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1.
Phys Rev Lett ; 130(20): 203401, 2023 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-37267577

RESUMEN

We determine the phase diagram of strongly correlated fermions in the crossover from Bose-Einstein condensates of molecules (BEC) to Cooper pairs of fermions (BCS) utilizing an artificial neural network. By applying advanced image recognition techniques to the momentum distribution of the fermions, a quantity which has been widely considered as featureless for providing information about the condensed state, we measure the critical temperature and show that it exhibits a maximum on the bosonic side of the crossover. Additionally, we backanalyze the trained neural network and demonstrate that it interprets physically relevant quantities.

2.
Langmuir ; 36(24): 6668-6680, 2020 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-32437159

RESUMEN

Inverted/reverse hexagonal (HII) phases are of special interest in several fields of research, including nanomedicine. We used molecular dynamics (MD) simulation to study HII systems composed of dioleoylphosphatidylethanolamine (DOPE) and palmitoyloleoylphosphatidylethanolamine (POPE) at several hydration levels and temperatures. The effect of the hydration level on several HII structural parameters, including deuterium order parameters, was investigated. We further used MD simulations to estimate the maximum hydrations of DOPE and POPE HII lattices at several given temperatures. Finally, the effect of acyl chain unsaturation degree on the HII structure was studied via comparing the DOPE with POPE HII systems. In addition to MD simulations, we used deuterium nuclear magnetic resonance (2H NMR) and small-angle X-ray scattering (SAXS) experiments to measure the DOPE acyl chain order parameters, lattice plane distances, and the water core radius in HII phase DOPE samples at several temperatures in the presence of excess water. Structural parameters calculated from MD simulations are in excellent agreement with the experimental data. Dehydration decreases the radius of the water core. An increase in hydration level slightly increased the deuterium order parameter of lipids acyl chains, whereas an increase in temperature decreased it. Lipid cylinders undulated along the cylinder axis as a function of hydration level. The maximum hydration levels of PE HII phases at different temperatures were successfully predicted by MD simulations based on a single experimental measurement for the lattice plane distance in the presence of excess water. An increase in temperature decreases the maximum hydration and consequently the radius of the water core and lattice plane distances. Finally, DOPE formed HII structures with a higher curvature compared to POPE, as expected. We propose a general protocol for constructing computational HII systems that correspond to the experimental systems. This protocol could be used to study HII systems composed of molecules other than the PE systems used here and to improve and validate force field parameters by using the target data in the HII phase.


Asunto(s)
Fosfatidilcolinas , Fosfatidiletanolaminas , Membrana Dobles de Lípidos , Espectroscopía de Resonancia Magnética , Dispersión del Ángulo Pequeño , Temperatura , Difracción de Rayos X
3.
Neurocrit Care ; 33(1): 218-229, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-31820290

RESUMEN

BACKGROUND: Acute hydrocephalus is a common complication of aneurysmal subarachnoid hemorrhage (aSAH); however, attempts to predict shunt-dependent chronic hydrocephalus using clinical parameters have been equivocal. METHODS: Cohort study of aSAH is treated with external ventricular drainage (EVD) placement at our institution, 2001-2016, via logistic regression. EVD-related parameters included mean/total EVD output (days 0-2), EVD days, EVD days ≤ 5 mmHg, and wean/clamp fails. aSAH outcomes assessed included ventriculoperitoneal shunt (VPS) placement, delayed cerebral ischemia (DCI), radiographic infarction (RI), symptomatic vasospasm (SV), age, and aSAH grades. RESULTS: Two hundred and ten aSAH patients underwent EVD treatment for a median 12 days (range 1-54); 85 required VPS (40%). On univariate analysis, EVD output, total EVD days, EVD days ≤ 5 mmHg, and wean/clamp trial failures were significantly associated with VPS placement (p < 0.01 for all parameters). No EVD output parameter demonstrated a significant association with DCI, RI, or SV. On multivariate analysis, EVD output was a significant predictor of VPS placement, after adjusting for age and clinical and radiological grades; the optimal threshold for predicting VPS placement was mean daily output > 204 ml on days 0-2 (OR 2.59, 95% CI 1.31-5.07). Multiple wean failures were associated with unfavorable functional outcome, after adjusting for age, grade, and VPS placement (OR 1.65, 95% CI 1.10-2.47). We developed a score incorporating age, grade and EVD parameters (MAGE) for predicting VPS placement after aSAH. CONCLUSIONS: EVD output parameters and wean/clamp trial failures predicted shunt dependence in an age- and grade-adjusted multivariable model. Early VPS placement may be warranted in patients with MAGE score ≥ 4, particularly following 2 failed wean trials.


