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1.
Ann Oncol ; 19(10): 1720-6, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18550577

RESUMEN

BACKGROUND: To demonstrate the noninferiority of capecitabine plus oxaliplatin (XELOX) versus 5-fluorouracil/folinic acid and oxaliplatin (FOLFOX-4) as second-line therapy in patients with metastatic colorectal cancer after prior irinotecan-based chemotherapy. PATIENTS AND METHODS: A total of 627 patients were randomly assigned to receive XELOX (n = 313) or FOLFOX-4 (n = 314) following disease progression/recurrence or intolerance to irinotecan-based chemotherapy. The primary end point was progression-free survival (PFS). RESULTS: PFS for XELOX was noninferior to FOLFOX-4 [hazard ratio (HR) = 0.97; 95% confidence interval (CI) 0.83-1.14] in the intention-to-treat (ITT) population. Median PFS was 4.7 months with XELOX versus 4.8 months with FOLFOX-4. The robustness of the primary analysis was supported by multivariate and subgroup analyses. Median overall survival in the ITT population was 11.9 months with XELOX versus 12.5 months with FOLFOX-4 (HR = 1.02; 95% CI 0.86-1.21). Treatment-related grade 3/4 adverse events occurred in 50% of XELOX- and 65% of FOLFOX-4-treated patients. Whereas grade 3/4 neutropenia (35% versus 5% with XELOX) and febrile neutropenia (4% versus < 1%) were more common with FOLFOX-4, grade 3/4 diarrhea (19% versus 5% with FOLFOX-4) and grade 3 hand-foot syndrome (4% versus < 1%) were more common with XELOX. CONCLUSION: XELOX is noninferior to FOLFOX-4 when administered as second-line treatment in patients with metastatic colorectal cancer.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Camptotecina/análogos & derivados , Camptotecina/farmacología , Capecitabina , Neoplasias Colorrectales/patología , Desoxicitidina/administración & dosificación , Desoxicitidina/efectos adversos , Desoxicitidina/análogos & derivados , Progresión de la Enfermedad , Resistencia a Antineoplásicos , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Fluorouracilo/análogos & derivados , Humanos , Irinotecán , Leucovorina/administración & dosificación , Leucovorina/efectos adversos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Compuestos Organoplatinos/administración & dosificación , Compuestos Organoplatinos/efectos adversos , Oxaliplatino
2.
Mol Biol Cell ; 12(12): 3864-74, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11739786

RESUMEN

Chicken erythroid ankyrin undergoes a fairly rapid cycle of cytoskeletal association, dissociation, and turnover. In addition, the cytoskeletal association of ankyrin is regulated by phosphorylation. Treatment of erythroid cells with serine and threonine phosphatase inhibitors stimulated the hyperphosphorylation of the 225- and 205-kDa ankyrin isoforms, and dissociated the bulk of these isoforms from cytoskeletal spectrin. In vitro binding studies have shown that this dissociation of ankyrin from spectrin in vivo can be attributed to a reduced ability of hyperphosphorylated ankyrin to bind spectrin. Interestingly, a significant fraction of detergent insoluble ankyrin accumulates in a spectrin-independent pool. At least some of this spectrin-independent pool of ankyrin is complexed with the AE1 anion exchanger, and the solubility properties of this pool are also regulated by phosphorylation. Treatment of cells with serine and threonine phosphatase inhibitors had no effect on ankyrin/AE1 complex formation. However, these inhibitors were sufficient to shift ankyrin/AE1 complexes from the detergent insoluble to the soluble pool. These analyses, which are the first to document the in vivo consequences of ankyrin phosphorylation, indicate that erythroid ankyrin-containing complexes can undergo dynamic rearrangements in response to changes in phosphorylation.


Asunto(s)
Ancirinas/metabolismo , Células Precursoras Eritroides/metabolismo , Animales , Proteína 1 de Intercambio de Anión de Eritrocito/metabolismo , Núcleo Celular/metabolismo , Embrión de Pollo , Inhibidores Enzimáticos/farmacología , Toxinas Marinas , Ácido Ocadaico/farmacología , Oxazoles/farmacología , Mapeo Peptídico , Fosfoproteínas Fosfatasas/antagonistas & inhibidores , Fosfoproteínas Fosfatasas/metabolismo , Fosforilación/efectos de los fármacos , Solubilidad/efectos de los fármacos , Espectrina/metabolismo
3.
J Anat ; 198(Pt 2): 229-38, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11273047

RESUMEN

The expression of carbonic anhydrase in the chorioallantoic membrane (CAM) of the chick embryo was investigated by means of the histochemical localisation of the enzyme catalytic sites and the immunohistochemical identification of its isoenzymatic forms. The results show that carbonic anhydrase is developmentally expressed in a subset of cells both in the ectodermal and the endodermal epithelium. The distribution patterns from both methodological approaches indicated that carbonic anhydrase is a marker of the villus cavity cells and the mitochondria-rich cells in the ectodermal and the endodermal epithelium, respectively. Such a cell-specific pattern of the enzyme expression provides a further contribution to characterising the heterogeneous cell population of the chick CAM and supports specific functional involvement for the distinct cell types in CAM-mediated processes, such as calcium transport, maintenance of acid-base balance and water and electrolyte reabsorption, during chick embryogenesis.


