Thin Muscle Research Articles

Outcomes of ADM-Assisted Implant-based Breast Reconstructions According to Division Types of the Pectoralis Major Muscle.

In implant-based breast reconstruction (IBR), several surgical techniques are based on the implant insertion planes. Ideal location for breast implants has become a popular topic in IBRs because each technique has advantages and disadvantages. Herein, we report the outcomes of three different division types of the pectoralis muscle and suggest an algorithm for selecting the division types. Charts of patients who underwent IBRs between October 2017 and December 2020 were retrospectively reviewed. The patients were classified into three groups (prepectoral, high subpectoral, and subpectoral) according to the division types of the pectoralis muscle. Aesthetic outcomes were assessed in terms of animation deformity, rippling deformity, and visibility of the upper implant border. Total 104 cases were included. 25, 38, and 41 were in the prepectoral, high-subpectoral, subpectoral IBR groups, respectively. Animation deformities frequently appeared in the subpectoral group. Nipple displacement was most prominent in the subpectoral group. Skin rippling at rest was mostly detected in the prepectoral group, whereas ripping during contraction was commonly observed in the subpectoral group. Visibility of upper border was more prominent in the prepectoral group than the other groups. We propose an algorithm for selecting the division types of the pectoralis muscle. If the pectoralis muscle is thick, prepectoral plane is most preferred to avoid the animation deformity. In cases with thin pectoralis muscle, thickness of the mastectomy flap is considered next. If it is thicker than 1cm, prepectoral plane is better than the subpectoral plane; otherwise, high-subpectoral plane is preferable for better aesthetic outcomes. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Protein kinase C epsilon contributes to chronic mechanoreflex sensitization in rats with heart failure.

We investigated second-messenger signalling components linked to the stimulation of Gq protein-coupled receptors (e.g. thromboxane A2 and bradykinin B2 receptors) on the sensory endings of thin fibre muscle afferents in the chronic mechanoreflex sensitization in rats with myocardial infarction-induced heart failure with reduced ejection fraction (HF-rEF). We hypothesized that injection of either the inositol 1,4,5-trisphosphate (IP3) receptor antagonist xestospongin C (5µg) or the PKCε translocation inhibitor PKCe141 (45µg) into the arterial supply of the hindlimb would reduce the increase in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) evoked during 30s of 1Hz dynamic hindlimb muscle stretch in decerebrate, unanaesthetized HF-rEF rats but not sham-operated controls (SHAM). Ejection fraction was significantly reduced in HF-rEF (45 (19)%) compared to SHAM (80 (9)%; P<0.001) rats. In HF-rEF rats (n=3M/2F), IP3 receptor blockade had no effect on the peak ΔRSNA (pre: 99 (74)%; post: 133 (79)%; P=0.974) or peak ΔMAP response to stretch (peak ΔMAP: pre: 32 (14) mmHg; post: 36 (21) mmHg; P=0.719). Conversely, in another group of HF-rEF rats (n=4M/3F), the PKCε translocation inhibitor reduced the peak ΔRSNA (pre: 110 (77)%; post: 62 (58)%; P=0.029) and peak ΔMAP response to stretch (pre: 30 (20) mmHg; post: 17 (16) mmHg; P=0.048). In SHAM counterparts, neither drug affected the mechanoreflex responses. Our findings highlight PKCε, but not IP3 receptors, as a significant second-messenger in the chronic mechanoreflex sensitization in HF-rEF which may play a crucial role in the exaggerated sympathetic response to exercise in this patient population. KEY POINTS: Skeletal muscle contraction results in an exaggerated reflex increase in sympathetic nerve activity in heart failure patients with reduced ejection fraction (HF-rEF) compared to healthy individuals, contributing to increased cardiovascular risk and impaired tolerance for mild exercise. The exaggerated reflex sympathetic responses in HF-rEF may be attributed to a chronic sensitization of mechanically sensitive thin fibre muscle afferents mediated, at least in part, by stimulation of Gq protein-coupled thromboxane A2 and bradykinin B2 receptors on muscle afferent sensory endings. The specific Gq protein-linked signalling mechanisms that produce the chronic mechanoreflex sensitization in HF-rEF have not been investigated but may involve inositol 1,4,5-trisphosphate (IP3) receptors and/or protein kinase C epsilon (PKCε). Here we demonstrate that PKCε, but not IP3 receptors, within the sensory endings of thin fibre muscle afferents plays a role in the sensitization of mechanically sensitive thin fibre muscle afferents in rats with HF-rEF.

