3,077 research outputs found
Robotic-Assisted Laparoscopic âSalvageâ Rectopexy for Recurrent Ileoanal J-Pouch Prolapse
Total restorative proctocolectomy with ileal pouch-anal anastomosis (RP/IPAA) has become the standard of care for the surgical treatment of ulcerative colitis. Despite its correlation with an excellent quality of life and favorable long-term outcomes, RP/IPAA has been associated with several complications. Prolapse of the ileoanal pouch is a rare and debilitating complication that should be considered in the differential diagnosis of pouch failure. Limited data exist regarding the prevalence and treatment of pouch prolapse. We present the case of a recurrent J-pouch prolapse treated with a novel minimally invasive âsalvageâ approach involving a robotic-assisted laparoscopic rectopexy with mesh
Learning curve for robotic-assisted laparoscopic colorectal surgery.
BACKGROUND: Robotic-assisted laparoscopic surgery (RALS) is evolving as an important surgical approach in the field of colorectal surgery. We aimed to evaluate the learning curve for RALS procedures involving resections of the rectum and rectosigmoid.
METHODS: A series of 50 consecutive RALS procedures were performed between August 2008 and September 2009. Data were entered into a retrospective database and later abstracted for analysis. The surgical procedures included abdominoperineal resection (APR), anterior rectosigmoidectomy (AR), low anterior resection (LAR), and rectopexy (RP). Demographic data and intraoperative parameters including docking time (DT), surgeon console time (SCT), and total operative time (OT) were analyzed. The learning curve was evaluated using the cumulative sum (CUSUM) method.
RESULTS: The procedures performed for 50 patients (54% male) included 25 AR (50%), 15 LAR (30%), 6 APR (12%), and 4 RP (8%). The mean age of the patients was 54.4 years, the mean BMI was 27.8 kg/m(2), and the median American Society of Anesthesiologists (ASA) classification was 2. The series had a mean DT of 14 min, a mean SCT of 115.1 min, and a mean OT of 246.1 min. The DT and SCT accounted for 6.3% and 46.8% of the OT, respectively. The SCT learning curve was analyzed. The CUSUM(SCT) learning curve was best modeled as a parabola, with equation CUSUM(SCT) in minutes equal to 0.73 Ă case number(2) - 31.54 Ă case number - 107.72 (R = 0.93). The learning curve consisted of three unique phases: phase 1 (the initial 15 cases), phase 2 (the middle 10 cases), and phase 3 (the subsequent cases). Phase 1 represented the initial learning curve, which spanned 15 cases. The phase 2 plateau represented increased competence with the robotic technology. Phase 3 was achieved after 25 cases and represented the mastery phase in which more challenging cases were managed.
CONCLUSIONS: The three phases identified with CUSUM analysis of surgeon console time represented characteristic stages of the learning curve for robotic colorectal procedures. The data suggest that the learning phase was achieved after 15 to 25 cases
Intensive family exposure-based cognitive-behavioral treatment for adolescents with anorexia nervosa
Anorexia nervosa exhibits high comorbidity rates and
shared features with anxiety disorders and obsessive-compulsive disorder.
Anxiety-based etiological models have proposed that fear of eating-related
stimuli is the central mechanism around which avoidance of food and foodrelated
rituals are performed. Building on this approach, exposure-based
interventions have demonstrated promising results. Limited evidence in
adolescents encourages the evaluation of exposure approaches in this
population. Method: The current study presents a preliminary evaluation,
in eight adolescents with anorexia nervosa, of an exposure-based CBT
featuring an intensive format and parental involvement. Results:
signifi cant improvements in physical and psychological outcomes were
observed. Conclusions: this case series provides preliminary support
for the effi cacy of intensive family exposure-based CBT for treating
adolescents with severe anorexia nervosa.PsicologĂ
Asynchronous release sites align with NMDA receptors in mouse hippocampal synapses
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Li, S., Raychaudhuri, S., Lee, S. A., Brockmann, M. M., Wang, J., Kusick, G., Prater, C., Syed, S., Falahati, H., Ramos, R., Bartol, T. M., Hosy, E., & Watanabe, S. Asynchronous release sites align with NMDA receptors in mouse hippocampal synapses. Nature Communications, 12(1), (2021): 677, https://doi.org/10.1038/s41467-021-21004-x.Neurotransmitter is released synchronously and asynchronously following an action potential. Our recent study indicates that the release sites of these two phases are segregated within an active zone, with asynchronous release sites enriched near the center in mouse hippocampal synapses. Here we demonstrate that synchronous and asynchronous release sites are aligned with AMPA receptor and NMDA receptor clusters, respectively. Computational simulations indicate that this spatial