RESUMO
Network oscillations across and within brain areas are critical for learning and performance of memory tasks. While a large amount of work has focused on the generation of neural oscillations, their effect on neuronal populations' spiking activity and information encoding is less known. Here, we use computational modeling to demonstrate that a shift in resonance responses can interact with oscillating input to ensure that networks of neurons properly encode new information represented in external inputs to the weights of recurrent synaptic connections. Using a neuronal network model, we find that due to an input current-dependent shift in their resonance response, individual neurons in a network will arrange their phases of firing to represent varying strengths of their respective inputs. As networks encode information, neurons fire more synchronously, and this effect limits the extent to which further "learning" (in the form of changes in synaptic strength) can occur. We also demonstrate that sequential patterns of neuronal firing can be accurately stored in the network; these sequences are later reproduced without external input (in the context of subthreshold oscillations) in both the forward and reverse directions (as has been observed following learning in vivo). To test whether a similar mechanism could act in vivo, we show that periodic stimulation of hippocampal neurons coordinates network activity and functional connectivity in a frequency-dependent manner. We conclude that resonance with subthreshold oscillations provides a plausible network-level mechanism to accurately encode and retrieve information without overstrengthening connections between neurons.
Assuntos
Potenciais de Ação/fisiologia , Aprendizagem/fisiologia , Modelos Neurológicos , Rede Nervosa/fisiologia , Redes Neurais de Computação , Neurônios/fisiologia , Rodopsina/fisiologia , Animais , Simulação por Computador , Canais Iônicos/fisiologia , CamundongosRESUMO
PURPOSE: To understand if anatomic physeal-sparing ACL reconstruction in the immature host preserves range of motion, permits a return to sports, and avoids limb length discrepancy and accelerated intra-articular degeneration with a cross-sectional radiographic, physical examination and patient-reported outcomes analysis. METHODS: A cross-sectional recall study included 38 patients aged 7-15 who underwent all-epiphyseal ACL reconstruction with hamstring allograft performed by a single surgeon at a large academic medical center. All-epiphyseal reconstructions were performed using a modified Anderson physeal-sparing technique, with the femoral tunnel placed using an "inside-out" technique. Assessments consisted of a physical exam, long leg cassette radiographs, KT-1000 measurements, subjective patient metrics, and magnetic resonance imaging. RESULTS: Thirty-eight (56.7%) of 66 eligible patients returned for in-person clinical and radiographic exams. Patients were 11.4 ± 1.8 years at the time of surgery. Five patients were females (13.2%). Mean follow-up was 5.5 ± 2.4 years. ACL re-injuries occurred in four patients (10.5%), all of whom underwent revision reconstructions. Thirty-three of the remaining 34 (97.1%) patients returned to sports following their reconstruction, and 24 (70.6%) returned to their baseline level of competition. Mean limb length discrepancy (LLD) was 0.2 ± 1.4 cm. Nine patients had an LLD of > 1 cm (26.5%), which occurred at an equivalent age as those with < 1 cm LLD (10.8 ± 2.0 vs. 11.7 ± 1.7, n.s.). Pre-operative Marx scores (13.1 ± 3.5) were not significantly different from post-operative values (12.3 ± 5.1, n.s.). Patients who required ACL revisions had significantly lower Marx scores than those with intact primary grafts (8.3 ± 7.1 vs. 13.4 ± 4.5, p = 0.047). Cohort mean International Knee Documentation Committee (IKDC) score was 89.7 ± 12.7. CONCLUSION: Anatomic all-epiphyseal anatomic ACL reconstruction appears to be useful in patients with significant projected remaining growth, with good return-to-sport outcomes and minimal risk of clinically significant physeal complications. However, given the limited patient recall possible in the present study, further large sample size, high-quality works are necessary to validate our findings. LEVEL OF EVIDENCE: Level IV.
Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Lesões do Ligamento Cruzado Anterior/cirurgia , Estudos Transversais , Feminino , Seguimentos , Humanos , Estudos Retrospectivos , Volta ao Esporte , Resultado do TratamentoRESUMO
AIMS: Oral itraconazole has variable pharmacokinetics and risks of adverse events associated with high plasma exposure. An inhalation formulation of itraconazole (PUR1900) is being developed to treat allergic bronchopulmonary aspergillosis, an allergic inflammatory disease occurring in asthmatics and patients with cystic fibrosis. METHODS: A 3-part, open-label Phase 1 study was conducted to evaluate safety, tolerability and pharmacokinetics of PUR1900. Healthy volunteers (n = 5-6/cohort) received either single (Part 1) or multiple (Part 2) ascending doses of PUR1900 for up to 14 days. In Part 3 stable, adult asthmatics received a single dose of 20 mg PUR1900 or 200 mg of oral Sporanox (itraconazole oral solution) in a 2-period randomized cross-over design. Itraconazole plasma and sputum concentrations were evaluated. RESULTS: None of the adverse events considered as at least possibly related to study treatment were moderate or severe, and none were classed as serious. The most common was the infrequent occurrence of mild cough. Itraconazole plasma exposure increased with increasing doses of PUR1900. After 14 days, PUR1900 resulted in plasma exposure (area under the concentration-time curve up to 24 h) 106- to 400-fold lower across doses tested (10-35 mg) than steady-state exposure reported for oral Sporanox 200 mg. In asthmatics, PUR1900 geometric mean maximum sputum concentrations were 70-fold higher and geometric mean plasma concentrations were 66-fold lower than with oral Sporanox. CONCLUSION: PUR1900 was safe and well-tolerated under the study conditions. Compared to oral dosing, PUR1900 achieved higher lung and lower plasma exposure. The pharmacokinetic profile of PUR1900 suggests the potential to improve upon the efficacy and safety profile observed with oral itraconazole.
Assuntos
Itraconazol , Administração Oral , Adulto , Área Sob a Curva , Estudos de Coortes , Estudos Cross-Over , Voluntários Saudáveis , Humanos , Itraconazol/efeitos adversosRESUMO
Familial cerebral cavernous malformations type III (fCCM3) is a disease of the cerebrovascular system caused by loss-of-function mutations in ccm3 that result in dilated capillary beds that are susceptible to hemorrhage. Before hemorrhage, fCCM3 lesions are characterized by a hyperpermeable blood-brain barrier (BBB), the key pathologic feature of fCCM3. We demonstrate that connexin 43 (Cx43), a gap junction (GJ) protein that is incorporated into the BBB junction complex, is up-regulated in lesions of a murine model of fCCM3. Small interfering RNA-mediated ccm3 knockdown (CCM3KD) in brain endothelial cells in vitro increased Cx43 protein expression, GJ plaque size, GJ intracellular communication (GJIC), and barrier permeability. CCM3KD hyperpermeability was rescued by GAP27, a peptide gap junction and hemichannel inhibitor of Cx43 GJIC. Tight junction (TJ) protein, zonula occludens 1 (ZO-1), accumulated at Cx43 GJs in CCM3KD cells and displayed fragmented staining at TJs. The GAP27-mediated inhibition of Cx43 GJs in CCM3KD cells restored ZO-1 to TJ structures and reduced plaque accumulation at Cx43 GJs. The TJ protein, Claudin-5, was also fragmented at TJs in CCM3KD cells, and GAP27 treatment lengthened TJ-associated fragments and increased Claudin 5-Claudin 5 transinteraction. Overall, we demonstrate that Cx43 GJs are aberrantly increased in fCCM3 and regulate barrier permeability by a TJ-dependent mechanism.-Johnson, A. M., Roach, J. P., Hu, A., Stamatovic, S. M., Zochowski, M. R., Keep, R. F., Andjelkovic, A. V. Connexin 43 gap junctions contribute to brain endothelial barrier hyperpermeability in familial cerebral cavernous malformations type III by modulating tight junction structure.
Assuntos
Barreira Hematoencefálica/metabolismo , Conexina 43/metabolismo , Endotélio Vascular/metabolismo , Junções Comunicantes/metabolismo , Hemangioma Cavernoso do Sistema Nervoso Central/metabolismo , Junções Íntimas/metabolismo , Animais , Barreira Hematoencefálica/patologia , Linhagem Celular , Claudina-5/genética , Claudina-5/metabolismo , Conexina 43/genética , Modelos Animais de Doenças , Endotélio Vascular/patologia , Junções Comunicantes/genética , Junções Comunicantes/patologia , Hemangioma Cavernoso do Sistema Nervoso Central/genética , Hemangioma Cavernoso do Sistema Nervoso Central/patologia , Humanos , Camundongos , Camundongos Knockout , Permeabilidade , Junções Íntimas/genética , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
