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1.
Pediatr Transplant ; 22(1)2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29218760

RESUMEN

Non-adherence to immunosuppressant medications is an important risk factor for graft dysfunction. To evaluate the effectiveness of adherence-enhancing interventions, we reviewed adherence intervention studies in solid organ transplant recipients (all ages). Using the following databases: PsycINFO, PubMed, Scopus, and ScienceDirect, we identified 41 eligible studies. Only three non-randomized trials showed a possible positive effect on objective indicators of transplant outcomes (such as rejection, liver enzyme levels, kidney function). None of the 21 RCTs showed an improvement in transplant outcomes. Three studies showed a higher rate of adverse events in the intervention group as compared with controls, although this may be related to ascertainment bias. Improvement in adherence as measured indirectly (eg, with electronic monitoring devices) was not aligned with effects on transplant outcomes. We conclude that adherence interventions, to date, have largely been ineffective in improving transplant outcomes. To improve this track record, intervention efforts may wish to concentrate on non-adherent patients (rather than use convenience sampling, which excludes many of the patients who need the intervention), use direct measures of adherence to guide the interventions, and employ strategies that are intensive and yet engaging enough to ensure that non-adherent patients are able to participate.


Asunto(s)
Rechazo de Injerto/prevención & control , Inmunosupresores/uso terapéutico , Cumplimiento de la Medicación , Trasplante de Órganos , Humanos , Resultado del Tratamiento
2.
Am J Transplant ; 17(10): 2668-2678, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28321975

RESUMEN

Nonadherence to immunosuppressant medications is a leading cause of poor long-term outcomes in transplant recipients. The Medication Level Variability Index (MLVI) provides a vehicle for transplant outcome risk-stratification through continuous assessment of adherence. The MALT (Medication Adherence in children who had a Liver Transplant) prospective multi-site study evaluated whether MLVI predicts late acute rejection (LAR). Four hundred pediatric (1-17-year-old) liver transplant recipients were enrolled and followed for 2 years. The a-priori hypothesis was that a higher MLVI predicts LAR. Predefined secondary analyses evaluated other outcomes such as liver enzyme levels, and sensitivity analyses compared adolescents to pre-adolescents. In the primary analysis sample of 379 participants, a higher prerejection MLVI predicted LAR (mean prerejection MLVI with LAR: 2.4 [3.6 standard deviation] versus without LAR, 1.6 [1.1]; p = 0.026). Fifty-three percent of the adolescents with MLVI>2 in year 1 had LAR by the end of year 2, as compared with 6% of those with year 1 MLVI≤2. A higher MLVI was significantly associated with all secondary outcomes. MLVI, a marker of medication adherence that uses clinically derived information, predicts LAR in pediatric liver transplant recipients.


Asunto(s)
Inmunosupresores/administración & dosificación , Trasplante de Hígado , Cooperación del Paciente , Adolescente , Niño , Preescolar , Estudios de Cohortes , Rechazo de Injerto , Humanos , Inmunosupresores/sangre , Lactante , Estudios Prospectivos , Tacrolimus/administración & dosificación , Tacrolimus/sangre , Resultado del Tratamiento
3.
Genet Mol Res ; 15(2)2016 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-27173316

RESUMEN

Acrocomia aculeata is a plant rich in antioxidant compounds. Studies suggest that this plant has anti-inflammatory, antidiabetic, and diuretic potential. We assessed the antigenotoxic, antimutagenic, immunomodulation, and apoptotic potentials of A. aculeata alone and in combination with an antitumor agent, cyclophosphamide. Swiss male mice (N = 140) were used. The animals were divided into 14 experimental groups as follows: a negative group, a positive group (100 mg/kg cyclophosphamide), groups that only received the oil extracted from the almond (AO) and from the pulp (PO) of A. aculeata at doses of 3, 15, and 30 mg/kg, and the associated treatment groups (oils combined with cyclophosphamide) involving pretreatment, simultaneous, and post-treatment protocols. Data suggest that both oils were chemopreventive at all doses, based on the tested protocols. The highest damage reduction percentages, observed for AO and PO were 88.19 and 90.03%, respectively, for the comet assay and 69.73 and 70.93%, respectively, for the micronucleus assay. Both AO and PO demonstrated immunomodulatory activity. The oils reduced the capacity of cyclophosphamide to trigger apoptosis in the liver, spleen, and kidney cells. These results suggest that A. aculeate AO and PO can be classified as a functional food and also enrich other functional foods and nutraceuticals with chemopreventive features. However, they are not appropriate sources for chemotherapeutic adjuvants, in particular for those used in combination with cyclophosphamide.


