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1.
Polymers (Basel) ; 15(13)2023 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-37447442

RESUMEN

This study aims to analyze tire wear particulate matter (TWP) from tread rubber with different formulations and to compare the concentration of TWP with different wear devices. The TWP generated during the abrasion of truck and bus radial (TBR) tires were examined, and the effect of using different types of rubber and carbon black (CB) were investigated. When natural rubber (NR) was solely used as the tire tread rubber material, there was a higher concentration of 5-10 µm TWP. However, when the tread formulation consisted of NR mixed with butadiene rubber, the TWP concentration decreased. Changing the type of CB also reduced the amount of TWP in the 2.5 µm size range. The TWP concentration in the specimens increased with increasing speed and vertical load. The TWP generated during the abrasion tests using wear testers and tire simulators exhibited similar trends. These findings suggest that modifying tire tread formulations can effectively control the distribution and amount of TWP generation.

2.
Tech Coloproctol ; 25(4): 413-423, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33594627

RESUMEN

BACKGROUND: The long-term outcomes of minimally invasive lateral pelvic lymph node dissection (LPND) are not completely known. The aim of this study was to compare long-term outcomes between robotic and laparoscopic LPND in low rectal cancer patients with suspected lymph node metastasis in the pelvic sidewall. METHODS: We retrospectively reviewed the records of all rectal cancer patients who had laparoscopic or robotic total mesorectal excision (TME) with LPND between March 2006 and June 2016. Stage IV patients were excluded. The outcomes of patients who had laparoscopic and robotic TME with LPND were compared. RESULTS: Twenty-nine patients had laparoscopic LPND and 70 had robotic LPND. No significant differences in patient characteristics were observed between the two groups. The urinary retention rate was lower in the robotic group than in the laparoscopic group (7.1% vs. 24.1%; p = 0.043). During a median follow-up of 44.3 months, the overall recurrence rates were 48.3% and 31.4% in the laparoscopic and robotic groups, respectively (p = 0.175). The 5-year disease-free survival rates were 50.4% and 67.0% in the laparoscopic and robotic groups, respectively (p = 0.227). The 5-year overall survival rates were 65.0% and 92.2% in the laparoscopic and robotic groups, respectively (p = 0.017). CONCLUSIONS: Robotic TME with LPND is safe and feasible. In particular, it is associated with lower urinary retention. Robotic TME with LPND might yield a similar local recurrence rate and 5-year disease-free survival, but favorable long-term overall survival as compared to the laparoscopic approach. However, considering the retrospective nature and both major variables of TME and LPND involved together, this should be cautiously interpreted.


Asunto(s)
Laparoscopía , Neoplasias del Recto , Procedimientos Quirúrgicos Robotizados , Humanos , Escisión del Ganglio Linfático , Ganglios Linfáticos , Recurrencia Local de Neoplasia , Neoplasias del Recto/cirugía , Estudios Retrospectivos , Resultado del Tratamiento
3.
Clin Microbiol Infect ; 26(11): 1495-1500, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32062049

RESUMEN

OBJECTIVES: To evaluate the effect of timing and appropriateness of antibiotics administration on mortality in patients diagnosed with sepsis according to the Sepsis-3 definition. METHODS: This prospective cohort study was conducted in patients diagnosed with sepsis according to the Sepsis-3 definition at the emergency department of Korea University Ansan Hospital from January 2016 to January 2019. The time to antibiotics was defined as the time in hours from emergency department arrival to the first antibiotic administration. Cox proportional hazards regression analysis was used to estimate the association between time to antibiotics and 7-, 14- and 28-day mortality. RESULTS: Of 482 patients enrolled onto this study, 203 (42.1%) of 482 and 312 (64.7%) of 482 were diagnosed with septic shock and high-grade infection respectively. The median time to receipt of antibiotic therapy was 115 minutes. Antibiotics were administered within 3 and 6 hours in 340 (70.4%) of 482 and 450 (93.2%) of 482 patients respectively. Initial appropriate empirical antibiotics were administered in 375 (77.8%) of 482 patients. The time to and appropriateness of the initial antibiotics were not associated with 7-, 14- and 28-day mortality in multivariate analysis. The Sequential Organ Failure Assessment (SOFA) score (adjusted hazard ratio (aHR) 1.229, 95% confidence interval (CI) 1.093-1.381, p 0.001) and initial lactate levels (aHR 1.128, 95% CI 1.034-1.230, p 0.007), Charlson comorbidity index (aHR 1.115, 95% CI 1.027-1.210, p 0.014), 2-hour lactate level (aHR 1.115, 95% CI 1.027-1.210, p 0.009) and SOFA score (aHR 1.077, 95% CI 1.013-1.144, p 0.018) affected 7-, 14- and 28-day mortality respectively. Subgroup analysis with septic shock, bacteraemia and high-grade infection did not affect mortality rates. CONCLUSIONS: Time to receipt of antibiotics may not affect the prognosis of patients with sepsis if a rapid and well-trained resuscitation is combined with appropriate antibiotic administration within a reasonable time.


