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1.
Occup Med (Lond) ; 68(1): 38-45, 2018 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-29390161

RESUMEN

Background: Working Health Service Scotland (WHSS) supports the self-employed and employees of small and medium-sized enterprises (SMEs) in Scotland with a health condition affecting their ability to work, who are either absent or at risk of becoming absent due to it. Aims: To evaluate the impact on health and work outcomes of WHSS clients over a 4-year period. Methods: Data were collected at enrolment, entry, discharge and follow-up at 3 and 6 months after discharge. Clients completed up to three validated health questionnaires at entry and discharge-EuroQol five dimensions (EQ-5D) and visual analogue scale (VAS); Hospital Anxiety and Depression Scale (HADS); and Canadian Occupational Performance Measure (COPM). Results: A total of 13463 referrals occurred in the 4-year period; 11748 (87%) were eligible and completed entry assessment and 60% of the latter completed discharge paperwork. The majority of referrals were due to musculoskeletal conditions (84%) while 12% were referred with mental health conditions. Almost a fifth (18%) of cases were absent at entry and back at work at discharge. Work days lost while in WHSS was associated with age, length of absence prior to entering WHSS, primary health condition and time in programme. All health measures showed significant improvements from entry to discharge. Improvement in general health was sustained at 3- and 6-month follow-up. Conclusions: The WHSS evaluation findings indicate that participation was associated with positive changes to health and return-to-work. The extent of the positive change in health measures and work ability can be highly important economically for employees and employers.


Asunto(s)
Salud Laboral/estadística & datos numéricos , Salud Laboral/normas , Reinserción al Trabajo/estadística & datos numéricos , Adulto , Canadá/epidemiología , Análisis Costo-Beneficio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Musculoesqueléticas/epidemiología , Salud Laboral/tendencias , Calidad de Vida , Escocia , Encuestas y Cuestionarios
2.
J Comput Aided Mol Des ; 28(2): 111-22, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24584482

RESUMEN

A proficient metaheuristic approach viz., particle swarm optimization coupled with negative factor counting technique and inverse iteration method has been employed for designing novel binary and ternary copolymers based on thiophene, pyrrole and furan skeletons. A comparative study of the electronic structures and conduction properties of neutral heterocyclic copolymers and their benzene substituted analogues is inferred using the band structure results derived from ab-initio Hartree-Fock crystal orbital calculations. The band gap value decreases as a result of substitution on the polymer backbone due to increased quinoid contributions which is expected to enhance the intrinsic conductivity of the resulting copolymers. In general, it has been found that HOMO energies have a more decisive influence than LUMO energies on the relative fraction of constituents of the respective low band gap copolymers. The trends in the electronic properties of the respective copolymers are also verified and discussed with the help of density of states. These results can help streamline scrupulous synthetic efforts providing a potent route for molecular engineering of sustainable and efficient electronic materials.


Asunto(s)
Furanos/química , Modelos Moleculares , Polímeros/química , Pirroles/química , Tiofenos/química
3.
J Pharm Biomed Anal ; 47(2): 248-54, 2008 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-18280078

RESUMEN

Indinavir sulphate is a potent and specific protease inhibitor of human immunodeficiency virus (HIV). It is used for the treatment of acquired immune deficiency syndrome (AIDS). At elevated temperature the drug which otherwise remains crystalline undergoes a phase transition to an amorphous phase to form degradation products. In the present study, thermal stability of indinavir sulphate is evaluated using diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Infrared spectra of the drug before and after the exposure to thermal radiation at different temperatures were acquired in the diffuse reflectance mode using a Fourier transform infrared (FTIR) spectrophotometer. The differential scanning calorimetry (DSC) and the X-ray diffraction (XRD) studies were used as complimentary techniques to adequately implement and assist the interpretation of the infrared spectroscopy results. The DRIFT spectra reveal that the drug remains stable up to 100 degrees C, degrades slightly at 125 degrees C and undergoes complete degradation at about 150 degrees C to produce degradation products. The degradation products can easily be characterized using the infrared spectra.


