.5%). Fifty-one percent of women received greater than two prior chemotherapeutic regimens. TFI (AHR=0.98, 95% CI 0.97-1.00, p=0.022) was the only statistically significant predictor in a multivariate progression-free survival (PFS) analysis. In a multivariate OS analysis, prior number of chemotherapy regimens, TFI, platinum sensitivity, and presence of ascites were significant. A nomogram to predict five-year OS was constructed and internally validated (bootstrap-corrected concordance index=0.737).

CONCLUSION

Our multivariate model identified prior number of chemotherapy regimens, TFI, platinum sensitivity, and the presence of ascites as prognostic variables for OS in women with recurrent ovarian cancer treated with bevacizumab combined with chemotherapy. Our nomogram to predict five-year OS may be used to identify women who may benefit from bevacizumab and chemotherapy, but further validation is needed.

Empirical examination of the interpersonal maintenance model of anorexia nervosa

OBJECTIVE

A cognitive interpersonal maintenance model of anorexia nervosa (AN) was first proposed in 2006 and updated in 2013 (Schmidt and Treasure, J Br J Clin Psychol, 45, 343-366, 2006; Treasure and Schmidt, J Eat Disorders, in press.). The aim of this study was to test the interpersonal component of this model in people with AN requiring intensive hospital treatment (inpatient/day patient).

METHOD

On admission to hospital women with AN or eating disorder not otherwise specified (AN subtype; n = 152; P) and their primary carers (n = 152; C) completed questionnaires on eating symptoms (P), depression and anxiety (P, C), accommodation and enabling (C), and psychological control (C). Structural equation modeling was used to examine relationships among these components.

RESULTS

Carers' expressed emotion and level of psychological control were significantly related to carers' distress, which in turn, was related to patients' distress. This pathway significantly predicted eating symptoms in patients.

DISCUSSION

The cognitive interpersonal maintenance model of eating disorders (EDs) was confirmed in part and suggests that interventions targeting interpersonal maintaining factors such as carer distress might impact on patient outcomes.

Mortality among veterans with type 2 diabetes initiating metformin, sulfonylurea or rosiglitazone monotherapy

AIMS/HYPOTHESES

Despite oral hypoglycaemic medications being the most commonly used pharmacological treatments for type 2 diabetes, research is limited on their comparative safety, particularly their effects on overall mortality. We compared mortality risk with monotherapy initiation of four oral hypoglycaemic medications in a nationwide cohort of US veterans with type 2 diabetes.

METHODS

We identified new users of oral hypoglycaemic medication monotherapy between 2004 and 2009 who received care for at least 1 year from the Veterans Health Administration.Patients were followed until initial monotherapy discontinuation,addition of another diabetes pharmacotherapy, death or end of follow-up. Mortality HRs were estimated using Cox regression adjusted for potential confounding factors.

RESULTS

Among new users of metformin, sulfonylureas and rosiglitazone (185,360 men, 7,812 women), 4,256 (2.2%) died during follow-up. Average duration of medication use ranged from 1.4 to 1.7 years. Significantly higher mortality risk was seen for glibenclamide (known as glyburide in the USA and Canada) (HR 1.38, 95% CI 1.27, 1.50) or glipizide (HR 1.55,95% CI 1.43, 1.67) compared with metformin monotherapy,and for glipizide compared with rosiglitazone (HR 1.27, 95%CI 1.01, 1.59) or glibenclamide monotherapy (HR 1.12, 95%CI 1.02, 1.23). A significant sex–rosiglitazone interaction was seen (p=0.034) compared with metformin monotherapy, with women having a higher HR (HR 4.36, 95% CI 1.34, 14.20)than men (HR 1.19, 95% CI 0.95, 1.49).

CONCLUSIONS/INTERPRETATIONS

Significantly higher mortality was associated with glibenclamide, glipizide and rosiglitazone use compared with metformin, and with glipizide use compared with rosiglitazone or glibenclamide. The potential for residual confounding by indication should be considered in interpreting these results.