Publications by authors named "Ashkin A"

Introduction: Salmonella infections usually present as self-limiting gastrointestinal illnesses. Salmonella pneumonia is an uncommon infection that should be considered in immunodeficient individuals originally presenting with enterocolitis. With fewer than 40 reported cases, salmonella pneumonia can rarely lead to empyema (1.

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Objectives: To determine if integrating VDOT into TB therapy demonstrated non-inferiority to direct observation, and if VDOT utilization increased across Florida after the onset of Covid-19.

Methods: A statewide programmatic review was conducted of all patients in Florida who initiated tuberculosis treatment between January 2018 - December 2018 and January 2020 - December 2021, as documented by the Florida Department of Health.

Results: 1361 patients received treatment within the analysis timeframe.

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With its exceeding rarity, there is little research on the quadricuspid aortic valve (QAV) inherently to drive guideline-based management. This leaves physicians without evidence-based guidance on the management of such patients should they come across this finding on imaging or should they care for a symptomatic patient. This article describes the case of an incidentally identified QAV in a patient undergoing treatment for tuberculosis, which seemingly had bicuspid-appearing valve hemodynamics.

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Burkitt lymphoma (BL) is a neoplasm of the lymphoid tissue and one of the most prevalent malignancies worldwide. Classically, these patients present with unregulated B-cell differentiation causing fever, chills, night sweats, and weight loss. Although more common in children, in sporadic Burkitt lymphoma, symptoms often can be present in the abdomen.

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Fibrosing mediastinitis (FM), a rare disorder that is further classified as excessive fibrous tissue that occurs within the mediastinum. Classically, presenting with manifestations dependent on where the fibrous tissue is located. In rare instances, compression of pulmonary vasculature can lead to Pulmonary Hypertension.

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Sarcoid Like Reaction (SLR) is a localized non-caseating epithelioid granulomatous reaction seen secondary to certain immunotherapies and malignancies. Invasive melanoma, while being associated with onset of sarcoidosis, has not shown to directly induce SLR in the literature. We present the case of a 68-year-old male with malignant melanoma, who was found to have SLR prior to starting immunotherapy, which worsened while on pembrolizumab.

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Cavernous malformations (CMs) are abnormal clusters of thin-walled blood vessels located in the central nervous system. An 87-year-old male with a history of heart failure with reduced ejection fraction, coronary artery disease, and atrial fibrillation on rivaroxaban was admitted for acute onset, bilateral lower extremity weakness. He was found to have hemorrhagic transformation of a pre-existing spinal cord cavernous malformation located at the level of T9 of the thoracic column worsened by his use of anticoagulation.

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Background: Reported is a patient found to have miliary TB seeding the lungs and brain with CNS involvement resulting in tuberculous meningitis (TBM). False security in laboratory studies that lack adequate sensitivity resulted in delay of therapy which may have negatively impacted the patient's outcome. This case report aims to emphasize the importance of early initiation of therapy when clinical suspicion remains high despite initially negative diagnostic studies.

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West Nile virus (WNV) is classified as a , belonging to a Japanese encephalitis subgroup often transmitted via mosquitoes. The classic presentation of a WNV infection usually displays high fevers, myalgias, and headache which can progress to neck stiffness, stupor, and coma (Case Rep Infect Dis. 2020;2020:6501658).

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Background: Concern for drug-drug interactions leading to treatment failure and drug-resistant strains have discouraged clinicians from attempting concomitant treatment of hepatitis C virus (HCV) and tuberculosis (TB). Increased metabolism of direct-acting antivirals (DAAs) by rifamycins has hindered concurrent use. Development of an assay for ledipasvir and sofosbuvir (LDV/SOF) serum concentrations for therapeutic drug monitoring (TDM) can ensure adequate therapy.

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Objectives: Energy requirements following moderate or severe pediatric traumatic brain injury (TBI) have not been fully elucidated. Indirect calorimetry (IC) is the gold standard for measuring resting energy expenditure (MREE) in PICU. However, technical complexity limits its use.

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Objective: Subdural hematomas (SDH) account for an estimated 5 to 25% of intracranial hemorrhages. Acute SDH occur secondary to rupture of the bridging veins leading to blood collecting within the dural space. Risk factors associated with SDH expansion are well documented, however, there are no established guidelines regarding blood pressure goals in the management of acute SDH.

