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1.
J Am Chem Soc ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38855935

RESUMO

Targeted protein degradation (TPD) has emerged as an effective therapeutic strategy for a wide range of diseases; however, the blood-brain barrier (BBB) limits access of degraders into the central nervous system (CNS). Here, we present a new class of bifunctional small molecules, called TransMoDEs (Transcytosis-inducing molecular degraders of extracellular proteins), capable of both (1) removal of target protein via lysosomal proteolysis and (2) transcytosis of protein targets across brain endothelial cells. TransMoDEs are derived from Angiopep-2, a peptide motif previously employed as a covalent tag to facilitate receptor-mediated transcytosis across the BBB. We demonstrate that TransMoDEs containing either a biotin or chloroalkane ligand can trigger endocytosis of streptavidin or HaloTag protein, respectively. Interestingly, although low-density lipoprotein receptor-related protein 1 (LRP1) has been reported as the primary receptor for Angiopep-2, TransMoDE-mediated target uptake does not rely exclusively on this pathway. Furthermore, TransMoDE-mediated endocytosis of streptavidin in a bEnd.3 BBB model occurs in a clathrin-mediated mechanism and results in both lysosomal localization and transcytosis of the target protein. This study demonstrates that TransMoDEs can recruit, transcytose, and degrade proteins of interest in cells relevant to the CNS, supporting their further development for the removal of pathogenic neuroproteins.

2.
Nat Chem Biol ; 17(9): 947-953, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34413525

RESUMO

Targeted protein degradation (TPD) has emerged as a promising therapeutic strategy. Most TPD technologies use the ubiquitin-proteasome system, and are therefore limited to targeting intracellular proteins. To address this limitation, we developed a class of modular, bifunctional synthetic molecules called MoDE-As (molecular degraders of extracellular proteins through the asialoglycoprotein receptor (ASGPR)), which mediate the degradation of extracellular proteins. MoDE-A molecules mediate the formation of a ternary complex between a target protein and ASGPR on hepatocytes. The target protein is then endocytosed and degraded by lysosomal proteases. We demonstrated the modularity of the MoDE-A technology by synthesizing molecules that induce depletion of both antibody and proinflammatory cytokine proteins. These data show experimental evidence that nonproteinogenic, synthetic molecules can enable TPD of extracellular proteins in vitro and in vivo. We believe that TPD mediated by the MoDE-A technology will have widespread applications for disease treatment.


Assuntos
Receptor de Asialoglicoproteína/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Dinitrofenóis/química , Dinitrofenóis/metabolismo , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/química
3.
J Am Chem Soc ; 144(48): 21843-21847, 2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36410375

RESUMO

Pentosinane is a structurally complex nonenzymatic post-translational modification of proteins believed to be present in all living things. It falls into the category of advanced glycation end products (AGEs) and is structurally related to the other AGEs pentosidine and glucosepane. Although pentosidine and glucosepane have been widely studied for their role in wide-ranging conditions (e.g., diabetes mellitus, Alzheimer's disease, and human aging), relatively little is known about pentosinane. Interestingly, previous reports have suggested that pentosidine may derive from pentosinane. The (patho)physiological significance of pentosinane in humans is largely unexplored. As a first step to address this knowledge gap, we report herein the first total synthesis of pentosinane. Our synthesis is high yielding (1.7% over seven steps), concise, and enantioselective, and it leverages a strategy for synthesizing 2,5-diaminoimidazoles previously developed by our lab. Access to synthetic pentosinane has allowed us to perform additional studies showing that its oxidation to pentosidine is both pH and oxygen dependent and is substantially slower under physiological conditions than previously believed. Additionally, pentosinane rapidly decomposes under harshly acidic conditions typically employed for pentosidine isolation. Taken together, these results suggest that pentosinane is likely to be more abundant in vivo than previously appreciated. We believe these results represent a critical step toward illuminating the role(s) of pentosinane in human biology.


