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1.
Int J Mol Sci ; 24(5)2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36902265

RESUMEN

Pathological tissue on the surface of the retina that can be of different etiology and pathogenesis can cause changes in the retina that have a direct consequence on vision. Tissues of different etiology and pathogenesis have different morphological structures and also different macromolecule compositions usually characteristic of specific diseases. In this study, we evaluated and compared biochemical differences among samples of three different types of epiretinal proliferations: idiopathic epiretinal membrane (ERMi), membranes in proliferative vitreoretinopathy (PVRm), and proliferative diabetic retinopathy (PDRm). The membranes were analyzed by using synchrotron radiation-based Fourier transform infrared micro-spectroscopy (SR-FTIR). We used the SR-FTIR micro-spectroscopy setup, where measurements were set to achieve a high resolution that was capable of showing clear biochemical spectra in biological tissue. We were able to identify differences between PVRm, PDRm, and ERMi in protein and lipid structure; collagen content and collagen maturity; differences in proteoglycan presence; protein phosphorylation; and DNA expression. Collagen showed the strongest expression in PDRm, lower expression in ERMi, and very low expression in PVRm. We also demonstrated the presence of silicone oil (SO) or polydimethylsiloxane in the structure of PVRm after SO endotamponade. This finding suggests that SO, in addition to its many benefits as an important tool in vitreoretinal surgery, could be involved in PVRm formation.


Asunto(s)
Retinopatía Diabética , Membrana Epirretinal , Humanos , Sincrotrones , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Análisis de Fourier , Retina/metabolismo , Retinopatía Diabética/metabolismo , Membrana Epirretinal/etiología , Membrana Epirretinal/metabolismo , Membrana Epirretinal/patología
2.
Skin Res Technol ; 28(1): 75-83, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34549464

RESUMEN

BACKGROUND: A synchrotron-based Fourier transform infrared micro-spectrometer (µ-FTIR) allows the spatial determination of lipids across the different layers of ethnic hairs and differentiates between the lipid order arrangement and quantity. MATERIALS AND METHODS: The three ethnic fibers were delipidized, the lipid extracts were characterized, and the delipidized fibers were studied by dynamic vapor sorption experiments (DVS) and FTIR-synchrotron techniques. RESULTS: The average spectra from the different hair regions exhibited the most intense CH2 sym peaks on the medulla, followed by those from the cuticle and cortex for all hairs of different ethnicities. Differences in the lipid fraction of the three hair types have been observed, and they can explain some barrier properties. African virgin hair was demonstrated to have more lipids mainly in the medulla, which implies an important hydrophobicity with low hysteresis between absorption and desorption water vapor processes. In addition, these lipids are highly disordered, mainly in the cuticle, which can be related to its high water vapor diffusion. Asian and Caucasian virgin hairs presented a similar lipid order in all regions, with similar diffusion coefficients. Results indicate that the higher order of the lipid bilayer hinders water permeation kinetics in some way. CONCLUSION: The differences in the presence and organization of the lipids in the different regions of the African hair can account for its differentiation with regards to moisturization and swelling from the other types of fibers.


Asunto(s)
Lípidos , Sincrotrones , Análisis de Fourier , Cabello , Humanos , Espectroscopía Infrarroja por Transformada de Fourier
3.
Int J Mol Sci ; 22(10)2021 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-34065666

RESUMEN

Ultraviolet (UV) irradiation is an important risk factor in cataractogenesis. Lens epithelial cells (LECs), which are a highly metabolically active part of the lens, play an important role in UV-induced cataractogenesis. The purpose of this study was to characterize cell compounds such as nucleic acids, proteins, and lipids in human UV C-irradiated anterior lens capsules (LCs) with LECs, as well as to compare them with the control, non-irradiated LCs of patients without cataract, by using synchrotron radiation-based Fourier transform infrared (SR-FTIR) micro-spectroscopy. In order to understand the effect of the UV C on the LC bio-macromolecules in a context of cataractogenesis, we used the SR-FTIR micro-spectroscopy setup installed on the beamline MIRAS at the Spanish synchrotron light source ALBA, where measurements were set to achieve a single-cell resolution with high spectral stability and high photon flux. UV C irradiation of LCs resulted in a significant effect on protein conformation with protein formation of intramolecular parallel ß-sheet structure, lower phosphate and carboxyl bands in fatty acids and amino acids, and oxidative stress markers with significant increase of lipid peroxidation and diminishment of the asymmetric CH3 band.


