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1.
Oecologia ; 2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39097560

RESUMEN

Organismal invasions have repeatedly been cited as a driving force behind the loss of biodiversity. Unlike many other impacts of invasion, the effect of invasion on native symbiont communities has received less attention. The introduction of invasive hosts presents a potential opportunity to native symbionts; invasive hosts could benefit native symbionts through providing a novel host environment that improves symbiont fitness relative to their fitness on native hosts. Alternatively, invasive hosts could noncompetent hosts for native symbionts, resulting in negative impacts on native symbiont abundance and diversity. Crayfish in the northern hemisphere host diverse assemblages of obligate annelid symbionts (P: Anellida, O: Branchiobdellida). Two invasive crayfish hosts in the genus Faxonius have been introduced and are interacting with the native crayfish hosts and their symbionts in three watersheds in western Virginia, USA. Previous studies suggest that the invasive host F. cristavarius is a less competent host for symbionts compared to native hosts in the genus Cambarus. We carried out an extensive survey in these watersheds to determine impacts of varying degrees of invasion on branchiobdellidan abundance and diversity. We also conducted a complementary host replacement experiment to investigate how increases in the relative abundance of invasive hosts contributes to observed patterns of symbiont abundance and diversity in the field. In our survey, as the proportion of invasive hosts at a site increased, branchiobdellidan abundance and diversity declined significantly. In the experiment, the worms dispersed onto both native and invasive hosts. As the percentage of noncompetent F. cristavarius hosts increased, the survival of branchiobdellidans declined. Both symbiont survival and opportunities for successful dispersal are reduced as this noncompetent invasive host progressively displaces native hosts, which imperils the integrity of native host-symbiont systems. Given that many native hosts accrue significant fitness benefits from their relationships with native symbionts, including hosts in our study system, losses of beneficial symbionts may produce a positive feedback loop that decreases invasion resistance of native species, exacerbates the effects of invasions, and presents a major conservation issue in invaded systems.

2.
Med Sci Educ ; 34(1): 71-76, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38510392

RESUMEN

An escape room is a team-based activity that requires players to solve a series of puzzles to complete a story and "break out" of a room. It has recently gained traction in medical education for its ability to interactively and effectively present learning objectives. This was a prospective educational study that describes the successful application of a nephrology themed escape room for first- and second-year medical students. Compared to pre-escape room participation, the 52 students demonstrated a statistically significant improvement in self-reported knowledge for renal physiology (p < 0.01), pharmacology (p < 0.01), pathology (p < 0.01), and relevant clinical practice guidelines (p < 0.01). A majority of the students also claimed that the escape room was "more effective" than traditional lectures (80.8%) and textbooks (73.1%) and "equally effective" as third-party board preparation resources (69.2%) and their institution's problem-based learning curriculum (51.9%). The escape room also facilitated a high-level peer-to-peer collaboration with 82.7% and 76.9% of students reporting that they worked with someone in their year and outside of their year for at least half of the game, respectively. Ninety-five percent of the first-years and 84.6% of the second-years believed that the escape room was effective at preparing them for their respective exams, and an overwhelming majority (90.4%) described the escape room as "very enjoyable." Overall, this nephrology themed escape room was an engaging and well received educational modality and may be an effective supplemental study resource for medical students. Further studies are needed to assess knowledge acquisition. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-023-01917-6.

