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1.
Skeletal Radiol ; 53(3): 489-497, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37650925

RESUMEN

OBJECTIVES: To assess how pars interarticularis fracture characteristics on T1-VIBE and STIR MRI relate to healing and identify anatomical parameters that may impact healing. MATERIALS AND METHODS: A retrospective review of an MRI series of lumbar pars interarticularis injuries in elite athletes over a 3-year period. Fracture configurations, signal intensities and anatomical parameters were recorded by two radiologists. Statistical analysis employed multilevel mixed-effects linear regressions, adjusted for repeated measures and baseline covariates. RESULTS: Forty-seven lumbar pars interarticularis injuries among 31 athletes were assessed. On final scans for each athlete, 15% (7/47) injuries had worsened, 23% (11/47) remained stable, 43% (20/47) partially healed and 19% (9/47) healed completely. Healing times varied, quickest was 49 days for a chronic fracture in a footballer. Bone marrow oedema signal was highest in worsened fractures, followed by improved, and lowest in stable fractures. As healing progressed, T1-VIBE signal at the fracture line decreased. Bone marrow oedema and fracture line signal peaked at 90-120 days before decreasing until 210-240 days. Fractures with smaller dimensions, more vertical orientation and a longer superior articular facet beneath were significantly associated with better healing (p < 0.05). CONCLUSION: Most diagnosed athletic pars interarticularis injuries improve. Normalising T1-VIBE signal at the fracture line is a novel measurable indicator of bony healing. Contrastingly, bone marrow oedema signal is higher in active fractures irrespective of healing or deterioration. Injuries initially perceived as worsening may be exhibiting the normal osteoclastic phase of healing. Better outcomes favour smaller, vertical fractures with a longer superior articular facet beneath.


Asunto(s)
Traumatismos en Atletas , Fracturas Óseas , Espondilólisis , Humanos , Pronóstico , Imagen por Resonancia Magnética/métodos , Traumatismos en Atletas/diagnóstico por imagen , Traumatismos en Atletas/complicaciones , Atletas , Edema/complicaciones , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/lesiones
2.
Stereotact Funct Neurosurg ; 101(1): 22-29, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36702109

RESUMEN

INTRODUCTION: Haemangioblastoma is a benign, vascular tumour of the central nervous system. Stereotactic radiosurgery (SRS) is increasingly being used as a treatment for spinal lesions to avoid complex surgery, especially in patients with multi-focal tumours associated with von Hippel-Lindau syndrome (VHL). Here, we present the outcomes of patients treated in our centre using a CyberKnife VSI (Accuray, Inc.). METHODS: Retrospective analysis of all patients treated at our institution was conducted. Assessment of radiological response was based upon RANO criteria. Solid and overall tumour progression-free survival (PFS) was calculated using the Kaplan-Meier method. The development of a symptomatic new or enlarging cyst was included in the definition of progression when determining overall PFS. RESULTS: Fourteen tumours in 10 patients were included. Seven patients were male, and nine had VHL. Nine (64%) tumours had an associated cyst. The median (IQR) age at treatment was 45.5 (43.5-53) years. The median gross tumour volume was 0.355cc. Patients received a mean marginal prescribed dose of 9.6 Gy in a single fraction (median maximum dose: 14.3 Gy), which was constrained by spinal cord tolerance. Mean follow-up was 15.4 months. Radiologically, 11 (78.6%) tumours were stable or regressed and three (21.4%) progressed. Eight patients' symptoms improved or were stable, and two worsened, both of which were secondary to cyst enlargement. The 1-year solid-tumour and overall PFS was 92.3% and 75.7%, respectively. All patients were alive at the most recent follow-up. One patient developed grade 1 back pain following treatment. DISCUSSION/CONCLUSION: SRS appears to be a safe and effective treatment for spinal haemangioblastoma. Prospective trials with longer follow-up are required to establish the optimum management.


Asunto(s)
Quistes , Hemangioblastoma , Radiocirugia , Humanos , Masculino , Persona de Mediana Edad , Femenino , Hemangioblastoma/patología , Hemangioblastoma/cirugía , Radiocirugia/métodos , Estudios Retrospectivos , Estudios Prospectivos , Resultado del Tratamiento , Quistes/cirugía , Estudios de Seguimiento
3.
Knee Surg Sports Traumatol Arthrosc ; 31(6): 2192-2198, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36539639

