RESUMEN
The spontaneous leukemia (SL) viruses are ecotropic lymphomagenic viruses isolated from AKR spontaneous lymphomas. These viruses are produced stably by continuous cell lines from spontaneous lymphomas and by a cell line derived from the bone marrow stroma of an AKR mouse neonatally inoculated with an SL virus. All cell lines cloned from the parent lymphoma cell lines consistently produce SL viruses. These viruses can be passaged in vivo and maintain their leukemogenic properties. Cloned isolates of SL viruses accelerate lymphoma in AKR mice and induce thymic lymphoma in mice of other strains. Thus their lymphomagenic properties are conclusively shown. In a study with the use of a sensitive host range assay, xenotropic and/or dual-host range viruses are consistently found in spontaneous lymphoma and cell lines derived from them. However, viruses able to replicate in mink lung cells are not expressed in SL virus-induced lymphomas or their derived cell lines.
Asunto(s)
Virus de la Leucemia Murina/patogenicidad , Linfoma/microbiología , Animales , Línea Celular , Ensayo de Unidades Formadoras de Colonias , Leucemia Experimental/microbiología , Ratones , Ratones Endogámicos AKR , Ratones Endogámicos C3H , Trasplante de Neoplasias , Neoplasias del Timo/microbiologíaRESUMEN
A new technique for characterizing somatic mutations in very small samples of cellularly heterogeneous human cancer tissue was developed and tested using mutations in the p53 gene in breast carcinomas as a model system. The technique combines touch preparation of specimens to obtain homogeneous clusters of carcinoma cells free of normal cells with a nested pair of polymerase chain reaction (PCR) amplifications of DNA to increase the amount of target gene sequence sufficiently to permit direct sequencing of the p53 gene. Touch preparations of fresh or previously frozen tissue from human adenocarcinomas derived from several organs were stained, and clusters of 10-50 malignant cells were transferred by pipette into microfuge tubes for PCR amplification. Exons 5-9 of the p53 gene, which contain the major mutational hot spots associated with most human cancers, were sequenced by the following steps: 1) two rounds of PCR amplification using DNA Taq polymerase and two sets of oligonucleotide primers, the second set being nested within the segment amplified by the first set and having attached T7 and SP6 phage promoter sequences, 2) transcription of the amplified DNA sequences with T7 and SP6 RNA polymerases, and 3) dideoxy sequencing of single-stranded RNA transcripts with reverse transcriptase and with additional oligonucleotide primers to achieve specificity for this unique region of the genome. The utility of this approach is illustrated by our success in detecting and analyzing point mutations in cell clusters from four of 11 primary adenocarcinomas of the human breast.
Asunto(s)
Adenocarcinoma/genética , Neoplasias de la Mama/genética , Genes p53/genética , Mutación/genética , Secuencia de Bases , Eosina Amarillenta-(YS) , Femenino , Hematoxilina , Humanos , Azul de Metileno , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Cloruro de Tolonio , Células Tumorales CultivadasRESUMEN
The interaction of the immunosuppressive complex cyclosporin A-cyclophilin (CsA-CyP) with the Ca2+/calmodulin-dependent protein phosphatase calcineurin is investigated using a recombinant form of the A subunit of calcineurin (rCNA). Only in the presence of purified calcineurin B (CNB) does rCNA show the response of native calcineurin, i.e. 50% inhibition of rCNA phosphatase activity at 6 nM human cyclophilin B and 0.6 microM human cyclophilin A using [32P]casein as substrate, yet stimulation of activity with p-nitrophenyl phosphate as substrate. This study demonstrates that the B subunit is necessary to confer sensitivity of calcineurin to CsA-CyP.
