Publications by authors named "Jahangeer S"

Background: Cardiovascular disease is the leading cause of mortality worldwide, affecting ~1.28 billion adults, and ~46% of these adults are not aware of their condition. One-third of patients do not receive appropriate care for their cardiovascular disease.

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Introduction: The SARS-CoV-2 coronavirus disease 2019 (COVID-19) pandemic has disrupted healthcare services worldwide. Outpatient services have necessarily been restructured to accommodate COVID-19 patients and to maintain social distancing measures. The aim of our study was to investigate how the COVID-19 pandemic has affected outpatient healthcare provision for patients with aortovascular disease.

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Introduction: This study aimed at determining the frequency and association of stress levels with modes of transportation and was likely to reveal the contributing transportation-related factors for stress in medical students.

Methods: This was a questionnaire-based, cross-sectional study that included undergraduate medical students of a public sector medical university in Karachi, Pakistan. A total of 573 students participated voluntarily, of which 300 were provided a manual questionnaire and 273 filled it online.

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An aneurysm of an aberrant subclavian artery is un usual prevalence of anomalies of aortic arch, with a literature reported prevalence of 2%. Timely elective intervention is of paramount. The advancement in stenting techniques has promoted this practice to be an alternative to conventional open surgical repair which is associated with high rates of perioperative complications including mortality outcomes.

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Cardiovascular surgeons have long debated the safe duration of deep hypothermic circulatory arrest during thoracic aortic aneurysm surgery. The rationale for using adjunctive cerebral perfusion (or not) is to achieve the best technical aortic repair with the lowest risk of morbidity and death. In this literature review, we highlight the debates surrounding these issues, evaluate the disparate findings on deep hypothermic circulatory arrest durations and temperatures, and consider the usefulness of adjunctive perfusion.

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Purulent pericarditis is a rare entity in the postantibiotic era. It usually occurs in patients who have underlying chronic and immunosuppressing conditions and its presentation in the healthy adult population is quite rare. Infection of the pericardial space can occur via direct extension from infectious endocarditis, pneumonia, or empyema, or from a more distant source such as meningitis.

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Approximately 1.6 million new cases of lung cancer are diagnosed annually (Jemal et al. CA: A Cancer Journal for Clinicians, 61, 69-90, 2011) and it remains the leading cause of cancer-related mortality worldwide.

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Background Coronary artery aneurysm (CAA) is a rare finding, being mostly diagnosed on angiography or at autopsies. It is defined as being a dilation of the coronary artery that exceeds the diameter of the patient's largest coronary vessel by 1.5 to 2 times.

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Site specific targeting remains elusive for gene and stem cell therapies in the cardiovascular field. One promising option involves use of devices that deliver larger and more sustained cell/gene payloads to specific disease sites using the versatility of percutaneous vascular access technology. Smooth muscle cells (SMCs) engineered to deliver high local concentrations of an angiogenic molecule (VEGF) were placed in an intravascular cell delivery device (ICDD) in a porcine model of chronic total occlusion (CTO) involving ameroid placement on the proximal left circumflex (LCx) artery.

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Tumor interstitial pressure is a fundamental feature of cancer biology. Elevation in tumor pressure affects the efficacy of cancer treatment. It causes heterogenous intratumoral distribution of drugs and macromolecules.

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Lung cancer remains the most common cancer diagnosed worldwide and has one of the lowest survival rates of all cancers. Surgery remains the only curative treatment option but because most patients are either diagnosed at advanced stages or are unfit for surgery, less than a third of all lung cancer patients will undergo a surgical resection. Thermal ablation has emerged as an alternative option in patients who are unfit to undergo surgery.

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Bronchopleural fistula (BPF) is a life threatening complication after pneumonectomy with an incidence of about 2-5% and a mortality rate of up to 50%. Topical treatment such as fibrin glue has been previously described with limited success. We present a novel case in which blocking the phrenic nerve assisted in a successful topical closure of the BPF.

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Although the hippocampus is a brain region involved in short-term memory, the molecular mechanisms underlying memory formation are not completely understood. Here we show that sphingosine 1-phosphate (S1P) plays a pivotal role in the formation of memory. Addition of S1P to rat hippocampal slices increased the rate of AMPA receptor-mediated miniature excitatory postsynaptic currents (mEPSCs) recorded from the CA3 region of the hippocampus.

