Effect of Salts on Laccase-Catalyzed Polymerization of Lignosulfonate.

Enzymatic polymerization of lignosulfonate (LS) has a high potential for various applications ranging from coatings to adhesives. Here, the effect of different ions in low concentrations on enzymatic polymerization of LS was investigated, including salt solutions consisting of mono- and dicarboxylic acids, sulfate, phosphate and chloride with sodium as counter ion. LS polymerization was followed by viscometry and size exclusion (SEC) chromatography. Interestingly, there was only a small effect of ions on the activity of the laccase on standard substrate ABTS, while the effect on polymerization of LS was substantially different. The presence of acetate led to a 39 % higher degree of polymerization (DP) for LS. Small angle X-ray scattering (SAXS) revealed that the structure of the enzyme was largely unaffected by the ions, while the determination of the zeta potential showed that those ions conveying higher negative surface charges onto LS particles showed lower DPs, than those not affecting the surface charge. Further, electron paramagnetic resonance (EPR) spectroscopy showed 5-times higher intensity in phenoxyl radicals for the monovalent ions compared to the divalent ones. It was concluded that the DPs of LS could be tuned in the presence of certain ions, by facilitating the interaction between the laccase substrate-binding site and the LS molecules.

A standardized educational program to improve peripheral vascular access outcomes in the emergency department: A quasi-experimental pre-post trial.

OBJECTIVE: Difficult intravenous access (DIVA) patients are known to have disproportionately poorer vascular access outcomes. The impact of education and training on vascular access outcomes in this vulnerable population is unclear. We aim to demonstrate the success of a program (Operation (O) STICK) on improving vascular access outcomes in DIVA patients. METHODS: This was a quasi-experimental pre-post interventional study conducted at a tertiary care emergency department (ED) with 120,000 annual visits and 1100 hospital beds. Adult patients requiring an ultrasound-guided (US) peripheral intravenous catheter (PIVC) in the ED were eligible participants. Traditional (palpation method) insertions were excluded. Using multivariable linear regression and inverse probability weighted (IPW) linear regression, the standard group inclusive of PIVCs inserted by staff without formalized OSTICK training were compared to the interventional group inclusive of PIVCs inserted by staff with training and competency in the OSTICK training model. RESULTS: Data were collected over two time intervals: 4/1/21-9/30/21 (pre; non-OSTICK) and 10/1/22-3/31/23 (post; OSTICK). 2375 DIVA patients included 1035 (43.6%) non-OSTICK and 1340 (56.4%) OSTICK PIVCs. Overall, OSTICK PIVCs had a higher proportion of upper arm or forearm placements (94.6% vs 57.4%; p < 0.001), 20 gauge catheters (97.1% vs 92.3%; p < 0.001), and left-sided placements (54.4% vs 43.5%; p < 0.001). 62.7% of OSTICK PIVCs were placed by ED technicians, compared to 25.5% in the non-OSTICK group (p < 0.001). OSTICK PIVCs were placed on the first attempt 86.2% of the time and by the second attempt 95.4% of the time. In a subanalysis of 1343 hospitalized patients (689 (51.3%) OSTICK vs 654 (48.7%) non-OSTICK), OSTICK PIVCs survived for a median of 92% of the patient's hospital length of stay, compared to non-OSTICK PIVCs at 74% (p < 0.001). CONCLUSIONS: Formalized vascular access training in the ED leads to improved adherence to best practices for PIVC insertion, high success of cannulation with minimal attempts, and improved PIVC functionality during hospitalization for DIVA patients. Importantly, these outcomes are sustainable as they were captured 12 months after implementation of the program.

Evaluating the impact of external forces on peripheral intravenous catheter movement using ultrasound: A randomized pilot study.

