RESUMEN
Therapeutic management of inflammation in infectious keratitis (IK) requires new strategy and targets for selective immunomodulation. Targeting host cell-type specific inflammatory responses might be a viable strategy to curtail unnecessary inflammation and reduce tissue damage without affecting pathogen clearance. This study explores the possibility of pathogen and host cell-type dependent differences in the inflammatory pathways relevant in the pathogenesis of IK. Human corneal epithelial cell line (HCEC) and phorbol 12-myristate-13 acetate (PMA) differentiated THP-1 macrophage line were infected with either Aspergillus flavus conidia or Acanthamoeba castellanii trophozoites and the elicited inflammatory responses were studied in terms of gene expression and secretion of proinflammatory factors interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) and an upstream inflammatory regulator and mediator protein-the Macrophage Migration Inhibitory Factor (MIF). Given the pleotropic mode of MIF function in diverse cell types relevant in many human diseases, we tested if MIF driven responses to infection is different in HCECs and THP-1 macrophages by studying its expression, secretion and involvement in inflammation by siRNA mediated knockdown. We also examined IK patient tear samples for MIF levels. Infection with A. flavus or A. castellanii induced IL-8 and TNF-α responses in HCECs and THP-1 macrophages but to different levels. Our preliminary human data showed that the level of secreted MIF protein was elevated in IK patient tear, however, MIF secretion by the two cell types were strikingly different in-vitro, under both normal and infected conditions. We found that HCECs released MIF constitutively, which was significantly inhibited with infection, whereas THP-1 macrophages were stimulated to release MIF during infection. MIF gene expression remained largely unaffected by infection in both the cell lines. Although MIF in HCECs appeared to be intracellularly captured during infection, MIF knockdown in HCECs associated with a partial reduction of the IL-8 and TNF-α expression produced by either of the pathogens, suggesting a pro-inflammatory role for MIF in HCECs, independent of its canonical cytokine like function. In contrast, MIF knockdown in THP-1 macrophages accompanied a dramatic increase in IL-8 and TNF-α expression during A. castellanii infection, while the responses to A. flavus infection remained unchanged. These data imply a host cell-type and pathogen specific distinction in the MIF- related inflammatory signaling and MIF as a potential selective immunomodulatory target in infectious keratitis.
Asunto(s)
Queratitis , Factores Inhibidores de la Migración de Macrófagos , Humanos , Factores Inhibidores de la Migración de Macrófagos/genética , Factor de Necrosis Tumoral alfa , Interleucina-8/genética , Inflamación , Inmunomodulación , Oxidorreductasas IntramolecularesRESUMEN
Introduction: Phalanx fractures of the lower limb have high rates of union when manage conservatively. Case Report: A 26-year-old male with fracture of great toe proximal phalanx fracture which was initially managed conservatively with buddy strapping, who missed follow-up and presented late to outpatient department at 6 months with persistence of pain and difficulty in weight bearing. Here, we treated the patient with L-facial plate (2.0 system). Conclusion: Fracture non-union of proximal phalanx can be managed surgically with L- facial plates and screw and bone grafting which will provide full weight bearing and walk normally without any pain and with adequate range of movements.
RESUMEN
The development of magnesium alloy includes two key aspects, such as microstructure and texture, which play vital roles in mechanical and forming behaviour. In this study, cross-rolled Mg-5Al-5Sn alloy at various temperatures (350 °C, 400 °C, and 450 °C) with a 60% reduction in thickness was investigated. The effect of cross rolling temperature on the Mg-5Al-5Sn alloy microstructure, texture, tensile properties, and formability was studied. The yield strength increases from 114 MPa to 150 MPa with decreasing rolling temperature, which is attributed to grain refinement phenomena. This finding demonstrates that the AT55 Mg alloy possesses an impact on cross rolling temperature, viz. the formability increases with increases in cross rolling temperature. The alloy processed at 350 °C shows better strength and less formability than that of the alloy processed at 450 °C ( lower strength but good formability at room temperature, with an Erichsen value of 4.3 mm).
