An exopolysaccharide pathway from a freshwater Sphingomonas isolate.

Bacteria embellish their cell envelopes with a variety of specialized polysaccharides. Biosynthesis pathways for these glycans are complex, and final products vary greatly in their chemical structures, physical properties, and biological activities. This tremendous diversity comes from the ability to arrange complex pools of monosaccharide building blocks into polymers with many possible linkage configurations. Due to the complex chemistry of bacterial glycans, very few biosynthetic pathways have been defined in detail. As part of an initiative to characterize novel polysaccharide biosynthesis enzymes, we isolated a bacterium from Lake Michigan called Sphingomonas sp. LM7 that is proficient in exopolysaccharide (EPS) production. We identified genes that contribute to EPS biosynthesis in LM7 by screening a transposon mutant library for colonies displaying altered colony morphology. A gene cluster was identified that appears to encode a complete wzy/wzx-dependent polysaccharide assembly pathway. Deleting individual genes in this cluster caused a non-mucoid phenotype and a corresponding loss of EPS secretion, confirming the role of this gene cluster in polysaccharide production. We extracted EPS from LM7 cultures and determined that it contains a linear chain of 3- and 4-linked glucose, galactose, and glucuronic acid residues. Finally, we show that the EPS pathway in Sphingomonas sp. LM7 diverges from that of sphingan-family EPSs and adhesive polysaccharides such as the holdfast that are present in other Alphaproteobacteria. Our approach of characterizing complete biosynthetic pathways holds promise for engineering polysaccharides with valuable properties. IMPORTANCE: Bacteria produce complex polysaccharides that serve a range of biological functions. These polymers often have properties that make them attractive for industrial applications, but they remain woefully underutilized. In this work, we studied a novel polysaccharide called promonan that is produced by Sphingomonas sp. LM7, a bacterium we isolated from Lake Michigan. We extracted promonan from LM7 cultures and identified which sugars are present in the polymer. We also identified the genes responsible for polysaccharide production. Comparing the promonan genes to those of other bacteria showed that promonan is distinct from previously characterized polysaccharides. We conclude by discussing how the promonan pathway could be used to produce new polysaccharides through genetic engineering.

Importance of pseudoaneurysms after TAVI - a retrospective analysis of 2063 patients.

Background: Bifemoral arterial access is common in patients undergoing transcatheter aortic valve implantation (TAVI), with a primary treatment access (TAVI access) and a secondary non-TAVI access. Pseudoaneurysm (PSA) is an important complication of femoral arterial puncture. Major vascular complications after TAVI are well described, but little is known about PSA. Patients and methods: A total of 2063 patients underwent transfemoral TAVI between January 2014 and January 2020. Vascular ultrasound of the common femoral artery was assessed before and after TAVI. We compared patient characteristics, periprocedural risk scores, procedural characteristics, and access site bleeding events according to Valve Academic Research Consortium 3 (VARC-3) criteria, length of stay (LOS), and all-cause mortality at one year between patients with (46) and without (2017) PSA. Results: The incidence of PSA after TAVI was 2.2% (46/2063). All PSA were successfully treated with ultrasound-guided manual compression (UGMC) or thrombin injection (UGTI) without complications. Patients with PSA had lower platelet counts (210×1000/µl vs. 234×1000/µl; p<0.05), more heart failure symptoms on admission (91% vs. 25%; p<0.05), were more often treated with (N)OACs for atrial fibrillation (AF; 54% vs. 38%; p <0.05), and were less often treated with aspirin (35% vs. 51%; p<0.03). Multivariate analysis identified secondary access site (odds ratio [OR] 8.11; p<0.001) and (N)OAC therapy (OR 1.31; p = 0.037) as risk factors for PSA development. PSA is associated with VARC-3 type 1-3 access site bleeding and longer LOS (15.2 ± 11.3 d vs. 11.6 ± 8.9 d; p<0.01), but this did not affect one year mortality (17% vs. 14%; p = 0.53). Conclusions: Pseudoaneurysms are an important complication after TAVI and are associated with access site bleeding and prolonged hospital stay. (N)OAC therapy and secondary access are important risk factors. Pseudoaneurysms can be safely and effectively treated with thrombin injection and do not affect one-year mortality.

Adverse reactions after intravascular iodinated contrast media administration and their management.

Endovascular interventions and diagnostic examinations using iodinated contrast media (ICM) are standard of care in current vascular medicine. Although ICM use is generally considered safe, it may be associated with adverse reactions, vary from minor disturbances to rare, but severe life-threatening complications. This position paper of European Society of Vascular Medicine integrates current knowledge and summarizes the key information related to the use of intravascular ICM, serving as recommendation on prevention and management of acute, late, and very late adverse reactions. It should help the health professionals in all fields of vascular medicine to make decisions in daily practice for safe use of contrast media.