LESSONS LEARNED: Despite the compelling preclinical rationale of evaluating the genetically engineered heparin derivative, necuparanib, combined with standard therapy in metastatic pancreas adenocarcinoma, the results were ultimately disappointing.Safety was documented, although dose escalation was limited by the number of subcutaneous injections, the potential for skin toxicity (cellulitis), and low-level anticoagulant effect. Nonetheless, the hypothesis of targeting prothrombotic pathways in pancreas adenocarcinoma remains compelling. BACKGROUND: Necuparanib is derived from unfractionated heparin and engineered for reduced anticoagulant activity while preserving known heparin-associated antitumor properties. This trial assessed the safety, pharmacokinetics (PK), pharmacodynamics, and initial efficacy of necuparanib combined with gemcitabine ± nab-paclitaxel in patients with metastatic pancreatic cancer. METHODS: Patients received escalating daily subcutaneous doses of necuparanib plus 1,000 mg/m2 gemcitabine (days 1, 8, 15, and every 28 days). The protocol was amended to include 125 mg/m2 nab-paclitaxel after two cohorts (following release of the phase III MPACT data). The necuparanib starting dose was 0.5 mg/kg, with escalation via a modified 3 + 3 design until the maximum tolerated dose (MTD) was determined. RESULTS: Thirty-nine patients were enrolled into seven cohorts (necuparanib 0.5, 1 mg/kg + gemcitabine; necuparanib 1, 2, 4, 6, and 5 mg/kg + nab-paclitaxel + gemcitabine). The most common adverse events were anemia (56%), fatigue (51%), neutropenia (51%), leukopenia (41%), and thrombocytopenia (41%). No deaths and two serious adverse events were potentially related to necuparanib. Measurable levels of necuparanib were seen starting at the 2 mg/kg dose. Of 24 patients who received at least one dose of necuparanib + nab-paclitaxel + gemcitabine, 9 (38%) achieved a partial response and 6 (25%) achieved stable disease (63% disease control rate). Given a cellulitis event and mild activated partial thromboplastin time increases at 6 mg/kg, the 5 mg/kg dose was considered the MTD and selected for further assessment in phase II. CONCLUSION: Acceptable safety and encouraging signals of activity in patients with metastatic pancreatic cancer receiving necuparanib, nab-paclitaxel, and gemcitabine were demonstrated.
Assuntos
Albuminas/administração & dosagem , Desoxicitidina/análogos & derivados , Heparina , Paclitaxel/administração & dosagem , Neoplasias Pancreáticas/tratamento farmacológico , Adulto , Idoso , Albuminas/efeitos adversos , Albuminas/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica , Celulite (Flegmão)/induzido quimicamente , Celulite (Flegmão)/patologia , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Desoxicitidina/farmacocinética , Intervalo Livre de Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Metástase Neoplásica , Paclitaxel/efeitos adversos , Paclitaxel/farmacocinética , Neoplasias Pancreáticas/patologia , Resultado do Tratamento , GencitabinaRESUMO
BACKGROUND & AIMS: The occurrence of drug-induced liver injury (DILI) is a major issue in all phases of drug development. To identify novel biomarker candidates associated with DILI, we utilised an affinity proteomics strategy, where antibody suspension bead arrays were applied to profile plasma and serum samples from human DILI cases and controls. METHODS: An initial screening was performed using 4594 randomly selected antibodies, representing 3450 human proteins. Resulting candidate proteins together with proposed DILI biomarker candidates generated a DILI array of 251 proteins for subsequent target analysis and verifications. In total, 1196 samples from 241 individuals across four independent cohorts were profiled: healthy volunteers receiving acetaminophen, patients with human immunodeficiency virus and/or tuberculosis receiving treatment, DILI cases originating from a wide spectrum of drugs, and healthy volunteers receiving heparins. RESULTS: We observed elevated levels of cadherin 5, type 2 (CDH5) and fatty acid-binding protein 1 (FABP1) in DILI cases. In the two longitudinal cohorts, CDH5 was elevated already at baseline. FABP1 was elevated after treatment initiation and seemed to respond more rapidly than alanine aminotransferase (ALT). The elevations were verified in the DILI cases treated with various drugs. In the heparin cohort, CDH5 was stable over time whereas FABP1 was elevated. CONCLUSIONS: These results suggest that CDH5 may have value as a susceptibility marker for DILI. FABP1 was identified as a biomarker candidate with superior characteristics regarding tissue distribution and kinetics compared to ALT but likely with limited predictive value for the development of severe DILI. Further studies are needed to determine the clinical utility of the proposed markers.
