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1.
ChemMedChem ; : e202400310, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090029

RESUMO

Studies of the structure and dynamics of oligomeric aggregates of amyloidogenic peptides pose challenges due to their transient nature. This concept article provides a brief overview of various nucleation mechanisms with reference to the classical nucleation theory and illustrates the advantages of incubating amyloidogenic peptides in reverse micelles (RMs). The use of RMs not only facilitates size regulation of oligomeric aggregates but also provides an avenue to explore protein-protein interactions among the oligomeric aggregates of various amyloidogenic peptides. Additionally, we envision the feasibility of preparing brain tissue-derived oligomeric aggregates using RMs, potentially advancing the development of monoclonal antibodies with enhanced potency against these pathological species in vivo.

2.
J Mech Behav Biomed Mater ; 157: 106658, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39018919

RESUMO

Although the sacroiliac (SI) joint can be a source of lower back and buttock pain, no comprehensive characterization studies on SI cartilage have been conducted. Using the minipig as a large animal model, this study conducted the first biomechanical, biochemical, and histological characterization of SI joint cartilage. Because previous literature has reported that sacral cartilage and iliac cartilage within the SI joint are histologically distinct, concomitantly it was expected that functional properties of the sacral cartilage would differ from those of the iliac cartilage. Creep indentation, uniaxial tension, biochemical, and histological analyses were conducted on the sacral and iliac cartilage of skeletally mature female Yucatan minipigs (n = 6-8 for all quantitative tests). Concurring with prior literature, the iliac cartilage appeared to be more fibrous than the sacral cartilage. Glycosaminoglycan content was 2.2 times higher in the sacral cartilage. The aggregate modulus of the sacral cartilage was 133 ± 62 kPa, significantly higher than iliac cartilage, which only had an aggregate modulus of 51 ± 61 kPa. Tensile testing was conducted in both cranial-caudal and ventral-dorsal axes, and Young's modulus values ranged from 2.5 ± 1.5 MPa to 13.6 ± 1.5 MPa, depending on anatomical structure (i.e., sacral vs. iliac) and orientation of the tensile test. The Young's modulus of sacral cartilage was 5.5 times higher in the cranial-caudal axis and 2.0 times higher in the ventral-dorsal axis than the iliac cartilage. The results indicate that the sacral and iliac cartilages are functionally distinct from each other. Understanding the distinct differences between sacral and iliac cartilage provides insight into the structure and function of the SI joint, which may inform future research aimed at repairing SI joint cartilage.


Assuntos
Fenômenos Mecânicos , Articulação Sacroilíaca , Porco Miniatura , Animais , Suínos , Fenômenos Biomecânicos , Feminino , Cartilagem/fisiologia , Cartilagem/citologia , Teste de Materiais , Cartilagem Articular/fisiologia , Cartilagem Articular/citologia , Testes Mecânicos , Glicosaminoglicanos/metabolismo
4.
Biofabrication ; 16(3)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38768586

RESUMO

Toward the translation of allogeneic cell therapy products, cell banks are needed not only to manufacture the final human product but also during the preclinical evaluation of an animal-based analogous cellular product (ACP). These cell banks need to be established at both the master cell bank (MCB) level and the working cell bank (WCB) level. Inasmuch as most of the development of cell therapy products is at academic centers, it is imperative that academic researchers understand how to establish MCBs and WCBs within an academic environment. To illustrate this process, using articular cartilage as the model, a cell bank for an ACP was developed (MCBs at passage 2, WCBs at passage 5) to produce self-assembled neocartilage for preclinical evaluation (constructs at passage 7). The cell bank system is estimated to be able to produce between 160 000 and 400 000 constructs for each of the six MCBs. Overall, the ACP cell bank yielded constructs that are analogous to the intended human product, which is critical toward conducting preclinical evaluations of the ACP for inclusion in an Investigational New Drug application to the FDA.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos , Humanos , Animais , Cartilagem Articular/citologia , Engenharia Tecidual , Bancos de Tecidos
5.
Front Oncol ; 14: 1378973, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38694788