FHOD-1 and profilin protect sarcomeres against contraction-induced deformation in C. elegans.

Formin HOmology Domain 2-containing (FHOD) proteins are a subfamily of actin-organizing formins important for striated muscle development in many animals. We showed previously that absence of the sole FHOD protein, FHOD-1, from Caenorhabditis elegans results in thin body wall muscles with misshapen dense bodies that serve as sarcomere Z-lines. We demonstrate here that mutations predicted to specifically disrupt actin polymerization by FHOD-1 similarly disrupt muscle development, and that FHOD-1 cooperates with profilin PFN-3 for dense body morphogenesis, and with profilins PFN-2 and PFN-3 to promote body wall muscle growth. We further demonstrate that dense bodies in worms lacking FHOD-1 or PFN-2/PFN-3 are less stable than in wild type animals, having a higher proportion of dynamic protein, and becoming distorted by prolonged muscle contraction. We also observe accumulation of actin and actin depolymerization factor/cofilin homolog UNC-60B in body wall muscle of these mutants. Such accumulations may indicate targeted disassembly of thin filaments dislodged from unstable dense bodies, possibly accounting for the abnormally slow growth and reduced body wall muscle strength in fhod-1 mutants. Overall, these results implicate FHOD protein-mediated actin assembly in forming stable sarcomere Z-lines, and identify profilin as a new contributor to FHOD activity in striated muscle development.

Impact of wall thickness on tissue cooling effect of cryoballoon ablation: Investigation using an experimental heart model

Abstract Background Understanding of the tissue cooling properties of cryoballoon ablation during pulmonary vein isolation is lacking. Purpose To delineate the depth of the tissue cooling effect during cryoballoon freezing at the pulmonary venous ostium. Methods A left atrial-pulmonary vein model, produced by a 3-dimensional printer using CT data from a patient, was constructed so that porcine thigh muscles of various thicknesses could be fixed and thermocouples could be fixed at locations corresponding to the epicardial side of the pulmonary vein ostium. The model was placed in a 37-degree water bath with a pulmonary vein water flow at a rate that mimicked biological blood flow, and the cryoballoon was advanced into the left superior vein until the vein was completely occluded. Cryofreezing was performed 5 times each for a porcine thigh muscle of 2-, 4-, and 6-mm thickness, and epicardial tissue cooling was monitored as assessed by the mean temperature of 12 evenly distributed thermocouples covering the roof region of the left superior vein. Results Epicardial tissue cooling effects were more in the order of 2-mm, 4-mm, and 6-mm thickness (Figure) with a mean temperature of -41.4 ± 4.2 for 2 mm, -33.0 ± 4.0 for 4 mm, and 8.0 ± 8.7 °C for 6 mm at 180 sec (p for trend &amp;lt; 0.0001). In addition, tissue temperature drops were steeper in thin muscle (maximum temperature drop per 5 s: 5.2 ± 0.9, 3.9 ± 0.7, 1.3 ± 0.7 °C, p for trend &amp;lt; 0.0001). Conclusion The cooling effect is weaker in the deeper layers during cryobaloon freezing, and longer freezing duration would be recommended in case of thick myocardium.

Impact of wall thickness on the tissue cooling effect of cryoballoon ablation.