Assuntos
Antígenos CD/sangue , Caderinas/sangue , Doença Hepática Induzida por Substâncias e Drogas/sangue , Proteínas de Ligação a Ácido Graxo/sangue , Acetaminofen/administração & dosagem , Adulto , Alanina Transaminase/sangue , Biomarcadores/sangue , Feminino , Infecções por HIV , Heparina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Proteômica , Fatores de Risco , Tuberculose , Adulto JovemRESUMO
BACKGROUND: The Joint Commission on Accreditation of Healthcare Organizations specifically mandates the dual interpretation of musculoskeletal radiographs by a radiologist in addition to the orthopaedist in all hospital-based orthopaedic clinics. Previous studies have questioned the utility of this practice. The purpose of this study was to further investigate the clinical significance of having the radiologist provide a second interpretation in a hospital-based pediatric orthopaedic clinic. METHODS: A retrospective review was performed of all patients who had plain radiographs obtained in the pediatric orthopaedic clinic at an academic children's hospital over a 4-month period. For each radiographic series, the orthopaedist's note and the radiology interpretation were reviewed and a determination was made of whether the radiology read provided new clinically useful information and/or a new diagnosis, whether it recommended further imaging, or if it missed a diagnosis that was reflected in the orthopaedist's note. The hospital charges associated with the radiology read for each study were also quantified. RESULTS: The charts of 1570 consecutive clinic patients who were seen in the pediatric orthopaedic clinic from January to April, 2012 were reviewed. There were 2509 radiographic studies performed, of which 2264 had both a documented orthopaedist's note and radiologist's read. The radiologist's interpretation added new, clinically important information in 1.0% (23/2264) of these studies. In 1.7% (38/2264) of the studies, it was determined that the radiologist missed the diagnosis or clinically important information that could affect treatment. The total amount of the professional fees charged for the radiologists' interpretations was $87,362. On average, the hospital charges for each occurrence in which the radiologist's read provided an additional diagnosis or clinically important information beyond the orthopaedist's note were $3798. CONCLUSIONS: The results of this study suggest that eliminating the requirement to have the radiologist interpret radiographs in the pediatric orthopaedic clinic would have few clinical consequences. LEVEL OF EVIDENCE: Level III-This is a diagnostic retrospective cohort study.
Assuntos
Hospitais Pediátricos/economia , Ortopedia/economia , Radiologia/economia , Criança , Análise Custo-Benefício , Erros de Diagnóstico , Feminino , Hospitais Pediátricos/normas , Humanos , Masculino , Ortopedia/normas , Papel do Médico , Radiografia , Radiologia/normas , Estudos RetrospectivosRESUMO
BACKGROUND: Closed reduction of pediatric fractures is commonly performed by orthopaedic residents using conscious sedation in the emergency department (ED). The purpose of this study was to determine the rate of satisfactory reductions as performed by residents, and to determine the outcomes of these procedures. METHODS: A retrospective review was performed of all fractures that underwent closed reduction under conscious sedation in the ED of a level 1 pediatric trauma center between January 1, 2010 and November 30, 2014. Initial and subsequent radiographs were reviewed and a determination was made as to whether the initial reduction was satisfactory, based on predetermined criteria for angulation and displacement. If a second reduction attempt in the operating room was necessary, this was noted. Chart notes were reviewed until a documented endpoint was reached, such as uneventful healing, malunion, nonunion, or growth arrest. RESULTS: A total of 838 subjects were identified. The upper extremity was involved in 85% of the fractures. Of the initial 838 fracture reductions performed, 39 (4.7%) were unsatisfactory. Residents on their first pediatric orthopaedic rotation had a higher unsatisfactory reduction rate compared with more experienced residents (7.0% vs. 3.4%, P=0.01). A second reduction was performed for 94 of 749 (12.6%) fractures. Of these, 35 (37.2%) required an open procedure to accomplish a satisfactory reduction. Fractures with initially satisfactory reductions were significantly less likely to require a second reduction attempt than those with initially unsatisfactory reductions (9.2% vs. 80.0%, P<0.01). The likelihood of a satisfactory reduction was significantly higher in the upper extremity than in the lower extremity. Overall, the vast majority (99.2%) of fractures had a satisfactory final outcome. CONCLUSIONS: Most attempts at closed reduction of pediatric fractures in the ED by orthopaedic residents are successful, and the likelihood of a satisfactory reduction was associated with increased levels of resident experience. Fractures with an initially successful reduction were far less likely to require remanipulation. LEVEL OF EVIDENCE: Level IV-this is a therapeutic case series.