Assuntos
Processamento de Proteína Pós-Traducional , Humanos
4.
J Biol Chem ; 295(31): 10562-10571, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32381510

RESUMO

Collagen is a structural protein whose internal cross-linking critically determines the properties and functions of connective tissue. Knowing how the cross-linking of collagen changes with age is key to understanding why the mechanical properties of tissues change over a lifetime. The current scientific consensus is that collagen cross-linking increases with age and that this increase leads to tendon stiffening. Here, we show that this view should be reconsidered. Using MS-based analyses, we demonstrated that during aging of healthy C57BL/6 mice, the overall levels of collagen cross-linking in tail tendon decreased with age. However, the levels of lysine glycation in collagen, which is not considered a cross-link, increased dramatically with age. We found that in 16-week-old diabetic db/db mice, glycation reaches levels similar to those observed in 98-week-old C57BL/6 mice, while the other cross-links typical of tendon collagen either decreased or remained the same as those observed in 20-week-old WT mice. These results, combined with findings from mechanical testing of tendons from these mice, indicate that overall collagen cross-linking in mouse tendon decreases with age. Our findings also reveal that lysine glycation appears to be an important factor that contributes to tendon stiffening with age and in diabetes.


Assuntos
Envelhecimento/metabolismo , Colágeno/metabolismo , Cauda/metabolismo , Tendões/metabolismo , Animais , Glicosilação , Camundongos
5.
Chembiochem ; 22(12): 2102-2106, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33725370

RESUMO

Post-translational modifications (PTMs) play roles in both physiological and pathophysiological processes through the regulation of enzyme structure and function. We recently identified a novel PTM, lactoylLys, derived through a nonenzymatic mechanism from the glycolytic by-product, lactoylglutathione. Under physiologic scenarios, glyoxalase 2 prevents the accumulation of lactoylglutathione and thus lactoylLys modifications. What dictates the site-specificity and abundance of lactoylLys PTMs, however, remains unknown. Here, we report sirtuin 2 as a lactoylLys eraser. Using chemical biology and CRISPR-Cas9, we show that SIRT2 controls the abundance of this PTM both globally and on chromatin. These results address a major gap in our understanding of how nonenzymatic PTMs are regulated and controlled.


Assuntos
Sirtuína 2/metabolismo , Tioléster Hidrolases/metabolismo , Linhagem Celular , Humanos , Modelos Moleculares , Estrutura Molecular , Processamento de Proteína Pós-Traducional , Sirtuína 2/deficiência , Tioléster Hidrolases/deficiência
6.
Proc Natl Acad Sci U S A ; 115(37): 9228-9233, 2018 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-30150385

RESUMO

Histone posttranslational modifications (PTMs) regulate chromatin dynamics, DNA accessibility, and transcription to expand the genetic code. Many of these PTMs are produced through cellular metabolism to offer both feedback and feedforward regulation. Herein we describe the existence of Lys and Arg modifications on histones by a glycolytic by-product, methylglyoxal (MGO). Our data demonstrate that adduction of histones by MGO is an abundant modification, present at the same order of magnitude as Arg methylation. These modifications were detected on all four core histones at critical residues involved in both nucleosome stability and reader domain binding. In addition, MGO treatment of cells lacking the major detoxifying enzyme, glyoxalase 1, results in marked disruption of H2B acetylation and ubiquitylation without affecting H2A, H3, and H4 modifications. Using RNA sequencing, we show that MGO is capable of altering gene transcription, most notably in cells lacking GLO1. Finally, we show that the deglycase DJ-1 protects histones from adduction by MGO. Collectively, our findings demonstrate the existence of a previously undetected histone modification derived from glycolysis, which may have far-reaching implications for the control of gene expression and protein transcription linked to metabolism.


Assuntos
Arginina/metabolismo , Histonas/metabolismo , Lactoilglutationa Liase/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Aldeído Pirúvico , Transcrição Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Aldeído Pirúvico/metabolismo , Aldeído Pirúvico/farmacologia
7.
Biomacromolecules ; 21(2): 793-802, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-31829561

RESUMO

Synthetic materials capable of engineering the immune system are of great relevance in the fight against cancer to replace or complement the current monoclonal antibody and cell therapy-based immunotherapeutics. Here, we report on antibody recruiting glycopolymers (ARGPs). ARGPs consist of polymeric copies of a rhamnose motif, which can bind endogenous antirhamnose antibodies present in human serum. As a proof-of-concept, we have designed ARGPs with a lipophilic end group that efficiently inserts into cell-surface membranes. We validate the specificity of rhamnose to attract antibodies from human serum to the target cell surface and demonstrate that ARGPs outperform an analogous small-molecule compound containing only one single rhamnose motif. The ARGP concept opens new avenues for the design of potent immunotherapeutics that mark target cells for destruction by the immune system through antibody-mediated effector functions.


