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A multi-modal data resource for investigating topographic heterogeneity in patient-derived xenograft tumors.
Patient-derived xenografts (PDXs) are an essential pre-clinical resource for investigating tumor biology. However, cellular heterogeneity within and across PDX tumors can strongly impact the interpretation of PDX studies. Here, we generated a multi-modal, large-scale dataset to investigate PDX heterogeneity in metastatic colorectal cancer (CRC) across tumor models, spatial scales and genomic, transcriptomic, proteomic and imaging assay modalities. To showcase this dataset, we present analysis to assess sources of PDX variation, including anatomical orientation within the implanted tumor, mouse contribution, and differences between replicate PDX tumors. A unique aspect of our dataset is deep characterization of intra-tumor heterogeneity via immunofluorescence imaging, which enables investigation of variation across multiple spatial scales, from subcellular to whole tumor levels. Our study provides a benchmark data resource to investigate PDX models of metastatic CRC and serves as a template for future, quantitative investigations of spatial heterogeneity within and across PDX tumor models
The Impact of Parameter Identification Methods on Drug Therapy Control in an Intensive Care Unit
This paper investigates the impact of fast parameter identification methods, which do not require any forward simulations, on model-based glucose control, using retrospective data in the Christchurch Hospital Intensive Care Unit. The integral-based identification method has been previously clinically validated and extensively applied in a number of biomedical applications; and is a crucial element in the presented model-based therapeutics approach. Common non-linear regression and gradient descent approaches are too computationally intense and not suitable for the glucose control applications presented. The main focus in this paper is on better characterizing and understanding the importance of the integral in the formulation and the effect it has on model-based drug therapy control. As a comparison, a potentially more natural derivative formulation which has the same computation speed advantages is investigated, and is shown to go unstable with respect to modelling error which is always present clinically. The integral method remains robust
Lipid metabolism in patients infected with Nef-deficient HIV-1 strain
Background: HIV protein Nef plays a key role in impairing cholesterol metabolism in both HIV infected and bystander cells. The existence of a small cohort of patients infected with Nef-deficient strain of HIV presented a unique opportunity to test the effect of Nef on lipid metabolism in a clinical setting. Methods: Here we report the results of a study comparing six patients infected with Nef-deficient strain of HIV (Delta NefHIV) with six treatment-naive patients infected with wild-type HIV (WT HIV). Lipoprotein profile, size and functionality of high density lipoprotein (HDL) particles as well as lipidomic and microRNA profiles of patient plasma were analyzed. Results: We found that patients infected with Delta NefHIV had lower proportion of subjects with plasma HDL-C levels < 1 mmol/l compared to patients infected with WT HIV. Furthermore, compared to a reference group of HIV-negative subjects, there was higher abundance of smaller under-lipidated HDL particles in plasma of patients infected with WT HIV, but not in those infected with Delta NefHIV. Lipidomic analysis of plasma revealed differences in abundance of phosphatidylserine and sphingolipids between patients infected with Delta NefHIV and WT HIV. MicroRNA profiling revealed that plasma abundance of 24 miRNAs, many of those involved in regulation of lipid metabolism, was differentially regulated by WT HIV and Delta NefHIV. Conclusion: Our findings are consistent with HIV protein Nef playing a significant role in pathogenesis of lipid-related metabolic complications of HIV disease
Lipid metabolism in patients infected with Nef-deficient HIV-1 strain.
BACKGROUND: HIV protein Nef plays a key role in impairing cholesterol metabolism in both HIV infected and bystander cells. The existence of a small cohort of patients infected with Nef-deficient strain of HIV presented a unique opportunity to test the effect of Nef on lipid metabolism in a clinical setting.
METHODS: Here we report the results of a study comparing six patients infected with Nef-deficient strain of HIV (ΔNefHIV) with six treatment-naïve patients infected with wild-type HIV (WT HIV). Lipoprotein profile, size and functionality of high density lipoprotein (HDL) particles as well as lipidomic and microRNA profiles of patient plasma were analyzed.