Asunto(s)
Antibacterianos/administración & dosificación , Bacteriemia/tratamiento farmacológico , Choque Séptico/tratamiento farmacológico , Anciano , Antibacterianos/uso terapéutico , Bacteriemia/metabolismo , Femenino , Humanos , Ácido Láctico/análisis , Masculino , Persona de Mediana Edad , Mortalidad , Análisis Multivariante , Puntuaciones en la Disfunción de Órganos , Pronóstico , Estudios Prospectivos , Choque Séptico/metabolismo , Choque Séptico/mortalidad , Factores de Tiempo , Tiempo de Tratamiento
4.
Dermatol Surg ; 46(5): 664-670, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31517664

RESUMEN

BACKGROUND: Absorbable wedge-shaped polydioxanone (PDO) sutures are currently available for facial rejuvenation, and they are extremely popular in the aesthetic clinics in Korea. Other than face lifting, threads also can be used for nonsurgical rhinoplasty. The Asian nose is typified by a flat nasal bridge, indistinct nasal dorsum, underprojected and broad nasal tip, and a short columella. In the past, Asian rhinoplasty mainly focused on dorsal augmentation. At present, augmentation of the nasal tip is very popular and is considered an important aspect of achieving a natural and balanced nose. OBJECTIVE: To describe a novel technique with PDO threads in nonsurgical rhinoplasty. In addition, the authors aimed to assess the overall safety and efficacy of nonsurgical rhinoplasty combining both fillers and threads. METHODS: A retrospective analysis was performed on Korean patients who received rhinoplasty with PDO threads and fillers. All participants underwent a single treatment session. The results were assessed objectively by 2 independent dermatologists using serial photography and subjectively based on the patients' satisfaction scores at 6-month follow-up. RESULTS: A total of 31 patients were evaluated, and 93.5% considered the results satisfactory. Consensus ratings at the 6-month follow-up were largely categorized as very much improved (38.7%), much improved (35.5%), and improved (25.8%). An average increase of 6.3° (percentage increase by 7.6) in the nasolabial angle (p < .05) was measured at follow-up. The incidence of the complications was low, and the ones reported were minor. CONCLUSION: Nonsurgical rhinoplasty combining PDO threads and fillers can be safe and effective, maintaining good results at 6 months after the procedure. Threads are especially useful for lifting-up the nasal tip, contributing to a more harmonious and pleasing nasal appearance by modifying the columella-labial angle.


Asunto(s)
Polidioxanona , Suturas , Adulto , Estética , Femenino , Humanos , Masculino , Satisfacción del Paciente , Rejuvenecimiento , República de Corea , Estudios Retrospectivos , Rinoplastia/instrumentación
5.
Bone Joint J ; 101-B(12): 1506-1511, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31786997