Assuntos
Anticorpos Monoclonais/metabolismo , Formação de Anticorpos/fisiologia , Polímeros/metabolismo , Receptores de Superfície Celular/metabolismo , Ramnose/metabolismo , Adolescente , Adulto , Idoso , Anticorpos Monoclonais/química , Linhagem Celular Tumoral , Feminino , Humanos , Células Jurkat , Masculino , Pessoa de Meia-Idade , Polímeros/química , Ligação Proteica/fisiologia , Receptores de Superfície Celular/química , Ramnose/química , Adulto Jovem
8.
J Pediatr Orthop ; 40(1): 1-7, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31815855

RESUMO

BACKGROUND: Systemic inflammatory response syndrome (SIRS) is a well-recognized phenomenon in adult trauma populations. The "initial hit" of the traumatic event is often coupled with a systemic immune response characterized by changes in vital signs and laboratory indicators. A "second hit" from surgery during this time frame often results in acute lung injury, along with deterioration of the patient's clinical condition. We hypothesized that children and adolescents would experience SIRS physiology, but would not experience adult respiratory distress syndrome (ARDS) or "second hit" related death to the extent seen in the adult populations. METHODS: We queried the trauma database of our level 1 pediatric trauma center from January 2005 to December 2015 for patients with injury severity scores of >16. We used the electronic medical record to track SIRS criteria in patients days 1 to 4 posttrauma. Trends were examined in patients with an orthopaedic injury (OI) and with no orthopaedic injury. Patients were further subcategorized and analyzed by age group based on the convention for definition of pediatric SIRS. Patients in the orthopaedic cohort were further examined for pulmonary complications and death. Logistic regression was used to identify risk factors for SIRS physiology in the first 4 days of hospitalization. RESULTS: 81.4% (OI) and 69.1% no orthopaedic injury reached the threshold for SIRS within their first 4 days of hospitalization. Nine patients died in the hospital. Only 3 OI patients developed the criteria for ARDS, and only 3 patients with orthopaedic injuries died, 2 died within 24 hours of presentation and 1 within 48 hours, all had severe brain trauma. Increasing age groups showed increasing proportion of patients with SIRS. Increasing injury severity score and increasing age were independent predictors of SIRS during days 1 to 4. DISCUSSION: SIRS seems to be as common in children as the reported rates for adults, and the proportion of SIRS in children increases with increasing age and injury severity. The high mortality rate and rate of ARDS observed in adults was not observed in our cohort. The presence or absence of major orthopaedic injuries was not a significant predictor. The SIRS response in polytraumatized children is poorly understood. The clinical phenomenon of acute lung injury/ARDS is observed less often in children, but the exact mechanism by which this occurs is unknown. LEVEL OF EVIDENCE: Level III-case control.


Assuntos
Osso e Ossos/lesões , Traumatismo Múltiplo/fisiopatologia , Traumatismo Múltiplo/cirurgia , Sistema Musculoesquelético/lesões , Síndrome do Desconforto Respiratório/etiologia , Síndrome de Resposta Inflamatória Sistêmica/fisiopatologia , Adolescente , Fatores Etários , Estudos de Casos e Controles , Criança , Pré-Escolar , Registros Eletrônicos de Saúde , Mortalidade Hospitalar , Humanos , Escala de Gravidade do Ferimento , Traumatismo Múltiplo/complicações , Estudos Retrospectivos , Síndrome de Resposta Inflamatória Sistêmica/etiologia
9.
J Pediatr Orthop ; 40(10): e927-e931, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804865