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Background: Accurate measurement of energy expenditure is not widely available. Patient and clinical factors associated with energy expenditure have been poorly explored, leading to errors in estimation formulae. The objective of this study was to determine clinical factors associated with measured energy expenditure (MEE), expressed in kcal/kg/d, in critically ill children.

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Design for an optical cw atom laser.

Proc Natl Acad Sci U S A

August 2004

A new type of optical cw atom laser design is proposed that should operate at high intensity and high coherence and possibly record low temperatures. It is based on an "optical-shepherd" technique, in which far-off-resonance blue-detuned swept sheet laser beams are used to make new types of high-density traps, atom waveguides, and other components for achieving very efficient Bose-Einstein condensation and cw atom laser operation. A shepherd-enhanced trap is proposed that should be superior to conventional magneto-optic traps for the initial collection of molasses-cooled atoms.

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We calculate the forces of single-beam gradient radiation pressure laser traps, also called "optical tweezers," on micron-sized dielectric spheres in the ray optics regime. This serves as a simple model system for describing laser trapping and manipulation of living cells and organelles within cells. The gradient and scattering forces are defined for beams of complex shape in the ray-optics limit.

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The techniques of optical trapping and manipulation of neutral particles by lasers provide unique means to control the dynamics of small particles. These new experimental methods have played a revolutionary role in areas of the physical and biological sciences. This paper reviews the early developments in the field leading to the demonstration of cooling and trapping of neutral atoms in atomic physics and to the first use of optical tweezers traps in biology.

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Purpose: Our purpose was to show that fertilization of oocytes can be obtained solely by laser light-mediated manipulation of gametes.

Method: A small channel was drilled into the zona pellucida of bovine oocytes using an ultraviolet (UV)-laser microbeam. Highly diluted cattle sperm were not able to fertilize the laser drilled oocytes.

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A combined UV-laser microbeam and optical-tweezers trap was used to perform laser zona drilling and subzonal insemination in cattle. Using a precisely focused UV-laser microbeam, a small channel of about 10 microns in diameter was drilled into the zona pellucida. With a three-dimensional optical-tweezers trap, a single sperm was caught and transported through the laser-drilled hole directly into the perivitelline space.

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We calculate the forces of single-beam gradient radiation pressure laser traps, also called "optical tweezers," on micron-sized dielectric spheres in the ray optics regime. This serves as a simple model system for describing laser trapping and manipulation of living cells and organelles within cells. The gradient and scattering forces are defined for beams of complex shape in the ray-optics limit.

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The new technique of optical trapping and manipulation of living cells using the forces of radiation pressure from infrared single beam gradient laser traps is reviewed. These traps, also referred to as "optical tweezers," are capable of stably trapping transparent micron and submicron biological particles free of optical damage. Entire cells or organelles within the interior of living cells can be manipulated without damaging the cell wall.

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Organelle transport along microtubules is believed to be mediated by organelle-associated force-generating molecules. Two classes of microtubule-based organelle motors have been identified: kinesin and cytoplasmic dynein. To correlate the mechanochemical basis of force generation with the in vivo behaviour of organelles, it is important to quantify the force needed to propel an organelle along microtubules and to determine the force generated by a single motor molecule.

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The ability of infrared laser traps to apply controlled forces inside of living cells is utilized in a study of the mechanical properties of the cytoplasm of plant cells. It was discovered that infrared traps are capable of plucking out long filaments of cytoplasm inside cells. These filaments exhibit the viscoelastic properties of plastic flow, necking, stress relaxation, and set, thus providing a unique way to probe the local rheological properties of essentially unperturbed living cells.

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Use of optical traps for the manipulation of biological particles was recently proposed, and initial observations of laser trapping of bacteria and viruses with visible argon-laser light were reported. We report here the use of infrared (IR) light to make much improved laser traps with significantly less optical damage to a variety of living cells. Using IR light we have observed the reproduction of Escherichia coli within optical traps at power levels sufficient to give manipulation at velocities up to approximately 500 micron s-1.

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Optical trapping and manipulation of viruses and bacteria by laser radiation pressure were demonstrated with single-beam gradient traps. Individual tobacco mosaic viruses and dense oriented arrays of viruses were trapped in aqueous solution with no apparent damage using approximately 120 milliwatts of argon laser power. Trapping and manipulation of single live motile bacteria and Escherichia coli bacteria were also demonstrated in a high-resolution microscope at powers of a few milliwatts.

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