Molecular mechanism for strengthening E-cadherin adhesion using a monoclonal antibody.

E-cadherin (Ecad) is an essential cell-cell adhesion protein with tumor suppression properties. The adhesive state of Ecad can be modified by the monoclonal antibody 19A11, which has potential applications in reducing cancer metastasis. Using X-ray crystallography, we determine the structure of 19A11 Fab bound to Ecad and show that the antibody binds to the first extracellular domain of Ecad near its primary adhesive motif: the strand-swap dimer interface. Molecular dynamics simulations and single-molecule atomic force microscopy demonstrate that 19A11 interacts with Ecad in two distinct modes: one that strengthens the strand-swap dimer and one that does not alter adhesion. We show that adhesion is strengthened by the formation of a salt bridge between 19A11 and Ecad, which in turn stabilizes the swapped ß-strand and its complementary binding pocket. Our results identify mechanistic principles for engineering antibodies to enhance Ecad adhesion.

SARS-CoV-2 polyprotein substrate regulates the stepwise Mpro cleavage reaction.

The processing of the Coronavirus polyproteins pp1a and pp1ab by the main protease Mpro to produce mature proteins is a crucial event in virus replication and a promising target for antiviral drug development. Mpro cleaves polyproteins in a defined order, but how Mpro and/or the polyproteins determine the order of cleavage remains enigmatic due to a lack of structural information about polyprotein-bound Mpro. Here, we present the cryo-EM structures of SARS-CoV-2 Mpro in an apo form and in complex with the nsp7-10 region of the pp1a polyprotein. The complex structure shows that Mpro interacts with only the recognition site residues between nsp9 and nsp10, without any association with the rest of the polyprotein. Comparison between the apo form and polyprotein-bound structures of Mpro highlights the flexible nature of the active site region of Mpro, which allows it to accommodate ten recognition sites found in the polyprotein. These observations suggest that the role of Mpro in selecting a preferred cleavage site is limited and underscores the roles of the structure, conformation, and/or dynamics of the polyproteins in determining the sequence of polyprotein cleavage by Mpro.

Perspectives of carriers of X-linked retinal diseases on genetic testing and gene therapy: A global survey.

Female carriers of X-linked inherited retinal diseases (IRDs) are burdened with potentially passing their disease-causing variant to future generations, as well as exhibiting signs of retinal disease themselves. This study aimed to investigate carriers' experiences of genetic testing, emotions relating to having affected children, and their knowledge regarding genetic testing and gene therapy. An online survey was advertised to self-identified carriers worldwide. Two hundred and twenty-eight carriers completed the survey with mean age of 51 years (SD ± 15.0). A majority of respondents resided in the United States of America (51%), Australia (19%), and the United Kingdom (14%). Most carriers identified with feelings of guilt (70%), concern (91%), and anxiety (88%) for their child. Female carriers who had given birth to children had significantly greater gene therapy knowledge compared to carriers who had not (p < 0.05). Respondents agreed that their eyecare provider and general practitioner helped them understand their condition (63%), however, few carriers reported receiving psychological counselling (9%) or family planning advice (5%). Most respondents (78%) agreed that gene therapy should be available to carriers. This study emphasises the importance of providing appropriate counselling to female carriers and illustrates the motivation of many to participate in emerging treatment options, such as gene therapy.

Genetic testing and gene therapy in retinal diseases: Knowledge and perceptions of optometrists in Australia and New Zealand.

With advances in gene-based therapies for heritable retinal diseases, primary eye care clinicians should be informed on ocular genetics topics. This cross-sectional survey evaluated knowledge, attitudes, and concerns regarding genetic testing and gene therapy for retinal diseases among optometrists in Australia and New Zealand. Survey data included practitioner background, attitudes and practices towards genetic testing for monogenic inherited retinal disease (IRDs) and age-related macular degeneration, and knowledge of ocular genetics and gene therapy. Responses were received from 516 optometrists between 1 April and 31 December 2022. Key perceived barriers to accessing genetic testing were lack of clarity on referral pathways (81%), cost (65%), and lack of treatment options if a genetic cause is identified (50%). Almost all respondents (98%) believed that ophthalmologists should initiate genetic testing for IRDs and fewer understood the role of genetic counsellors and clinical geneticists. This study found that optometrists in Australia and New Zealand have a high level of interest in ocular genetics topics. However, knowledge gaps include referral pathways and awareness of genetic testing and gene therapy outcomes. Addressing perceived barriers to access and promoting sharing of knowledge between interdisciplinary networks can set the foundation for genetic education agendas in primary eye care.