Asunto(s)
Antineoplásicos/toxicidad , Antioxidantes/farmacología , Arecaceae/química , Ciclofosfamida/toxicidad , Daño del ADN , Extractos Vegetales/farmacología , Animales , Apoptosis , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Masculino , Ratones , Bazo/efectos de los fármacos
4.
J Dairy Sci ; 92(5): 2306-16, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19389989

RESUMEN

Engineering tools and mathematical optimization are applied in this study to plan the work of the agents of the cow artificial insemination service (inseminator) in Israel. Time is crucial in insemination as the chances of conception decline with increasing delay between the start of estrus and insemination. About 1,090 artificial inseminations of cows are performed daily in Israel. They involve 412 farms in 283 villages, and are performed by 29 inseminators; the work plan should balance the work load among the inseminators. To this end, the working time of an inseminator in each village is required. Thus, a model to predict the working time in a village was developed. Subsequently, a mathematical optimization model was designed and solved, which aims to allocate customers to trips and to determine the itinerary of each trip to minimize total distance/time. The main benefits included a 21.4% reduction in total traveling time and a 55% reduction in the difference between the lengths of the longest and shortest working days. Moreover, the longest delay in reaching an estrous cow is reduced from 7.6 to 5.9 h (i.e., by 1.7 h), which may increase the conception ratio by some 7%. In addition, the trade-off between work balance and total traveling time was studied.


Asunto(s)
Crianza de Animales Domésticos/métodos , Inseminación Artificial/veterinaria , Modelos Biológicos , Animales , Bovinos , Femenino , Humanos , Inseminación Artificial/métodos , Israel , Embarazo , Análisis de Regresión , Reproducibilidad de los Resultados , Factores de Tiempo , Recursos Humanos , Carga de Trabajo
5.
Pediatr Transplant ; 12(3): 316-23, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18435607

RESUMEN

We describe results from a clinical program, which aimed at improving adherence to medications in children who had a liver transplant. We followed the medical outcomes of 23 children and adolescents who participated in a clinical adherence-improvement protocol during the years 2001-2002. The protocol included identification of non-adherent patients by examining tacrolimus blood levels and intervention by increasing the frequency of clinic visits for non-adherent patients. In the two-yr preintervention (1999-2000), there was no improvement in any of the outcomes. After the intervention, the number of patients with high alanine aminotransferase levels (100 and above) decreased significantly, from eight before the intervention to four afterwards. Other outcomes, including the number of rejection episodes (three before, none after) and the degree of adherence to tacrolimus, also improved, but the improvement did not reach statistical significance. Although non-adherent patients were called to clinic more often under the protocol, the intervention did not lead to increased outpatient costs. This adherence--improvement intervention appears to be promising in improving outcomes in pediatric liver transplant recipients. Larger, controlled studies are needed to establish the efficacy of this or other approaches.