Digitization of Follow-Up Care in Orthopedic and Trauma Surgery With Video Consultations: Health Economic Evaluation Study From a Health Provider's Perspective.

BACKGROUND: Recommendations for health care digitization as issued with the Riyadh Declaration led to an uptake in telemedicine to cope with the COVID-19 pandemic. Evaluations based on clinical data are needed to support stakeholders' decision-making on the long-term implementation of digital health. OBJECTIVE: This health economic evaluation aims to provide the first German analysis of the suitability of video consultations in the follow-up care of patients in orthopedic and trauma surgery, investigate the financial impact on hospital operations and personnel costs, and provide a basis for decisions on digitizing outpatient care. METHODS: We conducted a randomized controlled trial that evaluated video consultations versus face-to-face consultations in the follow-up care of patients in orthopedic and trauma surgery at a German university hospital. We recruited 60 patients who had previously been treated conservatively or surgically for various knee or shoulder injuries. A digital health app and a browser-based software were used to conduct video consultations. The suitability of telemedicine was assessed using the Telemedicine Satisfaction Questionnaire and the EQ-5D-5L questionnaire. Economic analyses included average time spent by physician per consultation, associated personnel costs and capacities for additional treatable patients, and the break-even point for video consultation software fees. RESULTS: After 4 withdrawals in each arm, data from a total of 52 patients (telemedicine group: n=26; control group: n=26) were used for our analyses. In the telemedicine group, 77% (20/26) of all patients agreed that telemedicine provided for their health care needs, and 69% (18/26) found telemedicine an acceptable way to receive health care services. In addition, no significant difference was found in the change of patient utility between groups after 3 months (mean 0.02, SD 0.06 vs mean 0.07, SD 0.17; P=.35). Treatment duration was significantly shorter in the intervention group (mean 8.23, SD 4.45 minutes vs mean 10.92, SD 5.58 minutes; P=.02). The use of telemedicine saved 25% (€2.14 [US $2.35]/€8.67 [US $9.53]) in personnel costs and increased the number of treatable patients by 172 annually, assuming 2 hours of video consultations per week. Sensitivity analysis for scaling up video consultations to 10% of the hospital's outpatient cases resulted in personnel cost savings of €73,056 (US $ 80,275.39) for a senior physician. A total of 23 video consultations per month were required to recoup the software fees of telemedicine through reduced personnel costs (break-even point ranging from 12-38 in the sensitivity analysis). CONCLUSIONS: Our study supports stakeholders' decision-making on the long-term implementation of digital health by demonstrating that video consultations in the follow-up care of patients in orthopedic and trauma surgery result in cost savings and productivity gains for clinics with no negative impact on patient utility. TRIAL REGISTRATION: German Clinical Trials Register DRKS00023445; https://drks.de/search/en/trial/DRKS00023445.

(Poly)phenol-related gut metabotypes and human health: an update.

Dietary (poly)phenols have received great interest due to their potential role in the prevention and management of non-communicable diseases. In recent years, a high inter-individual variability in the biological response to (poly)phenols has been demonstrated, which could be related to the high variability in (poly)phenol gut microbial metabolism existing within individuals. An interplay between (poly)phenols and the gut microbiota exists, with (poly)phenols being metabolised by the gut microbiota and their metabolites modulating gut microbiota diversity and composition. A number of (poly)phenol metabolising phenotypes or metabotypes have been proposed, however, potential metabotypes for most (poly)phenols have not been investigated, and the relationship between metabotypes and human health remains ambiguous. This review presents updated knowledge on the reciprocal interaction between (poly)phenols and the gut microbiome, associated gut metabotypes, and subsequent impact on human health.

Rising to the challenge of cardio-renal-metabolic disease in the 21st century: Translating evidence into best clinical practice to prevent and manage atherosclerosis.

Rising rates of obesity-associated cardiometabolic disorders allied to ageing populations are driving increases in cardiovascular morbidity and mortality. These adverse trends present challenges for healthcare systems that are struggling to prevent and manage the burgeoning cardiometabolic nexus of multiple long-term conditions. While potent new medications and non-pharmacological interventions have ushered in a promising new therapeutic era, translating clinical trial data to real-world clinical practice is often suboptimal. Postgraduate training and narrowly focused clinical specialisations reflect the traditional siloed approach to managing cardiovascular-metabolic disease that appears increasingly outmoded in the 21st century. It is our contention that greater inter-disciplinary collaboration allied to increased awareness of the continuum of cardiometabolic disease should enable clinicians to address this global public health threat more effectively. With this aim in mind, we have established an International Cardiometabolic Working Group. It is our hope to stimulate the interest of clinicians and clinical researchers across a range of medical specialties who share the vision of better care for people living with cardiometabolic diseases.