Asunto(s)
Cápsula del Cristalino/química , Cápsula del Cristalino/efectos de la radiación , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Rayos Ultravioleta/efectos adversos , Anciano , Carbohidratos/química , Catarata/etiología , Células Epiteliales/química , Células Epiteliales/efectos de la radiación , Ésteres/química , Humanos , Cápsula del Cristalino/diagnóstico por imagen , Peroxidación de Lípido/efectos de la radiación , Masculino , Ácidos Nucleicos/química , Estrés Oxidativo/efectos de la radiación , Conformación Proteica , Proteínas/química , Sincrotrones
4.
Hum Mol Genet ; 26(9): 1716-1731, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28334964

RESUMEN

Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of chronic kidney disease in children. As CAKUT is a genetically heterogeneous disorder and most cases are genetically unexplained, we aimed to identify new CAKUT causing genes. Using whole-exome sequencing and trio-based de novo analysis, we identified a novel heterozygous de novo frameshift variant in the leukemia inhibitory factor receptor (LIFR) gene causing instability of the mRNA in a patient presenting with bilateral CAKUT and requiring kidney transplantation at one year of age. LIFR encodes a transmembrane receptor utilized by IL-6 family cytokines, mainly by the leukemia inhibitory factor (LIF). Mutational analysis of 121 further patients with severe CAKUT yielded two rare heterozygous LIFR missense variants predicted to be pathogenic in three unrelated patients. LIFR mutants showed decreased half-life and cell membrane localization resulting in reduced LIF-stimulated STAT3 phosphorylation. LIFR showed high expression in human fetal kidney and the human ureter, and was also expressed in the developing murine urogenital system. Lifr knockout mice displayed urinary tract malformations including hydronephrosis, hydroureter, ureter ectopia, and, consistently, reduced ureteral lumen and muscular hypertrophy, similar to the phenotypes observed in patients carrying LIFR variants. Additionally, a form of cryptorchidism was detected in all Lifr-/- mice and the patient carrying the LIFR frameshift mutation. Altogether, we demonstrate heterozygous novel or rare LIFR mutations in 3.3% of CAKUT patients, and provide evidence that Lifr deficiency and deactivating LIFR mutations cause highly similar anomalies of the urogenital tract in mice and humans.


Asunto(s)
Receptores OSM-LIF/genética , Receptores OSM-LIF/metabolismo , Anomalías Urogenitales/genética , Adolescente , Adulto , Animales , Niño , Preescolar , Análisis Mutacional de ADN , Exoma , Femenino , Heterocigoto , Humanos , Lactante , Riñón/anomalías , Riñón/patología , Factor Inhibidor de Leucemia/genética , Factor Inhibidor de Leucemia/metabolismo , Subunidad alfa del Receptor del Factor Inhibidor de Leucemia/genética , Subunidad alfa del Receptor del Factor Inhibidor de Leucemia/metabolismo , Masculino , Ratones , Ratones Noqueados , Mutación , Análisis de Secuencia de ADN , Uréter/anomalías , Uréter/patología , Sistema Urinario/patología
5.
Amino Acids ; 51(3): 529-547, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30604095

RESUMEN

We developed and validated gas chromatography-mass spectrometry (GC-MS) methods for the simultaneous measurement of amino acids and their metabolites in 10-µL aliquots of human plasma and urine. De novo synthesized trideutero-methyl esters were used as internal standards. Plasma proteins were precipitated by acidified methanol and removed by centrifugation. Supernatants and native urine were evaporated to dryness. Amino acids were first esterified using 2 M HCl in methanol and then amidated using pentafluoropropionic anhydride for electron-capture negative-ion chemical ionization. Time programmes were used for the gas chromatograph oven and the selected-ion monitoring of specific anions. The GC-MS methods were applied in clinical studies on the HELLP syndrome and pediatric kidney transplantation (KTx) focusing on L-arginine-related pathways. We found lower sarcosine (N-methylglycine) and higher asymmetric dimethylarginine (ADMA) plasma concentrations in HELLP syndrome women (n = 7) compared to healthy pregnant women (n = 5) indicating altered methylation. In plasma of pediatric KTx patients, lower guanidinoacetate and homoarginine concentrations were found in plasma but not in urine samples of patients treated with standard mycophenolate mofetil-based immunosuppression (MMF; n = 22) in comparison to matched patients treated with MMF-free immunosuppression (n = 22). On average, the global arginine bioavailability ratio was by about 40% lower in the MMF group compared to the EVR group (P = 0.004). Mycophenolate, the major pharmacologically active metabolite of MMF, is likely to inhibit the arginine:glycine amidinotransferase (AGAT), and to enhance arginase activity in leukocytes and other types of cell of MMF-treated children.


