Publications by authors named "Swank D"

Background: Undetected obstructive sleep apnea (OSA) is highly prevalent in patients undergoing bariatric surgery and increases perioperative risks. Screening for OSA using preoperative polygraphy (PG) with subsequent continuous positive airway pressure (CPAP) is costly and time-consuming. Postoperative continuous pulse oximetry (CPOX) is less invasive, and is hypothesized to be a safe and cost-effective alternative.

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Background: To assess the prevalence, incidence, location, and behavior of chronic pre- and postoperative pain in bariatric surgery, and the use of analgesics.

Methods: A cross-sectional e-survey was conducted on 3928 post-bariatric patients and four-time points for pain assessment were evaluated: preoperative, on the ward, day 1 at home postoperatively, and present time (at the time of the e-survey). A numerical rating scale (NRS) was used to assess the level of pain (0 to 10).

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Purpose: Obstructive sleep apnea (OSA) is highly prevalent but mostly undiagnosed in obese patients scheduled for bariatric surgery. To prevent cardiopulmonary complications, many clinics perform preoperative OSA screening. Consequently, adequate adherence to continuous positive airway pressure (CPAP) therapy is essential but challenging.

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Background: Roux-en-Y gastric bypass (RYGB) has proven to be an effective treatment for obesity with excellent long-term results, even though weight regain can occur. A method to improve the results of RYGB and minimize chance of weight regain is banded RYGB. Better sustained weight loss is also related to higher remission of comorbidities.

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A muscle undergoing cyclical contractions requires fast and efficient muscle activation and relaxation to generate high power with relatively low energetic cost. To enhance activation and increase force levels during shortening, some muscle types have evolved stretch activation (SA), a delayed increased in force following rapid muscle lengthening. SA's complementary phenomenon is shortening deactivation (SD), a delayed decrease in force following muscle shortening.

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Background: Although the sleeve gastrectomy (SG) has good short-term results, it comes with a significant number of patients requiring revisional surgery because of insufficient weight loss or functional complications.

Objective: To investigate the effectiveness of the single anastomosis duodenoileal bypass (SADI-S) versus the Roux-en-Y gastric bypass (RYGB) on health outcomes in (morbidly) obese patients who had previously undergone SG, with up to 5 years of follow-up.

Methods: Data from patients who underwent revisional SADI-S or RYGB after SG were retrospectively compared on indication of surgery, weight loss, quality of life, micronutrient deficiencies, and complications.

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Dilated cardiomyopathy (DCM), a life-threatening disease characterized by pathological heart enlargement, can be caused by myosin mutations that reduce contractile function. To better define the mechanistic basis of this disease, we employed the powerful genetic and integrative approaches available in To this end, we generated and analyzed the first fly model of human myosin-induced DCM. The model reproduces the S532P human β-cardiac myosin heavy chain DCM mutation, which is located within an actin-binding region of the motor domain.

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Muscle contraction is a fundamental biological process where molecular interactions between the myosin molecular motor and actin filaments result in contraction of a whole muscle, a process spanning size scales differing in eight orders of magnitude. Since unique behavior is observed at every scale in between these two extremes, to fully understand muscle function it is vital to develop multi-scale models. Based on simulations of classic measurements of muscle heat generation as a function of work, and shortening rate as a function of applied force, we hypothesize that a model based on molecular measurements must be modified to include a weakly-bound interaction between myosin and actin in order to fit measurements at the muscle fiber or whole muscle scales.

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Freeman-Sheldon syndrome (FSS) is characterized by congenital contractures resulting from dominant point mutations in the embryonic isoform of muscle myosin. To investigate its disease mechanism, we used Drosophila models expressing FSS myosin mutations Y583S or T178I in their flight and jump muscles. We isolated these muscles from heterozygous mutant Drosophila and performed skinned fiber mechanics.

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Introduction: Despite the high prevalence of obstructive sleep apnoea (OSA) in obese patients undergoing bariatric surgery, OSA is undiagnosed in the majority of patients and thus untreated. While untreated OSA is associated with an increased risk of preoperative and postoperative complications, no evidence-based guidelines on perioperative care for these patients are available. The aim of the POPCORN study (ost-perative ulse oximetry without OSA sreening vs perioperative continuous positive airway pressure (CPAP) treatment following SA sceeing by polygraphy (PG)) is to evaluate which perioperative strategy is the most cost-effective for obese patients undergoing bariatric surgery without a history of OSA.

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Background: Distal arthrogryposis (DA) is a group of autosomal dominant skeletal muscle diseases characterized by congenital contractures of distal limb joints. The most common cause of DA is a mutation of the embryonic myosin heavy chain gene, MYH3. Human phenotypes of DA are divided into the weakest form-DA1, a moderately severe form-DA2B (Sheldon-Hall Syndrome), and a severe DA disorder-DA2A (Freeman-Sheldon Syndrome).

