84 research outputs found
Detection of monosomy 7 in interphase cells of patients with myeloid disorders
Six patients, five with acute myeloid leukemia (AML) and one with a myelodysplastic syndrome (MDS), were found to have monosomy 7 by conventional cytogenetics at diagnosis. Repetitive DNA sequences from the heterochromatic region of human chromosomes 1 and 7 were used as probes for in situ hybridization experiments on interphase cells of these patients. A double hybridization protocol was used to reveal the particular chromosomes as distinct spots or clusters of signals within interphase nuclei. The chromosome 1 sequence served as an internal control. Simultaneous detection of the sequences showed the presence of two normal number 1 chromosomes and a missing 7 chromosome from individual cells. While cytogenetic preparations showed only -7 metaphases in 3 AML and 1 MDS patients, in situ hybridization of interphase cells showed many normal cells as well as the presence of -7 in fully mature granulocytes. One AML patient studied in remission showed only normal metaphases yet had 9% interphase cells with a missing 7 and relapsed within 3 months. We conclude that examination of interphase cells by in situ hybridization provides clinically useful data since every cell including mature granulocytes can be examined, the lineage of a cell can be determined, and efficacy of differentiation therapy can be evaluated
Considerations to Model Heart Disease in Women with Preeclampsia and Cardiovascular Disease
Preeclampsia is a multifactorial cardiovascular disorder diagnosed after 20 weeks of gestation, and is the leading cause of death for both mothers and babies in pregnancy. The pathophysiology remains poorly understood due to the variability and unpredictability of disease manifestation when studied in animal models. After preeclampsia, both mothers and offspring have a higher risk of cardiovascular disease (CVD), including myocardial infarction or heart attack and heart failure (HF). Myocardial infarction is an acute myocardial damage that can be treated through reperfusion; however, this therapeutic approach leads to ischemic/reperfusion injury (IRI), often leading to HF. In this review, we compared the current in vivo, in vitro and ex vivo model systems used to study preeclampsia, IRI and HF. Future studies aiming at evaluating CVD in preeclampsia patients could benefit from novel models that better mimic the complex scenario described in this article
Towards engineering heart tissues from bioprinted cardiac spheroids.
Currentin vivoandin vitromodels fail to accurately recapitulate the human heart microenvironment for biomedical applications. This study explores the use of cardiac spheroids (CSs) to biofabricate advancedin vitromodels of the human heart. CSs were created from human cardiac myocytes, fibroblasts and endothelial cells (ECs), mixed within optimal alginate/gelatin hydrogels and then bioprinted on a microelectrode plate for drug testing. Bioprinted CSs maintained their structure and viability for at least 30 d after printing. Vascular endothelial growth factor (VEGF) promoted EC branching from CSs within hydrogels. Alginate/gelatin-based hydrogels enabled spheroids fusion, which was further facilitated by addition of VEGF. Bioprinted CSs contracted spontaneously and under stimulation, allowing to record contractile and electrical signals on the microelectrode plates for industrial applications. Taken together, our findings indicate that bioprinted CSs can be used to biofabricate human heart tissues for long termin vitrotesting. This has the potential to be used to study biochemical, physiological and pharmacological features of human heart tissue
Causes of death and comorbidities in hospitalized patients with COVID-19
Infection by the new corona virus strain SARS-CoV-2 and its related syndrome COVID-19 has been associated with more than two million deaths worldwide. Patients of higher age and with preexisting chronic health conditions are at an increased risk of fatal disease outcome. However, detailed information on causes of death and the contribution of pre-existing health conditions to death yet is missing, which can be reliably established by autopsy only. We performed full body autopsies on 26 patients that had died after SARS-CoV-2 infection and COVID-19 at the Charite University Hospital Berlin, Germany, or at associated teaching hospitals. We systematically evaluated causes of death and pre-existing health conditions. Additionally, clinical records and death certificates were evaluated. We report findings on causes of death and comorbidities of 26 decedents that had clinically presented with severe COVID-19. We found that septic shock and multi organ failure was the most common immediate cause of death, often due to suppurative pulmonary infection. Respiratory failure due to diffuse alveolar damage presented as immediate cause of death in fewer cases. Several comorbidities, such as hypertension, ischemic heart disease, and obesity were present in the vast majority of patients. Our findings reveal that causes of death were directly related to COVID-19 in the majority of decedents, while they appear not to be an immediate result of preexisting health conditions and comorbidities. We therefore suggest that the majority of patients had died of COVID-19 with only contributory implications of preexisting health conditions to the mechanism of death
