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1.
J Cancer Educ ; 38(1): 378-382, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-35838882

RESUMEN

Despite an estimated population of over 201 million and over 115,950 yearly diagnosed new cases of cancer, Nigeria does not have dedicated medical oncologists. Most oncology care is delivered through surgical and clinical oncologists, who are trained in both radiation and medical oncology and they number fewer than 50 in the country. With a limited number of oncology professionals, cancer patients in Nigeria experience poor health outcomes, with an estimated cancer mortality rate of 75,000 deaths per year. Participants from 15 Nigerian states were selected to attend the medical oncology training. Through the support of Fulbright Specialist Program and Project PINK BLUE, two of the authors delivered 10 days of lectures based on ASCO, ESMO, and NCCN guidelines. Mean scores of both the pre- and post-course tests as well as a 1-year follow-up test were compared using GraphPad Prism 7.0a by paired t-tests. Forty-four clinical oncologists were selected for participation. Twenty-five (57%) completed the pre- and post-course tests. Of the 25 that completed both tests, percentage of correct answers increased from 45 to 59% (2-sided p-value < 0.0001). Improvements were seen in attending doctors 45 to 59% (p = 0.0046) and resident doctors 45 to 59% (0.0007). Eleven doctors responded to the 1-year follow-up test. Although not statistically significant, a numerical pattern for the benefits was maintained 1 year after the program (45% pre-course versus 52% post-course correct answers, Fisher's exact, p = 0.4185). In the short term, the training improved medical oncology knowledge in Nigeria, regardless of the participant's carrier stage. Long-term benefits were not sustained in a small sample of participants, and continuing education strategies are necessary. Similar models may be employed across Africa.


Asunto(s)
Neoplasias , Médicos , Humanos , Nigeria , Neoplasias/tratamiento farmacológico , Oncología Médica , Personal de Salud/educación
3.
Nat Genet ; 12(2): 216-20, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8563765

RESUMEN

Cotransporters harness ion gradients to drive 'active' transport of substrates into cells, for example, the Na+/glucose cotransporter (SGLT1) couples sugar transport to Na+ gradients across the intestinal brush border. Glucose-Galactose Malabsorption (GGM) is caused by a defect in SGLT1. The phenotype is neonatal onset of diarrhea that results in death unless these sugars are removed from the diet. Previously we showed that two sisters with GGM had a missense mutation in the SGLT1 gene. The gene has now been screened in 30 new patients, and a heterologous expression system has been used to link the mutations to the phenotype.


Asunto(s)
Galactosa/metabolismo , Glucosa/metabolismo , Síndromes de Malabsorción/genética , Glicoproteínas de Membrana/genética , Proteínas de Transporte de Monosacáridos/genética , Mutación , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Transporte Biológico , Membrana Celular/fisiología , Tamización de Portadores Genéticos , Homocigoto , Humanos , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Potenciales de la Membrana , Metilglucósidos/metabolismo , Datos de Secuencia Molecular , Proteínas de Transporte de Monosacáridos/química , Proteínas de Transporte de Monosacáridos/metabolismo , Oocitos , Polimorfismo Conformacional Retorcido-Simple , Estructura Secundaria de Proteína , Transportador 1 de Sodio-Glucosa , Xenopus laevis
4.
J Endocrinol ; 257(2)2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36786578

RESUMEN

Interest in epigenetics has gained substantial momentum as a result of their identified role in the regulation of tumor progression as well as their ability to pharmacologically target genes. Pituitary neuroendocrine tumors (PitNETs) tend to be inactivated via epigenetic modification, and although emerging evidence has suggested a role for epigenetic factors in PitNET tumorigenesis, the degree to which these factors may be targeted by new therapeutic strategies still remains poorly understood. The objective of the present study was to examine the participation of the EZH2/H3K27me3 axis in the proliferation of lactotroph tumor cells. We demonstrated that the levels of EZH2 and H3K27me3 were increased in murine experimental prolactin (PRL) tumors with respect to a control pituitary, in contrast with the low p21 mRNA levels encountered, with an H3K27me3 enrichment being observed in its promoter region in a GH3 tumor cell. Furthermore, specific EZH2/H3K27me3 axis inhibition blocked the proliferation of primary tumor cell culture and GH3 cells, thereby making it an attractive therapeutic target for PRL PitNETs.