Understanding of the tissue cooling properties of cryoballoon ablation during pulmonary vein (PV) isolation is lacking. The purpose of this study was to delineate the depth of the tissue cooling effect during cryoballoon freezing at the pulmonary venous ostium. A left atrial-PV model was constructed using a three-dimensional printer with data from a patient to which porcine thigh muscle of various thicknesses could be affixed. The model was placed in a 37°C water tank with a PV water flow at a rate that mimicked biological blood flow. Cryofreezing at the PV ostium was performed five times each for sliced porcine thigh muscle of 2, 4, and 6 mm thickness, and sliced muscle cooling on the side opposite the balloon was monitored. The cooling effect was assessed using the average temperature of 12 evenly distributed thermocouples covering the roof region of the left superior PV. Tissue cooling effects were in the order of the 2, 4, and 6 mm thicknesses, with an average temperature of -41.4 ± 4.2°C for 2 mm, -33.0 ± 4.0°C for 4 mm, and 8.0 ± 8.7°C for 6 mm at 180 s (P for trend <0.0001). In addition, tissue temperature drops were steeper in thin muscle (maximum temperature drop per 5 s: 5.2 ± 0.9°C, 3.9 ± 0.7°C, and 1.3 ± 0.7°C, P for trend <0.0001). The cooling effect of cryoballoon freezing is weaker in the deeper layers. Cryoballoon ablation should be performed with consideration to myocardial thickness.

Pathogenic TNNI1 variants disrupt sarcomere contractility resulting in hypo- and hypercontractile muscle disease.

Troponin I (TnI) regulates thin filament activation and muscle contraction. Two isoforms, TnI-fast (TNNI2) and TnI-slow (TNNI1), are predominantly expressed in fast- and slow-twitch myofibers, respectively. TNNI2 variants are a rare cause of arthrogryposis, whereas TNNI1 variants have not been conclusively established to cause skeletal myopathy. We identified recessive loss-of-function TNNI1 variants as well as dominant gain-of-function TNNI1 variants as a cause of muscle disease, each with distinct physiological consequences and disease mechanisms. We identified three families with biallelic TNNI1 variants (F1: p.R14H/c.190-9G>A, F2 and F3: homozygous p.R14C), resulting in loss of function, manifesting with early-onset progressive muscle weakness and rod formation on histology. We also identified two families with a dominantly acting heterozygous TNNI1 variant (F4: p.R174Q and F5: p.K176del), resulting in gain of function, manifesting with muscle cramping, myalgias, and rod formation in F5. In zebrafish, TnI proteins with either of the missense variants (p.R14H; p.R174Q) incorporated into thin filaments. Molecular dynamics simulations suggested that the loss-of-function p.R14H variant decouples TnI from TnC, which was supported by functional studies showing a reduced force response of sarcomeres to submaximal [Ca2+] in patient myofibers. This contractile deficit could be reversed by a slow skeletal muscle troponin activator. In contrast, patient myofibers with the gain-of-function p.R174Q variant showed an increased force to submaximal [Ca2+], which was reversed by the small-molecule drug mavacamten. Our findings demonstrated that TNNI1 variants can cause muscle disease with variant-specific pathomechanisms, manifesting as either a hypo- or a hypercontractile phenotype, suggesting rational therapeutic strategies for each mechanism.

Retrospective analysis and comparison of total internal disability preservation technique and standardized reconstruction technique

