91 research outputs found
Imaging in breast cancer: Diffuse optics in breast cancer: detecting tumors in pre-menopausal women and monitoring neoadjuvant chemotherapy
Diffuse optical spectroscopy (DOS) and diffuse optical imaging (DOI) are non-invasive diagnostic techniques that employ near-infrared (NIR) light to quantitatively characterize the optical properties of centimeter-thick, multiple-scattering tissues. Although NIR was first applied to breast diaphanography more than 70 years ago, quantitative optical methods employing time- or frequency-domain 'photon migration' technologies have only recently been used for breast imaging. Because their performance is not limited by mammographic density, optical methods can provide new insight regarding tissue functional changes associated with the appearance, progression, and treatment of breast cancer, particularly for younger women and high-risk subjects who may not benefit from conventional imaging methods. This paper reviews the principles of diffuse optics and describes the development of broadband DOS for quantitatively measuring the optical and physiological properties of thick tissues. Clinical results are shown highlighting the sensitivity of diffuse optics to malignant breast tumors in 12 pre-menopausal subjects ranging in age from 30 to 39 years and a patient undergoing neoadjuvant chemotherapy for locally advanced breast cancer. Significant contrast was observed between normal and tumor regions of tissue for deoxy-hemoglobin (p = 0.005), oxy-hemoglobin (p = 0.002), water (p = 0.014), and lipids (p = 0.0003). Tissue hemoglobin saturation was not found to be a reliable parameter for distinguishing between tumor and normal tissues. Optical data were converted into a tissue optical index that decreased 50% within 1 week in response to neoadjuvant chemotherapy. These results suggest a potential role for diffuse optics as a bedside monitoring tool that could aid the development of new strategies for individualized patient care
Justified Concern or Exaggerated Fear: The Risk of Anaphylaxis in Percutaneous Treatment of Cystic Echinococcosis—A Systematic Literature Review
Percutaneous treatment (PT) emerged in the mid-1980s as an alternative to surgery for selected cases of abdominal cystic echinococcosis (CE). Despite its efficacy and widespread use, the puncture of echinococcal cysts is still far from being universally accepted. One of the main reasons for this reluctance is the perceived risk of anaphylaxis linked to PTs. To quantify the risk of anaphylactic reactions and lethal anaphylaxis with PT, we systematically searched MEDLINE for publications on PT of CE and reviewed the PT-related complications. After including 124 publications published between 1980 and 2010, we collected a total number of 5943 PT procedures on 5517 hepatic and non-hepatic echinococcal cysts. Overall, two cases of lethal anaphylaxis and 99 reversible anaphylactic reactions were reported. Lethal anaphylaxis occurred in 0.03% of PT procedures, corresponding to 0.04% of treated cysts, while reversible allergic reactions complicated 1.7% of PTs, corresponding to 1.8% of treated echinococcal cysts. Analysis of the literature shows that lethal anaphylaxis related to percutaneous treatment of CE is an extremely rare event and is observed no more frequently than drug-related anaphylactic side effects
Update on Hemicrania Continua
Hemicrania continua (HC) is a rare primary headache syndrome, characterized by unilateral pain and an absolute response to indometacin. Since the term was first coined in 1984, more than 100 cases have been described worldwide. Most recently, detailed case series that provide more detailed information concerning the sometimes complex clinical presentation of HC have been reported. Functional imaging studies suggest a unique pattern of subcortical involvement in HC: contralateral to the pain posterior hypothalamic region, ipsilateral dorsal pons and ipsilateral ventral midbrain, which, along with the particular effect of indometacin, probably justifies its classification as a unique entity. Increasing the awareness of this primary headache form among clinicians will aid in its diagnosis while further work is being undertaken to characterize the syndrome
Yeast thioredoxin reductase Trr1p controls TORC1-regulated processes
The thioredoxin system plays a predominant role in the control of cellular redox status. Thioredoxin reductase fuels the system with reducing power in the form of NADPH. The TORC1 complex promotes growth and protein synthesis when nutrients, particularly amino acids, are abundant. It also represses catabolic processes, like autophagy, which are activated during starvation. We analyzed the impact of yeast cytosolic thioredoxin reductase TRR1 deletion under different environmental conditions. It shortens chronological life span and reduces growth in grape juice fermentation. TRR1 deletion has a global impact on metabolism during fermentation. As expected, it reduces oxidative stress tolerance, but a compensatory response is triggered, with catalase and glutathione increasing. Unexpectedly, TRR1 deletion causes sensitivity to the inhibitors of the TORC1 pathway, such as rapamycin. This correlates with low Tor2p kinase levels and indicates a direct role of Trr1p in its stability. Markers of TORC1 activity, however, suggest increased TORC1 activity. The autophagy caused by nitrogen starvation is reduced in the trr1Δ mutant. Ribosomal protein Rsp6p is dephosphorylated in the presence of rapamycin. This dephosphorylation diminishes in the TRR1 deletion strain. These results show a complex network of interactions between thioredoxin reductase Trr1p and the processes controlled by TOR
A Novel Intravital Method to Evaluate Cerebral Vasospasm in Rat Models of Subarachnoid Hemorrhage: A Study with Synchrotron Radiation Angiography