Asunto(s)
Lactotrofos , Tumores Neuroendocrinos , Neoplasias Hipofisarias , Humanos , Ratones , Animales , Histonas/metabolismo , Lactotrofos/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Línea Celular Tumoral , Epigénesis Genética , Proliferación Celular/genética , Neoplasias Hipofisarias/genética , Tumores Neuroendocrinos/genética
5.
Biomacromolecules ; 12(7): 2642-52, 2011 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-21563782

RESUMEN

The dimethyl ester of 2,3:4,5-di-O-methylene-galactaric acid (Galx) was made to react in the melt with 1,n-alkanediols HO(CH(2))(n)OH containing even numbers of methylenes (n from 6 to 12) to produce linear polycyclic polyesters. Two sets of poly(alkylene 2,3:4,5-di-O-methylene-galactarate) polyesters (PE-nGalx) with weight-average molecular weights in the ∼ 5000-10000 and ∼ 35000-45000 ranges were obtained using TBT and DBTO catalysts, respectively. For comparative purposes a set of poly(alkylene adipate) polyesters (PE-nAd) was also synthesized with molecular weights in the higher range using a similar procedure. The thermal stability of PE-nGalx was greater than that of PE-nAd although it notably decayed as molecular weight decreased. The replacement of Ad by Galx in the polyesters caused increases in T(g) of up to 70 °C, and almost doubled the tensile mechanical parameters. All PE-nGalx were semicrystalline but only those made from 1,12-dodecanediol were able to crystallize from the melt with a crystallization rate that diminished as the molecular weight increased. In general, the galactarate containing polyesters displayed higher solubility and wettability than polyadipates, they hydrolyzed faster and exhibited comparable sensitivity to the action of lipases.


Asunto(s)
Carbohidratos/química , Poliésteres/síntesis química , Azúcares Ácidos/química , Estructura Molecular , Poliésteres/química , Estereoisomerismo , Temperatura
6.
Top Curr Chem ; 295: 147-76, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21626743

RESUMEN

The low degradability of petroleum-based polymers and the massive use of these materials constitute a serious problem because of the environmental pollution that they can cause. Thus, sustained efforts have been extensively devoted to produce new polymers based on natural renewing resources and with higher degradability. Of the different natural sources, carbohydrates stand out as highly convenient raw materials because they are inexpensive, readily available, and provide great stereochemical diversity. New polymers, analogous to the more accredited technical polymers, but based on chiral monomers, have been synthesized from natural and available sugars. This chapter describes the potential of sugar-based monomers as precursors to a wide variety of macromolecular materials.

7.
Electromagn Biol Med ; 27(3): 289-97, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18821204

RESUMEN

Drug resistance is an obstacle for chemotherapy success. Because of this, this work aims to improve the cell killing effect of antineoplastic drugs by magnetic field (MF) co-exposure. S. cerevisiae cells were exposed to 2.45 mT, sinusoidal 50 Hz MF, during 48 h, and the drugs cisplatin (cisPt), mitomycin C (MMC), or methotrexate (MTX); 100 and 1,000 microg/ml. Survival was assayed by the drop test. The results showed that MF exposures do not induce alterations in the potency of cisPt, MMC, and MTX on these cells in relation to untreated controls. In addition, a strong correlation between temperature and potency of cisPt was found, which contribute to the establishment of the importance of an exhaustive control of temperature in experiments carried out with temperature sensitive antineoplastic agents in co-exposure with MF; avoiding differences between MF-exposed samples and unexposed controls and contributing to the performance of experiments under well-defined and controlled conditions.


Asunto(s)
Antineoplásicos/farmacología , Cisplatino/farmacología , Magnetismo , Metotrexato/farmacología , Mitomicina/farmacología , Saccharomyces cerevisiae/efectos de los fármacos , Resistencia a Antineoplásicos , Saccharomyces cerevisiae/citología , Temperatura
8.
Space Sci Rev ; 214(1)2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-30713357

RESUMEN

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm2 of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.

