Knowledge, attitude and practices towards oral health among secondary school students in Huye district, Rwanda.

Background: Good oral health knowledge is considered to be crucial for health-related practices and better oral hygiene. Objective: This study was aimed to assess knowledge, attitudes and practices towards oral health among secondary student in Huye district. Methods: A cross-sectional survey was conducted with 386 students from public secondary schools with advanced level. Boarding secondary schools were excluded. Stratified Clustering sampling technique was used for selecting study participants. A closed ended questionnaire was used for collecting data. Results were found on the basis of percentage and frequency using SPSS 21.0 version. Results: The majority of participants, 222 (57.5%) were female and 164 (42.5%) were male. The majority of the participants, 168 (43.5%) were between 15-17 years old. Out of the total population of students 1.8% had good knowledge, 56.2% had average knowledge and 42% had poor knowledge about oral health. Moreover, 56.2% had negative and 43.8% had positive oral health attitudes and overall practice towards oral hygiene of students showed that 74.6 % had poor practice and 24.4% had good practices. Conclusion: Oral hygiene has to be long life practice and oral health education have to be included as part of the school environment.

Fazirsiran for Adults with Alpha-1 Antitrypsin Deficiency Liver Disease: A Phase 2 Placebo Controlled Trial (SEQUOIA).

BACKGROUND & AIMS: Homozygous ZZ alpha-1 antitrypsin (AAT) deficiency produces mutant AAT (Z-AAT) proteins in hepatocytes, leading to progressive liver fibrosis. We evaluated the safety and efficacy of an investigational RNA interference therapeutic, fazirsiran, that degrades Z-AAT mRNA, reducing deleterious protein synthesis. METHODS: This ongoing, phase 2 study randomized 40 patients to subcutaneous placebo or fazirsiran 25/100/200 mg. The primary endpoint was percentage change in serum Z-AAT concentration from baseline to Week 16. Patients with fibrosis on baseline liver biopsy received treatment on Day 1, Week 4, and then every 12 weeks, and had a second liver biopsy at or after Weeks 48, 72, or 96. Patients without fibrosis received two doses on Day 1 and Week 4. RESULTS: At Week 16, least-squares mean percent declines in serum Z-AAT concentration were -61%, -83% and -94% with fazirsiran 25/100/200 mg, respectively, versus placebo (all P< .0001). Efficacy was sustained through Week 52. At post-dose liver biopsy, fazirsiran reduced median liver Z-AAT concentration by 93% compared with an increase of 26% with placebo. All fazirsiran-treated patients had histological reduction from baseline in hepatic globule burden. Portal inflammation improved in 5/12 and 0/8 patients with baseline score >0 in the fazirsiran and placebo groups, respectively. Histological METAVIR score improved by >1 point in 7/14 and 3/8 patients with fibrosis >F0 at baseline in the fazirsiran and placebo groups, respectively. No adverse events led to discontinuation and pulmonary function tests remained stable. CONCLUSIONS: Fazirsiran reduced serum and liver concentrations of Z-AAT in a dose dependent manner and reduced hepatic globule burden (NCT03945292).

Yao syndrome: a novel systemic autoinflammatory disease with cutaneous manifestations.

Yao syndrome (YAOS) is a novel systemic autoinflammatory disease linked to the nucleotide-binding oligomerization domain (NOD2) gene. It is characterized by periodic fevers, gastrointestinal (GI) symptoms, arthritis, and dermatitis, among other symptoms. A sparse literature exists on this disease, and little is known about its dermatological manifestations. A review of available literature was performed to characterize the cutaneous manifestations of Yao syndrome. Cutaneous manifestations were documented in 85.7% of patients, with common characteristic descriptions of erythematous patches and plaques involving the face, trunk, abdomen, and extremities. Based on our review of treatment modalities employed for Yao syndrome, prednisone is an appropriate initial approach, with oral sulfasalazine and other disease-modifying antirheumatic drugs serving as appropriate secondary options. YAOS should be considered in the differential diagnosis of patients presenting with a dermatitic rash, especially in the context of concurrent articular symptoms, periodic fever, and GI symptoms.