Genetic analysis and molecular basis of G6PD deficiency among malaria patients in Thailand: implications for safe use of 8-aminoquinolines.

BACKGROUND: It was hypothesized that glucose-6-phosphate dehydrogenase (G6PD) deficiency confers a protective effect against malaria infection, however, safety concerns have been raised regarding haemolytic toxicity caused by radical cure with 8-aminoquinolines in G6PD-deficient individuals. Malaria elimination and control are also complicated by the high prevalence of G6PD deficiency in malaria-endemic areas. Hence, accurate identification of G6PD deficiency is required to identify those who are eligible for malaria treatment using 8-aminoquinolines. METHODS: The prevalence of G6PD deficiency among 408 Thai participants diagnosed with malaria by microscopy (71), and malaria-negative controls (337), was assessed using a phenotypic test based on water-soluble tetrazolium salts. High-resolution melting (HRM) curve analysis was developed from a previous study to enable the detection of 15 common missense, synonymous and intronic G6PD mutations in Asian populations. The identified mutations were subjected to biochemical and structural characterisation to understand the molecular mechanisms underlying enzyme deficiency. RESULTS: Based on phenotypic testing, the prevalence of G6PD deficiency (< 30% activity) was 6.13% (25/408) and intermediate deficiency (30-70% activity) was found in 15.20% (62/408) of participants. Several G6PD genotypes with newly discovered double missense variants were identified by HRM assays, including G6PD Gaohe + Viangchan, G6PD Valladolid + Viangchan and G6PD Canton + Viangchan. A significantly high frequency of synonymous (c.1311C>T) and intronic (c.1365-13T>C and c.486-34delT) mutations was detected with intermediate to normal enzyme activity. The double missense mutations were less catalytically active than their corresponding single missense mutations, resulting in severe enzyme deficiency. While the mutations had a minor effect on binding affinity, structural instability was a key contributor to the enzyme deficiency observed in G6PD-deficient individuals. CONCLUSIONS: With varying degrees of enzyme deficiency, G6PD genotyping can be used as a complement to phenotypic screening to identify those who are eligible for 8-aminoquinolines. The information gained from this study could be useful for management and treatment of malaria, as well as for the prevention of unanticipated reactions to certain medications and foods in the studied population.

Sal-type ABC-F proteins: intrinsic and common mediators of pleuromutilin resistance by target protection in staphylococci.

The first member of the pleuromutilin (PLM) class suitable for systemic antibacterial chemotherapy in humans recently entered clinical use, underscoring the need to better understand mechanisms of PLM resistance in disease-causing bacterial genera. Of the proteins reported to mediate PLM resistance in staphylococci, the least-well studied to date is Sal(A), a putative ABC-F NTPase that-by analogy to other proteins of this type-may act to protect the ribosome from PLMs. Here, we establish the importance of Sal proteins as a common source of PLM resistance across multiple species of staphylococci. Sal(A) is revealed as but one member of a larger group of Sal-type ABC-F proteins that vary considerably in their ability to mediate resistance to PLMs and other antibiotics. We find that specific sal genes are intrinsic to particular staphylococcal species, and show that this gene family is likely ancestral to the genus Staphylococcus. Finally, we solve the cryo-EM structure of a representative Sal-type protein (Sal(B)) in complex with the staphylococcal 70S ribosome, revealing that Sal-type proteins bind into the E site to mediate target protection, likely by displacing PLMs and other antibiotics via an allosteric mechanism.

Structure-Guided Discovery of N5-CAIR Mutase Inhibitors.