RESUMO

BACKGROUND: Acute posterior sternoclavicular dislocations (APSCD) are rare injuries that historically have prompted concern for injury to the great vessels and other mediastinal structures from initial trauma or subsequent treatment, resulting in the recommendation that a thoracic or vascular surgeon be present or available during operative treatment. The objectives of the study were to characterize the demographic, clinical, and radiographic characteristics of a large series of APSCDs in skeletally immature patients and to describe the rate and nature of any vascular or mediastinal complications that occurred during treatment. METHODS: Following Institutional Review Board approval, records of consecutive patients under 25 years of age treated for APSCD were collected from each of 6 participating centers. Only acute injuries (sustained fewer than 10 days before presentation) were included. Patient demographics, injury mechanism, associated mediastinal injuries, and need for thoracic/vascular surgery were recorded. Mediastinal structures injured or compressed by mass effect were specifically characterized by review of preoperative computed tomography imaging. RESULTS: Review identified 125 patients with a mean age of 14.7 years; 88% were male. APSCD most commonly resulted from a sporting injury (74%) followed by falls from standing height (10%) and high-energy motor vehicle trauma (10%). The most common finding on cross-sectional imaging was compression without laceration of the ipsilateral brachiocephalic vein (50%). Eleven patients had successful closed reduction, and 114 (90%) had open reduction and internal fixation, with 25 failed or unstable closed reductions preceding open treatment. There were no vascular or mediastinal injuries during reduction or fixation that required intervention. CONCLUSIONS: In this multicenter series of 125 APSCDs no injuries to the great vessels/mediastinal structures requiring intervention were identified. Although more than half of patients had evidence of extrinsic vascular compression at the time of injury, careful open reduction of acute injuries can be safely performed. Although vascular injuries following APSCD seem to be quite rare, vascular complications can be catastrophic. Treating providers should consider these data and their own institutional resources to maximize patient safety during the treatment of APSCD. LEVEL OF EVIDENCE: Level III-therapeutic case control study.


Assuntos
Luxações Articulares/complicações , Mediastino/lesões , Articulação Esternoclavicular/lesões , Lesões do Sistema Vascular/etiologia , Acidentes por Quedas , Adolescente , Criança , Pré-Escolar , Feminino , Fixação Interna de Fraturas , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Estudos Retrospectivos , Adulto Jovem
10.
Chembiochem ; 20(18): 2402-2410, 2019 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-31013547

RESUMO

Advanced glycation end products (AGEs) are a heterogeneous group of molecules that emerge from the condensation of sugars and proteins through the Maillard reaction. Despite a significant number of studies showing strong associations between AGEs and the pathologies of aging-related illnesses, it has been a challenge to establish AGEs as causal agents primarily due to the lack of tools in reversing AGE modifications at the molecular level. Herein, we show that MnmC, an enzyme involved in a bacterial tRNA-modification pathway, is capable of reversing the AGEs carboxyethyl-lysine (CEL) and carboxymethyl-lysine (CML) back to their native lysine structure. Combining structural homology analysis, site-directed mutagenesis, and protein domain dissection studies, we generated a variant of MnmC with improved catalytic properties against CEL in its free amino acid form. We show that this enzyme variant is also active on a CEL-modified peptidomimetic and an AGE-containing peptide that has been established as an authentic ligand of the receptor for AGEs (RAGE). Our data demonstrate that MnmC variants are promising lead catalysts toward the development of AGE-reversal tools and a better understanding of AGE biology.


Assuntos
Proteínas de Escherichia coli/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Complexos Multienzimáticos/metabolismo , Biocatálise , Escherichia coli/enzimologia , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Cinética , Lisina/análogos & derivados , Lisina/metabolismo , Complexos Multienzimáticos/química , Complexos Multienzimáticos/genética , Mutação , Engenharia de Proteínas , Especificidade por Substrato
11.
Clin Orthop Relat Res ; 477(1): 10-21, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30179955

