Publications by authors named "Shama Ahmad"

Article Synopsis
  • Airways and alveoli are particularly susceptible to toxic chemical exposure, but the lungs have effective protective mechanisms to maintain function.
  • Alveolar macrophages act as the primary defense by combating pathogens and harmful substances that penetrate the airway barrier.
  • Recent studies are focusing on alveolar macrophages as therapeutic targets to understand their role in disease development, especially concerning chemical-induced acute lung injury.
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Myocardial sarcoendoplasmic reticulum calcium ATPase 2 (SERCA2) activity is critical for heart function. We have demonstrated that inhaled halogen (chlorine or bromine) gases inactivate SERCA2, impair calcium homeostasis, increase proteolysis, and damage the myocardium ultimately leading to cardiac dysfunction. To further elucidate the mechanistic role of SERCA2 in halogen-induced myocardial damage, we used bromine-exposed cardiac-specific SERCA2 knockout (KO) mice [tamoxifen-administered SERCA2 ( Tg (MHC-MerCreMer) mice] and compared them to the oil-administered controls.

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Burn injuries including those caused by chemicals can result in systemic effects and acute lung injury (ALI). Cutaneous exposure to Lewisite, a warfare and chemical burn agent, also causes ALI. To overcome the limitations in conducting direct research on Lewisite-induced ALI in a laboratory setting, an animal model was developed using phenylarsine oxide (PAO) as a surrogate for Lewisite.

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Hummus is a traditional and very popular Mediterranean ready-to-eat (RTE) food, with growing popularity worldwide. However, it has a high water activity and is susceptible to microbial growth and post-process contamination that limit its quality and shelf-life. For this purpose, the present study compared the use of several antimicrobials, alone or in combination, for hummus preservation during storage (4 °C), for up to 45 days.

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Pulmonary disease such as chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis and pulmonary hypertension are the leading cause of deaths. More importantly, lung diseases are on the rise and environmental factors induced epigenetic modifications are major players on this increased prevalence. It has been reported that dysregulation of genes involved in epigenetic regulation such as the histone deacetylase (HDACs) and histone acetyltransferase (HATs) play important role in lung health and pulmonary disease pathogenesis.

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Arsenic trioxide (ATO), an inorganic arsenical, is a toxic environmental contaminant. It is also a widely used chemical with industrial and medicinal uses. Significant public health risk exists from its intentional or accidental exposure.

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Accidental occupational bromine (Br>) exposures are common, leading to significant morbidity and mortality; however, the specific effects of Br> inhalation in female victims are unclear. Our studies demonstrated that acute high-concentration Br> inhalation is fatal, and cardiac injury and dysfunction play an important role in Br> toxicity in males. In this study, we exposed female Sprague Dawley rats, age-matched to those males from previously studied, to 600 ppm Br> for 45 min and assessed their survival, cardiopulmonary injury and cardiac function after exposure.

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Pulmonary arterial hypertension (PAH) is a progressive proliferative vasculopathy associated with mechanical and electrical changes, culminating in increased vascular resistance, right ventricular (RV) failure, and death. With a main focus on invasive tools, there has been an underutilization of echocardiography, electrocardiography, and biomarkers to non-invasively assess the changes in myocardial and pulmonary vascular structure and function during the course of PAH. A SU5416-hypoxia rat model was used for inducing PAH.

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The recent emergence of a novel coronavirus, SARS-CoV-2, has led to the global pandemic of the severe disease COVID-19 in humans. While efforts to quickly identify effective antiviral therapies have focused largely on repurposing existing drugs , the current standard of care, remdesivir, remains the only authorized antiviral intervention of COVID-19 and provides only modest clinical benefits . Here we show that water-soluble derivatives of α-tocopherol have potent antiviral activity and synergize with remdesivir as inhibitors of the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp).

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The risk of accidental bromine (Br) exposure to the public has increased due to its enhanced industrial use. Inhaled Br damages the lungs and the heart; however, adverse effects on the brain are unknown. In this study, we examined the neurological effects of inhaled Br in Sprague Dawley rats.

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Inflammation is an essential component of several respiratory diseases, such as chronic obstructive pulmonary disease (COPD), asthma and acute respiratory distress syndrome (ARDS). It is central to lung cancer, the leading cancer in terms of associated mortality that has affected millions of individuals worldwide. Inflammation and pulmonary manifestations are also the major causes of COVID-19 related deaths.

