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1.
Nat Cell Biol ; 3(12): 1129-32, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11781576

RESUMEN

The transmembrane glycoprotein Nicastrin was identified in a complex with the multipass membrane protein Presenilin. Presenilin mediates transmembrane cleavage of single-pass transmembrane proteins with short extracellular domains, including the ligand-activated form of the receptor Notch and beta-amyloid precursor protein (beta-APP). Transmembrane cleavage of Notch is essential for signal transduction, and transmembrane cleavage of beta-APP generates pathogenic amyloid peptides implicated in Alzheimer's disease. Here, we investigate the requirement for Nicastrin in Presenilin-mediated transmembrane cleavage. We show that, in Drosophila, loss of Nicastrin activity blocks the accumulation of Presenilin associated with the apical plasma membrane, abolishes Presenilin-dependent cleavage of the transmembrane domains of Notch and beta-APP, and abrogates Notch signal transduction.


Asunto(s)
Glicoproteínas de Membrana/metabolismo , Proteínas de la Membrana/metabolismo , Secretasas de la Proteína Precursora del Amiloide , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Membrana Celular/metabolismo , Drosophila , Proteínas de Drosophila , Glicoproteínas de Membrana/genética , Mutación/fisiología , Presenilina-1 , Receptores Notch , Transducción de Señal/fisiología
2.
AJNR Am J Neuroradiol ; 28(1): 68-71, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17213426

RESUMEN

BACKGROUND AND PURPOSE: The dynamics of brain-water content associated with hemodialysis in patients with severe azotemia remains obscure. To investigate whether either interstitial or cytotoxic edema is responsible for dialysis disequilibrium syndrome (DDS), we used diffusion-weighted MR imaging (DWI) to measure the apparent diffusion coefficient (ADC), which is sensitive for detecting tissue water dynamics. METHODS: Eight consecutive patients with end stage renal disease (ESRD) and blood urea nitrogen level of more than 100 mg/dL (160.9 +/- 53.1 mg/dL) were recruited. Conventional MR images, DWI, and clinical manifestations were obtained before and after the 1st hemodialysis. The ADC values were determined for regions of normal-appearing gray and white matter and for regions of hyperintensity of white matter on T2-weighted MR imaging. RESULTS: Foci of bright areas of white matter were found in all patients on T2-weighted images. The ADC values of the patients with ESRD, in white matter and gray matter before and after hemodialysis, were greater than those of the healthy controls (P < .005). Regarding the impact of hemodialysis, the ADC of frontal lobe white matter increased significantly after hemodialysis (1.09 +/- 0.11 versus 1.03 +/- 0.11, P = .036). We did not find the specific area of brain edema reported in posterior leukoencephalopathy and the osmotic demyelination syndrome. CONCLUSIONS: These results suggest that severe azotemia in end stage renal disease leads to interstitial brain edema reflected as increased ADC, and the further increased ADC reflects that edema associated with 1st hemodialysis is interstitial rather than cytotoxic in nature.


Asunto(s)
Azotemia/diagnóstico , Edema Encefálico/diagnóstico , Imagen de Difusión por Resonancia Magnética , Diálisis Renal , Uremia/diagnóstico , Adulto , Anciano , Azotemia/terapia , Encéfalo/patología , Diagnóstico Diferencial , Femenino , Glomerulonefritis/complicaciones , Glomerulonefritis/diagnóstico , Glomerulonefritis/terapia , Humanos , Masculino , Persona de Mediana Edad , Nefritis Intersticial/complicaciones , Nefritis Intersticial/diagnóstico , Nefritis Intersticial/terapia , Valores de Referencia , Sensibilidad y Especificidad , Uremia/terapia
3.
Mol Cell Biol ; 13(6): 3734-43, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8497277