RESUMO

BACKGROUND: Cerebral palsy (CP) comprises a heterogeneous group of disorders whose clinical manifestations and epidemiologic characteristics vary across socioeconomic and geographic contexts. The functional severity of untreated CP in low-income countries has been insufficiently studied; a better understanding of how these children present for care in resource-constrained environments is important because it will better characterize the natural history of CP, guide clinical decision-making, and aid in the prognostication of children with untreated CP. QUESTIONS/PURPOSES: The purposes of this study were (1) to determine the etiologies, motor subtypes, topographic distributions, and functional classifications of a large cohort of Nepali children with untreated CP presenting to a large pediatric rehabilitation center in Nepal; and (2) to compare the Gross Motor Function Classification System (GMFCS), the Manual Ability Classification System (MACS), and the Communication Function Classification System (CFCS) scores of a subset of patients with spastic CP in the Nepali cohort with control subjects from high-income countries. METHODS: A cross-sectional study was conducted at the Hospital and Rehabilitation Centre for Disabled Children in Nepal. Two hundred six consecutive Nepali children (76 girls; median age 4.0 years [interquartile range {IQR}, 2.5-9.0 years]) were evaluated to determine the demographic, clinical, and functional characteristics of a cohort of Nepali children with untreated CP. A systematic review of the Medline and Cochrane databases was then performed to obtain reference classification scores from high-income countries. Cross-sectional, noninterventional studies reporting at least one functional classification system with a sample size of at least 50 participants were included. Only studies of patients with spastic CP were included to allow for compatible comparisons with a subset of our study sample with spastic CP. A random-effects analysis was used to pool functional scores from participants in the included studies. Among the 206 children in our sample, 102 had spastic CP (35 girls; median age 5.5 years [IQR, 3.5-9.0 years]). Functional scores from these children were compared with pooled scores obtained from the systematic review by assessing the proportions of children in each sample with GMFCS, MACS, and CFCS score categories of I or II versus III to V. RESULTS: Children with spastic hemiplegia from high-income countries were more likely to have a GMFCS score of I or II (96% [95% confidence interval {CI}, 92%-99%] versus 78% [95% CI, 62%-89%]) and a MACS score of I or II (83% [95% CI, 77%-88%] versus 50% [95% CI, 32%-68%]) relative to those from Nepal, but they were less likely to have a CFCS score of I or II (67% [95% CI, 51%-80%] versus 97% [95% CI, 87%-99%]). No differences were seen in children with spastic diplegia or quadriplegia. CONCLUSIONS: Children in Nepal with hemiplegic CP display less difficulty in communicating and social engagement (CFCS) despite more-severe upper- and lower-extremity impairments in gross motor function (GMFCS) and manual ability (MACS) than do children with hemiplegic CP from high-income countries. Targeted interventions, including perhaps simple orthopaedic interventions to treat soft-tissue contractures, may therefore provide more-substantial improvements in function and quality of life to Nepali children than could be achieved for the same deployment of resources in more-affluent settings. LEVEL OF EVIDENCE: Level II, prognostic study.


Assuntos
Paralisia Cerebral/diagnóstico , Paralisia Cerebral/epidemiologia , Países em Desenvolvimento , Disparidades nos Níveis de Saúde , Atividade Motora , Fatores Socioeconômicos , Adolescente , Desenvolvimento do Adolescente , Fatores Etários , Paralisia Cerebral/fisiopatologia , Paralisia Cerebral/reabilitação , Criança , Desenvolvimento Infantil , Pré-Escolar , Estudos Transversais , Avaliação da Deficiência , Feminino , Disparidades em Assistência à Saúde , Humanos , Lactente , Masculino , Nepal/epidemiologia , Prognóstico , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença
12.
J Pediatr Orthop ; 39(5): 268-274, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30969258

RESUMO

BACKGROUND: The management of septic arthritis of the hip in children can be complicated by the presence of additional coexisting periarticular infections (PAIs). Criteria predicting the presence of PAI have recently been proposed by Rosenfeld and colleagues with the goal of using magnetic resonance imaging (MRI) efficiently in the workup of septic arthritis. The purpose of this study was to determine the applicability of recently published predictive criteria for PAI (developed in the Southwestern United States using a variety of joints) to septic arthritis of the hip treated at a large Northeastern tertiary care center. METHODS: We studied patients treated for septic arthritis of the hip with irrigation and debridement in a large Northeastern tertiary care center over a 10-year period. Laboratory and clinical variables related to presentation, treatment, and outcome were collected. Subjects with and without a perioperative MRI were compared with published criteria by Rosenfeld and colleagues. RESULTS: Fifty-one subjects (53 hips) were identified with a mean age of 7.0 years (range, 1.2 to 19.3 y) and mean follow-up was 16 months (range, 2 to 85 mo). MRIs were obtained in 20 subjects (43%). Coexisting osteomyelitis was revealed in 7/20 of these studies (35% of MRIs); 4 of which showed coexisting intramuscular abscesses. Within our MRI cohort, the Rosenfeld criteria were found to have a sensitivity of 86%, a specificity of 54%, and a false-positive rate of 50% for the hip (compared with originally reported sensitivity of 90%, specificity of 67%, and false-positive rate of 33%). Overall, advanced imaging changed management in 5/51 patients (9%) by influencing the need for further treatment, whereas the remainder underwent isolated treatment of the septic hip joint with no adverse outcomes. One patient in the MRI cohort (without PAI) developed osteonecrosis of the femoral head. CONCLUSIONS: We found lower sensitivity and specificity and higher false-positive rates for the Rosenfeld criteria in the hip for our geographically distinct population. Using the Rosenfeld criteria, MRIs would have been ordered unnecessarily in half of our series. Because of potential differences in regional microbiology and anatomic-specific factors, general predictive criteria for coexisting PAI based a single geographic region may be less generalizable to cases of hip sepsis in other geographic areas such as the Northeastern United States. LEVEL OF EVIDENCE: Level 4-retrospective cohort study.


