Structure-guided glyco-engineering of ACE2 for improved potency as soluble SARS-CoV-2 decoy receptor

Infection and viral entry of SARS-CoV-2 crucially depends on the binding of its Spike protein to angiotensin converting enzyme 2 (ACE2) presented on host cells. Glycosylation of both proteins is critical for this interaction. Recombinant soluble human ACE2 can neutralize SARS-CoV-2 and is currently undergoing clinical tests for the treatment of COVID-19. We used 3D structural models and molecular dynamics simulations to define the ACE2 N-glycans that critically influence Spike-ACE2 complex formation. Engineering of ACE2 N-glycosylation by site-directed mutagenesis or glycosidase treatment resulted in enhanced binding affinities and improved virus neutralization without notable deleterious effects on the structural stability and catalytic activity of the protein. Importantly, simultaneous removal of all accessible N-glycans from recombinant soluble human ACE2 yields a superior SARS-CoV-2 decoy receptor with promise as effective treatment for COVID-19 patients.

Best practices for design and fabrication of biomicrofluidic devices by resin 3D printing

Stereolithographic (SL) 3D printing, especially digital light processing (DLP) printing, is a promising rapid fabrication method for bio-microfluidic applications such as clinical tests, lab-on-a-chip devices, and sensor integrated devices. The benefits of 3D printing lead many to believe this fabrication method will accelerate the use of bioanalytical microfluidics, but there are major obstacles to overcome to fully utilize this technology. For commercially available printing materials, this includes challenges in producing prints with the print resolution and mechanical stability required for a particular design, along with cytotoxic components within many SL resins and low optical compatibility for imaging experiments. Potential solutions to these problems are scattered throughout the literature and rarely available in head-to-head comparisons. Therefore, we present here principles for navigation of 3D printing techniques and systematic tests to inform resin selection and optimization of the design and fabrication of SL 3D printed bio-microfluidic devices.

A diagnostic tool for people with lumbar instability: a criterion-related validity study

Background Several clinical tests used to identify patients with lumbar instability have reported diagnostic accuracy in separate studies with conflicting results. To augment the diagnostic process, tests that are better able to identify lumbar instability suitable for use in the clinical setting are required. The aim of this study was to identify the probability to diagnose patients with lumbar instability, using x-ray imaging as the reference standard. Methods This study was a cross-sectional, diagnostic validity study. One hundred forty participants with chronic low back pain underwent an x-ray assessment and 14 clinical examinations. Data were analysed using multivariate regression methods to determine which clinical tests were most diagnostic for lumbar instability when they were applied together. Results Eighteen (12.85%) participants had radiological lumbar instability. Three clinical tests i) interspinous gap change during flexion-extension, ii) passive accessory intervertebral movement tests, iii) posterior shear test demonstrated an ability to diagnose lumbar instability of 67% when they were all positive. At this probability threshold, sensitivity, specificity, positive likelihood ratio (+LR), and negative likelihood ratio (−LR) were 5.56, 99.18%, 6.78, and 0.95. Conclusions These 3 clinical tests could be useful in identifying patients with lumbar instability in the general community. These three tests are simple to perform by physical therapists, reliable to use in a clinical setting, and safe for patients. We recommend physical therapists use these three tests to assess patients who are suspected of having lumbar instability, in the absence of an x-ray assessment, to receive appropriate targeted intervention or referral for further investigation. Trial registration Thai Clinial Trial Registry (TCTR 20180820001; 19th August 2018).

More on search for causes of sensitization to tuberculin PPD for mammals in cattle

Despite the large number of papers dealing with the description of proposed methods for bovine tuberculosis diagnosis and mechanisms of non-specific reaction development in diseased and healthy animals, various aspects require further study. Many specialists are still of the view, formulated when studying causes of pseudoallergic reactions, that the agents of actinomycosis, trematode infections etc. can cause sensitization of the animal body to tuberculin PPD for mammals. The possibility of sensitization of cattle body to Аctinomyces bovis tuberculin was studied in 240 animals identified as actinomycosis diseased among 3,473 tested animals. Only 11 (4.6%) of the total number of diseased animals were reactors to tuberculin PPD for mammals. During bacteriological tests of material from animals euthanized for diagnostic purposes (tuberculin reactors and nonreactors with a confirmed postmortem diagnosis of actinomycosis), acid-tolerant nontuberculous mycobacterium (NTM) cultures were isolated. The results of the experiment conducted in 628 cows of a dairy holding confirmed that Actinomyces bovis lacks tuberculin-associated allergenicity: actinomycosis was detected only in one of 96 (15.2%) tuberculin reactors. The conducted clinical tests with high significance level (Р < 0.005) showed that there is no association between allergic reaction to tuberculin PPD for mammals and actinomycosis infection. The obtained results are indicative of imperfections in differential diagnosis, and further studies in this field should significantly contribute to gaining a better insight into non-specific sensitization of cattle body to tuberculin.