RESUMEN

Two types of largest subunit RNA polymerase II (pol II) genes (pol IIA and pol IIB), differing in 3 amino acid substitutions, are encoded in the Trypanosoma brucei (stock 427-60) genome. As a result, the alpha-amanitin-resistant transcription of the procyclic acidic repetitive protein (PARP) and variant surface glycoprotein (VSG) genes was proposed to involve a modified, alpha-amanitin-resistant form of the largest subunit of pol II. Alternatively, pol I could transcribe the PARP and VSG genes. To discriminate between these two models, we deleted the N-terminal domain (about one-third of the polypeptide), which encodes the amino acid substitutions which discriminated the pol IIA and pol IIB genes, at both pol IIB alleles. The pol IIB- trypanosomes still transcribe the PARP genes and the VSG gene promoter region in insect-form trypanosomes by alpha-amanitin-resistant RNA polymerases, while control housekeeping genes are transcribed in an alpha-amanitin-sensitive manner, presumably by pol IIA. We conclude that the alpha-amanitin-resistant transcription of protein coding genes in T. brucei is not mediated by a diverged form of the largest subunit of pol II and that the presence of both the pol IIA and pol IIB genes is not essential for trypanosome viability. This conclusion was further supported by the finding that individual trypanosome variants exhibited allelic heterogeneity for the previously identified amino acid substitutions and that various permutations of the polymorphic amino acids generate at least four different types of largest subunit pol II genes. The expression of the PARP genes and the VSG gene promoter region by alpha-amanitin-resistant RNA polymerases in the pol IIB- trypanosomes provides evidence for transcription of these genes by pol I.


Asunto(s)
ARN Polimerasa II/genética , Trypanosoma brucei brucei/enzimología , Trypanosoma brucei brucei/genética , Amanitinas/farmacología , Animales , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , ADN Protozoario/genética , ADN Protozoario/aislamiento & purificación , Genoma , Sustancias Macromoleculares , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Plásmidos , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Mapeo Restrictivo , Eliminación de Secuencia , Transcripción Genética/efectos de los fármacos , Transformación Genética
4.
Mol Cell Biol ; 11(5): 2467-80, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-1708090

RESUMEN

The expressed variant cell surface glycoprotein (VSG) gene of Trypanosoma brucei is located at the 3' end of a large, telomeric, polycistronic transcription unit or expression site. We show that the region 45 kb upstream of the VSG gene, in the expression site on a 1.5-Mb chromosome, contains at least two promoters that are arranged in tandem, directing the transcription of the expression site. DNA rearrangement events occur specifically, at inactivation of the expression site, and these events delete the most upstream transcribed region and replace it with a large array of simple-sequence DNA, leaving the downstream promoter intact. Because of the placement of simple-sequence DNA, the remaining downstream promoter now becomes structurally identical to previously described VSG promoters. The downstream promoter is repetitive in the genome, since it is present at several different expression sites. Restriction fragment length polymorphism mapping allows grouping of the expression sites into two families, those with and those without an upstream transcription unit, and the DNA rearrangement events convert the expression sites from one type to the other. Deletion of the upstream transcription unit also leads to the loss of several steady-state RNAs. The findings may indicate a role for promoter-associated DNA rearrangement events, and/or interactions between tandemly arranged promoters, in expression site transcriptional control.


Asunto(s)
Reordenamiento Génico , Genes , Regiones Promotoras Genéticas , Trypanosoma brucei brucei/genética , Glicoproteínas Variantes de Superficie de Trypanosoma/genética , Animales , Secuencia de Bases , Northern Blotting , Southern Blotting , Clonación Molecular , ADN/genética , ADN/aislamiento & purificación , Biblioteca de Genes , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , ARN/genética , ARN/aislamiento & purificación , Conejos , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico , Transcripción Genética , Trypanosoma brucei brucei/inmunología
5.
Intern Med J ; 37(2): 130-2, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17229258

RESUMEN

BACKGROUND: Yam bean is a common food in southern Taiwan. However, its seeds are rarely consumed. We describe five patients of yam bean seed poisoning in Taiwan, one of them life-threatening. CLINICAL PRESENTATION: The five patients presented with perioral numbness, nausea and vomiting after eating a same soup made from yam bean seeds. One of them, a 54-year-old woman, had difficulty breathing and lost consciousness. Physical examination showed dilated pupils and coma with no focal neurological signs. The initial blood pressure was normal. Laboratory data showed a severe anion gap metabolic acidosis, with a serum lactate level of 185 mg/dL. An initial diagnosis of cyanide intoxication was considered and she was given sodium nitrite and sodium thiosulfate i.v. Hypotension ensued shortly afterwards and pulmonary artery catheterization showed a decreased cardiac index. Aggressive fluid and inotropic therapy were given and the patient eventually recovered. The other four patients suffered only minor gastrointestinal and neurological symptoms and received supportive treatment. Cyanide levels were negative in all five patients. CONCLUSION: Yam bean seed poisoning can cause acute metabolic acidosis and altered mental status, which could be confused with acute cyanide intoxication from a cyanogenic glycoside-containing plant. To our knowledge, this is the first outbreak of yam bean seed poisoning reported in the English published work.


