RESUMO
OBJECTIVE: Childhood dermatomyositis (DM) is often a chronic disease, lasting many years. It has traditionally been treated with long-term corticosteroid therapy; side effects are often seen. For more than a decade, methotrexate (MTX) has been safely used for the treatment of juvenile arthritis. Here, we report use of MTX as first-line therapy for DM, along with aggressively tapered corticosteroids, in an attempt to reduce treatment-related side effects. METHODS: We studied an inception cohort of 31 children with DM who were rigorously followed up in our myositis clinic, and compared them with a control group of 22 patients with incident cases of juvenile DM who received treatment just before we instituted a policy of first-line therapy with MTX. The mean starting dosage of MTX in the study group was 15 mg/m(2)/week. RESULTS: Both groups had similar improvement in strength and physical function; however, the median time during which patients in the study group received corticosteroids was 10 months, compared with 27 months for controls (P < 0.0001). As a result, the cumulative prednisone dose in the study group was approximately half that in the control group (7,574 mg versus 15,152 mg; P = 0.0006). The study group had greater height velocity during the first year of treatment and a smaller increase in the body mass index over the first 2 years. In the control group, the relative risk of cataracts developing was 1.95 (95% confidence interval 1.05-4.17). Side effects of MTX were rarely observed. CONCLUSION: Use of MTX in conjunction with an aggressively tapered course of prednisone may be as effective as traditional long-term corticosteroid therapy for children with DM, while decreasing the cumulative dose of corticosteroids.
Assuntos
Dermatomiosite/tratamento farmacológico , Glucocorticoides/uso terapêutico , Imunossupressores/uso terapêutico , Metotrexato/uso terapêutico , Prednisona/uso terapêutico , Dermatomiosite/fisiopatologia , Avaliação da Deficiência , Relação Dose-Resposta a Droga , Esquema de Medicação , Quimioterapia Combinada , Nível de Saúde , Humanos , Debilidade Muscular/tratamento farmacológico , Debilidade Muscular/fisiopatologia , Músculo Esquelético , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The genome of the model plant Arabidopsis thaliana has been sequenced by an international collaboration, The Arabidopsis Genome Initiative. Here we report the complete sequence of chromosome 5. This chromosome is 26 megabases long; it is the second largest Arabidopsis chromosome and represents 21% of the sequenced regions of the genome. The sequence of chromosomes 2 and 4 have been reported previously and that of chromosomes 1 and 3, together with an analysis of the complete genome sequence, are reported in this issue. Analysis of the sequence of chromosome 5 yields further insights into centromere structure and the sequence determinants of heterochromatin condensation. The 5,874 genes encoded on chromosome 5 reveal several new functions in plants, and the patterns of gene organization provide insights into the mechanisms and extent of genome evolution in plants.
Assuntos
Arabidopsis/genética , Genoma de Planta , Animais , Mapeamento Cromossômico , DNA de Plantas , Humanos , Proteínas de Plantas/genética , Análise de Sequência de DNARESUMO
OBJECTIVE: To examine the ability of a previously described set of criteria to predict poor functional outcome in a large, multicenter cohort of children with systemic-onset juvenile rheumatoid arthritis (JRA). METHODS: All children who were diagnosed with systemic-onset JRA since 1980 at the Hospital for Sick Children (Toronto), since 1983 at the Isaac Walton Killam Hospital for Children (Halifax), and since 1981 at the Children's Hospital of Eastern Ontario (Ottawa) were evaluated. Patients were included in the study if they had been evaluated clinically within 6 months of diagnosis and had been followed up for at least 2 years. Patients were divided into 4 cohorts according to their length of followup: 2-4 years, 4-7 years, 7-10 years, and >10 years. Using previously described criteria for destructive arthritis in children with systemic-onset JRA, the patients were classified as either high risk or low risk for poor functional outcome based on the data from their 6-month visit. High-risk patients had active systemic disease (persistent fever or corticosteroid requirement for control of systemic disease) and a platelet count > or =600 x 10(9)/liter. Poor outcome was defined as moderate or severe disability (defined as a score of > or =0.75 on the Childhood Health Assessment Questionnaire) or disease-associated death. RESULTS: Among 122 eligible patients with systemic-onset JRA, we were able to contact 111 (91%) for outcome data. The mean followup period was 7.7 years (SD 3.7). The mean age at outcome assessment was 13.5 years (SD 5.3). There were 51 boys and 60 girls. Twenty-four patients (22%) had moderate-to-severe disability and 2 patients died; these 26 patients were considered to have had a poor outcome. We could determine risk classification for 104 patients. Twenty-four patients (23%) met the criteria for high risk at the 6-month visit. Overall, the risk of a poor functional outcome was significantly higher in the high-risk group (relative risk 3.3, 95% confidence interval [95% CI] 1.73-6.43, P = 0.0004). This risk was most marked in the cohort with > 10 years of followup (relative risk 4.3, 95% CI 1.82-10.29, P = 0.006). CONCLUSION: The presence of active systemic disease at 6 months, as characterized by fever or the need for corticosteroids, and thrombocytosis strongly predicted the development of a poor functional outcome in these patients. This was especially apparent with longterm followup. Our study validates the previously developed prognostic criteria for systemic-onset JRA.
