794 research outputs found
747-6 Myocardial Blood Flow in Aortic Regurgitation: Comparison of Global and Regional Blood Flow to Regional Wall Stresses
The impact of regional wall stress (WS) abnormalities on regional coronary flow (CBF) in aortic regurgitation (AR) is not known. However, the existence of such a relation is of potential importance since it might account in part for LV dysfunction and myocardial fibrosis seen in AR, and could suggest therapeutic strategies. We have previously developed and validated a method for calculating regional WS in the radial, circumferential and meridional directions from mid wall (MW) to apex (AP) and endocardium (ENDO) to epicardium (EPI) using a 4000 element model of the LV To define the relation of regional WS and CSF in AR, we applied our LV model in 5 normal (NL) and 4 AR rabbits in which regional CBF was measured using fluorescent microspheres. CBF and radial WS were as follows:CBF (ml/min/gm)Radial WS (×103dynes/cm2)MWAPMWAPNLEPI2.491.308329*ENDO2.090.74133133*AREPI1.821.82*8638*ENDO1.410.77*133133**=p<0.001 (EPI vs ENDO for CSF, EPI to ENDO gradient in AR vs NL for radial WS)Thus, in AR, transmural CBF distribution varies significantly at the apex, while this tendency is less marked and less consistent in NL. No discernable transmural variation was apparent elsewhere in either group. These differences paralleled inversely the transmural variations in radial WS in AR vs NL. In contrast, meridional WS and circumferential WS were uniformly and significantly higher in AR than NL at apex and base (all p < 0.001), a pattern which bore no relation to regional CSF pattern. Thus, regional radial WS influences regional transmural CBF pattern in AR. The importance of this relation to regional LV function and regional myocardial fibrosis in AR now must be assessed
Embedding structure matters: Comparing methods to adapt multilingual vocabularies to new languages
Pre-trained multilingual language models underpin a large portion of modern
NLP tools outside of English. A strong baseline for specializing these models
for specific languages is Language-Adaptive Pre-Training (LAPT). However,
retaining a large cross-lingual vocabulary and embedding matrix comes at
considerable excess computational cost during adaptation. In this study, we
propose several simple techniques to replace a cross-lingual vocabulary with a
compact, language-specific one. Namely, we address strategies for
re-initializing the token embedding matrix after vocabulary specialization. We
then provide a systematic experimental comparison of our techniques, in
addition to the recently-proposed Focus method. We demonstrate that: 1)
Embedding-replacement techniques in the monolingual transfer literature are
inadequate for adapting multilingual models. 2) Replacing cross-lingual
vocabularies with smaller specialized ones provides an efficient method to
improve performance in low-resource languages. 3) Simple embedding
re-initialization techniques based on script-wise sub-distributions rival
techniques such as Focus, which rely on similarity scores obtained from an
auxiliary model
Applying TLC (a Targeted Learning Community) to Transform Teaching and Learning in Science
This article describes the development of a Targeted Learning Community (TLC) that supports first-year science students enrolled in a General Chemistry course. Drawing on student feedback and knowledge and expertise in their respective disciplines, four faculty members from two colleges at Kennesaw State University came together to develop a learning community that would prevent early attrition in the science majors and increase student metacognition. In this paper, the design of the TLC is presented, and the effect it had on faculty vitality is discussed.
Ruth A. Goldfine is Chair of the Department of First-Year and Transition Studies at Kennesaw State University in Kennesaw, GA.
Hillary H. Steiner (Assistant Professor of Educational Psychology) and Stephanie M. Foote (Associate Professor of Education and Director of the Master of Science in First Year Studies) are also members of the Department of First-Year and Transition Studies at Kennesaw State University.
Michelle L. Dean is an Assistant Professor of Chemistry at Kennesaw State University
Glucagon-like peptide-1 (GLP-1) receptors are not overexpressed in pancreatic islets from patients with severe hyperinsulinaemic hypoglycaemia following gastric bypass
Aims/hypothesis: Glucagon-like peptide-1 (GLP-1) receptors are highly overexpressed in benign insulinomas, permitting in vivo tumour visualisation with GLP-1 receptor scanning. The present study sought to evaluate the GLP-1 receptor status in vitro in other pancreatic disorders leading to hyperinsulinaemic hypoglycaemia, specifically after gastric bypass surgery. Methods: Fresh frozen pancreatic tissue samples (n = 7) from six gastric bypass surgery patients suffering from hyperinsulinaemic hypoglycaemia were evaluated for GLP-1 receptor content using in vitro receptor autoradiography, and compared with normal pancreas and with pancreatic insulinoma tissues. Results: GLP-1 receptor analysis of the pancreatic tissues, which histopathologically were compatible with nesidioblastosis and originated from post-bypass hypoglycaemic patients, revealed a mean density value of GLP-1 receptors in the islets of 1,483 ± 183dpm/mg tissue. Pharmacological characterisation indicated the presence of specific GLP-1 receptors. The density of islet GLP-1 receptor in post-gastric bypass patients did not differ from that of normal pancreas (1,563 ± 104dpm/mg tissue, n = 10). Receptor density in pancreatic acini was low in post-bypass and control conditions. In contrast, benign insulinomas showed a high density of GLP-1 receptors, with a mean value of 8,302 ± 1,073dpm/mg tissue (n = 6). Conclusions/interpretation: In contrast to insulinoma, hyperinsulinaemic hypoglycaemia after gastric bypass surgery is not accompanied by overexpression of GLP-1 receptor in individual islets. Thus, patients with post-gastric bypass hyperinsulinaemic hypoglycaemia are not candidates for GLP-1 receptor imaging in vivo using radiolabelled exendin. These GLP-1 receptor data support the notion that the islet pathobiology of post-gastric bypass hypoglycaemia is distinctly different from that of benign insulinoma
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Nobody Wants to Be Narcan\u27d: A Pilot Qualitative Analysis of Drug Users\u27 Perspectives on Naloxone
INTRODUCTION: Bystander naloxone distribution is an important component of public health initiatives to decrease opioid-related deaths. While there is evidence supporting naloxone distribution programs, the effects of increasing naloxone availability on the behavior of people who use drugs have not been adequately delineated. In this study we sought to 1) evaluate whether individuals\u27 drug use patterns have changed due to naloxone availability; and 2) explore individuals\u27 knowledge of, access to, experiences with, and perceptions of naloxone.