Asunto(s)
Isomerasas de Aminoácido/farmacología , Proteínas de Unión a Calmodulina/efectos de los fármacos , Proteínas Portadoras/farmacología , Ciclosporina/farmacología , Ciclosporinas/farmacología , Fosfoproteínas Fosfatasas/efectos de los fármacos , Calcineurina , Proteínas de Unión a Calmodulina/genética , Caseínas/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Nitrofenoles/metabolismo , Compuestos Organofosforados/metabolismo , Isomerasa de Peptidilprolil , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas Fosfatasas/metabolismo , Proteínas Recombinantes/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
PURPOSE: The results of therapy in 288 men with pathologic Stage C prostate cancer who underwent radical retropubic prostatectomy (RRP) were analyzed to determine the effects of adjuvant therapy. METHODS AND MATERIALS: Twenty-seven of the 288 patients received preoperative neoadjuvant hormonal therapy (leuprolide acetate). Postoperatively, 60 patients received adjuvant radiotherapy (RT) to the prostate bed. Follow-up ranged from 3 to 83 months (median = 32 months). Freedom from failure (FFF) was defined as maintaining a serum PSA level of < or = 0.3 ng/ml. RESULTS: The FFF was 61% at 3 years and 45% at 5 years for the entire group. The FFF following RRP plus RT was 75% at 3 years and 57% at 5 years as compared to 56% at 3 years and 40% at 5 years for RRP without RT (p=0.049). The FFF following RRP plus neoadjuvant hormonal therapy was 58% at 3 years and 40% at 5 years as compared to 60% at 3 years and 45% at 5 years following RRP without hormonal therapy (p=0.3). In patients without seminal vesicle (SV) invasion, the FFF was 81% at 3 years and 5 years for RRP plus RT as compared to 61% at 3 years and 50% at 5 years for RRP without RT (p=0.01). In patients with SV invasion, the FFF was 61% at 3 years and 36% at 5 years for RRP plus RT as compared to 44% at 3 years and 23% at 5 years for RRP without RT (p=0.23). The projected local control rate was 83% at 5 years for those with RRP alone as compared to 100% for RRP plus RT (p=0.02). Survival at 5 years was projected to be 92% and was not significantly altered by the administration of adjuvant therapies. CONCLUSIONS: Postoperative RT was associated with significantly improved local control and FFF rates, especially in patients with tumors which did not involve the seminal vesicles.
Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Leuprolida/uso terapéutico , Prostatectomía , Neoplasias de la Próstata/terapia , Anciano , Quimioterapia Adyuvante , Terapia Combinada , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Prostatectomía/métodos , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/cirugía , Radioterapia Adyuvante , Insuficiencia del TratamientoRESUMEN
This study reports experiments with thymic stromal remnants in AKR mice, a strain with a high natural incidence of thymic lymphoma. A method has been developed in which thymic stromal cells which survive a 4-week culture period, 1 week at 24 degrees C and 3 weeks at 37 degrees C are suitable for grafting. Most thymic lymphocytes die under these conditions. Stromal remnants were studied by culturing and grafting under the kidney capsule of 2-month-old syngeneic mice. Their in vitro morphology and virus production, their ability to reconstitute a new thymus from host progenitors and their eventual lymphoma development was evaluated. The stromal remnants were from: 1- and 3-month-old normal mice; 6-10-month-old normal mice; 21-28-day-old animals treated with the lymphomagenic virus, SL3-3, at 3 days of age. Our data show that thymic stromal function as measured by lymphoid reconstitution of thymic stromal grafts of AKR mice is not impaired with age or by the presence of oncogenic virus. Oncogenic viruses are found in the thymic stroma of old mice and in thymic stroma of young virus-treated mice. Oncogenic viruses are not found in thymic stroma of young normal mice. Lymphoma can develop in the grafted stromal remnants expressing lymphomagenic virus.
Asunto(s)
Ratones Endogámicos AKR/fisiología , Timo/microbiología , Replicación Viral , Animales , Linfoma/microbiología , Linfoma/patología , Ratones , ADN Polimerasa Dirigida por ARN/análisis , Timo/patología , Timo/trasplanteRESUMEN
An alternative localization technique or extracorporeal shock wave lithotripsy using devices that use fluoroscopic targeting is presented. Excretory urography during lithotripsy can provide valuable targeting information and the results of treatment in a manner that may prove useful in the treatment of urinary calculi.