Asunto(s)
Amidinas/metabolismo , Aminoácidos/sangre , Aminoácidos/orina , Arginasa/metabolismo , Cromatografía de Gases y Espectrometría de Masas/métodos , Síndrome HELLP/metabolismo , Enfermedades Renales/metabolismo , Trasplante de Riñón/métodos , Adolescente , Adulto , Arginina/metabolismo , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Inmunosupresores/farmacología , Enfermedades Renales/tratamiento farmacológico , Enfermedades Renales/cirugía , Metilación , Proyectos Piloto , Embarazo
6.
Analyst ; 144(18): 5511-5520, 2019 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-31393465

RESUMEN

The outcome of radiotherapy can be further improved by combining radiotherapy with nanoparticles. Previous biological studies showed a significant amplification of the biological damage in cells charged with nanoparticles prior to radiotherapy treatments. The rationale has been based on the physical dose enhancement. However, this subject is still a matter of controversy and there are clear indications that biochemical effects may play a key role in the radiosensitization effects of nanoparticles. Within this context, the main goal of our study was to provide new insights into the radiosensitization effects of F98 glioma cells exposed to gadolinium nanoparticles combined with clinical megavoltage beams, and compare them with respect to kilovoltage radiotherapy (commonly used in combination with nanoparticles). For this purpose, we used synchrotron-based Fourier transform infrared microspectroscopy (SR-FTIRM) to provide relevant information on the treatment-induced biochemical changes of the main cell biomolecules. Biochemical differences were evaluated after the treatments to assess cellular damage. Multivariate analysis revealed nanoparticle-dependent changes in megavoltage treated cells. The main spectral variations were related to conformational changes in the protein secondary structures, which might be induced by radiation damage and by changes or rearrangements in the nucleic acid structures due to the initiation of DNA repair mechanisms. We also observed significant changes in the phosphate I and II bands, which concerns DNA damage, while few changes were detected in the lipid region. Spectroscopic data showed that these changes increased as a function of the dose. Finally, PCA analysis did not discriminate clearly between megavoltage and kilovoltage groups treated with nanoparticles, indicating that megavoltage radiosensitization effects might not differ significantly from those in kilovoltage radiotherapy.

7.
Skin Res Technol ; 25(4): 517-525, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30758871

RESUMEN

BACKGROUND: The main objective of this study was to determine the lipid profile of brown and white Caucasian hair fibres and the effects of lipids on the properties of fibres. MATERIALS AND METHODS: To determine the structures of white and brown hair lipid bilayers, cross sections of fibres of both hair types were examined using synchrotron-based µ-FTIR mapping. Dynamic vapour sorption (DVS) analyses were also performed to determine the differences in the barrier function of both fibres. RESULTS: Spatial identification of lipids showed that a great amount of lipids was present in the medulla of fibres of both hair types, but important differences were also observed between cuticles of the different fibres. The cuticle of a white hair fibre showed a significant decrease in its lipid content, but did not show differences in the lateral packing order with respect to the cuticle of a brown hair fibre. The cortex and medulla of the white hair fibre also exhibited a significant decrease in its lipid content but with a higher lateral packing order than brown hair. Using DVS analysis, it was found that the water dynamics of white hair fibres differed from those of brown hair fibres, showing a decrease in their total capacity to absorb water and an increase in the velocity of the exchange of water with the environment. CONCLUSION: The results of both techniques demonstrated a high correlation between the characteristics of the lipids located in the cuticle and the water dynamics of the fibres.


Asunto(s)
Color del Cabello , Cabello , Espectroscopía Infrarroja por Transformada de Fourier , Agua , Humanos , Cabello/química , Cabello/fisiología , Cabello/ultraestructura , Color del Cabello/fisiología , Hidrodinámica , Metabolismo de los Lípidos , Lípidos/sangre , Espectroscopía Infrarroja por Transformada de Fourier/instrumentación , Sincrotrones , Agua/metabolismo
8.
Kidney Blood Press Res ; 43(3): 793-806, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29807363

RESUMEN

BACKGROUND/AIMS: Whether the immunosuppressive regimen is associated with micro- and macro-vascular status in pediatric kidney transplant recipients (KTx) is unknown. METHODS: We performed a cross-sectional, case-control study in 44 pediatric KTx patients on either everolimus (EVR) plus calcineurin inhibitor or standard treatment, i.e. mycophenolate mofetil plus calcineurin inhibitor. Measurement of carotid intima-media thickness (cIMT) via ultrasound, central pulse wave velocity (PWV) by a cuff-based oscillometric technique, and skin microvascular blood flow during local heating via laser-Doppler-fluximetry (LDF) served as marker of subclinical vascular disease. Serum concentrations of angiopoietin-1 and -2, fibroblast-growth factor 23 (FGF23) and soluble klotho were measured. RESULTS: EVR-treated patients exhibited a similar degree of hypertension, increased cIMT, elevated pro-inflammatory angiopoietin-2, and diminished endothelial survival factor angiopoietin-1 compared to healthy children but presented with a twofold more reduced skin micro-vascular function compared to standard treatment (each p< 0.001). By contrast, PWV and soluble klotho levels were normal in both groups. CONCLUSION: Endothelial dysfunction seems more frequent in KTx patients on EVR-based immunosuppressive regimen compared to standard immunosuppression.