Asunto(s)
Alantoides/enzimología , Anhidrasas Carbónicas/análisis , Embrión de Pollo/enzimología , Embrión de Pollo/crecimiento & desarrollo , Corion/enzimología , Animales , Western Blotting/métodos , Electroforesis en Gel de Poliacrilamida , Histocitoquímica/métodos , Inmunohistoquímica/métodos , Morfogénesis/fisiología
4.
N Engl J Med ; 343(13): 905-14, 2000 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-11006366

RESUMEN

BACKGROUND: The combination of fluorouracil and leucovorin has until recently been standard therapy for metastatic colorectal cancer. Irinotecan prolongs survival in patients with colorectal cancer that is refractory to treatment with fluorouracil and leucovorin. In a multicenter trial, we compared a combination of irinotecan, fluorouracil and leucovorin with bolus doses of fluorouracil and leucovorin as first-line therapy for metastatic colorectal cancer. A third group of patients received irinotecan alone. METHODS: Patients were randomly assigned to receive irinotecan (125 mg per square meter of body-surface area intravenously), fluorouracil (500 mg per square meter as an intravenous bolus), and leucovorin (20 mg per square meter as an intravenous bolus) weekly for four weeks every six weeks; fluorouracil (425 mg per square meter as an intravenous bolus) and leucovorin (20 mg per square meter as an intravenous bolus) daily for five consecutive days every four weeks; or irinotecan alone (125 mg per square meter intravenously) weekly for four weeks every six weeks. End points included progression-free survival and overall survival. RESULTS: Of 683 patients, 231 were assigned to receive irinotecan, fluorouracil, and leucovorin; 226 to receive fluorouracil and leucovorin; and 226 to receive irinotecan alone. In an intention-to-treat analysis, as compared with treatment with fluorouracil and leucovorin, treatment with irinotecan, fluorouracil, and leucovorin resulted in significantly longer progression-free survival (median, 7.0 vs. 4.3 months; P=0.004), a higher rate of confirmed response (39 percent vs. 21 percent, P<0.001), and longer overall survival (median, 14.8 vs. 12.6 months; P=0.04). Results for irinotecan alone were similar to those for fluorouracil and leucovorin. Grade 3 (severe) diarrhea was more common during treatment with irinotecan, fluorouracil, and leucovorin than during treatment with fluorouracil and leucovorin, but the incidence of grade 4 (life-threatening) diarrhea was similar in the two groups (<8 percent). Grade 3 or 4 mucositis, grade 4 neutropenia, and neutropenic fever were less frequent during treatment with irinotecan, fluorouracil, and leucovorin. Adding irinotecan to the regimen of fluorouracil and leucovorin did not compromise the quality of life. CONCLUSIONS: Weekly treatment with irinotecan plus fluorouracil and leucovorin is superior to a widely used regimen of fluorouracil and leucovorin for metastatic colorectal cancer in terms of progression-free survival and overall survival.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Camptotecina/análogos & derivados , Camptotecina/administración & dosificación , Neoplasias Colorrectales/tratamiento farmacológico , Fluorouracilo/administración & dosificación , Leucovorina/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Camptotecina/efectos adversos , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Diarrea/inducido químicamente , Supervivencia sin Enfermedad , Femenino , Humanos , Irinotecán , Masculino , Persona de Mediana Edad , Mucosa Bucal , Metástasis de la Neoplasia , Neutropenia/inducido químicamente , Modelos de Riesgos Proporcionales , Calidad de Vida , Estomatitis/inducido químicamente , Análisis de Supervivencia
5.
J Cell Biol ; 147(6): 1237-48, 1999 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-10601337

RESUMEN

The variant chicken kidney AE1 anion exchangers differ only at the NH(2) terminus of their cytoplasmic domains. Transfection studies have indicated that the variant chicken AE1-4 anion exchanger accumulates in the basolateral membrane of polarized MDCK kidney epithelial cells, while the AE1-3 variant, which lacks the NH(2)-terminal 63 amino acids of AE1-4, primarily accumulates in the apical membrane. Mutagenesis studies have shown that the basolateral accumulation of AE1-4 is dependent upon two tyrosine residues at amino acids 44 and 47 of the polypeptide. Interestingly, either of these tyrosines is sufficient to direct efficient basolateral sorting of AE1-4. However, in the absence of both tyrosine residues, AE1-4 accumulates in the apical membrane of MDCK cells. Pulse-chase studies have shown that after delivery to the cell surface, newly synthesized AE1-4 is recycled to the Golgi where it acquires additional N-linked sugar modifications. This Golgi recycling activity is dependent upon the same cytoplasmic tyrosine residues that are required for the basolateral sorting of this variant transporter. Furthermore, mutants of AE1-4 that are defective in Golgi recycling are unable to associate with the detergent insoluble actin cytoskeleton and are rapidly turned over. These studies, which represent the first description of tyrosine-dependent cytoplasmic sorting signal for a type III membrane protein, have suggested a critical role for the actin cytoskeleton in regulating AE1 anion exchanger localization and stability in this epithelial cell type.