3.
Tissue Eng Part A ; 30(1-2): 84-93, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37917102

RESUMEN

Background: The ability to reinnervate a muscle in the absence of a viable nerve stump is a challenging clinical scenario. Direct muscle neurotization (DMN) is an approach to overcome this obstacle; however, success depends on the formation of new muscle endplates, a process, which is often limited due to lack of appropriate axonal pathfinding cues. Objective: This study explored the use of a porcine nerve extracellular matrix hydrogel as a neuroinductive interface between nerve and muscle in a rat DMN model. The goal of the study was to establish whether such hydrogel can be used to improve neuromuscular function in this model. Materials and Methods: A common peroneal nerve-to-gastrocnemius model of DMN was developed. Animals were survived for 2 or 8 weeks following DMN with or without the addition of the hydrogel at the site of neurotization. Longitudinal postural thrust, terminal electrophysiology, and muscle weight assessments were performed to qualify and quantify neuromuscular function. Histological assessments were made to qualify the host response at the DMN site, and to quantify neuromuscular junctions (NMJs) and muscle fiber diameter. Results: The hydrogel-treated group showed a 132% increase in postural thrust at 8 weeks compared with that of the DMN alone group. This was accompanied by an 80% increase in the number of NMJs at 2 weeks, and 26% increase in mean muscle fiber diameter at 8 weeks. Conclusions: These results suggest that a nerve-derived hydrogel may improve the neuromuscular outcome following DNM.


Asunto(s)
Transferencia de Nervios , Ratas , Animales , Porcinos , Transferencia de Nervios/métodos , Hidrogeles/farmacología , Regeneración Nerviosa , Fibras Musculares Esqueléticas , Unión Neuromuscular , Músculo Esquelético/patología
4.
Heliyon ; 9(11): e22145, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38053902

RESUMEN

The penile epithelial microbiome remains underexplored. We sequenced human RNA and a segment of the bacterial 16S rRNA gene from the foreskin tissue of 144 adolescents from South Africa and Uganda collected during penile circumcision after receipt of 1-2 doses of placebo, emtricitabine + tenofovir disoproxil fumarate, or emtricitabine + tenofovir alafenamide to investigate the microbiome of foreskin tissue and its potential changes with antiretroviral use. We identified a large number of anaerobic species, including Corynebacterium acnes, which was detected more frequently in participants from South Africa than Uganda. Bacterial populations did not differ by treatment received, and no differentially abundant taxa were identified between placebo versus active drug recipients. The relative abundance of specific bacterial taxa was negatively correlated with expression of genes downstream of the innate immune response to bacteria and regulation of inflammation. Our results show no difference in the tissue microbiome of the foreskin with short-course antiretroviral use but that bacterial taxa were largely inversely correlated with inflammatory gene expression, consistent with commensal colonization.

5.
Sci Adv ; 9(49): eade1370, 2023 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-38064556

RESUMEN

Bacille Calmette-Guerin (BCG) vaccine can elicit good TH1 responses in neonates. We hypothesized that the pioneer gut microbiota affects vaccine T cell responses. Infants who are HIV exposed but uninfected (iHEU) display an altered immunity to vaccination. BCG-specific immune responses were analyzed at 7 weeks of age in iHEU, and responses were categorized as high or low. Bifidobacterium longum subsp. infantis was enriched in the stools of high responders, while Bacteroides thetaiotaomicron was enriched in low responders at time of BCG vaccination. Neonatal germ-free or SPF mice orally gavaged with live B. infantis exhibited significantly higher BCG-specific T cells compared with pups gavaged with B. thetaiotaomicron. B. infantis and B. thetaiotaomicron differentially affected stool metabolome and colonic transcriptome. Human colonic epithelial cells stimulated with B. infantis induced a unique gene expression profile versus B. thetaiotaomicron. We thus identified a causal role of B. infantis in early-life antigen-specific immunity.


Asunto(s)
Bifidobacterium longum subspecies infantis , Microbioma Gastrointestinal , Humanos , Lactante , Ratones , Animales , Vacuna BCG , Linfocitos T , Heces/microbiología
6.
J Tissue Eng ; 14: 20417314231197282, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38029018

RESUMEN

Female cancer patients who have undergone chemotherapy have an elevated risk of developing ovarian dysfunction and failure. Experimental approaches to treat iatrogenic infertility are evolving rapidly; however, challenges and risks remain that hinder clinical translation. Biomaterials have improved in vitro follicle maturation and in vivo transplantation in mice, but there has only been marginal success for early-stage human follicles. Here, we developed methods to obtain an ovarian-specific extracellular matrix hydrogel to facilitate follicle delivery and establish an in situ ovary (ISO), which offers a permissive environment to enhance follicle survival. We demonstrate sustainable follicle engraftment, natural pregnancy, and the birth of healthy pups after intraovarian microinjection of isolated exogenous follicles into chemotherapy-treated (CTx) mice. Our results confirm that hydrogel-based follicle microinjection could offer a minimally invasive delivery platform to enhance follicle integration for patients post-chemotherapy.