Asunto(s)
Inmunosupresores/farmacología , Trasplante de Riñón/efectos adversos , Microcirculación/efectos de los fármacos , Adolescente , Estudios de Casos y Controles , Niño , Preescolar , Estudios Transversales , Endotelio/fisiopatología , Everolimus/farmacología , Everolimus/uso terapéutico , Factor-23 de Crecimiento de Fibroblastos , Humanos , Inmunosupresores/uso terapéutico , Ácido Micofenólico/farmacología , Ácido Micofenólico/uso terapéutico , Enfermedades Vasculares/diagnóstico
9.
Pediatr Nephrol ; 33(4): 727, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29423704

RESUMEN

The article "Rabbit anti-human thymocyte immunoglobulin for the rescue treatment of chronic antibody-mediated rejection after pediatric kidney transplantation", written by Yasemen Cihan, Nele Kanzelmeyer, Jens Drube, Martin Kreuzer, Christian Lerch, Imke Hennies, Kerstin Froede, Murielle Verboom.

10.
Transpl Int ; 30(5): 494-501, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28166398

RESUMEN

Regardless of recipient age at kidney transplantation (KTx), patients are at greatest risk for graft loss in adolescence, partly due to nonadherence to an oral immunosuppressive regimen. Belatacept, a non-nephrotoxic, first-in-class immunosuppressant that inhibits costimulation of T cells requires intravenous application only every 4 weeks, potentially leading to better adherence. However, it is only approved for use in adults. We report here the findings of the first study of belatacept in adolescents, comprising all patients in our department switched to belatacept post-KTx. Six patients (median age 15.5 years) were switched after a median of 7.5 months (range 23 days to 12 years), treatment range 3-28 months (cumulative 83 months): Three patients switched early (<3 months after KTx) had increased estimated glomerular filtration rate (GFR); one patient switched 12 years post-KTx has stable GFR; two patients were switched following rapid decline of and with markedly impaired GFR, changing slope in one patient. One patient had one acute rejection. In addition of two patients who received belatacept for other conditions, the only relevant adverse event was neutropenia (after a cumulative 109 months). Belatacept as primary immunosuppression is an option in Epstein-Barr virus-seropositive nonadherent adolescents if administered sufficiently early before deterioration of graft function.


Asunto(s)
Abatacept/administración & dosificación , Inmunosupresores/administración & dosificación , Trasplante de Riñón , Cumplimiento de la Medicación , Adolescente , Femenino , Humanos , Masculino , Estudios Retrospectivos , Resultado del Tratamiento
11.
Pediatr Nephrol ; 32(1): 91-97, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27350621

RESUMEN

BACKGROUND: Nephropathic cystinosis is a rare lysosomal storage disease which is characterized by the accumulation of free cystine in lysosomes and subsequent intracellular crystal formation of cystine throughout the body. If not treated with cysteamine, a cystine-depleting agent, end-stage renal disease will develop early, followed by multiple organ failure as the disease progresses. The established cysteamine formulation requires a strict dosing regimen at 6-h intervals. An extended release (ER) twice-daily formulation has recently been developed. The aim of our study was to evaluate the implementation and outcomes of this option in routine care. METHODS: All pediatric cystinosis patients' records in Hannover Medical School were screened, and data on cysteamine therapy, tolerability, dosing, estimated glomerular filtration rates (eGFR), white blood cell cystine levels, and proton pump inhibitor (PPI) use were extracted for the period January 2014 to January 2016. RESULTS: The median age of the 12 patients enrolled in the study was 12.5 (range 1-18) years. At the end of the study period ten of these patients received ER-cysteamine. There were no additional side effects. Halitosis/bad breath was often subjectively judged as improved or eliminated, and PPI use could be stopped in one of three patients. The main reasons for switching to the ER formulation were difficult night-time administration and uncontrolled disease. Mean eGFR values remained stable with a median of 67 ml/min/1.73 m2 before and after the transition. White blood cell (WBC) cystine values remained low after the switch (1 nmol/mg protein before and after transition; p = 0.64). CONCLUSIONS: In this single-center cohort, the switch from IR- to ER-cysteamine was safe and effective over the short term and provided advantages in terms of frequency of administration and less halitosis/bad breath. The long-term benefit of this option needs to be evaluated in future studies.