9.
J Clin Invest ; 91(6): 2844-9, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8514892

RESUMEN

Hormonal control of immunoglobulin (Ig) absorption and of intestinal Fc receptor mRNA expression were investigated in rats to assess its potential role in the normal postsuckling inhibition of this transport system. Corticosterone and L-thyroxine therapy caused premature inhibition of the absorption of orally administered murine monoclonal antibody and of Fc receptor mRNA expression in a dose- and time-dependent manner. Low-dose corticosterone had no effect on Fc receptor mRNA synthesis after 3 d but decreased Ig transport fivefold after 7 d. High dose corticosterone resulted in a threefold reduction in Fc receptor after 3 d, and there was almost complete inhibition (> 30-fold) of transport and of Fc receptor transcript levels after 7 d. Similarly, 7 d of high-dose thyroxine decreased both serum Ig transport and Fc receptor (> 30-fold). However, adrenalectomy did not prevent the normal post-suckling declines in Ig transport or receptor synthesis. This study demonstrates that exogenous corticosteroids and thyroxine hormone inhibit Ig transport and steady-state duodenal Fc receptor mRNA levels in suckling rats. Endogenous adrenal steroids however, do not appear to be entirely responsible for the age-dependent decline in this transport system.


Asunto(s)
Animales Lactantes/inmunología , Regulación de la Expresión Génica , Hormonas/farmacología , Inmunoglobulinas/metabolismo , Receptores Fc/biosíntesis , Corticoesteroides/farmacología , Adrenalectomía/efectos adversos , Animales , Secuencia de Bases , Transporte Biológico , Datos de Secuencia Molecular , ARN Mensajero/biosíntesis , Ratas , Ratas Sprague-Dawley , Receptores Fc/genética , Hormonas Tiroideas/farmacología
10.
Brain Struct Funct ; 222(6): 2547-2558, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28283747

RESUMEN

The pedunculopontine nucleus (PPN) has been proposed as target for deep brain stimulation (DBS) in patients with postural instability and gait disorders due to its involvement in muscle tonus adjustments and control of locomotion. However, it is a deep-seated brainstem nucleus without clear imaging or electrophysiological markers. Some studies suggested that diffusion tensor imaging (DTI) may help guiding electrode placement in the PPN by showing the surrounding fiber bundles, but none have provided a direct histological correlation. We investigated DTI fractional anisotropy (FA) maps from in vivo and in situ post-mortem magnetic resonance images (MRI) compared to histological evaluations for improving PPN targeting in humans. A post-mortem brain was scanned in a clinical 3T MR system in situ. Thereafter, the brain was processed with a special method ideally suited for cytoarchitectonic analyses. Also, nine volunteers had in vivo brain scanning using the same MRI protocol. Images from volunteers were compared to those obtained in the post-mortem study. FA values of the volunteers were obtained from PPN, inferior colliculus, cerebellar crossing fibers and medial lemniscus using histological data and atlas information. FA values in the PPN were significantly lower than in the surrounding white matter region and higher than in areas with predominantly gray matter. In Nissl-stained histologic sections, the PPN extended for more than 10 mm in the rostro-caudal axis being closely attached to the lateral parabrachial nucleus. Our DTI analyses and the spatial correlation with histological findings proposed a location for PPN that matched the position assigned to this nucleus in the literature. Coregistration of neuroimaging and cytoarchitectonic features can add value to help establishing functional architectonics of the PPN and facilitate neurosurgical targeting of this extended nucleus.


Asunto(s)
Imagen de Difusión Tensora/métodos , Imagen por Resonancia Magnética/métodos , Núcleo Tegmental Pedunculopontino/diagnóstico por imagen , Núcleo Tegmental Pedunculopontino/patología , Adulto , Anciano , Puntos Anatómicos de Referencia , Anisotropía , Autopsia , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Adulto Joven
11.
AJNR Am J Neuroradiol ; 27(4): 843-9, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16611776