Changes in primary care visits for respiratory illness during the COVID-19 pandemic: a multinational study by the International Consortium of Primary Care Big Data Researchers (INTRePID).

Objectives: The majority of patients with respiratory illness are seen in primary care settings. Given COVID-19 is predominantly a respiratory illness, the INTernational ConsoRtium of Primary Care BIg Data Researchers (INTRePID), assessed the pandemic impact on primary care visits for respiratory illnesses. Design: Definitions for respiratory illness types were agreed on collectively. Monthly visit counts with diagnosis were shared centrally for analysis. Setting: Primary care settings in Argentina, Australia, Canada, China, Norway, Peru, Singapore, Sweden and the United States. Participants: Over 38 million patients seen in primary care settings in INTRePID countries before and during the pandemic, from January 1st, 2018, to December 31st, 2021. Main outcome measures: Relative change in the monthly mean number of visits before and after the onset of the pandemic for acute infectious respiratory disease visits including influenza, upper and lower respiratory tract infections and chronic respiratory disease visits including asthma, chronic obstructive pulmonary disease, respiratory allergies, and other respiratory diseases. Results: INTRePID countries reported a marked decrease in the average monthly visits for respiratory illness. Changes in visits varied from -10.9% [95% confidence interval (CI): -33.1 to +11.3%] in Norway to -79.9% (95% CI: -86.4% to -73.4%) in China for acute infectious respiratory disease visits and - 2.1% (95% CI: -12.1 to +7.8%) in Peru to -59.9% (95% CI: -68.6% to -51.3%) in China for chronic respiratory illness visits. While seasonal variation in allergic respiratory illness continued during the pandemic, there was essentially no spike in influenza illness during the first 2 years of the pandemic. Conclusion: The COVID-19 pandemic had a major impact on primary care visits for respiratory presentations. Primary care continued to provide services for respiratory illness, although there was a decrease in infectious illness during the COVID pandemic. Understanding the role of primary care may provide valuable information for COVID-19 recovery efforts and planning for future global emergencies.

The Public Health Leader Who Brought Antisepsis to William Halsted.

William Halsted wrote to aging surgeon, Stephen Smith, in 1919, that he remembered the lessons Smith had taught him, "when I walked with you through the wards of Bellevue Hospital." Smith was an early advocate of Joseph Lister's antiseptic method, and because of his public health work, he was also an early advocate of environmental hygiene and microbial control based on the unproved germ theory. While Lister's work at the time emphasized germ-killing around the operative site with carbolic acid (antisepsis), Smith adopted and encouraged surgical practices at Bellevue that would be hallmarks of the germ-preventing (asepsis) surgical approach that fully developed after German bacteriologic discoveries in the mid-1880s, and with which Halsted is historically identified. Some physicians and historians have emphasized temporal and conceptual differences between Lister's antisepsis and German asepsis, but Smith and Halsted's experiences argue that surgical asepsis was the evolutionary outcome of germ theory-based surgical changes that began well before scientific proof arrived.

Broadening The Substrate Scope of Aldolases Through Metagenomic Enzyme Discovery.

Bio-processes based on enzymatic catalysis play a major role in the development of green, sustainable processes, and the discovery of new enzymes is key to this approach. In this work, we analysed ten metagenomes and retrieved 48 genes coding for deoxyribose-5-phosphate aldolases (DERAs, EC 4.1.2.4) using a sequence-based approach. These sequences were recombinantly expressed in Escherichia coli and screened for activity towards a range of aldol additions. Among these, one enzyme, DERA-61, proved to be particularly interesting and catalysed the aldol addition of furfural or benzaldehyde with acetone, butanone and cyclobutanone with unprecedented activity. The product of these reactions, aldols, can find applications as building blocks in the synthesis of biologically active compounds. Screening was carried out to identify optimized reaction conditions targeting temperature, pH, and salt concentrations. Lastly, the kinetics and the stereochemistry of the products were investigated, revealing that DERA-61 and other metagenomic DERAs have superior activity and stereoselectivity when they are provided with non-natural substrates, compared to well-known DERAs.

Surgical Strategy for Dumbbell-Shaped Cervical Schwannoma at the Vicinity of the Vertebral Artery: The Utilization of Anatomic Layer.