RESUMO

Introduction: Alongside the improved survival of nasopharyngeal cancer (NPC), late radiation toxicities are alarmingly hampering survivors' quality of life. A patient-reported symptom burden survey is lacking to address the unmet need for symptom management among local NPC survivors. Methods: A single-center cross-sectional survey was conducted on 211 NPC survivors who had completed radiation therapy for three to 120 months. We employed the Chinese version M. D. Anderson Symptom Inventory - Head & Neck Module (MDASI-HN-C), Functional Assessment of Cancer Therapy - Head & Neck (FACT-HN-C), and a question extracted from the Cancer Survivors' Unmet Needs Measure (CaSUN). Results: Two hundred valid responses were collected. Participants suffered from at least four moderate to severe symptoms (mean = 4.84, SD = 4.99). The top five severe symptoms were dry mouth, mucus problems, difficulty swallowing or chewing, teeth or gum problems, and memory problems. MDASI-HN-C subscales were negatively correlated with the physical, emotional, functional, and HN-specific domains of the FACT-HN-C. The unmet need for symptom management was positively associated with symptom burden, either general symptoms (Adjusted odds ratio [ORadj] = 1.566, 95% CI = 1.282 - 1.914, p < 0.001) or top-5 symptoms (ORadj = 1.379, 95% CI = 1.185 - 1.604, p < 0.001), while negatively associated with post-RT time (ORadj = 0.981, 95% CI [0.972, 0.991], p < 0.001). Conclusion: Virtually all NPC survivors suffer from late toxicities, which interplay with survivors' perceptions intricately to affect their unmet needs for symptom management. Personalized supportive care strategies with regular assessments and stratifications are warranted.

6.
Nat Rev Rheumatol ; 20(6): 323-346, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38740860

RESUMO

Articular cartilage was expected to be one of the first successfully engineered tissues, but today, cartilage repair products are few and they exhibit considerable limitations. For example, of the cell-based products that are available globally, only one is marketed for non-knee indications, none are indicated for severe osteoarthritis or rheumatoid arthritis, and only one is approved for marketing in the USA. However, advances in cartilage tissue engineering might now finally lead to the development of new cartilage repair products. To understand the potential in this field, it helps to consider the current landscape of tissue-engineered products for articular cartilage repair and particularly cell-based therapies. Advances relating to cell sources, bioactive stimuli and scaffold or scaffold-free approaches should now contribute to progress in therapeutic development. Engineering for an inflammatory environment is required because of the need for implants to withstand immune challenge within joints affected by osteoarthritis or rheumatoid arthritis. Bringing additional cartilage repair products to the market will require an understanding of the translational vector for their commercialization. Advances thus far can facilitate the future translation of engineered cartilage products to benefit the millions of patients who suffer from cartilage injuries and arthritides.


Assuntos
Cartilagem Articular , Engenharia Tecidual , Engenharia Tecidual/métodos , Humanos , Alicerces Teciduais , Osteoartrite/terapia , Pesquisa Translacional Biomédica/métodos , Artrite Reumatoide/terapia , Animais
7.
Mol Psychiatry ; 29(7): 2084-2094, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38383769