RESUMEN

AIMS: The aim of this study was to compare the osseous reactions elicited by all-suture, polyetheretherketone (PEEK), and two different biodegradable anchors used during rotator cuff repair. PATIENTS AND METHODS: Transosseous-equivalent rotator cuff repair was performed in 73 patients. The patients were divided into two groups, in both of which two different medial-row anchors were used. In group 1, anchor A comprised 30% ß-tricalcium phosphate (TCP) + 70% fast-absorbing poly lactic-co-glycolic acid copolymer (85% polylactic acid enantiomers + 15% polyglycolic acid) and anchor B comprised all-sutures. In group 2, anchor C comprised 23% micro ß-TCP + 77% polylactic acid enantiomers and anchor D comprised PEEK polymer. There were 37 patients in group 1 and 36 patients in group 2. The presence and severity of fluid collection around anchors and healing of the rotator cuff were assessed using MRI scans, approximately one year postoperatively. The severity of the collection was graded as 0 (no perianchor fluid signal), 1 (minimal perianchor fluid), 2 (local collection of fluid), 3 (fluid collection around the whole length of the anchor but of a diameter less than twice the anchor diameter), or 4 (fluid collection around the whole length of the anchor and of a diameter greater than twice the anchor diameter). RESULTS: A perianchor fluid signal was seen in three patients (8.1%) with anchor A, four (10.8%) with anchor B, 15 (41.7%) with anchor C, and 15 (41.7%) with anchor D. The severity of the collection around anchor was grade 2:1:0:0 for anchor A, grade 2:2:0:0 for anchor B, grade 12:2:0:1 for anchor C, and grade 11:3:0:1 for anchor D (grade 1:2:3:4, respectively). The prevalence and severity of fluid formation was not significantly different between anchors A and B, and anchors C and D. However, on intergroup analysis, there were significant differences for the prevalence and severity of fluid formation between anchors in group 1 and group 2. The prevalence of failure to heal was not significant in group 1 (seven, 18.9%) or group 2 (nine, 25.0%). There was no relationship between the presence of perianchor fluid and each type of anchor, and the integrity of the rotator cuff repair, in either group. CONCLUSION: Despite the nonabsorbable nature of all-suture and PEEK anchors, all-suture anchors produced less osseous reaction after rotator cuff repair. In deciding which kind of anchor to use, consideration should be given not only to the strength of the initial fixation, but also to the postoperative biological reaction. Cite this article: Bone Joint J 2019;101-B:1506-1511.


Asunto(s)
Materiales Biocompatibles/efectos adversos , Reacción a Cuerpo Extraño/etiología , Cetonas/efectos adversos , Procedimientos Ortopédicos/instrumentación , Polietilenglicoles/efectos adversos , Complicaciones Posoperatorias/etiología , Lesiones del Manguito de los Rotadores/cirugía , Anclas para Sutura/efectos adversos , Adulto , Anciano , Benzofenonas , Femenino , Estudios de Seguimiento , Reacción a Cuerpo Extraño/diagnóstico por imagen , Reacción a Cuerpo Extraño/epidemiología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Polímeros , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/epidemiología , Prevalencia , Estudios Prospectivos , Lesiones del Manguito de los Rotadores/diagnóstico por imagen , Resultado del Tratamiento , Cicatrización de Heridas
6.
Clin Radiol ; 74(3): 207-215, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30638733

RESUMEN

AIM: To investigate the optimal combined 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT) diagnostic criteria for distinguishing between benign and malignant retroperitoneal soft-tissue masses (RPMs). MATERIALS AND METHODS: A total of 74 patients (M:F=34:40; age, 53±13.2 years) who underwent FDG PET/CT for the initial work-up of RPMs were included. The maximum standardised uptake value (SUVmax), tumour size, presence of fat or calcifications and separated hypermetabolic lesions were included as PET/CT diagnostic parameters. Receiver-operating characteristic (ROC) curves were used to compare the diagnostic performance. RESULTS: The final pathological diagnoses included 52 malignant and 22 benign tumours. High SUVmax (>4.8) and large size (>13 cm) favoured malignancy, and yielded a diagnostic accuracy and AUC of 64.9%, 0.820±0.059, and 68.9%, 0.738±0.061, respectively. In a subgroup of RPMs with a fat component, both SUVmax and size were significantly different between benign and malignant RPM, which yielded a diagnostic accuracy and AUC of 91%, 0.977±0.024 (cut-off, 1.9 cm) and 87.9%, 0.865±0.072 (cut-off, 13 cm), respectively. In a subgroup without a fat component, only SUVmax was significantly different with an accuracy of 90.2% and AUC of 0.919±0.043. The optimal diagnostic flow by combining SUVmax and tumour size after dividing patients into two groups according to the presence of fat showed a sensitivity of 90.4%, a specificity of 95.5%, and an accuracy of 91.9%. CONCLUSIONS: The combination of SUVmax and size according to the presence of a fat component may be the optimal PET/CT diagnostic criteria for distinguishing benign and malignant RPMs.


