Chemical and morphological characterization and pulping of Casuarina equisetifolia

Bangladesh is very much successful in coastal afforestation programmes, which protects from frequent cyclones. Casuarina equisetifolia has showed a climate resilient and promising species. No study has been done on industrial application of C. equisetifolia in Bangladesh. In this study, C. equisetifolia was characterized in terms of chemical, morphological and anatomical properties. It is characterized with higher α-cellulose, similar hemicelluloses and lignin as compared to other hardwood species grown in Bangladesh. The C. equisetifolia lignin contained mainly of syringyl unit followed by guaiacyl unit. The fiber of C. equisetifolia was shorter in length with very thick cell wall and narrow lumen, consequently the wood density and runkel ratio were very high (2.89). The C. equisetifolia was also fractionated by formic acid (FA) at atmospheric pressure to pulp, dissolved lignin and hemicelluloses. Pulp yield was 50 % with kappa number of 40 at the conditions of 3 h treatment with 90 % FA followed by 2 h peroxyformic acid treatment. But in the kraft process, C. equisetifolia produced pulp yield of 44 % with kappa number 17. Both pulps showed good bleachability. The papermaking properties were in acceptable range. Finally, it can be said that C. equisetifolia is promising species for pulping.

Structural mechanisms for gating and ion selectivity of the human polyamine transporter ATP13A2

Mutations in ATP13A2, also known as PARK9, cause a rare monogenic form of juvenile onset Parkinson's disease named Kufor-Rakeb syndrome and other neurodegenerative diseases. ATP13A2 encodes a neuroprotective P5B P-type ATPase highly enriched in the brain that mediates selective import of spermine ions from lysosomes into the cytosol via an unknown mechanism. Here we present three structures of human ATP13A2 bound to an ATP analogue or to spermine in the presence of phosphomimetics determined by electron cryo-microscopy. ATP13A2 autophosphorylation opens a lysosome luminal gate to reveal a narrow lumen access channel that holds a spermine ion in its entrance. ATP13A2's architecture establishes physical principles underlying selective polyamine transport and anticipates a "pump-channel" intermediate that could function as a counter-cation conduit to facilitate lysosome acidification. Our findings establish a firm foundation to understand ATP13A2 mutations associated with disease and bring us closer to realizing ATP13A2's potential in neuroprotective therapy.

Using A New Endodontic Tooth Model as an Alternative in Clinical Education Course During the Covid-19 Pandemic

Background The COVID-19 pandemic massively impacts endodontic teaching and a dramatically reduced number of patients is registered in clinical courses. This could be countered with suitable training aids. Based on treatment errors made by students in the last five years of endodontic courses at RWTH Aachen University (Germany), a new artificial root canal treatment model (DRSK RCT) was developed. The model was aimed to be radiopaque and to simulate the tactile feel during instrumentation in a realistic manner. Unlike already existing 3D-printed tooth replicas, the RCT has anatomical root canals with a narrow lumen with its width matching an ISO size 6 endodontic file. Methodology 35 fourth-year students and seven dental demonstrators performed endodontic treatments on both the DRSK RCT and extracted teeth. Students and demonstrators answered a questionnaire on a scale ranging from 1 to 7 (poor to high) for different items (part 1). After the first study, changes in the materials and root canal anatomy were applied to the model. Then, the whole study was repeated and evaluated (part 2). Finally, it was evaluated whether the models could replace patient treatment during the Covid-19 pandemic. Results Ratings by students and dental instructors (5.1 ± 0.4 and 5.3 ± 1.5 [mean ± SD], respectively) in the first study increased after modifications of the DRSK RCT (5.5 ± 0.5 and 6.2 ± 0.8, respectively). Radiographs of the models were excellently assessable. The properties of the DRSK RCT were found to be realistic, thus allowing students to perform a satisfactory simulation of root canal treatment and being rated sufficient in substituting patient treatment during COVID-19 pandemic. Conclusion The analysis suggests that the DRSK RCT has the ability to improve endodontic technique and education. Visible root canals enable students to observe the treatment process. All steps of a regular root canal treatment can be simulated. Further studies are needed to investigate the outcome of treating the first patient after practicing on the DRSK RCT.