7.
Clin Immunol ; 255: 109750, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37660744

RESUMEN

Although effective contraceptives are crucial for preventing unintended pregnancies, evidence suggests that their use may perturb the female genital tract (FGT). A comparative analysis of the effects of the most common contraceptives on the FGT have not been evaluated in a randomized clinical trial setting. Here, we evaluated the effect of three long-acting contraceptive methods: depot medroxyprogesterone acetate(DMPA-IM), levonorgestrel(LNG) implant, and a copper intrauterine device (Cu-IUD), on the endocervical host transcriptome in 188 women from the Evidence for Contraceptive Options and HIV Outcomes Trial (ECHO) trial. Cu-IUD usage showed the most extensive transcriptomic changes, and was associated with inflammatory and anti-viral host responses. DMPA-IM usage was enriched for pathways associated with T cell responses. LNG implant had the mildest effect on endocervical gene expression, and was associated with growth factor signaling. These data provide a mechanistic basis for the diverse influence that varying contraceptives have on the FGT.


Asunto(s)
Cobre , Dispositivos Intrauterinos de Cobre , Embarazo , Femenino , Humanos , Levonorgestrel/farmacología , Anticonceptivos , Análisis de Sistemas
9.
Nurse Educ Pract ; 71: 103696, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37453370

RESUMEN

AIM: To design a modular, flipped-classroom curriculum using character animations to improve knowledge and attitudes regarding dementia care among pre-clinical nursing students. BACKGROUND: Demographic trends suggest an urgent, unmet need for nurses with interest and adequate training in caring for people with dementia and other disorders of cognition. While flipped classrooms using video show promise, little is known about specific animation techniques to impact knowledge and attitudes in preclinical nursing education. DESIGN: A curriculum was developed, implemented and assessed across three nursing schools in series, totaling 223 eligible students in the states of Connecticut and Hawaii, USA from 2019 to 2022. The evaluation included prospective pre-post assessment of knowledge, attitudes and module acceptability, as well as qualitative interpretations of needs assessment data. METHODS: The six-step curriculum development process was based on that described by Kern et al., including: 1) general needs assessment in the form of literature review; 2) targeted needs assessment, in the form of faculty stakeholder meetings, a student focus group and baseline surveys; 3) optimization of learning objectives based on needs; 4) development of a pedagogical approach, namely animated, interactive modules informed by previously described best practices in animation development; 5) implementation across three different nursing schools; and 6) assessment of the learners and evaluation of the curriculum, primarily via surveys and engagement metadata. RESULTS: Needs assessments confirmed the importance of prior experiences, sense of mission and other affective elements as key factors mitigating learners' baseline receptiveness to training and careers in cognition-related care. Students at all three institutions rated the modules' impact on their dementia-related attitudes highly, however these ratings were statistically significantly lower when both modules were delivered as a single assignment at one site. Knowledge quiz scores significantly increased from baseline at all three sites. Only 2.6% of respondents would have preferred a text-based reading assignment. Acceptability scores, including clarity, relevance, entertainment, attention and complexity, were generally rated highly, but attention and entertainment were rated significantly lower when both modules were administered as a single assignment. CONCLUSION: Cognition and Dementia with Raymond and Brain demonstrates the successful blending of animation industry workflows with best practices of curriculum development to create a novel, animated module series that is acceptable and effective in priming nursing students with the attitudes and knowledge to continue learning about cognition and its disorders.


