Publications by authors named "Dworkin B"

Alpha heavy chain disease (αHCD) is a rare variant of the mucosa-associated lymphoid tissue lymphoma characterized by expression of a monotypic truncated immunoglobulin α heavy chain. αHCD frequently involves the gastrointestinal (GI) tract, and its pathogenesis has been linked to clonal B-cell expansion from chronic immune stimulation by infectious agents. We report a rare case of GI αHCD with 5 concomitant pathogens identified on a GI multiplex real-time polymerase chain reaction panel, featured by persistent colonization and refractory giardiasis.

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Background and aims Cannabinoids are increasingly used for medicinal purposes, including neuropathy. Gastroparesis is a neuromuscular disorder and neuropathy plays a large role in its pathogenesis. It is thus reasonable that cannabinoids can serve a beneficial role in the management of gastroparesis.

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Introduction: Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder which leads to multiple hospitalizations and causes significant impairment of quality of life. Cannabis use is common in patients with CVS, and there are limited data on the national trends in the prevalence of its use in the United States.

Methods: We used the National Inpatient Sample (NIS) database from 2005 to 2014 and identified hospitalizations with a primary diagnosis of CVS by utilizing the International Classification of Diseases, 9th revision Clinical Modification (ICD-9 CM) coding system.

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Background: Opioid use disorder (OUD) epidemic has been declared a nationwide public health emergency by the Department of Health and Human Services. There are limited data regarding OUD in patients with gastroparesis. This study aimed to evaluate the impact of OUD on the outcomes in patients hospitalized with gastroparesis and to delineate the trends associated with OUD and gastroparesis using a nationally representative sample.

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Background: Ineffective esophageal motility (IEM) is defined as a distal contractile integral < 450 mmHg/s/cm in at least 50% of ten liquid swallows on high-resolution esophageal manometry (HREM). Whether this latest definition correlates with degree of symptoms has not been studied.

Methods: Patients presenting for HREM prospectively rated their symptoms using the Eckardt score.

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Cytomegalovirus (CMV)-induced pseudotumors, or mass-like lesions in the colon, are a rare entity. We report a case of CMV-related spindle cell pseudotumor in an immunocompetent patient with a left ventricular assist device. This case highlights the importance of considering CMV-induced inflammatory pseudotumor when evaluating tumorous lesions in the colon, as well as the importance of appropriate diagnostic work-up, including proper biopsy technique and meticulous review of the pathology.

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Gastrointestinal (GI) tuberculosis (TB) is rare and can occur in the context of active pulmonary disease or as a primary infection with no pulmonary symptoms. It typically presents with vague abdominal symptoms, making it difficult to discern from alternative disease processes. Although the ileocecal region is the most commonly affected site, tuberculous enteritis can involve any aspect of the GI tract.

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Background: The use of isoflurane sedation for prolonged periods in the critical care environment is increasing. However, isoflurane-mediated neurotoxicity has been widely reported. The goal of the present study was to determine whether long-term exposure to low-dose isoflurane in mechanically ventilated rodents is associated with evidence of neurodegeneration or neuroinflammation.

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Ventilation-induced diaphragm dysfunction (VIDD) is a marked decline in diaphragm function in response to mechanical ventilation, which has negative consequences for individual patients' quality of life and for the health care system, but specific treatment strategies are still lacking. We used an experimental intensive care unit (ICU) model, allowing time-resolved studies of diaphragm structure and function in response to long-term mechanical ventilation and the effects of a pharmacological intervention (the chaperone co-inducer BGP-15). The marked loss of diaphragm muscle fiber function in response to mechanical ventilation was caused by posttranslational modifications (PTMs) of myosin.

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Controlled mechanical ventilation (CMV) plays a key role in triggering the impaired diaphragm muscle function and the concomitant delayed weaning from the respirator in critically ill intensive care unit (ICU) patients. To date, experimental and clinical studies have primarily focused on early effects on the diaphragm by CMV, or at specific time points. To improve our understanding of the mechanisms underlying the impaired diaphragm muscle function in response to mechanical ventilation, we have performed time-resolved analyses between 6 h and 14 days using an experimental rat ICU model allowing detailed studies of the diaphragm in response to long-term CMV.

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The muscle wasting and impaired muscle function in critically ill intensive care unit (ICU) patients delay recovery from the primary disease, and have debilitating consequences that can persist for years after hospital discharge. It is likely that, in addition to pernicious effects of the primary disease, the basic life support procedures of long-term ICU treatment contribute directly to the progressive impairment of muscle function. This study aims at improving our understanding of the mechanisms underlying muscle wasting in ICU patients by using a unique experimental rat ICU model where animals are mechanically ventilated, sedated and pharmacologically paralysed for duration varying between 6 h and 14 days.

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The sensitivity of the baroreflex determines its stability and effectiveness in controlling blood pressure (BP). Sleep and arousal are reported to affect baroreflex sensitivity, but the findings are not consistent across studies. After statistically correcting the effect of sleep on the baselines in chronically neuromuscular-blocked (NMB) rats, we found that sleep affects BP and heart period (HP) baroreflex gain similarly.