RESUMEN
BACKGROUND: The association between prolonged postoperative opioid use on outcomes after hip preservation surgery is not known. PURPOSE: To compare minimum 2-year patient-reported outcomes (PROs) between patients who required ≥1 postoperative opioid refill after undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) versus patients who did not require a refill and to identify preoperative predictors for patients requiring ≥1 postoperative opioid refill. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Data from consecutive patients who underwent arthroscopic surgery for FAIS between January 2012 and January 2017 were analyzed. Multivariate regression analysis was performed to classify patient and radiographic variables as predictive of requiring ≥1 opioid prescription refill after surgery. Patients completed the following PROs preoperatively and at 2-year follow-up: Hip Outcome Score- Activities of Daily Living subscale (HOS-ADL), HOS-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), International Hip Outcome Tool (iHOT-12), and 100-point visual analog scale (VAS) for pain and satisfaction. Scores were compared between patients needing additional prescription opioids and those who did not. RESULTS: A total of 775 patients, of whom 141 (18.2%) required ≥1 opioid prescription refill, were included in the analysis. Patients requiring opioid refills had significantly lower 2-year postoperative PRO scores compared with patients not requiring refills: HOS-ADL (79.9 ± 20.3 vs 88.7 ± 14.9), HOS-SS (64.6 ± 29.5 vs 78.2 ± 23.7), mHHS (74.2 ± 21.1 vs 83.6 ± 15.9), iHOT-12 (63.6 ± 27.9 vs 74.9 ± 24.8), and VAS satisfaction (73.4 ± 30.3 vs 82.2 ± 24.9), as well as significantly more pain (26.8 ± 23.4 vs 17.9 ± 21.8) (P ≤ .001 for all). Predictors of requiring a postoperative opioid refill included patients with active preoperative opioid use (odds ratio, 3.12 [95% confidence interval, 1.06-9.21]; P = .039) and larger preoperative alpha angles (odds ratio, 1.04 [95% confidence interval, 1.01-1.07]; P = .03). CONCLUSION: Patients requiring ≥1 opioid prescription refill after hip arthroscopy for FAIS had lower preoperative and 2-year PRO scores when compared with patients not requiring refills. Additionally, active opioid use at the time of surgery was found to be predictive of requiring additional opioids for pain management.
RESUMEN
A 5-year-old boy presented with generalized cutaneous erosions, severe scarring, depigmentation and contractures affecting major joints. The lesions had initially affected his ears, nose, feet, and the genital and ocular mucosa, leading to significant depigmentation, scarring, contractures and mutilation. The whole of the trunk and limbs were involved at the time of presentation, with the exception of some islands of spared skin on the proximal thighs, legs, nipples and external genitalia. Electron microscopy revealed a split in the sublamina densa with the absence of anchoring fibrils, suggestive of dystrophic epidermolysis bullosa (EB). Immunofluorescence antigen mapping demonstrated a broad reticulate pattern of staining with collagen IV, VII, and laminin 332 in the floor of the blister, suggestive of Kindler syndrome. Next-generation sequencing revealed a de novo heterozygous missense mutation (a variant of unknown significance) in exon 22 of the phospholipase-C gamma 2 gene (PLCG2), which resulted in a substitution of serine by asparagine at codon 798 (p.Asp798Ser), a result that was validated using Sanger sequencing. The child was diagnosed with PLCG2-associated antibody deficiency and immune dysregulation (PLAID)/autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) syndrome. The cutaneous and corneal erosions, inflammation and scarring of this magnitude, and the eventual result of death have not been described previously for the PLAID/APLAID spectrum previously. In conclusion, this was an unusual acquired autoinflammatory severe EB-like disease that may be associated with de novo PLCG2 mutation.