BACKGROUND AND OBJECTIVES: In cases where dumbbell-shaped cervical schwannoma encases the vertebral artery (VA), there is a risk of VA injury during surgery. The objective of this study is to propose a strategy for preserving the VA during the surgical excision of tumors adjacent to the VA through the utilization of anatomic layers. METHODS: A retrospective analysis was conducted on 37 patients who underwent surgery for dumbbell-shaped cervical schwannoma with contacting VA from January 2004 to July 2023. The VA encasement group consisted of 12 patients, and the VA nonencasement group included 25 patients. RESULTS: The perineurium acted as a protective barrier from direct VA exposure or injury during surgery. However, in the VA encasement group, 1 patient was unable to preserve the perineurium while removing a tumor adjacent to the VA, resulting in VA injury. The patient had the intact dominant VA on the opposite side, and there were no new neurological deficits or infarctions after the surgery. Gross total resection was achieved in 25 patients (67.6%), while residual tumor was confirmed in 12 patients (32.4%). Four patients (33.3% of 12 patients) underwent reoperation because of the regrowth of the residual tumor within the neural foramen. In the case of the 8 patients (66.7% of 12 patients) whose residual tumor was located outside the neural foramen, no regrowth was observed, and there was no recurrence of the tumor within the remaining perineurium after total resection. CONCLUSION: In conclusion, when resecting a dumbbell-shaped cervical schwannoma contacting VA, subperineurium dissection prevents VA injury because the perineurium acts as a protective barrier.

A Long-Term Safety and Tolerability Study of TV-46000 for Subcutaneous Use in Patients with Schizophrenia: A Phase 3, Randomized, Double-Blinded Clinical Trial.

BACKGROUND: TV-46000 is a long-acting subcutaneous antipsychotic (LASCA) formulation of risperidone that is approved by the United States Food and Drug Administration for the treatment of schizophrenia in adults. In the phase 3, randomized, double-blind RIsperidone Subcutaneous Extended-release (RISE) study, TV-46000 once monthly (q1m) and once every 2 months (q2m) significantly prolonged time to impending relapse compared with placebo [5.0-fold (q1m) and 2.7-fold (q2m)]. This phase 3, randomized, double-blind Safety in Humans of TV-46000 subcutaneous INjection Evaluation (SHINE) study was designed to evaluate the long-term safety, tolerability, and exposure of TV-46000 in schizophrenia. METHODS: Patients who completed RISE without relapse (rollover) or who were newly recruited (de novo) were eligible for the SHINE study. Patients were initially stabilized on oral risperidone for 12 weeks (completed in RISE for rollover, or in SHINE for de novo). Patients in the de novo cohort and patients who received placebo in RISE were randomized 1:1 in SHINE to receive TV-46000 q1m or q2m for up to 56 weeks. Primary endpoint for SHINE was frequency of reported adverse events (AEs); event rates [ER; events per 100 patient-years (PYs)] were calculated for each AE by patients upon general questioning. RESULTS: Overall, 336 patients were randomized in SHINE [TV-46000 q1m, n = 174; TV-46000 q2m, n = 162; of these, de novo, n = 109 and rollover, n = 227 (n = 172 patients were treated and n = 55 received placebo)]. A total of 334 patients were evaluated for safety [q1m, n = 172 (PY = 97.8); q2m, n = 162 (PY = 104.5)]. Proportions of patients (ER) with ≥ 1 AE and ≥ 1 treatment-related AE were 37% (180.0) and 21% (84.9) for TV-46000 q1m and 46% (157.9) and 20% (70.8) for TV-46000 q2m, respectively. Frequent treatment-related AEs [≥ 3% of patients in either group; proportion of patients (ER)] were injection site pain [q1m, 5% (24.5); q2m, 4% (22.0)] and injection site nodule [q1m, 2% (9.2); q2m, 6% (12.4)]. The proportions of patients with serious AEs was 5% for TV-46000 q1m and 7% for TV-46000 q2m; serious AEs reported for ≥ 2 patients overall were worsening schizophrenia [q1m, n = 1 (< 1%; ER, 1.02); q2m, n = 2 (1%; ER, 1.91)] and hyperglycemia [q1m, n = 1 (< 1%; ER, 1.02); q2m, n = 1 (< 1%; ER, 0.96)]. Of three reported deaths, none were related to treatment. Overall, eight patients discontinued treatment because of AEs. Similar or somewhat lower rates of AEs were reported for patients who rolled over from TV-46000 treatment compared with those who had no prior TV-46000 treatment (de novo and placebo rollover). Most AEs related to injection site reactions were mild; no patient had a severe reaction. CONCLUSION: Results from this long-term safety study add to the favorable safety profiles of TV-46000 q1m and q2m, consistent with other formulations of risperidone and previous studies with TV-46000. REGISTRATION: ClinicalTrials.gov, NCT03893825; 27 March 2019.