Assuntos
Redução Fechada/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Fixação de Fratura/estatística & dados numéricos , Fraturas Ósseas/cirurgia , Internato e Residência , Reoperação/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Redução Fechada/métodos , Sedação Consciente , Feminino , Fraturas Ósseas/diagnóstico por imagem , Humanos , Masculino , Ortopedia/educação , Radiografia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Performance on the Orthopaedic In-training Examination (OITE) has been correlated with performance on the written portion of the American Board of Orthopaedic Surgery examination. Herein we sought to discover whether adding a regular pediatric didactic lecture improved residents' performance on the OITE's pediatric domain. METHODS: In 2012, a didactic lecture series was started in the University of Pittsburgh Medical Center (UPMC) Hamot Orthopaedic Residency Program (Hamot). This includes all topics in pediatric orthopaedic surgery and has teaching faculty present, and occurs weekly with all residents attending. A neighboring program [UMPC Pittsburgh (Pitt)] shares in these conferences, but only during their pediatric rotation. We sought to determine the effectiveness of the conference by comparing the historic scores from each program on the pediatric domain of the OITE examination to scores after the institution of the conference, and by comparing the 2 programs' scores. RESULTS: Both programs demonstrated improvement in OITE scores. In 2008, the mean examination score was 19.6±4.3 (11.0 to 30.0), and the mean percentile was 57.7±12.6 (32.0 to 88.0); in 2014, the mean examination score was 23.5±4.2 (14.0 to 33.0) and the mean percentile was 67.1±12.1 (40.0 to 94.0). OITE scores and percentiles improved with post graduate year (P<0.0001). Compared with the preconference years, Hamot residents answered 3.99 more questions correctly (P<0.0001) and Pitt residents answered 2.93 more questions correctly (P<0.0001). Before the conference, site was not a predictor of OITE score (P=0.06) or percentile (P=0.08); there was no significant difference found between the mean scores per program. However, in the postconference years, site did predict OITE scores. Controlling for year in training, Hamot residents scored higher on the OITE (2.3 points higher, P=0.003) and had higher percentiles (0.07 higher, P=0.004) than Pitt residents during the postconference years. CONCLUSIONS: This study suggests that adding a didactic pediatric lecture improved residents' scores on the OITE and indirectly suggests that more frequent attendance is associated with better scores. LEVEL OF EVIDENCE: Level III-retrospective case-control study.
Assuntos
Educação de Pós-Graduação em Medicina/métodos , Avaliação Educacional , Internato e Residência , Ortopedia/educação , Estudos de Casos e Controles , Humanos , Philadelphia , Estudos Retrospectivos , EnsinoRESUMO
Several single-nucleotide polymorphisms (SNPs) have been associated with papillary and follicular thyroid cancer (PTC and FTC, respectively) risk, but few have replicated. After analyzing 17525 tag SNPs in 1129 candidate genes, we found associations with PTC risk in SERPINA5, FTO, HEMGN (near FOXE1) and other genes. Here, we report results from a replication effort in a large independent PTC/FTC case-control study conducted in Germany. We evaluated the best tagging SNPs from our previous PTC study and additionally included SNPs in or near FOXE1 and NKX2-1 genes, known susceptibility loci for thyroid cancer. We genotyped 422 PTC and 130 FTC cases and 752 controls recruited from three German clinical centers. We used polytomous logistic regression to simultaneously estimate PTC and FTC associations for 79 SNPs based on log-additive models. We assessed effect modification by body mass index (BMI), gender and age for all SNPs, and selected SNP by SNP interactions. We confirmed associations with PTC and SNPs in FOXE1/HEMGN, SERPINA5 (rs2069974), FTO (rs8047395), EVPL (rs2071194), TICAM1 (rs8120) and SCARB1 (rs11057820) genes. We found associations with SNPs in FOXE1, SERPINA5, FTO, TICAM1 and HSPA6 and FTC. We found two significant interactions between FTO (rs8047395) and BMI (P = 0.0321) and between TICAM1 (rs8120) and FOXE1 (rs10984377) (P = 0.0006). Besides the known associations with FOXE1 SNPs, we confirmed additional PTC SNP associations reported previously. We also found several new associations with FTC risk and noteworthy interactions. We conclude that multiple variants and host factors might interact in complex ways to increase risk of PTC and FTC.
Assuntos
Proteínas Adaptadoras de Transporte Vesicular/genética , Adenocarcinoma Folicular/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Carcinoma/genética , Fatores de Transcrição Forkhead/genética , Inibidor da Proteína C/genética , Receptores Depuradores Classe B/genética , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/patologia , Adulto , Idoso , Carcinoma/patologia , Carcinoma Papilar , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/patologiaRESUMO
Acetylcholine (ACh) is a regulator of neural excitability and one of the neurochemical substrates of sleep. Amongst the cellular effects induced by cholinergic modulation are a reduction in spike-frequency adaptation (SFA) and a shift in the phase response curve (PRC). We demonstrate in a biophysical model how changes in neural excitability and network structure interact to create three distinct functional regimes: localized asynchronous, traveling asynchronous, and traveling synchronous. Our results qualitatively match those observed experimentally. Cortical activity during slow wave sleep (SWS) differs from that during REM sleep or waking states. During SWS there are traveling patterns of activity in the cortex; in other states stationary patterns occur. Our model is a network composed of Hodgkin-Huxley type neurons with a M-current regulated by ACh. Regulation of ACh level can account for dynamical changes between functional regimes. Reduction of the magnitude of this current recreates the reduction in SFA the shift from a type 2 to a type 1 PRC observed in the presence of ACh. When SFA is minimal (in waking or REM sleep state, high ACh) patterns of activity are localized and easily pinned by network inhomogeneities. When SFA is present (decreasing ACh), traveling waves of activity naturally arise. A further decrease in ACh leads to a high degree of synchrony within traveling waves. We also show that the level of ACh determines how sensitive network activity is to synaptic heterogeneity. These regimes may have a profound functional significance as stationary patterns may play a role in the proper encoding of external input as memory and traveling waves could lead to synaptic regularization, giving unique insights into the role and significance of ACh in determining patterns of cortical activity and functional differences arising from the patterns.