Asunto(s)
Cianuros/toxicidad , Pachyrhizus/envenenamiento , Intoxicación por Plantas/diagnóstico , Semillas/envenenamiento , Diagnóstico Diferencial , Femenino , Humanos , Persona de Mediana Edad , Síndrome de Dificultad Respiratoria/inducido químicamente , Síndrome de Dificultad Respiratoria/diagnóstico , Inconsciencia/inducido químicamente , Inconsciencia/diagnóstico
6.
Leukemia ; 30(1): 144-53, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26202933

RESUMEN

Although hematopoietic stem cells (HSC) are the best characterized and the most clinically used adult stem cells, efforts are still needed to understand how to best ex vivo expand these cells. Here we present our unexpected finding that OCT4 is involved in the enhancement of cytokine-induced expansion capabilities of human cord blood (CB) HSC. Activation of OCT4 by Oct4-activating compound 1 (OAC1) in CB CD34(+) cells enhanced ex vivo expansion of HSC, as determined by a rigorously defined set of markers for human HSC, and in vivo short-term and long-term repopulating ability in NSG mice. Limiting dilution analysis revealed that OAC1 treatment resulted in 3.5-fold increase in the number of SCID repopulating cells (SRCs) compared with that in day 0 uncultured CD34(+) cells and 6.3-fold increase compared with that in cells treated with control vehicle. Hematopoietic progenitor cells, as assessed by in vitro colony formation, were also enhanced. Furthermore, we showed that OAC1 treatment led to OCT4-mediated upregulation of HOXB4. Consistently, siRNA-mediated knockdown of HOXB4 expression suppressed effects of OAC1 on ex vivo expansion of HSC. Our study has identified the OCT4-HOXB4 axis in ex vivo expansion of human CB HSC.


Asunto(s)
Sangre Fetal/citología , Células Madre Hematopoyéticas/fisiología , Proteínas de Homeodominio/genética , Factor 3 de Transcripción de Unión a Octámeros/fisiología , Factores de Transcripción/genética , Animales , Células Cultivadas , Regulación de la Expresión Génica , Humanos , Ratones
7.
Arch Intern Med ; 146(2): 333-6, 1986 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3947194

RESUMEN

In the present study, we found that at least 4.4% of 1,088 prospectively studied patients developed postoperative hyponatremia (plasma sodium concentration less than 130 mEq/L). Most patients (42%) were normovolemic. Edematous states (21%), hyperglycemia (21%), volume depletion (8%), and renal failure (8%), however, were also common settings of postoperative hyponatremia. Plasma arginine vasopressin was present in all patients in whom it was measured and 94% of the patients were receiving hypotonic fluid at the time of development of hyponatremia. Hyponatremia was not associated with significant neurologic deterioration in the 48 postoperative patients in the present study. In eight patients, however, the positive water balance that resulted in hyponatremia was associated with development of pulmonary vascular congestion. We conclude that hyponatremia commonly occurs following all types of surgical procedures and is due to hypotonic fluid administration in the presence of nonosmotic secretion of arginine vasopressin.


Asunto(s)
Hiponatremia/etiología , Procedimientos Quirúrgicos Operativos/efectos adversos , Adulto , Arginina Vasopresina/sangre , Edema/etiología , Edema/fisiopatología , Humanos , Hiperglucemia/fisiopatología , Hiponatremia/sangre , Hiponatremia/fisiopatología , Enfermedades Renales/complicaciones , Enfermedades Renales/fisiopatología , Concentración Osmolar , Estudios Prospectivos
8.
Int J Dev Biol ; 43(4): 329-34, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10470649

RESUMEN

Mesoderm induction is one of the major events of early vertebrate embryonic patterning. It appears to be controlled by sequential and combinatorial actions of several kinds of peptide growth factors. These include activin, fibroblast growth factor (FGF), and transforming growth factor-beta (TGF-beta), among others. In the present study, the function of platelet-derived growth factor (PDGF) in early Xenopus laevis embryogenesis was investigated. In the animal-cap assay, PDGF caused pre-ectodermal tissue to develop a mesoderm specific morphology (elongation) and to express the mesoderm marker genes, MyoD family and alpha-cardiac actin. In addition, two other genes were expressed -related serum response factor SL1 (a dorsal mesodermal marker) and myosin light chain (MLC2-heart marker). A role for PDGF in normal (in vivo) mesoderm induction is implicated because injection of PDGF receptor alpha antisense RNA into 2-cell embryos erased the animal cap's mesoderm marker expression. Those injected embryos also exhibited morphological abnormalities including incomplete gastrulation, failure of neural fold closing, and abnormal somitogenesis.