Structure, mechanism, and inhibition of Hedgehog acyltransferase
The Sonic Hedgehog (SHH) morphogen pathway is fundamental for embryonic development and stem cell maintenance and is implicated in various cancers. A key step in signaling is transfer of a palmitate group to the SHH N terminus, catalyzed by the multi-pass transmembrane enzyme Hedgehog acyltransferase (HHAT). We present the high-resolution cryo-EM structure of HHAT bound to substrate analog palmityl-coenzyme A and a SHH-mimetic megabody, revealing a heme group bound to HHAT that is essential for HHAT function. A structure of HHAT bound to potent small-molecule inhibitor IMP-1575 revealed conformational changes in the active site that occlude substrate binding. Our multidisciplinary analysis provides a detailed view of the mechanism by which HHAT adapts the membrane environment to transfer an acyl chain across the endoplasmic reticulum membrane. This structure of a membrane-bound O-acyltransferase (MBOAT) superfamily member provides a blueprint for other protein-substrate MBOATs and a template for future drug discovery
Minus-two: Multimedia, sound spatialization and 3D representation for cognitively impaired children
Multimedia and Hypermedia technologies can be successfully used in education and rehabilitation for cognitively disabled persons. In particular, storytelling has always proved successfully in creating imaginary worlds that could both protect the child from the difficulties of the outer world and create the conditions to feed new stimuli without causing discomfort. However, traditional storytelling techniques (paper, pencil, the voice of the teacher) sometimes might be vastly improved by using multimedia and hypermedia technologies. The possibility to play different music, to explore spatialized sounds, to record sounds and voices, and the opportunity to play with 3D images within a 3D space using devices as simple as touch screens, may ensure an enhanced level of attention from the children and may give to the teacher new and powerful tools to convey his/her message through the common activity. In this paper we motivate the use of hypermedia educational techniques with cognitively impaired children, outlining the general requirements of an educational framework that might be provided to teachers. We then describe the functioning of a prototype we developed following these requirements, MINUS-TWO: a storytelling environment mainly characterized by a strict cooperation between the child and the teacher or the therapist, by multimodal interaction, sound spatialization and 3D representation. The paper also presents the results we obtained by using these techniques with more than twenty cognitively impaired children
General material properties of Denizli (SW Turkey) travertines as a building stone
The quality and material properties of Denizli travertine as a natural building stone have been investigated. The Denizli region is one of the world's major travertine deposits and production basins. Travertine blocks are extracted from over fifty quarries in the region. In this study, investigations and evaluations of experimental test results of travertine samples from six areas (Kakli{dotless}k-Kocabaş, Honaz-Emirazizli, Aşagi{dotless}dagdere, Akköy, Karaçay and Çivril), which represent the entire Denizli basin, are presented. Kakli{dotless}k-Kocabaş is the biggest production area in the region, and therefore most of the quarries are located in this area. Physical, mechanical, micro-structural and macro-structural properties of the travertine samples are evaluated within the scope of stone quality assessment. Variations of test results by area are presented, and correlations between them are proposed. Test results are also compared with the results of various studies from Turkey and other parts of the world. © 2013 Springer-Verlag Berlin Heidelberg
General material properties of Denizli (SW Turkey) travertines as a building stone
The quality and material properties of Denizli travertine as a natural building stone have been investigated. The Denizli region is one of the world's major travertine deposits and production basins. Travertine blocks are extracted from over fifty quarries in the region. In this study, investigations and evaluations of experimental test results of travertine samples from six areas (Kakli{dotless}k-Kocabaş, Honaz-Emirazizli, Aşaǧi{dotless}daǧdere, Akköy, Karaçay and Çivril), which represent the entire Denizli basin, are presented. Kakli{dotless}k-Kocabaş is the biggest production area in the region, and therefore most of the quarries are located in this area. Physical, mechanical, micro-structural and macro-structural properties of the travertine samples are evaluated within the scope of stone quality assessment. Variations of test results by area are presented, and correlations between them are proposed. Test results are also compared with the results of various studies from Turkey and other parts of the world. © 2013 Springer-Verlag Berlin Heidelberg
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