Asunto(s)
Antiportadores/química , Antiportadores/metabolismo , Polaridad Celular , Variación Genética/genética , Aparato de Golgi/metabolismo , Túbulos Renales Colectores/citología , Actinas/metabolismo , Secuencia de Aminoácidos , Animales , Antiportadores/biosíntesis , Antiportadores/genética , Transporte Biológico , Línea Celular , Membrana Celular/metabolismo , Embrión de Pollo , Citoesqueleto/química , Citoesqueleto/metabolismo , Detergentes/farmacología , Perros , Células Epiteliales/citología , Células Epiteliales/metabolismo , Glicosilación , Túbulos Renales Colectores/metabolismo , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Peso Molecular , Mutación/genética , Solubilidad/efectos de los fármacos , Tirosina/genética , Tirosina/metabolismo
6.
Cancer ; 85(4): 786-95, 1999 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-10091755

RESUMEN

BACKGROUND: This multicenter, Phase II trial was performed to evaluate the antitumor activity and toxicity of irinotecan (CPT-11) in patients with metastatic colorectal carcinoma that had recurred or progressed after 5-fluorouracil (5-FU)-based chemotherapy. METHODS: CPT-11 was given as a 90-minute intravenous infusion in repeated 6-week (42-day) courses comprising weekly treatment for 4 consecutive weeks followed by a 2-week rest. Tumor measurements were obtained after every second course of therapy. Toxicity was assessed weekly using the National Cancer Institute Common Toxicity Criteria. RESULTS: A total of 166 patients were entered into the trial. The first 64 patients received a starting dose of 125 mg/m2. An additional 102 patients were enrolled at a starting dose of 100 mg/m2 to determine whether a reduction in the starting dose would result in lower toxicity without sacrificing efficacy. Objective responses to CPT-11 were observed in 18 patients (1 complete response and 17 partial responses) (response rate [RR] = 10.8%; 95% confidence interval [CI], 6.1-15.6%). An additional 67 patients (40.4%) had stable disease as their best response. At the 125 mg/m2 starting dose, the RR was 14.1% (9 of 64 patients; 95% CI, 5.5-22.6%). Among patients given a starting dose of 100 mg/m2, the RR was 8.8% (9 of 102 patients; 95% CI, 3.3-14.3%). The overall median survival was 9.9 months (range, 0.3-36.8 months). The most frequently observed Grade 3/4 toxicities were gastrointestinal events (i.e., diarrhea [27.1%], nausea [15.1%], emesis [9.6%], abdominal cramping [22.2%], and neutropenia [19.9%]). There were no significant differences in the frequencies of Grade 3/4 toxicities between the 125 mg/m2 and 100 mg/m2 starting dose levels except for Grade 3/4 emesis (21.9% vs. 2%; P < 0.001). Patients age > or = 65 years were twice as likely (38.6% vs. 18.8%; P < 0.008) to develop Grade 3/4 diarrhea compared with younger patients when all courses of therapy were evaluated. However, older age did not significantly predict for a higher incidence of first-course diarrhea (25.0% vs. 14.7%; P = 0.106). CONCLUSIONS: CPT-11 can induce tumor regression in patients with metastatic colorectal carcinoma that has progressed during or shortly after 5-FU-based chemotherapy. Gastrointestinal events and neutropenia were the most common serious toxicities. Given the trend toward a higher response rate without substantially greater toxicity, 125 mg/m2 has been selected as the preferred starting dose for further studies. Careful attention to appropriate CPT-11 dose modification and early intervention with loperamide may be especially important in elderly patients.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Camptotecina/análogos & derivados , Neoplasias Colorrectales/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Antimetabolitos Antineoplásicos/administración & dosificación , Antineoplásicos Fitogénicos/efectos adversos , Camptotecina/administración & dosificación , Camptotecina/efectos adversos , Antígeno Carcinoembrionario/sangre , Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/patología , Diarrea/inducido químicamente , Progresión de la Enfermedad , Esquema de Medicación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Infusiones Intravenosas , Irinotecán , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Neutropenia/inducido químicamente , Vómitos/inducido químicamente
7.
Mol Biol Cell ; 10(2): 455-69, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9950688