Asunto(s)
Factor de Crecimiento Derivado de Plaquetas/fisiología , Xenopus laevis/embriología , Animales , Secuencia de Bases , Tipificación del Cuerpo/efectos de los fármacos , Tipificación del Cuerpo/genética , Tipificación del Cuerpo/fisiología , Cartilla de ADN/genética , Regulación del Desarrollo de la Expresión Génica , Marcadores Genéticos , Hibridación in Situ , Mesodermo/citología , Mesodermo/efectos de los fármacos , Factor de Crecimiento Derivado de Plaquetas/genética , Factor de Crecimiento Derivado de Plaquetas/farmacología , ARN sin Sentido/farmacología , Transducción de Señal , Xenopus laevis/genética
9.
Int J Dev Biol ; 38(3): 421-8, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7848825

RESUMEN

Analysis of the developmental potential of animal quartets (the set of four animal blastomeres isolated from the 8-cell stage Xenopus embryo) provided insight into the manner in which morphogenetic information is distributed along the animal-vegetal axis. Gravity treatments were employed to alter the partitioning plane. Animal quartets isolated from embryos exposed to simulated weightlessness had larger animal blastomeres, and they formed structures such as a groove and a protrusion more often than 1g-control animal quartets. Animal quartets with an unusual non-horizontal third cleavage plane were also found to have a higher frequency of protrusion formation than animal quartets with a typical horizontal cleavage plane. The increase in the frequency seen in simulated weightlessness animal quartets was not due to their increased size. Fusing two animal quartets isolated from hypergravity (3g) exposed embryos (small blastomeres and low incidence of protrusions) did not affect the frequency of protrusion formation. Molecular analyses revealed that a partial induction was associated with the protrusion formation. Transcripts of the dorsal lip specific homeobox gene, goosecoid, and alpha-cardiac actin were detectable by PCR amplification in the animal quartet with a protrusion, and alpha-cardiac actin mRNA was found by whole-mount in situ hybridization to be localized in the protrusion. Taken together, all these results are consistent with the notion that both animal and vegetal information is necessary for normal development and the partitioning of morphogenetic information into animal quartets results in gravity-dependent differential morphogenesis and gene regulation.


Asunto(s)
Blastómeros/fisiología , Inducción Embrionaria , Proteínas de Homeodominio , Proteínas Represoras , Factores de Transcripción , Actinas/análisis , Activinas , Animales , Secuencia de Bases , Blastómeros/química , Técnicas de Cultivo , Proteínas de Unión al ADN/análisis , Ectodermo/fisiología , Regulación del Desarrollo de la Expresión Génica , Proteína Goosecoide , Gravitación , Inhibinas/farmacología , Datos de Secuencia Molecular , Morfogénesis/efectos de los fármacos , ARN Mensajero/análisis , Simulación de Ingravidez , Xenopus laevis
10.
Clin Pharmacol Ther ; 59(4): 411-7, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8612385

RESUMEN

BACKGROUND: The polymorphic metabolism of debrisoquin and sparteine by cytochrome P450IID6 (CYP2D6) is genetically determined. Determination of the CYP2D6 metabolic phenotype with conventional urine analytic methods is not feasible in anuric patients with renal failure. The possibility of using salivary analysis, with dextromethorphan as a probe drug, to determine the CYP2D6 metabolic phenotype in patients with renal failure was evaluated. METHODS AND RESULTS: One hundred four Chinese patients with renal failure were recruited. All 104 patients were receiving hemodialysis. Saliva was collected before and at 3 hours after each patient took a capsule of dextromethorphan hydrobromide (30 mg). Four patients were excluded because of insufficient samples of saliva. The distribution of logarithms of the metabolic ratios (log[MR]) in the 100 patients appeared to be normal. Administration of quinidine sulfate (200 mg twice daily) to nine of the patients significantly and markedly increased the dextromethorphan metabolic ratios. The metabolic ratios of nine patients pretreated with quinidine were higher than any of the 100 patients with renal failure who did not receive quinidine pretreatment. A metabolic ratio of 33 separated these two groups. Genomic deoxyribonucleic acid was extracted from whole blood in a subset of patients. Polymerase chain reaction (PCR)-based methods were used to detect the CYP2D6 and B mutant genes. Mutant B alleles (which are common in white poor metabolizers) of CYP2D6 genes were not detected in any of the 47 subjects tested. A PCR-based test of cytosine (C188) to thymine (T188) polymorphism at 188 base pairs in exon 1 of CYP2D6 genes was performed in 61 patients. Subjects who were homozygous for C188 had significantly (p = 0.0067) lower log[MR] values than those who were homozygous for T188. CONCLUSIONS: Determination of dextromethorphan metabolic ratios in saliva is feasible in patients with renal failure requiring hemodialysis. All subjects in this study appeared to be "extensive metabolizer" phenotype for CYP2D6, and no poor metabolizer was identified. From the results with quinidine pretreatment, a metabolic ratio of 33 is suggested to be a tentative antimode for identification of poor metabolizers in patients with renal failure.