BACKGROUND: A major contributor to peripheral intravenous catheter (PIVC) failure may be related to PIVC movement within the vein which is associated with vein wall damage. The magnitude of PIVC movement against the vein wall has not previously been quantified. This study aimed to examine PIVC movement within the vein when minor forces were applied to the PIVC. METHODS: This was a prospective, pilot trial including healthy volunteers in an outpatient research laboratory. The primary objective was to examine the in movement (millimeters) of the PIVC using ultrasound with external pull forces (4, 5, and 6 lbs; 1.8, 2.3, and 2.7 kg, respectively) applied to the PIVC in random order. RESULTS: Participants (N = 11) were aged 40.36 ± 16.10 years with 54.55% being Male. Mean ± SD PIVC movement for 4, 5, and 6 lbs of force was 4.65 ± 1.88, 3.88 ± 2.28, and 5.25 ± 2.06 mm, respectively. There was substantial PIVC movement when a force was applied to the PIVC, but no statistically significant difference between 4, 5, and 6 lb forces (p > 0.05). CONCLUSION: When external pull forces were applied to the PIVC, substantial PIVC movement within the vein occurred in a healthy population. Strategies that reduce PIVC movement and/or remove or limit external pull forces from the PIVC are needed. Future studies on hospitalized patients are warranted to quantify vein wall injury and PIVC failure due to PIVC movement from various pull forces.

Operation STICK: A vascular access specialty program for the generalist emergency medicine clinician.

OBJECTIVE: Comprehensive education and training programs are urgently needed to improve vascular access outcomes in the emergency department (ED). This study aimed to demonstrate the success of a formalized vascular access program in developing competent ED clinicians in traditional and ultrasound-guided insertion methods. METHODS: This was a retrospective observational study exploring the success of trainees in obtaining competency in peripheral vascular access at an academic suburban ED with 120,000 annual visits. Eligible participants included healthcare workers that enrolled in the Operation STICK vascular access program and perform vascular access procedures as an aspect of their clinical practice. Competency in vascular access included both traditional and ultrasound-guided (US) peripheral intravenous catheter (PIVC) insertions. Competency was defined as demonstration of successful insertion of one traditional and one US PIVC in compliance with checklist. The primary objective was competency. Secondary objectives included trainee time to competency, trainee number of line encounters, and changes in program competency achievements over time. RESULTS: From October 15, 2021, to April 15, 2023, 141 clinicians participated in peripheral vascular access training via the Operation STICK model, which included 72 (51.1%) nurses, 52 (36.9%) ED technicians, and 17 (12.0%) healthcare personnel with other medical training. Clinicians overall reported an average of 5.6 years of experience inserting peripheral intravenous catheters (PIVCs) and 23 (16.3%) had experience with using ultrasound. About 122 (86.5%) clinicians successfully completed the program and demonstrated competency in traditional and ultrasound-guided techniques. Time to competency varied over time, with a median of 124 days in the early phase, 32.5 days middle phase, and 10.6 h over 9.5 days in the later phase of the program (p < 0.001). CONCLUSIONS: Achieving competency in PIVC insertion necessitates a focused effort on refining and systematizing education and training approaches. Recognizing the inherent challenges present in ED settings, it is feasible to effectively and efficiently train emergency clinicians to be expert in both basic and advanced PIVC placement techniques through participation in a well-organized vascular access training program.

Effect of seven anti-tuberculosis treatment regimens on sputum microbiome: a retrospective analysis of the HIGHRIF study 2 and PanACEA MAMS-TB clinical trials.

