1,065 research outputs found
Minimally invasive double lung transplantation technique (Anteroaxillary approach)
Lung transplantation has been performed through several approaches in the past. Sternothoracotomy is the most widely used approach for double lung transplantation. Although bilateral anterolateral thoracotomy for double lung transplantation has been described in the past, this approach has not widely adopted worldwide. The 'anteroaxillary approach' utilizes a limited incision compared to others, preserves sternal anatomy as well as thoracic arteries, and provides an excellent exposure to hilum. We would like to present our standard approach at University of Pittsburgh through anteroaxillary incision
Automated discrimination of psychotropic drugs in mice via computer vision-based analysis
Cataloged from PDF version of article.We developed an inexpensive computer vision-based method utilizing an algorithm which differentiates
drug-induced behavioral alterations. The mice were observed in an open-field arena and their activity
was recorded for 100 min. For each animal the first 50 min of observation were regarded as the drug-free
period. Each animal was exposed to only one drug and they were injected (i.p.) with either amphetamine
or cocaine as the stimulant drugs or morphine or diazepam as the inhibitory agents. The software divided
the arena into virtual grids and calculated the number of visits (sojourn counts) to the grids and instantaneous
speeds within these grids by analyzing video data. These spatial distributions of sojourn counts and
instantaneous speeds were used to construct feature vectors which were fed to the classifier algorithms
for the final step of matching the animals and the drugs. The software decided which of the animals were
drug-treated at a rate of 96%. The algorithm achieved 92% accuracy in sorting the data according to the
increased or decreased activity and then determined which drug was delivered. The method differentiated
the type of psychostimulant or inhibitory drugs with a success ratio of 70% and 80%, respectively.
This method provides a new way to automatically evaluate and classify drug-induced behaviors in mice.
Crown Copyright © 2009 Published by Elsevier B.V. All rights reserved
Rare malformation of glans penis: Arteriovenous malformation
Pediatric glans penis malformations, especially arteriovenous malformations (AVM), are very rare. Herein, we report two rare cases. A 14‑year‑old boy attended our outpatient clinic with chief complaints of purple swelling and rapidly growing lesion on the glans penis. The lesion was excised surgically after physical and radiological evaluations. Pathology reported AVM and the patient is being followed up. The second case is a 2‑year‑old boy who was admitted with a big lesion involving glans penis and genital area that has been present since birth. In physical and radiological evaluations, lesion on the glans penis was pulsatile. Parents of the patient did not want any surgery and patient has been in follow‑up. Diagnosis of the vascular lesions on glans penis is very easy by physical and radiological examinations today. Long‑term follow‑up is very important for AVM. Clinicians must make a careful effort to document new glans lesions in the pediatric population and decrease anxiety in the parents of affected children.Key words: Arteriovenous malformations, glans penis, penis anomalie
Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses
The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined
The day-of-the-week effect on stock-market volatility and return: Evidence from emerging markets
This study investigates day-of-the-week (DOW) anomalies in the stock markets of twenty emerging economies. The authors use a modified exponential generalized autoregressive conditional heteroskedasticity in-mean (EGARCH-M) modeling strategy that allows for the simultaneous examination of DOW effects on market return and variability. The effects on both are limited in the authors' sample. To summarize, DOW effects are present in market returns for only three countries, in market volatility for only five countries, and they are present in both for only one country, when the estimates are evaluated at the 1 percent significance level. Despite this, at lower levels of significance the common qualitative patterns in the estimates are extracted such that the higher returns are concentrated around Fridays, whereas volatility is highest on Mondays and lowest on Tuesdays and Fridays
Metabolic determinants of cancer cell sensitivity to glucose limitation and biguanides