Asunto(s)
Aneurisma Roto/terapia , Isquemia Encefálica/epidemiología , Infarto Cerebral/epidemiología , Hidrocefalia/cirugía , Aneurisma Intracraneal/terapia , Hemorragia Subaracnoidea/terapia , Vasoespasmo Intracraneal/epidemiología , Derivación Ventriculoperitoneal/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Aneurisma Roto/complicaciones , Infarto Cerebral/diagnóstico por imagen , Estudios de Cohortes , Drenaje , Femenino , Humanos , Hidrocefalia/etiología , Aneurisma Intracraneal/complicaciones , Masculino , Persona de Mediana Edad , Modelos Teóricos , Medición de Riesgo , Rotura Espontánea , Hemorragia Subaracnoidea/complicaciones , Ventriculostomía , Adulto Joven
7.
N Engl J Med ; 361(24): 2309-17, 2009 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-20007560

RESUMEN

BACKGROUND: Myeloablative allogeneic hematopoietic stem-cell transplantation is curative in children with sickle cell disease, but in adults the procedure is unduly toxic. Graft rejection and graft-versus-host disease (GVHD) are additional barriers to its success. We performed nonmyeloablative stem-cell transplantation in adults with sickle cell disease. METHODS: Ten adults (age range, 16 to 45 years) with severe sickle cell disease underwent nonmyeloablative transplantation with CD34+ peripheral-blood stem cells, mobilized by granulocyte colony-stimulating factor (G-CSF), which were obtained from HLA-matched siblings. The patients received 300 cGy of total-body irradiation plus alemtuzumab before transplantation, and sirolimus was administered afterward. RESULTS: All 10 patients were alive at a median follow-up of 30 months after transplantation (range, 15 to 54). Nine patients had long-term, stable donor lymphohematopoietic engraftment at levels that sufficed to reverse the sickle cell disease phenotype. Mean (+/-SE) donor-recipient chimerism for T cells (CD3+) and myeloid cells (CD14+15+) was 53.3+/-8.6% and 83.3+/-10.3%, respectively, in the nine patients whose grafts were successful. Hemoglobin values before transplantation and at the last follow-up assessment were 9.0+/-0.3 and 12.6+/-0.5 g per deciliter, respectively. Serious adverse events included the narcotic-withdrawal syndrome and sirolimus-associated pneumonitis and arthralgia. Neither acute nor chronic GVHD developed in any patient. CONCLUSIONS: A protocol for nonmyeloablative allogeneic hematopoietic stem-cell transplantation that includes total-body irradiation and treatment with alemtuzumab and sirolimus can achieve stable, mixed donor-recipient chimerism and reverse the sickle cell phenotype. (ClinicalTrials.gov number, NCT00061568.)