Assuntos
Acetilcolina/metabolismo , Córtex Cerebral/fisiologia , Colinérgicos/metabolismo , Modelos Neurológicos , Potenciais de Ação/fisiologia , Biologia Computacional , Simulação por Computador , Humanos , Neurônios/metabolismo , Neurônios/fisiologia , Potássio/metabolismo , Sono/fisiologiaRESUMO
BACKGROUND: This study sought to determine the hip pathology of family members of patients with developmental dysplasia of the hip (DDH). The authors evaluated 120 people from 19 families known to have at least 1 member with surgically treated DDH. Each individual's functional outcome scores and pelvic radiographs were assessed for hip symptoms or pathology. METHODS: Using a genetic population database and a pediatric hospital patient population, 19 families with high rates of DDH were identified. All family members (n=120) underwent physical examination, radiographic assessment, and completion of outcome instruments [American Academy of Orthopedics (AAOS) Hip and Knee; Harris Hip Score (HHS); and Western Ontario and McMaster Universities Arthritis Index (WOMAC)]. RESULTS: The 120 subjects ranged from 1 to 84 years, 34 had orthopaedically treated DDH. Of the remaining 86 supposedly normal subjects, 23 (27%) had occult acetabular dysplasia (OAD) as defined by center edge angle (CEA) <20 and/or a Severin score of III or greater. Sixty percent of the 86 individuals were less than 30 years old, 74% of the OAD group were less than 30. Outcome scores of the treated DDH patients (AAOS, HHS, and WOMAC) were worse on the involved side regardless of age. Over age 30 individuals with OAD had statistically significant decreases in their AAOS Hip and Knee and WOMAC scores on the dysplastic side, but their HHS scores were not significantly different. CONCLUSIONS: Twenty-seven percent of first-degree and second-degree relatives of patients with DDH had unsuspected radiographic acetabular dysplasia in our study. Most of the subjects with OAD were younger than 30. After age 30, many of these patients developed symptoms. CLINICAL RELEVANCE: In families with a significant history of DDH, radiographic screening of siblings of patients with DDH to define OAD may be prudent. LEVEL OF EVIDENCE: Level Idiagnostic study.
Assuntos
Acetábulo/anormalidades , Família , Predisposição Genética para Doença , Luxação Congênita de Quadril/epidemiologia , Acetábulo/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Luxação Congênita de Quadril/diagnóstico por imagem , Luxação Congênita de Quadril/genética , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Estados Unidos/epidemiologia , Adulto JovemRESUMO
The growth plate, also known as the physis or epiphyseal plate, is essential for longitudinal growth of bones in the immature skeleton. A variety of insults to the growth plate from trauma to infection to idiopathic causes can lead to physeal bar formation, an interruption in normal growth plate cartilage, where a bony or fibrous bridge develops between the metaphysis and epiphysis. This bridge restricts subsequent bone growth, leading to limb shortening and/or angular deformities. Early recognition of the presence of a physeal bar can help direct appropriate surgical management to restore linear growth of the bone.
Assuntos
Fraturas Ósseas/diagnóstico , Lâmina de Crescimento/anormalidades , Imageamento por Ressonância Magnética/métodos , Fraturas Salter-Harris , Tomografia Computadorizada por Raios X/métodos , Criança , Pré-Escolar , Feminino , Lâmina de Crescimento/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido , MasculinoRESUMO
Neuroglobin (Ngb) promotes neuron survival under hypoxic/ischemic conditions. In vivo and in vitro assays provide evidence for redox-regulated functioning of Ngb. On the basis of X-ray crystal structures and our MD simulations, a mechanism for redox control of human Ngb (hNgb) activity via the influence of the CD loop on the active site is proposed. We provide evidence that the CD loop undergoes a strand-to-helix transition when the external environment becomes sufficiently oxidizing, and that this CD loop conformational transition causes critical restructuring of the active site. We postulate that the strand-to-helix mechanics of the CD loop allows hNgb to utilize the lability of Cys46/Cys55 disulfide bonding and of the Tyr44/His64/heme propionate interaction network for redox-controlled functioning of hNgb.