BACKGROUND: Respiratory tract microbiota has been described as the gatekeeper for respiratory health. We aimed to assess the impact of standard-of-care and experimental anti-tuberculosis treatment regimens on the respiratory microbiome and implications for treatment outcomes. METHODS: In this retrospective study, we analysed the sputum microbiome of participants with tuberculosis treated with six experimental regimens versus standard-of-care who were part of the HIGHRIF study 2 (NCT00760149) and PanACEA MAMS-TB (NCT01785186) clinical trials across a 3-month treatment follow-up period. Samples were from participants in Mbeya, Kilimanjaro, Bagamoyo, and Dar es Salaam, Tanzania. Experimental regimens were composed of different combinations of rifampicin (R), isoniazid (H), pyrazinamide (Z), ethambutol (E), moxifloxacin (M), and a new drug, SQ109 (Q). Reverse transcription was used to create complementary DNA for each participant's total sputum RNA and the V3-V4 region of the 16S rRNA gene was sequenced using the Illumina metagenomic technique. Qiime was used to analyse the amplicon sequence variants and estimate alpha diversity. Descriptive statistics were applied to assess differences in alpha diversity pre-treatment and post-treatment initiation and the effect of each treatment regimen. FINDINGS: Sequence data were obtained from 397 pre-treatment and post-treatment samples taken between Sept 26, 2008, and June 30, 2015, across seven treatment regimens. Pre-treatment microbiome (206 genera) was dominated by Firmicutes (2860 [44%] of 6500 amplicon sequence variants [ASVs]) at the phylum level and Streptococcus (2340 [36%] ASVs) at the genus level. Two regimens had a significant depressing effect on the microbiome after 2 weeks of treatment, HR20mg/kgZM (Shannon diversity index p=0·0041) and HR35mg/kgZE (p=0·027). Gram-negative bacteria were the most sensitive to bactericidal activity of treatment with the highest number of species suppressed being under the moxifloxacin regimen. By week 12 after treatment initiation, microbiomes had recovered to pre-treatment level except for the HR35mg/kgZE regimen and for genus Mycobacterium, which did not show recovery across all regimens. Tuberculosis culture conversion to negative by week 8 of treatment was associated with clearance of genus Neisseria, with a 98% reduction of the pre-treatment level. INTERPRETATION: HR20mg/kgZM was effective against tuberculosis without limiting microbiome recovery, which implies a shorter efficacious anti-tuberculosis regimen with improved treatment outcomes might be achieved without harming the commensal microbiota. FUNDING: European and Developing Countries Clinical Trials Partnership and German Ministry of Education and Research.

Editorial on the Special Issue "Chitosan Functional Hydrogels: Synthesis and Applications".

Chitin, a polysaccharide composed of ß-(1-4)-linked 2-deoxy-2-acetamido-d-glucose units, is found in cell walls of different organisms, including crustaceans, fungi, insects, some algae, microorganisms, and some invertebrate animals, and its deacetylation into chitosan confers it with incredible chemical versatility allowing it to be processed into numerous products [...].

Protocol for a feasibility randomized controlled trial to evaluate the efficacy, safety and tolerability of N-acetylcysteine in reducing adverse drug reactions among adults treated for multidrug-resistant tuberculosis in Tanzania.

BACKGROUND: Adverse drug reactions (ADRs) frequently occur in patients using second-line anti-tuberculosis medicine for treatment of multidrug resistant tuberculosis (MDR-TB). ADRs contribute to treatment interruptions which can compromise treatment response and risk acquired drug resistance to critical newer drugs such as bedaquiline, while severe ADRs carry considerable morbidity and mortality. N-acetylcysteine (NAC) has shown promise in reducing ADRs for medications related to TB in case series or randomized controlled trials in other medical conditions, yet evidence is lacking in MDR-TB patients. TB endemic settings have limited capacity to conduct clinical trials. We designed a proof-of-concept clinical trial primarily to explore the preliminary evidence on the protective effect of NAC among people treated for MDR-TB with second-line anti-TB medications. METHODS: This is a proof-of-concept randomized open label clinical trial with 3 treatment arms including a control arm, an interventional arm of NAC 900 mg daily, and an interventional arm of NAC 900 mg twice-daily administered during the intensive phase of MDR-TB treatment. Patients initiating MDR-TB treatment will be enrolled at Kibong'oto National Center of Excellence for MDR-TB in the Kilimanjaro region of Tanzania. The minimum anticipated sample size is 66; with 22 participants in each arm. ADR monitoring will be performed at baseline and daily follow-up over 24 weeks including blood and urine specimen collection for hepatic and renal function and electrolyte abnormalities, and electrocardiogram. Sputum will be collected at baseline and monthly thereafter and cultured for mycobacteria as well as assayed for other molecular targets of Mycobacterium tuberculosis. Adverse drug events will be analysed over time using mixed effect models. Mean differences between arms in change of the ADRs from baseline (with 95% confidence intervals) will be derived from the fitted model. DISCUSSION: Given that NAC promotes synthesis of glutathione, an intracellular antioxidant that combats the impact of oxidative stress, it may protect against medication induced oxidative damage in organs such as liver, pancreas, kidney, and cells of the immune system. This randomized controlled trial will determine if NAC leads to fewer ADRs, and if this protection is dose dependent. Fewer ADRs among patients treated with MDR-TB may significantly improve treatment outcomes for multidrug regimens that necessitate prolonged treatment durations. Conduct of this trial will set the needed infrastructure for clinical trials. TRIAL REGISTRATION: PACTR202007736854169 Registered 03 July 2020.