Assuntos
Artrite Infecciosa/complicações , Articulação do Quadril , Artropatias/diagnóstico , Adolescente , Adulto , Artrite Infecciosa/terapia , Criança , Pré-Escolar , Comorbidade , Desbridamento/métodos , Feminino , Articulação do Quadril/microbiologia , Articulação do Quadril/cirurgia , Humanos , Lactente , Imageamento por Ressonância Magnética/normas , Masculino , Osteomielite/complicações , Osteonecrose/etiologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Irrigação Terapêutica , Adulto Jovem
13.
J Pediatr Orthop ; 39(9): e674-e679, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31503223

RESUMO

BACKGROUND: Our goal is to correlate the findings on flexion and extension radiographs with dynamic magnetic resonance imaging (MRI), and the clinical history, in a nonrandomly selected cohort of patients with 22q11.2 deletion syndrome (22q). METHODS: All patients with the 22q who had a dynamic MRI from January 2004 to March 2015 were included. We analyzed multiple radiographic measurements on both the dynamic plain films and the MRIs, and correlated these findings with a review of each patient's medical record. RESULTS: Multiple congenital anomalies were identified as noted in previous studies, and 61% of the patients had a failure of fusion of the anterior (n=2, 9%), posterior (n=2, 9%), or anterior and posterior arches (n=10, 43%). Quantitative measurements were impossible to report with certainty because of the upper cervical anomalies, and no cases of instability were identified using a qualitative assessment. We identified spinal cord encroachment (30%) and impingement (18%); however, none of the patients had any signal change in their spinal cord. None of these findings could be definitively correlated with any clinical symptoms. A single patient was diagnosed with a Chiari I malformation, while another had cerebellar ectopia. CONCLUSIONS: Although the upper cervical anomalies are extremely common in 22q, we did not identify cases of instability on dynamic plain radiographs and MRI. Although our findings do not support routine screening with flexion and extension MRI, this study may be required in patients with neurological symptoms and/or findings or abnormalities on dynamic plain radiographs. LEVEL OF EVIDENCE: Level III.


Assuntos
Vértebras Cervicais/diagnóstico por imagem , Síndrome de DiGeorge/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Anormalidades Múltiplas , Adolescente , Adulto , Aracnodactilia , Criança , Pré-Escolar , Craniossinostoses , Humanos , Síndrome de Marfan , Radiografia , Amplitude de Movimento Articular , Estudos Retrospectivos , Medula Espinal , Adulto Jovem
14.
Angew Chem Int Ed Engl ; 58(52): 18913-18917, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31713976

RESUMO

Here we describe a general method for the synthesis of 2,5-diaminoimidazoles, which involves a thermal reaction between α-aminoketones and substituted guanylhydrazines without the need for additives. As one of the few known ways to access the 2,5-diaminoimidazole motif, our method greatly expands the number of reported diaminoimidazoles and further supports our previous observations that these compounds spontaneously adopt the non-aromatic 4(H) tautomer. The reaction works successfully on both cyclic and acyclic amino ketone starting materials, as well as a range of substituted guanylhydrazines. Following optimization, the method was applied to the efficient synthesis of the advanced glycation end product (AGE) methylglyoxal-derived imidazolium crosslink (MODIC). We expect that this method will enable rapid access to a variety of biologically important 2,5-diaminoimidazole-containing products.