Because purine nucleotides are essential for all life, differences between how microbes and humans metabolize purines can be exploited for the development of antimicrobial therapies. While humans biosynthesize purine nucleotides in a 10-step pathway, most microbes utilize an additional 11th enzymatic activity. The human enzyme, aminoimidazole ribonucleotide (AIR) carboxylase generates the product 4-carboxy-5-aminoimidazole ribonucleotide (CAIR) directly. Most microbes, however, require two separate enzymes, a synthetase (PurK) and a mutase (PurE), and proceed through the intermediate, N5-CAIR. Toward the development of therapeutics that target these differences, we have solved crystal structures of the N5-CAIR mutase of the human pathogens Legionella pneumophila (LpPurE) and Burkholderia cenocepacia (BcPurE) and used a structure-guided approach to identify inhibitors. Analysis of the structures reveals a highly conserved fold and active site architecture. Using this data, and three additional structures of PurE enzymes, we screened a library of FDA-approved compounds in silico and identified a set of 25 candidates for further analysis. Among these, we identified several new PurE inhibitors with micromolar IC50 values. Several of these compounds, including the α1-blocker Alfuzosin, inhibit the microbial PurE enzymes much more effectively than the human homologue. These structures and the newly described PurE inhibitors are valuable tools to aid in further studies of this enzyme and provide a foundation for the development of compounds that target differences between human and microbial purine metabolism.

Survey of perspectives of people with inherited retinal diseases on ocular gene therapy in Australia.

Many gene therapies are in development for treating people with inherited retinal diseases (IRD). We hypothesized that potential recipients of gene therapy would have knowledge gaps regarding treatment. We aimed to assess knowledge, attitudes, and perceptions of genetic therapies among potential recipients with IRD, using a novel instrument we designed (Attitudes to Gene Therapy-Eye (AGT-Eye)) and their associations with demographic data, self-reported visual status, and tools assessing quality of life and attitudes toward clinical trials using a community-based cross-sectional survey of Australian adults with IRD. AGT-Eye, overall quality of life EQ-5D-5L, National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) and Patient Attitudes to Clinical Trials (PACT-22) instruments were administered. Six hundred and eighty-one people completed the study, 51.7% women of mean age 53.5 years (SD ± 15.8). Most participants (91.6%) indicated they would likely accept gene therapy if it was available to them or family members. However, only 28.3% agreed that they had good knowledge of gene therapy. Most obtained information about gene therapy from the internet (49.3%). Respondents with post-graduate degrees scored highest compared to other educational levels on methods (p < 0.001) and outcomes (p = 0.003) and were more likely to see economic value of treatment (p = 0.043). Knowledge gaps were present regarding methods and outcomes of gene therapy. This survey has shown high level of interest in the IRD community for gene therapies, and highlights areas for improved clinician and patient education.

In Vitro and In Vivo Efficacy of NITD-916 against Mycobacterium fortuitum.

Mycobacterium fortuitum represents one of the most clinically relevant rapid-growing mycobacterial species. Treatments are complex due to antibiotic resistance and to severe side effects of effective drugs, prolonged time of treatment, and co-infection with other pathogens. Herein, we explored the activity of NITD-916, a direct inhibitor of the enoyl-ACP reductase InhA of the type II fatty acid synthase in Mycobacterium tuberculosis. We found that this compound displayed very low MIC values against a panel of M. fortuitum clinical strains and exerted potent antimicrobial activity against M. fortuitum in macrophages. Remarkably, the compound was also highly efficacious in a zebrafish model of infection. Short duration treatments were sufficient to significantly protect the infected larvae from M. fortuitum-induced killing, which correlated with reduced bacterial burdens and abscesses. Biochemical analyses demonstrated an inhibition of de novo synthesis of mycolic acids. Resolving the crystal structure of the InhAMFO in complex with NAD and NITD-916 confirmed that NITD-916 is a direct inhibitor of InhAMFO. Importantly, single nucleotide polymorphism leading to a G96S substitution in InhAMFO conferred high resistance levels to NITD-916, thus resolving its target in M. fortuitum. Overall, these findings indicate that NITD-916 is highly active against M. fortuitum both in vitro and in vivo and should be considered in future preclinical evaluations for the treatment of M. fortuitum pulmonary diseases.

Collaborative Team Training in Virtual Reality is Superior to Individual Learning For Performing Complex Open Surgery: A Randomized Controlled Trial.