The United States Food and Drug Administration approved TV-46000 in April 2023 for the treatment of schizophrenia in adults. TV-46000 is a long-acting subcutaneous antipsychotic (LASCA) that uses technology that allows for the slow release of risperidone. TV-46000 is injected under the skin once monthly or once every 2 months. When people start taking TV-46000, they do not need an additional injection or oral risperidone. The Safety in Humans of TV-46000 subcutaneous INjection Evaluation (SHINE) was a clinical study in which patients with schizophrenia received TV-46000. SHINE was conducted in patients who completed the RIsperidone Subcutaneous Extended-release (RISE) study and new patients. All patients (TV-46000 once monthly, n = 162; TV-46000 once every 2 months, n = 172) received TV-46000 in SHINE to see whether safety results were the same long term compared with RISE. The proportions with more than one adverse event were 37% for TV-46000 once monthly and 46% for TV-46000 once every 2 months. The proportions with more than one adverse event related to treatment were 21% for TV-46000 once monthly and 20% for TV-46000 once every 2 months. Common adverse events related to treatment were injection site pain and small swelling. Serious adverse events were rare. None of the three reported deaths were related to treatment. Similar or lower rates of adverse events were reported for those who received TV-46000 in RISE compared with those with no prior TV-46000 treatment. The long-term safety results in SHINE were consistent with other forms of risperidone and previous studies with TV-46000.

Development and Evaluation of a Community Advisory Board for Family Violence.

Although intimate partner violence (IPV) is an important risk factor for child physical abuse, most IPV-exposed children are not evaluated for abusive injuries. A Community Advisory Board (CAB) was formed to (a) optimize a program to evaluate IPV-exposed children for abusive injuries and (b) inform research methods to engage IPV victims and their children. The objectives of this study were to implement and to evaluate the family violence CAB. Following best practices on CAB formation, we recruited local stakeholders with key roles as service providers, community leaders, and knowledge experts in IPV, child abuse, and emergency care. Fourteen members met bimonthly to develop a family-centered intervention and to inform research and advocacy activities. A shared memorandum of understanding outlined goals and objectives. One year after the CAB's implementation, a research assistant interviewed CAB members to understand their experiences, perceived benefits of participation, and desired improvements. Eleven CAB members, including an IPV survivor, participated. Emerging categories included (a) motivations to join the CAB (victim advocacy), (b) benefits of participation (development of relationships among members and increased acceptability of research methods), (c) facilitators of sustainability (program adaptability and development of trust), and (d) desired improvements (case-based follow-up). The CAB was successfully implemented and facilitated the development of collaborative relationships among stakeholders with key roles in IPV and child abuse. The CAB led to community member-proposed changes in research activities and clinical care for victims of IPV.

Asking the "Right" Questions about Financial Hardship: Using Cognitive Interviews with Adolescents and Young Adults with Cancer and Their Caregivers to Inform Measure Development.