Precise in vivo evaluation of cerebral vasospasm caused by subarachnoid hemorrhage has remained a critical but unsolved issue in experimental small animal models. In this study, we used synchrotron radiation angiography to study the vasospasm of anterior circulation arteries in two subarachnoid hemorrhage models in rats. Synchrotron radiation angiography, laser Doppler flowmetry-cerebral blood flow measurement, [125I]N-isopropyl-p-iodoamphetamine cerebral blood flow measurement and terminal examinations were applied to evaluate the changes of anterior circulation arteries in two subarachnoid hemorrhage models made by blood injection into cisterna magna and prechiasmatic cistern. Using synchrotron radiation angiography technique, we detected cerebral vasospasm in subarachnoid hemorrhage rats compared to the controls (p<0.05). We also identified two interesting findings: 1) both middle cerebral artery and anterior cerebral artery shrunk the most at day 3 after subarachnoid hemorrhage; 2) the diameter of anterior cerebral artery in the prechiasmatic cistern injection group was smaller than that in the cisterna magna injection group (p<0.05), but not for middle cerebral artery. We concluded that synchrotron radiation angiography provided a novel technique, which could directly evaluate cerebral vasospasm in small animal experimental subarachnoid hemorrhage models. The courses of vasospasm in these two injection models are similar; however, the model produced by prechiasmatic cistern injection is more suitable for study of anterior circulation vasospasm
P2Y12 platelet inhibition in clinical practice
Platelet adhesion, activation and aggregation play a pivotal role in atherothrombosis. Intracoronary atherothrombosis is the most common cause of the development of acute coronary syndrome (ACS), and plays a central role in complications occurring around percutaneous coronary intervention (PCI) including recurrent ACS, procedure-related myocardial infarction or stent thrombosis. Inhibition of platelet aggregation by medical treatment impairs formation and progression of thrombotic processes and is therefore of great importance in the prevention of complications after an ACS or around PCI. An essential part in the platelet activation process is the interaction of adenosine diphosphate (ADP) with the platelet P2Y12 receptor. The P2Y12 receptor is the predominant receptor involved in the ADP-stimulated activation of the glycoprotein IIb/IIIa receptor. Activation of the glycoprotein IIb/IIIa receptor results in enhanced platelet degranulation and thromboxane production, and prolonged platelet aggregation. The objectives of this review are to discuss the pharmacological limitations of the P2Y12 inhibitor clopidogrel, and describe the novel alternative P2Y12 inhibitors prasugrel and ticagrelor and the clinical implications of the introduction of these new medicines
Architectures and biogenesis of non-flagellar protein appendages in Gram-negative bacteria
Bacteria commonly expose non-flagellar proteinaceous appendages on their outer surfaces. These extracellular structures, called pili or fimbriae, are employed in attachment and invasion, biofilm formation, cell motility or protein and DNA transport across membranes. Over the past 15 years, the power of molecular and structural techniques has revolutionalized our understanding of the biogenesis, structure, function and mode of action of these bacterial organelles. Here, we review the five known classes of Gram-negative non-flagellar appendages from a biosynthetic and structural point of view
Stem cells in liver regeneration and therapy
The liver has adapted to the inflow of ingested toxins by the evolutionary development of unique regenerative properties and responds to injury or tissue loss by the rapid division of mature cells. Proliferation of the parenchymal cells, i.e. hepatocytes and epithelial cells of the bile duct, is regulated by numerous cytokine/growth-factor-mediated pathways and is synchronised with extracellular matrix degradation and restoration of the vasculature. Resident hepatic stem/progenitor cells have also been identified in small numbers in normal liver and implicated in liver tissue repair. Their putative role in the physiology, pathophysiology and therapy of the liver, however, is not yet precisely known. Hepatic stem/progenitor cells also known as “oval cells” in rodents have been implicated in liver tissue repair, at a time when the capacity for hepatocyte and bile duct replication is exhausted or experimentally inhibited (facultative stem/progenitor cell pool). Although much more has to be learned about the role of stem/progenitor cells in the physiology and pathophysiology of the liver, experimental analysis of the therapeutic value of these cells has been initiated. Transplantation of hepatic stem/progenitor cells or in vivo pharmacological activation of the pool of hepatic stem cells may provide novel modalities for the therapy of liver diseases. In addition, extrahepatic stem cells (e.g. bone marrow cells) are being investigated for their contribution to liver regeneration. Hepatic progenitor cells derived from embryonic stem cells are included in this review, which also discusses future perspectives of stem cell-based therapies for liver diseases
Italian guidelines for primary headaches: 2012 revised version
The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version
Rising temperatures advance the main flight period of Bombus bumblebees in agricultural landscapes of the Central European Plain
Funder: Poznan University of Life SciencesAbstractThis study examined shifts over a 35-year period in the phenology of the four most important bumblebee species (Bombus terrestris, B. lapidarius, B. pascuorum and B. hortorum) in Central Europe. The species showed similar temporal trends, significantly advancing components of their main flight period in association with rising temperatures such that, for example, mid-dates of the main flight period advanced by 10–23 days over the study period. Drivers of this change differed between the four species. Trends in, and drivers of, the timing of first queens, first workers and first males were less consistent. Aspects of the phenology of the least common species, B. hortorum, were up to a month earlier than the other species and climatic effects less clear cut. There were some suggestions of differences between species trends. These results stress the importance of considering changes and drivers of change for the Bombus family on a species-specific basis with the need to pay more attention to the life history traits of the study organisms.</jats:p
- …