Asunto(s)
Cisteamina/administración & dosificación , Cisteamina/uso terapéutico , Cistinosis/tratamiento farmacológico , Fármacos Renales/administración & dosificación , Fármacos Renales/uso terapéutico , Adolescente , Niño , Preescolar , Estudios de Cohortes , Cisteamina/efectos adversos , Cistina/sangre , Cistinosis/etiología , Preparaciones de Acción Retardada , Composición de Medicamentos , Femenino , Tasa de Filtración Glomerular , Humanos , Lactante , Leucocitos/metabolismo , Masculino , Fármacos Renales/efectos adversos , Estudios Retrospectivos , Resultado del Tratamiento
12.
Pediatr Nephrol ; 32(6): 1005-1011, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28180952

RESUMEN

BACKGROUND: Shiga-toxin-producing Escherichia coli (STEC)-associated hemolytic-uremic syndrome (HUS) is a major cause of acute kidney injury (AKI), especially in children. Its long-term outcome with respect to endothelial damage remains largely elusive. METHODS: This was a cross-sectional study in 26 children who had suffered from STEC-HUS in the past and achieved a complete recovery of renal function (eGFR >90 ml/min/1.73 m2). Skin microcirculation after local heating was assessed by laser Doppler fluximetry, carotid-femoral pulse wave velocity (PWV), carotid intima media thickness (cIMT), 24-h ambulatory blood pressure, and angiopoietin (Ang) 1 and 2 serum levels after a median follow-up period of 6.1 years. The results were compared to those of healthy controls. RESULTS: All patients were normotensive, mean eGFR was 102 (range 91-154) ml/min/1.73 m2, and 13 of the 26 patients showed albuminuria. Endothelial dysfunction was present in 13 patients, and the mean serum Ang2/Ang1 ratio was increased compared to healthy children (each p < 0.05). In contrast, mean values for PWV and cIMT in the patients did not differ from those of the controls. Endothelial dysfunction was significantly associated with younger age at STEC-HUS manifestation, time after HUS, and presence of albuminuria. CONCLUSION: The results of this study highlight the need for long-term follow-up of STEC-HUS patients even after complete recovery of eGFR and lack of hypertension with respect to microvascular damage.


Asunto(s)
Endotelio Vascular/patología , Infecciones por Escherichia coli/patología , Síndrome Hemolítico-Urémico/patología , Microvasos/patología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Lesión Renal Aguda/sangre , Lesión Renal Aguda/etiología , Lesión Renal Aguda/patología , Adolescente , Factores de Edad , Albuminuria/sangre , Angiopoyetina 1/sangre , Angiopoyetina 2/sangre , Monitoreo Ambulatorio de la Presión Arterial , Grosor Intima-Media Carotídeo , Niño , Preescolar , Estudios Transversales , Infecciones por Escherichia coli/sangre , Infecciones por Escherichia coli/microbiología , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Síndrome Hemolítico-Urémico/complicaciones , Síndrome Hemolítico-Urémico/microbiología , Síndrome Hemolítico-Urémico/terapia , Humanos , Hipertensión/diagnóstico , Lactante , Masculino , Análisis de la Onda del Pulso , Diálisis Renal , Piel/irrigación sanguínea , Factores de Tiempo
13.
Pediatr Nephrol ; 32(11): 2133-2142, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28717935

RESUMEN

BACKGROUND: Chronic antibody-mediated rejection (cAMR) is the leading cause of late kidney graft loss, but current therapies are often ineffective. Rabbit anti-human thymocyte immunoglobulin (rATG) may be helpful, but its use is virtually undocumented. METHODS: Data were analyzed retrospectively from nine pediatric kidney transplant patients with cAMR were treated with rATG (1.5 mg/kg × 5 days) at our center after non-response to pulsed prednisolone, intravenous immunoglobulin, rituximab, and increased immunosuppressive intensity (including switching to belatacept in some cases), with or without bortezomib. RESULTS: The median time from diagnosis to cAMR was 179 days. rATG was started 5-741 days after diagnosis. Median estimated glomerular filtration rate (eGFR) increased from 40 mL/min/1.73 m2 when rATG was started to 62 mL/min/1.73 m2 9 months later (p = 0.039). Four patients showed substantially higher eGFR after 9 months and 2 patients showed a small improvement; eGFR continued to decline in 3 patients after starting rATG. No grafts were lost during follow-up. At last follow-up, donor-specific antibodies (DSAs) were no longer detectable in 4 out of 8 patients for whom data were available, median fluorescence intensity had decreased substantially in 1 out of 8 patients; anti-HLA DQ DSAs persisted in 2 out of 8 patients. No adverse events with a suspected relation to rATG, including allergic reactions, leukocytopenia or infections, were observed in any of the patients. CONCLUSIONS: In this small series of patients, rATG appears a promising treatment for unresponsive cAMR. Further evaluation, including earlier introduction of rATG, is warranted.