RESUMEN

Chicken erythroid AE1 anion exchangers receive endoglycosidase F (endo F)-sensitive sugar modifications in their initial transit through the secretory pathway. After delivery to the plasma membrane, anion exchangers are internalized and recycled to the Golgi where they acquire additional N-linked modifications that are resistant to endo F. During recycling, some of the anion exchangers become detergent insoluble. The acquisition of detergent insolubility correlates with the association of the anion exchanger with cytoskeletal ankyrin. Reagents that inhibit different steps in the endocytic pathway, including 0.4 M sucrose, ammonium chloride, and brefeldin A, block the acquisition of endo F-resistant sugars and the acquisition of detergent insolubility by newly synthesized anion exchangers. The inhibitory effects of ammonium chloride on anion exchanger processing are rapidly reversible. Furthermore, AE1 anion exchangers become detergent insoluble more rapidly than they acquire endo F-resistant modifications in cells recovering from an ammonium chloride block. This suggests that the cytoskeletal association of the recycling anion exchangers occurs after release from the compartment where they accumulate due to ammonium chloride treatment, and prior to their transit through the Golgi. The recycling pool of newly synthesized anion exchangers is reflected in the steady-state distribution of the polypeptide. In addition to plasma membrane staining, anion exchanger antibodies stain a perinuclear compartment in erythroid cells. This perinuclear AE1-containing compartment is also stained by ankyrin antibodies and partially overlaps the membrane compartment stained by NBD C6-ceramide, a Golgi marker. Detergent extraction of erythroid cells in situ has suggested that a substantial fraction of the perinuclear pool of AE1 is cytoskeletal associated. The demonstration that erythroid anion exchangers interact with elements of the cytoskeleton during recycling to the Golgi suggests the cytoskeleton may be involved in the post-Golgi trafficking of this membrane transporter.


Asunto(s)
Antiportadores/sangre , Citoesqueleto/metabolismo , Células Precursoras Eritroides/metabolismo , Aparato de Golgi/metabolismo , Animales , Ancirinas/sangre , Antiportadores/química , Antiportadores/aislamiento & purificación , Transporte Biológico Activo/efectos de los fármacos , Brefeldino A/farmacología , Membrana Celular/metabolismo , Embrión de Pollo , Antiportadores de Cloruro-Bicarbonato , Detergentes , Técnicas In Vitro , Manosil-Glicoproteína Endo-beta-N-Acetilglucosaminidasa/farmacología , Procesamiento Proteico-Postraduccional , Solubilidad
8.
Am J Clin Oncol ; 21(2): 189-94, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9537210

RESUMEN

SK&F107647 is a synthetic hematoregulatory peptide (HP) increases both the number and function of progenitor cells, enabling improved survival after lethal myelosuppression, lethal fungal infection, and lethal herpes simplex virus infection in murine models. This Phase I single-blind placebo-controlled dose-rising crossover trial examined the efficacy of SK&F107647 in patients who had incurable solid tumor malignancies. Sixteen patients were treated. Six adverse events in 3 patients were considered to be possibly related to SK& F107647; all were mild to moderate in nature (mild nervousness and agitation at 0.01 ng/kg, moderate fever and mild nausea at 0.1 ng/kg, elevated hepatic enzymes at 0.1 ng/kg, and mild vomiting at 1.0 ng/kg). Plasma half-life was 2.44 hours (+/-1.07 standard deviation). The observed area volume of distribution was 16.7 L (+/-7.7 standard deviation) and clearance was 5.04 L/hour (+/-1.83 standard deviation). When administered as a single 2-hour intravenous infusion at doses ranging from 0.01 to 100 ng/kg, SK&F107647 is safe and well tolerated.


Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Oligopéptidos/uso terapéutico , Adyuvantes Inmunológicos/farmacocinética , Adulto , Anciano , Femenino , Hematopoyesis/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Oligopéptidos/farmacocinética
9.
Gene ; 173(2): 221-6, 1996 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-8964503

RESUMEN

Previous studies have demonstrated that three variant transcripts, AE1-3, AE1-4 and AE1-5, are derived from the AE1 gene in chicken kidney. These variant transcripts encode AE1 anion exchangers that possess alternative N-terminal cytoplasmic domains. To determine the mechanisms involved in generating these transcripts, a genomic clone, containing the unique sequences at the 5' ends of the AE1-4 and AE1-5 transcripts, was isolated. Characterization of this clone revealed that the sequences at the 5' ends of the AE1-3, AE1-4 and AE1-5 transcripts were each present with an approx. 1.2-kb BamHI fragment of the chicken AE1 gene. RNA blotting and RNase protection analyses using probes derived from this genomic clone have shown that the AE1-4 variant corresponds to the approx. 4.5-kb chicken kidney AE1 transcript, while the AE1-5 variant corresponds to the approx. 5.1-kb transcript. These studies have shown that the AE1-5 transcript extends further 5' than had been previously shown from cDNA cloning studies, and contains the sequence present at the 5' end of the AE1-4 transcript. In addition, primer extension analyses have shown that the variant kidney AE1 transcripts initiate transcription from a common site. This result indicates that the expression of the AE1-3, AE1-4, and AE1-5 transcripts is regulated by a single promoter, P3, that is distinct from the P1 and P2 erythroid-specific promoters of the chicken AE1 gene.