Asunto(s)
Epidermólisis Ampollosa/genética , Mutación Missense , Fosfolipasa C gamma/genética , Vesícula/genética , Preescolar , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Microscopía Electrónica , Enfermedades Periodontales/genética , Fenotipo , Trastornos por Fotosensibilidad/genética , Piel/patologíaRESUMEN
Erianthus arundinaceus [Retzius] Jeswiet, a wild relative of sugarcane has a high biomass production potential and a reservoir of many genes for superior agronomic traits and tolerance to biotic and abiotic stresses. A comparative physiological, anatomical and root transcriptome analysis were carried out to identify the salt-responsive genes and metabolic pathways associated with salt-tolerant E. arundinaceus genotype IND99-907 and salinity-sensitive sugarcane genotype Co 97010. IND99-907 recorded growth of young leaves, higher proline content, higher relative water content, intact root anatomical structures and lower Na+/K+, Ca2+/K+ and Mg2+/K+ ratio as compared to the sugarcane genotype Co 97010. We have generated four de novo transcriptome assemblies between stressed and control root samples of IND99-907 and Co 97010. A total of 649 and 501 differentially expressed genes (FDR<0.01) were identified from the stressed and control libraries of IND99-907 and Co 97010 respectively. Genes and pathways related to early stress-responsive signal transduction, hormone signalling, cytoskeleton organization, cellular membrane stabilization, plasma membrane-bound calcium and proton transport, sodium extrusion, secondary metabolite biosynthesis, cellular transporters related to plasma membrane-bound trafficking, nucleobase transporter, clathrin-mediated endocytosis were highly enriched in IND99-907. Whereas in Co 97010, genes related to late stress-responsive signal transduction, electron transport system, senescence, protein degradation and programmed cell death, transport-related genes associated with cellular respiration and mitochondrial respiratory chain, vesicular trafficking, nitrate transporter and fewer secondary metabolite biosynthetic genes were highly enriched. A total of 27 pathways, 24 biological processes, three molecular functions and one cellular component were significantly enriched (FDR≤ 0.05) in IND99-907 as compared to 20 pathways, two biological processes without any significant molecular function and cellular components in Co 97010, indicates the unique and distinct expression pattern of genes and metabolic pathways in both genotypes. The genomic resources developed from this study is useful for sugarcane crop improvement through development of genic SSR markers and genetic engineering approaches.
Asunto(s)
Metabolismo Energético/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Saccharum/genética , Estrés Salino , Tolerancia a la Sal/genética , Transcriptoma , Biología Computacional/métodos , Curaduría de Datos , Especificidad de Órganos/genética , Fenotipo , Fenómenos Fisiológicos de las Plantas , Saccharum/metabolismoRESUMEN
PURPOSE: To quantify the prevalence of sacroiliac joint (SIJ) abnormalities in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) by use of various imaging modalities and to compare outcomes based on SIJ abnormalities. METHODS: Plain radiographs, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans of patients who underwent primary hip arthroscopy for FAIS from January 2012 to January 2016 were identified. The exclusion criteria included patients undergoing bilateral or revision surgery, those with a history of dysplasia, and those with less than 2 years' follow-up. On radiographs, the SIJs were graded using modified New York criteria for spondyloarthropathy. CT and MRI scans were reviewed for joint surface erosion, subchondral sclerosis, joint space narrowing, pseudo-widening, bone marrow edema, and ankylosis. Patients with SIJ abnormalities were matched to patients without SIJ abnormalities in a 1:2 ratio by age and body mass index. Outcomes included the Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), visual analog scale (VAS) for pain, and VAS for satisfaction. RESULTS: Of 1,009 consecutive patients, 743 (73.6%) were included; 187 (25.2%) showed SIJ changes. Of these 187 patients, 164 (87.7%) had changes on plain radiographs, 88 (47.1%) had changes on CT, and 125 (66.8%) had changes on MRI. SIJ changes on any imaging modality were weakly correlated with pain to palpation of the SIJ (r = 0.11, P = .004) on physical examination. Pain to palpation of the SIJ on physical examination (odds ratio [OR], 1.12; P = .031) and a history of SIJ pain (OR, 1.93; P = .018) increased the odds of having an SIJ abnormality on any imaging modality. After matching, patients without SIJ abnormalities had a significantly greater HOS-ADL (95.4 vs 90.6, P = .001), HOS-SS (91.1 vs 77.5, P < .001), and mHHS (91.3 vs 84.5, P < .001) and a significantly lower VAS pain score (10.9 vs 25.7, P < .001) than patients with abnormalities at a mean follow-up of 34.1 ± 9.7 months (range, 24-54 months). Patients without SIJ abnormalities had greater odds of achieving the minimal clinically important difference for the HOS-ADL (OR, 2.91; P = .001) and for the HOS-SS (OR, 2.83; P < .001) but not for the mHHS (OR, 1.73; P = .081). CONCLUSIONS: A high prevalence of SIJ abnormalities (25.2%) is seen on imaging in FAIS patients. These patients may show significantly inferior clinical outcomes and persistent postoperative pain after FAIS treatment. The results of this study may allow treating orthopaedic surgeons to better inform patients with SIJ abnormalities that they may not achieve clinically significant outcome improvement after hip arthroscopy. LEVEL OF EVIDENCE: Level III, retrospective comparative study.