To investigate the efficacy and clinical results of total internal protection technique in anterior cruciate ligament reconstruction. A total of 56 patients undergoing anterior cruciate ligament reconstruction treated from January 2018 to December 2019 were selected. According to the different surgical methods, they were divided into total internal reconstruction group and standard bone tunnel group. There were 21 patients in the total internal reconstruction group, including 15 males and 6 females, aged from 20 to 48 with an average of (35.6±6.7) years old, and 35 patients in the standard tibial tunnel group, including 26 males and 9 females, aged 22 to 51 years old with an average of (33.7±9.6) years old. Preoperative examination of Lachman test was positive, magnetic resonance indicated anterior cruciate ligament rupture. There were no significant differences between the two groups in age, sex, body mass index, time from injury to ACL reconstruction, combined meniscus injury and operation method, operation time, ligament diameter, ligament length and other general information. Postoperative evaluation included operation duration, length and diameter of transplanted tendon after braid. International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner score and perioperative complications 2 years after surgery. Both groups were followed up, ranging from 24 to 30 months with an average of (26.9±3.4) months. Postoperative incision healing was good, and no failure or joint infection occurred at the last follow-up. There was no statistically significant difference between the two groups in IKDC score, Lysholm score and Tegner score before, 1 year and 2 years after surgery. However, IKDC score, Lysholm score and Tegner score at 1 year and 2 years after surgery. The same postoperative function and stability of knee joint can be obtained by both the residual whole technique and the standardized reconstruction technique. In the residual whole group, only the semitendinosus muscle is taken, and the femoral thin muscle is retained, with greater tibial bone mass preserved, which is safe and effective in clinical practice.

Complementary information on the biology of Bactrian camels (Camelus bactrianus) in the Mangistau region of Kazakhstan

The morphometric body parameters of male and female Bactrian camels, Kazakh Bactrian, were studied. Compared to camels of other breeds, the Kazakh Bactrian turned out to be one of the largest camels, having up to 750 kg for males and 690 kg for females, as well as powerful musculature and thick fur. Sexual dimorphism in body size and weight of males and females has been shown. The height at the withers of males was higher than in females by about 3.2 %, oblique length of the trunk by 4.5 %, chest girth by 1.3 %, and tibia girth by 6.6 % higher than in females. The greatest difference was in the live weight of the animals - 23,4 %. A histological study of one of the important internal organs - kidneys - was carried out, which allow camels to adapt to the conditions of waterless deserts. As a result of histological study of the kidneys of Kazakh Bactrians, the following characteristics of camel kidneys were established: the kidney capsule is rather thick (470±12 μm) and is made up of two layers: a layer of collagen fibres (400 μm) and thin (70 μm) inner smooth muscle cells. The relative thickness of the capsule and the presence of the smooth muscle cell layer within it appear to be related to the kidney’s ability to hold high intrarenal pressure while producing highly concentrated urine. The second feature of the Bactrian kidney was that the medullary layer was much thicker than the cortical layer. Their ratio was 1:4. The thick cerebral layer in camels provides relatively long renal tubules and loops of Henle, which are essential for the excretion of concentrated urine.

Histological anatomical levels of penile shaft. A histochemical evaluation of 15 cases

Abstract Introduction/Objective Penile carcinomas (PeCa) arising in the skin of the shaft are rare. Staging systems for PeCa are based on tumor invasion of anatomical levels designed for tumors arising in the glans and foreskin but not for those primary of the shaft. There is scant information about anatomical levels in the shaft. The objective of this study was to evaluate and describe anatomical levels of the shaft with emphasis of the fascias, using histochemical stains. Methods/Case Report Sections of penile mid shaft from 15 penectomies with PeCa from 2000-2015 were evaluated. H&amp;E, trichromic and orcein stains were performed to evaluate and describe anatomical levels of the shaft. Results (if a Case Study enter NA) Skin: Epidermis: 7-15 cell thick, thin keratin, granulosis, basal pigmentation. Papillary dermis: Loose connective tissue, capillaries, nerve fibers pilo-sebaceous structures. Absence of elastic fibers. Reticular dermis. prominent elastic fibers layer parallel to epidermis merging with dartos. Dartos (superficial fascia): Poorly delineated, merging with reticular layer with no separating space, composed of thin smooth muscle bundles. Deep fascia (Busck's fascia): All tissues between dartos and tunica albuginea. Fibro-elastic, encases vessels, nerves and fibro adipose tissues. Closely attached to the albuginea.Tunica albuginea: Dense mostly fibrous tissue with few elastic fibers encasing corpora cavernosa. Corpus cavernosum: Thick-walled inter-anastomosed vessels. Smaller nutritional vessels, nerves and adipose tissue. No elastic fibers present. Conclusion There are 5 distinct anatomical layers in the shaft. Reticular dermis and dartos should be considered as one layer given the poor delineation between them. This knowledge is necessary for staging and prognosis of the rare PeCa arising in the shaft.