Asunto(s)
Inhibidores de la Proteasa del VIH/análisis , Indinavir/análisis , Espectrofotometría Infrarroja/métodos , Tecnología Farmacéutica , Rastreo Diferencial de Calorimetría/métodos , Estabilidad de Medicamentos , Inhibidores de la Proteasa del VIH/química , Humanos , Indinavir/química , Estructura Molecular , Difracción de Polvo/métodos , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura
4.
J Clin Invest ; 73(2): 587-92, 1984 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-6607934

RESUMEN

B cell chronic lymphocytic leukemia (CLL) cells appear to be arrested in their differentiation so that little immunoglobulin is secreted in most cases. To determine their capacity for further differentiation we stimulated cells from a series of 10 cases of CLL with a phorbol ester and assayed for production of immunoglobulin protein, accumulation of immunoglobulin mRNA, and alterations in cell surface markers. We found that cells from all cases were induced to secret monoclonal immunoglobulin of the same heavy and light chain type as the surface membrane immunoglobulin type. Immunoglobulin secretion was preceded by a rapid increase in the levels of mRNA coding for IgM, predominantly the secretory form, mu s-mRNA, rather than the membrane form, mu m-mRNA. A similar selection of mu s- over mu m-mRNA is known to occur in plasma cells by a mechanism of differential processing of mRNA from a single mu-chain gene. Except for a decline in the expression of surface IgD, cell surface determinants remained unaffected both in terms of the percentage of positive cells and the relative number of sites per cell. In contrast to previous studies, these results indicate that CLL cells consistently retain the capacity to further differentiate toward plasma cells and secrete immunoglobulin. The immunoglobulin secretion is mediated, at least in part, by a developmentally regulated increment in mu s-mRNA.


Asunto(s)
Linfocitos B/inmunología , Inmunoglobulinas/genética , Leucemia Linfoide/inmunología , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Inmunoglobulina M/genética , Inmunoglobulinas/metabolismo , ARN Mensajero/metabolismo , Acetato de Tetradecanoilforbol/farmacología
5.
J Clin Invest ; 71(2): 301-13, 1983 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-6401769

RESUMEN

We have explored the relationship among immunoglobulin gene rearrangement, cytoplasmic immunoglobulin production, and cell surface antigen expression within 37 cases of acute lymphocytic leukemia. All 12 cases of the T cell type had germ-line kappa and lambda genes and 11 of 12 had germ-line heavy chain genes. In contrast, all 25 cases of the "non-T, non-B" classification, which lacked both definitive T cell markers and surface immunoglobulin, had rearranged immunoglobulin genes, indicating that they represent precursor cells already committed to the B cell lineage at the gene level. 14 had rearranged heavy chain genes, yet retained germ-line light chain genes, whereas 11 cases had both heavy and light chain gene reorganizations. All patterns of immunoglobulin gene rearrangement predicted by a model that proceeds from heavy chain gene recombination to light chain genes were observed. Despite the uniform presence of rearranged immunoglobulin genes, only five cases produced cytoplasmic mu-chain, one exceptional case produced gamma-chain, and another produced only lambda-chain. The cases of B cell precursor type that do not produce immunoglobulin may represent cells that frequently possess ineffectively rearranged immunoglobulin genes. Included in this group may be a set of cells trapped within the B cell precursor series because their ineffective rearrangements have eliminated certain gene subsegments necessary for the assemblage of an effective heavy chain gene. All seven cases of the non-T, non-B subgroup that bore HLA-DR but lacked CALLA (the common acute lymphocytic leukemia-associated antigen) represented the earliest recognizable stage of B cell precursors with rearranged heavy chain genes but germ-line light chain genes. Correlations here suggest that cells entering B cell development express HLA-DR and rearrange heavy chain genes before the expression of a B cell-associated antigen recognized by the antibody BA-1, the antigen CALLA, and any subsequent light chain gene rearrangements.