15.
World J Surg ; 42(10): 3081-3088, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29696326

RESUMO

BACKGROUND: The global burden of musculoskeletal disease and resulting disability is enormous and is expected to increase over the next few decades. In the world's poorest regions, the paucity of information defining and quantifying the current state of access to orthopaedic surgical care is a major problem in developing effective solutions. This study estimates the number of individuals in Northern Tanzania without adequate access to orthopaedic surgical services. METHODS: A chance tree was created to model the probability of access to orthopaedic surgical services in the Northern Tanzanian regions of Arusha, Kilimanjaro, Tanga, Singida, and Manyara, with respect to four dimensions: timeliness, surgical capacity, safety, and affordability. Timeliness was estimated by the proportion of people living within a 4-h driving distance from a hospital with an orthopaedic surgeon, capacity by comparing number of surgeries performed to the number of surgeries indicated, safety by applying WHO Emergency and Essential Surgical Care infrastructure and equipment checklists, and affordability by approximating the proportion of the population protected from catastrophic out-of-pocket healthcare expenditure. We accounted for uncertainty in our model with one-way and probabilistic sensitivity analyses. Data sources included the Tanzanian National Bureau of Statistics and Ministry of Finance, World Bank, World Health Organization, New Zealand Ministry of Health, Google Corporation, NASA population estimator, and 2015 hospital records from Kilimanjaro Christian Medical Center, Machame Hospital, Nkoroanga Hospital, Mt. Meru Hospital, and Arusha Lutheran Medical Center. RESULTS: Under the most conservative assumptions, more than 90% of the Northern Tanzanian population does not have access to orthopaedic surgical services. CONCLUSION: There is a near absence of access to orthopaedic surgical care in Northern Tanzania. These findings utilize more precise country and region-specific data and are consistent with prior published global trends regarding surgical access in Sub-Saharan Africa. As the global health community must develop innovative solutions to address the rising burden of musculoskeletal disease and support the advancement of universal health coverage, increasing access to orthopaedic surgical services will play a central role in improving health care in the world's developing regions.


Assuntos
Gastos em Saúde , Acessibilidade aos Serviços de Saúde , Procedimentos Ortopédicos , Atenção à Saúde , Geografia , Saúde Global , Custos de Cuidados de Saúde , Hospitais , Humanos , Doenças Musculoesqueléticas/terapia , Segurança do Paciente , Probabilidade , Sensibilidade e Especificidade , Tanzânia/epidemiologia , Incerteza
16.
J Pediatr Orthop ; 38(7): 345-349, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27379781

RESUMO

BACKGROUND: Although many studies have separately investigated the treatment of developmental dysplasia of the hip and spastic hip disease, little data exist regarding the treatment of infants with dislocated hips and underlying spasticity. The purpose of this study was to review our results after the surgical treatment of these infants. METHODS: We retrospectively reviewed all children below 3 years of age who underwent hip reconstruction for dislocated hips in the setting of cerebral palsy or other spastic/high-tone neuromuscular disease. Medical records were reviewed for clinical data including treatment course, complications, and need for further surgery. Preoperative and postoperative radiographs were used to determine International Hip Dysplasia Institute (IHDI) grade of dislocation, acetabular index, migration percentage, and presence of avascular necrosis according to the Salter criteria. RESULTS: Eleven patients with 15 hips met our inclusion criteria with a mean age of 20±8 (range, 6 to 34) months. Preoperatively, 12 of 15 hips (80%) were IHDI grade 4 and 3 of 15 (20%) were IHDI grade 3. Mean acetabular index was 29±8 (range, 19 to 46) degrees. Patients underwent open reduction (15 hips), adductor tenotomy (14 hips), femoral osteotomy (10 hips), and pelvic osteotomy (12 hips). At a mean follow-up of 40±16 (range, 13 to 71) months, 13 of 15 hips were IHDI grade 1 (86.7%), 1 was IHDI grade 2 (6.7%), and 1 hip was IHDI grade 3 (6.7%). The mean postoperative migration index was 7%±24% (range, -30% to 46%); the mean acetabular index was 22±8 (range, 9 to 38) degrees. No patients developed radiographically significant osteonecrosis. Complications included 2 femur fractures (13.3%) and 1 symptomatic implant that required early removal. One patient underwent further reconstructive hip surgery. CONCLUSIONS: In this series of infants with hip dislocations and underlying spasticity, open reduction±pelvic osteotomy and/or femoral osteotomy has a nearly 90% success rate in achieving and maintaining adequate hip reduction at intermediate-term follow-up. In the unique population of infants with dislocated hips and underlying spasticity, comprehensive hip reconstruction is largely successful with an acceptable rate of complications. LEVEL OF EVIDENCE: Level IV-retrospective.