Esophageal anatomy and physiology vary across spastic and non-spastic phenotypes of disorders of esophagogastric junction outflow.

Pathophysiologic mechanisms of disorders of esophagogastric junction (EGJ) outflow are poorly understood. We aimed to compare anatomic and physiologic characteristics among patients with disorders of EGJ outflow and normal motility. We retrospectively evaluated adult patients with achalasia types 1, 2, 3, EGJ outflow obstruction (EGJOO) or normal motility on high-resolution manometry who underwent endoscopic ultrasound (EUS) from January 2019 to August 2022. Thickened circular muscle was defined as ≥1.6 mm. Characteristics from barium esophagram (BE) and functional lumen imaging probe (FLIP) were additionally assessed. Of 71 patients (mean age 56.2 years; 49% male), there were 8 (11%) normal motility, 58 (82%) had achalasia (5 (7%) type 1, 32 (45%) classic type 2, 21 (30%) type 3 [including 12 type 2 with FEPs]), and 7 (7%) had EGJOO. A significantly greater proportion of type 3 achalasia had thickened distal circular muscle (76.2%) versus normal motility (0%; p < 0.001) or type 2 achalasia (25%; p < 0.001). Type 1 achalasia had significantly wider mean maximum esophageal diameter on BE (57.8 mm) compared to type 2 achalasia (32.8 mm), type 3 achalasia (23.4 mm), EGJOO (15.9 mm), and normal motility (13.5 mm). 100% type 3 achalasia versus 0% type 1 achalasia/normal motility had tertiary contractions on BE. Mean EGJ distensibility index on FLIP was lower for type 3 achalasia (1.2 mmHg/mm2 ) and EGJOO (1.2 mmHg/mm2 ) versus type 2 (2.3 mmHg/mm2 ) and type 1 achalasia (2.9 mmHg/mm2 ). Our findings suggest distinct pathologic pathways may exist: type 3 achalasia and EGJOO may represent a spastic outflow phenotype consisting of a thickened, spastic circular muscle, which is distinct from type 1 and 2 achalasia consisting of a thin caliber circular muscle layer with more prominent esophageal dilation.

Active-Bending Six-Bar Tensegrity Modular Robot Driven by Thin Artificial Muscles

Active-Bending Six-Bar Tensegrity Modular Robot Driven by Thin Artificial Muscles

Knowing Human Personality Based on Phisis Constitutional Typology According to Kretschmer and Sheldon’s Understanding

Typology is knowledge that seeks to classify or group humans into certain types on the basis of certain factors, such as physical characteristics, psychics, dominant influences, cultural values, and so on. According to KBBI, typology is the science of character about the human part in groups according to their respective traits. Personality psychology is one of the branches of psychology that explains the human personality or all the behaviors and characteristics of individual habits that accumulate in him and it is used to react and can also adapt to all stimuli, both inside and outside of behavior and habits is a functional unity especially for a person. Kretschmer developed a human typology based on the physical constitution and psychic constitution based on the physical constitution, human types are further divided into 4 types, while based on the psychic constitution, humans are divided into two types. Kretschmer's theory is one of the great works of the early 20th century. He was a German mental illness expert. Kretschmer built his topology on the basis of physical and psychological structures. Physical structure is divided into 4, namely the type of picnic, asthenic athletic and dysplastic. Personality is also defined and explained by different psychologists in various ways. William Herbert still has his own ideas about personality. He provides the theory that body type can be related to the personality of the person. more muscular body, more active and aggressive, thin or thin people with thin muscles are usually characterized as quiet or fragile.