Beat-By-Beat Cardiomyocyte T-Tubule Deformation Drives Tubular Content Exchange

Rationale: The sarcolemma of cardiomyocytes contains many proteins that are essential for electro-mechanical function in general, and excitation-contraction coupling in particular. The distribution of these proteins is non-uniform between the bulk sarcolemmal surface and membrane invaginations known as transverse tubules (TT). TT form an intricate network of fluid-filled conduits that support electro-mechanical synchronicity within cardiomyocytes. Although continuous with the extracellular space, the narrow lumen and the tortuous structure of TT can form domains of restricted diffusion. As a result of unequal ion fluxes across cell surface and TT membranes, limited diffusion may generate ion gradients within TT, especially deep within the TT network and at high pacing rates. Objective: We postulate that there may be an advective component to TT content exchange, wherein cyclic deformation of TT during diastolic stretch and systolic shortening serves to mix TT luminal content and assists equilibration with bulk extracellular fluid. Methods and Results: Using electron tomography, we explore the 3D nanostructure of TT in rabbit ventricular myocytes, preserved at different stages of the dynamic cycle of cell contraction and relaxation. We show that cellular deformation affects TT shape in a sarcomere length-dependent manner and on a beat-by-beat time-scale. Using fluorescence recovery after photobleaching microscopy, we show that apparent speed of diffusion is affected by the mechanical state of cardiomyocytes, and that cyclic contractile activity of cardiomyocytes accelerates TT diffusion dynamics. Conclusions: Our data confirm the existence of an advective component to TT content exchange. This points towards a novel mechanism of cardiac autoregulation, whereby the previously implied increased propensity for TT luminal concentration imbalances at high electrical stimulation rates would be countered by elevated advection-assisted diffusion at high mechanical beating rates. The relevance of this mechanism in health and during pathological remodelling (e.g. cardiac hypertrophy or failure) forms an exciting target for further research.

The treatment of sialolithiasis by sialolithotripsy

Aim. To study the effectiveness of treatment of sialolithiasis by sialolithotripsy. Methods. Between 2015 and 2018, extracorporeal shockwave lithotripsy of salivary stones of 39 patients was performed in the Nasreddin Tusi Memorial Clinic. The stone was located in the submandibular gland and its duct for 33 patients and the parotid salivary glands and its duct for 6 patients. The average age of patients was 503.38 (between 22 and 77). Results. Stone fragmentation as a result of sialolithotripsy was achieved in 36 (92.7%) of 39 examined patients (p=0.031). In 3 patients the stone was completely fragmented, but due to the narrow lumen of the main duct, it did not move away. In 3 patients with calculus size more than 2 cm, the stone was not fragmented. According to our results, the necessary effect was achieved in 85% of cases and was unachieved in only 15% of cases. Conclusion. Given the complexity of the surgical treatment in patients with salivary stone and potential postoperative complications, especially with the stone localization within the parotid gland, we concluded that extracorporeal shockwave lithotripsy is a promising alternative treatment for patients with salivary stone.

Evaluating the Effects of Cerebrospinal Fluid Protein Content on the Performance of Differential Pressure Valves and Antisiphon Devices Using a Novel Benchtop Shunting Model

BACKGROUND Hydrocephalus is managed by surgically implanting flow-diversion technologies such as differential pressure valves and antisiphoning devices; however, such hardware is prone to failure. Extensive research has tested them in flow-controlled settings using saline or de-aerated water, yet little has been done to validate their performance in a setting recreating physiologically relevant parameters, including intracranial pressures, cerebrospinal fluid (CSF) protein content, and body position. OBJECTIVE To more accurately chart the episodic drainage characteristics of flow-diversion technology. A gravity-driven benchtop model of flow was designed and tested continuously during weeks-long trials. METHODS Using a hydrostatic pressure gradient as the sole driving force, interval flow rates of 6 valves were examined in parallel with various fluids. Daily trials in the upright and supine positions were run with fluid output collected from distal catheters placed at alternating heights for extended intervals. RESULTS Significant variability in flow rates was observed, both within specific individual valves across different trials and among multiple valves of the same type. These intervalve and intravalve variabilities were greatest during supine trials and with increased protein. None of the valves showed evidence of overt obstruction during 30 d of exposure to CSF containing 5 g/L protein. CONCLUSION Day-to-day variability of ball-in-cone differential pressure shunt valves may increase overdrainage risk. Narrow-lumen high-resistance flow control devices as tested here under similar conditions appear to achieve more consistent flow rates, suggesting their use may be advantageous, and did not demonstrate any blockage or trend of decreasing flow over the 3 wk of chronic use.