RESUMO

CD33 is a transmembrane receptor expressed on cells of myeloid lineage and regulates innate immunity. CD33 is a risk factor for Alzheimer's disease (AD) and targeting CD33 has been a promising strategy drug development. However, the mechanism of CD33's action is poorly understood. Here we investigate the mechanism of anti-CD33 antibody HuM195 (Lintuzumab) and its single-chain variable fragment (scFv) and examine their therapeutic potential. Treatment with HuM195 full-length antibody or its scFv increased phagocytosis of ß-amyloid 42 (Aß42) in human microglia and monocytes. This activation of phagocytosis was driven by internalization and degradation of CD33, thereby downregulating its inhibitory signal. HumM195 transiently induced CD33 phosphorylation and its signaling via receptor dimerization. However, this signaling decayed with degradation of CD33. scFv binding to CD33 leads to a degradation of CD33 without detection of the CD33 dimerization and signaling. Moreover, we found that treatments with either HuM195 or scFv promotes the secretion of IL33, a cytokine implicated in microglia reprogramming. Importantly, recombinant IL33 potentiates the uptake of Aß42 in monocytes. Collectively, our findings provide unanticipated mechanistic insight into the role of CD33 signaling in both monocytes and microglia and define a molecular basis for the development of CD33-based therapy of AD.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Microglia , Monócitos , Fagocitose , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico , Transdução de Sinais , Anticorpos de Cadeia Única , Microglia/metabolismo , Microglia/efeitos dos fármacos , Humanos , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Peptídeos beta-Amiloides/metabolismo , Fagocitose/efeitos dos fármacos , Fagocitose/fisiologia , Anticorpos de Cadeia Única/farmacologia , Anticorpos de Cadeia Única/metabolismo , Transdução de Sinais/efeitos dos fármacos , Doença de Alzheimer/metabolismo , Monócitos/metabolismo , Monócitos/efeitos dos fármacos , Anticorpos Monoclonais Humanizados/farmacologia , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Fosforilação/efeitos dos fármacos
8.
Am J Sports Med ; 52(4): 1068-1074, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38353029

RESUMO

BACKGROUND: Chlorhexidine gluconate (CHG) solution is commonly used as an antiseptic irrigation for bacterial decontamination during orthopaedic surgery. Although the chondrotoxicity of CHG on articular cartilage has been reported, the full extent of CHG-related chondrotoxicity and its effects on the extracellular matrix and mechanical properties are unknown. PURPOSE: To investigate the in vitro effects of a single 1-minute CHG exposure on the viability, biochemical content, and mechanics of native articular cartilage explants. STUDY DESIGN: Controlled laboratory study. METHODS: Articular cartilage explants (6 per group) were harvested from femoral condyles of the porcine stifle and sectioned at tidemark. Explants were bathed in CHG solution (0.05% CHG in sterile water) at varying concentrations (0% control, 0.01% CHG, and 0.05% CHG) for 1 minute, followed by complete phosphate-buffered saline wash and culture in chondrogenic medium. At 7 days after CHG exposure, cell viability, matrix content (collagen and glycosaminoglycan [GAG]), and compressive mechanical properties (creep indentation testing) were assessed. RESULTS: One-minute CHG exposure was chondrotoxic to explants, with both 0.05% CHG (2.6% ± 4.1%) and 0.01% CHG (76.3% ± 8.6%) causing a decrease in chondrocyte viability compared with controls (97.5% ± 0.6%; P < .001 for both). CHG exposure at either concentration had no significant effect on collagen content, while 0.05% CHG exposure led to a significant decrease in mean GAG per wet weight compared with the control group (2.6% ± 1.7% vs 5.2% ± 1.9%; P = .029). There was a corresponding weakening of mechanical properties in explants treated with 0.05% CHG compared with controls, with decreases in mean aggregate modulus (177.8 ± 90.1 kPa vs 280.8 ± 19.8 kPa; P < .029) and shear modulus (102.6 ± 56.5 kPa vs 167.9 ± 16.2 kPa; P < .020). CONCLUSION: One-minute exposure to CHG for articular cartilage explants led to dose-dependent decreases in chondrocyte viability, GAG content, and compressive mechanical properties. This raises concern for the risk of mechanical failure of the cartilage tissue after CHG exposure. CLINICAL RELEVANCE: Clinicians should be judicious regarding the use of CHG irrigation at these concentrations in the presence of native articular cartilage.