RESUMEN

PURPOSE: Lateral ligament ankle sprains are common and the anatomy on imaging studies is vital for accurate diagnosis. The lateral fibulotalocalcaneal ligament (LFTCL) complex consists of the inferior fascicle of the anterior talofibular ligament (ATFL) which is connected by arciform fibres with the calcaneofibular ligament (CFL). The superior fascicle of ATFL is an independent structure that should be assessed individually. MRI evaluation of these distinct fascicles and the arciform fibres has not been described. The aim of this study is to identify the anatomical relationship of these components of the LFTCL complex in healthy individuals on MRI. METHODS: Thirty ankles from healthy volunteers were imaged using 3D volumetric MRI. The ATFL fascicles and size were evaluated. Presence of arciform fibres connecting the inferior ATFL fascicle and CFL to form the LFTCL complex and anatomical relationship around the lateral ligament complex were assessed. RESULTS: Both the superior and inferior ATFL fascicles were observed in 26 (86.7%) ankles. The superior ATFL fascicle was significantly larger in all specimens (39% longer and 80.7% wider). For the specimens with a single fascicle, this was similar in size to the superior fascicle observed in the other 26 specimens. These measurements were not affected by age or gender. Arciform fibres of the LFTCL complex were identified in 22 (84.6%) specimens with two ATFL fascicles and three (75%) ankles with a single ATFL fascicle. Connecting fibres from the ATFL to PTFL were observed in 19 (63.3%) ankles while connections between the CFL and PTFL were identified in 21 (70%) ankles. Five ankles had a perforating artery visualized in the intervening space between the superior and inferior ATFL fascicles (a branch of the lateral tarsal artery of the dorsalis pedis artery). CONCLUSION: Two distinct ATFL fascicles may be identified in the majority of ankles on MRI. Isolated injury to the superior fascicle identified on MRI may be useful when diagnosing patients presenting with symptoms of subtle instability without overt ankle laxity on clinical examination. The current study is the first to identify the arciform fibres of the LFTCL complex supporting isolated ATFL repair in the presence of intact LFTCL complex. LEVEL OF EVIDENCE: Level III.


Asunto(s)
Inestabilidad de la Articulación , Ligamentos Laterales del Tobillo , Humanos , Ligamentos Laterales del Tobillo/lesiones , Articulación del Tobillo/diagnóstico por imagen , Articulación del Tobillo/anatomía & histología , Tobillo , Imagen por Resonancia Magnética , Pie , Cadáver
4.
Int J Mol Sci ; 24(8)2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-37108494

RESUMEN

Myocardial ischemia reperfusion injury (IRI) in acute coronary syndromes is a condition in which ischemic/hypoxic injury to cells subtended by the occluded vessel continues despite successful resolution of the thrombotic obstruction. For decades, most efforts to attenuate IRI have focused on interdicting singular molecular targets or pathways, but none have successfully transitioned to clinical use. In this work, we investigate a nanoparticle-based therapeutic strategy for profound but local thrombin inhibition that may simultaneously mitigate both thrombosis and inflammatory signaling pathways to limit myocardial IRI. Perfluorocarbon nanoparticles (PFC NP) were covalently coupled with an irreversible thrombin inhibitor, PPACK (Phe[D]-Pro-Arg-Chloromethylketone), and delivered intravenously to animals in a single dose prior to ischemia reperfusion injury. Fluorescent microscopy of tissue sections and 19F magnetic resonance images of whole hearts ex vivo demonstrated abundant delivery of PFC NP to the area at risk. Echocardiography at 24 h after reperfusion demonstrated preserved ventricular structure and improved function. Treatment reduced thrombin deposition, suppressed endothelial activation, inhibited inflammasome signaling pathways, and limited microvascular injury and vascular pruning in infarct border zones. Accordingly, thrombin inhibition with an extraordinarily potent but locally acting agent suggested a critical role for thrombin and a promising therapeutic strategy in cardiac IRI.


Asunto(s)
Infarto del Miocardio , Daño por Reperfusión Miocárdica , Trombosis , Animales , Trombina/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Trombosis/tratamiento farmacológico , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/metabolismo , Inflamación/tratamiento farmacológico
5.
Knee Surg Sports Traumatol Arthrosc ; 30(1): 167-175, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33661325