Asunto(s)
Trasplante de Hígado/métodos , Cooperación del Paciente , Adolescente , Adulto , Alanina Transaminasa/metabolismo , Niño , Femenino , Rechazo de Injerto/prevención & control , Humanos , Inmunosupresores/sangre , Inmunosupresores/uso terapéutico , Trasplante de Hígado/economía , Masculino , Pediatría/métodos , Autoadministración , Tacrolimus/sangre , Tacrolimus/uso terapéutico , Resultado del Tratamiento
6.
Am J Transplant ; 8(4 Pt 2): 935-45, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18336697

RESUMEN

This article represents the sixth annual review of the current state of pediatric transplantation in the United States from the Scientific Registry of Transplant Recipients (SRTR). It presents updated trends, discussion of analyses presented during the year by the SRTR to the committees of the Organ Procurement and Transplantation Network (OPTN) and discussion of important issues currently facing pediatric organ transplantation. Unless otherwise stated, the statistics in this article are drawn from the reference tables of the 2007 OPTN/SRTR Annual Report. In this article, pediatric patients are defined as candidates, recipients or donors aged 17 years or less. Data for both graft and patient survival are reported as unadjusted survival, unless otherwise stated (adjusted patient and graft survival are available in the reference tables). Short-term survival (3 month and 1 year) reflects outcomes for transplants performed in 2004 and 2005; 3-year survival reflects transplants from 2002 to 2005; and 5-year survival reports on transplants performed from 2000 to 2005. Details on the methods of analysis employed may be found in the reference tables themselves or in the technical notes of the 2007 OTPN/SRTR Annual Report, both available online at http://www.ustransplant.org.


Asunto(s)
Trasplante/estadística & datos numéricos , Adolescente , Adulto , Niño , Preescolar , Estudios de Seguimiento , Trasplante de Corazón/estadística & datos numéricos , Humanos , Intestinos/trasplante , Trasplante de Riñón/estadística & datos numéricos , Trasplante de Hígado/estadística & datos numéricos , Persona de Mediana Edad , Selección de Paciente , Sistema de Registros , Análisis de Supervivencia , Factores de Tiempo , Donantes de Tejidos/estadística & datos numéricos , Trasplante/tendencias , Estados Unidos , Listas de Espera
8.
Am J Transplant ; 6(8): 1906-12, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16889546

RESUMEN

A randomized controlled trial of CMV-IVIG (cytomegalovirus-intravenous immunoglobulin) for prevention of Epstein Barr virus (EBV) posttransplant lymphoproliferative disease (PTLD) in pediatric liver transplantation (PLTx) recipients was begun in Pittsburgh and subsequently expanded to four additional sites. Protocol EB viral loads were obtained in a blinded fashion; additional loads could be obtained for clinical indications. Patients were followed for 2 years post-LTx. Eighty-two evaluable patients (39 CMV-IVIG, 43 placebo) developed 18 episodes of EBV disease (7 CMV-IVIG, 11 placebo) including nine cases of PTLD (three CMV-IVIG, six placebo). No significant differences were seen in the adjusted 2-year EBV disease-free rate (CMV-IVIG 79%, placebo 71%) and PTLD-free rate (CMV-IVIG 91%, placebo 84%) between treatment and placebo groups at 2 years (p > 0.20). The absence of significant effect of CMV-IVIG may be explained by a lack of efficacy of the drug or limitations of sample size.


Asunto(s)
Citomegalovirus/inmunología , Infecciones por Virus de Epstein-Barr/prevención & control , Herpesvirus Humano 4/efectos de los fármacos , Herpesvirus Humano 4/inmunología , Inmunoglobulinas/farmacología , Trasplante de Hígado , Trastornos Linfoproliferativos/cirugía , Adolescente , Niño , Preescolar , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/inmunología , Femenino , Estudios de Seguimiento , Humanos , Inmunoglobulinas/administración & dosificación , Inmunoglobulinas/inmunología , Lactante , Infusiones Intravenosas , Trastornos Linfoproliferativos/complicaciones , Trastornos Linfoproliferativos/inmunología , Trastornos Linfoproliferativos/virología , Masculino , Tasa de Supervivencia , Resultado del Tratamiento
9.
Am J Transplant ; 6(8): 1948-52, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16889549

RESUMEN

A male child initially presented with atypical hemolytic uremic syndrome (HUS) at the age of 4 months and progressed within weeks to end stage renal disease (ESRD). At the age of 2 years he received a live-related kidney transplant from his mother, which, despite initial good function, was lost to recurrent disease after 2 weeks. Complement factor H analysis showed low serum levels and the presence of two mutations on different alleles (c.2918G > A, Cys973Tyr and c.3590T > C, Val1197Ala). His survival on dialysis was at risk because of access failure and recurrent bacteremic episodes. Therefore, at the age of 5 years he received a combined liver-kidney transplant with pre-operative plasma exchange. Initial function of both grafts was excellent and this has been maintained for over 2 years. This report suggests that despite setbacks in previous experience, combined liver-kidney transplantation offers the prospect of a favorable long-term outcome for patients with HUS associated with complement factor H mutations.