Assuntos
Cartilagem Articular , Animais , Suínos , Clorexidina/toxicidade , Clorexidina/análise , Condrócitos , Glicosaminoglicanos , Colágeno/análise
9.
Interv Neuroradiol ; : 15910199231226293, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38233047

RESUMO

OBJECTIVE: Carotid artery webs are an underappreciated cause of recurrent ischemic stroke, and may represent a significant portion of cryptogenic stroke. Evidence-based guidelines for the management of symptomatic carotid webs do not exist. The goal of this study is to audit our local experience for patients with symptomatic carotid artery webs undergoing carotid stenting as a treatment option, along with describing the hypothesized dynamic physiology of carotid webs. METHODS: All patients undergoing stenting for symptomatic carotid artery web at two comprehensive regional stroke centers with high endovascular thrombectomy volume from January 1, 2012 to March 1, 2021 were included. The modified Rankin Scale (mRS) score was used to define functional outcome at 3 months after stenting. RESULTS: Fourteen consecutive patients with symptomatic carotid artery webs underwent stenting. Twelve patients were female (86%), with a median age of 54 (IQR, 48-64) years across all patients. Stroke was the qualifying event in 12 (86%) patients and TIA in 2. Eleven patients (11/14, 79%) achieved a mRS score of 0-2 at 90 days, 2 (14%) were mRS 3-5, and one patient was lost to follow-up. The median follow-up was 12 months (IQR, 10-12). There was no recurrent stroke or TIA like symptoms in any patients. CONCLUSIONS: Carotid stenting appears to be safe at preventing recurrent stroke/TIA with a median follow-up of 12 months in this retrospective multicenter observational study.

10.
Eye (Lond) ; 38(2): 386-392, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37598261

RESUMO

BACKGROUND: Autoimmunity and deficiency of the transcription factor autoimmune regulator protein (AIRE) are known associations with Down syndrome (DS). Lack of AIRE abrogates thymic tolerance. The autoimmune eye disease associated with DS has not been characterized. We identified a series of subjects with DS (n = 8) and uveitis. In three consecutive subjects, we tested the hypothesis that autoimmunity to retinal antigens might be a contributing factor. SUBJECTS/METHODS: This was a multicentred, retrospective case series. Deidentified clinical data of subjects with both DS and uveitis were collected via questionnaire by uveitis-trained ophthalmologists. Anti-retinal autoantibodies (AAbs) were detected using an Autoimmune Retinopathy Panel tested in the OHSU Ocular Immunology Laboratory. RESULTS: We characterized eight subjects (mean age 29 [range, 19-37] years). The mean age of detected uveitis onset was 23.5 [range, 11-33] years. All eight subjects had bilateral uveitis (p < 0.001 based on comparison to published university referral patterns), with anterior and intermediate uveitis found in six and five subjects respectively. Each of three subjects tested for anti-retinal AAbs was positive. Detected AAbs included anti-carbonic anhydrase II, anti-enolase, anti-arrestin, and anti-aldolase. DISCUSSION: A partial deficiency in the AIRE on chromosome 21 has been described in DS. The similarities in the uveitis presentations within this patient group, the known autoimmune disease predisposition in DS, the recognized association of DS and AIRE deficiency, the reported detection of anti-retinal antibodies in patients with DS in general, and the presence of anti-retinal AAbs in three subjects in our series supports a causal association between DS and autoimmune eye disease.


Assuntos
Doenças Autoimunes , Síndrome de Down , Doenças Retinianas , Uveíte , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Doenças Autoimunes/complicações , Síndrome de Down/complicações , Estudos Retrospectivos , Autoanticorpos , Uveíte/complicações
11.
Vasc Endovascular Surg ; 58(3): 294-301, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37878392