RESUMEN

PURPOSE: In anterior cruciate ligament (ACL) injuries, concomitant damage to peripheral soft tissues is associated with increased rotatory instability of the knee. The purpose of this study was to investigate the incidence and patterns of medial collateral ligament complex injuries in patients with clinically 'isolated' ACL ruptures. METHODS: Patients who underwent ACL reconstruction for complete 'presumed isolated' ACL rupture between 2015 and 2019 were retrospectively included in this study. Patient's characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the grade and location of injuries to the superficial MCL (sMCL), dMCL and the posterior oblique ligament (POL) recorded. All patients were clinically assessed under anaesthesia with standard ligament laxity tests. RESULTS: Hundred patients with a mean age of 22.3 ± 4.9 years were included. The incidence of concomitant MCL complex injuries was 67%. sMCL injuries occurred in 62%, dMCL in 31% and POL in 11% with various injury patterns. A dMCL injury was significantly associated with MRI grade II sMCL injuries, medial meniscus 'ramp' lesions seen at surgery and bone oedema at the medial femoral condyle (MFC) adjacent to the dMCL attachment site (p < 0.01). Logistic regression analysis identified younger age (OR 1.2, p < 0.05), simultaneous sMCL injury (OR 6.75, p < 0.01) and the presence of bone oedema at the MFC adjacent to the dMCL attachment site (OR 5.54, p < 0.01) as predictive factors for a dMCL injury. CONCLUSION: The incidence of combined ACL and medial ligament complex injuries is high. Lesions of the dMCL were associated with ramp lesions, MFC bone oedema close to the dMCL attachment, and sMCL injury. Missed AMRI is a risk factor for ACL graft failure from overload and, hence, oedema in the MCL (especially dMCL) demands careful assessment for AMRI, even in the knee lacking excess valgus laxity. This study provides information about specific MCL injury patterns including the dMCL in ACL ruptures and will allow surgeons to initiate individualised treatment. LEVEL OF EVIDENCE: III.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Ligamentos Colaterales , Inestabilidad de la Articulación , Ligamento Colateral Medial de la Rodilla , Adolescente , Adulto , Ligamento Cruzado Anterior , Lesiones del Ligamento Cruzado Anterior/epidemiología , Lesiones del Ligamento Cruzado Anterior/cirugía , Humanos , Incidencia , Inestabilidad de la Articulación/epidemiología , Inestabilidad de la Articulación/etiología , Inestabilidad de la Articulación/cirugía , Articulación de la Rodilla , Ligamento Colateral Medial de la Rodilla/cirugía , Rango del Movimiento Articular , Estudios Retrospectivos , Tibia , Adulto Joven
6.
Knee Surg Sports Traumatol Arthrosc ; 30(1): 176-183, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33796903

RESUMEN

PURPOSE: The anterolateral soft tissue envelope of the knee is frequently injured at the time of ACL rupture. This study aims to investigate the MRI injury patterns to the Anterolateral complex and their associations in patients with acute 'isolated ligament' ACL ruptures. METHODS: Professional athletes who underwent ACL reconstruction for complete ACL rupture between 2015 and 2019 were included in this study. Patients' characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the injuries to respective structures of the Anterolateral complex and their associations were recorded. RESULTS: Anterolateral complex injuries were noted in 63% of cases. The majority of injuries were to Kaplan Fibre (39% isolated injury and 19% combined with Anterolateral ligament injury). There was a very low incidence of isolated Anterolateral ligament injuries (2%). Kaplan Fibre injuries are associated with the presence of lateral femoral condyle bone oedema, and injuries to the superficial MCL, deep MCL, and ramp lesions. High grade pivot shift test was not associated with the presence of Kaplan Fibre or Anterolateral ligament injuries. Patients with an intact Anterolateral complex sustained injury to other knee structures (13% to medial ligament complex, 14% to medial meniscus, and 16% to lateral meniscus). CONCLUSION: There is a high incidence of concomitant Anterolateral complex injuries in combination with ACL ruptures, with Kaplan Fibre (and therefore the deep capsulo-osseous layer of the iliotibial band) being the most commonly injured structure. Anterolateral ligament injuries occur much less frequently. These findings reinforce the importance of considering the presence of, and if necessary, treating injuries to structures other than the ACL, as a truly isolated ACL injury is rare.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/diagnóstico por imagen , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/epidemiología , Lesiones del Ligamento Cruzado Anterior/cirugía , Fascia Lata , Humanos , Articulación de la Rodilla/cirugía
7.
Knee Surg Sports Traumatol Arthrosc ; 30(5): 1502-1510, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34341846

RESUMEN

PURPOSE: Medial menisco-capsular separations (ramp lesions) are typically found in association with anterior cruciate ligament (ACL) deficiency. They are frequently missed preoperatively due to low MRI sensitivity. The purpose of this article was to describe demographic and anatomical risk factors for ramp lesions, and to identify concomitant lesions and define their characteristics to improve diagnosis of ramp lesions on MRI. METHODS: Patients who underwent anterior cruciate ligament (ACL) reconstruction between September 2015 and April 2019 were included in this study. The presence/absence of ramp lesions was recorded in preoperative MRIs and at surgery. Patients' characteristics and clinical findings, concomitant injuries on MRI and the posterior tibial slope were evaluated. RESULTS: One hundred patients (80 male, 20 female) with a mean age of 22.3 ± 4.9 years met the inclusion criteria. The incidence of ramp lesions diagnosed at surgery was 16%. Ramp lesions were strongly associated with injuries to the deep MCL (dMCL, p < 0.01), the superficial medial collateral ligament (sMCL, p < 0.01), and a small medial-lateral tibial slope asymmetry (p < 0.05). There was also good correlation between ramp lesions and bone oedema in the posterior medial tibia plateau (MTP, p < 0.05) and medial femoral condyle (MFC, p < 0.05). A dMCL injury, a smaller differential medial-lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. MRI sensitivity was 62.5% and the specificity was 84.5%. CONCLUSION: The presence on MRI of sMCL and/or dMCL lesions, bone oedema in the posterior MTP and MFC, and a smaller differential medial-lateral tibial slope than usual are highly associated with ramp lesions visible on MRI. Additionally, a dMCL injury, a flatter lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. Knowledge of the risk factors and secondary injury signs associated with ramp lesions facilitate the diagnosis of a ramp lesion preoperatively and should raise surgeons' suspicion of this important lesion. LEVEL OF EVIDENCE: Diagnostic study, Level III.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Ligamentos Colaterales , Lesiones de Menisco Tibial , Adolescente , Adulto , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/complicaciones , Lesiones del Ligamento Cruzado Anterior/diagnóstico por imagen , Lesiones del Ligamento Cruzado Anterior/cirugía , Atletas , Femenino , Hematoma , Humanos , Imagen por Resonancia Magnética , Masculino , Meniscos Tibiales/cirugía , Estudios Retrospectivos , Tibia/cirugía , Lesiones de Menisco Tibial/cirugía , Adulto Joven
8.
Diabetologia ; 64(6): 1348-1357, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33650017

