847 research outputs found
Recommendations for HER2 testing in the UK
Determining the HER2 status of breast carcinomas is a prerequisite for the use of the monoclonal antibody trastuzumab (Herceptin(R)), which has recently been licensed for the treatment of metastatic disease. This necessitates a test based on archival material. The preferred analyses are immunohistochemistry with fluorescent in situ hybridisation (FISH) as a follow up test for ambiguous results. Guidelines have been developed for standardised, well controlled procedures for the provision of reliable results. A group of three reference laboratories has been established to provide advice, quality assurance, and materials, where needed
Genetic factors regulating lung vasculature and immune cell functions associate with resistance to pneumococcal infection
Streptococcus pneumoniae is an important human pathogen responsible for high mortality and morbidity worldwide. The susceptibility to pneumococcal infections is controlled by as yet unknown genetic factors. To elucidate these factors could help to develop new medical treatments and tools to identify those most at risk. In recent years genome wide association studies (GWAS) in mice and humans have proved successful in identification of causal genes involved in many complex diseases for example diabetes, systemic lupus or cholesterol metabolism. In this study a GWAS approach was used to map genetic loci associated with susceptibility to pneumococcal infection in 26 inbred mouse strains. As a result four candidate QTLs were identified on chromosomes 7, 13, 18 and 19. Interestingly, the QTL on chromosome 7 was located within S. pneumoniae resistance QTL (Spir1) identified previously in a linkage study of BALB/cOlaHsd and CBA/CaOlaHsd F2 intercrosses. We showed that only a limited number of genes encoded within the QTLs carried phenotype-associated polymorphisms (22 genes out of several hundred located within the QTLs). These candidate genes are known to regulate TGFb signalling, smooth muscle and immune cells functions. Interestingly, our pulmonary histopathology and gene expression data demonstrated, lung vasculature plays an important role in resistance to pneumococcal infection. Therefore we concluded that the cumulative effect of these candidate genes on vasculature and immune cells functions as contributory factors in the observed differences in susceptibility to pneumococcal infection. We also propose that TGFbmediated regulation of fibroblast differentiation plays an important role in development of invasive pneumococcal disease.This work was supported by the European Union-funded Pneumopath Project HEALTH-F3-2009-222983. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer-reviewedPublisher Versio
Is PPARγ a Prospective Player in HIV-1-Associated Bone Disease?
Currently infection with the human immunodeficiency virus-1 (HIV-1) is in most instances a chronic disease that can be controlled by effective antiretroviral therapy (ART). However, chronic use of ART has been associated with a number of toxicities; including significant reductions in bone mineral density (BMD) and disorders of the fat metabolism. The peroxisome proliferator-activated receptor gamma (PPARγ) transcription factor is vital for the development and maintenance of mature and developing adipocytes. Alterations in PPARγ expression have been implicated as a factor in the mechanism of HIV-1-associated lipodystrophy. Both reduced BMD and lipodystrophy have been well described as complications of HIV-1 infection and treatment, and a question remains as to their interdependence. Interestingly, both adipocytes and osteoblasts are derived from a common precursor cell type; the mesenchymal stem cell. The possibility that dysregulation of PPARγ (and the subsequent effect on both osteoblastogenesis and adipogenesis) is a contributory factor in the lipid- and bone-abnormalities observed in HIV-1 infection and treatment has also been investigated. This review deals with the hypothesis that dysregulation of PPARγ may underpin the bone abnormalities associated with HIV-1 infection, and treats the current knowledge and prospective developments, in our understanding of PPARγ involvement in HIV-1-associated bone disease
Neural Level Set Topology Optimization Using Unfitted Finite Elements
To facilitate widespread adoption of automated engineering design techniques,
existing methods must become more efficient and generalizable. In the field of
topology optimization, this requires the coupling of modern optimization
methods with solvers capable of handling arbitrary problems. In this work, a
topology optimization method for general multiphysics problems is presented. We
leverage a convolutional neural parameterization of a level set for a
description of the geometry and use this in an unfitted finite element method
that is differentiable with respect to the level set everywhere in the domain.