Asunto(s)
Demencia , Estudiantes de Enfermería , Humanos , Estudiantes de Enfermería/psicología , Estudios Prospectivos , Curriculum , Cognición , Encéfalo , Actitud
10.
J Migr Health ; 7: 100183, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37063649

RESUMEN

Background: There is a paucity of literature regarding dermatologic conditions in migrant and refugee populations. Methods: We conducted a cross-sectional study of all adult refugees resettling in a region of Connecticut, U.S. from 7 January 2015 to 20 November 2018. We conducted a manual chart review to determine dermatologic conditions diagnosed during and within one year of resettlement. We used multivariable logistic regression to determine demographic and clinical factors associated with having any dermatologic condition. Results: We included 545 refugees primarily from Afghanistan (40.6%), Syria (24.6%) and Iraq (10.5%), with a median (interquartile range) age of 33 (28-40) years. Of the 545 participants, 213 (39.1%) had dermatologic conditions. Fifty-four participants (25%) had more than one dermatologic condition and 114 (53.5%) were diagnosed within the first month of resettlement. The most common categories of conditions were cutaneous infections (24.9%), inflammatory conditions (11.1%), and scar or burn (10.7%). Tobacco use was associated with having a cutaneous infection (OR 2.37, 95%CI:1.09-4.95), and younger age was associated with having a scar or burn (for each year increase in age, OR 0.95, 95%CI:0.91-0.99). Conclusion: Dermatologic conditions are common among adult refugees. The majority of conditions were diagnosed in the first month following resettlement suggesting that a high number of dermatologic conditions arise or go undetected and untreated during the migration process.

11.
Plast Reconstr Surg ; 152(3): 458e-467e, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-36946873

RESUMEN

BACKGROUND: Nerve transection is the most common form of peripheral nerve injury. Treatment of peripheral nerve injury has primarily focused on stabilization and mechanical cues to guide extension of the regenerating growth cone across the site of transection. The authors investigated the effects of a peripheral nerve matrix (PNM) hydrogel on recovery after nerve transection. METHODS: The authors used rodent models to determine the effect of PNM on axon extension, electrophysiologic nerve conduction, force generation, and neuromuscular junction formation after nerve transection and repair. The authors complemented this work with in vivo and in vitro fluorescence-activated cell sorting and immunohistochemistry approaches to determine the effects of PNM on critical cell populations early after repair. RESULTS: Extension of axons from the proximal stump and overall green fluorescent protein-positive axon volume within the regenerative bridge were increased in the presence of PNM compared with an empty conduit ( P < 0.005) 21 days after repair. PNM increased electrophysiologic conduction (compound muscle action potential amplitude) across the repair site ( P < 0.05) and neuromuscular junction formation ( P = 0.04) 56 days after repair. PNM produced a shift in macrophage phenotype in vitro and in vivo ( P < 0.05) and promoted regeneration in a murine model used to characterize the early immune response to PNM ( P < 0.05). CONCLUSION: PNM, delivered by subepineural injection, promoted recovery after nerve transection with immediate repair, supporting a beneficial macrophage response, axon extension, and downstream remodeling using a range of clinically relevant outcome measures. CLINICAL RELEVANCE STATEMENT: This article describes an approach for subepineural injection at the site of nerve coaptation to modulate the response to injury and improve outcomes.


Asunto(s)
Traumatismos de los Nervios Periféricos , Ratones , Animales , Traumatismos de los Nervios Periféricos/cirugía , Hidrogeles , Nervios Periféricos/fisiología , Axones , Conducción Nerviosa , Regeneración Nerviosa/fisiología
12.
Viruses ; 15(3)2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36992467