Asunto(s)
Factor H de Complemento/genética , Síndrome Hemolítico-Urémico/genética , Síndrome Hemolítico-Urémico/patología , Trasplante de Riñón , Trasplante de Hígado , Preescolar , Humanos , Lactante , Masculino , Mutación/genética , Recurrencia , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
10.
J Lipid Res ; 44(9): 1643-51, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12810826

RESUMEN

5alpha-Cyprinol sulfate was isolated from bile of the Asiatic carp, Cyprinus carpio. 5alpha-Cyprinol sulfate was surface active and formed micelles; its critical micellization concentration (CMC) in 0.15 M Na+ using the maximum bubble pressure device was 1.5 mM; by dye solubilization, its CMC was approximately 4 mM. At concentrations >1 mM, 5alpha-cyprinol sulfate solubilized monooleylglycerol efficiently (2.1 molecules per mol micellar bile salt). When infused intravenously into the anesthetized rat, 5alpha-cyprinol sulfate was hemolytic, cholestatic, and toxic. In the isolated rat liver, it underwent little biotransformation and was poorly transported (Tmax congruent with 0.5 micromol/min/kg) as compared with taurocholate. 5alpha-Cyprinol, its bile alcohol moiety, was oxidized to its corresponding C27 bile acid and to allocholic acid (the latter was then conjugated with taurine); these metabolites were efficiently transported. 5alpha-Cyprinol sulfate inhibited taurocholate uptake in COS-7 cells transfected with rat asbt, the apical bile salt transporter of the ileal enterocyte. 5alpha-Cyprinol had limited aqueous solubility (0.3 mM) and was poorly absorbed from the perfused rat jejunum or ileum. Sampling of carp intestinal content indicated that 5alpha-cyprinol sulfate was present at micellar concentrations, and that it did not undergo hydrolysis during intestinal transit. These studies indicate that 5alpha-cyprinol sulfate is an excellent digestive detergent and suggest that a micellar phase is present during digestion in cyprinid fish.


Asunto(s)
Ácidos y Sales Biliares/química , Ácidos y Sales Biliares/metabolismo , Colestanoles/química , Colestanoles/metabolismo , Animales , Bilis/química , Ácidos y Sales Biliares/aislamiento & purificación , Ácidos y Sales Biliares/toxicidad , Transporte Biológico , Biotransformación , Carpas/metabolismo , Línea Celular , Colestanoles/aislamiento & purificación , Colestanoles/toxicidad , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Hígado/metabolismo , Estructura Molecular , Perfusión , Ratas , Espectrometría de Masa por Ionización de Electrospray , Tensión Superficial
12.
J Pediatr Gastroenterol Nutr ; 33(4): 445-9, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11698761