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A consistent and prominent feature, observed across many species, including our neuromuscular blocked (NMB) rat preparation, is that obliterating the baroafferent inputs to the brainstem, e.g., by sinoaortic denervation (SAD), significantly increases blood pressure variability (BPV).

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In a long-term neuromuscular blocked (NMB) rat preparation, tetanic stimulation of the aortic depressor nerve (ADN) enhanced the A-fiber evoked responses (ERs) in the cardiovascular region, the nucleus of the solitary tract (dmNTS). The potentiation persisted for at least several hours and may be a mechanism for adaptive adjustment of the gain of the baroreflex, with functional implications for blood pressure regulation. Using a capacitance electrode, we selectively stimulated A-fibers and acquired a stable 10-h "A-fiber only" ER baseline at the dmNTS.

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In a long-term (7-21 days) neuromuscular blocked (NMB) rat preparation, using precise single-pulse aortic depressor nerve (ADN) stimulation and stable chronic evoked response (ER) recordings from the dorsal-medial solitary nucleus (dmNTS), two different response patterns were observed: continuous and discrete. For the continuous pattern, activity began approximately 3 ms after the stimulus and persisted for 45 ms; for the discrete pattern, two complexes were separated by a gap from approximately 17 to 25 ms. The early complex was probably transmitted via A-fibers: it had a low stimulus current threshold and an average conduction velocity (CV) of 0.

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The muscle wasting associated with long-term intensive care unit (ICU) treatment has a negative effect on muscle function resulting in prolonged periods of rehabilitation and a decreased quality of life. To identify mechanisms behind this form of muscle wasting, we have used a rat model designed to mimic the conditions in an ICU. Rats were pharmacologically paralyzed with a postsynaptic blocker of neuromuscular transmission, and mechanically ventilated for one to two weeks, thereby unloading the limb muscles.

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To analyse mechanisms of muscle wasting in intensive care unit patients, we developed an experimental model where rats were pharmacologically paralysed by post-synaptic block of neuromuscular transmission (NMB) and mechanically ventilated for 9+/-2 days. Specific interest was focused on the effects on protein and mRNA expression of sarcomeric proteins, i.e.

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In early studies of humans, baroreflex sensitivity was found to be higher during sleep; however, subsequent observations in several species, including humans, have been at variance with the original reports. Sleep and arousal are behavioral states, and it is difficult to accurately and repeatedly measure baroreflex sensitivity in behaving animals. However, pharmacologically immobilized (neuromuscularly blocked) rats have apparently normal sleep-wakefulness cycles, and baroreflex gain can be measured directly in this preparation.

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To determine the relationship between blood pressure (BP) variability and the open-loop frequency domain transfer function (TF) of the baroreflexes, we measured the pre- and postsinoaortic denervation (SAD) spectra and the effects of periodic and step inputs to the aortic depressor nerve and isolated carotid sinus of central nervous system-intact, neuromuscular-blocked (NMB) rats. Similar to previous results in freely moving rats, SAD greatly increased very low frequency (VLF) (0.01-0.

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To characterize the baroreflex in central nervous system-intact neuromuscular-blocked rats, we measured the vascular and cardiac responses and compared direct stimulation of the aortic depressor nerve (ADN) with a capacitance electrode (differentially activating either A or A + C fibers) to carotid sinus pressure with a micro-balloon (SINUS). One-thousand-two-hundred-ninety-seven open-loop measurements of systolic blood pressure (SBP), heart rate, venous pressure (VBP), and mesenteric (msBF), femoral (fmBF), and skin (skBF) blood flow were completed; the linear range of the effects was determined for each response and stimulus mode. The rats were sinoaortic denervated (SAD).

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Recent research on the role of classical conditioning in homeostatic regulation (Dworkin, 1993; Siegel, Krank & Hinson, 1987) has underscored the potential importance of the work of earlier Eastern-European work on physiological conditioning. The present article is a translation and discussion of a paper on blood glucose conditioning, first published in 1954 by the Russian physiologist M.I.

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Pruritus is a common symptom of chronic cholestatic liver diseases but is considered rare in chronic hepatitis. We observed pruritus to be an unusually common complaint in patients with advanced chronic hepatitis C. We reviewed the records of 175 chronic hepatitis C patients to identify patients with severe, diffuse, unexplained pruritus; 12 consecutive prospective patients undergoing liver biopsy for chronic hepatitis C served as controls.

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To evaluate the frequency, pattern, and severity of liver function test abnormalities in patients with Lyme disease associated with erythema migrans (EM), 115 individuals with no other identifiable cause for liver function test abnormalities who presented with EM between July 1990 and September 1993 were prospectively evaluated. For individuals with abnormal liver function tests, common causes of hepatitis, including hepatitis A, B, and C, were excluded. A local control group was used for comparison.

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