RESUMEN

BACKGROUND AND PURPOSE: Single-shot, fast spin-echo, fluid attenuated inversion recovery (SS-FSE-FLAIR) images are frequently used to detect disease in the brain and subarachnoid space in confused or uncooperative patients who may move during the examination. In some of these patients, high signal intensity areas are seen on good-quality images in the subarachnoid space and ventricular system in locations not associated with high CSF flow. These artifacts may simulate hemorrhage or leptomeningeal disease. The purpose of this article was to determine the cause of these artifacts, describe ways to recognize them, and find methods to reduce or eliminate them. METHODS: Healthy volunteers were studied on 6 occasions with conventional multisection FSE-FLAIR images and SS-FSE-FLAIR images while at rest and while nodding and rotating their heads at different speeds. In addition, SS-FSE-FLAIR images with different section widths of the initial inverting pulse and a non-section-selective initial inversion pulse were performed with the subjects moving their heads in the same way. The scans of 30 successive patients with acute neurologic syndromes who had been studied with SS-FSE-FLAIR sequences were reviewed for evidence of high signal intensity in the CSF in regions not associated with high CSF flow. RESULTS: Each of the volunteers showed areas of increased signal intensity in CSF at sites apart from those associated with rapid pulsatile CSF flow on SS-FSE-FLAIR images acquired during head motion. The images were otherwise virtually free of motion artifact. The use of a wider initial inversion pulse section and a non-section-selected initial inversion pulse reduced the extent of these artifacts. Nineteen of the 30 patients showed areas of high signal intensity in the CSF in regions not associated with highly pulsatile CSF flow. Six of these patients had negative lumbar punctures for blood and xanthochromia and normal CSF protein levels. CONCLUSION: High signal intensity artifacts may be seen in CSF as a result of head movement on otherwise artifact-free images when imaging uncooperative patients with SS-FSE-FLAIR sequences. These artifacts have a different mechanism and distribution from those caused by CSF pulsation and may simulate subarachnoid and intraventricular hemorrhage. Artifact recognition is aided by signs of patient motion during the examination. The artifacts can be reduced by use of increased section width and non-section-selective initial inversion pulses. Recognition of these artifacts is important, because the circumstances in which the SS-FSE-FLAIR sequence is used and the particular properties of the sequence may conspire to produce a trap for the unwary.


Asunto(s)
Artefactos , Hemorragia Cerebral/diagnóstico , Ventrículos Cerebrales , Imagen por Resonancia Magnética , Hemorragia Subaracnoidea/diagnóstico , Adulto , Diagnóstico Diferencial , Cabeza , Humanos , Movimiento
12.
Prog Mol Biol Transl Sci ; 140: 47-74, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27288825

RESUMEN

PCSK1, encoding prohormone convertase 1/3 (PC1/3), was one of the first genes linked to monogenic early-onset obesity. PC1/3 is a protease involved in the biosynthetic processing of a variety of neuropeptides and prohormones in endocrine tissues. PC1/3 activity is essential for the activating cleavage of many peptide hormone precursors implicated in the regulation of food ingestion, glucose homeostasis, and energy homeostasis, for example, proopiomelanocortin, proinsulin, proglucagon, and proghrelin. A large number of genome-wide association studies in a variety of different populations have now firmly established a link between three PCSK1 polymorphisms frequent in the population and increased risk of obesity. Human subjects with PC1/3 deficiency, a rare autosomal-recessive disorder caused by the presence of loss-of-function mutations in both alleles, are obese and display a complex set of endocrinopathies. Increasing numbers of genetic diagnoses of infants with persistent diarrhea has recently led to the finding of many novel PCSK1 mutations. PCSK1-deficient infants experience severe intestinal malabsorption during the first years of life, requiring controlled nutrition; these children then become hyperphagic, with associated obesity. The biochemical characterization of novel loss-of-function PCSK1 mutations has resulted in the discovery of new pathological mechanisms affecting the cell biology of the endocrine cell beyond simple loss of enzyme activity, for example, dominant-negative effects of certain mutants on wild-type PC1/3 protein, and activation of the cellular unfolded protein response by endoplasmic reticulum-retained mutants. A better understanding of these molecular and cellular pathologies may illuminate possible treatments for the complex endocrinopathy of PCSK1 deficiency, including obesity.


Asunto(s)
Obesidad/genética , Obesidad/patología , Polimorfismo de Nucleótido Simple/genética , Proproteína Convertasa 1/genética , Humanos
13.
Biochim Biophys Acta ; 1453(2): 297-303, 1999 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-10036327