RESUMEN

BACKGROUND: Risk factors for the development of posttransplant lymphoproliferative disease (PTLD), a major cause of morbidity and mortality after pediatric liver transplantation, are primary Epstein-Barr virus (EBV) infection and intensity of immunosuppression. The authors assessed monitoring of EBV replication and preemptive immunosuppression reduction in pediatric liver transplant recipients. METHODS: The authors prospectively followed monthly EBV-quantitative competitive polymerase chain reaction to measure EBV replication in 23 patients who underwent liver transplant between July 1997 and November 1998. Preemptive immunosuppression reduction was instituted for significant EBV replication. Patients were followed up for at least 1 year and divided in two groups for analysis (group 1, pretransplant seronegative for EBV [13 patients]; group 2, seropositive for EBV [10 patients]). RESULTS: In group 1, 9 of 13 patients had positive polymerase chain reaction results at a mean time of 22.4 weeks after transplantation. All but one of these patients were asymptomatic. In seven of nine patients, preemptive immunosuppression reduction was undertaken without development of PTLD or rejection. In two of nine patients, immunosuppression could not be continuously reduced, and both patients experienced low-grade and medically responsive PTLD. In no patient in group 2 did an EBV-positive viral load or PTLD develop. CONCLUSIONS: Prospective longitudinal measurement of EBV by quantitative competitive polymerase chain reaction permits early detection of asymptomatic viral replication. Subsequent preemptive reduction of immunosuppression may prevent the progression to PTLD.


Asunto(s)
Infecciones por Virus de Epstein-Barr/complicaciones , Trastornos Linfoproliferativos/etiología , Trastornos Linfoproliferativos/prevención & control , Trasplante de Órganos/efectos adversos , Complicaciones Posoperatorias/etiología , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Infecciones por Virus de Epstein-Barr/transmisión , Resultado Fatal , Femenino , Rechazo de Injerto/prevención & control , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Terapia de Inmunosupresión/efectos adversos , Inmunosupresores/administración & dosificación , Lactante , Recién Nacido , Trastornos Linfoproliferativos/virología , Masculino , Reacción en Cadena de la Polimerasa , Complicaciones Posoperatorias/virología , Estudios Prospectivos , Factores de Riesgo , Tacrolimus/administración & dosificación , Carga Viral
14.
Ann Surg ; 234(3): 301-11; discussion 311-2, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11524583

RESUMEN

OBJECTIVE: To summarize the evolution of a living donor liver transplant program and the authors' experience with 109 cases. SUMMARY BACKGROUND DATA: The authors' institution began to offer living donor liver transplants to children in 1993 and to adults in 1998. METHODS: Donors were healthy, ages 18 to 60 years, related or unrelated, and ABO-compatible (except in one case). Donor evaluation was thorough. Liver biopsy was performed for abnormal lipid profiles or a history of significant alcohol use, a body mass index more than 28, or suspected steatosis. Imaging studies included angiography, computed tomography, endoscopic retrograde cholangiopancreatography, and magnetic resonance imaging. Recipient evaluation and management were the same as for cadaveric transplant. RESULTS: After ABO screening, 136 potential donors were evaluated for 113 recipients; 23 donors withdrew for medical or personal reasons. Four donor surgeries were aborted; 109 transplants were performed. Fifty children (18 years or younger) received 47 left lateral segments and 3 left lobes; 59 adults received 50 right lobes and 9 left lobes. The average donor hospital stay was 6 days. Two donors each required one unit of banked blood. Right lobe donors had three bile leaks from the cut surface of the liver; all resolved. Another right lobe donor had prolonged hyperbilirubinemia. Three donors had small bowel obstructions; two required operation. All donors are alive and well. The most common indications for transplant were biliary atresia in children (56%) and hepatitis C in adults (40%); 35.6% of adults had hepatocellular carcinoma. Biliary reconstructions in all children and 44 adults were with a Roux-en-Y hepaticojejunostomy; 15 adults had duct-to-duct anastomoses. The incidence of major vascular complications was 12% in children and 11.8% in adult recipients. Children had three bile leaks (6%) and six (12%) biliary strictures. Adult patients had 14 (23.7%) bile leaks and 4 (6.8%) biliary strictures. Patient and graft survival rates were 87.6% and 81%, respectively, at 1 year and 75.1% and 69.6% at 5 years. In children, patient and graft survival rates were 89.9% and 85.8%, respectively, at 1 year and 80.9% and 78% at 5 years. In adults, patient and graft survival rates were 85.6% and 77%, respectively, at 1 year. CONCLUSION: Living donor liver transplantation has become an important option for our patients and has dramatically changed our approach to patients with liver failure. The donor surgery is safe and can be done with minimal complications. We expect that living donor liver transplants will represent more than 50% of our transplants within 3 years.