Asunto(s)
Linfocitos B/inmunología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/inmunología , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos T/genética , Linfocitos T/inmunología , Genes , Código Genético , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Fenotipo , Recombinación Genética
6.
Cancer Res ; 47(10): 2537-42, 1987 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-3032407

RESUMEN

A 2.8-kilobase major breakpoint region on chromosome segment 18q21 is the site of most t(14;18) translocations typical of human follicular lymphomas. Breaks are focused at the 5' end of joining (JH) regions of immunoglobulin (Ig) on chromosome 14, indicating that the translocation occurs at a pre-B-cell stage during attempted heavy (H) chain joining. A new gene from 18q21 (Bcl-2) is placed in the H chain locus creating a unique, translocation-specific JH;18q21 rearrangement that presumably represents a transformation event. In addition, normal Ig gene joining occurs in a H before light (L) chain and K before lambda cascade, creating ordered clonal markers. These serial markers were examined to determine if variations in Ig gene patterns during the natural history of lymphomas represent the emergence of truly separate neoplasms or heterogeneity of a single neoplasm. We examined 45 serial biopsies from 16 B follicular lymphoma patients; six cases showed variation in Ig gene patterns over time. Seven individuals had a detectable JH;18q21 rearrangement present, and it remained unchanged over 5-10 years. Further rearrangements of H chain genes occurred on the normal chromosome 14 within evolving subclones of the original tumor. Lambda L chains also underwent additional rearrangements in two instances, while K gene patterns remained unchanged. All variations in the normal H and L chain genes were 2 degrees rearrangements occurring at a mature B-cell stage following the initial successful rearrangement of a H and L chain. In contrast the t(14;18) breakpoint was conserved in each individual, indicating that evolving neoplastic subpopulations arose from a common clonal progenitor cell.


Asunto(s)
Inmunoglobulinas/genética , Linfoma/genética , Alelos , Linfocitos B , Cromosomas Humanos Par 14 , Cromosomas Humanos Par 18 , Cromosomas Humanos Par 21 , Células Clonales , Enzimas de Restricción del ADN/metabolismo , Desoxirribonucleasa BamHI , Desoxirribonucleasa EcoRI , Desoxirribonucleasa HindIII , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/genética , Ganglios Linfáticos/patología , Linfoma/inmunología , Translocación Genética
7.
Oncogene ; 5(2): 233-5, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2181381

RESUMEN

The t(14; 18) chromosomal translocation of human follicular lymphoma recombines the bcl-2 gene from chromosome 18 with the immunoglobulin heavy chain joining region. In the t(14; 18) translocation bearing cell line SU-DHL-6, this results not only in an inappropriately high rate of bcl-2 transcription for a mature B cell, but also in two potentially critical point mutations. To determine the relative importance of these mutations, we searched for their presence in DNA from the involved lymph nodes of 12 patients with t(14; 18) follicular lymphoma. bcl-2 genomic sequences were specifically amplified by the polymerase chain reaction technique and then directly sequenced. None of the 12 samples analysed revealed the codon 7 or codon 129 mutation detected in SU-DHL-6. We conclude that abnormal expression of bcl-2 rather than structural alterations at codon 7 or 129 play an important role in the disordered growth and differentiation of follicular B-cell lymphoma.


Asunto(s)
Linfoma/genética , Proteínas Tirosina Quinasas , Proteínas Proto-Oncogénicas/genética , Proto-Oncogenes , Linfocitos B , ADN de Neoplasias/análisis , Amplificación de Genes , Expresión Génica , Humanos , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas c-bcr , Translocación Genética
8.
J Clin Oncol ; 5(5): 735-41, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-3494818

RESUMEN

Immunoglobulin (Ig) heavy (H) and light (L) chain gene rearrangements were used as molecular markers of clonal evolution and minimal residual disease in B cell precursor acute lymphoblastic leukemia (ALL). All leukemic episodes within individual patients shared at least one identical Ig rearrangement and thus arose from a common clonal progenitor cell. Nine of 11 patients displayed completely identical patterns between leukemic episodes, while two of 11 patients demonstrated genetic progression between diagnosis and relapse as evidenced by additional rearrangements. These genetic changes marked the emergence of leukemic subclones. Ig gene rearrangements were also used as sensitive markers to identify clonal cell populations in ALL patients following induction or reinduction therapy and to search for residual bone marrow disease in patients in clinical remission or with isolated extramedullary relapse. DNA rearrangements provide tumor-specific markers to follow the genetic variation of ALL and may facilitate the early detection of recurrent disease.