Asunto(s)
Litotricia/métodos , Cálculos Urinarios/diagnóstico por imagen , Humanos , Cálculos Urinarios/terapia , Urografía/métodosRESUMEN
OBJECTIVES: To determine the personal characteristics, the mode of presentation, the duration of the delay in diagnosis, the number of misdiagnoses, the means to achieve diagnosis, and previous treatment provided for a group of men with interstitial cystitis (IC). METHODS: A chart review of 29 men diagnosed with IC at our facility from 1988 to 1996 was performed. Basic demographic data, historical information, laboratory findings, and endoscopic and biopsy results were tabulated. RESULTS: IC in this series of men was diagnosed at a mean age of 67.3 years. There was approximately a 4-year diagnostic lag between presentation and diagnosis. The most common prior erroneous diagnoses were prostatitis in 48% and benign prostatic hypertrophy (BPH) in 38% of the men. Ulcers were encountered cystoscopically in about 70% and biopsy specimens uniformly showed nonspecific chronic cystitis at the time of diagnosis. CONCLUSIONS: IC should be considered in the differential diagnosis of voiding disorders accompanied by irritative symptoms and pelvic pain in older men. The diagnosis should be especially considered in men who are refractory to the usual treatments for BPH and prostatitis. Cystoscopy and bladder distention under anesthesia provided the most useful objective information in our hands. Biopsy is useful to rule out inflammatory cancer but adds little to the diagnosis of IC.
Asunto(s)
Cistitis Intersticial/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Cistitis Intersticial/complicaciones , Diagnóstico Diferencial , Errores Diagnósticos , Humanos , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
OBJECTIVES: This retrospective study was undertaken to compare the efficacy of the Vest and direct vesicourethral anastomosis for radical prostatectomy. METHODS: Five hundred six patients who underwent consecutive radical prostatectomies at our institution were analyzed. Two hundred fifty-nine patients underwent vesicourethral anastomosis using the Vest technique and 247 underwent a direct suture anastomosis. The groups were analyzed relative to time until healing, the occurrence of anastomotic strictures, and the continence rate 1 year after surgery. RESULTS: Approximately twice as many patients who underwent the Vest procedure experienced delayed healing and 8.5% developed anastomotic strictures compared with 1.2% of the direct anastomosis group. The Vest group experienced slightly better urinary continence 1 year postoperatively. CONCLUSIONS: The Vest procedure is a reasonable alternative to direct anastomosis for radical prostatectomy and provides similar results. We suggest specific circumstances when the Vest anastomosis may be particularly useful.
Asunto(s)
Prostatectomía/métodos , Uretra/cirugía , Vejiga Urinaria/cirugía , Anciano , Anastomosis Quirúrgica , Humanos , Masculino , Estudios RetrospectivosRESUMEN
OBJECTIVES: This analysis was performed to define the level of serum prostate-specific antigen (PSA) measured with the Abbott IMx assay that indicates residual or progressive prostate cancer after radical retropubic prostatectomy (RRP). METHODS: Since March 1992, we have used the Abbott IMx assay to determine PSA levels. Between March 1992 and June 1994, 102 of those patients having RRPs were found to have pathologic Stage C prostate cancer. Fifty-one of these patients had at least one serum PSA measurement of 0.1 ng/mL or greater. Eight patients were excluded from the analysis because they received postoperative radiotherapy that might have influenced subsequent PSA levels. The remaining 43 patients are the subjects of this analysis and were evaluated to determine the "clinical threshold" or minimal serum PSA level after RRP indicative of progressive disease. Patients were followed for 6 to 36 months (median 23 months) from the date of the RRP. Failure was defined as a subsequent increase of PSA to greater than 0.3 ng/mL. Freedom from failure was determined using the Kaplan-Meier product limit method. RESULTS: Of the patients with at least one postoperative serum PSA level of 0.1 ng/mL, the subsequent freedom from failure was 80% at 23 months as compared with 13% in patients with at least one postoperative PSA level of 0.2 ng/mL (P = 0.003). CONCLUSIONS: Following RRP for pathologic Stage C prostate cancer, a solitary PSA level of 0.1 ng/mL (measured with the IMx assay) was followed by a progressive rise in PSA levels in only a minority of patients within the first 2 years after surgery. In contrast, the majority of patients with a postoperative PSA level of 0.2 ng/mL subsequently had progressively rising PSA levels. This indicates that a serum PSA level of 0.2 ng/mL is reflective of residual prostate cancer.