Pharmacokinetic-Pharmacodynamic Determinants of Clinical Outcomes for Rifampin-Resistant Tuberculosis: A Multisite Prospective Cohort Study.

BACKGROUND: Rifampin-resistant and/or multidrug-resistant tuberculosis (RR/MDR-TB) treatment requires multiple drugs, and outcomes remain suboptimal. Some drugs are associated with improved outcome. It is unknown whether particular pharmacokinetic-pharmacodynamic relationships predict outcome. METHODS: Adults with pulmonary RR/MDR-TB in Tanzania, Bangladesh, and the Russian Federation receiving local regimens were enrolled from June 2016 to July 2018. Serum was collected after 2, 4, and 8 weeks for each drug's area under the concentration-time curve over 24 hours (AUC0-24). Quantitative susceptibility of the M. tuberculosis isolate was measured by minimum inhibitory concentrations (MICs). Individual drug AUC0-24/MIC targets were assessed by adjusted odds ratios (ORs) for favorable treatment outcome, and hazard ratios (HRs) for time to sputum culture conversion. K-means clustering algorithm separated the cohort of the most common multidrug regimen into 4 clusters by AUC0-24/MIC exposures. RESULTS: Among 290 patients, 62 (21%) experienced treatment failure, including 30 deaths. Moxifloxacin AUC0-24/MIC target of 58 was associated with favorable treatment outcome (OR, 3.75; 95% confidence interval, 1.21-11.56; P = .022); levofloxacin AUC0-24/MIC of 118.3, clofazimine AUC0-24/MIC of 50.5, and pyrazinamide AUC0-24 of 379 mg × h/L were associated with faster culture conversion (HR >1.0, P < .05). Other individual drug exposures were not predictive. Clustering by AUC0-24/MIC revealed that those with the lowest multidrug exposures had the slowest culture conversion. CONCLUSIONS: Amidst multidrug regimens for RR/MDR-TB, serum pharmacokinetics and M. tuberculosis MICs were variable, yet defined parameters to certain drugs-fluoroquinolones, pyrazinamide, clofazimine-were predictive and should be optimized to improve clinical outcome. CLINICAL TRIALS REGISTRATION: NCT03559582.

Short peripheral intravenous catheter securement with cyanoacrylate glue compared to conventional dressing: A randomized controlled trial.