Fascial plane mapping for superficial tumor resection in dogs. Part III: Hindlimb and pelvis.

To categorize the fascial planes and the intersections of these fascial planes in the hindlimb of the dog to facilitate preoperative planning for superficial cancers. Qualitative anatomical study. Four male and five female mixed breed dogs, weighing ~15-35 kg. Skin and subcutaneous fat were removed, and fascial planes were explored to determine borders and quality. Fascia was categorized as type I (discrete sheets), type II (adhered to thin muscles), type III (adhered to thick muscles), or type IV (associated with periosteum). Digital modification of specimen photographs was performed to map tissues. Differences in dogs were noted due to either size or sex but were sufficiently minor to allow mapping. Fasciae of the hindlimb were predominantly type II or III, with type I fascia primarily at the lateral gluteal region, fascia lata, and lateral crus. Type IV fascia was seen at the iliac wing, ischium, patella, tibial tuberosity, medial tibia, distal crus, and pes. Fascia for surgical use was thin or absent at the ischiorectal fossa, femoral triangle, extensor mechanism, medial and distal crus, and pes. Intersections and tissues at the ventral perineum may also pose challenges for maintenance of a deep margin. Fascial types and integrity of the hindlimb varied with location, with the perineum, cranial stifle, and distal limb presenting the greatest challenges. These images may be used to guide both therapeutic decision-making and intraoperative excision of superficial tumors of the hindlimb and pelvis.

A CASE REPORT ON THE BILATERAL PSOAS MINOR MUSCLES WITH CLINICAL SIGNIFICANCE

The Psoas Minor is a thin paired muscle of the posterior abdominopelvic region, placed in front of the Psoas major.The psoas minor muscle is considered inconstant and is often absent, only being present in about 40% of human specimens studied.The psoas minor muscle originates from the vertical fascicles inserted on the last thoracic and first lumbar vertebrae. From there, it passes down onto the medial border of the psoas major and is inserted to the innominate line and the iliopectineal eminence. Additionally, it attaches to and stretches the deep surface of the iliac fascia and occasionally its lowermost fibers reach the inguinal ligament.

Optogenetic Calcium Ion Influx in Myoblasts and Myotubes by Near-Infrared Light Using Upconversion Nanoparticles.

Bioactuators made of cultured skeletal muscle cells are generally driven by electrical or visible light stimuli. Among these, the technology to control skeletal muscle consisting of myoblasts genetically engineered to express photoreceptor proteins with visible light is very promising, as there is no risk of cell contamination by electrodes, and the skeletal muscle bioactuator can be operated remotely. However, due to the low biopermeability of visible light, it can only be applied to thin skeletal muscle films, making it difficult to realize high-power bioactuators consisting of thick skeletal muscle. To solve this problem, it is desirable to realize thick skeletal muscle bioactuators that can be driven by near-infrared (NIR) light, to which living tissue is highly permeable. In this study, as a promising first step, upconversion nanoparticles (UCNPs) capable of converting NIR light into blue light were bound to C2C12 myoblasts expressing the photoreceptor protein channelrhodopsin-2 (ChR2), and the myoblasts calcium ion (Ca2+) influx was remotely manipulated by NIR light exposure. UCNP-bound myoblasts and UCNP-bound differentiated myotubes were exposed to NIR light, and the intracellular Ca2+ concentrations were measured and compared to myoblasts exposed to blue light. Exposure of the UCNP-bound cells to NIR light was found to be more efficient than exposure to blue light in terms of stimulating Ca2+ influx.

Sonoanatomy of the platysmal bands: What causes the platysmal band?

