35 research outputs found
Accidental High Voltage Electrocution: a Case Report
Background: Without electricity, mankind wouldn’t have progressed to the heights we are at now. As much as electricity is helpful, being careless with it can be fatal. The passage of electric current through the body produces wide range of effects, varying from insignificant localised spasm, little or no contact burns, fatality with little or no burns or extreme severe burning.Case Report: This case report discusses the injuries sustained by a young adult, due to accidental contact with high tension wire.Conclusion: This paper also highlights safety rules pertaining to high voltage cables
Comparison of the Transmembrane Mucins MUC1 and MUC16 in Epithelial Barrier Function
Membrane-anchored mucins are present in the apical surface glycocalyx of mucosal epithelial cells, each mucosal epithelium having at least two of the mucins. The mucins have been ascribed barrier functions, but direct comparisons of their functions within the same epithelium have not been done. In an epithelial cell line that expresses the membrane-anchored mucins, MUC1 and MUC16, the mucins were independently and stably knocked down using shRNA. Barrier functions tested included dye penetrance, bacterial adherence and invasion, transepithelial resistance, tight junction formation, and apical surface size. Knockdown of MUC16 decreased all barrier functions tested, causing increased dye penetrance and bacterial invasion, decreased transepithelial resistance, surprisingly, disruption of tight junctions, and greater apical surface cell area. Knockdown of MUC1 did not decrease barrier function, in fact, barrier to dye penetrance and bacterial invasion increased significantly. These data suggest that barrier functions of membrane-anchored mucins vary in the context of other membrane mucins, and MUC16 provides a major barrier when present
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Suppression of Toll-like Receptor-Mediated Innate Immune Responses at the Ocular Surface by the Membrane-associated Mucins MUC1 and MUC16
Membrane-associated mucins (MAMs) expressed on the ocular surface epithelium form a dense glycocalyx, which is hypothesized to protect the cornea and conjunctiva from external insult. In this study, the hypothesis that the MAMs MUC1 and MUC16, expressed on the apical surface of the corneal epithelium, suppress Toll-like receptor (TLR)-mediated innate immune responses was tested. Using an in vitro model of corneal epithelial cells that are cultured to express MAMs, we show that reduced expression of either MUC1 or MUC16 correlates with increased message and secreted protein levels of the proinflammatory cytokines IL-6, IL-8, and TNF-α following exposure of cells to the TLR2 and TLR5 agonists, heat killed Listeria monocytogenes and flagellin, respectively. Since mice express MUC1 (but not MUC16) in the corneal epithelium, a Muc1-/- mouse model was used to extend in vitro findings. Indeed, IL-6 and TNF-α message levels were increased in the corneal epithelium of Muc1-/- mice, in comparison to wild type mice, following exposure of enucleated eyes to the TLR2 and TLR5 agonists. Our results suggest that the MAMs MUC1 and MUC16 contribute to the maintenance of immune homeostasis at the ocular surface by limiting TLR-mediated innate immune responses
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Epidemic Keratoconjunctivitis-Causing Adenoviruses Induce MUC16 Ectodomain Release To Infect Ocular Surface Epithelial Cells
ABSTRACT Human adenoviruses (HAdV), species D in particular (HAdV-D), are frequently associated with epidemic keratoconjunctivitis (EKC). Although the infection originates at the ocular surface epithelium, the mechanisms by which HAdV-Ds bypass the membrane-associated mucin (MAM)-rich glycocalyx of the ocular surface epithelium to trigger infection and inflammation remain unknown. Here, we report that an EKC-causing adenovirus (HAdV-D37), but not a non-EKC-causing one (HAdV-D19p), induces ectodomain release of MUC16—a MAM with barrier functions at the ocular surface—from cultured human corneal and conjunctival epithelial cells. HAdV-D37, but not HAdV-D19p, is also found to decrease the glycocalyx barrier function of corneal epithelial cells, as determined by rose bengal dye penetrance assays. Furthermore, results from quantitative PCR (qPCR) amplification of viral genomic DNA using primers specific to a conserved region of the E1B gene show that, in comparison to infection by HAdV-D19p, infection by HAdV-D37 is significantly increased in corneal epithelial cells. Collectively, these results point to a MUC16 