Assuntos
Luxação do Quadril/cirurgia , Redução Aberta/estatística & dados numéricos , Osteotomia/estatística & dados numéricos , Paralisia Cerebral/complicações , Pré-Escolar , Feminino , Luxação do Quadril/complicações , Luxação do Quadril/diagnóstico por imagem , Humanos , Lactente , Masculino , Espasticidade Muscular/complicações , Radiografia , Estudos Retrospectivos , Resultado do Tratamento
17.
Angew Chem Int Ed Engl ; 57(7): 1991-1994, 2018 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-29286556

RESUMO

Described herein is a synthetic strategy for the total synthesis of (±)-phomoidride D. This highly efficient and stereoselective approach provides rapid assembly of the carbocyclic core by way of a tandem phenolic oxidation/intramolecular Diels-Alder cycloaddition. A subsequent SmI2 -mediated cyclization cascade delivers an isotwistane intermediate poised for a Wharton fragmentation that unveils the requisite bicyclo[4.3.1]decene skeleton and sets the stage for synthesis completion.


Assuntos
Anidridos Maleicos/síntese química , Compostos Bicíclicos com Pontes/química , Ciclização , Reação de Cicloadição , Oxirredução , Estereoisomerismo
19.
J Pediatr Orthop ; 37(2): e134-e139, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26919713

RESUMO

BACKGROUND: Use of the minimally invasive Ponseti method has been increasing in low and middle-income countries, where most of the world's children with clubfoot are born. This method requires a system of service delivery involving screening, serial casting with or without a tenotomy to achieve correction, and long-term use of an orthosis to maintain correction. The goal of this systematic review is to evaluate the barriers to service delivery and the solutions that have been proposed or implemented to address these barriers. METHODS: A literature search of Medline, Embase, and SCOPUS produced 3251 results. Twenty-four papers were selected for final review. Barriers and their attempted solutions were organized into a previously described health barrier model. We reported on high-impact, sustainable solutions that are feasible for organizations to implement, as opposed to solutions that require major policy or country-wide infrastructure changes. RESULTS: Common barriers found to have the most impact on patient care included financial constraints, transportation, difficulties with brace and cast care, self-perceived health status, lack of physical resources, and provider's lack of knowledge and skill. The most common solutions detailed were education of the provider or patient and financial assistance for patients. CONCLUSIONS: Recognizing that contextually relevant solutions to the challenges of setting up a system for clubfoot service delivery are required, several common barriers have emerged within this systematic review of papers from multiple countries, including spatial accessibility, affordability, and availability. Programs can best prepare for challenges by placing clinics close to population centers and/or allocating funds to subsidize transportation, ensuring that an adequate supply of materials are available for the casting and tenotomy, and enhancing the education of families and health providers. Strengthening communication and establishing partnerships between individuals and organizations promoting the Ponseti method will improve systems for service delivery. LEVEL OF EVIDENCE: Level IV-prognostic study.


Assuntos
Pé Torto Equinovaro/terapia , Países em Desenvolvimento , Acessibilidade aos Serviços de Saúde , Braquetes , Moldes Cirúrgicos , Competência Clínica , Pé Torto Equinovaro/economia , Atenção à Saúde/organização & administração , Custos de Cuidados de Saúde , Nível de Saúde , Humanos , Autocuidado , Meios de Transporte
20.
Angew Chem Int Ed Engl ; 56(42): 13036-13040, 2017 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-28793176

RESUMO

Systemic fungal infections represent an important public health concern, and new antifungal agents are highly desirable. Herein, we describe the design, synthesis, and biological evaluation of a novel class of antifungal compounds called antibody-recruiting molecules targeting fungi (ARM-Fs). Our approach relies on the use of non-peptidic small molecules, which selectively bind fungal cells and recruit endogenous antibodies to their surfaces, resulting in immune-mediated clearance. Using the opportunistic fungal pathogen Candida albicans as a model, we identified a highly specific bifunctional molecule able to mediate the engulfment and phagocytosis of C. albicans cells by human immune cells in biologically relevant functional assays. This work represents a novel therapeutic approach to treating fungal illness with significant potential to complement and/or combine with existing treatment strategies.


Assuntos
Anticorpos/imunologia , Subpopulações de Linfócitos B/imunologia , Candida albicans/imunologia , Acetilglucosamina/química , Anticorpos/metabolismo , Subpopulações de Linfócitos B/citologia , Candida albicans/metabolismo , Candida albicans/patogenicidade , Quitina/química , Quitina/metabolismo , Dinitrobenzenos/química , Dinitrobenzenos/imunologia , Desenho de Fármacos , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Células HL-60 , Interações Hospedeiro-Patógeno , Humanos , Fagocitose
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