RESULTS: We found that patients infected with ΔNefHIV had lower proportion of subjects with plasma HDL-C levels/l compared to patients infected with WT HIV. Furthermore, compared to a reference group of HIV-negative subjects, there was higher abundance of smaller under-lipidated HDL particles in plasma of patients infected with WT HIV, but not in those infected with ΔNefHIV. Lipidomic analysis of plasma revealed differences in abundance of phosphatidylserine and sphingolipids between patients infected with ΔNefHIV and WT HIV. MicroRNA profiling revealed that plasma abundance of 24 miRNAs, many of those involved in regulation of lipid metabolism, was differentially regulated by WT HIV and ΔNefHIV.
CONCLUSION: Our findings are consistent with HIV protein Nef playing a significant role in pathogenesis of lipid-related metabolic complications of HIV disease
Wave energy absorption by a submerged air bag connected to a rigid float
A new wave energy device features a submerged ballasted air bag connected at
the top to a rigid float. Under wave action, the bag expands and contracts,
creating a reciprocating air flow through a turbine between the bag and another
volume housed within the float. Laboratory measurements are generally in good
agreement with numerical predictions. Both show that the trajectory of possible
combinations of pressure and elevation at which the device is in static
equilibrium takes the shape of an S. This means that statically the device can
have three different draughts, and correspondingly three different bag shapes,
for the same pressure. The behaviour in waves depends on where the mean
pressure-elevation condition is on the static trajectory. The captured power is
highest for a mean condition on the middle section.Comment: Revised version submitted to Proc R Soc
Workforce participation among international medical graduates in the National Health Service of England: a retrospective longitudinal study
<p>Abstract</p> <p>Background</p> <p>Balancing medical workforce supply with demand requires good information about factors affecting retention. Overseas qualified doctors comprise 30% of the National Health Service (NHS) workforce in England yet little is known about the impact of country of qualification on length of stay. We aimed to address this need.</p> <p>Methods</p> <p>Using NHS annual census data, we calculated the duration of 'episodes of work' for doctors entering the workforce between 1992 and 2003. Survival analysis was used to examine variations in retention by country of qualification. The extent to which differences in retention could be explained by differences in doctors' age, sex and medical specialty was examined by logistic regression.</p> <p>Results</p> <p>Countries supplying doctors to the NHS could be divided into those with better or worse long-term retention than domestically trained doctors. Countries in the former category were generally located in the Middle East, non-European Economic Area Europe, Northern Africa and Asia, and tended to be poorer with fewer doctors per head of population, but stronger economic growth. A doctor's age and medical specialty, but not sex, influenced patterns of retention.</p> <p>Conclusion</p> <p>Adjusting workforce participation by country of qualification can improve estimates of the number of medical school places needed to balance supply with demand. Developing countries undergoing strong economic growth are likely to be the most important suppliers of long stay medical migrants.</p
Autologous tooth graft after endodontical treated used for socket preservation: A multicenter clinical study.