Purpose: Financial hardship as a result of cancer treatment can have a significant and lasting negative impact on adolescents and young adults (AYAs) and their families. To address a lack of developmentally informed and psychometrically sound measures of financial hardship for AYAs and their caregivers, we used rigorous measurement development methods recommended by the National Institutes of Health's Patient-Reported Outcomes Measurement Information System® (PROMIS®) to determine comprehensibility and relevance of measure content. Methods: Our multi-step approach involved item identification, refinement, and generation; translatability and reading level review; and cognitive interviews. A purposive sample of 25 AYAs and 10 caregivers participated, ensuring representation across age, education, gender, race/ethnicity, and cancer type. Results: Fifty patient-reported and caregiver-reported items were developed across material, psychosocial, and behavioral subdomains of financial hardship. Translatability and reading level reviews resulted in 22 patient-reported and 25 caregiver-reported items being rewritten. Eighty-eight percent of patients and all caregivers described the items as easy to answer. Younger AYAs (15 to 25 years of age) were more likely to say the items were less relevant for them. Forty-six patient-reported and 48 caregiver-reported items were recommended for further testing. Conclusion: This study is the first to use in-depth qualitative methods to center AYA patient and caregiver experiences in the creation of new measures of financial hardship. Data support the comprehensibility and content validity of these preliminary item banks. Future large-scale, quantitative testing will lead to additional refinements and support the use of short forms and computer-adaptive testing for a diverse sample of AYAs and their caregivers.

Density functional theory and enzyme studies support interactions between angiotensin receptor blockers and angiotensin converting enzyme-2: Relevance to coronavirus 2019.

The binding affinities and interactions between eight drug candidates, both commercially available (candesartan; losartan; losartan carboxylic acid; nirmatrelvir; telmisartan) and newly synthesized benzimidazole-N-biphenyltetrazole (ACC519T), benzimidazole bis-N,N'-biphenyltetrazole (ACC519T(2) and 4-butyl-N,N-bis([2-(2H-tetrazol-5-yl)biphenyl-4-yl]) methyl (BV6), and the active site of angiotensin-converting enzyme-2 (ACE2) were evaluated for their potential as inhibitors against SARS-CoV-2 and regulators of ACE2 function through Density Functional Theory methodology and enzyme activity assays, respectively. Notably, telmisartan and ACC519T(2) exhibited pronounced binding affinities, forming strong interactions with ACE2's active center, favorably accepting proton from the guanidinium group of arginine273. The ordering of candidates by binding affinity and reactivity descriptors, emerged as telmisartan > ACC519T(2) > candesartan > ACC519T > losartan carboxylic acid > BV6 > losartan > nirmatrelvir. Proton transfers among the active center amino acids revealed their interconnectedness, highlighting a chain-like proton transfer involving tyrosine, phenylalanine, and histidine. Furthermore, these candidates revealed their potential antiviral abilities by influencing proton transfer within the ACE2 active site. Furthermore, through an in vitro pharmacological assays we determined that candesartan and the BV6 derivative, 4-butyl-N,N0-bis[20-2Htetrazol-5-yl)bipheyl-4-yl]methyl)imidazolium bromide (BV6(K+)2) also contain the capacity to increase ACE2 functional activity. This comprehensive analysis collectively underscores the promise of these compounds as potential therapeutic agents against SARS-CoV-2 by targeting crucial protein interactions.

Double Aortic Arch: A Comparison of Fetal CMR, Postnatal CT and Surgical Findings.

BACKGROUND: In double aortic arch (DAA) one of the arches can demonstrate atretic portions postnatally, leading to diagnostic uncertainty due to overlap with isolated right aortic arch (RAA) variants. The main objective of this study is to demonstrate the morphological evolution of different DAA phenotypes from prenatal to postnatal life using 3D fetal cardiac magnetic resonance imaging (CMR) and postnatal CT/CMR imaging. METHODS: 3D fetal CMR was undertaken in fetuses with suspected DAA over a six-year period (Jan 2016 - Jan 2022). All cases with surgical confirmation of DAA were retrospectively studied and morphology on fetal CMR was compared to postnatal CT/CMR and surgical findings. RESULTS: 32 fetuses with surgically confirmed DAA underwent fetal CMR. All demonstrated a complete DAA with left-sided arterial duct. The RAA was dominant in 30/32 (94%). Postnatal CT/CMR was undertaken at median age of 3.3months (IQR 2.0-3.9) demonstrating DAA with patency of both arches in 9/32 (28%), with 6 showing signs of coarctation of the left aortic arch (LAA). The LAA isthmus was not present on CT/CMR in 22/32(69%), the transverse arch between left carotid and left subclavian artery was not present in 1 case. CONCLUSIONS: Fetal CMR provides novel insights into perinatal evolution of DAA. The smaller LAA can develop coarctation or atresia related to postnatal constriction of the arterial duct, making diagnosis of DAA challenging with contrast-enhanced CT/CMR. This highlights the potentially important role for prenatal 3D vascular imaging and might improve intepretation of postnatal imaging.