Asunto(s)
Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Retroperitoneales/diagnóstico por imagen , Neoplasias de los Tejidos Blandos/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Persona de Mediana Edad , Radiofármacos , Neoplasias Retroperitoneales/patología , Neoplasias de los Tejidos Blandos/patología
7.
J Surg Oncol ; 118(1): 199-205, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29949668

RESUMEN

BACKGROUND AND OBJECTIVES: The prognostic value of obesity is unestablished for renal cell carcinoma. We assessed the age-dependent prognostic value of body mass index (BMI) in a large multicenter cohort of patients with non-metastatic clear cell renal cell carcinoma (nm-cRCC). METHODS: This study evaluated 2092 patients with nm-cRCC who underwent surgery with curative intent at five Korean institutions between 2001 and 2014. RESULTS: There was no significant difference in BMI between the young (<45 years) and older patients (≥45 years) (P = 0.398). Among older patients, high BMI (≥25 kg/m2 ) was associated with better 5-year rates of recurrence-free survival (RFS) and cancer-specific survival (CSS) (P = 0.003 and 0.004, respectively), and multivariate analysis confirmed that high BMI was independently associated with better RFS and CSS (RFS hazard ratio [HR]: 0.617, P = 0.005; CSS HR: 0.588, P = 0.024). However, among young patients, there were no significant BMI-related differences in the 5-year RFS and CSS rates (P = 0.457 and 0.420, respectively), and high BMI was not independently associated with RFS or CSS (P = 0.822 and 0.749, respectively). CONCLUSIONS: Among patients with nm-cRCC, high BMI was associated with a favorable prognosis among older patients but not among young patients. Therefore, the relationship between obesity and nm-cRCC prognosis might vary according to age.


Asunto(s)
Carcinoma de Células Renales/cirugía , Neoplasias Renales/cirugía , Adulto , Factores de Edad , Índice de Masa Corporal , Carcinoma de Células Renales/mortalidad , Carcinoma de Células Renales/patología , Estudios de Cohortes , Femenino , Humanos , Estimación de Kaplan-Meier , Neoplasias Renales/mortalidad , Neoplasias Renales/patología , Masculino , Persona de Mediana Edad , Obesidad/mortalidad , Obesidad/patología , Pronóstico , República de Corea/epidemiología , Estudios Retrospectivos
8.
Eur J Clin Microbiol Infect Dis ; 36(11): 2179-2186, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28695355

RESUMEN

To provide optimal cut-off values of anti-Middle East respiratory syndrome coronavirus (MERS-CoV) serologic tests, we evaluated performance of ELISA IgG, ELISA IgA, IFA IgM, and IFA IgG using 138 serum samples of 49 MERS-CoV-infected patients and 219 serum samples of 219 rRT-PCR-negative MERS-CoV-exposed healthcare personnel and patients. The performance analysis was conducted for two different purposes: (1) prediction of neutralization activity in MERS-CoV-infected patients, and (2) epidemiologic surveillance of MERS-CoV infections among MERS-CoV-exposed individuals. To evaluate performance according to serum collection time, we used 'days post onset of illness (dpoi)' and 'days post exposure (dpex)' assessing neutralization activity and infection diagnosis, respectively. Performance of serologic tests improved with delayed sampling time, being maximized after a seroconversion period. In predicting neutralization activity, ELISA IgG tests showed optimal performance using sera collected after 21 dpoi at cut-off values of OD ratio 0.4 (sensitivity 100% and specificity 100%), and ELISA IgA showed optimal performance using sera collected after 14 dpoi at cut-off value of OD ratio 0.2 (sensitivity 85.2% and specificity 100%). In diagnosis of MERS-CoV infection, ELISA IgG exhibited optimal performance using sera collected after 28 dpex, at a cut-off value of OD ratio 0.2 (sensitivity 97.3% and specificity 92.9%). These new breakpoints are markedly lower than previously suggested values (ELISA IgG OD ratio 1.1, sensitivity 34.8% and specificity 100% in the present data set), and the performance data help serologic tests to be practically used in the field of MERS management.


Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por Coronavirus/diagnóstico , Ensayo de Inmunoadsorción Enzimática/métodos , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Pruebas Serológicas/métodos , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Sensibilidad y Especificidad
9.
Transplant Proc ; 49(5): 1012-1017, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28583517

RESUMEN

OBJECTIVE: Bone morphogenetic proteins (BMP) belong to the transforming growth factor beta superfamily of proteins. This study was performed to evaluate the association of BMP gene polymorphisms with acute renal allograft rejection (AR) and graft dysfunction (GD) in Koreans. METHODS: Three hundred thirty-one patients who had kidney transplantation procedures were recruited. Transplantation outcomes were determined in terms of AR and GD criteria. We selected six single nucleotide polymorphisms (SNPs): rs1979855 (5' near gene), rs1049007 (Ser87Ser), rs235767 (intron), rs1005464 (intron), rs235768 (Arg190Ser), and rs3178250 (3; untranslated region). RESULTS: Among the six SNPs tested, the rs235767, rs1005464, and rs3178250 SNPs were significantly associated with AR (P < .05). The rs1049007 and rs235768 SNPs also showed an association with GD (P < .05). CONCLUSIONS: In conclusion, these results suggest that the BMP2 gene polymorphism may be related to the development of AR and GD in kidney transplant recipients.


Asunto(s)
Proteína Morfogenética Ósea 2/genética , Predisposición Genética a la Enfermedad/genética , Rechazo de Injerto/genética , Trasplante de Riñón , Adulto , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple
10.
Mol Psychiatry ; 22(10): 1473-1482, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28138157

RESUMEN

Manic episodes are one of the major diagnostic symptoms in a spectrum of neuropsychiatric disorders that include schizophrenia, obsessive-compulsive disorder and bipolar disorder (BD). Despite a possible association between BD and the gene encoding phospholipase Cγ1 (PLCG1), its etiological basis remains unclear. Here, we report that mice lacking phospholipase Cγ1 (PLCγ1) in the forebrain (Plcg1f/f; CaMKII) exhibit hyperactivity, decreased anxiety-like behavior, reduced depressive-related behavior, hyperhedonia, hyperphagia, impaired learning and memory and exaggerated startle responses. Inhibitory transmission in hippocampal pyramidal neurons and striatal dopamine receptor D1-expressing neurons of Plcg1-deficient mice was significantly reduced. The decrease in inhibitory transmission is likely due to a reduced number of γ-aminobutyric acid (GABA)-ergic boutons, which may result from impaired localization and/or stabilization of postsynaptic CaMKII (Ca2+/calmodulin-dependent protein kinase II) at inhibitory synapses. Moreover, mutant mice display impaired brain-derived neurotrophic factor-tropomyosin receptor kinase B-dependent synaptic plasticity in the hippocampus, which could account for deficits of spatial memory. Lithium and valproate, the drugs presently used to treat mania associated with BD, rescued the hyperactive phenotypes of Plcg1f/f; CaMKII mice. These findings provide evidence that PLCγ1 is critical for synaptic function and plasticity and that the loss of PLCγ1 from the forebrain results in manic-like behavior.


Asunto(s)
Trastorno Bipolar/enzimología , Trastorno Bipolar/genética , Fosfolipasa C gamma/metabolismo , Prosencéfalo/enzimología , Animales , Trastorno Bipolar/parasitología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Hipocampo/enzimología , Hipocampo/metabolismo , Ratones , Plasticidad Neuronal/fisiología , Neuronas/enzimología , Neuronas/metabolismo , Fosfolipasa C gamma/deficiencia , Fosfolipasa C gamma/genética , Prosencéfalo/patología , Células Piramidales/metabolismo , Receptor trkB/metabolismo , Receptores de Dopamina D1 , Sinapsis/enzimología , Sinapsis/patología , Transmisión Sináptica/fisiología , Ácido gamma-Aminobutírico/metabolismo
11.
Front Immunol ; 7: 412, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27790214