RESUMEN

AIMS/HYPOTHESIS: Observational studies indicate that type 2 diabetes mellitus and fasting glucose levels are associated with a greater risk for hip fracture, smaller bone area and higher bone mineral density (BMD). However, these findings may be biased by residual confounding and reverse causation. Mendelian randomisation (MR) utilises genetic variants as instruments for exposures in an attempt to address these biases. Thus, we implemented MR to determine whether fasting glucose levels in individuals without diabetes are causally associated with bone area and BMD at the total hip. METHODS: We selected 35 SNPs strongly associated with fasting glucose (p < 5 × 10-8) in a non-diabetic European-descent population from the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) (n = 133,010). MR was used to assess the associations of genetically predicted fasting glucose concentrations with total hip bone area and BMD in 4966 men and women without diabetes from the Swedish Mammography Cohort, Prospective Investigation of Vasculature in Uppsala Seniors and Uppsala Longitudinal Study of Adult Men. RESULTS: In a meta-analysis of the three cohorts, a genetically predicted 1 mmol/l increment of fasting glucose was associated with a 2% smaller total hip bone area (-0.67 cm2 [95% CI -1.30, -0.03; p = 0.039]), yet was also associated, albeit without reaching statistical significance, with a 4% higher total hip BMD (0.040 g/cm2 [95% CI -0.00, 0.07; p = 0.060]). CONCLUSIONS/INTERPRETATION: Fasting glucose may be a causal risk factor for smaller bone area at the hip, yet possibly for greater BMD. Further MR studies with larger sample sizes are required to corroborate these findings.


Asunto(s)
Glucemia , Densidad Ósea/fisiología , Fémur/diagnóstico por imagen , Articulación de la Cadera/diagnóstico por imagen , Polimorfismo de Nucleótido Simple , Anciano , Ayuno/sangre , Femenino , Humanos , Masculino , Análisis de la Aleatorización Mendeliana , Persona de Mediana Edad , Factores de Riesgo
9.
Skeletal Radiol ; 50(2): 433-436, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32638057

RESUMEN

The peroneus quartus is one of a variety of described accessory peroneal muscles, most commonly an incidental finding on MRI or ultrasound of the ankle. We present the only described case in the literature of a peroneus quartus tendon rupture in a professional rugby player as well as the MRI findings.


Asunto(s)
Fútbol Americano , Articulación del Tobillo , Humanos , Pierna , Imagen por Resonancia Magnética , Músculo Esquelético , Rotura/diagnóstico por imagen , Tendones/diagnóstico por imagen
10.
Knee Surg Sports Traumatol Arthrosc ; 29(8): 2424-2436, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32767053

RESUMEN

PURPOSE: The purpose of the study is to review the MRI findings in a cohort of athletes who sustained acute traumatic avulsions of the adductor longus fibrocartilaginous entheses, and to investigate related injuries namely the pyramidalis-anterior pubic ligament-adductor longus complex (PLAC). Associated muscle and soft tissue injuries were also assessed. METHODS: The MRIs were reviewed for a partial or complete avulsion of the adductor longus fibrocartilage, as well as continuity or separation of the adductor longus from the pyramidalis. The presence of a concurrent partial pectineus tear was noted. Demographic data were analysed. Linear and logistic regression was used to examine associations between injuries. RESULTS: The mean age was 32.5 (SD 10.9). The pyramidalis was absent in 3 of 145 patients. 85 of 145 athletes were professional and 52 competed in the football Premier League. 132 had complete avulsions and 13 partial. The adductor longus was in continuity with pyramidalis in 55 athletes, partially separated in seven and completely in 81 athletes. 48 athletes with a PLAC injury had a partial pectineus avulsion. Six types of PLAC injuries patterns were identified. Associated rectus abdominis injuries were rare and only occurred in five patients (3.5%). CONCLUSION: The proximal adductor longus forms part of the PLAC and is rarely an isolated injury. The term PLAC injury is more appropriate term. MRI imaging should assess all the anatomical components of the PLAC post-injury, allowing recognition of the different patterns of injury. LEVEL OF EVIDENCE: Level III.