Ophthalmic drop waste due to self-imposed use cessation dates.

Self-imposed use cessation dates for multi-use eye drop bottles lead to significant drug waste and increased costs. We quantified the residual medication in eye drop bottles across three clinics in an academic ambulatory setting.

SHP2 as a primordial epigenetic enzyme expunges histone H3 pTyr-54 to amend androgen receptor homeostasis.

Mutations that decrease or increase the activity of the tyrosine phosphatase, SHP2 (encoded by PTPN11), promotes developmental disorders and several malignancies by varying phosphatase activity. We uncovered that SHP2 is a distinct class of an epigenetic enzyme; upon phosphorylation by the kinase ACK1/TNK2, pSHP2 was escorted by androgen receptor (AR) to chromatin, erasing hitherto unidentified pY54-H3 (phosphorylation of histones H3 at Tyr54) epigenetic marks to trigger a transcriptional program of AR. Noonan Syndrome with Multiple Lentigines (NSML) patients, SHP2 knock-in mice, and ACK1 knockout mice presented dramatic increase in pY54-H3, leading to loss of AR transcriptome. In contrast, prostate tumors with high pSHP2 and pACK1 activity exhibited progressive downregulation of pY54-H3 levels and higher AR expression that correlated with disease severity. Overall, pSHP2/pY54-H3 signaling acts as a sentinel of AR homeostasis, explaining not only growth retardation, genital abnormalities and infertility among NSML patients, but also significant AR upregulation in prostate cancer patients.

Rational protein engineering to enhance MHC-independent T cell receptors.

Chimeric antigen receptor (CAR)-based therapies have pioneered synthetic cellular immunity but remain limited in their long-term efficacy. Emerging data suggest that dysregulated CAR-driven T cell activation causes T cell dysfunction and therapeutic failure. To re-engage the precision of the endogenous T cell response, we designed MHC-independent T cell receptors (miTCRs) by linking antibody variable domains to TCR constant chains. Using predictive modeling, we observed that this standard "cut and paste" approach to synthetic protein design resulted in myriad biochemical conflicts at the hybrid variable-constant domain interface. Through iterative modeling and sequence modifications we developed structure-enhanced miTCRs which significantly improved receptor-driven T cell function across multiple tumor models. We found that 41BB costimulation specifically prolonged miTCR T cell persistence and enabled improved leukemic control in vivo compared to classic CAR T cells. Collectively, we have identified core features of hybrid receptor structure responsible for regulating function.

Torpor use in the wild by one of the world's largest bats.

Torpor is widespread among bats presumably because most species are small, and torpor greatly reduces their high mass-specific resting energy expenditure, especially in the cold. Torpor has not been recorded in any bat species larger than 50 g, yet in theory could be beneficial even in the world's largest bats (flying-foxes; Pteropus spp.) that are exposed to adverse environmental conditions causing energy bottlenecks. We used temperature telemetry to measure body temperature in wild-living adult male grey-headed flying-foxes (P. poliocephalus; 799 g) during winter in southern Australia. We found that all individuals used torpor while day-roosting, with minimum body temperature reaching 27°C. Torpor was recorded following a period of cool, wet and windy weather, and on a day with the coldest maximum air temperature, suggesting it is an adaptation to reduce energy expenditure during periods of increased thermoregulatory costs and depleted body energy stores. A capacity for torpor among flying-foxes has implications for understanding their distribution, behavioural ecology and life history. Furthermore, our discovery increases the body mass of bats known to use torpor by more than tenfold and extends the documented use of this energy-saving strategy under wild conditions to all bat superfamilies, with implications for the evolutionary maintenance of torpor among bats and other mammals.

Patient-specific Implants Improve Volumetric Surgical Accuracy Compared to Stock Reconstruction Plates in Modern Pardigm Virtual Surgical Planning of Fibular Free Flaps for Head and Neck Reconstruction.