Asunto(s)
Suero Antilinfocítico/uso terapéutico , Rechazo de Injerto/tratamiento farmacológico , Inmunosupresores/uso terapéutico , Trasplante de Riñón/efectos adversos , Adolescente , Animales , Bortezomib/uso terapéutico , Preescolar , Enfermedad Crónica , Femenino , Tasa de Filtración Glomerular , Rechazo de Injerto/inmunología , Supervivencia de Injerto , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Riñón/inmunología , Riñón/patología , Riñón/cirugía , Masculino , Prednisolona/uso terapéutico , Conejos , Estudios Retrospectivos , Rituximab/uso terapéutico , Resultado del Tratamiento
14.
Hum Genet ; 135(1): 69-87, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26572137

RESUMEN

Congenital anomalies of the kidneys and urinary tract (CAKUT) are genetically highly heterogeneous leaving most cases unclear after mutational analysis of the around 30 causative genes known so far. Assuming that phenotypes frequently showing dominant inheritance, such as CAKUT, can be caused by de novo mutations, de novo analysis of whole-exome sequencing data was done on two patient-parent-trios to identify novel CAKUT genes. In one case, we detected a heterozygous de novo frameshift variant in TBC1D1 encoding a Rab-GTPase-activating protein regulating glucose transporter GLUT4 translocation. Sequence analysis of 100 further CAKUT cases yielded three novel or rare inherited heterozygous TBC1D1 missense variants predicted to be pathogenic. TBC1D1 mutations affected Ser237-phosphorylation or protein stability and thereby act as hypomorphs. Tbc1d1 showed widespread expression in the developing murine urogenital system. A mild CAKUT spectrum phenotype, including anomalies observed in patients carrying TBC1D1 mutations, was found in kidneys of some Tbc1d1 (-/-) mice. Significantly reduced Glut4 levels were detected in kidneys of Tbc1d1 (-/-) mice and the dysplastic kidney of a TBC1D1 mutation carrier versus controls. TBC1D1 and SLC2A4 encoding GLUT4 were highly expressed in human fetal kidney. The patient with the truncating TBC1D1 mutation showed evidence for insulin resistance. These data demonstrate heterozygous deactivating TBC1D1 mutations in CAKUT patients with a similar renal and ureteral phenotype, and provide evidence that TBC1D1 mutations may contribute to CAKUT pathogenesis, possibly via a role in glucose homeostasis.


Asunto(s)
Exoma , Proteínas Activadoras de GTPasa/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Mutación , Anomalías Urogenitales/genética , Reflujo Vesicoureteral/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Animales , Niño , Preescolar , Femenino , Proteínas Activadoras de GTPasa/química , Humanos , Lactante , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Datos de Secuencia Molecular , Linaje , Homología de Secuencia de Aminoácido , Adulto Joven
15.
Pediatr Nephrol ; 30(12): 2199-206, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26227629

RESUMEN

BACKGROUND: Acute kidney injury (AKI) is a major complication in children with hepatic failure which leads to increased morbidity and mortality. The aim of this study was to provide paediatric data on the prevalence of dialysis-dependent AKI (dAKI), the feasibility and efficacy of dialysis methods and outcome. METHODS: We conducted a retrospective analysis of 367 children listed for orthotopic liver transplantation (OLT) in our centre during the past decade. RESULTS: Data on 30 children (15 boys, 15 girls) were compiled for retrospective analysis, and data on dialysis feasibility and efficacy were available for 26 of these. Median age was 3.5 (range 0.4-17.7) years. Median MELD (Model For End-Stage Liver Disease) score was 33. dAKI was caused by hepato-renal syndrome in 16 of the 30 children. Twenty-one patients were treated with continuous veno-venous haemofiltration (CVVH), and nine patients received peritoneal dialysis (PD). Overall mortality was 77%. Mortality within the PD-group was 100 % versus 67% in the CVVH-group (p = 0.039). Urea reduction rate within the first 24 h of treatment was 12.9% in the PD group and 23.5% in the CVVH group (p = 0.019). CONCLUSIONS: Children with end-stage liver disease have a high risk for dAKI associated with high mortality. CVVH is associated with better efficacy and less mortality than PD.


