Substrate-Assisted Catalysis Unifies Two Families of Chitinolytic Enzymes

Hen egg-white lysozyme has long been the paradigm for enzymatic glycosyl hydrolysis with retention of configuration, with a protonated carboxylic acid and a deprotonated carboxylate participating in general acid-base catalysis. In marked contrast, the retaining chitin degrading enzymes from glycosyl hydrolase families 18 and 20 all have a single glutamic acid as the catalytic acid but lack a nucleophile on the enzyme. Both families have a catalytic (βα)8-barrel domain in common. X-ray structures of three different chitinolytic enzymes complexed with substrates or inhibitors identify a retaining mechanism involving a protein acid and the carbonyl oxygen atom of the substrate’s C2 N-acetyl group as the nucleophile. These studies unambiguously demonstrate the distortion of the sugar ring toward a sofa conformation, long postulated as being close to that of the transition state in glycosyl hydrolysis.

Microbes as engines of ecosystem function : When does community structure enhance predictions of ecosystem processes?

FUNDING This work was supported by NSF grant DEB-1221215 to DN, as well as grants supporting the generation of our datasets as acknowledged in their original publications and in Supplementary Table S1. ACKNOWLEDGMENT We thank the USGS Powell Center ‘Next Generation Microbes’ working group, anonymous reviews, Brett Melbourne, and Alan Townsend for valuable feedback on this project.Peer reviewedPublisher PD

Thymic stromal lymphopoietin (TSLP) acts as a potent mucosal adjuvant for HIV-1 gp140 vaccination in mice

The development of a successful vaccine against HIV is likely to require the induction of strong and long-lasting humoral immune responses at the mucosal portal of virus entry. Hence, the design of a vaccine strategy able to induce mucosal antibodies and in particular specific IgA, may be crucial to providing immune protection. Nasal immunisation is known to induce specific IgG and IgA responses in the cervicovaginal mucosa; however, there is an urgent need for the development of safe, effective and accessible mucosal adjuvants for nasal application in humans. To reduce the potential for adverse events associated with some nasal adjuvants, we have assessed whether the B-cell-activating cytokines APRIL, BAFF and TSLP enhance humoral immune responses to HIV-1 gp140. Following intranasal immunisation, TSLP but not APRIL or BAFF induced strong humoral responses both in serum and mucosa. The adjuvant effect of TSLP on humoral responses was similar to that of cholera toxin (CT). The use of TSLP as an adjuvant skewed both the cellular and humoral immune responses towards Th2 cells. This is the first time that TSLP has been demonstrated to have a positive effect as a mucosal adjuvant, and specifically to promote mucosal and systemic responses to HIV gp140

Evaluation and recommendations of the oral health, oral function, and orofacial aesthetics-related measures of the ICHOM Standard Set for Cleft Lip and Palate

This study was performed to evaluate the efficacy of outcome measures for the orofacial domain included in the International Consortium for Health Outcomes Measurement Standard Set for Cleft Lip and Palate (ICHOM-SCS). In this multicentre study involving two cleft centres, suggestions to optimize the type and timing of outcome measures were made based on data and clinical experience. Patient-reported outcome measures (PROMs) (CLEFT-Q Jaw, Teeth, Eating/Drinking; Child Oral Health Impact Profile—Oral Symptoms Scale (COHIP-OSS)) and clinical outcome measures (caries experience and dental occlusion) data were collected retrospectively for age 5, 8, 10, 12, 19, and 22 years. The data were categorized by cleft type and analysed within and between age groups using Spearman correlation, the distribution of responses per item, a two-sample test for equality of proportions, and effect plots. Most correlations between PROMs and clinical outcome measures were weak (r &lt; 0.5), suggesting PROMs and clinical outcome measures complement each other. The COHIP-OSS and CLEFT-Q Eating/Drinking barely detected problems in any patient category and are no longer recommended. A suitable alternative appears complex to find; outcomes of this study and the recent literature doubt an added value. Similar problems were found in the CLEFT-Q Jaw at time-point 12 years. Therefore, time-points 15 and 17 years are currently suggested.</p