Asunto(s)
Anemia de Células Falciformes/terapia , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Antineoplásicos/uso terapéutico , Antineoplásicos/uso terapéutico , Trasplante de Células Madre Hematopoyéticas , Sirolimus/uso terapéutico , Acondicionamiento Pretrasplante/métodos , Irradiación Corporal Total , Adolescente , Adulto , Alemtuzumab , Anticuerpos Monoclonales Humanizados , Antígenos CD34 , Antineoplásicos/efectos adversos , Protocolos Clínicos , Femenino , Estudios de Seguimiento , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/métodos , Hemoglobinas/análisis , Prueba de Histocompatibilidad , Humanos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Narcóticos/efectos adversos , Neutrófilos , Sirolimus/efectos adversos , Síndrome de Abstinencia a Sustancias , Quimera por Trasplante , Trasplante Homólogo , Adulto Joven
8.
AJNR Am J Neuroradiol ; 43(6): 817-822, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35589138

RESUMEN

Phosphaturic mesenchymal tumors (PMTs) are neoplasms associated with tumor-induced osteomalacia. Patients typically present with pathologic fractures in the setting of chronic hypophosphatemic hyperphosphaturic osteomalacia, as well as gradual muscle weakness, bone pain, and difficulty walking. Because of their rarity and nonspecific symptomatology, phosphaturic mesenchymal tumors often go undiagnosed for years. Even when discovered on imaging, the tumors can be diagnostically challenging for radiologists. Phosphaturic mesenchymal tumors often tend to be small and can be located nearly anywhere in the body, and, therefore, can mimic many other tumors. This case highlights the imaging and pathologic markers of a phosphaturic mesenchymal tumor, often found in a patient with tumor-induced osteomalacia.


Asunto(s)
Mesenquimoma , Neoplasias de Tejido Conjuntivo , Osteomalacia , Síndromes Paraneoplásicos , Humanos , Mesenquimoma/diagnóstico , Mesenquimoma/diagnóstico por imagen , Neoplasias de Tejido Conjuntivo/diagnóstico , Neoplasias de Tejido Conjuntivo/diagnóstico por imagen , Osteomalacia/diagnóstico por imagen , Osteomalacia/etiología , Síndromes Paraneoplásicos/complicaciones , Síndromes Paraneoplásicos/diagnóstico por imagen
9.
Rev Sci Instrum ; 92(9): 093202, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34598519

RESUMEN

Cold atom experiments commonly use broad magnetic Feshbach resonances to manipulate the interaction between atoms. In order to induce quantum dynamics by a change in the interaction strength, rapid (∼µs) magnetic field changes over several tens of Gauss are required. Here, we present a compact design of a coil and its control circuit for a change in the magnetic field up to 36 G in 3 µs. The setup comprises two concentric solenoids with minimal space requirements, which can be readily added to existing apparatuses. This design makes the observation of non-equilibrium physics with broad Feshbach resonances accessible.

10.
Environ Pollut ; 280: 116953, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33784566

RESUMEN

Recent studies have shown that sub-lethal doses of herbicides may affect plant flowering, however, no study has established a direct relationship between the concentrations of deposited herbicide and plant flowering. Here the aim was to investigate the relationship between herbicide spray drift deposited on non-target plants and plant flowering in a realistic agro-ecosystem setting. The concentrations of the herbicide glyphosate deposited on plants were estimated by measuring the concentration of a dye tracer applied together with the herbicide. The estimated maximal and average deposition of glyphosate within the experimental area corresponded to 30 g glyphosate/ha (2.08% of the label rate of 1440 g a.i./ha) and 2.4 g glyphosate/ha (0.15% label rate), respectively, and the concentrations decreased rapidly with increasing distance from the spraying track. However, there were not a unique relation between distance and deposition, which indicate that heterogeneities of turbulence, wind speed and/or direction can strongly influence the deposition from 1 min to another during spraying. The effects of glyphosate on cumulative flower numbers and flowering time were modelled using Gompertz growth models on four non-target species. Glyphosate had a significantly negative effect on the cumulative number of flowers on Trifolium pratense and Lotus corniculatus, whereas there were no significant effects on Trifolium repens, and a positive, but non-significant, effect on number of flowers on Cichorium intybus. Glyphosate did not affect the flowering time of any of the four species significantly. Lack of floral resources is known to be of major importance for pollinator declines. The implications of the presented results for pesticide risk assessment are discussed.