RESUMEN

The interaction between cervicovaginal virome, bacteriome and genital inflammation has not been extensively investigated. We assessed the vaginal DNA virome from 33 South African adolescents (15-19 years old) using shotgun DNA sequencing of purified virions. We present analyses of eukaryote-infecting DNA viruses, with a focus on human papillomavirus (HPV) genomes and relate these to the vaginal bacterial microbiota (assessed by 16S rRNA gene sequencing) and cytokines (assessed by Luminex). The DNA virome included single-stranded (Anelloviridae, Genomoviridae) and double-stranded DNA viruses (Adenoviridae, Alloherpesviridae, Herpesviridae, Marseilleviridae, Mimiviridae, Polyomaviridae, Poxviridae). We identified 110 unique, complete HPV genomes within two genera (Alphapapillomavirus and Gammapapillomavirus) representing 40 HPV types and 12 species. Of the 40 HPV types identified, 35 showed positive co-infection patterns with at least one other type, mainly HPV-16. HPV-35, a high-risk genotype currently not targeted by available vaccines, was the most prevalent HPV type identified in this cohort. Bacterial taxa commonly associated with bacterial vaginosis also correlated with the presence of HPV. Bacterial vaginosis, rather than HPV, was associated with increased genital inflammation. This study lays the foundation for future work characterizing the vaginal virome and its role in women's health.


Asunto(s)
Herpesviridae , Microbiota , Infecciones por Papillomavirus , Vaginosis Bacteriana , Femenino , Adolescente , Humanos , Adulto Joven , Adulto , Vaginosis Bacteriana/microbiología , Virus del Papiloma Humano , Citocinas , ARN Ribosómico 16S/genética , Sudáfrica , Vagina , Microbiota/genética , Papillomaviridae/genética , Bacterias/genética , Herpesviridae/genética , Inflamación/complicaciones
14.
Nat Commun ; 14(1): 499, 2023 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-36717556

RESUMEN

Effective contraceptives are a global health imperative for reproductive-aged women. However, there remains a lack of rigorous data regarding the effects of contraceptive options on vaginal bacteria and inflammation. Among 218 women enrolled into a substudy of the ECHO Trial (NCT02550067), we evaluate the effect of injectable intramuscular depot medroxyprogesterone acetate (DMPA-IM), levonorgestrel implant (LNG), and a copper intrauterine device (Cu-IUD) on the vaginal environment after one and six consecutive months of use, using 16S rRNA gene sequencing and multiplex cytokine assays. Primary endpoints include incident BV occurrence, bacterial diversity, and bacterial and cytokine concentrations. Secondary endpoints are bacterial and cytokine concentrations associated with later HIV seroconversion. Participants randomized to Cu-IUD exhibit elevated bacterial diversity, increased cytokine concentrations, and decreased relative abundance of lactobacilli after one and six months of use, relative to enrollment and other contraceptive options. Total bacterial loads of women using Cu-IUD increase 5.5 fold after six months, predominantly driven by increases in the concentrations of several inflammatory anaerobes. Furthermore, growth of L. crispatus (MV-1A-US) is inhibited by Cu2+ ions below biologically relevant concentrations, in vitro. Our work illustrates deleterious effects on the vaginal environment induced by Cu-IUD initiation, which may adversely impact sexual and reproductive health.


Asunto(s)
Dispositivos Intrauterinos de Cobre , Femenino , Humanos , Adulto , Acetato de Medroxiprogesterona/farmacología , Lactobacillus , ARN Ribosómico 16S/genética , Bacterias Anaerobias , Anticonceptivos
15.
Microbiol Resour Announc ; 12(1): e0114322, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36533922

RESUMEN

Other than for papillomaviruses, there is a paucity of whole-genome sequences for bacteriophages and eukaryote-infecting viruses isolated from the female genital tract. Here, we report the genome sequences of 16 microviruses, 3 anelloviruses, 2 polyomaviruses, 1 genomovirus, and 1 caudovirus that were identified in vaginal secretion samples from adolescents in South Africa.