Asunto(s)
Traumatismos en Atletas , Adulto , Atletas , Traumatismos en Atletas/diagnóstico por imagen , Ingle/lesiones , Humanos , Ligamentos Articulares , Imagen por Resonancia Magnética , Recto del Abdomen
11.
Am Nat ; 196(4): E110-E118, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32970467

RESUMEN

AbstractOrganisms living at high elevations generally grow and develop more slowly than those at lower elevations. Slow montane ontogeny is thought to be an evolved adaptation to harsh environments that improves juvenile quality via physiological trade-offs. However, slower montane ontogeny may also reflect proximate influences of harsh weather on parental care and offspring development. We experimentally heated and protected nests from rain to ameliorate harsh montane weather conditions for mountain blackeyes (Chlorocharis emiliae), a montane songbird living at approximately 3,200 m asl in Malaysian Borneo. This experiment was designed to test whether cold and wet montane conditions contribute to parental care and postnatal growth and development rates at high elevations. We found that parents increased provisioning and reduced time spent warming offspring, which grew faster and departed the nest earlier compared with offspring from unmanipulated nests. Earlier departure reduces time-dependent predation risk, benefitting parents and offspring. These plastic responses highlight the importance of proximate weather contributions to broad patterns of montane ontogeny and parental care.


Asunto(s)
Altitud , Comportamiento de Nidificación , Passeriformes/crecimiento & desarrollo , Tiempo (Meteorología) , Adaptación Fisiológica , Animales , Borneo , Femenino , Masculino , Conducta Materna , Conducta Paterna
12.
Differentiation ; 105: 45-53, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30711828

RESUMEN

Considerable work has gone into creating cell therapies from induced pluripotent stem cells (iPSCs) since their discovery just over a decade ago. However, comparatively little research has been done concerning the safety of iPSCs and their progeny and specifically the mechanisms governing teratogenicity. The aim of this study was to ascertain at what developmental phase iPSCs undergoing differentiation to an alveolar-like phenotype lose their capacity to form a teratoma and uncover potential mechanisms responsible. iPSCs were differentiated using a previously published directed differentiation protocol mirroring alveolar embryogenesis. At each developmental phase cell phenotype was assessed and cells mixed with Matrigel and injected subcutaneously above the hind limbs of NSG mice to determine teratogenicity. A genetic screen of 42 genes commonly associated with teratoma formation was conducted on all the cells and any resulting teratoma. It was found that neither NKX2-1 lung progenitors nor terminally differentiated alveolar-like cells formed teratomas. As expected the expression of pluripotency markers was diminished over differentiation. However, the expression of two proteoglycans, decorin and lumican, was increased more than 3000x during differentiation. Both decorin and lumican are putative tumor suppressors with additional functions in angiogenesis, fibrosis, inflammation and autophagy. We hypothesize that the increasing expression of these proteoglycans by iPSCs as they differentiate may act to inhibit host endothelial cell recruitment when implanted resulting in the inhibition of any teratoma formation by any remaining undifferentiated iPSCs.


Asunto(s)
Células Epiteliales Alveolares/citología , Diferenciación Celular , Células Madre Pluripotentes Inducidas/citología , Fenotipo , Trasplante de Células Madre/efectos adversos , Teratoma/etiología , Animales , Células Cultivadas , Decorina/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Lumican/metabolismo , Masculino , Ratones , Proteoglicanos/metabolismo , Factor Nuclear Tiroideo 1/metabolismo
13.
Proc Natl Acad Sci U S A ; 113(37): 10382-7, 2016 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-27588902

RESUMEN

In many cooperative breeders, the contributions of helpers to cooperative activities change with age, resulting in age-related polyethisms. In contrast, some studies of social mole rats (including naked mole rats, Heterocephalus glaber, and Damaraland mole rats, Fukomys damarensis) suggest that individual differences in cooperative behavior are the result of divergent developmental pathways, leading to discrete and permanent functional categories of helpers that resemble the caste systems found in eusocial insects. Here we show that, in Damaraland mole rats, individual contributions to cooperative behavior increase with age and are higher in fast-growing individuals. Individual contributions to different cooperative tasks are intercorrelated and repeatability of cooperative behavior is similar to that found in other cooperatively breeding vertebrates. Our data provide no evidence that nonreproductive individuals show divergent developmental pathways or specialize in particular tasks. Instead of representing a caste system, variation in the behavior of nonreproductive individuals in Damaraland mole rats closely resembles that found in other cooperatively breeding mammals and appears to be a consequence of age-related polyethism.