OBJECTIVE: To assess whether multiplayer immersive Virtual Reality (iVR) training was superior to single-player training for the acquisition of both technical and nontechnical skills in learning complex surgery. BACKGROUND: Superior teamwork in the operating room (OR) is associated with improved technical performance and clinical outcomes. iVR can successfully train OR staff individually; however, iVR team training has yet to be investigated. METHODS: Forty participants were randomized to individual or team iVR training. Individually trained participants practiced alongside virtual avatar counterparts, whereas teams trained live in pairs. Both groups underwent 5 iVR training sessions over 6 weeks. Subsequently, they completed a real-life assessment in which they performed anterior approach total hip arthroplasty surgery on a high-fidelity model with real equipment in a simulated OR. Teams performed together, and individually trained participants were randomly paired up. Videos were marked by 2 blinded assessors recording the 'Non-Operative Technical Skills for Surgeons, Oxford NOn-TECHnical Skills II and Scrub Practitioners' List of Intraoperative Non-Technical Skills' scores. Secondary outcomes were procedure duration and the number of technical errors. RESULTS: Teams outperformed individually trained participants for nontechnical skills in the real-world assessment (Non-Operative Technical Skills for Surgeons: 13.1±1.5 vs 10.6±1.6, P = 0.002, Non-TECHnical Skills II score: 51.7 ± 5.5 vs 42.3 ± 5.6, P = 0.001 and Scrub Practitioners' List of Intraoperative Non-Technical Skills: 10 ± 1.2 vs 7.9 ± 1.6, P = 0.004). They completed the assessment 33% faster (28.2 minutes ± 5.5 vs 41.8 ± 8.9, P < 0.001), and made fewer than half the number of technical errors (10.4 ± 6.1 vs 22.6 ± 5.4, P < 0.001). CONCLUSIONS: Multiplayer training leads to faster surgery with fewer technical errors and the development of superior nontechnical skills.

Aconitate decarboxylase 1 participates in the control of pulmonary Brucella infection in mice.

Brucellosis is one of the most widespread bacterial zoonoses worldwide. Here, our aim was to identify the effector mechanisms controlling the early stages of intranasal infection with Brucella in C57BL/6 mice. During the first 48 hours of infection, alveolar macrophages (AMs) are the main cells infected in the lungs. Using RNA sequencing, we identified the aconitate decarboxylase 1 gene (Acod1; also known as Immune responsive gene 1), as one of the genes most upregulated in murine AMs in response to B. melitensis infection at 24 hours post-infection. Upregulation of Acod1 was confirmed by RT-qPCR in lungs infected with B. melitensis and B. abortus. We observed that Acod1-/- C57BL/6 mice display a higher bacterial load in their lungs than wild-type (wt) mice following B. melitensis or B. abortus infection, demonstrating that Acod1 participates in the control of pulmonary Brucella infection. The ACOD1 enzyme is mostly produced in mitochondria of macrophages, and converts cis-aconitate, a metabolite in the Krebs cycle, into itaconate. Dimethyl itaconate (DMI), a chemically-modified membrane permeable form of itaconate, has a dose-dependent inhibitory effect on Brucella growth in vitro. Interestingly, structural analysis suggests the binding of itaconate into the binding site of B. abortus isocitrate lyase. DMI does not inhibit multiplication of the isocitrate lyase deletion mutant ΔaceA B. abortus in vitro. Finally, we observed that, unlike the wt strain, the ΔaceA B. abortus strain multiplies similarly in wt and Acod1-/- C57BL/6 mice. These data suggest that bacterial isocitrate lyase might be a target of itaconate in AMs.

A systematic review and meta-analysis of the effect of obesity on patients undergoing lower extremity revascularization.