Asunto(s)
Genes , Inmunoglobulinas/genética , Leucemia Linfoide/patología , Linfocitos B/ultraestructura , Células de la Médula Ósea , Células Clonales , ADN de Neoplasias/análisis , Marcadores Genéticos , Humanos , Leucemia Linfoide/genética , Células Madre/ultraestructura
9.
Mol Immunol ; 23(7): 725-32, 1986 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-3099178

RESUMEN

A patient (BW) was studied with Mu heavy chain disease (mu HCD) in whom a leukemic B-cell clone secreted a shortened monoclonal mu chain without associated light chain. The cells did, however, produce a normal-sized kappa light chain that was detected as urinary Bence-Jones protein. The cytoplasmic and secreted monomeric mu chain had an approximate mol. wt of 58,000. Radiochemical sequence analysis of the biosynthetically labelled mu chain revealed a protein that lacked the entire variable region. The sequence initiated at amino acid position 5 within the first constant region domain (CH1) of C mu. The primary in vitro translation product, the cytoplasmic and secreted proteins were all similarly truncated, thereby excluding extensive postsynthetic degradation. The mu RNA, that directed the synthesis of the truncated mu protein, was about 350 bp smaller than the normal mu RNA. Furthermore, by primer extension analysis it was possible to localize this deletion in the mu RNA to a region 5' of CH1. Thus, a defect at the level of Ig gene structure/assembly that deletes coding information or results in aberrant RNA processing must be responsible for the truncated mu HCD protein BW.


Asunto(s)
Enfermedad de las Cadenas Pesadas/genética , Cadenas mu de Inmunoglobulina , Secuencia de Aminoácidos , Proteína de Bence Jones/orina , Electroforesis en Gel de Poliacrilamida , Femenino , Humanos , Inmunoelectroforesis , Cadenas mu de Inmunoglobulina/biosíntesis , Cadenas mu de Inmunoglobulina/genética , Biosíntesis de Proteínas , ARN Mensajero/análisis
10.
Appl Biochem Biotechnol ; 96(1-3): 125-33, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11783879

RESUMEN

Molecular designing of low-band-gap electrically conducting polymers continues to be a major challenge of the field of electrically conducting polymers. Such polymers are expected to show not only good intrinsic conductivity but also possibly a good transparency in the visible spectrum for their use as infrared sensors/detectors. Low-band-gap polymers can also be of great interest as new polymeric materials for nonlinear optics. Various routes presently followed to achieve this designing with special reference to the donor-acceptor polymers and important results obtained with this route are briefly reviewed.


Asunto(s)
Biotecnología/métodos , Ciclopentanos/química , Conductividad Eléctrica , Polímeros , Modelos Químicos , Modelos Estadísticos
11.
Appl Biochem Biotechnol ; 96(1-3): 135-43, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11783881

RESUMEN

Various quasi-one-dimensional superlattices (copolymers) (AmBn)x of two novel donor-acceptor polymers PPDCF ([A]x) and PPDCN ([B]x) based on poly(cyclopentadienylene) (PPD) and belonging to the class of type II staggered superlattices were investigated using a negative factor counting method in the tight-binding approximation. Both PPDCF and PPDCN consist of a bicyclopentadienylene unit bridged by an electron-accepting group >C=CF2 in PPDCF and >C=C(CN)2 in PPDCN. The trends in the electronic structures and conduction properties of the copolymers (AmBn)x as a function of the block sizes m and n, arrangement of the units (periodic or random) in the copolymer chain, and length of the copolymer chain are discussed.