Asunto(s)
Envejecimiento/fisiología , Conducta Cooperativa , Ratas Topo/fisiología , Envejecimiento/genética , Animales , Peso Corporal/genética , Peso Corporal/fisiología , Cruzamiento , Femenino , Masculino , Ratas Topo/genética , Ratas , Conducta Sexual Animal/fisiología , Conducta Social
14.
Calcif Tissue Int ; 103(5): 501-511, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29946974

RESUMEN

Men and women with type 2 diabetes mellitus (T2DM) have higher risk of hip fracture, but the mechanisms are not fully understood. We aimed to investigate how T2DM, glucose, and insulin were associated with femoral bone mineral density (BMD), bone mineral area (BMA), and bone turnover markers. We used two cross-sectional cohorts: the Uppsala Longitudinal Study of Adult Men (ULSAM, n = 452, mean age 82 years) and the Swedish Mammography Cohort Clinical (SMCC, n = 4713, mean age 68 years). We identified men and women with normal fasting glucose (NFG), impaired fasting plasma glucose (IFG), and T2DM. BMD and BMA at the total hip and femoral shaft were measured using dual energy X-ray absorptiometry (DXA). Bone turnover markers; CrossLaps and osteocalcin were measured in women. Linear regression models were applied. Men and women showed a progressively higher BMD following the clinical cutoffs of fasting glucose from NFG to IFG to T2DM. In contrast, there was a progressively lower BMA. Men and women with T2DM, compared to those with NFG, had lower BMA at the total hip (- 1.7%; 95% CI - 3.2, - 0.2 and - 1.0%; 95% CI - 1.6, - 0.4) and the femoral shaft (- 2.0%; 95% CI - 3.5, - 0.4 and - 0.6%; 95% CI - 1.2, - 0.01), respectively. T2DM was associated with lower concentrations of CrossLaps (- 8.1%; 95% CI - 12.7, - 3.6) and osteocalcin (- 15.2%; 95% CI - 19.0, - 11.2). These cross-sectional results indicate that those with T2DM have smaller bone area and lower bone turnover, which could increase the risk of hip fracture.


Asunto(s)
Densidad Ósea/fisiología , Remodelación Ósea/fisiología , Diabetes Mellitus Tipo 2/fisiopatología , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Cadera , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Suecia
15.
Differentiation ; 96: 62-69, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28802115

RESUMEN

Protocols to differentiate induced pluripotent stem cells (iPSCs) into specialized cells are continually evolving. iPSCs can be differentiated to alveolar cells with protocols that focus on development, specifically by inducing differentiation into definitive endoderm (DE), anterior foregut endoderm (AFE) and then lung bud progenitor intermediaries. However, current protocols result in a relatively low yield of the desired alveolar cells. The aim of this study was to evaluate whether depleting uncommitted cells after AFE induction would have a beneficial effect on alveolar cell yield. iPSCs were differentiated on Matrigel-coated plates for 25days. At each stage, phenotype was assessed using flow cytometry, immunofluorescence and qRT-PCR. Additionally, samples were dissociated in trypsin following AFE induction to improve the purity of the cells for the subsequent lung differentiation phase. Finally, the efficacy of dissociating the samples was confirmed comparing the expression of markers indicative of pluripotency and apoptosis. The ability to differentiate iPSCs to DE was 96% and to AFE was 97% utilizing our current protocol. After depletion of uncommitted cells and 12 days in culture, the purity of lung bud progenitors was 99%. Finally, the percentage of alveolar types I and II at the end of differentiation was 74% as compared to 31% in control cultures that had not been depleted of uncommitted cells after AFE induction. In conclusion, depletion of uncommitted cells after AFE induction, improves terminal differentiation of alveolar cells from 31% to 74%.


Asunto(s)
Células Epiteliales Alveolares/citología , Diferenciación Celular , Técnicas de Reprogramación Celular/métodos , Endodermo/citología , Células Madre Pluripotentes Inducidas/citología , Células Epiteliales Alveolares/metabolismo , Células Cultivadas , Inducción Embrionaria , Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/metabolismo
16.
Knee Surg Sports Traumatol Arthrosc ; 25(12): 3969-3977, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28866812