Asunto(s)
Empalme Alternativo , Antiportadores/genética , Riñón/metabolismo , Regiones Promotoras Genéticas , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Pollos , ADN , Datos de Secuencia Molecular
10.
J Biol Chem ; 271(15): 8895-902, 1996 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-8621532

RESUMEN

Molecular analyses have resulted in the isolation of two chicken stomach AE2 anion exchanger cDNAs, AE2-1 and AE2-2. The approximately 4.3-kilobase (kb) AE2-1 cDNA contains an open reading frame that encodes a predicted polypeptide of approximately 135 kDa that is homologous to AE2 anion exchangers from other species. The partial approximately 1.7-kb AE2-2 cDNA, which differs from the AE2-1 cDNA in two regions, would be predicted to encode an AE2 polypeptide with an alternative N-terminal cytoplasmic tail. Examination of the distribution of these variant transcripts has revealed that AE2 transcripts ranging in size from approximately 4.4 to approximately 7.3 kb accumulate in various adult tissues. However, in the stomach, the unique sequence at the 5'-end of AE2-1 is preferentially associated with transcripts that range in size from approximately 4.5 to approximately 4.9 kb, while the unique sequence at the 5'-end of AE2-2 is preferentially associated with the approximately 7.3-kb AE2 RNA species. In situ hybridization analyses have further revealed that AE2 transcripts accumulate to very high levels within the acid-secreting epithelial cells of the profound gland in the stomach and, to a lesser extent, within the mucus-secreting cells of the superficial gland that line the stomach lumen. This result suggests that AE2 anion exchangers are involved in the regulation of intracellular pH in each of these gastric epithelial cell types.


Asunto(s)
Proteínas de Transporte de Anión , Antiportadores , Mucosa Gástrica/metabolismo , Proteínas de la Membrana/genética , Empalme Alternativo , Secuencia de Aminoácidos , Animales , Aniones , Secuencia de Bases , Pollos , Clonación Molecular , ADN Complementario/genética , Expresión Génica , Hibridación in Situ , Datos de Secuencia Molecular , ARN Mensajero/genética , Proteínas SLC4A , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Distribución Tisular
11.
J Biol Chem ; 270(34): 19752-60, 1995 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-7649985

RESUMEN

Four variant AE1 anion exchangers with predicted molecular masses of approximately 99, approximately 102, approximately 104, and approximately 108 kDa are expressed in chicken erythroid cells. These variant polypeptides differ in sequence only at the N terminus of their cytoplasmic domains. Molecular analyses have shown that transcripts derived from both of the erythroid-specific promoters, P1 and P2, encode all four of these AE1 anion exchanger variants. However, quantitative RNase protection analyses have shown that the transcripts derived from the P1 promoter are much more prevalent than those derived from the P2 promoter. Reverse transcriptase polymerase chain reaction studies have indicated that the extensive diversity in the transcripts derived from the AE1 gene occurs both in primitive and definitive lineage erythroid cells. Transient transfection analyses using human erythroleukemia cells have investigated the functional significance of the alternative sequences at the N terminus of these variant exchangers. These studies have shown that the erythroid AE1 variants are sorted to different membrane compartments in these cells. The approximately 99- and approximately 102-kDa variants are primarily sorted to the plasma membrane, whereas the approximately 108-kDa variant is retained in a perinuclear compartment. These results suggest that the alternative N-terminal cytoplasmic sequences of these polypeptides may serve as signals to direct these variant transporters to different membrane compartments within cells.


Asunto(s)
Proteína 1 de Intercambio de Anión de Eritrocito/genética , Proteína 1 de Intercambio de Anión de Eritrocito/metabolismo , Eritrocitos/metabolismo , Variación Genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Pollos , ADN/genética , Humanos , Inmunohistoquímica , Líquido Intracelular/metabolismo , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/metabolismo , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal , Fracciones Subcelulares/metabolismo , Transfección , Células Tumorales Cultivadas
12.
Am J Physiol ; 268(3 Pt 2): F503-13, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7900851