Asunto(s)
Trasplante de Hígado , Donantes de Tejidos , Sistema del Grupo Sanguíneo ABO , Adolescente , Adulto , Atresia Biliar/cirugía , Carcinoma Hepatocelular/complicaciones , Niño , Supervivencia de Injerto , Hepatectomía/métodos , Hepatitis C/cirugía , Humanos , Tiempo de Internación , Neoplasias Hepáticas/complicaciones , Trasplante de Hígado/métodos , Persona de Mediana Edad , Complicaciones Posoperatorias
15.
J Biol Chem ; 276(42): 38703-14, 2001 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-11509565

RESUMEN

Ileal reclamation of bile salts, a critical determinant of their enterohepatic circulation, is mediated primarily by the apical sodium-dependent bile acid transporter (ASBT=SLC10A2). We have defined mechanisms involved in the transcriptional regulation of ASBT. The ASBT gene extends over 17 kilobases and contains five introns. Primer extension analysis localized two transcription initiation sites 323 and 255 base pairs upstream of the initiator methionine. Strong promoter activity is imparted by both a 2.7- and 0.2-kilobase 5'-flanking region of ASBT. The promoter activity is cell line specific (Caco-2, not Hep-G2, HeLa-S3, or Madin-Darby canine kidney cells). Four distinct specific binding proteins were identified by gel shift and cross-linking studies using Caco-2 or rat ileal nuclear extracts. Two AP-1 consensus sites were identified in the proximal promoter. DNA binding and promoter activity could be abrogated by mutation of the proximal AP-1 site. Supershift analysis revealed binding of c-Jun and c-Fos to this AP-1 element. Co-expression of c-Jun enhanced promoter activity in Caco-2 cells and activated the promoter in Madin-Darby canine kidney cells. Region and developmental stage-specific expression of ASBT in the rat intestine correlated with the presence of one of these DNA-protein complexes and both c-Fos and c-Jun proteins. A specific AP-1 element regulates transcription of the rat ASBT gene.


Asunto(s)
Proteínas Portadoras/biosíntesis , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Transportadores de Anión Orgánico Sodio-Dependiente , Simportadores , Factor de Transcripción AP-1/metabolismo , Factor de Transcripción AP-1/fisiología , Transcripción Genética , Animales , Secuencia de Bases , Sitios de Unión , Western Blotting , Células CACO-2 , Línea Celular , Núcleo Celular/metabolismo , Clonación Molecular , Exones , Regulación de la Expresión Génica , Biblioteca de Genes , Humanos , Intestino Delgado/metabolismo , Luciferasas/metabolismo , Modelos Genéticos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Mutación , Plásmidos/metabolismo , Regiones Promotoras Genéticas , Unión Proteica , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Conejos , Ratas , Homología de Secuencia de Ácido Nucleico , Transfección , Células Tumorales Cultivadas
16.
J Lipid Res ; 42(9): 1438-43, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11518763

RESUMEN

To study the effect of cholecystectomy on the regulation of classic and alternative bile acid syntheses, gallbladder-intact (n = 20) and cholecystectomized (n = 20) New Zealand White rabbits were fed either chow or chow with 2% cholesterol (3 g/day). After 10 days, bile fistulas were constructed in half of each rabbit group to recover and measure the bile acid pool and biliary bile acid flux. After cholesterol feeding, the bile acid pool size increased from 268 +/- 55 to 444 +/- 77 mg (P < 0.01) with a 2-fold rise in the biliary bile acid flux in intact rabbits but did not expand the bile acid pool (270 +/- 77 vs. 276 +/- 62 mg), nor did the biliary bile acid flux increase in cholecystectomized rabbits. Ileal apical sodium-dependent bile acid transporter protein increased 46% from 93 +/- 6 to 136 +/- 23 units/mg (P < 0.01) in the intact rabbits but did not change in cholecystectomized rabbits (104 +/- 14 vs. 99 +/- 19 units/mg) after cholesterol feeding. Cholesterol 7alpha-hydroxylase activity was inhibited 59% (P < 0.001) while cholesterol 27-hydroxylase activity rose 83% (P < 0.05) after cholesterol feeding in the intact rabbits but neither enzyme activity changed significantly in cholesterol-fed cholecystectomized rabbits. Fecal bile acid outputs reflecting bile acid synthesis increased significantly in the intact but not in the cholecystectomized rabbits fed cholesterol. Removal of the gallbladder prevented expansion of the bile acid pool after cholesterol feeding as seen in intact rabbits because ileal bile acid transport did not increase. As a result, cholesterol 7alpha-hydroxylase was not inhibited.