RESUMEN

PURPOSE: Adductor longus injuries are complex. The conflict between views in the recent literature and various nineteenth-century anatomy books regarding symphyseal and perisymphyseal anatomy can lead to difficulties in MRI interpretation and treatment decisions. The aim of the study is to systematically investigate the pyramidalis muscle and its anatomical connections with adductor longus and rectus abdominis, to elucidate injury patterns occurring with adductor avulsions. METHODS: A layered dissection of the soft tissues of the anterior symphyseal area was performed on seven fresh-frozen male cadavers. The dimensions of the pyramidalis muscle were measured and anatomical connections with adductor longus, rectus abdominis and aponeuroses examined. RESULTS: The pyramidalis is the only abdominal muscle anterior to the pubic bone and was found bilaterally in all specimens. It arises from the pubic crest and anterior pubic ligament and attaches to the linea alba on the medial border. The proximal adductor longus attaches to the pubic crest and anterior pubic ligament. The anterior pubic ligament is also a fascial anchor point connecting the lower anterior abdominal aponeurosis and fascia lata. The rectus abdominis, however, is not attached to the adductor longus; its lateral tendon attaches to the cranial border of the pubis; and its slender internal tendon attaches inferiorly to the symphysis with fascia lata and gracilis. CONCLUSION: The study demonstrates a strong direct connection between the pyramidalis muscle and adductor longus tendon via the anterior pubic ligament, and it introduces the new anatomical concept of the pyramidalis-anterior pubic ligament-adductor longus complex (PLAC). Knowledge of these anatomical relationships should be employed to aid in image interpretation and treatment planning with proximal adductor avulsions. In particular, MRI imaging should be employed for all proximal adductor longus avulsions to assess the integrity of the PLAC.


Asunto(s)
Ingle/lesiones , Ligamentos Articulares/anatomía & histología , Sínfisis Pubiana/anatomía & histología , Recto del Abdomen/anatomía & histología , Anciano , Cadáver , Ingle/cirugía , Humanos , Masculino , Persona de Mediana Edad
17.
Breast Cancer Res ; 18(1): 57, 2016 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-27233359

RESUMEN

BACKGROUND: Observational studies suggest weight loss and energy restriction reduce breast cancer risk. Intermittent energy restriction (IER) reduces weight to the same extent as, or more than equivalent continuous energy restriction (CER) but the effects of IER on normal breast tissue and systemic metabolism as indicators of breast cancer risk are unknown. METHODS: We assessed the effect of IER (two days of 65 % energy restriction per week) for one menstrual cycle on breast tissue gene expression using Affymetrix GeneChips, adipocyte size by morphometry, and systemic metabolism (insulin resistance, lipids, serum and urine metabolites, lymphocyte gene expression) in 23 overweight premenopausal women at high risk of breast cancer. Unsupervised and supervised analyses of matched pre and post IER biopsies in 20 subjects were performed, whilst liquid and gas chromatography mass spectrometry assessed corresponding changes in serum and urine metabolites in all subjects after the two restricted and five unrestricted days of the IER. RESULTS: Women lost 4.8 % (±2.0 %) of body weight and 8.0 % (±5.0 %) of total body fat. Insulin resistance (homeostatic model assessment (HOMA)) reduced by 29.8 % (±17.8 %) on the restricted days and by 11 % (±34 %) on the unrestricted days of the IER. Five hundred and twenty-seven metabolites significantly increased or decreased during the two restricted days of IER. Ninety-one percent of these returned to baseline after 5 days of normal eating. Eleven subjects (55 %) displayed reductions in energy restriction-associated metabolic gene pathways including lipid synthesis, gluconeogenesis and glycogen synthesis. Some of these women also had increases in genes associated with breast epithelial cell differentiation (secretoglobulins, milk proteins and mucins) and decreased collagen synthesis (TNMD, PCOLCE2, TIMP4). There was no appreciable effect of IER on breast gene expression in the other nine subjects. These groups did not differ in the degree of changes in weight, total body fat, fat cell size or serum or urine metabolomic markers. Corresponding gene changes were not seen in peripheral blood lymphocytes. CONCLUSION: The transcriptional response to IER is variable in breast tissue, which was not reflected in the systemic response, which occurred in all subjects. The mechanisms of breast responsiveness/non-responsiveness require further investigation. TRIAL REGISTRATION: ISRCTN77916487 31/07/2012.


Asunto(s)
Metabolismo Energético , Regulación de la Expresión Génica , Glándulas Mamarias Humanas/metabolismo , Adulto , Biomarcadores , Biopsia , Composición Corporal , Peso Corporal , Neoplasias de la Mama/etiología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Restricción Calórica , Análisis por Conglomerados , Femenino , Hormonas/sangre , Humanos , Resistencia a la Insulina , Lípidos/sangre , Linfocitos/inmunología , Linfocitos/metabolismo , Ciclo Menstrual , Metabolómica/métodos , Persona de Mediana Edad , Carácter Cuantitativo Heredable
18.
Am J Med Genet A ; 170A(4): 1007-16, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26789141