As the concentrations of highly consumed nutrients, particularly glucose, are generally lower in tumours than in normal tissues1,2, cancer cells must adapt their metabolism to the tumour microenvironment. A better understanding of these adaptations might reveal cancer cell liabilities that can be exploited for therapeutic benefit. Here, we developed a continuous flow culture apparatus (Nutrostat) for maintaining proliferating cells in low nutrient media for long periods of time and used it to undertake competitive proliferation assays on a pooled collection of barcoded cancer cell lines cultured in low glucose conditions. Sensitivity to low glucose varies amongst cell lines, and an RNAi screen pinpointed mitochondrial oxidative phosphorylation (OXPHOS) as the major pathway required for optimal proliferation in low glucose. We found that cell lines most sensitive to low glucose are defective in the upregulation of OXPHOS normally caused by glucose limitation as a result of either mtDNA mutations in Complex I genes or impaired glucose utilization. These defects predict sensitivity to biguanides, anti-diabetic drugs that inhibit OXPHOS3,4, when cancer cells are grown in low glucose or as tumour xenografts. Remarkably, the biguanide sensitivity of cancer cells with mtDNA mutations was reversed by ectopic expression of yeast NDI1, a ubiquinone oxidoreductase that allows bypass of Complex I function5. Thus, we conclude that mtDNA mutations and impaired glucose utilization are potential biomarkers for identifying tumours with increased sensitivity to OXPHOS inhibitors
Gamma radiation induces hydrogen absorption by copper in water
One of the most intricate issues of nuclear power is the long-term safety of repositories for radioactive waste. These repositories can have an impact on future generations for a period of time orders of magnitude longer than any known civilization. Several countries have considered copper as an outer corrosion barrier for canisters containing spent nuclear fuel. Among the many processes that must be considered in the safety assessments, radiation induced processes constitute a key-component. Here we show that copper metal immersed in water uptakes considerable amounts of hydrogen when exposed to γ-radiation. Additionally we show that the amount of hydrogen absorbed by copper depends on the total dose of radiation. At a dose of 69 kGy the uptake of hydrogen by metallic copper is 7 orders of magnitude higher than when the absorption is driven by H2(g) at a pressure of 1 atm in a non-irradiated dry system. Moreover, irradiation of copper in water causes corrosion of the metal and the formation of a variety of surface cavities, nanoparticle deposits, and islands of needle-shaped crystals. Hence, radiation enhanced uptake of hydrogen by spent nuclear fuel encapsulating materials should be taken into account in the safety assessments of nuclear waste repositories.Peer reviewe
Tumor growth suppression induced by biomimetic silk fibroin hydrogels
Protein-based hydrogels with distinct conformations which enable encapsulation or differentiation of
cells are of great interest in 3D cancer research models. Conformational changes may cause macroscopic
shifts in the hydrogels, allowing for its use as biosensors and drug carriers. In depth knowledge on
how 3D conformational changes in proteins may affect cell fate and tumor formation is required. Thus,
this study reports an enzymatically crosslinked silk fibroin (SF) hydrogel system that can undergo
intrinsic conformation changes from random coil to β-sheet conformation. In random coil status, the
SF hydrogels are transparent, elastic, and present ionic strength and pH stimuli-responses. The random
coil hydrogels become β-sheet conformation after 10 days in vitro incubation and 14 days in vivo
subcutaneous implantation in rat. When encapsulated with ATDC-5 cells, the random coil SF hydrogel
promotes cell survival up to 7 days, whereas the subsequent β-sheet transition induces cell apoptosis
in vitro. HeLa cells are further incorporated in SF hydrogels and the constructs are investigated in vitro
and in an in vivo chick chorioallantoic membrane model for tumor formation. In vivo, Angiogenesis and
tumor formation are suppressed in SF hydrogels. Therefore, these hydrogels provide new insights for
cancer research and uses of biomaterials.The authors would like to thank the Portuguese Foundation for Science and Technology (FCT) project grants OsteoCart (PTDC/CTM-BPC/115977/2009) and Tissue2Tissue (PTDC/CTM/105703/2008) which supported this study. Research leading to these results has also received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no REGPOT-CT2012-316331-POLARIS. Le-Ping Yan was awarded a PhD scholarship from FCT (SFRH/BD/64717/2009). We also would like to thank FCT for the distinction attributed to J.M. Oliveira under the Investigador FCT program (IF/00423/2012). The authors also like to acknowledge Dr. Mariana B. Oliveira for technical assistance on the dynamic mechanical analysis of the cell-laden hydrogels
In vitro phosphorylation as tool for modification of silk and keratin fibrous materials
An overview is given of the recent work on in vitro enzymatic phosphorylation of silk fibroin and human hair keratin. Opposing to many chemical "conventional" approaches, enzymatic phosphorylation is in fact a mild reaction and the treatment falls within "green chemistry" approach. Silk and keratin are not phosphorylated in vivo, but in vitro. This enzyme-driven modification is a major technological breakthrough. Harsh chemical chemicals are avoided, and mild conditions make enzymatic phosphorylation a real "green chemistry" approach. The current communication presents a novel approach stating that enzyme phosphorylation may be used as a tool to modify the surface charge of biocompatible materials such as keratin and silk
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