Asunto(s)
Lesión Renal Aguda/etiología , Enfermedad Hepática en Estado Terminal/terapia , Diálisis Renal/efectos adversos , Lesión Renal Aguda/epidemiología , Adolescente , Niño , Preescolar , Enfermedad Hepática en Estado Terminal/mortalidad , Femenino , Humanos , Lactante , Masculino , Prevalencia , Diálisis Renal/métodos , Estudios Retrospectivos , Tasa de Supervivencia
16.
Biomater Adv ; 164: 213982, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39098081

RESUMEN

The efficiency of synthetic bone grafts can be evaluated either in osseous sites, to analyze osteoconduction or ectopically, in intramuscular or subcutaneous sites, to assess osteoinduction. Bone regeneration is usually evaluated in terms of the presence and quantity of newly formed bone, but little information is normally provided on the quality of this bone. Here, we propose a novel approach to evaluate bone quality by the combined use of spectroscopy techniques and nanoindentation. Calcium phosphate scaffolds with different architectures, either foamed or 3D-printed, that were implanted in osseous or intramuscular defects in Beagle dogs for 6 or 12 weeks were analyzed. ATR-FTIR and Raman spectroscopy were performed, and mineral-to-matrix ratio, crystallinity, and mineral and collagen maturity were calculated and mapped for the newly regenerated bone and the mature cortical bone from the same specimen. For all the parameters studied, the newly-formed bone showed lower values than the mature host bone. Hardness and elastic modulus were determined by nanoindentation and, in line with what was observed by spectroscopy, lower values were observed in the regenerated bone than in the cortical bone. While, as expected, all techniques pointed to an increase in the maturity of the newly-formed bone between 6 and 12 weeks, the bone found in the intramuscular samples after 12 weeks presented lower mineralization than the intraosseous counterparts. Moreover, scaffold architecture also played a role in bone maturity, with the foamed scaffolds showing higher mineralization and crystallinity than the 3D-printed scaffolds after 12 weeks.


Asunto(s)
Regeneración Ósea , Andamios del Tejido , Animales , Perros , Regeneración Ósea/fisiología , Andamios del Tejido/química , Espectrometría Raman/métodos , Fosfatos de Calcio/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Huesos/química , Huesos/fisiología , Impresión Tridimensional
17.
J Mater Chem B ; 12(31): 7577-7590, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-38984432

RESUMEN

The development of new fluorescent probes as molecular sensors is a critical step for the understanding of molecular mechanisms. BODIPY-based probes offer versatility due to their high fluorescence quantum yields, photostability, and tunable absorption/emission wavelengths. Here, we report the synthesis and evaluation of a novel 7-azaindole-BODIPY derivative to probe hydrophobic proteins as well as protein misfolding and aggregation. In organic solvents, this compound shows two efficiently interconverting emissive excited states. In aqueous environments, it forms molecular aggregates with unique photophysical properties. The complex photophysics of the 7-azaindole-BODIPY derivative was explored for sensing applications. In the presence of albumin, the compound is stabilized in hydrophobic protein regions, significantly increasing its fluorescence emission intensity and lifetime. Similar effects occur in the presence of protein aggregates but not with other macromolecules like pepsin, DNA, Ficoll 40, and coconut oil. Fluorescence lifetime imaging microscopy (FLIM) and two-photon fluorescence microscopy on breast (MCF-7) and lung (A549) cancer cells incubated with this compound display longer fluorescence lifetimes and higher emission intensity under oxidative stress. Synchrotron FTIR micro spectroscopy confirmed that the photophysical changes observed were due to protein misfolding and aggregation caused by the oxidative stress. These findings demonstrate that this compound can serve as a fluorescent probe to monitor protein misfolding and aggregation triggered by oxidative stress.


Asunto(s)
Compuestos de Boro , Colorantes Fluorescentes , Estrés Oxidativo , Agregado de Proteínas , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Compuestos de Boro/química , Compuestos de Boro/síntesis química , Humanos , Indoles/química , Indoles/síntesis química , Imagen Óptica , Estructura Molecular , Microscopía Fluorescente
18.
Clin Transplant ; 27(2): 319-23, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23414365