RESUMEN

Many folate-related genes have been investigated for possible causal roles in neural tube defects (NTDs) and oral clefts. However, no previous reports have examined the major gene responsible for folate uptake, the proton-coupled folate transporter (SLC46A1). We tested for association between these birth defects and single nucleotide polymorphisms in the SLC46A1 gene. The NTD study population included 549 complete and incomplete case-family triads, and 999 controls from Ireland. The oral clefts study population comprised a sample from Utah (495 complete and incomplete case-family triads and 551 controls) and 221 Filipino multiplex cleft families. There was suggestive evidence of increased NTD case risk with the rs17719944 minor allele (odds ratio (OR): 1.29; 95% confidence intervals (CI): [1.00-1.67]), and decreased maternal risk of an NTD pregnancy with the rs4795436 minor allele (OR: 0.62; [0.39-0.99]). In the Utah sample, the rs739439 minor allele was associated with decreased case risk for cleft lip with cleft palate (genotype relative risk (GRR): 0.56 [0.32-0.98]). Additionally, the rs2239907 minor allele was associated with decreased case risk for cleft lip with cleft palate in several models, and with cleft palate only in a recessive model (OR: 0.41; [0.20-0.85]). These associations did not remain statistically significant after correcting for multiple hypothesis testing. Nominal associations between SLC46A1 polymorphisms and both Irish NTDs and oral clefts in the Utah population suggest some role in the etiology of these birth defects, but further investigation in other populations is needed.


Asunto(s)
Labio Leporino/genética , Defectos del Tubo Neural/genética , Polimorfismo de Nucleótido Simple , Transportador de Folato Acoplado a Protón/genética , Alelos , Estudios de Casos y Controles , Frecuencia de los Genes , Estudios de Asociación Genética , Genotipo , Humanos , Factores de Riesgo
19.
Am Nat ; 185(3): 380-9, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25674692

RESUMEN

Growth and development rates may result from genetic programming of intrinsic processes that yield correlated rates between life stages. These intrinsic rates are thought to affect adult mortality probability and longevity. However, if proximate extrinsic factors (e.g., temperature, food) influence development rates differently between stages and yield low covariance between stages, then development rates may not explain adult mortality probability. We examined these issues based on study of 90 songbird species on four continents to capture the diverse life-history strategies observed across geographic space. The length of the embryonic period explained little variation (ca. 13%) in nestling periods and growth rates among species. This low covariance suggests that the relative importance of intrinsic and extrinsic influences on growth and development rates differs between stages. Consequently, nestling period durations and nestling growth rates were not related to annual adult mortality probability among diverse songbird species within or among sites. The absence of a clear effect of faster growth on adult mortality when examined in an evolutionary framework across species may indicate that species that evolve faster growth also evolve physiological mechanisms for ameliorating costs on adult mortality. Instead, adult mortality rates of species in the wild may be determined more strongly by extrinsic environmental causes.


Asunto(s)
Mortalidad , Pájaros Cantores/embriología , Pájaros Cantores/crecimiento & desarrollo , Animales , Arizona , Evolución Biológica , Embrión no Mamífero/fisiología , Desarrollo Embrionario , Malasia , Comportamiento de Nidificación/fisiología , Conducta Predatoria/fisiología , Análisis de Regresión , Sudáfrica , Venezuela
20.
Cytometry A ; 87(11): 1012-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26441162

RESUMEN

There is growing interest in the development of methods capable of non-invasive characterization of stem cells prior to their use in cell-based therapies. Raman spectroscopy has previously been used to detect biochemical changes commensurate with the osteogenic, cardiogenic, and neurogenic differentiation of stem cells. The aim of this study was to characterize the adipogenic differentiation of live adipose derived stem cells (ASCs) under aseptic conditions. ASCs were cultured in adipogenic or basal culture medium for 14 days in customized culture flasks containing quartz windows. Raman spectra were acquired every 3 days. Principal component analysis (PCA) was used to identify spectral changes in the cultures over time. Adipogenic differentiation was confirmed using quantitative reverse transcription polymerase chain reaction for the marker genes PPARγ and ADIPOQ and Oil red O staining performed. PCA demonstrated that lipid associated spectral features varied throughout ASC differentiation with the earliest detection of the lipid associated peak at 1,438 cm(-1) after 3 days of induction. After 7 days of culture there were clear differences between the spectra acquired from ASCs in adipogenic or basal culture medium. No changes were observed in the spectra acquired from undifferentiated ASCs. Significant up-regulation in the expression of both PPARγ and ADIPOQ genes (P < 0.001) was observed after 14 days of differentiation as was prominent Oil red O staining. However, the Raman sampling process resulted in weaker gene expression compared with ASCs that had not undergone Raman analysis. This study demonstrated that Raman spectroscopy can be used to detect biochemical changes associated with adipogenic differentiation in a non-invasive and aseptic manner and that this can be achieved as early as three days into the differentiation process.


Asunto(s)
Adipocitos/citología , Adipogénesis/fisiología , Tejido Adiposo/citología , Células Madre/citología , Adulto , Células Cultivadas , Humanos , Persona de Mediana Edad , Espectrometría Raman/métodos , Células del Estroma/citología , Regulación hacia Arriba
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