and temporal arrangement of release can lead to maximal membrane depolarization through AMPA receptors, alleviating the pore-blocking magnesium leading to greater activation of NMDA receptors. Together, these results suggest that release sites are likely organized to activate NMDA receptors efficiently.e also thank the Marine Biological Laboratory and their Neurobiology course for supporting the initial set of experiments (course supported by National Institutes of Health grant R25NS063307). S.W. and this work were supported by start-up funds from the Johns Hopkins University School of Medicine, Johns Hopkins Discovery funds, and the National Science Foundation (1727260), the National Institutes of Health (1DP2 NS111133-01 and 1R01 NS105810-01A1) awarded to S.W. S.W. is an Alfred P. Sloan fellow, McKnight Foundation Scholar, and Klingenstein and Simons Foundation scholar. G.K. was supported by a grant from the National Institutes of Health to the Biochemistry, Cellular and Molecular Biology Program of the Johns Hopkins University School of Medicine (T32 GM007445) and is a National Science Foundation Graduate Research Fellow (2016217537). E.H. and T.M.B. are supported by CRCNS-NIH-ANR grant AMPAR-T. The EM ICE high-pressure freezer was purchased partly with funds from an equipment grant from the National Institutes of Health (S10RR026445) awarded to Scot C Kuo
Abundance of unknots in various models of polymer loops
A veritable zoo of different knots is seen in the ensemble of looped polymer
chains, whether created computationally or observed in vitro. At short loop
lengths, the spectrum of knots is dominated by the trivial knot (unknot). The
fractional abundance of this topological state in the ensemble of all
conformations of the loop of segments follows a decaying exponential form,
, where marks the crossover from a mostly unknotted
(ie topologically simple) to a mostly knotted (ie topologically complex)
ensemble. In the present work we use computational simulation to look closer
into the variation of for a variety of polymer models. Among models
examined, is smallest (about 240) for the model with all segments of the
same length, it is somewhat larger (305) for Gaussian distributed segments, and
can be very large (up to many thousands) when the segment length distribution
has a fat power law tail.Comment: 13 pages, 6 color figure
Inhibition of Cyclin Dependent Kinase 4/6 Overcomes Primary Resistance to Programmed Cell Death 1 Blockade in Malignant Mesothelioma
BACKGROUND: Despite the profound number of malignant pleural mesothelioma (MPM) patients now treated with programmed cell death 1 (PD-1) blockade, insight into the underpinnings of rational therapeutic strategies to treat resistance to checkpoint immunotherapy remains unrealized. Our objective was to develop a novel therapeutic approach to overcome primary resistance to PD-1 blockade in MPM.
METHODS: We generated a transcriptome signature of resistance to PD-1 blockade in MPM patients treated with nivolumab (4 responders and 4 nonresponders). We used The Cancer Genome Atlas MPM cohort (n = 73) to determine what genomic alterations were associated with the resistance signature. We tested whether regulation of identified molecules could overcome resistance to PD-1 blockade in an immunocompetent mouse malignant mesothelioma model.
RESULTS: Immunogenomic analysis by applying our anti-PD-1 resistance signature to The Cancer Genome Atlas cohort revealed that deletion of cyclin dependent kinase inhibitor 2A (CDKN2A) was highly associated with primary resistance to PD-1 blockade. Under the hypothesis that resistance to PD-1 blockade can be overcome by cyclin dependent kinase 4/6 (CDK4/6) inhibition, we tested whether CDK4/6 inhibitors could overcome resistance to PD-1 blockade in subcutaneous tumors derived from Cdkn2a
CONCLUSIONS: We identified a therapeutic target, CDK4/6, to overcome primary resistance to PD-1 blockade through comprehensive immunogenomic approaches. These data provide a rationale for undertaking clinical trials of CDK4/6 inhibitors in more than 40% of patients with MPM who demonstrate loss of CDKN2A
Super-Hubbard models and applications
We construct XX- and Hubbard- like models based on unitary superalgebras
gl(N|M) generalising Shastry's and Maassarani's approach of the algebraic case.
We introduce the R-matrix of the gl(N|M) XX model and that of the Hubbard model
defined by coupling two independent XX models. In both cases, we show that the
R-matrices satisfy the Yang--Baxter equation, we derive the corresponding local
Hamiltonian in the transfer matrix formalism and we determine the symmetry of
the Hamiltonian. Explicit examples are worked out. In the cases of the gl(1|2)
and gl(2|2) Hubbard models, a perturbative calculation at two loops a la Klein
and Seitz is performed.Comment: 26 page
Excerpts from "Instruments interface standards for interoperable ocean sensor networks"
Peer ReviewedPostprint (published version
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