Asunto(s)
Ciclopentanos/química , Conductividad Eléctrica , Polímeros/química , Biotecnología , Modelos Químicos
13.
J Pharm Biomed Anal ; 53(3): 287-94, 2010 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-20399586

RESUMEN

Nelfinavir mesylate is the first nonpeptidic protease inhibitor available in pediatric formulation. In the present paper the stability of nelfinavir mesylate under different stress conditions is evaluated using Fourier transform infrared spectroscopy. The drug is subjected to thermal degradation, photodegradation, acid hydrolysis, base hydrolysis and oxidation as per ICH guidelines. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and high performance liquid chromatography (HPLC) are carried out to support the implementation of infrared spectroscopy for the stability studies of nelfinavir mesylate. Significant changes are observed in the IR spectra collected after exposing the drug to thermal radiations, acid and base hydrolysis and oxidative degradation. No change is observed in the spectra of the drug after exposing it to sunlight indicating the good photostability of nelfinavir mesylate. The results of infrared spectroscopy agree well with that of other complementary techniques as DSC, TGA, XRD and HPLC.


Asunto(s)
Inhibidores de la Proteasa del VIH/química , Nelfinavir/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Rastreo Diferencial de Calorimetría , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Fotólisis , Termogravimetría , Difracción de Rayos X
14.
Drug Test Anal ; 1(5): 240-4, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-20355202

RESUMEN

5-Fluorouracil is one of the oldest chemotherapy drugs and it has been in use for decades. It is an active medicine against several types of cancer and effectively blocks the replication of DNA viruses. The present study assessed the potential of diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy to determine the thermal stability of 5-fluorouracil. Infrared spectra of the drug before and after exposure to thermal radiation at different temperatures were collected in diffuse reflectance mode using a Fourier transform infrared (FTIR) spectrophotometer. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis were carried out simultaneously to confirm and support the results of infrared spectroscopy. The DRIFT spectra reveal that the drug shows good thermal stability up to 275 degrees C and undergoes complete thermal breakdown at about 285 degrees C. The results of DSC and XRD analysis also give the same information, which support the implementation of diffuse reflectance infrared spectroscopy for the determination of thermal stability of 5-fluorouracil.


Asunto(s)
Antimetabolitos Antineoplásicos/química , Fluorouracilo/química , Rastreo Diferencial de Calorimetría , Estabilidad de Medicamentos , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
15.
Drug Test Anal ; 1(6): 275-8, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20355206

RESUMEN

The determination of moisture content in pharmaceuticals is very important as moisture is mainly responsible for the degradation of drugs. Degraded drugs have reduced efficacy and could be hazardous. The objective of the present work is to replace the Karl Fischer (KF) titration method used for moisture analysis with a method that is rapid, involves no toxic materials and is more effective. Diffuse reflectance infrared (IR) spectroscopy, which is explored as a potential alternative to various approaches, is investigated for moisture analysis in 5-fluorouracil, an anticancer drug. A total of 150 samples with varying moisture content were prepared in laboratory by exposing the drug at different relative humidities, for different time intervals. Infrared spectra of these samples were collected with a Fourier transform infrared (FTIR) spectrophotometer using a diffuse reflectance accessory. Reference moisture values were obtained using the Karl Fischer titration method. A number of calibration models were developed using the partial least squares (PLS) regression method. A good correlation was obtained between predicted IR values and reference values in the calibration and validation set. The derived calibration curve was used to predict moisture content in unknown samples. The results show that IR spectroscopy can be used successfully for the determination of moisture content in the pharmaceutical industry.


Asunto(s)
Antimetabolitos Antineoplásicos/análisis , Fluorouracilo/análisis , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Antimetabolitos Antineoplásicos/química , Fluorouracilo/química , Humedad , Análisis de los Mínimos Cuadrados , Factores de Tiempo , Volumetría , Agua/química
16.
Pak J Biol Sci ; 10(6): 941-5, 2007 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-19069894