Assuntos
Globinas/química , Globinas/metabolismo , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Dissulfetos/química , Humanos , Simulação de Dinâmica Molecular , Neuroglobina , Oxirredução , Estrutura Secundária de ProteínaRESUMO
BACKGROUND: Despite advances in glaucoma management, topical eyedrop treatment has been paramount, with prostaglandin analogues (PGAs) being first-line agents. While late presentation is linked with deprivation, there is no recent research examining associations between deprivation and prescribing within primary care. AIM: To explore PGA prescribing in general practice over a 6-year timeline, assessing for associations with deprivation. DESIGN & SETTING: Analysis of NHS Business Services Authority data for general practice prescribing in England from April 2016-March 2022. METHOD: Glaucoma treatments by GP prescriber were extracted, identifying ~9.11-9.58 million prescriptions/annum. Data were linked to indices of multiple deprivation (IMD) quintiles of GP practices. Crude rates per 1,000 population were calculated using population data from NHS Digital. Time-series analyses facilitated comparison in prescribing nationally and in deprived areas. Autoregressive Integrated Moving Average (ARIMA) modelling facilitated measurement of synchrony between time-series using cross correlation. RESULTS: PGAs and fixed combination eyedrops account for approximately two-thirds of glaucoma-related prescribing. Prescriptions per month increased slightly over a 6-year timeline, but rates per 1,000 of population reduced in 2020-21. PGA prescriptions dispensed in deprived areas is lower than all other quintiles. Cross-correlation analysis indicates a lag of ~12 months between average PGA prescribing nationally versus more deprived areas. CONCLUSION: The rate of PGA prescribing in primary care is substantially lower in deprived versus affluent areas, with delayed uptake of PGAs in more deprived areas of ~12 months. Further research is needed to explore reasons for this discrepancy, permitting strategies to be developed to reduce unwarranted variation.
RESUMO
In animal communication, the social context that elicits particular dynamic changes in the signal can provide indirect clues to signal function. Female presence should increase the expression of male signal traits relevant for mate-choice, while male presence should promote the enhancement of traits involved in male-male competition. The electric fish Brachyhypopomus gauderio produces a biphasic electric pulse for electrolocation and communication. Pulse amplitude predicts the signaler's body size while pulse duration predicts circulating androgen levels. Males enhance pulse amplitude and duration when the numbers of males and females increase simultaneously. Here we tested the relative effects of female presence and male presence on male signal enhancement, and whether the size of the male competitor affected this enhancement. We found that male presence drives the enhancement of both pulse amplitude and second phase duration, independently of the size of the male competitor. Female presence induces the enhancement of pulse duration, but not pulse amplitude. These data suggest that males probably attend to information about a competitor's body size coded by pulse amplitude and attend to aggressiveness coded by a competitor's pulse duration, both potential predictors of fight outcome. Females may be primarily concerned about information on reproductive condition coded by pulse duration.
Assuntos
Comunicação Animal , Sinais (Psicologia) , Peixe Elétrico/fisiologia , Órgão Elétrico/fisiologia , Plasticidade Neuronal , Comportamento Social , Androgênios/metabolismo , Animais , Comportamento Competitivo , Peixe Elétrico/metabolismo , Órgão Elétrico/efeitos dos fármacos , Órgão Elétrico/metabolismo , Feminino , Antagonistas de Hormônios/farmacologia , Masculino , Preferência de Acasalamento Animal , Melanocortinas/metabolismo , Potenciais da Membrana , Plasticidade Neuronal/efeitos dos fármacos , Receptores de Melanocortina/antagonistas & inibidores , Receptores de Melanocortina/metabolismo , Fatores Sexuais , Detecção de Sinal Psicológico , Fatores de TempoRESUMO
CASE: This is a case of a female patient born with thrombocytopenia-absent radius syndrome, with bilateral upper extremity phocomelia, bilateral hip dislocations, and congenital fusion of the right knee with progressively worsening flexion contracture. At age 3 years and 5 months, the patient was treated with excision of the knee ankylosis and Van Nes rotationplasty. This proved durable at age 20 years (final follow-up) without any need for further surgery and without complication. CONCLUSION: This is the first known report of Van Nes rotationplasty as a durable treatment option in the management of congenital knee ankylosis, which may avoid reoperation and eliminate risk of recurrence.