Asunto(s)
Dextrometorfano/farmacocinética , Fallo Renal Crónico/metabolismo , Diálisis Renal , Saliva/metabolismo , Adulto , Antiarrítmicos/farmacología , China/etnología , Citocromo P-450 CYP2D6 , Sistema Enzimático del Citocromo P-450 , Femenino , Genotipo , Humanos , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Oxigenasas de Función Mixta , Fenotipo , Quinidina/farmacología , Taiwán
11.
Am J Med ; 83(5): 905-8, 1987 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3674097

RESUMEN

Assessment of the status of extracellular fluid volume is important in evaluating the cause and selecting appropriate therapy for hyponatremic disorders. Since the sensitivity and specificity of clinical assessment of extracellular fluid volume status in hyponatremic states remain unknown, 58 non-edematous patients with serum sodium less than 130 meq/liter were prospectively evaluated. Patients were judged to be either normovolemic (no response of serum sodium to saline infusion) or hypovolemic (saline infusion significantly corrected hyponatremia). Hypovolemic patients had significantly higher plasma renin activity (5.0 +/- 1.5 versus 2.5 +/- 0.5 ng/ml per three hours, p less than 0.05) and norepinephrine (1,054 +/- 252 versus 519 +/- 55 pg/ml, p less than 0.05) concentrations than did normovolemic patients. Clinical assessment correctly identified only 47 percent of hypovolemic patients and 48 percent of normovolemic patients. Thus, clinical assessment was of limited sensitivity and specificity in identifying extracellular fluid volume status in these hyponatremic patients. However, the concentration of sodium in a spot urine sample clearly separated hypovolemic (mean UNa = 18.4 +/- 3.1 meq/liter) from normovolemic (mean UNa = 72 +/- 3.7 meq/liter, p less than 0.001) hyponatremic patients.


Asunto(s)
Espacio Extracelular/análisis , Hiponatremia/diagnóstico , Fluidoterapia , Humanos , Hiponatremia/terapia , Estudios Prospectivos , Sodio/sangre , Cloruro de Sodio
12.
Am J Kidney Dis ; 37(2): 418-22, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11157385

RESUMEN

Acute oxalate nephropathy associated with ingestion of star fruit (carambola) has not been reported before. We report the first two cases. These patients developed nausea, vomiting, abdominal pain, and backache within hours of ingesting large quantities of sour carambola juice; then acute renal failure followed. Both patients needed hemodialysis for oliguric acute renal failure, and pathologic examinations showed typical changes of acute oxalate nephropathy. The renal function recovered 4 weeks later without specific treatment. Sour carambola juice is a popular beverage in Taiwan. The popularity of star fruit juice is not compatible with the rare discovery of star fruit-associated acute oxalate nephropathy. Commercial carambola juice usually is prepared by pickling and dilution processes that reduce oxalate content markedly, whereas pure fresh juice or mild diluted postpickled juice for traditional remedies, as used in our cases, contain high quantities of oxalate. An empty stomach and dehydrated state may pose an additional risk for development of renal injury. To avoid acute oxalate nephropathy, pure sour carambola juice or mild diluted postpickled juice should not be consumed in large amounts, especially on an empty stomach or in a dehydrated state.


Asunto(s)
Lesión Renal Aguda/inducido químicamente , Frutas/efectos adversos , Oxalatos/efectos adversos , Adulto , Anciano , Cromatografía Líquida de Alta Presión , Frutas/química , Humanos , Oxalatos/análisis
13.
Am J Kidney Dis ; 38(4): E17, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11576904

RESUMEN

Rhabdomyolysis resulting from mushroom poisoning previously has been unreported in the literature. We present an outbreak of Russula subnigricans poisoning with rhabdomyolysis. The most severely ill patient presented with rhabdomyolysis, severe electrolyte disturbance (hyperkalemia, hypocalcemia), respiratory failure, acute renal failure, pulmonary edema, ventricular tachycardia, and circulatory shock. Mycotoxin may be the cause of rhabdomyolysis. In areas where mushroom gathering is common, mushroom poisoning should be included in the differential diagnosis of rhabdomyolysis.