RESUMEN

PCR-RFLP was used to genotype 87 Sarabi native cattle of north-western Iran for A and B alleles of kappa casein gene. A 350 bp length of exon 4 and intron 4 was amplified and digested with HinfI endonuclease. Samples were loaded on agarose gel (2%) and genotyped under UV light. Allele frequency of desirable B allele was 0.57. Stochastic simulation was used to generate milk yield trait for a population of 4950 females and 50 males for 15 overlapping generations. Population parameters included 1100 and 436 kg for average milk yield and phenotypic deviation, respectively; with heritability of 0.27. Additive and dominance effects of Kappa Casein gene were considered as 187.63 and 50.37 kg, respectively. Two methods were considered for selection of males based on the first phenotypic record of their dams (PAS) or molecular information of each male, individually (GAS). Females were always selected on their first phenotypic record. Although, there was a significant difference between polygenic and major gene genetic response between two methods after the 5th generations, but there was no significant difference for the sum of polygenic and major gene response. After 15 generations of selection there was no significant difference between inbreeding coefficient under two methods. Selection plan for males based on one single major gene had no advantage over the conventional selection based on dam record in native Sarabi breed.


Asunto(s)
Cruzamiento/métodos , Caseínas/genética , Bovinos/genética , Leche/fisiología , Selección Genética , Animales , Bovinos/fisiología , Simulación por Computador , Frecuencia de los Genes , Genotipo , Polimorfismo de Longitud del Fragmento de Restricción/genética , Procesos Estocásticos
17.
Br J Haematol ; 63(2): 321-9, 1986 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3087408

RESUMEN

We report a case of acute leukaemia with the t(4;11) chromosomal translocation which, at initial diagnosis, had L-1 lymphoblasts that were positive for terminal deoxynucleotidyl transferase (TdT) and HLA-DR but negative for myeloid cytochemical markers. At last relapse the patient had mostly monocytoid blasts which were not TdT negative but were positive for HLA-DR, weakly positive for Sudan Black B (SB), periodic acid Schiff's (PAS), naphthol AS-D acetate esterase (NSE), chloroacetate esterase (CAE) and negative for acid phosphatase (AP) and nitroblue tetrazolium (NBT) reduction. Treatment with 12-o-tetradecanoylphorbol-13-acetate (TPA) in vitro induced differentiation to macrophage-like cells that were strongly positive for SB, PAS, NSE, AP, CAE and NBT reduction, indicating a latent monocyte-like phenotype. Thus the leukaemic cell clone or a precursor clone with the t(4;11) translocation manifested a lymphoid phenotype at initial diagnosis and a monocytoid phenotype at relapse. Immunoglobulin gene analysis of the monocytoid relapse blasts revealed rearrangements of the heavy chain gene alleles and germline light chain genes. Thus, the leukaemia clone with the t(4;11) chromosomal translocation could be a bipotential cell with heavy chain gene rearrangements occurring in a primitive cell which may retain the ability to differentiate along the myeloid-monocytoid lineage in response to the appropriate stimulus. Alternatively, these characteristics may result from a transformation associated event.


Asunto(s)
Cadenas Pesadas de Inmunoglobulina/genética , Leucemia Linfoide/genética , Translocación Genética , Diferenciación Celular/efectos de los fármacos , Antígenos HLA-DR , Antígenos de Histocompatibilidad Clase II/análisis , Humanos , Lactante , Leucemia Linfoide/enzimología , Leucemia Linfoide/inmunología , Masculino , Acetato de Tetradecanoilforbol/farmacología
18.
J Immunol ; 141(5): 1738-44, 1988 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-3137264

RESUMEN

The lack of covalently associated L chains features H chain disease proteins produced in some human B cell lymphoproliferative disorders. We cloned and characterized the single rearranged kappa L chain gene from the leukemic lymphocytes of a patient (RIV) affected with gamma 1 H chain disease, to determine the molecular basis for absent L chain. This kappa allele had undergone an effective V-J rearrangement. Extensive somatic mutation focused about the V-J region created a sequence that was only 75% homologous to its germ-line counterpart. Altered acceptor (V kappa) and donor (J kappa) splice sites resulted in an aberrant splice between the leader and C kappa exons and a truncated 850-bp kappa mRNA. RIV leukemic cells as well as myeloma cells transfected with the RIV kappa gene synthesized a truncated protein. Simultaneous defects in H and L chains genes may reflect a hypermutational mechanism for Ig genes in B cells.