BACKGROUND: Short peripheral intravenous catheters (PIVCs) fail prior to completion of therapy in up to 63% of hospitalizations. This unacceptably high rate of failure has become the norm for the most common invasive procedure in all of medicine. Securement strategies may improve PIVC survival. METHODS: We conducted a prospective, single-site, parallel, two-arm randomized controlled investigation with a primary outcome of catheter failure comparing securement with standard semi-permeable dressing and clear tape (SPD) to standard semipermeable dressing and clear tape with cyanoacrylate glue (SPD + CG). Adult emergency department patients with a short PIVC and anticipated hospital duration ⩾ 48 h were enrolled and followed until IV failure or completion of therapy for up to 7 days. Secondary outcomes included complications and cost comparisons between groups. Primary outcome was assessed by intention to treat and per protocol analyses. FINDINGS: 350 patients were enrolled between November 2019 and October 2020. PIVC survival for SPD + CG was similar to SPD group with the absolute risk difference of IV failure in the intention-to-treat (-5.8%, p = 0.065) population and improved in the per protocol (-8.1%, p = 0.04) population, respectively. Kaplan-Meier survival analysis indicated there was a significant benefit of the SPD + CG at greater than 2 days of hospitalization (p = 0.04). Prior to 48 h, there was no survival enhancement to either group (p = 0.98) in the intention to treat population. In a multivariable analysis with piecewise Cox regression, when the IV was functional greater than 48 h, the risk of IV failure in the SPD + CG was 43% less than the SPD group (adjusted hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.34 to 0.97; p = 0.04). Cumulative cost related to IV during hospitalization was similar between groups with a lower incremental rescue cost in the SPD + CG group. INTERPRETATION: SPD combined with cyanoacrylate glue provides similar benefit to patients compared to SPD alone and potentially improves short PIVC survival when the IV was inserted >48 h. As this strategy is cost neutral, it could be considered in admitted patients, particularly those with longer anticipated hospital durations.

Improving Properties of Starch-Based Adhesives with Carboxylic Acids and Enzymatically Polymerized Lignosulfonates.

A novel strategy for improving wet resistance and bonding properties of starch-based adhesives using enzymatically polymerized lignosulfonates and carboxylic acids as additives was developed. Therefore, lignosulfonates were polymerized by laccase to a molecular weight of 750 kDa. Incorporation of low concentrations (up to 1% of the starch weight) of 1,2,3,4-butanetetracarboxylic acid (BTCA) led to further improvement on the properties of the adhesives, while addition of greater amounts of BTCA led to a decrease in the properties measured due to large viscosity increases. Great improvements in wet-resistance from 22 to 60 min and bonding times (from 30 to 20 s) were observed for an adhesive containing 8% enzymatically polymerized lignin and 1% BTCA. On the other hand, the addition of citric acid (CA) deteriorated the properties of the adhesives, especially when lignosulfonate was present. In conclusion, this study shows that the addition of the appropriate amount of enzymatically polymerized lignosulfonates together with carboxylic acids (namely BTCA) to starch-based adhesives is a robust strategy for improving their wet resistance and bonding times.

Investigative study of hemodilution ratio: 4Vs for vein diameter, valve, velocity, and volumetric blood flow as factors for optimal forearm vein selection for intravenous infusion.

BACKGROUND: Multimodal research and guidelines recognize veins in the forearm used for peripheral intravenous catheter (PIVC) insertion can optimize dwell time. Yet, many PIVCs are still placed in areas of flexion or suboptimal locations such as the back of the hand causing premature failure of >50%. This study identified characteristics of the forearm cephalic vein that make the anatomical location highly successful for PIVC insertion. The goal was to increase the understanding of the human vasculature in association with fluid mechanics in veins above the wrist and below the antecubital fossa. METHODOLOGY: A prospective in-vivo study with 10 consented healthy human volunteers (HHVs) was performed with Color Pulse Wave Doppler Ultrasound that captured high-resolution video and images of vein diameter, velocity of blood flow, and location of venous valves in the forearm. RESULTS: Forearm vein diameter was not directly correlated with higher or lower Velocity of Blood Flow (0.58 cm = 3.0 cm/s). However, Volumetric Blood Flow rates tended to be lower (2.51-8.28 mL/min) with Vein Diameters smaller than 0.29 cm. Ultrasound assessments and Volumetric Blood Flow calculations confirmed natural turbulence in blood and retrograde blood reflux correlated with venous valves opening and closing. Areas of turbulence, with pulse flushing, created backflow with retrograde blood flow around and into the catheter. CONCLUSIONS: Placement of long PIVCs in the cephalic veins of the upper forearm yield adequate flow and hemodilution capacity for veins with at least a 3 to 1 hemodilution ratio. The data from this study, along with previous research, suggest that PIVC placement in the cephalic vein, based on selection criteria, may help to reduce or eliminate intravenous complications such as chemical or mechanical thrombophlebitis causing premature catheter failure. Application of these investigational principles may result in better outcomes and catheter longevity for patients who require intravenous infusions.