RESUMEN

BACKGROUND: A number of studies have demonstrated the role of CX3CR1 in regulating the migration of monocytes into peripheral tissue and their transformation into dendritic cell (DC). No data are yet available on the importance of chemokine pathways in regulating homeostasis of DC in heart transplants. Recently, we showed that recipients of heart allografts from CX3CR1-/- donors show longer survival. To assess the trafficking of dDC, we have developed and tested a novel in vivo imaging tool in CX3CR1GFP/+ DC (B6 background) heart graft into BALB/c recipient model. RESULTS: Majority of GFP+ cells were noted in the middle of cardiac myocyte. However few hours post transplant, they experienced morphological changes including stretching their extensions (3 and 24 h). However, images from 72 h at cardiac graft showed many of GFP+ cells moved to vessel areas. GFP+ cells were detected in near vessel wall. Only one GFP+ cell was observed in three lymph nodes (two mesenteric and one inguinal) (72 h). CONCLUSION: Our data indicate that immediately post transplant dDC undergo morphological changes and traffic out of the organs via systemic circulation. While, we still noted presence of dDC in the transplanted organs, their trafficking to lymphoid tissue remains to be fully explored.

13.
Cell Death Dis ; 7(6): e2261, 2016 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-27277683

RESUMEN

Skeletal muscle has remarkable regeneration capacity and regenerates in response to injury. Muscle regeneration largely relies on muscle stem cells called satellite cells. Satellite cells normally remain quiescent, but in response to injury or exercise they become activated and proliferate, migrate, differentiate, and fuse to form multinucleate myofibers. Interestingly, the inflammatory process following injury and the activation of the myogenic program are highly coordinated, with myeloid cells having a central role in modulating satellite cell activation and regeneration. Here, we show that genetic deletion of microRNA-155 (miR-155) in mice substantially delays muscle regeneration. Surprisingly, miR-155 does not appear to directly regulate the proliferation or differentiation of satellite cells. Instead, miR-155 is highly expressed in myeloid cells, is essential for appropriate activation of myeloid cells, and regulates the balance between pro-inflammatory M1 macrophages and anti-inflammatory M2 macrophages during skeletal muscle regeneration. Mechanistically, we found that miR-155 suppresses SOCS1, a negative regulator of the JAK-STAT signaling pathway, during the initial inflammatory response upon muscle injury. Our findings thus reveal a novel role of miR-155 in regulating initial immune responses during muscle regeneration and provide a novel miRNA target for improving muscle regeneration in degenerative muscle diseases.


Asunto(s)
Inflamación/genética , Inflamación/patología , Macrófagos/metabolismo , MicroARNs/metabolismo , Músculo Esquelético/metabolismo , Regeneración , Animales , Diferenciación Celular/genética , Citocinas/metabolismo , Quinasas Janus/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Biológicos , Músculo Esquelético/lesiones , Músculo Esquelético/patología , Mioblastos/metabolismo , Fenotipo , Factores de Transcripción STAT/metabolismo , Células Satélite del Músculo Esquelético/metabolismo , Proteína 1 Supresora de la Señalización de Citocinas/metabolismo
14.
Opt Lett ; 40(19): 4436-9, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26421550

RESUMEN

We report a novel configuration of a two-stage virtually imaged phased array spectrometer that enables high-throughput sub-GHz spectroscopy at a high finesse (>750). Two etalons with different free spectral range and different dispersion are arranged in an orthogonal direction and spread the spectrum across two dimensions, with a greatly improved rejection ratio of white-light background noise. A proof-of-concept application for Brillouin spectroscopy is demonstrated.


Asunto(s)
Dispositivos Ópticos , Análisis Espectral/instrumentación
15.
Biomed Opt Express ; 6(9): 3313-9, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-26417503

RESUMEN

The mechanical stability of the cornea is critical for maintaining its normal shape and refractive function. Here, we report an observation of the mechanical resonance modes of the cornea excited by sound waves and detected by using phase-sensitive optical coherence tomography. The cornea in bovine eye globes exhibited three resonance modes in a frequency range of 50-400 Hz. The vibration amplitude of the fundamental mode at 80-120 Hz was ~8 µm at a sound pressure level of 100 dB (2 Pa). Vibrography allows the visualization of the radially symmetric profiles of the resonance modes. A dynamic finite-element analysis supports our observation.