Asunto(s)
Intoxicación por Setas/complicaciones , Rabdomiólisis/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia Renal/etiología
14.
Am J Kidney Dis ; 38(4): 876-80, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11576894

RESUMEN

In this study, we intend to establish a connection between star fruit and acute oxalate nephropathy and also investigate predisposing factors for its development. Male Sprague-Dawley rats of 180 to 200 g were assigned to four groups; namely, control, experimental, fasting, and water-deprivation groups. The former two groups were subjected to both fasting and water deprivation, whereas the latter two groups were subjected to either fasting or water deprivation, respectively. Except for tap water for controls, the remaining groups were administered 4 mL/100 g of body weight of sour star fruit juice with an oxalate concentration of 2.46 g/dL. After these procedures, serial measurement of serum creatinine levels and kidney pathological examination were performed. Peak serum creatinine levels in the control, experimental, fasting, and water-deprivation groups were 0.50 +/- 0.04, 1.46 +/- 0.26, 0.68 +/- 0.20, and 0.52 +/- 0.08 mg/dL, respectively. The experimental group had a greater peak serum creatinine level (P < 0.05). Mean serum creatinine levels of the experimental group days 0, 1, 2, 3, 4, and 5 were 0.43 +/- 0.03, 1.11 +/- 0.18, 1.31 +/- 0.27, 1.16 +/- 0.28, 0.8 +/- 0.26, and 0.82 +/- 0.28 mg/dL, respectively. Mean serum creatinine levels days 1 to 3 were greater than that day 0 (P < 0.05). Pearson's correlation analysis of peak serum creatinine level and kidney weight for the experimental group showed a significant correlation (R = 0.75; P < 0.05; n = 9). In addition to typical changes of oxalate nephropathy, kidney pathological examination showed many refractile oxalate crystals with all rainbow colors under polarized light microscopy in the experimental group. In conclusion, sour star fruit with abundant oxalate contents could cause acute oxalate nephropathy in rats under the conditions of fasting and water deprivation.


Asunto(s)
Lesión Renal Aguda/inducido químicamente , Frutas/efectos adversos , Oxalatos/efectos adversos , Lesión Renal Aguda/sangre , Animales , Oxalato de Calcio/química , Creatinina/sangre , Cristalización , Ingestión de Líquidos , Ayuno/sangre , Frutas/química , Riñón/efectos de los fármacos , Riñón/patología , Masculino , Tamaño de los Órganos , Oxalatos/análisis , Ratas , Ratas Sprague-Dawley
15.
Mol Cell Endocrinol ; 169(1-2): 43-7, 2000 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-11155953

RESUMEN

The establishment of a long-term preservation system for mammalian oocytes is important for the development of both biological and medical sciences. A number of efforts have been made to develop this system. In human reproductive medicine, the development of an oocyte cryopreservation system can improve the efficacy of the current assisted reproductive technology (ART) for infertile patients with severe reproductive disorders. In this article, the technical development of cryopreservation programs for human oocytes and its biological background were reviewed. Clinical outcome after the use of this technology was further introduced.


Asunto(s)
Criopreservación/métodos , Oocitos/citología , Técnicas de Cultivo de Célula/métodos , Criopreservación/historia , Criopreservación/normas , Europa (Continente) , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Infertilidad Femenina , Embarazo , Técnicas Reproductivas
16.
J Biochem ; 98(6): 1723-6, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3937842

RESUMEN

The DNA-cleavage specificity of ascorbate in the presence of copper ion is analyzed with end-labeled pBR322 DNA fragments. The nonenzymatic reaction of Cu(II)/ascorbate and DNA shows certain degrees of cleavage preference toward purine-containing short segments in the labeled DNA under mild conditions (at 0 degrees C and 10 min). The segments of pyrimidine clusters are least susceptible to cleavage. The DNA scission cannot be detected in the absence of metal ions, and is greatly diminished in the presence of EDTA and metal-chelating peptide. It is more specific than the nuclease-like scission activity induced by cuprous-phenanthroline complex. This scission activity in relation to the antiviral and antitumor activities of vitamin C reported in the literature deserves a crucial consideration.