Management of Computer Vision Syndrome with Saindhava Jala Seka and Triphala Ghritapana - A Case Study

Computer vision syndrome (CVS) is a symptom complex in which symptoms develop due to long screening time and improper postures while using computers. Ayurveda has mentioned Shushkakshipaka under Sarvagat Netra Roga. The symptoms of CVS and Shushkakshipaka when corelated, it denotes imbalance of Vata and Pitta Dosha. These vitiated Doshas carried by Siras to the eyes. When Doshas accumulated in eye the condition develops, called as Shushkakshipaka. Over use of Internet, Computers, Electronic devices increasing the risk factors about maintaining the normal vision. For the management of the CVS case, the Saindhava Jala Seka and Abhyantara Triphala Ghritapana is chosen from Sushrut Samhita. Triphala Ghrita is beneficial for complete maintenance of physiology of eye. The Guna Karma of Saindhava and Triphala Ghrita are Vata-Pitta Shamaka and both having Chakshushya properties. The main purpose for this study is to find safe and effective treatment without untoward effect in the management of CVS along with respective ergonomics advice. The required clinical tests done to observe the effectiveness of the combination of local and systemic treatment. The dryness in the eyes and associated symptoms can be resolved with the local treatment like Seka. Both the treatment modalities in combination have potential to give local and systemic relief improving the symptoms of CVS.

Prism Adaptation and Optokinetic Stimulation Comparison in the Rehabilitation of Unilateral Spatial Neglect

Prism adaptation (PA) is one of the most effective treatments for the rehabilitation of unilateral spatial neglect. Optokinetic stimulation (OKS) has also been demonstrated to be effective in ameliorating symptoms of neglect. The aim of this study is to compare the effectiveness of these two methods in a group of neglect patients using a crossover design. A group of 13 post-acute brain-damaged patients with unilateral spatial neglect, who had never been rehabilitated, were treated using PA and OKS. Each treatment was applied for 10 sessions, twice a day, to all patients with both treatments in crossed order (i.e., PA followed by OKS or vice versa). Neuropsychological assessments were performed: before the first (T1), at the end of the first/beginning of the second (T2) and at the end of the second training sessions (T3), and two weeks after the end of treatment (T4). Both procedures produced a significant improvement in clinical tests at T2, independent of the type of training. The results suggest that either PA or OKS induces a significant amelioration of neglect in right brain-damaged patients, mainly in the first block of treatment. Since no differences between treatments were found, they could be applied in clinical practice, according to the requirements of the individual patient.

Continuous assessment of sweat lactic acid secretion using microfluidic sweat lactic acid monitoring system

A microfluidic sweat lactic acid (LA) monitoring system for non-invasive and continuous assessment of sweat LA was constructed and tested. Our system transports whole secretions from the skin to an electrochemical LA biosensor using a continuous flow of phosphate buffered saline at the skin’s surface. The LA biosensor was fabricated by modifying screen printed carbon electrodes with osmium wired horseradish peroxidase and lactate oxidase. For continuous monitoring purposes, the microfluidic LA biosensor was connected with a flow cell made of polydimethylsiloxane (PDMS). The sampling device was fabricated by laminating a medical plaster on a PDMS flow-channel. Before the clinical tests, the characteristics of the LA biosensor were evaluated. Sufficient sensitivity (0.4232 nA/µM) and selectivity to LA (> 50fold against glucose, glutamic acid, phenylalanine, ammonia and ethanol) were confirmed. Besides, the medical plaster-based attachment contributed to the reduced leakage between the skin and the sampling device. Under the approval of the ethical committees, LA monitoring of patients with cardiovascular disease at the intensive care unit was carried out. As a result, temporal changes of sweat LA were successfully monitored.