ectodomain release-dependent mechanism utilized by the EKC-causing HAdV-D37 to initiate infection at the ocular surface. These findings are important in terms of understanding the pathogenesis of adenoviral keratoconjunctivitis. Similar MAM ectodomain release mechanisms may be prevalent across other mucosal epithelia in the body (e.g., the airway epithelium) that are prone to adenoviral infection. IMPORTANCE: Human adenoviruses (HAdVs) are double-stranded DNA viruses that cause infections across all mucosal tissues in the body. At the ocular surface, HAdVs cause keratoconjunctivitis (E. Ford, K. E. Nelson, and D. Warren, Epidemiol Rev 9:244–261, 1987, and C. M. Robinson, D. Seto, M. S. Jones, D. W. Dyer, and J. Chodosh, Infect Genet Evol 11:1208–1217, 2011, doi:10.1016/j.meegid.2011.04.031)—a highly contagious infection that accounts for nearly 60% of conjunctivitis cases in the United States (R. P. Sambursky, N. Fram, and E. J. Cohen, Optometry 78:236–239, 2007, doi:10.1016/j.optm.2006.11.012, and A. M. Pihos, J Optom 6:69–74, 2013, doi:10.1016/j.optom.2012.08.003). The infection begins with HAdV entry within ocular surface epithelial cells; however, the mechanisms used by HAdVs to transit the otherwise protective mucosal barrier of ocular surface epithelial cells prior to entry remain unknown. Here, we report that the highly virulent keratoconjunctivitis-causing HAdV-D37 induces release of the extracellular domain (ectodomain) of MUC16, a major component of the mucosal barrier of ocular surface epithelial cells, prior to infecting underlying cells. Currently, there is no specific treatment for controlling this infection. Understanding the early steps involved in the pathogenesis of keratoconjunctivitis and using this information to intercept adenoviral entry within cells may guide the development of novel strategies for controlling the infection
Rare case of chemotherapy-refractory metastatic vaginal squamous cell carcinoma with complete response to concurrent pembrolizumab and radiotherapy- case report and literature review
Primary vaginal cancer is a rare malignancy with a lack of international guidelines and supporting clinical trial evidence to guide decision making. Historical results have shown poor outcomes with chemotherapy for stage IVB vaginal squamous cell carcinoma (SCC). The evolving role of checkpoint inhibitors in rare gynaecological cancers prompted us to investigate the role of pembrolizumab in this setting. The efficacy of pembrolizumab in vaginal SCC has never been investigated in any clinical trial. There is established data to support the use of concurrent chemoradiotherapy in gynaecological cancers, however, the data for concurrent use of immunotherapy and radiotherapy is still lacking but is the subject of several clinical trials. We herein present the first reported case of chemotherapy refractory vaginal SCC with complete response to pembrolizumab and concurrent pelvic radiotherapy. We also present wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) as a rare but new immune related adverse event
A Metalloproteinase Secreted by Streptococcus pneumoniae Removes Membrane Mucin MUC16 from the Epithelial Glycocalyx Barrier
The majority of bacterial infections occur across wet-surfaced mucosal epithelia, including those that cover the eye, respiratory tract, gastrointestinal tract and genitourinary tract. The apical surface of all these mucosal epithelia is covered by a heavily glycosylated glycocalyx, a major component of which are membrane-associated mucins (MAMs). MAMs form a barrier that serves as one of the first lines of defense against invading bacteria. While opportunistic bacteria rely on pre-existing defects or wounds to gain entry to epithelia, non opportunistic bacteria, especially the epidemic disease-causing ones, gain access to epithelial cells without evidence of predisposing injury. The molecular mechanisms employed by these non opportunistic pathogens to breach the MAM barrier remain unknown. To test the hypothesis that disease-causing non opportunistic bacteria gain access to the epithelium by removal of MAMs, corneal, conjunctival, and tracheobronchial epithelial cells, cultured to differentiate to express the MAMs, MUCs 1, 4, and 16, were exposed to a non encapsulated, non typeable strain of Streptococcus pneumoniae (SP168), which causes epidemic conjunctivitis. The ability of strain SP168 to induce MAM ectodomain release from epithelia was compared to that of other strains of S. pneumoniae, as well as the opportunistic pathogen Staphylococcus aureus. The experiments reported herein demonstrate that the epidemic disease-causing S. pneumoniae species secretes a metalloproteinase, ZmpC, which selectively induces ectodomain shedding of the MAM MUC16. Furthermore, ZmpC-induced removal of MUC16 from the epithelium leads to loss of the glycocalyx barrier function and enhanced internalization of the bacterium. These data suggest that removal of MAMs by bacterial enzymes may be an important virulence mechanism employed by disease-causing non opportunistic bacteria to gain access to epithelial cells to cause infection