16.
Antimicrob Agents Chemother ; 59(1): 356-64, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25367906

RESUMEN

The apicoplast is an essential plastid organelle found in Plasmodium parasites which contains several clinically validated antimalarial-drug targets. A chemical rescue screen identified MMV-08138 from the "Malaria Box" library of growth-inhibitory antimalarial compounds as having specific activity against the apicoplast. MMV-08138 inhibition of blood-stage Plasmodium falciparum growth is stereospecific and potent, with the most active diastereomer demonstrating a 50% effective concentration (EC50) of 110 nM. Whole-genome sequencing of 3 drug-resistant parasite populations from two independent selections revealed E688Q and L244I mutations in P. falciparum IspD, an enzyme in the MEP (methyl-d-erythritol-4-phosphate) isoprenoid precursor biosynthesis pathway in the apicoplast. The active diastereomer of MMV-08138 directly inhibited PfIspD activity in vitro with a 50% inhibitory concentration (IC50) of 7.0 nM. MMV-08138 is the first PfIspD inhibitor to be identified and, together with heterologously expressed PfIspD, provides the foundation for further development of this promising antimalarial drug candidate lead. Furthermore, this report validates the use of the apicoplast chemical rescue screen coupled with target elucidation as a discovery tool to identify specific apicoplast-targeting compounds with new mechanisms of action.


Asunto(s)
Antimaláricos/farmacología , Apicoplastos/efectos de los fármacos , Carbolinas/farmacología , Eritritol/análogos & derivados , Plasmodium falciparum/efectos de los fármacos , Isomerasas Aldosa-Cetosa/antagonistas & inhibidores , Isomerasas Aldosa-Cetosa/genética , Secuencia de Bases , ADN Protozoario/genética , Eritrocitos/parasitología , Humanos , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/parasitología , Pruebas de Sensibilidad Parasitaria , Plasmodium falciparum/genética , Plasmodium falciparum/crecimiento & desarrollo , Análisis de Secuencia de ADN , Terpenos/química , Terpenos/metabolismo
17.
J Vis Exp ; (106): e53468, 2015 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-26779654

RESUMEN

The goal of this protocol is to build a parallel high-extinction and high-resolution optical Brillouin spectrometer. Brillouin spectroscopy is a non-contact measurement method that can be used to obtain direct readouts of viscoelastic material properties. It has been a useful tool in material characterization, structural monitoring and environmental sensing. In the past, Brillouin spectroscopy has usually employed scanning Fabry-Perot etalons to perform spectral analysis. This process requires high illumination power and long acquisition times, making the technique unsuitable for biomedical applications. A recently introduced novel spectrometer overcomes this challenge by employing two VIPAs in a cross-axis configuration. This innovation enables sub-Gigahertz (GHz) resolution spectral analysis with sub-second acquisition time and illumination power within the safety limits of biological tissue. The multiple new applications facilitated by this improvement are currently being explored in biological research and clinical application.


Asunto(s)
Dispersión de Radiación , Análisis Espectral/instrumentación , Diseño de Equipo , Rayos Láser , Luz , Microscopía Confocal/instrumentación , Microscopía Confocal/métodos , Análisis Espectral/métodos
18.
Curr Eye Res ; 40(1): 1-18, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24832392

RESUMEN

Biomechanics is the study of the relationship between forces and function in living organisms and is thought to play a critical role in a significant number of ophthalmic disorders. This is not surprising, as the eye is a pressure vessel that requires a delicate balance of forces to maintain its homeostasis. Over the past few decades, basic science research in ophthalmology mostly confirmed that ocular biomechanics could explain in part the mechanisms involved in almost all major ophthalmic disorders such as optic nerve head neuropathies, angle closure, ametropia, presbyopia, cataract, corneal pathologies, retinal detachment and macular degeneration. Translational biomechanics in ophthalmology, however, is still in its infancy. It is believed that its use could make significant advances in diagnosis and treatment. Several translational biomechanics strategies are already emerging, such as corneal stiffening for the treatment of keratoconus, and more are likely to follow. This review aims to cultivate the idea that biomechanics plays a major role in ophthalmology and that the clinical translation, lead by collaborative teams of clinicians and biomedical engineers, will benefit our patients. Specifically, recent advances and future prospects in corneal, iris, trabecular meshwork, crystalline lens, scleral and lamina cribrosa biomechanics are discussed.