Asunto(s)
Ecosistema , Herbicidas , Glicina/análogos & derivados , Glicina/toxicidad , Herbicidas/toxicidad , Plantas , Glifosato
11.
J Exp Med ; 168(1): 229-45, 1988 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-2840480

RESUMEN

Southern blot analyses revealed that cells from nearly 30% of childhood B cell precursor acute lymphoblastic leukemias (ALLs) contained more than two rearranged, nongermline bands for Ig heavy chain genes. DNA corresponding to these bands was molecularly cloned from two cases which showed three and seven rearranged bands, respectively. Nucleotide sequence analysis of the cloned DNA demonstrated that each band represented different VDJ or DJ rearrangements. While the same DJ joints were shared by several rearrangements, different DJ joints were found in the majority of rearrangements, precluding V region substitution as an explanation for the multiplicity of heavy chain rearrangements in these leukemias. Most of the V region segments involved in these rearrangements were restricted to VH region families that have been shown previously to be preferentially rearranged in human fetal B lineage cells. Sequence analysis of multiple copies of the same VDJ rearrangements from different cells revealed no somatic mutation, a mechanism responsible for detection of extra rearranged Ig DNA bands in certain other B lineage tumors. The data suggest that in some cases of ALL Ig heavy chain genes begin and continue to rearrange de novo within the neoplastic B cell precursor populations derived from an original malignant cell transformed at a stem cell stage of differentiation.


Asunto(s)
Linfocitos B/inmunología , Genes de Inmunoglobulinas , Células Madre Hematopoyéticas/inmunología , Leucemia Linfoide/inmunología , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN/genética , Enzimas de Restricción del ADN , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Datos de Secuencia Molecular , Mutación , Hibridación de Ácido Nucleico , Homología de Secuencia de Ácido Nucleico
12.
J Exp Med ; 169(5): 1557-64, 1989 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-2541219

RESUMEN

CTL are thought to play a role in the elimination of transformed cells in vivo. The effectiveness of such CTL is in part dependent on recognition of tumor specific antigens. Among the best characterized tumor-specific antigens are the unique or idiotypic determinants on the Ig of B cell lymphomas. Here we describe the generation and properties of human CTL specific for the idiotype on autologous B cell tumors. These cells are CD3+,CD4-,CD8- and express the delta chain of the TCR. Such cells may prove useful in tumor-specific adoptive therapy.


Asunto(s)
Antígenos de Neoplasias/inmunología , Linfoma de Burkitt/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T Citotóxicos/inmunología , Adolescente , Anticuerpos Monoclonales , Antígenos de Diferenciación/análisis , Antígenos de Diferenciación/inmunología , Antígenos de Diferenciación de Linfocitos T/análisis , Antígenos de Diferenciación de Linfocitos T/inmunología , Linfocitos B/inmunología , Complejo CD3 , Antígenos CD8 , Línea Celular Transformada , Niño , Femenino , Antígenos HLA-DR/análisis , Antígeno HLA-DR1 , Herpesvirus Humano 4 , Humanos , Idiotipos de Inmunoglobulinas/inmunología , Antígeno-1 Asociado a Función de Linfocito , Masculino , Receptores de Antígenos de Linfocitos T/análisis , Células Tumorales Cultivadas
13.
Science ; 234(4773): 197-200, 1986 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-3092355

RESUMEN

An inversion of chromosome 14 present in the tumor cells of a patient with childhood acute lymphoblastic leukemia of B-cell lineage was shown to be the result of a site-specific recombination event between an immunoglobulin heavy-chain variable gene and the joining segment of a T-cell receptor alpha chain. This rearrangement resulted in the formation of a hybrid gene, part immunoglobulin and part T-cell receptor. Furthermore, this hybrid gene was transcribed into messenger RNA with a completely open reading frame. Thus, two loci felt to be normally activated at distinct and disparate points in lymphocyte development were unified and expressed in this tumor.