Endoscopic submucosal dissection: an update on tools and accessories

Endoscopic submucosal dissection (ESD) is a minimally invasive therapeutic procedure to remove larger polyps or early non-metastatic lesions. It has long been used in Asia, but is now fast growing in popularity in the West. There are multiple challenges faced by ESD practitioners. While the practice of ESD in gastric lesions is relatively well established, the oesophagus with its narrow lumen and challenging workspace, and the colon with its tortuous course and folds are more challenging frontiers. The nature of performing a procedure endoscopically means that conventional methods offer no mechanism for providing counter-traction while performing dissection, impeding visibility and increasing the rate of complications. There are a multitude of tools available to those performing ESD for the different stages of the procedure. This article reviews the accessories currently used in regular ESD practice including the knives used to cut and dissect lesions, the cap and hood devices used to improve visibility and safety, injection fluids to lift the submucosal plane, haemostatic devices, generators, and finally, emerging traction apparatus. There is some evidence behind the use of these tools, however, ESD remains the domain of a small number of practitioners and the practice relies heavily on expert experience. Evolution of the ESD toolbox will make the procedure more accessible to more endoscopists, which in turn will drive the development of a more substantial evidence base to evaluate efficacy and safety of the multitude of tools.

Anatomy, Histology, and Ultrastructure of Salivary Glands of the Burrower Bug, Scaptocoris castanea (Hemiptera: Cydnidae)

The burrower bug Scaptocoris castanea Perty, 1830 (Hemiptera: Cydnidae) is an agricultural pest feeding on roots of several crops. The histology and ultrastructure of the salivary glands of S. castanea were described. The salivary system has a pair of principal salivary glands and a pair of accessory salivary glands. The principal salivary gland is bilobed with anterior and posterior lobes joined by a hilus where an excretory duct occurs. The accessory salivary gland is tubular with a narrow lumen that opens into the hilus near the excretory duct, suggesting that its secretion is stored in the lumen of the principal gland. The cytoplasm of the secretory cells is rich in the rough endoplasmic reticulum, secretory vesicles with different electron densities and mitochondria. At the base of the accessory gland epithelium, there were scattered cells that do not reach the gland lumen, with the cytoplasm rich in the rough endoplasmic reticulum, indicating a role in protein production. Data show that principal and accessory salivary glands of S. castanea produce proteinaceous saliva. This is the first morphological description of the S. castanea salivary system that is similar to other Hemiptera Pentatomomorpha, but with occurrence of basal cells in the accessory salivary gland.

Curative Medical Treatment for Acute Appendicitis without Surgical Appendectomy (Jaber Maneuver)

Clinical and Pathological evaluation Acute abdomen with a mixture of modern radiographic images, diagnostic laboratory investigations and clinical observation such as (McBurney’s triangle manifestations with rebound tenderness) [1]. All these signs suggest firmly acute appendicitis with mucosal viral or bacterial infection within the narrow lumen of appendix leading to luminal obstruction, this leads to increase the mucosal secretions, and inflammatory exudates, which increase the intraluminal pressure, obstructed lymphatic drainage. Edema and mucosal ulceration develop with bacterial transudation to the submucosa. Resolution may occur at this point either spontaneously or in response to antibiotics.

Histomorphometrical Study on Regional Variation in Distribution of Sweat Glands in Buffalo Skin

The study was conducted on skin of 24 buffaloes collected from slaughter house. The skin tissues were collected from dorsal, lateral, and ventral parts of head, neck, thorax, abdomen, and tail regions and fixed in 10% neutral buffered formalin. The tissues were processed for paraffin blocks preparation by acetone benzene schedule. The paraffin sections of 5-6 μm were cut with rotary microtome and stained with hematoxylin and eosin. The sweat glands in buffaloes were of saccular and simple coiled tubular type. Most of the sweat glands were associated with hair follicles and consisted of a coiled secretory portion (body) and a straight duct. The secretory portion was made up of glandular tubules, myoepithelium, and basement membrane. The duct portion had a narrow lumen and was lined by simple cuboidal epithelium. The glandular epithelium was simple squamous, simple cuboidal, or low columnar type depending upon their stage of secretary activity. Two types of sweat glands were observed, i.e., apocrine and merocrine. Large number of blood vessels and nerve fibers were observed in the vicinity of the sweat glands. In head, neck, and tail regions the maximum number of sweat glands/mm2 was observed in dorsal side which did not vary significantly (p<0.05) from lateral and ventral side. In abdomen region the number of sweat glands/mm2 was maximum on lateral region which varied significantly from ventral region (p<0.05). Overall, the maximum number of sweat glands/mm2 was in head region followed by abdomen, thorax, neck, and tail but without any significant (p<0.05) difference. Maximum sweat gland diameter was found in abdomen region followed by thorax, head, neck, and tail region.