RESUMO

BACKGROUND: This study's objective is to evaluate the emotional experiences, coping mechanisms, and support resources for Canadian vascular surgeons and trainees following an adverse patient event or near miss. METHODS: This is a cross-sectional survey study of all Canadian Society for Vascular Surgery (CSVS) members from October to November 2021. We collected data on participant experiences with adverse events, their emotional responses, the coping mechanisms used, and their perceptions on available support resources. RESULTS: The survey was sent to 233 CSVS members yielding 66 responses. The majority (77%) of respondents had experiences with adverse event causing serious patient harm. The most common negative experience following an adverse event included feelings of negativity towards oneself, general distress, and anxiety about potential for future errors. The most common coping mechanism was seeking advice from a mentor or close colleague. Peers (82%) and senior colleagues (59%) were the most preferred sources of support. Most of the respondents would reach out to a mentor if they had 1, but 30% reported no mentor or close colleague for support. CONCLUSION: Adverse patient events and near misses have serious negative impact on the lives of Canadian vascular surgeons and trainees. Peers and senior colleagues are the most desired source for support, but this is not universally available. Organized efforts are needed to bring awareness in our vascular surgery community on the ubiquitous nature and detrimental effects of adverse events.


Assuntos
Emoções , Cirurgiões , Humanos , Estudos Transversais , Canadá , Resultado do Tratamento , Cirurgiões/psicologia , Inquéritos e Questionários , Capacidades de Enfrentamento
12.
Artigo em Inglês | MEDLINE | ID: mdl-38110247

RESUMO

Homologous protein sequences are wonderfully diverse, indicating many possible evolutionary "solutions" to the encoding of function. Consequently, one can construct statistical models of protein sequence by analyzing amino acid frequency across a large multiple sequence alignment. A central premise is that covariance between amino acid positions reflects coevolution due to a shared functional or biophysical constraint. In this review, we describe the implementation and discuss the advantages, limitations, and recent progress on two coevolution-based modeling approaches: (1) Potts models of protein sequence (direct coupling analysis [DCA]-like), and (2) the statistical coupling analysis (SCA). Each approach detects interesting features of protein sequence and structure-the former emphasizes local physical contacts throughout the structure, while the latter identifies larger evolutionarily coupled networks of residues. Recent advances in large-scale gene synthesis and high-throughput functional selection now motivate additional work to benchmark model performance across quantitative function prediction and de novo design tasks.


Assuntos
Aminoácidos , Proteínas , Proteínas/metabolismo , Aminoácidos/genética , Modelos Estatísticos , Evolução Molecular , Evolução Biológica
13.
Cancers (Basel) ; 15(23)2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38067408

RESUMO

Despite advances in head and neck cancer treatment, virtually all patients experience chemoradiation-induced toxicities. Oral mucositis (OM) and dysphagia are among the most prevalent and have a systemic impact on patients, hampering treatment outcome and harming quality of life. Accurate prediction of severe cases is crucial for improving management strategies and, ultimately, patient outcomes. This scoping review comprehensively maps the reported predictors and critically evaluates the performance, methodology, and reporting of predictive models for these conditions. A total of 174 studies were identified from database searches, with 73 reporting OM predictors, 97 reporting dysphagia predictors, and 4 reporting both OM and dysphagia predictors. These predictors included patient demographics, tumor classification, chemoradiotherapy regimen, radiation dose to organs-at-risk, genetic factors, and results of clinical laboratory tests. Notably, many studies only conducted univariate analysis or focused exclusively on certain predictor types. Among the included studies, numerous predictive models were reported: eight for acute OM, five for acute dysphagia, and nine for late dysphagia. The area under the receiver operating characteristic curve (AUC) ranged between 0.65 and 0.81, 0.60 and 0.82, and 0.70 and 0.85 for acute oral mucositis, acute dysphagia, and late dysphagia predictive models, respectively. Several areas for improvement were identified, including the need for external validation with sufficiently large sample sizes, further standardization of predictor and outcome definitions, and more comprehensive reporting to facilitate reproducibility.