RESUMEN

Immunoblotting analyses have demonstrated that antibodies specific for the chicken erythroid AE1 anion exchanger recognize multiple polypeptides ranging in size from approximately 95 to 112 kDa in chicken kidney. To determine the origin of this diversity, we have cloned and characterized the kidney AE1 anion exchangers. These studies have shown that the kidney AE1 polypeptides are encoded by at least three transcripts, AE1-3, AE1-4, and AE1-5, which differ from the erythroid AE1-1 and AE1-2 transcripts in the sequences present at their 5'-ends. The AE1-3 and AE1-5 transcripts encode predicted polypeptides of approximately 94 kDa, which are identical to the erythroid AE1-1 anion exchanger except for the absence of the 78 NH(2)-terminal amino acids of the AE1-1 polypeptide. In contrast, the AE1-4 transcript encodes a predicted polypeptide of approximately 101 kDa, whose 21 NH(2)-terminal amino acids are unique. Characterization of the AE1 cDNAs has suggested that the AE1-3 and AE1-4 transcripts are generated by alternative splicing of a single primary transcript, while DNA blotting analyses have shown that the putative transcription initiation sites of the variant AE1-4 and AE1-5 transcripts lie several kilobases downstream of the transcription initiation sites of the erythroid AE1-1 and AE1-2 transcripts. These results suggest that the pattern of accumulation of the variant kidney AE1 anion exchangers is regulated by a complex pattern of alternative transcriptional initiation and differential RNA splicing.


Asunto(s)
Proteína 1 de Intercambio de Anión de Eritrocito/genética , Secuencia de Aminoácidos , Animales , Proteína 1 de Intercambio de Anión de Eritrocito/química , Secuencia de Bases , Embrión de Pollo , Pollos , Mapeo Cromosómico , Clonación Molecular , Citoplasma/química , ADN Complementario/genética , Eritrocitos/química , Regulación de la Expresión Génica , Variación Genética , Riñón/química , Datos de Secuencia Molecular , Especificidad de Órganos , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Transcripción Genética
13.
Am J Hematol ; 42(2): 177-81, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8438878

RESUMEN

The serum ferritin (SERFER) may be elevated and misleading in the setting of chronic disease (chronic inflammation, liver disease, and neoplasm). The red cell ferritin (RBCFER) may be more stable in clinical situations that affect the SERFER. We compared the ability of SERFER and RBCFER to assess iron stores in these settings. Iron stores were defined by bone marrow aspirate staining. We studied 120 anemic (Hb < 14 g/dl) male patients. Twenty-eight (23%) were iron deficient based on the absence of marrow iron. The SERFER correlation with marrow iron stores (r = 0.58; P < 0.001) was better than the RBCFER (r = 0.36; P < 0.001). Cutoff values for the diagnosis of iron deficiency were determined by chi-square analysis (SERFER < 70 ng/ml; RBCFER < or = 4 ag/RBC). The sensitivity for detecting iron deficiency with SERFER (0.60) was less than RBCFER (0.82). The specificity of SERFER (0.90) was slightly better than RBCFER (0.83). Neither difference reached statistical significance (P > 0.05). The positive predictive value between the two assays was the same (SERFER 0.65 vs. RBCFER 0.59). The combination of SERFER < 70 ng/ml with RBCFER < or = 4 ag/RBC was more specific (0.97) when compared with the SERFER alone (0.90) (P = 0.04). In addition, the potential of this combination to predict iron deficiency (0.82) was higher than that seen with either SERFER (0.65) or the RBCFER (0.59). Our findings show that the RBCFER as a single assay is not anymore accurate than the SERFER. However, we find that the RBCFER can effectively complement the SERFER to either predict iron depletion or confirm the presence of bone marrow iron.


Asunto(s)
Anemia/metabolismo , Médula Ósea/metabolismo , Eritrocitos/metabolismo , Ferritinas/sangre , Hierro/metabolismo , Anemia/complicaciones , Anemia/diagnóstico , Enfermedad Crónica , Humanos , Hierro/sangre , Deficiencias de Hierro , Masculino , Sensibilidad y Especificidad
14.
Clin Nucl Med ; 17(6): 439-45, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1319861

RESUMEN

Tumor-associated radiolabeled monoclonal antibodies (MoAb) can detect neoplasms in a variety of settings. The authors conducted a study comparing the ability to detect and stage small cell lung carcinoma by using a Tc-99m labeled monoclonal antibody (NR-LU-10 Fab) (NeoRx Corp, Seattle, WA) with standard staging methods. Standard staging included a physical examination, chest x-ray, a battery of radionuclide scans and/or computerized tomographic studies (head, abdomen, and bone), and bone marrow examination. A total of 22 comparisons were performed in 17 patients (five patients had reevaluations after therapy). Fifty-four (74%) of the 73 lesions defined by standard staging were detected by the radiolabeled MoAb. Seven of eight patients (88%) classified by standard staging as having "limited stage" disease on presentation were concordantly "limited stage" by radioimmunoimaging. One patient deemed "limited stage" by standard staging was correctly upstaged (bone marrow involvement) as a result of the radiolabeled MoAb. Two patients found to have extensive disease at diagnosis were characterized as "limited stage" by the MoAb, for an overall staging accuracy of 0.88. Thirteen of 19 missed lesions were smaller than 2 cm (10 were smaller than 1 cm; 3 measured 1 to 2 cm). This comparative study shows that radioimmunoimaging by Tc-99m labeled NR-LU-10 Fab antibody is capable of complementing standard staging methods used in the evaluation of small cell lung carcinoma.