Asunto(s)
Ácido Ascórbico/metabolismo , Cobre/metabolismo , ADN Bacteriano/metabolismo , Secuencia de Bases , Quelantes/farmacología , Ácido Edético/farmacología , Oligopéptidos/farmacología , Oxidación-Reducción , Fenantrolinas/metabolismo , Plásmidos
17.
Mol Cells ; 9(5): 497-503, 1999 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-10597038

RESUMEN

The primary patterning event in early vertebrate development is the formation of mesoderm and subsequent induction of the neural tube by the mesoderm. Some of the transforming growth factor (TGF)-beta family (Activin, Vg1) and the fibroblast growth factor (FGF) family molecules have been implicated for their roles in mesoderm induction. Here we show first the evidence that neuregulin, an epidermal growth factor (EGF)-like growth factor known for its role in neural and muscle differentiation, participates in mesoderm induction. Neuregulin could induce the ectopic expression of mesoderm specific gene Xbra in animal cap explants reared to the midgastrula stage, when animal caps dissected from late blastula were cultured with Neuregulin at a low concentration (10 ng/ml). In situ hybridization study showed that alpha-cardiac actin was expressed in animal caps that were treated with Neuregulin overnight. Skeletal and cardiac muscle specific genes such as MyoD family genes (myoD, MRF4, myf5) and SL1 as well as NCAM, a pan neural marker, were also ectopically expressed by treatment with Neuregulin. However, the expression of NCAM is presumed to be a secondary result of the initial mesoderm induction by Neuregulin. The temporal expression pattern of neuregulin during the early developmental stages was analyzed by RT-PCR in order to determine if neuregulin is expressed at the time of mesoderm induction. It has been found that the neuregulin transcript was already detected from the 16-cell stage (stage 5) and continued to be expressed till the tailbud stage (stage 25), the latest embryonic stage analyzed in this study. Considering that the mesoderm is induced at early blastula before the start of zygotic transcription, maternal neuregulin is expressed at the right time to participate in mesoderm induction. These data strongly suggest that neuregulin plays an important role in mesoderm induction.


Asunto(s)
Ectodermo/metabolismo , Regulación del Desarrollo de la Expresión Génica , Mesodermo/metabolismo , Neurregulinas/fisiología , Actinas/biosíntesis , Actinas/genética , Animales , Blastocisto/metabolismo , Embrión no Mamífero/metabolismo , Femenino , Gástrula/metabolismo , Hibridación in Situ , Masculino , Morfogénesis/genética , Proteínas Musculares/biosíntesis , Proteínas Musculares/genética , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/genética , Neurregulinas/biosíntesis , Neurregulinas/genética , Especificidad de Órganos , Proteínas de Dominio T Box/biosíntesis , Proteínas de Dominio T Box/genética , Proteínas de Xenopus , Xenopus laevis/embriología
18.
Eur J Pharmacol ; 408(2): 99-106, 2000 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-11080515

RESUMEN

The effect of betulinic acid, an anti-tumor and apoptosis-inducing natural product, on intracellular-free levels of Ca(2+) ([Ca(2+)](i)) in Madin Darby canine kidney (MDCK) cells was examined by using fura-2 as a Ca(2+) dye. Betulinic acid caused significant increases in [Ca(2+)](i) concentration dependently between 25 and 500 nM with an EC(50) of 100 nM. The [Ca(2+)](i) signal was composed of an initial gradual rise and a plateau. The response was decreased by removal of extracellular Ca(2+) by 45+/-10%. In Ca(2+)-free medium, pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) abolished 250 microM betulinic acid-induced [Ca(2+)](i) increases. Conversely, pretreatment with betulinic acid only partly inhibited thapsigargin-induced [Ca(2+)](i) increases. Addition of 3 mM Ca(2+) induced a [Ca(2+)](i) increase after pretreatment with 250 nM betulinic acid in Ca(2+)-free medium for 5 min. This [Ca(2+)](i) increase was not altered by the addition of 20 microM SKF96365 and 10 microM econazole. Inhibiting inositol 1,4,5-trisphosphate formation with the phospholipase C inhibitor U73122 (2 microM) abolished 250 nM betulinic acid-induced Ca(2+) release. Pretreatment with 10 microM La(3+) inhibited 250 nM betulinic acid-induced [Ca(2+)](i) increases by 85+/-3%; whereas 10 microM of verapamil, nifedipine and diltiazem had no effect. In Ca(2+) medium, pretreatment with 2.5 nM betulinic aid for 260 s potentiated 10 microM ATP and 1 microM thapsigargin-induced [Ca(2+)](i) increases by 33+/-3% and 45+/-3%, respectively. Trypan blue exclusion revealed that acute exposure of 250 nM betulinic acid for 2-30 min decreased cell viability by 6+/-2%, which could be prevented by pretreatment with 2 microM U731222. Together, the results suggest that betulinic acid induced significant [Ca(2+)](i) increases in MDCK cells in a concentration-dependent manner, and also induced mild cell death. The [Ca(2+)](i) signal was contributed by an inositol 1,4, 5-trisphosphate-dependent release of intracellular Ca(2+) from thapsigargin-sensitive stores, and by inducing Ca(2+) entry from extracellular medium in a La(3+)-sensitive manner.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Calcio/metabolismo , Riñón/efectos de los fármacos , Triterpenos/farmacología , Adenosina Trifosfato/farmacología , Animales , Carcinógenos/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Perros , Colorantes Fluorescentes/metabolismo , Fura-2/metabolismo , Riñón/citología , Riñón/metabolismo , Triterpenos Pentacíclicos , Tapsigargina/farmacología , Ácido Betulínico
19.
Int J Tuberc Lung Dis ; 8(1): 92-7, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14974751