The aim of the study was to evaluate the tooth extracted use as autologous tooth graft after endodontic root canal therapies used for socket preservation. To this purpose, the Tooth Transformer shredding and decontamination machine has been used. The graft obtained in this way, was inserted at the time of the extraction or at a second surgery altogether with the chosen regenerative therapy. This clinical trial enrolled patients with post-estractive defects requiring the restoration bone dimension and shape in the maxillary and mandibular zone. In addition, 98 patients with 119 extraction sockets were enrolled across 10 standardized centers. An innovative preparation method, using the dedicated automated device Tooth Transformer, able to transform autologous teeth in suitable grafting material, has been used. The extracted tooth was cleaned and treated using a Tooth Transformer and made a socket preservation. Thirteen Biopsies were realized to analyze the histologic outcomes at the average time of four months to demonstrate that the autologous tooth graft made from root after endodontic therapy should be used in human bone regeneration as graft for dental implant placement
Nebuliser therapy in the intensive care unit
The relationship between identity, lived experience, sexual practices and the language through which these are conveyed has been widely debated in sexuality literature. For example, ‘coming out’ has famously been conceptualised as a ‘speech act’ (Sedgwick 1990) and as a collective narrative (Plummer 1995), while a growing concern for individuals’ diverse identifications in relations to their sexual and gender practices has produced interesting research focusing on linguistic practices among LGBT-identified individuals (Leap 1995; Kulick 2000; Cameron and Kulick 2006; Farqhar 2000). While an explicit focus on language remains marginal to literature on sexualities (Kulick 2000), issue of language use and translation are seldom explicitly addressed in the growing literature on intersectionality. Yet intersectional perspectives ‘reject the separability of analytical and identity categories’ (McCall 2005:1771), and therefore have an implicit stake in the ‘vernacular’ language of the researched, in the ‘scientific’ language of the researcher and in the relationship of continuity between the two. Drawing on literature within gay and lesbian/queer studies and cross-cultural studies, this chapter revisits debates on sexuality, language and intersectionality. I argue for the importance of giving careful consideration to the language we choose to use as researchers to collectively define the people whose experiences we try to capture. I also propose that language itself can be investigated as a productive way to foreground how individual and collective identifications are discursively constructed, and to unpack the diversity of lived experience. I address intersectional complexity as a methodological issue, where methodology is understood not only as the methods and practicalities of doing research, but more broadly as ‘a coherent set of ideas about the philosophy, methods and data that underlie the research process and the production of knowledge’ (McCall 2005:1774). My points are illustrated with examples drawn from my ethnographic study on ‘lesbian’ identity in urban Russia, interspersed with insights from existing literature. In particular, I aim to show that an explicit focus on language can be a productive way to explore the intersections between the global, the national and the local in cross-cultural research on sexuality, while also addressing issues of positionality and accountability to the communities researched
A phase 1 study evaluating rovalpituzumab tesirine in frontline treatment of patients with extensive-stage SCLC
INTRODUCTION: Rovalpituzumab tesirine (Rova-T) is an antibody-drug conjugate targeting DLL3, a Notch pathway ligand highly expressed on SCLC cells. Rova-T was evaluated alone or in combination with platinum-based chemotherapy (cisplatin or carboplatin combined with etoposide [CE]) in frontline treatment of extensive-stage SCLC.
METHODS: One cycle of CE pre-enrollment was permitted (later mandated). The following four cohorts were enrolled: Rova-T monotherapy (0.3 mg/kg, every 6 [q6] wk × 2; cohort 1; n = 4); Rova-T induction (0.3 mg/kg, q6 wk × 2) followed by CE every 21 days (q21) × 4 (cohort 2; n = 5); Rova-T (0.1 or 0.2 mg/kg, q6 wk × 2) overlapping with CE q21 × 4 (cohort 3; n = 14); and Rova-T maintenance (0.3 mg/kg, q6 wk × 2) after CE q21 × 4 (cohort 4; n = 3).
RESULTS: A total of 26 patients were dosed (cohort 3: 14; cohorts 1, 2, and 4 combined: 12). Median age was 66 years, and 73% had Eastern Cooperative Oncology Group performance status of 1. In cohort 3, seven patients (50%) had confirmed objective responses, with a median progression-free survival of 5.2 months and median overall survival of 10.3 months. Compared with cohorts 1, 2, and 4 combined, cohort 3 had lower frequency of some Rova-T-related adverse events of special interest, such as pleural effusion (0 versus 33%), pericardial effusion (0 versus 17%), ascites (0 versus 8%), peripheral edema (36% versus 42%), generalized edema (0 versus 8%), pneumonia (7% versus 25%), and hypoalbuminemia (0 versus 17%).
CONCLUSIONS: Lower Rova-T doses may be associated with lower incidence of some Rova-T-related adverse events of special interest. Rova-T 0.2 mg/kg plus CE (cohort 3) was tolerable; however, there was no clear efficacy benefit of adding Rova-T to CE
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