14.
JVS Vasc Sci ; 4: 100127, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928834

RESUMO

Objective: Case reports, tissue pathology, and autopsies have suggested that the hydrophilic polymer coating designed to improve endovascular deliverability and minimize vessel trauma can embolize and be associated with adverse outcomes such as ischemia, infarction, and death. This study sought to determine whether hydrophilic polymers shed off commercially available sheaths in a controlled in vitro environment, with the hypothesis that significant differences between coated and uncoated (control) sheaths would be found. Methods: Six sheaths from each manufacturer, including Zenith Alpha abdominal endovascular stent grafts (Cook Medical), DrySeal sheaths (W.L. Gore & Associates), and Sentrant Introducer sheaths (Medtronic), were tested in an in vitro environment. Noncoated Check-Flo performer introducer sheaths (Cook Medical) were used as controls. Each test circuit ran for 150 minutes at an output of 3 L/min, the circuit was then drained and the fluid collected. Quantitative analysis included weighing the dried filter paper and using particle size light scattering to quantify the particle size and count. Attenuated total reflectance spectroscopy was also used. Results: Each of the three coated sheaths had significantly greater shedding compared with the control sheaths. The Cook Zenith alpha sheath had significantly more residue weight (2.87 ± 0.52 mg/L) than the Gore DrySeal (1.07 ± 0.06 mg/L) and Medtronic Sentrant introducer (0.98 ± 0.14 mg/L) sheaths. The average particle size was not significantly different between the coated and uncoated (control) sheaths. Attenuated total reflectance spectroscopy identified sheath particulate in the Cook Zenith Alpha and Medtronic Sentrant samples. Conclusions: Polymer embolization was present and significantly greater in all three commercially available hydrophilic sheaths compared with the control group. Further investigation is needed into the clinical significance of these findings.

15.
Cartilage ; : 19476035231214724, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38018451

RESUMO

OBJECTIVE: The use of porcine animal models for cartilage injury has increased recently due to their similarity with humans with regard to cartilage thickness, limited intrinsic healing of chondral defects, and joint loading biomechanics. However, variations in the mechanical and biochemical properties of porcine hip articular cartilage among various tissue ages and weightbearing (WB) regions are still unknown. This study's aim was to characterize the mechanical and biochemical properties of porcine hip articular cartilage across various ages and WB regions. METHODS: Articular cartilage explants were harvested from WB and non-weightbearing (NWB) surfaces of the femoral head and acetabulum of domesticated pigs (Sus scrofa domesticus) at fetal (gestational age: 80 days), juvenile (6 months), and adult (2 years) ages. Explants underwent compressive stress-relaxation mechanical testing, biochemical analysis for total collagen and glycosaminoglycan (GAG) content, and histological staining. RESULTS: Juvenile animals consistently had the highest mechanical properties, with 2.2- to 7.6-time increases in relaxation modulus, 1.3- to 2.3-time increases in instantaneous modulus, and 4.1- to 14.2-time increases in viscosity compared with fetal cartilage. Mechanical properties did not significantly differ between the WB and NWB regions. Collagen content was highest in the NWB regions of the juvenile acetabulum (65.3%/dry weight [DW]) and femoral head (75.4%/DW) cartilages. GAG content was highest in the WB region of the juvenile acetabulum (23.7%/DW) and the WB region of the fetal femoral head (27.5%/DW) cartilages. Histological staining for GAG and total collagen content followed the trends from the quantitative biochemical assays. CONCLUSION: This study provides a benchmark for the development and validation of preclinical porcine models for hip cartilage pathologies.