Asunto(s)
Linfocitos B , Inversión Cromosómica , Cadenas Pesadas de Inmunoglobulina/genética , Leucemia Linfoide/genética , Receptores de Antígenos de Linfocitos T/genética , Diferenciación Celular , Niño , Cromosomas Humanos 13-15 , Humanos , Leucemia Linfoide/patología , Modelos Genéticos , Recombinación Genética , Linfocitos T , Transcripción Genética
14.
Br J Sports Med ; 43(9): 685-9, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19734503

RESUMEN

Sudden cardiac death in the athlete is uncommon but extremely visible. In athletes under age 30, genetic heart disease, including hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and ion channel disorders account for the majority of the deaths. Commotio cordis, involving blunt trauma to the chest leading to ventricular fibrillation, is also a leading cause of sudden cardiac death in young athletes. As the athlete ages, coronary atherosclerosis contributes to an increasing incidence of sudden death during sporting activities. For athletes with aborted sudden death or arrhythmia-related syncope, an implantable cardioverter defibrillator is generally indicated, and they should be restricted from most competitive sports. Participation in competitive athletics for athletes with heart disease should generally follow the recently published 36th Bethesda Conference Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities.


Asunto(s)
Muerte Súbita Cardíaca/prevención & control , Cardiopatías/complicaciones , Deportes , Adulto , Factores de Edad , Conducta Competitiva , Muerte Súbita Cardíaca/etiología , Femenino , Humanos , Masculino , Factores de Riesgo , Adulto Joven
15.
J Clin Invest ; 76(1): 248-53, 1985 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2410458

RESUMEN

We have examined the expression of the Leu-4 (T3) antigen on the cell surface and in the cytoplasm of blast cells from 23 patients with T cell acute lymphoblastic leukemia and T cell lymphoblastic lymphoma. In the majority of cases (17), the Leu-4 antigen was absent from the cell surface; however, in 16 of these 17 cases, blast cells demonstrated cytoplasmic expression of Leu-4. This discordance between surface and cytoplasmic expression of Leu-4 was also found in thymocytes and appeared to be restricted to Leu-4, in that tests of other T cell antigens rarely revealed discordance between surface and cytoplasmic expression. To study further the cytoplasmic determinant identified by anti-Leu-4 in malignant T lymphoblasts, immunoprecipitation studies were performed that utilized biosynthetic labeling of established T cell lines derived from T lymphoblastic malignancies. By one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, identical Leu-4 polypeptide families were immunoprecipitated from surface Leu-4+ and surface Leu-4-/cytoplasmic Leu-4+ cell lines. Because T lymphoblastic malignancies represent proliferations of immature T cells, and because the cases studied demonstrated surface phenotypes corresponding to all of the proposed stages of T cell ontogeny, it appears that cytoplasmic expression of Leu-4 occurs early in T cell development. The reason for the failure of these immature T cells to transport the Leu-4 molecule to their surface remains to be elucidated.


Asunto(s)
Antígenos de Superficie/análisis , Leucemia Linfoide/inmunología , Linfoma/inmunología , Linfocitos T/inmunología , Antígenos de Diferenciación de Linfocitos T , Niño , Citoplasma/inmunología , Epítopos , Humanos , Peso Molecular
16.
Cancer Res ; 48(10): 2876-9, 1988 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-3162827

RESUMEN

The Philadelphia (Ph) chromosome translocation which is classically observed in chronic myeloid leukemia (CML) is sporadically found in acute lymphoblastic leukemia (ALL). In CML the translocation breakpoint on chromosome 22 is within the breakpoint cluster region, while in childhood ALL, no detectable change in breakpoint cluster region is routinely observed. In order to investigate the nature of this difference, we have established and characterized two cell lines from a child with Ph positive ALL. The cell lines have retained the cytochemical staining pattern, enzyme activity, monoclonal antibody profile, and immunoglobulin gene rearrangements of the child's malignant cells. The cell lines had the same Ph translocation t(9;22) (q34;q11) as the child's malignant cells along with additional chromosome changes. Southern blot analysis showed that the Ph translocation did not involve the 5.8-kilobase breakpoint cluster region segment characteristically seen in CML. The cell lines reported here will be a valuable resource in ascertaining the biological significance of the Ph translocation seen in ALL.