Asunto(s)
Antígeno Prostático Específico/sangre , Prostatectomía , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/cirugía , Anciano , Humanos , Masculino , Persona de Mediana Edad , Neoplasia Residual , Cuidados Posoperatorios , Prostatectomía/métodosRESUMEN
Lumbar spinal stenosis is a common problem in elderly patients. In its more advanced forms, it typically causes intractable leg pain, but many patients also manifest varying degrees of bladder dysfunction. The goal of lumbar decompressive laminectomy is relief of leg pain and paresthesias, yet some patients also achieve improvement in bladder function. This study prospectively investigated patients with lumbar spinal stenosis to determine whether laminectomy had any effect on urological function. Of the 20 patients in the study, 10 were men and 10 women (average age 70.9 years). All patients had severe lumbar stenosis affecting between two and four spinal segments, and all reported some degree of bladder dysfunction. Cystoscopy and urodynamic testing were completed preoperatively. A standard decompressive laminectomy was performed over the appropriate number of spinal segments. Urodynamic studies were repeated at 2 and 6 months postoperatively. At the 6-month follow-up review, bladder function was subjectively improved in 12 patients (60%) and unchanged in eight (40%). Postvoiding residual urine volume was the urodynamic factor most likely to be improved by laminectomy. In nine patients (45%), baseline postvoiding residual urine volume was elevated and all nine had improvement postoperatively. In the remaining 11 patients (55%), this urine volume was normal before and after surgery. Maximum urine flow rates also improved, but the results of cytometrography and electromyography, urine flow pattern, and bladder capacity were unchanged postoperatively. Cystoscopy detected previously undiagnosed malignancy of the lower urinary tract in two patients (10%). It is concluded that lumbar decompressive laminectomy can have a beneficial effect on bladder function in a significant number of patients with advanced lumbar spinal stenosis.
Asunto(s)
Laminectomía , Vértebras Lumbares/cirugía , Estenosis Espinal/cirugía , Vejiga Urinaria/fisiopatología , Anciano , Anciano de 80 o más Años , Cauda Equina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndromes de Compresión Nerviosa/etiología , Síndromes de Compresión Nerviosa/cirugía , Estudios Prospectivos , Estenosis Espinal/complicaciones , Vejiga Urinaria Neurogénica/etiología , Vejiga Urinaria Neurogénica/fisiopatología , UrodinámicaRESUMEN
The presence of stones during an otherwise uneventful pregnancy is a dramatic and potentially serious issue for the mother, the fetus, and the treating physicians alike. The incidence and predisposing factors are generally the same as in nonpregnant, sexually active, childbearing women. Unique metabolic effects in pregnancy such as hyperuricuria and hypercalciuria, changes in inhibitors of lithiasis formation, stasis, relative dehydration, and the presence of infection all have an impact on stone formation. The anatomic changes and physiologic hydronephrosis of pregnancy make the diagnosis and treatment more challenging. Presenting signs and symptoms include colic, flank pain, hematuria, urinary tract infection, irritative voiding, fever, premature onset or cessation of labor, and pre-eclampsia. The initial evaluation and treatment are again similar to those used for the nonpregnant population. The most appropriate first-line test is renal ultrasonography, which may, by itself, allow the diagnosis to be made and provide enough information for treatment. Radiographic studies, including an appropriately performed excretory urogram, give specific information as to size and location of the stones, location of the kidneys, and differential renal function and can be used safely, but the ionizing radiation risks should be considered. All forms of treatment with the exception of extracorporeal shock wave lithotripsy and some medical procedures are appropriate in the pregnant patient. Close coordination by the urologist, the obstetrician, the pediatrician, the anesthesiologist, and the radiologist is required for the appropriate care of these patients.