METHODS: We conducted a pilot study of adults presenting to the emergency department whose medical history included non-medical opioid use. Semi-structured interviews were conducted with participants and thematic analysis was used to code and analyze interview transcripts.
RESULTS: Ten participants completed the study. All were aware of naloxone by brand name (Narcan) and had been trained in its use, and all but one had either currently or previously possessed a kit. Barriers to naloxone administration included fear of legal repercussions, not having it available, and a desire to avoid interrupting another user\u27s high. Of the eight participants who reported being revived with naloxone at least once during their lifetime, all described experiencing a noxious physical response and expressed a desire to avoid receiving it again. Furthermore, participants did not report increasing their use of opioids when naloxone was available.
CONCLUSIONS: Participants were accepting of and knowledgeable about naloxone, and were willing to administer naloxone to save a life. Participants tended to use opioids more cautiously when naloxone was present due to fears of experiencing precipitated withdrawal. This study provides preliminary evidence countering the unsubstantiated narrative that increased naloxone availability begets more high-risk opioid use and further supports increasing naloxone access
Posttranslational incorporation of contractile proteins into myofibrils in a cell-free system.
The impact of salsalate treatment on serum levels of advanced glycation end products in type 2 diabetes.
OBJECTIVE Salsalate is a nonacetylated salicylate that lowers glucose levels in people with type 2 diabetes (T2D). Here we examined whether salsalate also lowered serum-protein-bound levels of early and advanced glycation end products (AGEs) that have been implicated in diabetic vascular complications. RESEARCH DESIGN AND METHODS Participants were from the Targeting Inflammation Using Salsalate for Type 2 Diabetes (TINSAL-T2D) study, which examined the impact of salsalate treatment on hemoglobin A1c (HbA1c) and a wide variety of other parameters. One hundred eighteen participants received salsalate, 3.5 g/day for 48 weeks, and 109 received placebo. Early glycation product levels (HbA1c and fructoselysine [measured as furosine]) and AGE levels (glyoxal and methylglyoxal hydroimidazolones [G-(1)H, MG-(1)H], carboxymethyllysine [CML], carboxyethyllysine [CEL], pentosidine) were measured in patient serum samples. RESULTS Forty-eight weeks of salsalate treatment lowered levels of HbA1c and serum furosine (P \u3c 0.001) and CML compared with placebo. The AGEs CEL and G-(1)H and MG-(1)H levels were unchanged, whereas pentosidine levels increased more than twofold (P \u3c 0.001). Among salsalate users, increases in adiponectin levels were associated with lower HbA1c levels during follow-up (P \u3c 0.001). Changes in renal and inflammation factor levels were not associated with changes in levels of early or late glycation factors. Pentosidine level changes were unrelated to changes in levels of renal function, inflammation, or cytokines. CONCLUSIONS Salsalate therapy was associated with a reduction in early but not late glycation end products. There was a paradoxical increase in serum pentosidine levels suggestive of an increase in oxidative stress or decreased clearance of pentosidine precursor
Nuclear factor κB-inducing kinase activation as a mechanism of pancreatic β cell failure in obesity
The nuclear factor κB (NF-κB) pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic β cell dysfunction in the metabolic syndrome. Whereas canonical NF-κB signaling is well studied, there is little information on the divergent noncanonical NF-κB pathway in the context of pancreatic islet dysfunction. Here, we demonstrate that pharmacological activation of the noncanonical NF-κB-inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. We identify NIK as a critical negative regulator of β cell function, as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of noncanonical NF-κB components p100 to p52, and accumulation of RelB. TNF and receptor activator of NF-κB ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive β cell-intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the noncanonical NF-κB transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to β cell failure. These studies reveal that NIK contributes a central mechanism for β cell failure in diet-induced obesity
High-throughput mediation analysis of human proteome and metabolome identifies mediators of post-bariatric surgical diabetes control
To improve the power of mediation in high-throughput studies, here we introduce High-throughput mediation analysis (Hitman), which accounts for direction of mediation and applies empirical Bayesian linear modeling. We apply Hitman in a retrospective, exploratory analysis of the SLIMM-T2D clinical trial in which participants with type 2 diabetes were randomized to Roux-en-Y gastric bypass (RYGB) or nonsurgical diabetes/weight management, and fasting plasma proteome and metabolome were assayed up to 3 years. RYGB caused greater improvement in HbA1c, which was mediated by growth hormone receptor (GHR). GHR’s mediation is more significant than clinical mediators, including BMI. GHR decreases at 3 months postoperatively alongside increased insulin-like growth factor binding proteins IGFBP1/BP2; plasma GH increased at 1 year. Experimental validation indicates (1) hepatic GHR expression decreases in post-bariatric rats; (2) GHR knockdown in primary hepatocytes decreases gluconeogenic gene expression and glucose production. Thus, RYGB may induce resistance to diabetogenic effects of GH signaling
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