The platysmal band is created by the platysma muscle, a thin superficial muscle that covers the entire neck and the lower part of the face. The platysmal band appears at the anterior and posterior borders of the muscle. To date, no definite pathophysiology has been established. Here, we observed a lack of knowledge of the anatomy of the platysma muscle using ultrasonography in this study. We conducted a descriptive, prospective study observing the platysmal band in resting and contraction states to reveal muscle changes. Twenty-four participants (aged 23-57years) with anterior and posterior neck bands underwent ultrasonography in resting and contracted states. Ten cadavers were studied aged 67-85years to measure the thickness of the platysma muscle at 12 points: horizontally (medial, middle, lateral) and vertically (inferior mandibular margin, hyoid bone, cricoid cartilage, superior margin of clavicle). The anterior and posterior borders of the platysma muscle were thicker than the middle of the platysma muscle when in a contracted state, and the muscle also had a convex shape when contracted. The thickness of the platysma muscle was not significantly different over 12 points in the resting state. During contraction, the platysma muscles contracted in the medial and lateral margins of the muscle, which was more significant in the posterior bands. The anterior and posterior platysmal bands are related to muscle thickness during contraction. These observations support the change in platysmal band treatment only at the anterior and posterior border of the muscle.

Creating and Transferring an Innervated, Vascularized Muscle Flap Made from an Elastic, Cellularized Tissue Construct Developed In Situ.

Reanimating facial structures following paralysis and muscle loss is a surgical objective that would benefit from improved options for harvesting appropriately sized muscle flaps. The objective of this study is to apply electrohydrodynamic processing to generate a cellularized, elastic, biocomposite scaffold that could develop and mature as muscle in a prepared donor site in vivo, and then be transferred as a thin muscle flap with a vascular and neural pedicle. First, an effective extracellular matrix (ECM) gel type is selected for the biocomposite scaffold from three types of ECM combined with poly(ester urethane)urea microfibers and evaluated in rat abdominal wall defects. Next, two types of precursor cells (muscle-derived and adipose-derived) are compared in constructs placed in rat hind limb defects for muscle regeneration capacity. Finally, with a construct made from dermal ECM and muscle-derived stem cells, protoflaps are implanted in one hindlimb for development and then microsurgically transferred as a free flap to the contralateral limb where stimulated muscle function is confirmed. This construct generation and in vivo incubation procedure may allow the generation of small-scale muscle flaps appropriate for transfer to the face, offering a new strategy for facial reanimation.

Endoscopic Resection Techniques for Duodenal and Ampullary Adenomas.

Duodenal polyps have a reported incidence of 0.3% to 4.6%. Sporadic, nonampullary duodenal adenomas (SNDAs) comprise less than 10% of all duodenal polyps, and ampullary adenomas are even less common. Nonetheless, the incidence continues to rise because of widespread endoscopy use. Duodenal polyps with villous features or those that are larger than 10mm may raise concern for malignancy and require removal. We demonstrate endoscopic resection of SNDAs and ampullary adenomas using some of our preferred techniques. The duodenum has several components that can make EMR of duodenal polyps technically challenging. Not only does the duodenum have a thin muscle layer, but it is also highly mobile and vascular, which may explain higher rates of perforation and bleeding of duodenal EMR reported in the literature compared with colon EMR. A standard adult gastroscope with a distal cap is commonly used for duodenal EMRs. Based on the location, however, side-viewing duodenoscopes or pediatric colonoscopes may be used. To prepare for EMR, a submucosal injection is performed for an adequate lift. The polyp is then resected via stiff monofilament snares and subsequently closed with hemostatic clips if feasible. The ampullectomy technique differs slightly from duodenal EMRs and carries the additional risk of pancreatitis. Submucosal injection in the ampulla may not lift well; thus, its utility is debatable. Biliary sphincterotomy should be performed, and based on endoscopist preference, the pancreatic duct (PD) guidewire can be left during resection to maintain access. After resection, a PD stent is placed to minimize pancreatitis risk. The video shows the aforementioned duodenal EMR techniques. Two clips of ampullectomy are also shown in the video. A few common techniques used to perform duodenal EMR and ampullectomy are highlighted in the video. It is important to understand and manage adverse events associated with these procedures and to have established surveillance plans.