Enzymatic synthesis of wet-resistant lignosulfonate-starch adhesives.

This work describes a new method for improving the properties, mainly the wet-resistance, of starch-based adhesives using enzymatically polymerized lignosulfonates. A correlation of viscosity with molecular weight was found, allowing simple control of enzymatic polymerization of lignosulfonates. Incorporation of lignosulfonates polymerized from 29 kDa to > 4500 kDa using laccase led to a considerable increase in wet-resistance (from 15 to 20 min for the laminating glue and from 150 to 1200 min for the bag glue) while not affecting (for the laminating glue) or even improving the bonding time (from 80 to 60 s for the bag glue). Finally, the effect of active laccase in the final adhesive was investigated by enzymatic inactivation using NaN3 before formulation of the glue, as well as by extra laccase addition. In conclusion, this study shows that enzymatically polymerized lignosulfonate is a robust strategy for improving wet resistance of starch-based adhesives.

Enzymatic Conversion of Lignosulfonate into Wood Adhesives: A Next Step towards Fully Biobased Composite Materials.

This study investigates the effect of the enzymatic polymerization of lignosulfonate for the formulation of a lignosulfonate-based adhesive. For this, beech lamellas were glued together and tested according to the EN 302-1 standard. The results showed that the laccase-polymerized lignosulfonate-based wood adhesives (LS-p) had similar mechanical properties as a standard carpenter's glue (PVAc-based D3 class white glue), as no significant difference in tensile shear strength between these two adhesive types was found. However, carpenter's glue showed almost 100% wood failure, while with the lignosulfonate-based wood glue, the samples failed, mainly in the glueline. Pre-polymerization of LS-p is the most critical factor to achieve the required viscosity, which is also connected to the wetting properties and the resulting tensile shear strength. The longer the pre-polymerization, the higher the viscosity of the LS-p adhesive, with the tensile shear strength reaching a plateau. The presented data show the potential of using enzymatically pre-polymerized lignosulfonate as a well-performing wood adhesive. Further development and optimization of the pre-polymerization process is required, which is also important to push towards upscaling and practical applications.

Outcome of caudal superficial epigastric axial pattern flaps in dogs and cats: 70 cases (2007-2020).

OBJECTIVES: To describe the outcome and complications associated with the use of caudal superficial epigastric axial pattern flaps in dogs and cats. MATERIAL AND METHODS: Multicentre retrospective review and descriptive study of clinical records of dogs and cats having undergone caudal superficial epigastric axial pattern flaps between 2007 and 2020. Data retrieved included signalment, aetiology of surgical defect, tumour type, presence/absence of clean surgical margins, presence/absence of post-operative wound infection, use of peri- and post-operative antibiotics, duration of anaesthesia, duration of surgery, presence and duration of hypothermia, presence and duration of hypotension, presence/absence of post-operative surgical drain and length of caudal superficial epigastric axial pattern flap. The incidence of complications and outcomes were documented. RESULTS: Seventy cases met the inclusion criteria; 51 dogs and 19 cats. In dogs, 67% of cases developed complications (59% minor, 8% major) and 33% had uneventful wound healing. In cats, 53% of cases developed complications, (47% minor, 5% major) and 47% had uneventful wound healing. In dogs, the percentage of cases experiencing dehiscence, necrosis, seroma, oedema and post-operative infection was 31%, 29%, 26%, 26% and 16% respectively. In cats, this was 26%, 16%, 11%, 0% and 5% respectively. A good overall outcome was seen in 77% of dogs and 79% of cats. A poor overall outcome was seen in 4% of dogs and 0% of cats. CLINICAL SIGNIFICANCE: Caudal superficial epigastric axial pattern flaps are traditionally thought more robust than other flaps, yet complication rates remain high, despite a high overall success rate.