Asunto(s)
Pinzamiento Femoroacetabular/cirugía , Articulación Sacroiliaca/diagnóstico por imagen , Actividades Cotidianas , Adolescente , Adulto , Artralgia/diagnóstico por imagen , Artralgia/epidemiología , Artroscopía/métodos , Índice de Masa Corporal , Femenino , Pinzamiento Femoroacetabular/epidemiología , Pinzamiento Femoroacetabular/rehabilitación , Articulación de la Cadera/cirugía , Humanos , Illinois/epidemiología , Artropatías/diagnóstico por imagen , Artropatías/epidemiología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Diferencia Mínima Clínicamente Importante , Oportunidad Relativa , Prevalencia , Pronóstico , Radiografía , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Escala Visual Analógica , Adulto JovenRESUMEN
BACKGROUND: The decreased hip range of motion seen in femoroacetabular impingement syndrome (FAIS) may lead to compensatory increased motion at the symphysis pubis (SP) with resultant increased stress on the joint, which can subsequently lead to osteitis pubis. PURPOSE: To quantify the prevalence of SP abnormalities in patients with FAIS through the use of imaging modalities and to compare outcomes based on the presence of SP abnormalities. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Radiographs and magnetic resonance imaging (MRI) scans of 1009 consecutive patients who underwent primary hip arthroscopy for FAIS from January 2012 to January 2016 were identified. Exclusion criteria were patients undergoing revision or bilateral surgery, patients with dysplasia, and patients with less than 2-year follow-up. On radiographs, SP joints were reviewed for joint surface erosions, subchondral sclerosis and cysts, and ankylosis. MRI scans were reviewed for marrow edema in the subarticular pubic bone, subchondral sclerosis and cysts, joint surface erosions, and ankylosis. Patients with SP abnormalities were matched 1:2 to patients without SP abnormalities by age and body mass index. Outcomes included the Hip Outcome Score-Activities of Daily Living (HOS-ADL), HOS-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (iHOT-12), and visual analog scales (VAS) for pain and satisfaction. RESULTS: 830 patients were included; 23 (2.8%) demonstrated SP abnormalities. Of the 726 (72%) MRI scans reviewed, 15 (1.8%) showed bone marrow edema, subchondral sclerosis, erosions, or ankylosis. After matching, patients without SP abnormalities had significantly greater HOS-ADL (95.7 vs 83.0; P = .008), HOS-SS (91.6 vs 61.9; P = .003), iHOT-12 (89.5 vs 74.6; P = .046), and VAS satisfaction (91.3 vs 58.8; P = .004) scores, in addition to less postoperative pain (6.3 vs 23.5; P < .001). No significant differences were found in the mHHS (92.5 vs 82.2; P = .08). Patients without SP abnormalities had higher odds of achieving the minimal clinically important difference for the HOS-ADL (odds ratio [OR], 4.5; 95% CI, 1.3-14.1; P = .010), the HOS-SS (OR, 7.2; 95% CI, 1.8-18.5; P = .006), and the mHHS (OR, 14.5; 95% CI, 1.8-24.7; P = .013). CONCLUSION: A low prevalence (1.8%-2.6%) of SP joint abnormality is seen on imaging in patients with FAIS. These patients may demonstrate significantly inferior clinical outcomes and persistent postoperative pain after FAIS treatment.