Asunto(s)
Complicaciones del Embarazo , Cálculos Urinarios , Diagnóstico por Imagen , Femenino , Humanos , Embarazo , Complicaciones del Embarazo/diagnóstico , Complicaciones del Embarazo/patología , Complicaciones del Embarazo/fisiopatología , Complicaciones del Embarazo/cirugía , Cálculos Urinarios/diagnóstico , Cálculos Urinarios/etiología , Cálculos Urinarios/patología , Cálculos Urinarios/fisiopatología , Cálculos Urinarios/cirugíaAsunto(s)
Sigmoidoscopía , Cálculos de la Vejiga Urinaria/terapia , Epispadias/cirugía , Femenino , Humanos , Ileostomía , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/terapia , Tomografía Computarizada por Rayos X , Cálculos de la Vejiga Urinaria/diagnóstico por imagenRESUMEN
Twenty-seven patients with synchronous (19 cases) or asynchronous (8 cases) bilateral renal cell carcinoma were treated and followed for as long as 20 years. Tumor grade and stage generally were more favorable in the former group, which is reflected in the higher surgical intervention rate. Nonsurgical treatment yielded poor results. The 5-year survival rate for patients with synchronous bilateral renal cell carcinoma (77.8 per cent) was significantly higher than that for patients with asynchronous lesions (37.5% per cent). Because of its different presentation and favorable prognosis when treated surgically synchronous bilateral renal cell cancer should be distinguished from the asynchronous form, with its dismal outcome. For the latter cases thorough long-term followup may make early surgical intervention feasible, and thus, improve patient survival.
Asunto(s)
Adenocarcinoma/mortalidad , Neoplasias Renales/mortalidad , Neoplasias Primarias Múltiples/mortalidad , Adenocarcinoma/cirugía , Adulto , Anciano , Femenino , Humanos , Neoplasias Renales/cirugía , Masculino , Persona de Mediana Edad , Nefrectomía , Pronóstico , Factores de TiempoRESUMEN
The records of 108 patients presenting with leukoplakia of the urinary tract during the last 35 years were reviewed to define the natural history of this disease, with emphasis upon its association with urothelial cancer. Of the 108 patients 24 had upper urinary tract, 78 bladder and 10 urethral leukoplakia (1 with renal and bladder involvement, 3 with bladder and urethral involvement, and 1 with ureteral and renal involvement). Presenting complaints were primarily irritative. To date, 41 patients (37 per cent) have had associated carcinoma of the urothelium: 23 (21 per cent) presented with a concomitant or previous carcinoma and 18 of 85 (21 per cent) presenting without a concomitant or previous neoplasm have had documented progression to cancer. These figures support the concept that leukoplakia is a premalignant disease and that patients with this diagnosis deserve careful and frequent followup.
Asunto(s)
Leucoplasia/patología , Lesiones Precancerosas/patología , Neoplasias Uretrales/patología , Neoplasias de la Vejiga Urinaria/patología , Anciano , Carcinoma de Células Escamosas/patología , Carcinoma de Células Transicionales/patología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Characterization of the viruses produced by the spontaneous T lymphoma cell line SL3 is presented. Using supernatant fluids or direct co-cultivation of cells, the SL3 cell line was found to produce replication-defective viruses in excess of replication-competent viruses. The replication-competent viruses released were predominantly those negative in the XC plaque assay (XC-); XC+ viruses represented a minor population. However, when the SL3-derived viruses were passed in mouse embryo fibroblasts, XC- viruses were rarely recovered, and XC+ viruses were readily isolated. These viruses were all ecotropic and lymphomagenic. Viruses with dual host range and non-oncogenic ecotropic viruses were not isolated from the lymphoma cells. Two replication-defective viruses from SL3 cells were studied. Both could be rescued by non-oncogenic retroviruses and were then lymphomagenic. One defective virus appeared related to XC+ viruses. In these studies, the XC+ and XC- viruses appeared to represent two different interference classes using separate cell receptors. Taken together, these experiments show that the SL3 T lymphoma cells replicate a variety of viruses most of which are lymphomagenic. Virus replication and/or virus integration may be the means of maintaining the malignant phenotype of these T lymphoma cells.
Asunto(s)
Linfoma/microbiología , Retroviridae/aislamiento & purificación , Neoplasias del Timo/microbiología , Animales , Replicación del ADN , Virus Defectuosos/aislamiento & purificación , Productos del Gen gag , Genes Virales , Ratones , Ratones Endogámicos AKR , Retroviridae/genética , Linfocitos T/microbiología , Proteínas Virales/análisis , Replicación ViralRESUMEN
Vacuolar-H(+)-ATPase (V-H-ATPase) is a large multimeric protein composed of at least 12 distinct subunits. The 16-kDa hydrophobic proteolipid subunit (ATP6V0C; ATPase, H(+ )transporting, lysosomal 16 kDa, V0 subunit C) plays a central role in H(+) transport across cellular membranes. We have mapped three ATP6V0C genes (Atp6v0c, Atp6v0c-ps1 and Atp6voc-ps2) in the murine genome. Atp6v0c-ps1 and Atp6v0c-ps2 map to Chromosomes 7 and 6, respectively. Atp6v0c maps to Chromosome 17, closely linked to the Tsc2 locus and D17Mit55. This region of Chromosome 17 in mouse is homologous with chromosome 16 in human where the ATP6V0C gene is localized.