OBJECTIVE: In the present review, we assessed the effect of obesity on clinical outcomes for patients with peripheral arterial disease who had undergone endovascular or open lower extremity revascularization surgery. METHODS: A systematic search strategy of MEDLINE, EMBASE, CINAHL, Web of Science, and Cochrane Library was conducted. The included studies had compared obese and nonobese cohorts with peripheral arterial disease who had undergone endovascular or open lower extremity revascularization. The outcomes included mortality, major adverse cardiovascular events, major adverse limb events, surgical site infections, endovascular access site complications, and perioperative complications. RESULTS: Eight studies were included with 171,648 patients. The obese patients (body mass index ≥30 kg/m2) were more likely to be women, to have diabetes, and to have more cardiovascular comorbidities despite being younger. No association was found between obesity and peripheral arterial disease severity. Obesity was associated with an overall 22% decreased mortality risk after lower extremity revascularization (risk ratio [RR], 0.78; 95% confidence interval [CI], 0.71-0.85; P < .001; I2 = 0%; GRADE (grading of recommendations assessment, development, evaluation), very low quality). A subgroup analysis by intervention type showed similar findings (endovascular: RR, 0.79; 95% CI, 0.71-0.87; P < .001; I2 = 0%; open: RR, 0.70; 95% CI, 0.51-0.95; P = .024; I2 = 43%). Obesity was associated with a 14% decreased risk of major adverse cardiovascular events for open surgery only (RR, 0.86; 95% CI, 0.76-0.98; P = .021; I2 = 0%; GRADE, very low quality). Obesity was associated with an increased risk of surgical site infections pooled across intervention types (RR, 1.69; 95% CI, 1.34-2.14; P < .001; I2 = 78%; GRADE, very low quality). No association was found between obesity and major adverse limb events (RR, 1.02; 95% CI, 0.93-1.11; P = .73; I2 = 15%; GRADE, very low quality) or endovascular access site complications (RR, 1.11; 95% CI, 0.76-1.63; P = .58; I2 = 86%; GRADE, very low quality). Pooled perioperative complications did not differ between the obese and nonobese cohorts (RR, 1.04; 95% CI, 0.84-1.28; P = .73; I2 = 92%; GRADE, very low quality). CONCLUSIONS: Obesity was associated with reduced mortality risk with both endovascular and open surgery, although a reduction in major adverse cardiovascular events was only observed with open surgery. In addition, obese patients had an increased risk of surgical site infections. Obesity was not associated with major adverse limb events, endovascular access site complications, or perioperative complications. The GRADE quality of evidence was very low. The findings from the present review suggest a survival advantage for obese patients with peripheral arterial disease. Future studies could focus on prospectively investigating the effect of obesity on peripheral arterial disease outcomes. A nuanced evaluation of body mass index as a preoperative risk factor is warranted.

The MoXFo initiative - study design: Considerations related to study design and methodology in exercise research for people with multiple sclerosis.

BACKGROUND: Exercise as a subset of physical activity is a cornerstone in the management of multiple sclerosis (MS) based on its pleiotropic effects, but continued progression of the field requires better future designs and methodologies. OBJECTIVES: This paper outlines the work of the 'Study design and methodology' group of the MoXFo (moving exercise research forward) initiative, and addresses critical aspects and future directions when defining the research question of interest, and subsequently, designing the study and exercise intervention in MS patients. METHODS: The work is based on the formation of an international expert panel formed within the MoXFo initiative. We provide a structured and concise synthesis of exercise-specific MS research challenges and considerations when designing randomized controlled trials (RCTs). RESULTS: Challenges and considerations are presented using the Patient population, Intervention, Comparator, Outcomes, Timing, Setting (PICOTS) framework, thereby forming a new and specific MS exercise PICOTS framework. CONCLUSION: We propose that researchers should carefully consider and align all elements of this MS exercise PICOTS framework when developing future research questions and study designs, ultimately improving the quality of new exercise studies in people with MS.

Evaluation of eight lateral flow tests for the detection of anti-SARS-CoV-2 antibodies in a vaccinated population.

BACKGROUND: Rapid determination of an individual's antibody status can be beneficial in understanding an individual's immune response to SARS-CoV-2 and for initiation of therapies that are only deemed effective in sero-negative individuals. Antibody lateral flow tests (LFTs) have potential to address this need as a rapid, point of care test. METHODS: Here we present a proof-of-concept evaluation of eight LFT brands using sera from 95 vaccinated individuals to determine sensitivity for detecting vaccination generated antibodies. Samples were analysed on eight different brands of antibody LFT and an automated chemiluminescent microparticle immunoassay (CMIA) that identifies anti-spike antibodies which was used as our reference standard. RESULTS: All 95 (100%) participants tested positive for anti-spike antibodies by the chemiluminescent microparticle immunoassay (CMIA) reference standard post-dose two of their SARS-CoV-2 vaccine: BNT162b2 (Pfizer/BioNTech, n = 60), AZD1222 (AstraZeneca, n = 31), mRNA-1273 (Moderna, n = 2) and Undeclared Vaccine Brand (n = 2). Sensitivity increased from dose one to dose two in six out of eight LFTs with three tests achieving 100% sensitivity at dose two in detecting anti-spike antibodies. CONCLUSIONS: These tests are demonstrated to be highly sensitive to detect raised antibody levels in vaccinated individuals. RDTs are low cost and rapid alternatives to ELISA based systems.