Asunto(s)
Genes de Inmunoglobulinas , Enfermedad de las Cadenas Pesadas/genética , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas gamma de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/genética , Mutación , Empalme del ARN , Secuencia de Aminoácidos , Secuencia de Bases , Enfermedad de las Cadenas Pesadas/inmunología , Humanos , Regiones Constantes de Inmunoglobulina/genética , Región de Unión de la Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Cadenas gamma de Inmunoglobulina/biosíntesis , Cadenas kappa de Inmunoglobulina/biosíntesis , Leucemia/genética , Leucemia/inmunología , Linfocitos/metabolismo , Datos de Secuencia Molecular , Señales de Clasificación de Proteína/genética , ARN Mensajero/aislamiento & purificación
19.
Nature ; 316(6025): 260-2, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3927169

RESUMEN

Human immunoglobulin light-chain genes become rearranged in an ordered fashion during pre-B-cell development such that rearrangement generally occurs in kappa genes before lambda genes (refs 1,2). This ordered process includes an unanticipated deletion of the constant kappa (C kappa) gene and kappa enhancer sequence which precedes lambda rearrangement, and the site of this deletional recombination was located 3' to the joining (J kappa) segments in 75% of cases studied. We have now characterized the recombinational element responsible for this event on three separate alleles and found them to be identical. This kappa-deleting element recombined site-specifically with a palindromic signal (CACAGTG) located in the J kappa-C kappa intron. All losses of C kappa genes in other human B cells were mediated by this determinant, including the 25% of instances when this element recombined with sequences 5' to J kappa. In contrast, the kappa-deleting element remained in its germline form on all successful kappa-producing alleles. Moreover, kappa loss is an evolutionarily conserved event, as the kappa-deleting element appears to be the human homologue of the murine RS sequence. Our results suggest that this element may help ensure isotypic and allelic exclusion of light chains and may be involved in the ordered use of human light-chain genes.


Asunto(s)
Linfocitos B/inmunología , Deleción Cromosómica , Cadenas Ligeras de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/genética , Elementos de Facilitación Genéticos , Humanos , Regiones Constantes de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Cadenas lambda de Inmunoglobulina/genética
20.
Ann Intern Med ; 102(4): 497-510, 1985 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3919627

RESUMEN

Immunoglobulin genes responsible for individual antibodies are organized as discontinuous DNA segments in their germline form. As an uncommitted stem cell develops into an antibody-synthesizing plasma cell, rearrangements of these immunoglobulin gene segments serve to activate the genes and to generate the virtually unlimited capacity to synthesize antibodies that recognize potential antigens. The analysis of immunoglobulin gene structure and arrangement has been of immense value in the study of human lymphoid neoplasms. Recombinant DNA technology involving analysis of immunoglobulin gene arrangement has been used to classify neoplasms of previously uncertain lineage, aid in the diagnosis of neoplasms of the B-cell series, and define the state of differentiation of neoplastic B-cell precursors. Furthermore, the demonstration of translocation of a particular transforming gene, the c-myc oncogene, into the immunoglobulin gene locus in Burkitt's lymphoma has provided a major insight into the cause of malignant transformation of these lymphoid cells.


Asunto(s)
Linfoma de Burkitt/genética , Genes , Inmunoglobulinas/genética , Leucemia/genética , Oncogenes , Alelos , Animales , Diversidad de Anticuerpos , Antígenos de Neoplasias/genética , Antígenos de Superficie/genética , Linfocitos B/clasificación , Linfocitos B/inmunología , Linfoma de Burkitt/inmunología , Transformación Celular Neoplásica , Mapeo Cromosómico , ADN de Neoplasias/genética , Marcadores Genéticos , Humanos , Cadenas Ligeras de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Leucemia/inmunología , Leucemia de Células Pilosas/genética , Leucemia Linfoide/genética , Leucemia Mieloide Aguda/genética , Fenotipo , Translocación Genética
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