Whole-genome sequencing of SARS-CoV-2 isolates from symptomatic and asymptomatic individuals in Tanzania.

Background: Coronavirus Disease-2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) accounts for considerable morbidity and mortality globally. Paucity of SARS-CoV-2 genetic data from Tanzania challenges in-country tracking of the pandemic. We sequenced SARS-CoV-2 isolated in the country to determine circulating strains, mutations and phylogenies and finally enrich international genetic databases especially with sequences from Africa. Methods: This cross-sectional study utilized nasopharyngeal swabs of symptomatic and asymptomatic adults with positive polymerase chain reaction tests for COVID-19 from January to May 2021. Viral genomic libraries were prepared using ARTIC nCoV-2019 sequencing protocol version three. Whole-genome sequencing (WGS) was performed using Oxford Nanopore Technologies MinION device. In silico genomic data analysis was done on ARTIC pipeline version 1.2.1 using ARTIC nCoV-2019 bioinformatics protocol version 1.1.0. Results: Twenty-nine (42%) out of 69 samples qualified for sequencing based on gel electrophoretic band intensity of multiplex PCR amplicons. Out of 29 isolates, 26 were variants of concern [Beta (n = 22); and Delta (n = 4)]. Other variants included Eta (n = 2) and B.1.530 (n = 1). We found combination of mutations (S: D80A, S: D215G, S: K417N, ORF3a: Q57H, E: P71L) in all Beta variants and absent in other lineages. The B.1.530 lineage carried mutations with very low cumulative global prevalence, these were nsp13:M233I, nsp14:S434G, ORF3a:A99S, S: T22I and S: N164H. The B.1.530 lineage clustered phylogenetically with isolates first reported in south-east Kenya, suggesting regional evolution of SARS-CoV-2. Conclusion: We provide evidence of existence of Beta, Delta, Eta variants and a locally evolving lineage (B.1.530) from samples collected in early 2021 in Tanzania. This work provides a model for ongoing WGS surveillance that will be required to inform on emerging and circulating SARS-CoV-2 diversity in Tanzania and East Africa.

Oxidation of Various Kraft Lignins with a Bacterial Laccase Enzyme.

Modification of kraft lignin (KL), traditionally uses harsh and energy-demanding physical and chemical processes. In this study, the potential of the bacterial laccase CotA (spore coating protein A) for oxidation of KL under mild conditions was assessed. Thereby, the efficiency of CotA to oxidize both softwood and hardwood KL of varying purity at alkaline conditions was examined. For the respective type of wood, the highest oxidation activity by CotA was determined for the medium ash content softwood KL (MA_S) and the medium ash content hardwood KL (MA_H), respectively. By an up to 95% decrease in fluorescence and up to 65% in phenol content coupling of the structural lignin units was indicated. These results correlated with an increase in viscosity and molecular weight, which increased nearly 2 and 20-fold for MA_H and about 1.3 and 6.0-fold for MA_S, respectively. Thus, this study confirms that the CotA laccase can oxidize a variety of KL at alkaline conditions, while the origin and purity of KL were found to have a major impact on the efficiency of oxidation. Under the herein tested conditions, it was observed that the MA_H KL showed the highest susceptibility to CotA oxidation when compared to the other hardwood KLs and the softwood KLs. Therefore, this could be a viable method to produce sustainable resins and adhesives.

Pharmacodynamic biomarkers for quantifying the mycobacterial effect of high doses of rifampin in patients with rifampin-susceptible pulmonary tuberculosis.