16.
Trends Pharmacol Sci ; 44(11): 743-745, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37832526

Assuntos
Proteólise , Humanos
17.
Acta Biomater ; 169: 130-137, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37579910

RESUMO

The tunica albuginea (TA) of the penis is an elastic layer that serves a structural role in penile erection. Disorders affecting the TA cause pain, deformity, and erectile dysfunction. There is a substantial clinical need for engineered replacements of TA, but data are scarce on the material properties and biochemical composition of healthy TA. The objective of this study was to assess tissue organization, protein content, and mechanical properties of porcine TA to establish structure-function relationships and design criteria for tissue engineering efforts. TA was isolated from six pigs and subjected to histomorphometry, quantification of collagen content and pyridinoline crosslinks, bottom-up proteomics, and tensile mechanical testing. Collagen was 20 ± 2%/wet weight (WW) and 53 ± 4%/dry weight (DW). Pyridinoline content was 426 ±131 ng/mg WW, 1011 ± 190 ng/mg DW, and 45 ± 8 mmol/mol hydroxyproline. Bottom-up proteomics identified 14 proteins with an abundance of >0.1% of total protein. The most abundant collagen subtype was type I, representing 95.5 ± 1.5% of the total protein in the samples. Collagen types III, XII, and VI were quantified at 1.7 ± 1.0%, 0.8 ± 0.2%, and 0.4 ± 0.2%, respectively. Tensile testing revealed anisotropy: Young's modulus was significantly higher longitudinally than circumferentially (60 ± 18 MPa vs. 8 ± 5 MPa, p < 0.01), as was ultimate tensile strength (16 ± 4 MPa vs. 3 ± 3 MPa, p < 0.01). Taken together, the tissue mechanical and compositional data obtained in this study provide important benchmarks for the development of TA biomaterials. STATEMENT OF SIGNIFICANCE: The tunica albuginea of the penis serves an important structural role in physiologic penile erection. This tissue can become damaged by disease or trauma, leading to pain and deformity. Treatment options are limited. Little is known about the precise biochemical composition and biomechanical properties of healthy tunica albuginea. In this study, we characterize the tissue using proteomic analysis and tensile testing to establish design parameters for future tissue engineering efforts. To our knowledge, this is the first study to quantify tissue anisotropy and to use bottom-up proteomics to characterize the composition of penile tunica albuginea.


Assuntos
Induração Peniana , Masculino , Humanos , Animais , Suínos , Anisotropia , Proteômica , Engenharia Tecidual , Pênis/fisiologia , Colágeno , Relação Estrutura-Atividade
18.
Acta Biomater ; 168: 113-124, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37454708

RESUMO

Nose reconstruction often requires scarce cartilage grafts. Nasal cartilage properties must be determined to serve as design criteria for engineering grafts. Thus, mechanical and biochemical properties were obtained in multiple locations of human nasal septum, upper lateral cartilage (ULC), and lower lateral cartilage (LLC). Within each region, no statistical differences among locations were detected, but anisotropy at some septum locations was noted. In the LLC, the tensile modulus and ultimate tensile strength (UTS) in the inferior-superior direction were statistically greater than in the anterior-posterior direction. Cartilage from all regions exhibited hyperelasticity in tension, but regions varied in degree of hyalinicity (i.e., Col II:Col I ratio). The septum contained the most collagen II and least collagen I and III, making it more hyaline than the ULC and LLC. The septum had a greater aggregate modulus, UTS, and lower total collagen/wet weight (Col/WW) than the ULC and LLC. The ULC had greater tensile modulus, DNA/WW, and lower glycosaminoglycan/WW than the septum and LLC. The ULC had a greater pyridinoline/Col than the septum. Histological staining suggested the presence of chondrons in all regions. In the ULC and LLC, tensile modulus correlated with total collagen content, while aggregate modulus correlated with pyridinoline content and weakly with pentosidine content. However, future studies should be performed to validate these proposed structure-function relationships. This study of human nasal cartilage provides 1) crucial design criteria for nasal cartilage tissue engineering efforts, 2) quantification of major and minor collagen subtypes and crosslinks, and 3) structure-function relationships. Surprisingly, the large mechanical properties found, particularly in the septum, suggests that nasal cartilage may experience higher-than-expected mechanical loads. STATEMENT OF SIGNIFICANCE: While tissue engineering holds promise to generate much-needed cartilage grafts for nasal reconstruction, little is known about nasal cartilage from an engineering perspective. In this study, the mechanical and biochemical properties of the septum, upper lateral cartilage (ULC), and lower lateral cartilage (LLC) were evaluated using cartilage-specific methods. For the first time in this tissue, all major and minor collagens and collagen crosslinks were measured, demonstrating that the septum was more hyaline than the ULC and LLC. Additionally, new structure-function relationships in the ULC and LLC were identified. This study greatly expands upon the quantitative understanding of human nasal cartilage and provides crucial engineering design criteria for much-needed nasal cartilage tissue engineering efforts.