We construct the parameter to objective map in such a way that the gradient can
be computed entirely by automatic differentiation at roughly the cost of an
objective function evaluation. The method produces optimized topologies that
are similar in performance yet exhibit greater regularity than baseline
approaches on standard benchmarks whilst having the ability to solve a more
general class of problems, e.g., interface-coupled multiphysics.Comment: 16 pages + refs, 10 fig
Takotsubo Cardiomyopathy: A Case Series and Review of the Literature
Takotsubo cardiomyopathy (TCM) is an unusual form of acute cardiomyopathy showing left ventricular apical ballooning. It is often triggered by intense physical or emotional distress. We report here four cases of TCM and a review of the literature on the topic
Antiretroviral Therapy and Dyslipidaemia: Unlocking the Code
Mallon discusses a new study that describes associations between apoC-III polymorphisms and triglyceride concentrations in a large population of HIV-infected patients from a variety of ethnic backgrounds
Relationship between urinary calcium and calcium intake during calcitriol administration
Relationship between urinary calcium and calcium intake during calcitriol administration. The hypercalciuria that occurs when 1,25(OH)2D3 (calcitriol) is given to humans with normal renal function depends on dietary Ca absorption and may also relate, in part, to enhanced bone resorption. To evaluate the relationship between urinary and dietary Ca during treatment with calcitriol, 12 metabolic balance studies were performed in normal volunteers ingesting a diet containing 350 mg/day of Ca, to which Ca gluconate was added. After 10 days on either 350 mg/day or 1550 mg/day of Ca, calcitriol, 0.5 µg every 12hr, was given. Then diet Ca was changed in successive 5-day treatment periods from 350 to 650, 950 and 1550 mg/day (group A) or from 1550 to 950, 650 and 350 mg/day (group B). On the lowest diet Ca, urinary Ca was less than Ca intake during calcitriol treatment (group A, 220 ± 50 mg/day; group B, 247 ± 40). As diet Ca was changed during calcitriol treatment, urinary Ca correlated with diet Ca (r = 0.60) until diet Ca reached 950 mg/day. With calcitriol, serum iPTH fell by 18 to 25% (P < 0.01) and urinary hydroxyproline fell by 11 to 19% (P < 0.05 to 0.01). Baseline serum levels of 1,25(OH)2D were 47 ± 8 and 34 ± 5 pg/ml in group A and B, respectively, and the values increased to 51 ± 12 and 45 ±7.4 pg/ml during treatment with calcitriol. Serum Ca from fasted subjects was not affected by calcitriol, but the mean postabsorptive serum Ca (noon) was increased by 0.35 mg/dl. Although urine Ca/creatinine from fasted subjects increased with calcitriol treatment, the values varied directly with the 24-hr urine Ca and inversely with serum iPTH levels. Thus, dietary Ca is the major determinant of urinary Ca during treatment with calcitriol, and the latter may decrease dietary Ca requirements. There was no evidence for an increased bone resorption. The reduction of hydroxyproline excretion suggests that bone resorption was initially depressed, perhaps due to iPTH suppression. The data also suggest that urine Ca/creatinine after fasting for 12 hr is influenced by previous dietary Ca intake or intestinal Ca absorption, perhaps related to changing iPTH levels
The Explication Defence of Arguments from Reference
In a number of influential papers, Machery, Mallon, Nichols and Stich have presented a powerful critique of so-called arguments from reference, arguments that assume that a particular theory of reference is correct in order to establish a substantive conclusion. The critique is that, due to cross-cultural variation in semantic intuitions supposedly undermining the standard methodology for theorising about reference, the assumption that a theory of reference is correct is unjustified. I argue that the many extant responses to Machery et al.’s critique do little for the proponent of an argument from reference, as they do not show how to justify the problematic assumption. I then argue that it can in principle be justified by an appeal to Carnapian explication. I show how to apply the explication defence to arguments from reference given by Andreasen (for the biological reality of race) and by Churchland (against the existence of beliefs and desires)
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