Asunto(s)
Segmento Anterior del Ojo/fisiología , Fenómenos Biomecánicos/fisiología , Glaucoma/fisiopatología , Disco Óptico/fisiología , Animales , Humanos , Presión Intraocular/fisiología , Investigación Biomédica Traslacional
19.
Eur Cell Mater ; 28: 387-403, 2014 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-25422949

RESUMEN

Control of cell-matrix adhesion has become an important issue in the regulation of stem cell function. In this study, a maltose-binding protein (MBP)-linked basic fibroblast growth factor (FGF2)-immobilised polystyrene surface (PS-MBP-FGF2) was applied as an artificial matrix to regulate integrin-mediated signalling. We sought to characterise human mesenchymal-stem cell (hMSC) behaviour in response to two different mechanisms of cell adhesion; (i) FGF2-heparan sulphate proteoglycan (HSPG)-mediated adhesion vs. (ii) fibronectin (FN)-integrin-mediated adhesion. Heparin inhibited hMSC adhesion to PS-MBP-FGF2 but not to FN-coated surface. The phosphorylation of focal adhesion kinase, cytoskeletal re-organisation, and cell proliferation were restricted in hMSCs adhering to PS-MBP-FGF2 compared to FN-coated surface. Expression of MSC markers, such as CD105, CD90 and CD166, decreased in hMSCs expanded on PS-MBP-FGF2 compared to expression in cells expanded on FN-coated surface. hMSCs that were expanded on FN-coated surface differentiated into osteogenic and adipogenic cells more readily than those that were expanded on PS-MBP-FGF2. Furthermore, we characterised the N-linked glycan structures of hMSCs depending on the cell adhesion mechanism using mass spectrometry (MS)-based quantitative techniques. MS analysis revealed that 2,3-sialylated glycans, a potential marker of stem cell function, were more abundant on hMSCs expanded on FN-coated surface than on those expanded on PS-MBP-FGF2. Thus, the differentiation potential of hMSCs is controlled by the type of adhesion substrate that might provide an idea for the design of biomaterials to control stem cell fate. Elucidation of the glycan structure on the cell membrane may help characterise hMSC function.


Asunto(s)
Diferenciación Celular , Matriz Extracelular/metabolismo , Células Madre Mesenquimatosas/citología , Fenotipo , Antígenos CD/genética , Antígenos CD/metabolismo , Adhesión Celular , Proliferación Celular , Fibronectinas/metabolismo , Humanos , Integrinas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/fisiología , Polisacáridos/metabolismo
20.
Opt Express ; 22(13): 15804-19, 2014 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-24977838

RESUMEN

Optical coherence tomography (OCT) is a promising tool for detecting micro channels, metal prints, defects and delaminations embedded in alumina and zirconia ceramic layers at hundreds of micrometers beneath surfaces. The effect of surface roughness and scattering of probing radiation within sample on OCT inspection is analyzed from the experimental and simulated OCT images of the ceramic samples with varying surface roughnesses and operating wavelengths. By Monte Carlo simulations of the OCT images in the mid-IR the optimal operating wavelength is found to be 4 µm for the alumina samples and 2 µm for the zirconia samples for achieving sufficient probing depth of about 1 mm. The effects of rough surfaces and dispersion on the detection of the embedded boundaries are discussed. Two types of image artefacts are found in OCT images due to multiple reflections between neighboring boundaries and inhomogeneity of refractive index.


Asunto(s)
Algoritmos , Artefactos , Cerámica/química , Procesamiento de Imagen Asistido por Computador/métodos , Refractometría/métodos , Dispersión de Radiación , Tomografía de Coherencia Óptica/métodos , Humanos , Luz , Método de Montecarlo
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