Asunto(s)
ATPasas de Translocación de Protón Vacuolares/genética , Animales , Secuencia de Bases , Mapeo Cromosómico , ADN Complementario/genética , Genoma , Humanos , Ratones , Ratones Endogámicos C57BL , Peso Molecular , Muridae , Subunidades de Proteína , Especificidad de la Especie , ATPasas de Translocación de Protón Vacuolares/químicaRESUMEN
The Ca(2+)- and calmodulin-dependent protein phosphatase calcineurin is inhibited by the immunosuppressant drug cyclosporin A in the presence of cyclophilin A or B. Of the two isoforms, cyclophilin B is more potent by a factor of 2-5 when either the phosphoprotein [32P]casein or the [32P]phosphoserine [Ser(32P)] form of the 19-residue bovine cardiac cAMP-dependent protein kinase regulatory subunit peptide RII, [Ser(32P)15]RII, is used as substrate. With [Ser(32P15]RII as substrate, the concentrations of the cyclosporin A.cyclophilin A and cyclosporin A.cyclophilin B complexes, which cause 50% inhibition of calcineurin activity, are 120 and 50 nM, respectively. Lowering the concentration of calcineurin 80% with [32P]casein as substrate lowered the apparent inhibition constant for each complex even further; 50% inhibition of calcineurin was observed at 40 nM for cyclosporin A.cyclophilin A, whereas it was less than 10 nM for cyclosporin A.cyclophilin B. In all inhibition assays with [32P]casein or [Ser(32P)15]RII, the concentration of calcineurin required for measurable phosphatase activity is such that these complexes behave as tight-binding inhibitors of calcineurin, and steady-state kinetics cannot be used to assess inhibition patterns or Ki values. Limited trypsinization of calcineurin produces a fragment that is still inhibited, indicating that the interaction of cyclosporin.cyclophilin with calcineurin does not require either calmodulin or Ca2+.
Asunto(s)
Isomerasas de Aminoácido/farmacología , Proteínas de Unión a Calmodulina/antagonistas & inhibidores , Proteínas Portadoras/farmacología , Ciclosporina/farmacología , Fosfoproteínas Fosfatasas/antagonistas & inhibidores , Isomerasas de Aminoácido/metabolismo , Animales , Calcineurina , Proteínas de Unión a Calmodulina/química , Proteínas de Unión a Calmodulina/metabolismo , Proteínas Portadoras/metabolismo , Bovinos , Ciclosporina/metabolismo , Técnicas In Vitro , Cinética , Sustancias Macromoleculares , Isomerasa de Peptidilprolil , Fosfoproteínas Fosfatasas/química , Fosfoproteínas Fosfatasas/metabolismo , Unión Proteica , Proteínas Recombinantes , Relación Estructura-Actividad , Tripsina/farmacologíaRESUMEN
Epigenetics is the alteration of phenotype without affecting the genotype. An underlying molecular mechanism of epigenetics is the changes of chromatin structure by covalent histone modifications and nucleosome reorganization. In the yeast, Saccharomyces cerevisiae, two of the most well-studied macromolecular complexes that perform these epigenetic changes are the ATP-dependent Swi/Snf chromatin-remodelling complex and the SAGA histone acetyltransferase complex. To understand fully the mechanism by which these large protein complexes perform their functions in the cell, it is crucial that all the subunits of these complexes are identified. In an attempt to identify new subunits associated with SAGA and Swi/Snf, we used tandem affinity purification, followed by a multidimensional protein identification technology to analyse the subunit composition. Our analysis identified two novel proteins, one associated with SAGA, YPL047W (Sgf11), and another associated with Swi/Snf, Rtt102.