Publications by authors named "Touqir Zahra"

Acute appendicitis is one of the most common abdominal surgical emergencies. A laparoscopic or open appendectomy has traditionally been the gold standard. Antibiotic therapy has recently been found to be noninferior.

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Crohn's disease is an inflammatory bowel disease that has a bimodal distribution, occurring most frequently between ages 15 to 30 years and 40 to 60 years. It presents with a relapsing and remitting course. The most common area involved is the terminal ileum and right colon and the inflammation oftentimes leads to non-caseating granulomas and ulcerations in both the superficial mucosa and deeper layers.

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Esophageal cancer is typically identified as squamous cell carcinoma or adenocarcinoma. There are multiple risk factors that may contribute to esophageal squamous cell carcinoma including smoking, alcohol consumption, and the human papillomavirus. Lesions may appear ulcerated, friable, and circumferential and may obstruct the esophagus.

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The electrocardiographic pattern of early repolarization (ER) is relatively common in the general population. In patients presenting to the emergency room with chest pain, it can be particularly challenging to distinguish ER from life-threatening subtle ST-segment elevation myocardial infarction (STEMI). A 37-year-old male presented to the emergency department with sudden-onset, severe, non-radiating, central chest pain.

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Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that is thoroughly studied and known to have a strong genetic component. It affects the mucosa and submucosa of the colon and rectum, causing diffuse friability and superficial erosions leading to bleeding. Common presenting symptoms include diarrhea that is often bloody or purulent and abdominal pain or cramping.

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Intestinal fibrosis is a rare complication of chronic inflammation resulting from various etiologies, including surgery, abdominal radiation, and inflammatory bowel disease. Consequences of intestinal fibrosis include intestinal dysmotility, malabsorption, and obstruction. Patients with Lynch syndrome are predisposed to developing intestinal adenocarcinoma including in the small intestines which typically require intra-abdominal procedures that expose them to fibrogenic triggers.

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Adenoid cystic carcinoma (ACC) is a rare epithelial tumor that is found in the salivary glands. It is typically slow-growing and follows an indolent course. While it can hematogenously spread to the lungs, distant metastases are rarely reported.

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Inflammation plays an important role in the pathophysiology of atherosclerotic disease. We have previously shown that the targeted photosensitizer chlorin (e(6)) conjugated with maleylated albumin (MA-ce6) is taken up by macrophages via the scavenger receptor with high selectivity. In a rabbit model of inflamed plaque in New Zealand white rabbits via balloon injury of the aorto-iliac arteries and high cholesterol diet we showed that the targeted conjugate showed specificity towards plaques compared to free ce6.

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We have previously shown that a conjugate (MA-ce6) between maleylated serum albumin and the photosensitizer chlorin(e6) (ce6) is targeted in vitro to macrophages via class A scavenger receptors. We now report on the ability of this conjugate to localize in macrophage-rich atherosclerotic plaques in vivo. Both the conjugate and the free photosensitizer ce6 are studied after injection into New Zealand White rabbits that are rendered atherosclerotic by a combination of aortic endothelial injury and cholesterol feeding into normal rabbits.

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The increasing occurrence of multi-antibiotic resistant microbes has led to the search for alternative methods of killing pathogens and treating infections. Photodynamic therapy (PDT) uses the combination of non-toxic dyes and harmless visible light to produce reactive oxygen species that can kill mammalian and microbial cells. Although the photodynamic inactivation of bacteria has been known for over a hundred years, its use to treat infections has not been much developed.

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The emergence of antibiotic resistance among pathogenic bacteria has led to efforts to find alternative antimicrobial therapeutics to which bacteria will not be easily able to develop resistance. One of these may be the combination of nontoxic dyes (photosensitizers [PS]) and visible light, known as photodynamic therapy, and we have reported its use to treat localized infections in animal models. While it is known that gram-positive species are generally susceptible to photodynamic inactivation (PDI), the factors that govern variation in degrees of killing are unknown.

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The worldwide rise in antibiotic resistance necessitates the development of novel antimicrobial strategies. Although many workers have used photodynamic therapy (PDT) to kill bacteria in vitro, the use of this approach has seldom been reported in vivo in animal models of infection. We have previously described the first use of PDT to treat excisional wound infections by Gram-(-) bacteria in living mice.

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We report on the use of optical techniques to monitor and treat Pseudomonas aeruginosa wound infections in mice. Bioluminescent bacteria transduced with a plasmid containing a bacterial lux gene operon allow the infection in excisional mouse wounds to be imaged by use of a sensitive charge-coupled device camera. Photodynamic therapy (PDT) targeted bacteria, by use of a polycationic photosensitizer conjugate, which is designed to penetrate the gram-negative cell wall and was topically applied to the wound and was followed by red-light illumination.

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