RESUMEN

Protocol biopsies (PB) are seldom performed after pediatric kidney transplantation (KTx), and factors influencing PB results have not previously been investigated. We performed PB in 79 children six months after KTx and evaluated the results using Banff 2007 criteria. Complications such as bleeding or infections were not detected. The influence of different variables on PB results was evaluated by covariance analysis. Children treated with a low-dose calcineurin inhibitor (CNI) together with an mTOR inhibitor exhibited decreased subclinical rejection (0% vs. 19%, p = 0.001) and decreased interstitial fibrosis and tubular atrophy (IF/TA) (15% vs. 42%, p = 0.013) compared with patients treated with a conventional regimen consisting of normal-dose CNI and mycophenolate mofetil. Children with IF/TA had a lower GFR four wk after Tx (83 ± 22 vs. 62 ± 20 mL/min/1.73 m(2) , p = 0.001). Cold ischemia time, living-related donors, pre-emptive KTx, and donor age did not influence PB results. Treatment with low-dose CNI and mTOR inhibitor and high GFR directly after Tx are the main factors associated with less inflammation and fibrosis in PB and might therefore lead to better long-term graft function.


Asunto(s)
Ciclosporina/administración & dosificación , Rechazo de Injerto/patología , Inmunosupresores/administración & dosificación , Trasplante de Riñón , Riñón/patología , Tacrolimus/administración & dosificación , Adolescente , Biopsia , Niño , Preescolar , Ciclosporina/uso terapéutico , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Quimioterapia Combinada , Everolimus , Femenino , Fibrosis/etiología , Fibrosis/patología , Fibrosis/prevención & control , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/prevención & control , Supervivencia de Injerto , Humanos , Inmunosupresores/uso terapéutico , Riñón/fisiología , Masculino , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/uso terapéutico , Cuidados Posoperatorios , Complicaciones Posoperatorias/patología , Complicaciones Posoperatorias/prevención & control , Prednisolona/uso terapéutico , Sirolimus/análogos & derivados , Sirolimus/uso terapéutico , Tacrolimus/uso terapéutico , Resultado del Tratamiento
19.
Polymers (Basel) ; 15(3)2023 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-36771835

RESUMEN

The thermal imaging of surfaces with microscale spatial resolution over micro-sized areas remains a challenging and time-consuming task. Surface thermal imaging is a very important characterization tool in mechanical engineering, microelectronics, chemical process engineering, optics, microfluidics, and biochemistry processing, among others. Within the realm of electronic circuits, this technique has significant potential for investigating hot spots, power densities, and monitoring heat distributions in complementary metal-oxide-semiconductor (CMOS) platforms. We present a new technique for remote non-invasive, contactless thermal field mapping using synchrotron radiation-based Fourier-transform infrared microspectroscopy. We demonstrate a spatial resolution better than 10 um over areas on the order of 12,000 um2 measured in a polymeric thin film on top of CaF2 substrates. Thermal images were obtained from infrared spectra of poly(methyl methacrylate) thin films heated with a wire. The temperature dependence of the collected infrared spectra was analyzed via linear regression and machine learning algorithms, namely random forest and k-nearest neighbor algorithms. This approach speeds up signal analysis and allows for the generation of hyperspectral temperature maps. The results here highlight the potential of infrared absorbance to serve as a remote method for the quantitative determination of heat distribution, thermal properties, and the existence of hot spots, with implications in CMOS technologies and other electronic devices.

20.
J Colloid Interface Sci ; 638: 719-732, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36774881

RESUMEN

The maintenance of plasma membrane structure is vital for the viability of cells. Disruption of this structure can lead to cell death. One important example is the macroscopic phase separation observed during dehydration associated with desiccation and freezing, often leading to loss of permeability and cell death. It has previously been shown that the hybrid lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) can act as a line-active component in ternary lipid systems, inhibiting macroscopic phase separation and stabilising membrane microdomains in lipid vesicles [1]. The domain size is found to decrease with increasing POPC concentration until complete mixing is observed. However, no such studies have been carried out at reduced hydration. To examine if this phase separation is unique to vesicles in excess water, we have conducted studies on several binary and ternary model membrane systems at both reduced hydration ("powder" type samples and oriented membrane stacks) and in excess water (supported lipid bilayers) at 0.2 mol fraction POPC, in the range where microdomain stabilisation is reported. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) are used to map phase transition temperatures, with X-ray and neutron scattering providing details of the changes in lipid packing and phase information within these boundaries. Atomic force microscopy (AFM) is used to image bilayers on a substrate in excess water. In all cases, macroscopic phase separation was observed rather than microdomain formation at this molar ratio. Thus POPC does not stabilise microdomains under these conditions, regardless of the type of model membrane, hydration or temperature. Thus we conclude that the driving force for separation under these conditions overcomes any linactant effects of the hybrid lipid.


Asunto(s)
Membrana Dobles de Lípidos , Fosfatidilcolinas , Fosfatidilcolinas/química , Membrana Dobles de Lípidos/química , Transición de Fase , Agua
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