RESUMEN

OBJECTIVE: To elucidate the clinical manifestations and risk factors of the mortality rate in uraemic patients with tuberculosis (TB) infection. DESIGN: We retrospectively analysed 62 patients with uraemia and active tuberculosis who were admitted to our hospital from 1990 through 2000. The patients were followed up for 2 years after discharge or until death. RESULTS: There were 43 men and 19 women, with a mean age of 63 +/- 13 years. Extra-pulmonary TB was noted in 51.6%. The peritoneum and pleura were the two most common organs involved. Fever of unknown origin was the most common manifestation (77.4%). The corrected serum Ca2+ level of the patients was >10.5 mg/dl in 46.8%. C-reactive protein >6 mg/dl and leukocytosis (white blood cell count >10,000/mm3) at presentation were noted in more than half of the patients. A reversed serum albumin/globulin ratio and leukocytosis were found to be associated with mortality rate. CONCLUSION: More than half of the TB infections in patients with end-stage renal disease presented with extra-pulmonary involvement. Fever of unknown origin, reversed serum albumin/globulin ratio, and unexplained hypercalcaemia in maintenance dialysis patients suggested the possibility of tuberculosis.


Asunto(s)
Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/epidemiología , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Distribución por Edad , Anciano , Antituberculosos/administración & dosificación , Terapia Combinada , Comorbilidad , Femenino , Humanos , Fallo Renal Crónico/terapia , Modelos Logísticos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Probabilidad , Pronóstico , Diálisis Renal , Estudios Retrospectivos , Medición de Riesgo , Muestreo , Índice de Severidad de la Enfermedad , Distribución por Sexo , Análisis de Supervivencia , Taiwán/epidemiología , Resultado del Tratamiento , Tuberculosis/terapia
20.
Fertil Steril ; 73(5): 978-83, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10785224

RESUMEN

OBJECTIVE: To improve the efficacy of an IVF-ET program for unstimulated patients with polycystic ovary syndrome (PCOS) with the use of culture for oocyte maturation. DESIGN: Prospective studies with the comparison of different ET procedures from March 1995 through February 1998. SETTING: University-affiliated hospital. PATIENT(S): Ninety-four cycles in 64 consenting patients with PCOS. INTERVENTION(S): Immature oocytes were retrieved from unstimulated patients with PCOS and subsequently cultured and fertilized in vitro. Zygote intrafallopian transfer (ZIFT), uterine ET, or a combined approach of ZIFT + uterine ET was subsequently performed. MAIN OUTCOME MEASURE(S): Laboratory and clinical data. RESULT(S): Among 1, 280 immature oocytes (13.6 +/- 7.5 oocytes per patient) retrieved, 89% (1,139) were morphologically normal, and 62.2% (708/1,139) of the normal oocytes matured in vitro after culture for 48 hours. When intracytoplasmic sperm injection was performed, 68% (481/708) developed to the normal pronuclear stage, and 88.1% of the embryos cocultured with Vero cells (266/302) cleaved. Eighty-five ET cycles were conducted and pregnancy was established in 23 cycles (27.1%), which consisted of 8 after uterine ET and 15 after a combined approach. Seventeen patients delivered 20 normal infants. CONCLUSION(S): The IVF-ET method using no ovarian stimulation followed by in vitro maturation culture can be a feasible assisted reproductive technology for treatment of PCOS with various complications.


Asunto(s)
Transferencia de Embrión , Fertilización In Vitro , Síndrome del Ovario Poliquístico , Resultado del Embarazo , Adulto , Animales , Chlorocebus aethiops , Medios de Cultivo , Femenino , Humanos , Oocitos/crecimiento & desarrollo , Embarazo , Células Vero
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