Sudden cardiac death of a 16-year-old boy with Wolff-Parkinson-White syndrome and hypertrophic cardiomyopathy

AbstractIn Europe, 350,000 people die suddenly and unexpectedly every year. The majority of sudden deaths are caused by cardiac alterations and known as sudden cardiac death (SCD). The interpretation of medicolegal findings is especially difficult in those SCDs where there is no morphological correlate and no antemortem electrocardiograms or relevant medical history are available. The Wolff-Parkinson-White (WPW) syndrome, in which an accessory electrical conduction pathway exists between the atrium and the ventricle in addition to the physiological conduction system, is mostly a benign disease of the heart, which may lead to cardiac arrhythmia. A 16-year-old boy with a known history of WPW syndrome since the second year of life had consumed alcohol before death and was found sitting on the toilet fully dressed. The autopsy performed on the deceased 3 days postmortem showed a marked mass increase of the heart with left ventricular concentric hypertrophy and macroscopic signs of cardiomyopathy. In the microscopic examination, the right and left ventricles and the atria were found to have a regular structure with normal vessels. Hematoxylin-eosin (HE) and elastica-van-Gieson (EvG) staining disclosed a thin accessory muscle bridge connecting the left atrium with the left ventricle as a possible morphological correlate of a fatal cardiac arrhythmia.

Sex-dependent attenuating effects of capsaicin administration on the mechanoreflex in healthy rats.

Stimulation of mechanically sensitive channels on the sensory endings of group III and IV thin fiber muscle afferents activates the mechanoreflex, which contributes to reflex increases in sympathetic nerve activity (SNA) and blood pressure during exercise. Accumulating evidence suggests that activation of the nonselective cation channel transient receptor potential vanilloid-1 (TRPV1) on the sensory endings of thin fiber afferents with capsaicin may attenuate mechanosensation. However, no study has investigated the effect of capsaicin on the mechanoreflex. We tested the hypothesis that in male and female decerebrate, unanesthetized rats, the injection of capsaicin (0.05 µg) into the arterial supply of the hindlimb reduces the pressor and renal SNA (RSNA) response to 30 s of 1 Hz rhythmic hindlimb muscle stretch (a model of isolated mechanoreflex activation). In male rats (n = 8), capsaicin injection significantly reduced the integrated blood pressure (blood pressure index or BPI: pre, 363 ± 78; post, 211 ± 88 mmHg·s; P = 0.023) and RSNA [∫ΔRSNA; pre, 687 ± 206; post, 216 ± 80 arbitrary units (au), P = 0.049] response to hindlimb muscle stretch. In female rats (n = 8), capsaicin injection had no significant effect on the pressor (BPI; pre: 277 ± 67; post: 207 ± 77 mmHg·s; P = 0.343) or RSNA (∫ΔRSNA: pre, 697 ± 123; post, 440 ± 183 au; P = 0.307) response to hindlimb muscle stretch. The data suggest that the injection of capsaicin into the hindlimb arterial supply to stimulate TRPV1 on the sensory endings of thin fiber muscle afferents attenuates the mechanoreflex in healthy male, but not female, rats. The findings may carry important implications for chronic conditions in which an exaggerated mechanoreflex contributes to aberrant sympathoexcitation during exercise.NEW & NOTEWORTHY Recent evidence in isolated sensory neurons indicates that capsaicin-induced stimulation of TRPV1 attenuates mechanosensitivity. Here we demonstrate for the first time that capsaicin exposure/administration reduces the reflex pressor and renal sympathetic nerve response to mechanoreflex activation in male rats, but not female rats, in vivo. Our data may carry important clinical implications for chronic diseases which have been linked to an exaggerated mechanoreflex, at least in males.