Publications by authors named "Ammer A"

Introduction  At the start of the COVID-19 pandemic, many graduate medical education (GME) programs switched from in-person to virtual training to ensure a safe learning environment. However, the preferences of US residents in the wake of the COVID-19 pandemic are largely unknown. Objective The authors surveyed PGY-2 psychiatry residents about their perception of the pandemic's impact on their clinical skills, didactics experience, training preferences, and future career perceptions.

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In response to external stimuli during immune responses, monocytes can have multifaceted roles such as pathogen clearance and tissue repair. However, aberrant control of monocyte activation can result in chronic inflammation and subsequent tissue damage. Granulocyte-macrophage colony-stimulating factor (GM-CSF) induces monocyte differentiation into a heterogenous population of monocyte-derived dendritic cells (moDCs) and macrophages.

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Background: An impairment of standard echocardiographic parameters of right ventricular (RV) function is a known phenomenon in patients undergoing cardiac surgery, but its significance remains unclear.

Aims: This study aimed to assess changes in RV function in patients undergoing cardiac surgery using speckle tracking and 3D echocardiography.

Methods: The study population comprised 122 patients referred for cardiac surgery.

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Signal tranducer and activator of transcription 5 (STAT5) plays a critical role in mediating cellular responses following cytokine stimulation. STAT proteins critically signal via the formation of dimers, but additionally, STAT tetramers serve key biological roles, and we previously reported their importance in T and natural killer (NK) cell biology. However, the role of STAT5 tetramerization in autoimmune-mediated neuroinflammation has not been investigated.

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Background: Missense mutations in the hyperpolarization-activated cyclic nucleotide-modulated (HCN) channel 4 (HCN4) are one of the genetic causes of cardiac sinus bradycardia.

Objective: To investigate possible HCN4 channel mutation in a young patient with profound sinus bradycardia.

Methods: Direct sequencing of and whole-exome sequencing were performed on DNA samples from the indexed patient (P), the patient's son (PS), and a family unrelated healthy long-distance running volunteer (V).

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B-cell acute lymphoblastic leukemia (ALL) affects both pediatric and adult patients. Chemotherapy resistant tumor cells that contribute to minimal residual disease (MRD) underlie relapse and poor clinical outcomes in a sub-set of patients. Targeting mitochondrial oxidative phosphorylation (OXPHOS) in the treatment of refractory leukemic cells is a potential novel approach to sensitizing tumor cells to existing standard of care therapeutic agents.

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Numerous studies have implicated changes in the Y chromosome in male cancers, yet few have investigated the biological importance of Y chromosome noncoding RNA. Here we identify a group of Y chromosome-expressed long noncoding RNA (lncRNA) that are involved in male non-small cell lung cancer (NSCLC) radiation sensitivity. Radiosensitive male NSCLC cell lines demonstrated a dose-dependent induction of following irradiation, which was not observed in radioresistant male NSCLC cell lines.

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Background: Unlike other breast cancer subtypes that may be treated with a variety of hormonal or targeted therapies, there is a need to identify new, effective targets for triple-negative breast cancer (TNBC). It has recently been recognized that membrane potential is depolarized in breast cancer cells. The primary objective of the study is to explore whether hyperpolarization induced by opening potassium channels may provide a new strategy for treatment of TNBC.

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Introduction: Stroke-associated pneumonia (SAP) is a major cause of mortality in patients who have suffered from severe ischemic stroke. Although multifactorial in nature, stroke-induced immunosuppression plays a key role in the development of SAP. Previous studies using a murine model of transient middle cerebral artery occlusion (tMCAO) have shown that focal ischemic stroke induction results in functional defects of lymphocytes in the spleen, thymus, and peripheral blood, leading to spontaneous bacterial infection in the lungs without inoculation.

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Background: Glyceollins are isoflavonoid-derived pathogen-inducible defense metabolites (phytoalexins) from soybean (Glycine max L. Merr) that have important roles in providing defense against pathogens. They also have impressive anticancer and neuroprotective activities in mammals.

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Malregulation of the actin cytoskeleton enhances tumor cell motility and invasion. The actin-binding protein cortactin facilitates branched actin network formation through activation of the actin-related protein (Arp) 2/3 complex. Increased cortactin expression due to gene amplification is observed in head and neck squamous cell carcinoma (HNSCC) and other cancers, corresponding with elevated tumor progression and poor patient outcome.

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Background: Human triple-negative breast cancer has limited therapeutic choices. Breast tumor cells have depolarized plasma membrane potential. Using this unique electrical property, we aim to develop an effective selective killing of triple-negative breast cancer.

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Background: The lack of translatable in vitro blood-tumor barrier (BTB) models creates challenges in the development of drugs to treat tumors of the CNS and our understanding of how the vascular changes at the BBB in the presence of a tumor.

Methods: In this study, we characterize a novel microfluidic model of the BTB (and BBB model as a reference) that incorporates flow and induces shear stress on endothelial cells. Cell lines utilized include human umbilical vein endothelial cells co-cultured with CTX-TNA2 rat astrocytes (BBB) or Met-1 metastatic murine breast cancer cells (BTB).