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Objective: Acute kidney injury (AKI) is a common complication of complex aortic surgery with high mortality, morbidity and health care expense. The current definition of AKI does not allow for structural characterization of the kidneys and utilizes functional indices with substantial limitations leading to delayed diagnosis and ineffective interventions. The aim of this study is to develop a method of early detection of structural renal abnormalities that can precede and predict the occurrence of AKI in this population.

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Accidental bromine spills are common and its large industrial stores risk potential terrorist attacks. The mechanisms of bromine toxicity and effective therapeutic strategies are unknown. Our studies demonstrate that inhaled bromine causes deleterious cardiac manifestations.

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The threat from deliberate or accidental exposure to halogen gases is increasing, as is their industrial applications and use as chemical warfare agents. Biomarkers that can identify halogen exposure, diagnose victims of exposure or predict injury severity, and enable appropriate treatment are lacking. We conducted these studies to determine and validate biomarkers of bromine (Br ) toxicity and correlate the symptoms and the extent of cardiopulmonary injuries.

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Exposure of rats to 2-chloroethyl ethyl sulfide (CEES), an analog of sulfur mustard, can cause acute lung injury (ALI), resulting in increased inflammation and coagulation and altered levels of plasma microRNAs (miRNAs). Rats were exposed to aerosolized CEES and euthanized 12 h later for collection of tissue and plasma. Profiling of miRNAs in plasma, using a TaqMan-based RT-PCR array, revealed 14 differentially expressed miRNAs.

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Lewisite is a strong vesicating and chemical warfare agent. Because of the rapid transdermal absorption, cutaneous exposure to lewisite can also elicit severe systemic injury. Lewisite (2.

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Article Synopsis
  • Sulfur mustard (SM) is a deadly chemical weapon causing severe health issues, and there is currently no effective treatment for exposure.
  • In a study with rats exposed to a related compound, CEES, researchers found that treatment with hexadimethrine bromide (HDMBr) significantly reduced lung injury and inflammation caused by the exposure.
  • HDMBr not only improved survival rates and lung function but also demonstrated potential as a therapeutic agent by neutralizing extracellular nucleic acids (eNA) that contribute to the inflammatory response in SM toxicity.
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Halogens are widely used, highly toxic chemicals that pose a potential threat to humans because of their abundance. Halogens such as bromine (Br) cause severe pulmonary and systemic injuries; however, the mechanisms of their toxicity are largely unknown. Here, we demonstrated that Br and reactive brominated species produced in the lung and released in blood reach the heart and cause acute cardiac ultrastructural damage and dysfunction in rats.

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Article Synopsis
  • Nicotine is absorbed into the bloodstream and is a key addictive element in both traditional tobacco and e-cigarettes, but its isolated effects on health are not well understood.
  • Research using a rat model exposed to aerosolized nicotine revealed significant lung injury indicators, including increased lung inflammation and damage, as well as changes in blood cell counts.
  • Nicotine exposure in airway epithelial cells showed detrimental effects, such as barrier loss and increased cell death, suggesting that nicotine from e-cigarettes could lead to serious pulmonary and systemic health issues.
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Cell therapy has the potential to cure disease through replacement of malfunctioning cells. Although the tissue stem cell (TSC) is thought to be the optimal therapeutic cell, transplantation of TSC/progenitor cell mixtures has saved lives. We previously purified the mouse tracheobronchial epithelial TSCs and reported that in vitro amplification generated numerous TSCs.

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Objective: Recent studies have demonstrated improved outcomes in patients receiving early surgery for degenerative mitral regurgitation (MR) rather than adhering to conventional guidelines for surgical intervention. However, studies providing a mechanistic basis for these findings are limited.

Methods: Left ventricular (LV) myocardium from 22 patients undergoing mitral valve repair for American Heart Association class I indications was evaluated for desmin, the voltage-dependent anion channel, α-B-crystallin, and α, β-unsaturated aldehyde 4-hydroxynonenal by fluorescence microscopy.

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Sulfur mustard (SM; bis-(2-chlororethyl) sulfide) is a highly reactive, potent warfare agent that has recently reemerged as a major threat to military and civilians. Exposure to SM is often fatal, primarily due to pulmonary injuries and complications caused by its inhalation. Profound inflammation, hypercoagulation, and oxidative stress are the hallmarks that define SM-induced pulmonary toxicities.

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Inhalations of atmospheric pollutants, especially particulate matters, are known to cause severe cardiac effects and to exacerbate preexisting heart disease. Heart failure is an important sequellae of gaseous inhalation such as that of carbon monoxide. Similarly, other gases such as sulphur dioxide are known to cause detrimental cardiovascular events.

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