RESUMEN

Glucose-galactose malabsorption (GGM) is an autosomal recessive disorder caused by defects in the Na+/glucose cotransporter (SGLT1). Neonates present with severe diarrhea while on any diet containing glucose and/or galactose [1]. This study focuses on a patient of Swiss and Dominican descent. All 15 exons of SGLT1 were screened using single stranded conformational polymorphism analyses, and aberrant PCR products were sequenced. Two missense mutations, Gly318Arg and Ala468Val, were identified. SGLT1 mutants were expressed in Xenopus laevis oocytes for radiotracer uptake, electrophysiological experiments, and Western blotting. Uptakes of [14C]alpha-methyl-d-glucoside by the mutants were 5% or less than that of wild-type. Two-electrode voltage-clamp experiments confirmed the transport defects, as no noticeable sugar-induced current could be elicited from either mutant [2]. Western blots of cell protein showed levels of each SGLT1 mutant protein comparable to that of wild-type, and that both were core-glycosylated. Presteady-state current measurements indicated an absence of SGLT1 in the plasma membrane. We suggest that the compound heterozygote missense mutations G318R and A468V lead to GGM in this patient by defective trafficking of mutant proteins from the endoplasmic reticulum to the plasma membrane.


Asunto(s)
Galactosa/metabolismo , Glucosa/metabolismo , Síndromes de Malabsorción/genética , Glicoproteínas de Membrana/genética , Proteínas de Transporte de Monosacáridos/genética , Membrana Celular/metabolismo , Retículo Endoplásmico/metabolismo , Femenino , Humanos , Recién Nacido , Síndromes de Malabsorción/metabolismo , Glicoproteínas de Membrana/química , Proteínas de Transporte de Monosacáridos/química , Mutación , Polimorfismo Conformacional Retorcido-Simple , Transportador 1 de Sodio-Glucosa
14.
Braz J Med Biol Res ; 38(12): 1847-56, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16302099

RESUMEN

According to the concepts of cognitive neuropsychology, there are two principal routes of reading processing: a lexical route, in which global reading of words occurs and a phonological route, responsible for the conversion of the graphemes into their respective phonemes. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the patterns of cerebral activation in lexical and phonological reading by 13 healthy women with a formal educational level greater than 11 years. Participants were submitted to a silent reading task containing three types of stimuli: real words (irregular and foreign words), nonwords and illegitimate graphic stimuli. An increased number of activated voxels were identified by fMRI in the word reading (lexical processing) than in the nonword reading (phonological processing) task. In word reading, activation was greater than for nonwords in the following areas: superior, middle and inferior frontal gyri, and bilateral superior temporal gyrus, right cerebellum and the left precentral gyrus, as indicated by fMRI. In the reading of nonwords, the activation was predominant in the right cerebellum and in the left superior temporal gyrus. The results of the present study suggest the existence of differences in the patterns of cerebral activation during lexical and phonological reading, with greater involvement of the right hemisphere in reading words than nonwords.


Asunto(s)
Mapeo Encefálico , Lenguaje , Vías Nerviosas/fisiología , Lectura , Adolescente , Adulto , Mapeo Encefálico/métodos , Femenino , Humanos , Imagen por Resonancia Magnética/métodos
16.
J Geophys Res Planets ; 120(3): 495-514, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26690960

RESUMEN

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C2 to C4 dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles. KEY POINTS: First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

17.
Gene ; 201(1-2): 189-97, 1997 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-9409786

RESUMEN

The role of the polymeric receptor (pIgR) is to transport polymeric IgA across various mucosal epithelial layers. Although several mammalian pIgR cDNAs, including mouse, have been cloned, genomic structure has only been partially analyzed in the human, and neither its 5'-upstream region nor its transcriptional start site is known. We report the isolation and characterization of the murine pIgR gene that spans 32 kb and contains 11 exons. The general organization of the murine gene, including its intron/exon boundaries was similar to its human homolog; however, the second intron was 7.2 kb in the mouse vs. only 0.8 kb in humans. Primer extension and 5'-RACE independently identified the identical transcriptional initiation site. Sequence analysis of 350 base pairs in the 5'-flanking region revealed several motifs, including a TATA box, and putative interferon-gamma, HNF-3beta and AP1 sites. In summary, we have isolated the murine pIgR gene and described its structure and organization.