BACKGROUND: Virtual surgical planning (VSP) for composite microvascular free flaps has become standard of care for oncologic head and neck reconstruction. Controversy remains as to the use of three-dimensional (3D)-printed titanium patient-specific implants (PSIs) versus hand-bent stock reconstruction plates. Proponents of PSIs cite improved surgical accuracy, reduced operative times, and improved clinical outcomes. Detractors purport increased cost associated with PSIs and presumed equivalent accuracy with less expensive stock plates. PURPOSE: The study purpose was to measure and compare the 3D-volumetric accuracy of PSI versus stock reconstruction plates among subjects undergoing VSP-guided mandibular fibular free flap reconstruction. STUDY DESIGN, SETTING, SAMPLE: A retrospective cohort study of subjects undergoing VSP-guided fibular free flap reconstructions at Mayo Clinic between 2016 and 2023 was performed. Subjects were excluded for non-VSP guidance, midfacial reconstruction, nonfibular free flaps, and lack of requisite study variables. PREDICTOR VARIABLE: The primary predictor was the type of reconstruction plate utilized (PSI vs stock plate). MAIN OUTCOME VARIABLE: The main outcome was volumetric surgical accuracy of the final reconstruction compared to the preoperative surgical plan by root mean square error (RMSE) calculation. Lower RMSE values indicated a higher surgical accuracy. COVARIATES: Covariates included age, sex, race, smoking status, American Society of Anesthesiologists Physical Status Classification System, Charlson Comorbidity Index, preoperative diagnosis, and number of fibular segments. ANALYSES: Differences in surgical accuracy were assessed between preoperative and postoperative segmented scans using volumetric overlays from which RMSE values were calculated. Univariate and multivariate modeling of plate type to RMSE calculation was performed. Statistical significance set to P < .05. RESULTS: Total of 130 subjects were identified, 105 PSI and 25 stock plates. Calculated mean RMSE in millimeters (mm) for stock plates was 1.46 (standard deviation: 0.33) and 1.15 (standard deviation: 0.36) for PSIs. Univariate modeling demonstrated a statistically significant difference in RMSE of 0.31 (95% confidence interval: 0.16-0.47) (P < .001) equating to a 21.2% (P < .001) improved volumetric surgical accuracy for PSIs. The association of improved volumetric accuracy with PSIs has been maintained in all multivariate models controlling for confounding. CONCLUSION AND RELEVANCE: In modern era VSP-guided head and neck fibular free flap reconstruction, patient-specific 3D-printed titanium implants confer a statistically significant improvement in volumetric surgical accuracy over stock reconstruction plates.

Spatial transcriptomics implicates impaired BMP signaling in NF1 fracture pseudarthrosis in murine and patient tissues.

The Neurofibromatosis Type 1 (NF1) RASopathy is associated with persistent fibrotic nonunions (pseudarthrosis) in human and mouse skeletal tissue. Here, we first performed spatial transcriptomics to define the molecular signatures across normal endochondral healing following fracture in mice. Within the control fracture callus, we observed spatially restricted activation of morphogenetic pathways, such as TGF-ß, WNT, and BMP. To investigate the molecular mechanisms contributing to Nf1-deficient delayed fracture healing, we performed spatial transcriptomic analysis on a Postn-cre;Nf1flox/- (Nf1Postn) fracture callus. Transcriptional analyses, subsequently confirmed through p-SMAD1/5/8 immunohistochemistry, demonstrated a lack of BMP pathway induction in Nf1Postn mice. To further inform the human disease, we performed spatial transcriptomic analysis of fracture pseudarthrosis tissue from a NF1 patient. Analyses detected increased MAPK signaling at the fibrocartilaginous-osseus junction. Similar to the Nf1Postn fracture, BMP pathway activation was absent within the pseudarthrosis tissue. Our results demonstrate the feasibility to delineate the molecular and tissue-specific heterogeneity inherent in complex regenerative processes, such as fracture healing, and to reconstruct phase transitions representing endochondral bone formation in vivo. Furthermore, our results provide in situ molecular evidence of impaired BMP signaling underlying NF1 pseudarthrosis, potentially informing the clinical relevance of off-label BMP2 as a therapeutic intervention.