Differences in the surgical and financial burden of four protocols for unilateral cleft lip and palate

The treatment of unilateral cleft lip and palate (UCLP) involves up to four primary surgeries to restore oral function. This study was performed to evaluate the surgical burden and direct healthcare costs of four UCLP surgical protocols at Erasmus University Medical Centre, Rotterdam, to guide optimal protocol selection. This retrospective cohort study included UCLP patients treated during 1990-2024. The patients were categorized into groups based on the hard palate closure timing: Oslo protocol (OP), one-stage palatoplasty protocol (OSPP), early delayed hard palate closure protocol (E-DHPCP), and late delayed hard palate closure protocol (L-DHPCP). Primary surgeries were analysed for operative duration (OD) and length of hospital stay (LOS), and their associated costs were estimated. Overall, 331 patients were included. Mean cumulative OD was significantly shorter for L-DHPCP and OSPP when compared to E-DHPCP and OP, while mean cumulative LOS was significantly longer for E-DHPCP compared to the other protocols. Mean cumulative OD was 408, 465, 425, and 507 min, and mean cumulative LOS was 3.95, 4.84, 4.07, and 4.11 nights for L-DHPCP, E-DHPCP, OSPP, and OP, respectively. Mean total costs were estimated at €17,858, €20,791, €18,545, and €21,158, respectively. L-DHPCP and OSPP demonstrated the lowest surgical burden and direct healthcare costs, although differences were minor. Therefore, the choice between these four surgical protocols should continue to be based on clinical outcomes, rather than differences in burden and costs.</p

Comparison of two surgical protocols for the treatment of unilateral cleft lip and palate: a multidisciplinary systematic review and meta-analysis

Cleft lip; Oral surgical procedures; Treatment outcomeLlavi leporino; Procediments quirúrgics orals; Resultat del tractamentLabio leporino; Procedimientos quirúrgicos orales; Resultado del tratamientoThere is still no unanimous agreement on the optimal surgical protocol(s) for the treatment of unilateral cleft lip and palate (UCLP), and a huge variety of protocols are employed by cleft centres across the world. The aim of this systematic review and meta-analysis was to compare reported patient outcomes of the Oslo protocol (and modifications) (OP) and delayed hard palate closure protocols (DHPCP) from a multidisciplinary perspective. A systematic search of multiple databases was conducted until September 2023. Studies reporting any patient outcomes of these protocols were included. Random-effects meta-analyses were performed for evidence synthesis, including comparisons of results between the types of protocol. The quality of evidence was evaluated using the ROBINS-I tool. In total, 62 articles (42 studies) reporting patients with UCLP were reviewed, involving 1281 patients following the OP and 655 following DHPCP. Equally poor long-term sagittal maxillofacial growth was found, and similar results for velopharyngeal insufficiency and nasolabial appearance. In contrast, OP was associated with a lower rate of oronasal fistulas. Disregarding the scarcity of comparable evidence for some domains, the results of this review, overall, favour OP over DHPCP. However, caution should be taken when interpreting the results on velopharyngeal insufficiency and oronasal fistulas, since the possibility of confounding and other biases remains.Partially funded by ERN CRANIO (European Reference Network for Rare and/or Complex Craniofacial Anomalies and Ear, Nose and Throat (ENT) Disorders) in terms of personnel costs for two researchers (V. van Roey, S. Ombashi). ERN CRANIO is funded by the European Union

Comparison of a third surgical protocol for the treatment of unilateral cleft lip and palate:a multidisciplinary systematic review and meta-analysis