Editorial Commentary: In Patients With Hip-Spine Syndrome, a Single Simple Solution May Not Apply: Occam's Razor Becomes Blunt.

The importance of hip-spine syndrome in a nonarthritic population, in which patients present with coexisting symptoms in both the hip and lumbar spine, is becoming more clear. Several studies have shown inferior outcomes in patients undergoing treatment for femoral acetabular impingement syndrome with coexisting spinal symptoms. The most important factor when treating HSS patients is understanding each patient's pathology. A history and physical examination with provocative tests for spinal and hip pathology often provide the answer. Routine standing and seated lateral radiographs are required to assess spinopelvic mobility. If the cause of pain is unclear, diagnostic intra-articular hip injections with local anesthetic and further imaging of the lumbar spine are recommended. In patients with degenerative spine disease with neural impingement, these symptoms may persist after hip arthroscopy, particularly if not improved by intra-articular injections. Patients should be appropriately counseled. If hip symptoms predominate, treatment of femoroacetabular impingement syndrome results in improved outcomes, even with coexisting neural impingement. If spine symptoms predominate, referral to an appropriate specialist may be required. In patients with HSS, Occam's razor becomes blunt; thus, a single simple solution may not apply, and we may need to consider treating each pathology separately.

Development of a CRISPRi Human Retinal Pigmented Epithelium Model for Functional Study of Age-Related Macular Degeneration Genes.

Age-related macular degeneration (AMD) is a blinding disease characterised by dysfunction of the retinal pigmented epithelium (RPE) which culminates in disruption or loss of the neurosensory retina. Genome-wide association studies have identified >60 genetic risk factors for AMD; however, the expression profile and functional role of many of these genes remain elusive in human RPE. To facilitate functional studies of AMD-associated genes, we developed a human RPE model with integrated CRISPR interference (CRISPRi) for gene repression by generating a stable ARPE19 cell line expressing dCas9-KRAB. We performed transcriptomic analysis of the human retina to prioritise AMD-associated genes and selected TMEM97 as a candidate gene for knockdown study. Using specific sgRNAs, we showed that knockdown of TMEM97 in ARPE19 reduced reactive oxygen species (ROS) levels and exerted a protective effect against oxidative stress-induced cell death. This work provides the first functional study of TMEM97 in RPE and supports a potential role of TMEM97 in AMD pathobiology. Our study highlights the potential for using CRISPRi to study AMD genetics, and the CRISPRi RPE platform generated here provided a useful in vitro tool for functional studies of AMD-associated genes.

Escaping the Silos: Utilization of a Pediatric Trauma Escape Room to Promote Interprofessional Education and Collaboration.

BACKGROUND: Millions of children are treated annually for trauma-related injuries but comprise a smaller proportion of emergency department visits than adults. As a result, emergency department teams may not have the knowledge, skills, and confidence to care for pediatric patients, and specialty teams may not interact enough as an interprofessional team to provide high-quality patient care. OBJECTIVE: The purpose of this project is to describe a novel interprofessional simulation-based education initiative to assist pediatric trauma team readiness. METHODS: An escape room was designed to provide an interactive educational environment focused on pediatric trauma education. Using an interprofessional dyad of a trauma nursing specialist and a pediatric nursing expert, the escape room was designed as a series of clues to improve pediatric skills and interprofessional collaboration between specialty teams. The escape room training was conducted (from February to March, 2023) in a large Southeastern U.S. Level II adult trauma center. RESULTS: Twenty-one registered nurses from different specialty teams participated in the simulation exercises with overwhelmingly positive feedback. Colleagues reported this was a unique way to deliver education that resulted in innovative team building and enriched collegiality between the specialty teams. CONCLUSIONS: The escape room educational format was positively received, and future events are planned across disciplines and various topics. Trauma centers with lower pediatric volumes seeking to provide engaging team-based education may use this format as a unique and innovative way to develop teams for clinical success.

Complications and early recovery following hip hemiarthroplasty through the direct anterior approach: a systematic review and meta-analysis.