Prevalence of subclinical thyroid disorders in type 2 diabetes mellitus
Background: Subclinical thyroid disorders usually do not produce symptoms of thyroid disease until they turn into over thyroid disease. Thyroid disease is more common in people with diabetes mellitus than in the general population and it is important to detect thyroid disorder before its clinical manifestation. Subclinical hypothyroidism (SCH) can produce dyslipidemia, obesity thus resulting increased predisposition to coronary artery disease. Subclinical hyperthyroidism can aggravate hyperglycemia and impair blood sugar control. Objectives: Our objective is to determine the prevalence of subclinical thyroid disorders in patients with type 2 diabetes mellitus (T2DM) and to analyze the clinical and metabolic profile of patients with this dual endocrine disorder. Methods and Results: One hundred consecutive type 2 diabetic patients without clinical manifestations of thyroid disorders were screened for SCH and subclinical hyperthyroidism using serum free T 3 , free T 4 and thyroid stimulating hormone (TSH) levels. Individuals of subclinical thyroid disease were further screened for thyroperoxidase (TPO) antibodies. SCH was detected in 13% of type 2 diabetic patients and none had subclinical hyperthyroidism in our study. SCH was common among females with type 2 diabetes (84.6%). Elevated TPO antibody levels were present in 84.6% SCH patients. Diabetic retinopathy among SCH patients showed significant association with higher serum TSH levels. Left ventricular diastolic dysfunction was present in 30.8% of SCH patients. Conclusion: SCH is common among type 2 diabetic patients, especially in females. It is most commonly secondary to autoimmune thyroid disease. Microvascular complications are commonly observed in this group of patients with dual endocrinal disorder and treating physician should be aware of the impact and should routinely screen SCH to prevent complications
Significant knockdown of MUC1 and MUC16 proteins in both cell lysates and on apical cell surfaces following transfection with vectors expressing shMUC1 or shMUC16 sequences.
<p>(A) Western blots demonstrating that <b>MUC1 protein</b> is lower in both cell lysates (upper left) and on apical cell surfaces (lower left) of cell cultures transfected with shMUC1 containing vectors (shMUC1) compared to the non-transfected control (NT), scrambled shRNA (scr1) controls, as well as with shMUC16 containing vector (shMUC16) or its scrambled shRNA control (scr16). Alleles of MUC1 often differ in size and as they are co-dominantly expressed, two distinct protein sizes are evident on western blots. The graphs to the right of each blot, show densitometric analyses of bands demonstrating that MUC1 protein levels are significantly reduced by 71% in the cell lysates and 60% on apical surfaces relative to NT and scr1 controls and that MUC1 protein levels are not significantly reduced by knockdown of MUC16 (shMUC16) or its scrambled shRNA control (scr16). (B) Similarly, on the left are representative Western blots demonstrating that MUC16 protein levels are lower in cell lysates and biotinylated apical cell surface protein isolates of cells transfected with shMUC16 containing vectors compared to non-transfected (NT), or those transfected with scrambled shRNA for either MUC1 or MUC16 (scr1 and scr16) or shMUC1 containing vectors. The graphs on the right show densitometric analyses of blots indicating that MUC16 protein levels are significantly reduced in cell lysates by 70% and on apical surfaces by 51% in cells transfected with shMUC16 containing vectors in comparison to NT and scr16 controls. For both (A) and (B) protein samples from cell lysates were loaded based on equivalent micrograms of protein, and for cell surface proteins on equivalent cm<sup>2</sup> of cell growth area. Graphic representation of the relative amounts of MUC1 (upper right) and MUC16 (lower right) was derived through densitometric analyses of the blots, cell lysates were normalized to GAPDH, and all data were expressed relative to the non-transfected control (NT). Significant if p<0.01, (**). ns = non-significant, n = 5–10.</p