Asunto(s)
Leucemia Linfoide/genética , Cromosoma Filadelfia , Adenosina Desaminasa/análisis , Antígenos de Neoplasias/análisis , Niño , Humanos , Cariotipificación , Masculino , Proto-Oncogenes , Recombinación Genética , Células Tumorales Cultivadas
17.
Cancer Res ; 50(22): 7371-5, 1990 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-2224864

RESUMEN

We have investigated the functional relevance of c-myb expression for DNA synthesis in patients' T-leukemia cells. [3H]Thymidine incorporation assays of 32 patients' leukemia cells exposed in vitro to c-myb sense or antisense oligodeoxynucleotides served to define two groups of patients: a responder group whose leukemia cells showed 2- to 16-fold lower levels of [3H]thymidine incorporation in c-myb antisense-treated cultures than in c-myb sense-treated cultures (20 patients) and a nonresponder group whose cells showed comparable [3H]thymidine incorporation levels in either c-myb sense- or antisense-treated cultures (12 patients). Down-regulation of c-myb mRNA levels in cells exposed to c-myb antisense oligodeoxynucleotides was comparable in both groups of patients, indicating that differential sensitivity to c-myb antisense oligodeoxynucleotides was not due to differential uptake of these oligodeoxynucleotides. DNA polymerase alpha mRNA levels were down-regulated in cells from the responders but were unaffected in the nonresponder group. These results suggest that c-myb is required for DNA synthesis in cells of many but not all T-leukemia patients and that leukemia cells in which DNA synthesis is not inhibited despite down-regulation of c-myb expression may have undergone some genetic change(s) that obviate(s) the requirement for myb protein.


Asunto(s)
ADN de Neoplasias/biosíntesis , Leucemia-Linfoma de Células T del Adulto/patología , Proteínas Proto-Oncogénicas/genética , Secuencia de Bases , Northern Blotting , ADN Polimerasa II/genética , ADN sin Sentido/farmacología , Expresión Génica , Humanos , Leucemia-Linfoma de Células T del Adulto/genética , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos/farmacología , Proteínas Proto-Oncogénicas c-myb , ARN Mensajero/genética , ARN Neoplásico/genética , Microglobulina beta-2/genética
18.
Cancer Res ; 44(12 Pt 1): 5657-60, 1984 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6437672

RESUMEN

Recently, four distinct cell lines were established from patients whose malignancies had been defined by immunological and biochemical markers. Each patient had a distinct subtype of a T-cell cancer, and each possessed elevated adenosine deaminase and reduced nucleoside phosphorylase activity. Cell lines cultured in vitro possessed the same basic immunophenotype and biochemical enzyme activity as the patients' original malignant cells. In a direct comparison of the immunophenotype of the cell lines and the patients' malignant cells, full concordance existed for 48 of 52 paired antibody tests performed. However, when compared to the corresponding patient's sample, each cell line showed some minor changes in antigen expression or enzyme level. Antigen loss, de novo antigen expression, or elevated adenosine deaminase levels occurred in the cell lines, and these changes were stable on repeated analysis. While there was good general concordance between the patient's cancer and the established cell line, minor biological differences in the cell lines may reflect cellular maturation or subpopulation selection in vitro.