Asunto(s)
Carcinoma de Células Pequeñas/diagnóstico por imagen , Neoplasias Pulmonares/diagnóstico por imagen , Radioinmunodetección , Carcinoma de Células Pequeñas/patología , Carcinoma de Células Pequeñas/secundario , Estudios de Evaluación como Asunto , Humanos , Neoplasias Pulmonares/patología , Estadificación de Neoplasias , Tecnecio , Tomografía Computarizada de Emisión de Fotón Único
15.
Cancer ; 68(8): 1824-7, 1991 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-1913527

RESUMEN

The eosinophilic fibrohistiocytic lesion of bone marrow (EFLBM) is characterized by collections of elongated "fibrohistiocytic" cells in association with lymphocytes, eosinophils, and plasma cells. The fibrohistiocytic cells are mast cells, and many investigators include this lesion (EFLBM) as a localized form of mastocytosis. The etiology and clinical significance of these lesions remains unclear. The morphologic features of these lesions point to a wide differential diagnosis that includes Hodgkin's disease. Currently, however, there are no recorded cases of well-defined Hodgkin's disease with these lesions. A case of Hodgkin's disease in which such lesions complicated the interpretation of serial bone marrows is reported. This case illustrates how the presence of these lesions could potentially influence therapeutic intervention.


Asunto(s)
Médula Ósea/patología , Enfermedad de Hodgkin/patología , Eosinofilia/patología , Humanos , Masculino , Mastocitos/patología , Persona de Mediana Edad , Células de Reed-Sternberg/patología
16.
Clin Nucl Med ; 16(10): 732-6, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1660386

RESUMEN

The detection of metastatic disease confined to the bone marrow compartment has in the past been technically limited. We have identified excellent imaging of bone marrow metastases during the evaluation of a Tc-99m labeled monoclonal antibody (NR-LU-10 Fab) (NeoRx Corp., Seattle, WA). This occurred during a study to assess the monoclonal antibody's ability to detect sites of small cell cancer (primary and metastatic). The study by design compares areas seen by the monoclonal antibody scan with those found by standard staging methods in patients with small cell lung cancer. Standard staging included chest x-rays, bone scans, CT studies of the abdomen, and histologic examination of the bone marrow. Fifteen patients have been evaluated, four on two occasions, for a total of 19 monoclonal imaging studies. Metastasis to the marrow compartment was identified by the monoclonal imaging in all patients whose bone marrow biopsies were positive for small cell carcinoma, and it was primarily responsible for the eventual detection of extensive disease (marrow involvement) in one patient. Thus it appears that compartmental bone marrow imaging for metastatic disease is possible with immunoscintigraphy.


Asunto(s)
Médula Ósea/patología , Neoplasias Óseas/secundario , Carcinoma de Células Pequeñas/secundario , Neoplasias Pulmonares/diagnóstico por imagen , Radioinmunodetección , Médula Ósea/diagnóstico por imagen , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/patología , Carcinoma de Células Pequeñas/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Tecnecio
17.
J Clin Oncol ; 8(12): 2047-53, 1990 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2172474

RESUMEN

Published prognostic models for small-cell lung cancer (SCLC) have either combined limited- and extensive-stage patients or have not included standard anatomic staging information to assess the relative value of the knowledge of specific sites and number of sites of metastases in predicting survival in extensive-stage disease. We studied 136 extensive-stage patients in whom traditional staging procedures were performed and in whom other previously demonstrated significant pretreatment variables were determined. Using the Cox proportional hazards model, when all data were included, three variables were significant: performance status (PS) (P = .0001), number of sites of metastases (P = .0010), and age (P = .0029). A prognostic algorithm was developed using these variables, which divided the patients into three distinct groups. When the anatomic staging data were omitted, the serum albumin (P = .0313) was the only variable in addition to PS (P = .0001) and age (P = .0064) that was significant. An alternative algorithm using these three variables was nearly as predictive as the original. Therefore, in extensive-stage patients, reasonable pretreatment prognostic information can be obtained without using the number or specific sites of metastases as variables once the presence of distant metastases has been demonstrated.