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The objective of this experiment was to determine effects of peripheral blood mononuclear cells (PBMC), derived from parasite-resistant St. Croix (STC) and parasite-susceptible Suffolk (SF) sheep, on motility of Haemonchus contortus L stage larvae in vitro. Peripheral blood mononuclear cells were collected from 10 lambs of each breed, 5 naïve and 5 which had received a priming infection with H.

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The Kruppel-like transcription factors (KLFs) 4 and 5 (KLF4/5) are coexpressed in mouse embryonic stem cells, where they function redundantly to maintain pluripotency. In mammary carcinoma, KLF4/5 can each impact the malignant phenotype, but potential linkages to drug resistance remain unclear. In primary human breast cancers, we observed a positive correlation between KLF4/5 transcript abundance, particularly in the human epidermal growth factor receptor 2 (HER2)-enriched subtype.

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Aim: To explore the potential usefulness of serum miR-122 and miR-221 as non-invasive diagnostic markers of hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

Methods: This prospective study was conducted on 90 adult patients of both sex with HCV-related chronic liver disease and chronic hepatitis C related HCC. In addition to the 10 healthy control individuals, patients were stratified into; interferon-naïve chronic hepatitis C (CH) (n = 30), post-hepatitis C compensated cirrhosis (LC) (n = 30) and treatment-naïve HCC (n = 30).

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We developed a three-dimensional fibroblastic nodule model for fibrogenicity testing of nanomaterials and investigated the role of fibroblast stemlike cells (FSCs) in the fibrogenic process. We showed that carbon nanotubes (CNTs) induced fibroblastic nodule formation in primary human lung fibroblast cultures resembling the fibroblastic foci in clinical fibrosis and promoted FSCs that are highly fibrogenic and a potential driving force of fibrogenesis. This study provides a predictive 3D model and mechanistic insight on CNT fibrogenesis.

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The paper presents a case report of a patient with a superior vena cava occlusion and post-operational (after the implantation of the aortic valve) atrioventricular block, which required constant stimulation. An epicardial VVI pacemaker was implanted through mini-sternotomy in the lower part of the previous operation field with very satisfactory stimulation parameters. Implantation of a screw-in epicardial lead is in some cases the method of choice, which provides efficient and constant heart stimulation.

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Since the advent of percutaneous coronary intervention there have been increasing numbers of patients with so-called 'full metal jacket' coronary arteries disease. This is creating a challenging problem for the cardiac surgeon. A 73 year-old woman after the implantation of two metal stents to the left anterior descending artery (LAD) and four to the right coronary artery (RCA), with ejection fraction of 28%, significant mitral and tricuspid insufficiency, and high systolic pulmonary pressure, was admitted to our department with unstable angina and with symptoms of pulmonary oedema.

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Head and neck squamous cell carcinoma (HNSCC) has a proclivity for locoregional invasion. HNSCC mediates invasion in part through invadopodia-based proteolysis of the extracellular matrix (ECM). Activation of Src, Erk1/2, Abl and Arg downstream of epidermal growth factor receptor (EGFR) modulates invadopodia activity through phosphorylation of the actin regulatory protein cortactin.

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Tyrosine-kinase-based signal transduction mediated by modular protein domains is critical for cellular function. The Src homology (SH)2 domain is an important conductor of intracellular signaling that binds to phosphorylated tyrosines on acceptor proteins, producing molecular complexes responsible for signal relay. Cortactin is a cytoskeletal protein and tyrosine kinase substrate that regulates actin-based motility through interactions with SH2-domain-containing proteins.

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Cellular invasion into local tissues is a process important in development and homeostasis. Malregulated invasion and subsequent cell movement is characteristic of multiple pathological processes, including inflammation, cardiovascular disease and tumor cell metastasis. Focalized proteolytic degradation of extracellular matrix (ECM) components in the epithelial or endothelial basement membrane is a critical step in initiating cellular invasion.

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Coarctation of the aorta (CoA) is a common congenital anomaly that is usually treated in infancy or childhood. Adult patients with coarctation have a high incidence of associated cardiac disorders, including valve diseases, atrial fibrillation and ischemic heart disease. Most patients with uncorrected CoA die before reaching the age of 50 from complications such as myocardial infarction, intracranial hemorrhage, congestive heart failure (HF), infective endocarditis or aortic dissection.

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The actin regulatory protein cortactin is involved in multiple signaling pathways impinging on the cortical actin cytoskeleton. Cortactin is phosphorylated by ERK1/2 and Src family tyrosine kinases, resulting in neuronal Wiskott Aldrich Syndrome protein (N-WASp) activation and enhanced actin related protein (Arp)2/3-mediated actin nucleation. Cortactin migrates as an 80/85 kDa doublet when analyzed by SDS-PAGE.

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The filamentous (F)-actin regulatory protein cortactin plays an important role in tumor cell movement and invasion by promoting and stabilizing actin related protein (Arp)2/3-mediated actin networks necessary for plasma membrane protrusion. Cortactin is a substrate for ERK1/2 and Src family kinases, with previous in vitro findings demonstrating ERK1/2 phosphorylation of cortactin as a positive and Src phosphorylation as a negative regulatory event in promoting Arp2/3 activation through neuronal Wiskott Aldrich Syndrome protein (N-WASp). Evidence for this regulatory cortactin "switch" in cells has been hampered due to the lack of phosphorylation-specific antibodies that recognize ERK1/2-phosphorylated cortactin.

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