Asunto(s)
Ácidos y Sales Biliares/biosíntesis , Colecistectomía , Colesterol 7-alfa-Hidroxilasa/antagonistas & inhibidores , Colesterol en la Dieta/administración & dosificación , Vesícula Biliar/fisiología , Hidroxiesteroide Deshidrogenasas , Glicoproteínas de Membrana , Proteínas de Transporte de Membrana , Animales , Ácidos y Sales Biliares/metabolismo , Western Blotting , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Colestanotriol 26-Monooxigenasa , Colesterol/sangre , Colesterol/metabolismo , Colesterol 7-alfa-Hidroxilasa/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Heces/química , Hidroximetilglutaril-CoA Reductasas/metabolismo , Íleon/metabolismo , Hígado/metabolismo , Masculino , Transportadores de Anión Orgánico Sodio-Dependiente , ARN Mensajero/análisis , Conejos , Esteroide Hidroxilasas/metabolismo , Simportadores
17.
J Pediatr Gastroenterol Nutr ; 32(4): 407-17, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11396803

RESUMEN

Intestinal reabsorption of bile salts plays a crucial role in human health and disease. This process is primarily localized to the terminal ileum and is mediated by a 48-kd sodium-dependent bile acid cotransporter (SLC10A2 = ASBT). ASBT is also expressed in renal tubule cells, cholangiocytes, and the gallbladder. Exon skipping leads to a truncated version of ASBT, which sorts to the basolateral surface and mediates efflux of bile salts. Inherited mutation of ASBT leads to congenital diarrhea secondary to bile acid malabsorption. Partial inhibition of ASBT may be useful in the treatment of hypercholesterolemia and intrahepatic cholestasis. During normal development in the rat ileum, ASBT undergoes a biphasic pattern of expression with a prenatal onset, postnatal repression, and reinduction at the time of weaning. The bile acid responsiveness of the ASBT gene is not clear and may be dependent on both the experimental model used and the species being investigated. Future studies of the transcriptional and posttranscriptional regulation of the ASBT gene and analysis of ASBT knockout mice will provide further insight into the biology, physiology, and pathophysiology of intestinal bile acid transport.


Asunto(s)
Ácidos y Sales Biliares/metabolismo , Proteínas Portadoras/fisiología , Absorción Intestinal/fisiología , Transportadores de Anión Orgánico Sodio-Dependiente , Simportadores , Animales , Transporte Biológico/fisiología , Diarrea/etiología , Diarrea/metabolismo , Enfermedades Gastrointestinales/genética , Enfermedades Gastrointestinales/metabolismo , Regulación del Desarrollo de la Expresión Génica , Humanos , Íleon/metabolismo , Ratas , Sodio/metabolismo , Destete
18.
Nat Genet ; 27(4): 375-82, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11279518