16.
Patient Educ Couns ; 106: 180-187, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36371243

RESUMEN

OBJECTIVES: Effective education and support for adults with dementia and their caregivers around pandemic issues is critical for protecting them. Animation-based learning has shown promise in patient education. We collaborated with educators and support staff at Alzheimer's Association Connecticut (AACT) to conduct a mixed-methods study and develop an animated e-curriculum addressing pandemic related challenges. METHODS: We conducted focus groups and surveys with dementia and caregiver educators and support staff at AACT for the initial needs assessment and the later e-curriculum evaluation. An interdisciplinary team of educators followed a step-wise process to transform the needs assessment results into an animation based e-curriculum. RESULTS: Participants identified the following pandemic challenges: 1) social isolation, 2) caregiver fatigue, 3) safety, and 4) difficulty navigating the healthcare system. The overall quality and usefulness of the e-curriculum was "very good" or "excellent". CONCLUSIONS: An animated e-curriculum addressing pandemic related issues relevant to adults with dementia and caregivers had positive reviews and was associated with improvement in self-reported ability to perform curriculum objectives among community dementia educators. PRACTICE IMPLICATIONS: The pandemic challenges identified may facilitate the development of further resources. Additionally, this project may serve as a guide for clinicians interested in incorporating animation into education efforts.


Asunto(s)
COVID-19 , Demencia , Adulto , Humanos , Cuidadores/educación , Demencia/terapia , COVID-19/epidemiología , Curriculum , Evaluación de Necesidades
17.
Microbiol Spectr ; 10(6): e0249122, 2022 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-36314979

RESUMEN

Whether antibiotic treatment during gestation impacts T cell immunity to vaccination in offspring is unexplored. Dams treated with polymyxin B (PMB) during gestation (Mg) displayed altered microbial communities prior to delivery compared to control dams (Mc). Differences in microbiota were also evident in pups born to polymyxin B-treated dams (Pg) compared to control pups (Pc). When pups were immunized with Bacille Calmette-Guerin (BCG), we observed no difference in TB10.4-specific T cells between Pc and Pg 4 weeks postimmunization. Significantly fewer splenic CD4 T cells from BCG-vaccinated Pg produced interleukin-2 (IL-2) upon stimulation, suggesting a possible functional deficiency. There was no difference in purified protein derivative (PPD)-specific IgG between Pc and Pg at this time point. However, when infected with Mycobacterium tuberculosis, Pg displayed significantly higher bacterial burden in the lung than Pc. Our results show that maternal PMB treatment during gestation may not impact splenic antigen-specific T cell responses following BCG vaccination but alters susceptibility to M. tuberculosis in offspring. IMPORTANCE The composition of the pioneer microbiota that colonize the infant gut are determined by the mother. Polymyxin B-induced changes in the maternal microbiota during pregnancy impact the offspring gut microbiota but not vaccine-specific CD4 T cell response. However, when infected with Mycobacterium tuberculosis, offspring born to mothers with an altered gut microbiota are susceptible to infection compared to those born to mothers not exposed to antibiotics.


Asunto(s)
Mycobacterium bovis , Mycobacterium tuberculosis , Femenino , Embarazo , Antibacterianos/farmacología , Antibacterianos/metabolismo , Vacuna BCG , Linfocitos T CD4-Positivos , Polimixina B/farmacología , Vacunación , Animales
18.
Front Microbiol ; 13: 935444, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36090093

RESUMEN

Mycobacterium tuberculosis (M.tb) has led to approximately 1.3 million deaths globally in 2020 according to the World Health Organization (WHO). More effective treatments are therefore required to prevent the transmission of M.tb. Although Bacille Calmette-Guérin (BCG), a prophylactic vaccine against M.tb, already exists, other vaccines are being developed that could help boost BCG's noted incomplete protection. This includes ID93 + GLA-SE, an adjuvanted protein vaccine which is being tested in Phase 2 clinical trials. The aim of this study was to test new lipid-based adjuvant formulations with ID93 in the context of a therapeutic vaccine, which we hypothesize would act as an adjunct to drug treatment and provide better outcomes, such as survival, than drug treatment alone. The recent success of another adjuvanted recombinant protein vaccine, M72 + AS01E (GlaxoSmithKline Biologicals), which after 3 years provided approximately 50% efficacy against TB pulmonary disease, is paving the way for new and potentially more effective vaccines. We show that based on selected criteria, including survival, T helper 1 cytokine responses, and resident memory T cells in the lung, that a liposomal formulation of GLA with QS-21 (GLA-LSQ) combined with ID93 provided enhanced protection over drug treatment alone.