Pectic-AGP is a major form of Arabidopsis AGPs.

As a key component in cell walls of numerous organisms ranging from green algae to higher plants, AGPs play principal roles in many biological processes such as cell-cell adhesion and regulating Ca2+ signaling pathway as a Ca2+-capacitor. Consistently, AGP structures vary from species to species and from tissue to tissue. To understand the functions of AGPs, it is vital to know their structural differences relative to their location in the plant. Thus, AGPs were purified from different Arabidopsis tissues. Analyses of these AGPs demonstrated that the AGPs comprised covalently linked pectin and AGP, referred to as pectic-AGPs. Importantly, these pectic-AGPs were glycosylated with a remarkable variety of polysaccharides including homogalacturonan, rhamnogalacturonan-I, and type II arabinogalactan at different ratios and lengths. This result not only suggests that pectic-AGP is a major form of Arabidopsis AGPs, but also supports AGPs serve as crosslinkers covalently connecting pectins with structures tailored for tissue-specific functions.

Low impact injury resulting in a Schenck type IV classified anterior knee dislocation as well as biceps femoris rupture: A Case Report.

Introduction: Dislocations of the knee joint represent very rare injuries in the literature, accounting for less than 0.02% of all musculoskeletal injuries. Case Report: This report describes a patient suffered a knee joint dislocation of the knee joint caused by a low impact injury following a stumbling trauma during volunteer of a sport competition. Anterior knee joint dislocation with incipient compartment syndrome was clinically prognosed. Vascular and nerve injuries were radiologically examined. Taken together the injury was classified as Schenck type IV CN, and surgical management of the current knowledge was pursued. A satisfying range of motion was examined during surgery next to solid vascular und nerve conditions post-surgery. Conclusion: In case of severe knee joint dislocations, the current standard of a closed reduction with subsequent diagnostic is recommended. Compartment syndrome, nerve, and vascular tears indicate emergency surgery.

Temporary decrease in microvascular tissue saturation after transcatheter aortic valve implantation.

BACKGROUND: Data on the effect of transcatheter aortic valve implantation (TAVI) on peripheral microcirculation are limited. OBJECTIVE: The aim of this study is to evaluate peripheral microvascular tissue saturation (StO2) before and after TAVI in relation to central and peripheral hemodynamics, cardiac and renal function. METHODS: In this single-center prospective study, patients with severe aortic stenosis (sAS) scheduled for TAVI or cardiac catheterization (control) were assessed before and up to five days after the procedure. Cardiac function including cardiac output (CO) was assessed by echocardiography. Brachial (bBP) and central blood pressure (cBP), ankle brachial index (ABI), and parameters of arterial stiffness, including augmentation pressure (AP) and augmentation index adjusted for heart rate (AIx@HR75) were measured to assess hemodynamic changes. StO2 was measured in all extremities using a near-infrared spectroscopy (NIRS) camera. Renal function was measured by creatinine levels. RESULTS: 26 patients underwent TAVI and 11 patients served as control. Cardiac output was significantly increased, whereas hemodynamic parameters and peripheral StO2 were significantly decreased after TAVI. At follow-up, StO2 returned to baseline values. Changes in StO2 were negatively related to creatinine levels. CONCLUSION: Transcatheter aortic valve implantation causes a temporary decrease in microvascular tissue saturation that is associated with renal function.

Ballistic Gels in Experimental Fracture Setting.

Biomechanical tests typically involve bending, compression, or shear stress, while fall tests are less common. The main challenge in performing fall tests is the non-reproducible directionality of bone when tested with soft tissue. Upon removal of the soft tissue, the explanted bone's resistance to impact diminishes. Therefore, ballistic gels can fix specimens in reproducible directions and simulate periosteal soft tissue. However, the use of ballistic gels in biomechanical studies is neither standardized nor widespread. This study aimed to optimize a ballistic gel consistency that mimics the upper thigh muscle in sheep. Our results suggest a standardized and flexible evaluation method by embedding samples in ballistic gel. Compression tests were conducted using cylindrical pieces of gluteal muscle from sheep. Various compositions of agarose and gelatin mixtures were tested to achieve a muscle-like consistency. The muscle-equivalent ballistic gel was found to consist of 29.5% gelatin and 0.35% agarose. Bones remained stable within the ballistic gel setup after freeze-thaw cycles between -20 °C and +20 °C. This method reduces the variability caused by muscle and improves storage quality, allowing for tests to be conducted under consistent conditionsBallistic gels of agarose and gelatin are suitable for bone fracture models. They have muscle-like strength, fix fractures simultaneously, are inexpensive to produce, and can be stored to allow repeated measurements of the same object with changing questions.