RESUMEN

Maturity-onset diabetes of the young type 3 (MODY3) is caused by haploinsufficiency of hepatocyte nuclear factor-1alpha (encoded by TCF1). Tcf1-/- mice have type 2 diabetes, dwarfism, renal Fanconi syndrome, hepatic dysfunction and hypercholestrolemia. Here we explore the molecular basis for the hypercholesterolemia using oligonucleotide microchip expression analysis. We demonstrate that Tcf1-/- mice have a defect in bile acid transport, increased bile acid and liver cholesterol synthesis, and impaired HDL metabolism. Tcf1-/- liver has decreased expression of the basolateral membrane bile acid transporters Slc10a1, Slc21a3 and Slc21a5, leading to impaired portal bile acid uptake and elevated plasma bile acid concentrations. In intestine and kidneys, Tcf1-/- mice lack expression of the ileal bile acid transporter (Slc10a2), resulting in increased fecal and urinary bile acid excretion. The Tcf1 protein (also known as HNF-1alpha) also regulates transcription of the gene (Nr1h4) encoding the farnesoid X receptor-1 (Fxr-1), thereby leading to reduced expression of small heterodimer partner-1 (Shp-1) and repression of Cyp7a1, the rate-limiting enzyme in the classic bile acid biosynthesis pathway. In addition, hepatocyte bile acid storage protein is absent from Tcf1-/- mice. Increased plasma cholesterol of Tcf1-/- mice resides predominantly in large, buoyant, high-density lipoprotein (HDL) particles. This is most likely due to reduced activity of the HDL-catabolic enzyme hepatic lipase (Lipc) and increased expression of HDL-cholesterol esterifying enzyme lecithin:cholesterol acyl transferase (Lcat). Our studies demonstrate that Tcf1, in addition to being an important regulator of insulin secretion, is an essential transcriptional regulator of bile acid and HDL-cholesterol metabolism.


Asunto(s)
Ácidos y Sales Biliares/metabolismo , Colesterol/sangre , Proteínas de Unión al ADN/fisiología , Proteínas Nucleares/fisiología , Animales , Secuencia de Bases , Ácidos y Sales Biliares/biosíntesis , Cartilla de ADN , Factor 1 Inducible por Hipoxia , Subunidad alfa del Factor 1 Inducible por Hipoxia , Íleon/metabolismo , Riñón/metabolismo , Ratones , Ratones Noqueados , Factores de Transcripción/genética , Factores de Transcripción/fisiología
19.
Pediatr Transplant ; 5(6): 410-8, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11765725

RESUMEN

We reviewed the results of 50 magnetic resonance (MR) cholangiograms to evaluate their usefulness in directing clinical management in young patients after liver transplantation (LTx). Thirty-two patients underwent 50 MR cholangiograms on a 1.5-T unit. Studies were performed from 1 week to 16 yr after LTx. Indications included biochemical abnormalities with (n = 19) or without (n = 16) biopsy evidence for chronic rejection, sepsis (n = 14), and intractable ascites (n = 1). Original interpretations were compared to laboratory and ultrasound findings, and clinical outcome. Of 19 studies performed on 14 patients with biopsy evidence of chronic rejection, 16 were abnormal on MR (but only one was abnormal on ultrasound), resulting in corrective surgery (n = 1), re-Tx (n = 1), and endoscopic dilatation (n = 1). Of 16 studies on 16 patients with biochemical abnormalities without evidence of chronic rejection on biopsy, 14 were abnormal on MR (but only five of 13 on ultrasound), leading to corrective surgery (n = 3) and re-listing for Tx (n = 3). Thirteen of 14 studies on six patients with sepsis were abnormal on MR (five of nine were abnormal on ultrasound), identifying surgically correctable strictures (n = 2), and leading to re-Tx (n = 1) and percutaneous biliary drainage procedures (n = 2). The one patient with ascites had a normal study. We advocate usage of MR cholangiography for the detection of biliary complications after LTx, particularly in those patients who present with biochemical abnormalities that are not easily explained by acute cellular rejection or viral infection and in those with biliary sepsis.


Asunto(s)
Enfermedades de las Vías Biliares/diagnóstico , Colangiografía/métodos , Trasplante de Hígado/efectos adversos , Adolescente , Adulto , Conductos Biliares Intrahepáticos/patología , Enfermedades de las Vías Biliares/diagnóstico por imagen , Enfermedades de las Vías Biliares/etiología , Niño , Dilatación Patológica , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Estudios Retrospectivos , Ultrasonografía
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