Asunto(s)
Regiones Promotoras Genéticas , Receptores de Inmunoglobulina Polimérica/genética , Animales , Secuencia de Bases , Southern Blotting , Clonación Molecular , ADN Complementario , Humanos , Ratones , Datos de Secuencia Molecular , Transcripción Genética
18.
Transplantation ; 70(1): 94-9, 2000 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-10919581

RESUMEN

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) is a serious complication associated with the use of chronic immunosuppression for solid organ transplantation. This study represents a retrospective analysis of UCLA's experience with PTLD in all pediatric liver transplant recipients between 1984-1997. We assessed the clinical presentation, risk factors, incidence density, immunological characteristics, management, and outcome of patients who developed PTLD when receiving either primary cyclosporin A (CsA) or tacrolimus. METHODS: A total of 251 children received primary CsA therapy of which 70 required OKT3 for steroid resistant rejection and 29 required tacrolimus rescue for OKT3 resistance and/or chronic rejection. One hundred forty one children received tacrolimus as primary therapy. Sixty patients who survived for less than 6 months after transplantation were excluded from the study. RESULTS: The total incidence density (ID) rate of PTLD was 1.8+/-0.4 per 100 patient-years (30/392). The overall ID rate of PTLD in the CsA group was 0.93+/-0.2 per 100 patient-years (15/251). Within this group of primary CsA-treated patients, the ID rate of PTLD was 0.49+/-0.1 without OKT3 or tacrolimus, 0.67+/-0.2 with OKT3, and 6.42+/-1.1 with tacrolimus rescue. The overall PTLD ID rate in the primary tacrolimus-treated patients was 4.86+/-1.2 per 100 person-years (15/141). There was a 5-fold increase in the ID rate of PTLD in the primary tacrolimus group when compared to the comparable, primary CsA group (P<0.001). The mean time to PTLD was 5-fold longer (49.7+/-20.7 months) in the CsA group when compared to the CsA/tacrolimus rescue group (9.8+/-3 months, P<0.05) or the tacrolimus primary group (12.6+/-5.1 months, P<0.05). Five patients had monoclonal disease in the CsA group, but only one in the tacrolimus group (P<0.05). Clinical presentations with enlarged lymph nodes, fevers, malaise, anorexia, weight loss, hypoalbuminemia, and gastrointestinal blood loss were common. Mortality was 20%, three patients died in each group. CONCLUSION: The use of primary tacrolimus therapy was associated with a significant 5-fold higher rate of PTLD when compared to those treated with primary cyclosporine. Early diagnosis, decrease and/or discontinuation of potent immunosuppressive agents may contribute to decrease morbidity and mortality of this entity.


Asunto(s)
Inmunosupresores/efectos adversos , Trasplante de Hígado/efectos adversos , Trastornos Linfoproliferativos/etiología , Adolescente , Factores de Edad , Niño , Preescolar , Ciclosporina/efectos adversos , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Incidencia , Lactante , Trastornos Linfoproliferativos/epidemiología , Trastornos Linfoproliferativos/terapia , Muromonab-CD3/efectos adversos , Estudios Retrospectivos , Factores de Riesgo , Tacrolimus/efectos adversos
19.
Transplantation ; 67(3): 404-11, 1999 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-10030286

RESUMEN

BACKGROUND: Poor linear growth after pediatric orthotopic liver transplantation (OLT) is a well-described phenomenon. We have undertaken a bivariate and multivariate analysis of multiple factors that might effect postOLT growth in all children who underwent transplantation at a single center, with survival > 1 year and adequate follow-up. METHODS: Standardized height score (Z score) and height deficit (centimeters below the 50th percentile) were computed for each patient over time. The variables assessed were (i) age at OLT, (ii) gender, (iii) pretransplantation diagnosis, (iv) Z score and height deficit at OLT, (v) tacrolimus versus cyclosporine as primary immunosuppressive therapy, (vi) retransplantation, (vii) graft disease, (viii) chronic illness, (ix) posttransplant lymphoproliferative disease, (x) intractable rejection, and (xi) prednisone withdrawal. RESULTS: A total of 236 children met the inclusion criteria, with a mean follow-up of 3.8+/-1.9 years. For the population as a whole, the baseline Z score was -1.72 (fourth percentile) with a significant improvement to - 1.37 (ninth percentile) at 2 years, but with no additional gain at 5 years (Z score -1.4). The baseline height deficit was -6.4 cm, with no improvement at 2 years (-6.52 cm), and was significantly worse at 5 years (-7.87 cm). In the bivariate analysis, the most important variables affecting growth were age at OLT, Z score at OLT, and diagnosis. In general, children <2 years with biliary atresia and those with the most growth delay at OLT showed the best posttransplantation growth. In the multivariate analysis, 18 factors were considered, of which 9 were significant. These were (i) Z score at baseline, (ii) follow-up time, (iii) age at OLT, (iv) diagnosis of tumor, (v) diagnosis of fulminant hepatic failure, (vi) retransplantation, (vii) graft disease, (viii) posttransplant lymphoproliferative disease, and (ix) stoppage of prednisone. Multivariate models using these nine variables accounted for 84% of the variation in standardized height. CONCLUSION: In general, children after OLT show some potential for catch-up growth but do not achieve normal height compared with their age and sex-matched peers. A multivariate analysis was necessary to investigate the interdependent effects of the many variables that can affect growth after OLT. The most important detrimental affects were older age at time of OLT, Z scores greater than -2.0 at OLT, fulminant hepatic failure, tumor, and postOLT complications causing graft dysfunction.