PURPOSE: Minimizing complications is an important focus in hip hemiarthroplasty (HHA) for femoral neck fracture (FNF) patients given the associated high morbidity and mortality rates. This systematic review and meta-analysis aimed to compare the clinical and functional outcomes associated with the direct anterior approach (DAA) compared to other surgical approaches used for HHA. METHODS: Studies evaluating HHA-treated FNFs using the DAA were compared through meta-analysis to all other surgical approaches combined and as distinct subgroups. Outcomes included overall complication rate, mortality rate, dislocation rate, reoperation rate, periprosthetic fracture rate, infection rate, length of stay (LOS), mobility, perioperative blood loss, operative time, and postoperative pain. RESULTS: Nineteen studies met the inclusion criteria, totaling 2,018 HHAs. DAA significantly reduced the overall complication rate (odds ratio (OR) = 0.73, 95% confidence interval (CI) 0.57 to 0.94, p = 0.01), dislocation rate (OR = 0.34, 95% CI 0.15 to 0.77, p = 0.01), and LOS (mean difference (MD) = -1.31 days, 95% CI - 2.12 to - 0.50, p = 0.002). Findings from studies that were not appropriate for meta-analysis were qualitatively summarized and suggested improved mobility and reduced postoperative pain with the DAA. Significant differences were not detected in any of the remaining outcomes. CONCLUSION: The DAA HHA appears to be safer, reduces hospital stay, and may improve early functional recovery. This article supports the DAA HHA as a safe option for the management of displaced intracapsular FNFs.

A missense variant in specificity protein 6 (SP6) is associated with amelogenesis imperfecta.

Amelogenesis is the process of enamel formation. For amelogenesis to proceed, the cells of the inner enamel epithelium (IEE) must first proliferate and then differentiate into the enamel-producing ameloblasts. Amelogenesis imperfecta (AI) is a heterogeneous group of genetic conditions that result in defective or absent tooth enamel. We identified a 2 bp variant c.817_818GC>AA in SP6, the gene encoding the SP6 transcription factor, in a Caucasian family with autosomal dominant hypoplastic AI. The resulting missense protein change, p.(Ala273Lys), is predicted to alter a DNA-binding residue in the first of three zinc fingers. SP6 has been shown to be crucial to both proliferation of the IEE and to its differentiation into ameloblasts. SP6 has also been implicated as an AI candidate gene through its study in rodent models. We investigated the effect of the missense variant in SP6 (p.(Ala273Lys)) using surface plasmon resonance protein-DNA binding studies. We identified a potential SP6 binding motif in the AMBN proximal promoter sequence and showed that wild-type (WT) SP6 binds more strongly to it than the mutant protein. We hypothesize that SP6 variants may be a very rare cause of AI due to the critical roles of SP6 in development and that the relatively mild effect of the missense variant identified in this study is sufficient to affect amelogenesis causing AI, but not so severe as to be incompatible with life. We suggest that current AI cohorts, both with autosomal recessive and dominant disease, be screened for SP6 variants.

The safety and efficacy of gene therapy treatment for monogenic retinal and optic nerve diseases: A systematic review.

PURPOSE: This study aimed to systematically review and summarize gene therapy treatment for monogenic retinal and optic nerve diseases. METHODS: This review was prospectively registered (CRD42021229812). A comprehensive literature search was performed in Ovid MEDLINE, Ovid Embase, Cochrane Central, and clinical trial registries (February 2021). Clinical studies describing DNA-based gene therapy treatments for monogenic posterior ocular diseases were eligible for inclusion. Risk of bias evaluation was performed. Data synthesis was undertaken applying Synthesis Without Meta-analysis guidelines. RESULTS: This study identified 47 full-text publications, 50 conference abstracts, and 54 clinical trial registry entries describing DNA-based ocular gene therapy treatments for 16 different genetic variants. Study summaries and visual representations of safety and efficacy outcomes are presented for 20 unique full-text publications in RPE65-mediated retinal dystrophies, choroideremia, Leber hereditary optic neuropathy, rod-cone dystrophy, achromatopsia, and X-linked retinoschisis. The most common adverse events were related to lid/ocular surface/cornea abnormalities in subretinal gene therapy trials and anterior uveitis in intravitreal gene therapy trials. CONCLUSION: There is a high degree of variability in ocular monogenic gene therapy trials with respect to study design, statistical methodology, and reporting of safety and efficacy outcomes. This review improves the accessibility and transparency in interpreting gene therapy trials to date.