This systematic review and meta-analysis builds upon our previous publication on the outcomes of patients with unilateral cleft lip and palate (UCLP) treated with Oslo protocols (OP; vomerplasty during lip closure vs delayed hard palate closure protocols (DHPCP), comparing the outcomes of these two protocols with those of one-stage palatoplasty protocols (OSPP). A systematic search of the Embase, MEDLINE/PubMed, Web of Science, Cochrane, and Google Scholar databases was conducted until August 2024. In total, 162 articles (156 study groups) were reviewed, including 4040 UCLP patients following OSPP, 1632 following OP, and 791 following DHPCP. The results suggest that intrinsic maxillofacial growth disturbances are common in UCLP patients, regardless of the timing or type of palatal closure. The incidence of velopharyngeal insufficiency was significantly higher in OP (24%) when compared to DHPCP (9%), with OSPP showing an intermediate incidence (14%). However, these findings are of very low certainty due to evident non-reporting bias and limited data. In contrast, OP and OSPP showed lower oronasal fistula (ONF) rates (7% for OP, 10% for OSPP) compared to DHPCP (20%). Altogether, OSPP and OP are favoured over DHPCP due to the lower incidences of ONF, better overall speech outcomes, and fewer primary surgeries.</p

FACE-Q craniofacial module:Normative data from a Dutch population in adolescence and young adulthood

Background: The FACE-Q Craniofacial Module is a patient-reported outcome measure (PROM) that has undergone rigorous psychometric validation in patients with visible or functional facial differences, including patients with craniosynostosis. Normative data for the FACE-Q Craniofacial Module scales are currently unavailable for unaffected controls. This study aims to collect and analyze normative FACE-Q Craniofacial Module data from a Dutch population sample. Method: Dutch nationals aged 16–24 years without visible or functional facial differences were recruited by a third-party company for the online survey. Respondents completed FACE-Q Craniofacial Module scales from the appearance and health-related quality of life domains. Normative data were calculated as means and standard deviations and weighted based on national data. Results: A total of 870 individuals responded to the survey, of which 160 were excluded from the analysis because of possible visible or functional facial differences. Women had significantly lower scores on many scales. Age influenced the scores for the face, forehead, head shape, and appearance distress scales significantly, with higher scores as age increases. Participants with a practical background only had significantly lower scores on the school functioning scale. Conclusion: Normative values for FACE-Q Craniofacial Module scales are provided derived from a Dutch sample of adolescents and young adults. This study demonstrates that sex and age had a significant influence on multiple FACE-Q scales. These normative values provide more context when interpreting FACE-Q scores in patients with visible or functional facial differences.</p

Revealing the role of CO during CO2 hydrogenation on Cu surfaces with in situ soft X-ray spectroscopy

The reactions of H2, CO2, and CO gas mixtures on the surface of Cu at 200 °C, relevant for industrial methanol synthesis, are investigated using a combination of ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and atmospheric-pressure near edge X-ray absorption fine structure (AtmP-NEXAFS) spectroscopy bridging pressures from 0.1 mbar to 1 bar. We find that the order of gas dosing can critically affect the catalyst chemical state, with the Cu catalyst maintained in a metallic state when H2 is introduced prior to the addition of CO2. Only on increasing the CO2 partial pressure is CuO formation observed that coexists with metallic Cu. When only CO2 is present, the surface oxidizes to Cu2O and CuO, and the subsequent addition of H2 partially reduces the surface to Cu2O without recovering metallic Cu, consistent with a high kinetic barrier to H2 dissociation on Cu2O. The addition of CO to the gas mixture is found to play a key role in removing adsorbed oxygen that otherwise passivates the Cu surface, making metallic Cu surface sites available for CO2 activation and subsequent conversion to CH3OH. These findings are corroborated by mass spectrometry measurements, which show increased H2O formation when H2 is dosed before rather than after CO2. The importance of maintaining metallic Cu sites during the methanol synthesis reaction is thereby highlighted, with the inclusion of CO in the gas feed helping to achieve this even in the absence of ZnO as the catalyst support