Assuntos
Anquilose , Artropatias , Humanos , Feminino , Pré-Escolar , Adulto Jovem , Adulto , Articulação do Joelho/cirurgia , Osteotomia , Reoperação , Artropatias/cirurgia , Anquilose/cirurgiaRESUMO
During perceptual decision-making, the firing rates of cortical neurons reflect upcoming choices. Recent work showed that excitatory and inhibitory neurons are equally selective for choice. However, the functional consequences of inhibitory choice selectivity in decision-making circuits are unknown. We developed a circuit model of decision-making which accounts for the specificity of inputs to and outputs from inhibitory neurons. We found that selective inhibition expands the space of circuits supporting decision-making, allowing for weaker or stronger recurrent excitation when connected in a competitive or feedback motif. The specificity of inhibitory outputs sets the trade-off between speed and accuracy of decisions by either stabilizing or destabilizing the saddle-point dynamics underlying decisions in the circuit. Recurrent neural networks trained to make decisions display the same dependence on inhibitory specificity and the strength of recurrent excitation. Our results reveal two concurrent roles for selective inhibition in decision-making circuits: stabilizing strongly connected excitatory populations and maximizing competition between oppositely selective populations.
Assuntos
Redes Neurais de Computação , Neurônios , Neurônios/fisiologia , Retroalimentação , Modelos Neurológicos , Inibição Neural/fisiologiaRESUMO
BACKGROUND AND OBJECTIVE: Palovarotene, a selective retinoic acid receptor γ agonist, is under investigation for the treatment of dry eye disease. This study aimed to determine the ocular and systemic safety, tolerability and pharmacokinetics of palovarotene ophthalmic solution (PVO-OS) in healthy adults. METHODS: This was a randomised, vehicle-controlled phase I study (NCT04762355; retrospectively registered). Participants received either PVO-OS (at 0.025, 0.05 or 0.10 mg/mL) or a vehicle (placebo-to-match PVO-OS) once-daily or twice-daily for seven consecutive days. Safety was assessed by ocular and systemic assessments. Blood samples for pharmacokinetic assessments were collected before and after dose administration. RESULTS: Thirty-six participants were randomised to PVO-OS and 12 to the vehicle. Overall, 89 treatment-emergent ocular adverse events (TEOAEs) were reported by 22 participants (61.1%) receiving PVO-OS and ten TEOAEs were reported by five participants (41.7%) receiving the vehicle. Erythema, irritation and skin dryness of the eyelid were the most common TEOAEs in participants receiving PVO-OS. The incidence of TEOAEs and eyelid-related findings in the PVO-OS groups increased with ascending dose and frequency compared with participants treated with the vehicle. All TEOAEs were mild (96.6%) or moderate (3.4%) and resolved without sequelae. Plasma palovarotene concentrations were generally measurable for up to 3-4 h for 0.025 mg/mL and 0.05 mg/mL and up to 12 h for 0.10 mg/mL dose regimens, independent of the frequency of administration. CONCLUSIONS: PVO-OS was generally well tolerated at doses up to and including 0.10 mg/mL twice daily. Similar pharmacokinetic profiles were observed for the once-daily and twice-daily regimens following multiple ascending doses of PVO-OS.
Assuntos
Soluções Oftálmicas , Adulto , Humanos , Método Duplo-CegoRESUMO
BACKGROUND: We posed 2 questions: what is the long-term result of open reduction surgery in developmental dysplasia of the hip, and is there an age at surgery above which the outcome was too poor to recommend the operation? METHODS: Between 1955 and 1995, 148 patients with 179 dislocated hips had open reduction surgery for developmental dysplasia of the hip (141 anterior and 38 Ludloff medial approaches). We attempted to locate all 148 patients for the follow-up evaluation. RESULTS: Fifty-three patients (36%) with 66 hips (37%) were located and participated in the study. These 66 hips represented 34% of the anterior open reductions and 47% of the Ludloff medial reductions. Twenty-two of the 66 hips had Severin IV or worse outcomes and included 7 with total hip arthroplasties and 2 with hip fusions. Age at surgery was significantly lower for Severin I, II, and III, compared with Severin IV and above (P=0.003, 0.001, 0.003) with outcomes deteriorating substantially after age 3. Approximately half of the hips required further surgery for dysplasia. All hips that sustained osseous necrosis had Severin IV or worse outcomes, and hips that redislocated and required revision surgery only achieved Severin I or II ratings 18% of the time. Nine "normal" hips became dysplastic and 3 had pelvic osteotomies as teenagers. Two other normal hips developed osseous necrosis during treatment of the contralateral hip. CONCLUSIONS: Results deteriorate as the age at surgery increases. Osseous necrosis and redislocation predict a poor functional and radiographic result. The "normal" hip may develop insidious dysplasia and also may be injured during treatment of the involved hip. Above age 3, some patients may not have sufficient acetabular growth to remodel a surgically reduced hip. LEVEL OF EVIDENCE: Level IV--case series.