Asunto(s)
Estatura , Crecimiento/fisiología , Trasplante de Hígado/fisiología , Adolescente , Factores de Edad , Niño , Preescolar , Ciclosporina/uso terapéutico , Femenino , Estudios de Seguimiento , Registros de Hospitales , Humanos , Inmunosupresores/uso terapéutico , Lactante , Masculino , Complicaciones Posoperatorias , Reoperación , Estudios Retrospectivos , Factores Sexuales , Análisis de Supervivencia , Tacrolimus/uso terapéutico , Factores de Tiempo
20.
Transplantation ; 66(3): 311-8, 1998 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-9721798

RESUMEN

BACKGROUND: We describe the incidence, results of interferon therapy, and outcome of hepatitis C virus (HCV) hepatitis occurring de novo after pediatric orthotopic liver transplantation (OLT). METHODS AND RESULTS: Of children undergoing OLT between 1984 and September 1996, 321 children survived for more than 1 year. Of these, 13 (4.0%) developed previously undiagnosed HCV disease, as suggested by HCV antibody testing and HCV polymerase chain reaction and confirmed by liver biopsy. Of the 117 children who received transplants before HCV screening of blood products or donors, 10.2% developed de novo HCV disease. The mean age at diagnosis of HCV hepatitis was 13.2+/-5.0 years, and the mean time to diagnosis after OLT was 8.1 years (range, 4-11 years). The mean alanine aminotransferase (ALT) level at diagnosis was 108 IU/ml, and the liver biopsy specimen showed chronic active or chronic persistent hepatitis in 11 children, cirrhosis in 1 child, and nonspecific changes in 1 child. Twelve children were treated with interferon-2alpha; children who weighed > or =20 kg received 3 x 10(6) units every other day, and those who weighed <20 kg received 1.5 x 10(6) units every other day. Four patients developed rapidly progressive liver failure while receiving interferon therapy and required urgent re-transplantation. Three of the four children again developed histologic evidence of recurrent HCV 4-6 months after the second OLT, and all three subsequently died of HCV-induced liver failure. One patient remains alive and well with no evidence of HCV recurrence and a negative HCV RNA. Of the remaining eight children treated with interferon, only two have had a sustained response (normal ALT) and one is now HCV RNA negative. HCV RNA levels did not correlate with outcome or disease severity. HCV antibody levels were unreliable, with two patients having negative HCV antibody but a positive HCV RNA at diagnosis. Six patients were able to be genotyped: four were la and two were 1b. CONCLUSION: Overall mortality for de novo HCV hepatitis was 23%. Seventy-five percent of children who received a second transplant for HCV hepatitis had early histologic recurrence that led to liver failure and death. Interferon therapy resulted in a sustained improvement in ALT in only 15% of children. The time to onset and progression of clinical disease both in the original graft and the retransplant graft were accelerated compared with nonimmunosuppressed individuals.


Asunto(s)
Hepatitis C Crónica/diagnóstico , Trasplante de Hígado , Complicaciones Posoperatorias/diagnóstico , Adolescente , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Estudios de Seguimiento , Anticuerpos contra la Hepatitis C/sangre , Hepatitis C Crónica/inmunología , Hepatitis C Crónica/terapia , Humanos , Interferón alfa-2 , Interferón-alfa/uso terapéutico , Masculino , Reacción en Cadena de la Polimerasa , Complicaciones Posoperatorias/inmunología , Complicaciones Posoperatorias/terapia , ARN Viral/sangre , Proteínas Recombinantes , Recurrencia , Resultado del Tratamiento
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