Asunto(s)
Artroscopía/métodos , Pinzamiento Femoroacetabular/cirugía , Articulación de la Cadera/cirugía , Actividades Cotidianas , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diferencia Mínima Clínicamente Importante , Dolor/epidemiología , Satisfacción del Paciente , Prevalencia , Sínfisis Pubiana/anomalías , Rango del Movimiento Articular , Estudios Retrospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
Systemic lupus erythematosus (SLE) is an autoimmune disorder that can affect virtually any organ. Chylous ascites as a presenting manifestation of SLE has been described in a handful of cases in adults. However, to the best of our knowledge this presentation has never been reported in the pediatric age group. Podocytopathy in SLE was initially considered to be a chance association. However, more recently it has been suggested that minimal change disease is not only a chance association; it is part of the lupus nephritis spectrum.
Asunto(s)
Ascitis Quilosa/complicaciones , Riñón/patología , Nefritis Lúpica/complicaciones , Nefritis Lúpica/diagnóstico , Preescolar , Ascitis Quilosa/diagnóstico , Ciclofosfamida/administración & dosificación , Femenino , Humanos , Nefritis Lúpica/tratamiento farmacológico , Nefritis Lúpica/patología , Prednisolona/administración & dosificaciónAsunto(s)
Glucocorticoides/uso terapéutico , Derrame Pleural/diagnóstico por imagen , Escleredema del Adulto/diagnóstico , Serositis/diagnóstico por imagen , Piel/patología , Preescolar , Facies , Femenino , Humanos , Derrame Pleural/complicaciones , Radiografía Torácica , Infecciones del Sistema Respiratorio , Escleredema del Adulto/complicaciones , Escleredema del Adulto/patología , Serositis/complicacionesRESUMEN
PURPOSE: The application of induced pluripotent stem cell-derived retinal pigmented epithelium (iPSC-RPE) in patients with retinal degenerative disease is making headway toward the clinic, with clinical trials already underway. Multiple groups have developed methods for RPE differentiation from pluripotent cells, but previous studies have shown variability in iPSC propensity to differentiate into RPE. METHODS: This study provides a comparison between 2 different methods for RPE differentiation: (1) a commonly used spontaneous continuously adherent culture (SCAC) protocol and (2) a more rapid, directed differentiation using growth factors. Integration-free iPSC lines were differentiated to RPE, which were characterized with respect to global gene expression, expression of RPE markers, and cellular function. RESULTS: We found that all 5 iPSC lines (iPSC-1, iPSC-2, iPSC-3, iPSC-4, and iPSC-12) generated RPE using the directed differentiation protocol; however, 2 of the 5 iPSC lines (iPSC-4 and iPSC-12) did not yield RPE using the SCAC method. Both methods can yield bona fide RPE that expresses signature RPE genes and carry out RPE functions, and are similar, but not identical to fetal RPE. No differences between methods were detected in transcript levels, protein localization, or functional analyses between iPSC-1-RPE, iPSC-2-RPE, and iPSC-3-RPE. Directed iPSC-3-RPE showed enhanced transcript levels of RPE65 compared to directed iPSC-2-RPE and increased BEST1 expression and pigment epithelium-derived factor (PEDF) secretion compared to directed iPSC-1-RPE. In addition, SCAC iPSC-3-RPE secreted more PEDF than SCAC iPSC-1-RPE. CONCLUSIONS: The directed protocol is a more reliable method for differentiating RPE from various pluripotent sources and some iPSC lines are more amenable to RPE differentiation.