Asunto(s)
Adenosina Desaminasa/análisis , Antígenos de Neoplasias/análisis , Leucemia Linfoide/enzimología , Leucemia Linfoide/inmunología , Linfoma/enzimología , Linfoma/inmunología , Nucleósido Desaminasas/análisis , Pentosiltransferasa/análisis , Purina-Nucleósido Fosforilasa/análisis , Linfocitos T/inmunología , Anticuerpos Monoclonales , Línea Celular , Citometría de Flujo , Humanos
19.
Cancer Res ; 57(5): 832-6, 1997 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-9041181

RESUMEN

Frequent deletion of chromosome 9p21 in many cancers has suggested the presence of tumor suppressor genes in this region. Two genes mapping to 9p21, p15 and p16, encode inhibitors for cyclin-dependent kinases 4 and 6. We recently found that in T-cell acute lymphoblastic leukemia (T-ALL), both the p15 and p16 genes are deleted at a high frequency, with p16 gene deletion occurring slightly more frequently than p15 gene deletion. We now show that in addition to deletion, the p15 gene is preferentially hypermethylated at a 5' CpG island, which has been shown previously to be associated with loss of transcription of this gene. The p15 gene was methylated in 38% (17 of 45) of T-ALL patients at diagnosis and in 22% (7 of 32) of patients at relapse. On the other hand, methylation of the p16 gene was a rare event, occurring in 4% (2 of 49) of patients at diagnosis and in none (0 of 30) at relapse. The overall rates of alteration occurring in at least one allele of the p15 gene is 84% at diagnosis and 88% at relapse. These rates are as high as, if not greater than, those for the p16 gene (80% at diagnosis and 74% at relapse). In fact, such alterations involve both alleles in the majority of samples: 76% for p15 and 67% for p16 at diagnosis. All together, more than one-half (56%) of T-ALL samples harbor alterations in both alleles of both p15 and p16. These results lend strong support for a role of both p15 and p16 as tumor suppressors in T-ALL.


Asunto(s)
Proteínas Portadoras/genética , Proteínas de Ciclo Celular , Leucemia-Linfoma de Células T del Adulto/genética , Proteínas Supresoras de Tumor , Mapeo Cromosómico , Cromosomas Humanos Par 9 , Inhibidor p15 de las Quinasas Dependientes de la Ciclina , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Metilación de ADN , ADN de Neoplasias/genética , Exones , Regulación Neoplásica de la Expresión Génica , Humanos , Mapeo Restrictivo , Eliminación de Secuencia
20.
Cancer Res ; 47(6): 1652-6, 1987 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-3469019

RESUMEN

This paper describes the establishment and characterization of a new cell line (SUP-B7) which was established from a child with "common" acute lymphoblastic leukemia. The SUP-B7 cells (and the patient's tumor) have been characterized by cytochemical staining, monoclonal antibodies, enzyme analyses, gene rearrangement studies, and karyotype analysis. The SUP-B7 cells are periodic acid-Schiff positive, common acute lymphoblastic leukemia antigen positive, and terminal deoxynucleotidyl transferase positive, and they lack the Epstein-Barr virus genome. In addition, the SUP-B7 cells lack cytoplasmic and surface immunoglobulins, and the immunoglobulin gene rearrangement studies showed rearranged heavy chain genes with germ line light chain genes. Concordance between the cell line and the patient's tumor was established by the immunoglobulin gene rearrangement studies. Using Southern blot analysis of the DNA from the patient's tumor and the SUP-B7 cells, there was comigration of the bands representing the rearranged immunoglobulin heavy chain gene. In addition, the SUP-B7 cells possess a single chromosome abnormality: del(3)(q26q28), with the chromosome breakpoint at or near the transferrin receptor gene. Since the SUP-B7 cell line is concordant with the patient's malignancy and since these cells possess a single chromosomal abnormality, the SUP-B7 cell line may be a useful tool in determining the biological significance of the chromosome deletion: del(3)(q26q28).


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 3 , Leucemia Linfoide/patología , Antígenos/análisis , Línea Celular , Preescolar , Femenino , Humanos , Inmunoglobulinas/genética , Cariotipificación , Leucemia Linfoide/genética , Leucemia Linfoide/inmunología , Recombinación Genética
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