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Purpose: The clinical diagnosis of an internal herniation (IH) after a Roux-en-Y Gastric Bypass (RYGB) remains difficult; therefore, performing a CT scan is usually part of the diagnostic process. The goal of this study was to assess the incidence of IH in patients with open and closed MD (mesenteric defect) and to study if the ability to diagnose an IH with a CT scan is different between these groups.

Materials And Methods: IH was defined as a visible intestine through the mesenteric defect underneath the jejunojejunostomy and/or in the Petersen's space.

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Article Synopsis
  • Striated muscle contraction is controlled by the movement of troponin-tropomyosin over thin filaments and relies on electrostatic interactions for relaxation.
  • * The M305L mutation in α-cardiac actin affects this regulation by decreasing actin flexibility, which leads to abnormal muscle contraction and relaxation.
  • * This research indicates that maintaining actin's flexibility is crucial for proper muscle function and regulation of force generation.
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The force response of cardiac muscle undergoing a quick stretch is conventionally interpreted to represent stretching of attached myosin crossbridges (phase 1) and detachment of these stretched crossbridges at an exponential rate (phase 2), followed by crossbridges reattaching in increased numbers due to an enhanced activation of the thin filament (phases 3 and 4). We propose that, at least in mammalian cardiac muscle, phase 2 instead represents an enhanced detachment rate of myosin crossbridges due to stretch, phase 3 represents the reattachment of those same crossbridges, and phase 4 is a passive-like viscoelastic response with power-law relaxation. To test this idea, we developed a two-state model of crossbridge attachment and detachment.

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Stretch activation (SA) is a delayed increase in force following a rapid muscle length increase. SA is best known for its role in asynchronous insect flight muscle, where it has replaced calcium's typical role of modulating muscle force levels during a contraction cycle. SA also occurs in mammalian skeletal muscle but has previously been thought to be too low in magnitude, relative to calcium-activated (CA) force, to be a significant contributor to force generation during locomotion.

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Key Points: Hypertrophic cardiomyopathy (HCM) is a genetic disease that causes thickening of the heart's ventricular walls and is a leading cause of sudden cardiac death. HCM is caused by missense mutations in muscle proteins including myosin, but how these mutations alter muscle mechanical performance in largely unknown. We investigated the disease mechanism for HCM myosin mutation R249Q by expressing it in the indirect flight muscle of Drosophila melanogaster and measuring alterations to muscle and flight performance.

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The hyperbolic shape of the muscle force-velocity relationship (FVR) is characteristic of all muscle fiber types. The degree of curvature of the hyperbola varies between muscle fiber types and is thought to be set by force-dependent properties of different myosin isoforms. However, the structural elements in myosin and the mechanism that determines force dependence are unresolved.

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K146N is a dominant mutation in human β-cardiac myosin heavy chain, which causes hypertrophic cardiomyopathy. We examined how muscle responds to this mutation and integratively analyzed the biochemical, physiological and mechanical foundations of the disease. ATPase assays, actin motility, and indirect flight muscle mechanics suggest at least two rate constants of the cross-bridge cycle are altered by the mutation: increased myosin attachment to actin and decreased detachment, yielding prolonged binding.

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Background: Sleeve gastrectomy (SG) has become the most performed bariatric procedure to induce weight loss worldwide. Unfortunately, a significant portion of patients show insufficient weight loss or weight regain after a few years.

Objective: To investigate the effectiveness of the single anastomosis duodenoileal (SADI) bypass versus the Roux-en-Y gastric bypass (RYGB) on health outcomes in morbid obese patients who had undergone SG previously, with up to 2 years of follow-up.

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Muscles have evolved to power a wide variety of movements. A protein component critical to varying power generation is the myosin isoform present in the muscle. However, how functional variation in muscle arises from myosin structure is not well understood.

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We describe a case of polymicrobial bacterial pericarditis with and , caused by pericardial penetration of the tip of the catheter of a laparoscopic adjustable gastric band (LAGB). The patient developed a cardiac tamponade, and subsequently emergency pericardiocentesis was performed. Analysis of earlier CT scans showed that the tip of the catheter had migrated through the liver and through the diaphragm into the pericardium, and was in contact with the myocardium.

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Muscle stretch activation (SA) is critical for optimal cardiac and insect indirect flight muscle (IFM) power generation. The SA mechanism has been investigated for decades with many theories proposed, but none proven. One reason for the slow progress could be that multiple SA mechanisms may have evolved in multiple species or muscle types.

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Individuals with inclusion body myopathy type 3 (IBM3) display congenital joint contractures with early-onset muscle weakness that becomes more severe in adulthood. The disease arises from an autosomal dominant point mutation causing an E706K substitution in myosin heavy chain type IIa. We have previously expressed the corresponding myosin mutation (E701K) in homozygous indirect flight muscles and recapitulated the myofibrillar degeneration and inclusion bodies observed in the human disease.

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Objective: To evaluate the effect of a self-gripping mesh (Progrip) on the incidence of chronic postoperative inguinal pain (CPIP) and recurrence rate after Lichtenstein hernioplasty.

Background: Chronic pain is the most common complication of inguinal hernioplasty. One of the causes may be the use of sutures to secure the mesh.

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