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1.
Mol Cell Biol ; 25(20): 9127-37, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16199888

RESUMO

The yeast SPT10 gene encodes a putative histone acetyltransferase (HAT) implicated as a global transcription regulator acting through basal promoters. Here we address the mechanism of this global regulation. Although microarray analysis confirmed that Spt10p is a global regulator, Spt10p was not detected at any of the most strongly affected genes in vivo. In contrast, the presence of Spt10p at the core histone gene promoters in vivo was confirmed. Since Spt10p activates the core histone genes, a shortage of histones could occur in spt10Delta cells, resulting in defective chromatin structure and a consequent activation of basal promoters. Consistent with this hypothesis, the spt10Delta phenotype can be rescued by extra copies of the histone genes and chromatin is poorly assembled in spt10Delta cells, as shown by irregular nucleosome spacing and reduced negative supercoiling of the endogenous 2mum plasmid. Furthermore, Spt10p binds specifically and highly cooperatively to pairs of upstream activating sequence elements in the core histone promoters [consensus sequence, (G/A)TTCCN(6)TTCNC], consistent with a direct role in histone gene regulation. No other high-affinity sites are predicted in the yeast genome. Thus, Spt10p is a sequence-specific activator of the histone genes, possessing a DNA-binding domain fused to a likely HAT domain.


Assuntos
Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Bases , Sítios de Ligação/genética , Cromatina/genética , DNA Fúngico/genética , DNA Fúngico/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Histona Acetiltransferases , Histonas/genética , Dados de Sequência Molecular , Fenótipo , Regiões Promotoras Genéticas , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética
2.
Case Rep Oncol ; 10(2): 489-492, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28690522

RESUMO

Small cell carcinoma of the urinary tract is an extremely rare disease with very few cases reported in the literature. Its clinical course is aggressive, and the prognosis is poor. Here, we present a case of metastatic extrapulmonary small cell carcinoma of the upper urinary tract in a 74-year-old African-American male. He initially presented with gross hematuria, 20-pound weight loss, and abdominal pain for 2 months. CT imaging showed a 14.0 × 7.0 × 16.0 cm retroperitoneal mass within the left renal fossa; biopsy revealed a carcinoma which was positive for synaptophysin and chromogranin. The patient also had detectable neuroendocrine cells in his urine cytology, confirming the diagnosis of small cell carcinoma. He was treated with carboplatin and etoposide as extrapolated from the treatment of its pulmonary counterpart. Due to the rarity of urinary tract small cell carcinoma, no randomized studies exist to guide therapy or management.

3.
Case Rep Oncol Med ; 2017: 7834702, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28373919

RESUMO

Surgery is the only chance for cure in pancreatic ductal adenocarcinoma. In unresectable, locally advanced pancreatic cancer (LAPC), the National Comprehensive Cancer Network (NCCN) suggests chemotherapy and consideration for radiation in cases of unresectable LAPC. Here we present a rare case of unresectable LAPC with a complete histopathological response after chemoradiation followed by surgical resection. A 54-year-old female presented to our clinic in December 2013 with complaints of abdominal pain and 30-pound weight loss. An MRI demonstrated a mass in the pancreatic body measuring 6.2 × 3.2 cm; biopsy revealed proven ductal adenocarcinoma. Due to splenic vein/artery and contiguous celiac artery encasement, she was deemed surgically unresectable. She was started on FOLFIRINOX therapy (three cycles), intensity modulated radiation to a dose of 54 Gy in 30 fractions concurrent with capecitabine, followed by FOLFIRI, and finally XELIRI. After 8 cycles of ongoing XELIRI completed in March 2015, restaging showed a remarkable decrease in tumor size, along with PET-CT revealing no FDG-avid uptake. She was reevaluated by surgery and taken for definitive resection. Histopathological evaluation demonstrated a complete R0 resection and no residual tumor. Based on this patient and literature review, this strategy demonstrates potential efficacy of neoadjuvant chemoradiation with prolonged chemotherapy, followed by surgery, which may improve outcomes in patients deemed previously unresectable.

4.
Clin Rheumatol ; 34(10): 1813-6, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24810700

RESUMO

Muscle pain and weakness in a rheumatoid arthritis (RA) patient has a broad differential, and myositis should be considered early in the disease course as serious limb and life-threatening sequelae may occur. A 55-year-old woman with a past medical history of methotrexate-controlled RA presented with right leg pain for 4 days. The patient suffered sensory loss in the right foot and decreased strength in the toes. Lab tests revealed elevated creatine kinase, ESR, and anti-rheumatoid factor antibody titers. CT scan revealed myositis of posterior compartment muscles. Progressive edema, pain, and neuromuscular deficits persisted despite steroid and antibiotic therapy, so the patient was taken for urgent fasciotomy for acute compartment syndrome. The muscle biopsy showed diffuse mononuclear cell infiltration as well as perivascular and perineural involvement consistent with rheumatoid myositis (RM). The patient did well post-op on a prednisone taper. This case underlines the systemic nature of RA and exemplifies the severity of inflammation that may lead to grave consequences such as compartment syndrome. The histopathology is diagnostic when there is evidence of mononuclear cell infiltration; however, this is not entirely specific. Early, aggressive therapy with immunosuppressives is warranted in such patients. RM has not, to our knowledge, been recorded to cause acute compartment syndrome. Clinicians should be aware of this uncommon manifestation of RA keeping the various presentations of rheumatoid disease in mind when faced with these patients.


Assuntos
Artrite Reumatoide/complicações , Síndromes Compartimentais/complicações , Miosite/complicações , Biópsia , Sedimentação Sanguínea , Síndromes Compartimentais/cirurgia , Creatina Quinase/metabolismo , Edema/patologia , Feminino , Humanos , Imunossupressores/química , Inflamação , Perna (Membro)/patologia , Leucócitos Mononucleares/citologia , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Atrofia Muscular , Miosite/patologia , Miosite/cirurgia , Prednisona/uso terapêutico , Fator Reumatoide/metabolismo
5.
BMJ Case Rep ; 20142014 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-25008332

RESUMO

Toxic epidermal necrolysis (TEN) is a rare but serious dermatological emergency characterised by diffuse exfoliation of the skin and mucous membranes due to immune mediated destruction of the epidermis which can lead to sepsis and respiratory distress. Trimethoprim-sulfamethoxazole is a widely used antibiotic which can rarely lead to TEN. Early diagnosis and aggressive medical care is essential for the reduction of high morbidity and mortality associated with this disease. We present a case of successfully recovered TEN due to trimethoprim-sulfamethoxazole in a 62-year-old woman.


Assuntos
Antibacterianos/efeitos adversos , Hidratação , Síndrome de Stevens-Johnson/diagnóstico , Combinação Trimetoprima e Sulfametoxazol/efeitos adversos , Infecções Urinárias/tratamento farmacológico , Cicatrização , Antibacterianos/administração & dosagem , Antibioticoprofilaxia/métodos , Relação Dose-Resposta a Droga , Diagnóstico Precoce , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Síndrome de Stevens-Johnson/patologia , Síndrome de Stevens-Johnson/terapia , Resultado do Tratamento , Combinação Trimetoprima e Sulfametoxazol/administração & dosagem
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