19.
J Biomed Mater Res A ; 110(11): 1738-1748, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36082974

RESUMEN

Neuroma formation following limb amputation is a prevalent and debilitating condition that can deeply affect quality of life and productivity. Several approaches exist to prevent or treat neuromas; however, no approach is either consistently reliable or surgically facile, with high rates of neuroma occurrence and/or recurrence. The present study describes the development and testing of a xenogeneic nerve cap graft made from decellularized porcine nerve. The grafts were tested in vitro for cellular removal, cytotoxicity, mechanical properties, and morphological characteristics. The grafts were then tested in rat sciatic nerve gap reconstruction and nerve amputation models for 8 weeks. Gross morphology, electrophysiology, and histopathology assessments were performed to determine the ability of the grafts to limit pathologic nerve regrowth. In vitro testing showed well decellularized and demyelinated nerve cap graft structures without any cytotoxicity from residual reagents. The grafts had a proximal socket for the proximal nerve stump and longitudinally oriented internal pores. Mechanical and surgical handling properties suggested suitability for implantation as a nerve graft. Following 8 weeks in vivo, the grafts were well integrated with the proximal and distal nerve segments without evidence of fibrotic adhesions to the surrounding tissues or bulbous outgrowth of the nerve. Electrophysiology revealed absence of nerve conduction within the remodeled nerve cap grafts and significant downstream muscle atrophy. Histologic evaluation showed well organized but limited axonal regrowth within the grafts without fibrous overgrowth or neuromatous hypercellularity. These results provide proof of concept for a novel xenograft-based approach to neuroma prevention.


Asunto(s)
Neuroma , Calidad de Vida , Animales , Axones , Xenoinjertos , Humanos , Regeneración Nerviosa , Neuroma/patología , Neuroma/prevención & control , Ratas , Nervio Ciático/cirugía , Porcinos
20.
PLoS One ; 17(8): e0273336, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36006938

RESUMEN

Temporomandibular joint (TMJ) Meniscus removal is an option for the patient to regain full range of motion if the disc is irreversibly damaged or unable to be reduced. However, this procedure leaves the joint vulnerable to condylar remodeling and degeneration. We have shown that extracellular matrix (ECM) scaffolds remodel into a tissue with near native TMJ meniscus in previous studies. The next step towards clinical translation is to manufacture the ECM scaffold as a device under good manufacturing practices (GMP) and test it in a pre-clinical animal study under good laboratory practices (GLP). The primary objective of this study was to evaluate the in-vivo histopathological response to a Prototype GMP manufactured device made of decellularized porcine small intestinal submucosa (SIS), by observing for signs of surrounding tissue reaction to the device that are indicative of an adverse host response in comparison to an empty control at 21 days post-surgical implantation in a canine TMJ meniscus removal and implant model in a GLP setting. The conclusive findings were that the ECM device is safe for placement in the TMJ. After 21 days post implantation, histology of tissue surrounding the device and draining lymph nodes showed that the Prototype GMP device had no negative effects compared to the empty site (as evaluated by the board-certified veterinary pathologist). Furthermore, there was a lack of negative findings for clinical pathology (hematology and clinical chemistry), mortality, and body weight/weight change. Future studies will go to one year after implantation to show that the remodel device remains as a viable tissue with near native mechanical properties.


Asunto(s)
Menisco , Disco de la Articulación Temporomandibular , Animales , Perros , Matriz Extracelular/química , Intestino Delgado , Prótesis e Implantes , Porcinos , Articulación Temporomandibular , Disco de la Articulación Temporomandibular/fisiología , Disco de la Articulación Temporomandibular/cirugía , Ingeniería de Tejidos/métodos , Andamios del Tejido/efectos adversos
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