Asunto(s)
Células Madre Pluripotentes Inducidas/citología , Epitelio Pigmentado de la Retina/citología , Diferenciación Celular , Línea Celular , HumanosAsunto(s)
Linfohistiocitosis Hemofagocítica/diagnóstico , Paniculitis/diagnóstico , Piel/patología , Azatioprina/uso terapéutico , Niño , Glucocorticoides/uso terapéutico , Humanos , Inmunosupresores/uso terapéutico , Linfohistiocitosis Hemofagocítica/complicaciones , Linfohistiocitosis Hemofagocítica/tratamiento farmacológico , Linfohistiocitosis Hemofagocítica/patología , Masculino , Metilprednisolona/uso terapéutico , Paniculitis/tratamiento farmacológico , Paniculitis/etiología , Paniculitis/patología , Prednisolona/uso terapéuticoRESUMEN
INTRODUCTION: Epidemiologic data on the incidence of venous thromboembolism (VTE) in Indian population vary widely. Most studies show that the incidence of VTE is lower in Asian patients than in Western population. Screening tools to identify high-risk patients should enable us to reduce this complication. METHODS: The incidence of VTE in 101 patients who underwent knee or hip arthroplasty, or surgery for hip fractures, without chemoprophylaxis for deep vein thrombosis (DVT) was documented. Diagnosis of DVT was made with Duplex ultrasonography. We also assessed the usefulness of pre-operative assessment of the hypercoagulable status of the patient in predicting the occurrence of VTE, using the Thrombelastography (TEG) test. RESULTS: The incidence of DVT in the study population was 7%. Six of the 7 patients who developed DVT had surgery for hip fractures, while one had knee replacement. The thrombus was above the knee joint level in 6 of the 7 patients. Pre-operative TEG was positive in only one of the 7 patients, but was positive in 37 of the remaining 94 patients. CONCLUSION: Incidence of DVT in the study population is sufficiently high to recommend some form of prophylaxis to prevent VTE following hip and knee surgery. Pre-operative assessment of the patients' coagulation status with Thrombelastography does not predict the risk of VTE. The use of other lab parameters that could help in selective chemoprophylaxis needs to be explored.
RESUMEN
OBJECTIVE: Templating of the acetabular cup size in Total Hip Replacement (THR) is normally done using conventional radiographs. As these are being replaced by digital radiographs, it has become essential to create a technique of templating using digital films. We describe a technique that involves templating the digital films using the universally available acetate templates for THR without the use of special software. MATERIALS AND METHODS: Preoperative digital radiographs of the pelvis were taken with a 30 mm diameter spherical metal ball strapped over the greater trochanter. Using standard acetate templates provided by the implant company on magnified digital radiographs, the size of the metal ball (X mm) and acetabular cup (Y mm) were determined. The size of the acetabular cup to be implanted was estimated using the formula 30*Y/X. The estimated size was compared with the actual size of the cup used at surgery. RESULTS: Using this technique, it was possible to accurately predict the acetabular cup size in 28/40 (70%) of the hips. When the accuracy to within one size was considered, templating was correct in 90% (36/40). When assessed by two independent observers, there was good intra-observer and inter-observer reliability with intra-class correlation coefficient values greater than 0.8. CONCLUSION: It was possible to accurately and reliably predict the size of the acetabular cup, using acetate templates on digital films, without any digital templates.
RESUMEN
OBJECTIVE: To measure the angular relationships of distal femoral rotational axes in the normal Indian population. MATERIALS AND METHODS: Magnetic Resonance Imaging (MRI) scans of the knee of 40 Indian subjects were used to define the posterior condylar axis, the transepicondylar axis and the Whiteside's line (anteroposterior axis). The posterior condylar angle (PCA) - the angle between the posterior condylar axis and the transepicondylar axis, and the Whiteside-epicondylar angle (W-EP angle) were then calculated. RESULTS: The mean posterior condylar angle in the Indian knee was 4.67° and the mean Whiteside-epicondylar angle was 92.7°. CONCLUSION: There are differences in the distal femoral rotational axes among various races. The mean PCA and the W-EP angle are more externally rotated in the Indian than in the Western, population, but similar to the Chinese. Using fixed values to define the angular relationships between the axes could lead to malrotation of the femoral component. An understanding of the racial differences is essential while designing implants for the Indian population.