Asunto(s)
Carcinoma de Células Pequeñas/patología , Neoplasias Pulmonares/patología , Estadificación de Neoplasias/métodos , Carcinoma de Células Pequeñas/mortalidad , Humanos , Neoplasias Pulmonares/mortalidad , Pronóstico , Estudios Prospectivos , Análisis de Supervivencia
18.
Med Sci Sports Exerc ; 21(6): 643-8, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2626086

RESUMEN

The current consensus is that runners commonly experience a mild anemia influenced by iron deficiency. We compared hematologic parameters of 72 (35 males and 37 females) runners with 48 (27 males and 21 females) nonrunners and assessed the impact of iron supplementation. Male runners had lower hemoglobin (Hb) values than male nonrunners (14.8 vs 15.3 g.dl-1) (P less than 0.05) regardless of iron usage. Female runners had higher (P = 0.05) Hb values than female controls (13.5 vs 12.8 g.dl-1). Female runners off iron had Hbs similar to controls off iron (P = 0.30). Iron parameters (total serum iron, TSI; total iron-binding capacity, TIBC; percent saturation of the TIBC, %sat TIBC; and serum ferritin) of runners vs controls, runners vs runners (on or off iron), and nonrunners vs nonrunners (on or off iron) were comparable except 1) male runners off iron had lower (P less than 0.05) %sat TIBC values (26%) than male runners on iron (34%) and 2) female runners taking iron had ferritin values (32 ng.ml-1) similar to those of female nonrunners taking iron (39 ng.ml-1) but higher (P less than 0.05) than their counterparts off iron (15 and 15 ng.ml-1, respectively). This study concludes that running affects Hb in a variable manner and suggests that the runner's iron status is similar to that of the general population.


Asunto(s)
Anemia Hipocrómica/etiología , Deficiencias de Hierro , Carrera , Adulto , Estudios Transversales , Femenino , Ferritinas/sangre , Pruebas Hematológicas , Humanos , Hierro/administración & dosificación , Hierro/sangre , Masculino
19.
Arch Intern Med ; 148(11): 2485-9, 1988 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3142382

RESUMEN

Blood transfusion is an integral part of the supportive care of patients with sickle cell diseases. The hazards of red blood cell alloimmunization and delayed hemolytic transfusion reactions (DHTRs) complicate the treatment of patients with sickle cell diseases, particularly since such reactions may be misinterpreted as a pain crisis, and, as a result, specific transfusion serologic studies may not be performed. The frequency of alloimmunization in this population has been the subject of several reports; however, the frequency of DHTRs is unknown. To determine the frequency of this event, we retrospectively reviewed the medical and transfusion service records of all adult patients with sickle cell diseases transfused during the six-year period from January 1980 to December 1985. Seventy-three adult patients with sickle cell diseases received transfusions. The prevalence of recognized DHTR was three (4%) of 73. Red blood cell alloimmunization was seen in 22 (30%) of 73 of the patients. The calculated risk of alloimmunization was 3.1% per unit of blood. These observations suggest that alloimmunization and clinically apparent DHTRs occur more frequently in patients with sickle cell diseases and support pretransfusion testing for at least Rh and Kell red blood cell antigens in patients who are at high risk of such events (patients who have formed an alloantibody or who are being enrolled in a transfusion program).


Asunto(s)
Anemia de Células Falciformes/terapia , Antígenos de Grupos Sanguíneos/inmunología , Incompatibilidad de Grupos Sanguíneos/etiología , Isoanticuerpos/análisis , Sistema del Grupo Sanguíneo de Kell/inmunología , Sistema del Grupo Sanguíneo Rh-Hr/inmunología , Reacción a la Transfusión , Adolescente , Adulto , Anemia de Células Falciformes/inmunología , Incompatibilidad de Grupos Sanguíneos/inmunología , Eritrocitos/inmunología , Femenino , Humanos , Masculino , Factores de Riesgo
20.
Am J Hematol ; 29(2): 79-84, 1988 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3189306

RESUMEN

There is currently little experience using a continuous intravenous infusion of low-dose cytosine arabinoside (LDARA-C) in the treatment of acute nonlymphocytic leukemia (ANLL). We report the results in 12 patients with ANLL described as either relapsed ANLL, ANLL with a preceding myelodysplastic phase, or ANLL in the elderly treated with 14 days of continuous intravenous LDARA-C (20 mg/m2/day). Complete responses (CR) were seen in five patients (42%) and partial responses (PR) in three patients (25%). Treatment resulted in overall and clonal cytoreduction, which was evident by serial bone marrow exams and bone marrow cytogenetic analysis. The ability to obtain a CR correlated with the finding of a low initial marrow cellularity (P less than .05). This study finds that continuous intravenous infusion of LDARA-C for ANLL can achieve response rates comparable to standard induction programs in a subset of patients traditionally defined as having a poor prognosis.


Asunto(s)
Citarabina/administración & dosificación , Leucemia Mieloide Aguda/tratamiento farmacológico , Adulto , Anciano , Médula Ósea/patología , Recuento de Células , Citarabina/efectos adversos , Citarabina/uso terapéutico , Esquema de Medicación , Femenino , Humanos , Infusiones Intravenosas , Cariotipificación , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Masculino , Pronóstico , Recurrencia , Inducción de Remisión
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