Prognostic and predictive value of ultrasound-based estimated ankle brachial pressure index at early follow-up after endovascular revascularization of chronic limb-threatening ischaemia: a prospective, single-centre, service evaluation.

Background: Ankle brachial pressure index can be estimated (eABPI) using cuffless ankle Doppler ultrasound. We evaluated the prognostic value of eABPI measured during pre- and post-procedural ultrasound exams to predict the clinical outcome after endovascular revascularisations. Methods: In this prospective, single-centre, service evaluation, consecutive patients with symptomatic peripheral artery disease undergoing lower limb endovascular revascularisations between July, 26 2018 and January, 13 2022 at Surrey and Sussex Healthcare NHS Trust (Redhill, UK) were analysed. eABPI was determined using the higher acceleration index measured with angle-corrected duplex ultrasound in ankle arteries before and ≤1 month post-procedure. Clinical outcomes (mortality, major amputations, amputation-free survival [AFS], clinically driven target lesion revascularization [cdTLR], major adverse limb events [MALE; cdTLR and major amputation], wound healing) were assessed over 1 year. Findings: Of 246 patients treated, for 219 patients (median 75 [IQR 66-83] years) pre- and post-procedural eABPI (0.50 [0.33-0.59] and 0.90 [0.69-1.0], p < 0.0001) were available, respectively. In n = 199 patients with chronic limb-threatening ischaemia (CLTI) Kaplan-Meier survival analyses showed that higher post-procedural, but not pre-procedural, eABPI was associated with favourable AFS, MALE, cdTLR, and wound healing. This was confirmed in Cox regression analysis and remained significant with adjustment for pre-procedural eABPI, age, sex, co-morbidities, treated levels, wound score, and foot infection. Whereas all clinical outcomes, except for survival, were significantly better at ≥0.7 vs <0.7, wound healing (unadjusted: HR 1.7 (95% CI 1.2-2.6), adjusted: HR 2.1 (95% CI 1.3-3.1), cdTLR, and MALE (unadjusted: HR 0.41 (95% CI 0.18-0.93), adjusted: HR 0.28 (95% CI 0.11-0.74) were significantly improved at ≥0.9 vs <0.9. Interpretation: Post-procedural eABPI can provide valid, clinically important prognostic and predictive information. Our data indicate that revascularisations should target values of at least 0.9 to achieve optimal outcomes. Future studies need to confirm generalisability and cost-effectiveness in a wider context. Funding: European Partnership on Metrology, co-financed from European Union's Horizon Europe Research and Innovation Programme and UK Research and Innovation.

Structure and mechanism of biosynthesis of Streptococcus mutans cell wall polysaccharide.

Streptococcus mutans, the causative agent of human dental caries, expresses a cell wall attached Serotype c- specific Carbohydrate (SCC) that is critical for cell viability. SCC consists of a repeating →3)α-Rha(1→2)α-Rha(1→ polyrhamnose backbone, with glucose (Glc) side-chains and glycerol phosphate (GroP) decorations. This study reveals that SCC has one major and two minor Glc modifications. The major Glc modification, α-Glc, attached to position 2 of 3-rhamnose, is installed by SccN and SccM glycosyltransferases and is the site of the GroP addition. The minor Glc modifications are ß-Glc linked to position 4 of 3-rhamnose installed by SccP and SccQ glycosyltransferases, and α-Glc attached to position 4 of 2-rhamnose installed by SccN working in tandem with an unknown enzyme. Both the major and the minor ß-Glc modifications control bacterial morphology, but only the GroP and major Glc modifications are critical for biofilm formation.

Vaccines and Therapeutics for COVID-19 - How Can Understanding SARS-CoV-2 Glycosylation Lead to Pharmaceutical Advances?

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 160 million people worldwide. Researchers have targeted the SARS-CoV-2 structural proteins to better combat the pandemic. Of the four structural proteins, spike (S), membrane (M), envelope (E) and nucleocapsid (N), the S, M and E proteins are glycosylated whereas the N protein is phosphorylated. The glycosylation of the S protein has been reported previously by multiple research groups, and this knowledge has assisted the pharmaceutical industry in developing vaccines and treatment options. In the United States, there are currently three approved COVID-19 vaccines. All three of these vaccines use the S protein to teach host cells how to react when SARS-CoV-2 particles are present. Treatment options utilizing antivirals and immunosuppressants are being developed in addition to vaccines. Different treatment approaches are needed based on the severity of COVID-19 infection. The therapeutic options currently available are not derived through the direct knowledge on SARS-CoV-2 glycosylation. However, more research on the glycosylation of the structural proteins and how this effects SARS-CoV-2 and host cell binding could lead to new and more effective therapeutics. Herein we outline the current vaccine and therapeutic options against COVID-19 available to the public, as well as those still in development.