Background: Suboptimal drug exposure in patients with drug-susceptible tuberculosis (DS-TB) can drive treatment failure. Pharmacodynamics (PD) biomarkers such as the plasma TB drug-activity (TDA) assay may guide dose finding studies and predict microbiological outcomes differently than conventional indices. Methods: A study was nested from phase 2b randomized double-blind controlled trial of Tanzanian patients who received a 600 mg, 900 mg, or 1200 mg with a standard dose for DS-TB. Serum at 6 weeks collected over 24-h at 2-h intervals was collected for rifampin area under the concentration-time curve relative to minimum inhibitory concentration (AUC0-24/MIC) or peak concentration and MIC (Cmax/MIC). TDA was the ratio of time-to-positive growth of the patient's Mycobacterium tuberculosis isolates with and without coculture of patient's plasma collected at Cmax. Spearman's rank correlation (r) between PD parameters and culture convention on both liquid and solid culture media. Results: Among 10 patients, 600 mg (3), 900 mg (3), and 1200 mg (4) of rifampin dosages. The mean ± standard deviation (SD) of AUC0-24/MIC for patients on 600 mg was 168 ± 159 mg·h/L, on 900 mg was 169 ± 166 mg·h/L, and on 1200 mg was 308 ± 238 mg·h/L. The mean-TDA (SD) was 2.56 (±0.75), 1.5 (±0.59), and 2.29 (±1.08) for patients on 600 mg, 900 mg, and 1200 mg rifampin doses, respectively. Higher TDA values correlated with faster time to culture convention on both liquid (r = -0.55, P = 0.099) and solid media (r = -0.65, P = 0.04). Conclusions: TDA and rifampin AUC0-24/MIC did not trend as expected with rifampin dose, but TDA better predicted the time to sputum culture conversion. TDA may provide additional discrimination in predicting treatment response for some regimens distinct from plasma exposure relative to MIC or mg/kg dose.

Enzyme Catalyzed Copolymerization of Lignosulfonates for Hydrophobic Coatings.

Enzymatic polymerization of lignin can generate a variety of value-added products concomitantly replacing fossil-based resources. In line with this approach, a laccase from the thermophilic fungus Myceliophthora thermophila (MtL) was used to couple a hydrophobicity enhancing fluorophenol (FP) molecule, namely 4-[4-(trifluoromethyl)phenoxy]phenol (4,4-F3MPP), as a model substrate onto lignosulfonate (LS). During the coupling reaction changes in fluorescence, phenol content, viscosity and molecular weight (size exclusion chromatography; SEC) were monitored. The effects of enzymatic coupling of FP onto LS on hydrophobicity were investigated by the means of water contact angle (WCA) measurement and determination of swelling capacity. Full polymerization of LS resulting in the production of water-insoluble polymers was achieved at a pH of 7 and 33°C. Incorporation of 2% (w/v) of FP led to an increase in WCA by 59.2% while the swelling capacity showed a decrease by 216.8%. Further, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicated successful covalent coupling of the FP molecule onto LS by an emerging peak at 1,320 cm-1 in the FTIR spectrum and the evidence of Fluor in the XPS spectrum. This study shows the ability of laccase to mediate the tailoring of LS properties to produce functional polymers.

Rapid improvement in symptoms and physical function following ibrutinib initiation in chronic lymphocytic leukemia and the associated changes in plasma cytokines.

A prospective pilot study was carried out on 34 CLL patients treated with ibrutinib, evaluating the effects on symptoms and physical function with changes in plasma exosomes (EXs), ß2-microglobulin (ß2M) and 26 plasma cytokines. The revised Edmonton Symptom Assessment Scale (ESAS-R) demonstrated moderate fatigue, shortness of breath and a sense of unwellness before treatment, which significantly improved within 2 weeks of starting ibrutinib. These changes were associated with a rapid improvement in sit-to-stand and 4 m walking speeds. The plasma levels of CCL11, IL-7, -8 and -10 dropped initially while the levels of TNF-α/-ß, CCL3, CCL4, CCL17, and IL-16 continued to decline for 12 months. Despite the initial lymphocytosis, plasma ß2M levels fell but no consistent change in plasma EXs occurred. Thus, ibrutinib can produce a rapid and sustained improvement in symptoms and physical function in CLL, associated with a decline in multiple plasma cytokines.