Assuntos
Cartilagens Nasais , Engenharia Tecidual , Humanos , Septo Nasal/cirurgia , Colágeno , Relação Estrutura-Atividade
19.
J Dent Sci ; 18(3): 1301-1309, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37404656

RESUMO

Background/purpose: Artificial Intelligence (AI) can optimize treatment approaches in dental healthcare due to its high level of accuracy and wide range of applications. This study seeks to propose a new deep learning (DL) ensemble model based on deep Convolutional Neural Network (CNN) algorithms to predict tooth position, detect shape, detect remaining interproximal bone level, and detect radiographic bone loss (RBL) using periapical and bitewing radiographs. Materials and methods: 270 patients from January 2015 to December 2020, and all images were deidentified without private information for this study. A total of 8000 periapical radiographs with 27,964 teeth were included for our model. AI algorithms utilizing the YOLOv5 model and VIA labeling platform, including VGG-16 and U-Net architecture, were created as a novel ensemble model. Results of AI analysis were compared with clinicians' assessments. Results: DL-trained ensemble model accuracy was approximately 90% for periapical radiographs. Accuracy for tooth position detection was 88.8%, tooth shape detection 86.3%, periodontal bone level detection 92.61% and radiographic bone loss detection 97.0%. AI models were superior to mean accuracy values from 76% to 78% when detection was performed by dentists. Conclusion: The proposed DL-trained ensemble model provides a critical cornerstone for radiographic detection and a valuable adjunct to periodontal diagnosis. High accuracy and reliability indicate model's strong potential to enhance clinical professional performance and build more efficient dental health services.

20.
J Mol Biol ; 435(17): 168184, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37348754

RESUMO

Hsp90 and Hsp70 are highly conserved molecular chaperones that help maintain proteostasis by participating in protein folding, unfolding, remodeling and activation of proteins. Both chaperones are also important for cellular recovery following environmental stresses. Hsp90 and Hsp70 function collaboratively for the remodeling and activation of some client proteins. Previous studies using E. coli and S. cerevisiae showed that residues in the Hsp90 middle domain directly interact with a region in the Hsp70 nucleotide binding domain, in the same region known to bind J-domain proteins. Importantly, J-domain proteins facilitate and stabilize the interaction between Hsp90 and Hsp70 both in E. coli and S. cerevisiae. To further explore the role of J-domain proteins in protein reactivation, we tested the hypothesis that J-domain proteins participate in the collaboration between Hsp90 and Hsp70 by simultaneously interacting with Hsp90 and Hsp70. Using E. coli Hsp90, Hsp70 (DnaK), and a J-domain protein (CbpA), we detected a ternary complex containing all three proteins. The interaction involved the J-domain of CbpA, the DnaK binding region of E. coli Hsp90, and the J-domain protein binding region of DnaK where Hsp90 also binds. Additionally, results show that E. coli Hsp90 interacts with E. coli J-domain proteins, DnaJ and CbpA, and that yeast Hsp90, Hsp82, interacts with a yeast J-domain protein, Ydj1. Together these results suggest that the complexes may be transient intermediates in the pathway of collaborative protein remodeling by Hsp90 and Hsp70.


Assuntos
Proteínas de Escherichia coli , Proteínas de Choque Térmico HSP70 , Proteínas de Choque Térmico HSP90 , Adenosina Trifosfatases/química , Adenosina Trifosfatases/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Domínios Proteicos
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