RESUMEN
PURPOSE: The purpose of this study was to better understand the role canonical/ß-catenin Wnt signaling plays in the differentiation of human embryonic stem cells (hESCs) into retinal pigmented epithelium (RPE), with the goal of improving methods for derivation. METHODS: Fluorescent reporters were generated to monitor RPE differentiating from hESCs by using a previously described 14-day derivation protocol. Reporters were used to test the effects of the canonical/ß-catenin Wnt pathway agonist CHIR99021 on differentiating RPE. Cells derived from differentiation studies were characterized by lineage-specific transcription factor expression, morphology, pigmentation, and function. The RPE derivation efficiency was determined from percentage positive PMEL17 expression. RESULTS: Fluorescent reporters mimicked expression of endogenous genes during 14-day differentiation to RPE. Analysis of Wnt pathway gene expression showed that the pathway components are expressed in differentiating RPE cells. Addition of CHIR99021 improved RPE derivation based on morphology, expression of RPE-specific lineage markers, and genes involved in melanogenesis. Additionally, expression of the neural retina marker CHX10 was suppressed during differentiation with CHIR99021. Addition of soluble WNT3A, but not WNT5A, had the same result. The CHIR99021-modified protocol yielded cell populations that were 97.77% ± 0.1% positive for the RPE marker PMEL17 at day 14. After cells were expanded to passage 3, they were shown to express RPE markers, carry out phagocytosis of rod outer segments, and secrete pigment epithelium-derived factor apically and vascular endothelial growth factor basally. CONCLUSIONS: Our findings demonstrated the importance of canonical/ß-catenin Wnt signaling in RPE differentiation and showed that manipulating the pathway significantly improves RPE derivation from hESC.
Asunto(s)
Células Madre Embrionarias/citología , Proteínas del Ojo/metabolismo , Regulación del Desarrollo de la Expresión Génica , Degeneración Macular/genética , Factores de Crecimiento Nervioso/metabolismo , ARN/genética , Epitelio Pigmentado de la Retina/metabolismo , Serpinas/metabolismo , beta Catenina/genética , Diferenciación Celular , Células Cultivadas , Citometría de Flujo , Humanos , Inmunohistoquímica , Degeneración Macular/metabolismo , Degeneración Macular/patología , Reacción en Cadena en Tiempo Real de la Polimerasa , Epitelio Pigmentado de la Retina/embriología , Vía de Señalización Wnt , beta Catenina/metabolismoRESUMEN
The work is focused on developing a mathematical model for continuous process of xanthan gum production. The main objective of the study is to simulate the model, observe the behavior of substrate consumption, biomass and product formation with respect to dilution rate and determine the optimum dilution rate for which the reactor is to be designed. Systems with and without recycling of cells are considered and the optimum dilution rate is found. For the kinetic parameters used, the optimum dilution rate for the system with no recycling is 0.205 and 0.35 h(-1) for the system that includes recycling of cells.
Asunto(s)
Modelos Teóricos , Polisacáridos Bacterianos/síntesis química , Saccharum/química , BiomasaRESUMEN
BACKGROUND: Schatzker type V and VI tibial fractures are complex injuries, usually treated with open reduction and internal fixation (ORIF) using dual plates or ring fixators. ORIF has the advantage of not requiring pin tract care, but has a higher infection rate, especially in open fractures. We have combined the advantages of these two methods to treat these difficult fractures. MATERIALS AND METHODS: Ten Schatzker type V and 11 Schatzker type VI fractures were treated between 2006 and 2010. ORIF with dual plates was performed, only if there was marked articular displacement (> 2 mm) in a closed fracture. All other fractures including open fractures and closed fractures with soft tissue compromise or minimal articular displacement were treated with ring fixators. The outcomes were analyzed and documented using the Honkonen and Jarvinen subjective, clinical, functional, and radiological criteria and the Western Ontario and McMaster Universities Arthritis Index (WOMAC). RESULTS: Nine closed fractures with marked articular displacement (> 2 mm) were treated with dual plates. Eight closed fractures with minimal articular displacement (< 2 mm) and poor skin condition and four open fractures were treated with ring fixators. The mean follow-up period was 2 ½ years. The mean postoperative knee flexion was 128°. All patients could walk, jump, and climb steps. 90% could squat, though only 50% could duck walk properly. Radiologically, 85% had a plateau tilt of less than 5°, 92% had an articular step of less than 2 mm, and a residual articular widening of less than 5 mm. There were no major infections. Two patients had minor pin tract infections and two requested that their plates be removed subsequently. CONCLUSION: The protocol used to treat Schatzker type V and VI tibial plateau fractures has had excellent results and we suggest that all open fractures be treated with ring fixators and that ORIF should be done only for closed fractures with marked displacement.