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Our previous report showed that inhibition of sphingosine kinase (SphK) ameliorates eosinophilic inflammation and mucin production in a mouse asthmatic model. To clarify the role of SphK in airway mucin production, we utilized the mouse asthmatic model and found that both SphK and MUC5AC expression were increased and co-localized in airway epithelium. Next we cultured normal human bronchial epithelial cells in an air-liquid interface and treated with IL-13 to induce their differentiation into goblet cells.

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Sphingosine 1-phosphate (S1P) is an important factor for the regulation of cell motility acting both inside and outside the cells. The precise role of S1P in the control of cell motility, however, remains unclear. Here we describe the roles of S1P in the regulation of cell motility by dissecting them into intracellular and extracellular actions using a liposomal S1P transfer technique.

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Vesicular trafficking such as macropinocytosis is a dynamic process that requires coordinated interactions between specialized proteins and lipids. A recent report suggests the involvement of CtBP1/BARS in epidermal growth factor (EGF)-induced macropinocytosis. Detailed mechanisms as to how lipid remodelling is regulated during macropinocytosis are still undefined.

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Sphingolipids were once regarded as inert structural components of cell membranes. Now these metabolites are generally believed to be important bioactive molecules that control a wide repertoire of cellular processes such as proliferation and survival of cells. Along with these ubiquitous cell functions observed in many peripheral tissues sphingolipid metabolites, especially sphingosine 1-phosphate, exert important neuron-specific functions such as regulation of neurotransmitter release.

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Sphingosine 1-phosphate (S1P) produced by sphingosine kinase (SPHK) is implicated in acute immunoresponses, however, mechanisms of SPHK/S1P signaling in the pathogenesis of bronchial asthma are poorly understood. In this study, we hypothesized that SPHK inhibition could ameliorate lung inflammation in ovalbumin (OVA)-challenged mouse lungs. Six- to eight-week-old C57BL/6J mice were sensitized and exposed to OVA for 3 consecutive days.

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Although organelles such as the endoplasmic reticulum and Golgi apparatus are highly compartmentalized, these organelles are interconnected through a network of vesicular trafficking. The marine sponge metabolite ilimaquinone (IQ) is known to induce Golgi membrane fragmentation and is widely used to study the mechanism of vesicular trafficking. Although IQ treatment causes protein kinase D (PKD) activation, the detailed mechanism of IQ-induced Golgi membrane fragmentation remains unclear.

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Sphingosine kinase (SPHK) is a key enzyme producing important messenger sphingosine 1-phosphate and is implicated in cell proliferation and suppression of apoptosis. Because the extent of agonist-induced activation of SPHK is modest, signaling via SPHK may be regulated through its localization at specific intracellular sites. Although the SPHK1 isoform has been extensively studied and characterized, the regulation of expression and function of the other isoform, SPHK2, remain largely unexplored.

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Neuronal activity greatly influences the formation and stabilization of synapses. Although receptors for sphingosine-1-phosphate (S1P), a lipid mediator regulating diverse cellular processes, are abundant in the central nervous system, neuron-specific functions of S1P remain largely undefined. Here, we report two novel actions of S1P using primary hippocampal neurons as a model system: (i) as a secretagogue where S1P triggers glutamate secretion and (ii) as an enhancer where S1P potentiates depolarization-evoked glutamate secretion.

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Sphingosine kinase (SPHK) 1 is implicated in the regulation of cell proliferation and anti-apoptotic processes by catalyzing the formation of an important bioactive messenger, sphingosine 1-phosphate. Unlike the proliferative action of SPHK1, another isozyme, SPHK2, has been shown to possess anti-proliferative or pro-apoptotic action. Molecular mechanisms of SPHK2 action, however, are largely unknown.

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Sphingosine kinase (SPHK) is a key enzyme catalysing the formation of sphingosine 1-phosphate (SPP), a lipid messenger that is implicated in the regulation of a wide variety of important cellular events acting through intracellular, as well as extracellular, mechanisms. However, the molecular mechanism of intracellular actions of SPP remains unclear. Here, we have identified delta-catenin/NPRAP (neural plakophilin-related armadillo repeat protein) as a potential binding partner for SPHK1 by yeast two-hybrid screening.

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Sphingosine kinase-1 (SPHK1) is a key enzyme catalyzing the formation of an important bioactive lipid messenger, sphingosine 1-phosphate, and is implicated in the regulation of cell proliferation and antiapoptotic processes. Biological features of another isozyme SPHK2, however, remain unclear. The present studies were undertaken to characterize SPHK2 by comparison with SPHK1.

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