Assuntos
Artrite Juvenil/fisiopatologia , Atividades Cotidianas , Antirreumáticos/uso terapêutico , Artrite Juvenil/tratamento farmacológico , Criança , Pré-Escolar , Humanos , Inquéritos e Questionários , Fatores de Tempo , Resultado do TratamentoRESUMO
About 50% of 1,057 green ash (Fraxinus pennsylvanica) systematically sampled in the Great Plains and Rocky Mountain regions had substantial dieback (>10% of crown branches with dieback), and the average growth ring width during the last 20 years was 2.9 mm. The overall condition of the population was rated fair. Ash yellows phytoplasmas were identified at 102 of 106 sites throughout six U.S. states (North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas) and three Canadian provinces (Alberta, Saskatchewan, Manitoba). These phytoplasmas had not previously been known in Alberta, Saskatchewan, Manitoba, Wyoming, Colorado, or Kansas. Incidence of phytoplasmal detection ranged from 16% in Wyoming to 71% in South Dakota. Incidence varied in the range 41 to 67% across site types and crown dieback classes. Incidence was highest in rural plantings, in trees with the most crown dieback, and in larger diameter trees. No significant relationships were detected between presence of ash yellows phytoplasmas and radial growth rates of trees.
RESUMO
Cancer cells maintain a high glycolytic rate even in the presence of oxygen, a phenomenon first described over 70 years ago and known historically as the Warburg effect. Fructose 2,6-bisphosphate is a powerful allosteric regulator of glycolysis that acts to stimulate the activity of 6-phosphofructo-1-kinase (PFK-1), the most important control point in mammalian glycolysis. The steady state concentration of fructose 2,6-bisphosphate in turn depends on the activity of the enzyme 6-phosphofructo-2-kinase (PFK-2)/fructose-2, 6-bisphosphatase, which is expressed in several tissue-specific isoforms. We report herein the identification of a gene product for this enzyme that is induced by proinflammatory stimuli and which is distinguished by the presence of multiple copies of the AUUUA mRNA instability motif in its 3'-untranslated end. This inducible gene for PFK-2 is expressed constitutively in several human cancer cell lines and was found to be required for tumor cell growth in vitro and in vivo. Inhibition of inducible PFK-2 protein expression decreased the intracellular level of 5-phosphoribosyl-1-pyrophosphate, a product of the pentose phosphate pathway and an important precursor for nucleic acid biosynthesis. These studies identify a regulatory isoenzyme that may be essential for tumor growth and provide an explanation for long-standing observations concerning the apparent coupling of enhanced glycolysis and cell proliferation.
Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias/genética , Neoplasias/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Regiões 3' não Traduzidas/genética , Regulação Alostérica , Sequência de Aminoácidos , Sequência de Bases , Divisão Celular , Transformação Celular Neoplásica , Clonagem Molecular , Glicólise , Humanos , Dados de Sequência Molecular , Neoplasias/patologia , Fosfofrutoquinase-2 , RNA Mensageiro/análise , RNA Mensageiro/genética , Alinhamento de Sequência , Células Tumorais CultivadasRESUMO
Discovered in the early 1960s as a T cell cytokine, the protein mediator known as macrophage migration inhibitory factor (MIF) has been found recently to be a pituitary peptide released during the physiological stress response, a proinflammatory macrophage cytokine secreted after LPS stimulation, and a T cell product expressed as part of the antigen-dependent activation response. We report herein that MIF also plays a critical role in the innate host response to staphylococcal and streptococcal exotoxins. In RAW 264.7 or elicited mouse peritoneal macrophages, peak MIF secretion was induced by concentrations of the staphylococcal toxic shock syndrome (TSS) toxin 1 (TSST-1) and the streptococcal pyrogenic exotoxin A as low as 10 pg/ml. Moreover, dose-response studies of splenocyte cytokine production showed that lower concentrations of TSST-1 (10 pg/ml) were needed to release MIF than to induce interleukin 2 or interferon-gamma secretion (1 ng/ml). We also studied the effect of neutralizing anti-MIF antibodies on TSST-1-induced lymphocyte proliferation and lethal toxic shock. Pretreatment of C57BL/6 mice with anti-MIF antibody 2 hr before TSST-1 injection prevented spleen enlargement and reduced by 50% the proliferation of splenocytes measured ex vivo. In a lethal mouse model of TSST-1-induced shock, anti-MIF antibody increased survival from 8% to 54% (P < 0.0001). These studies indicate that Gram-positive exotoxins are extremely potent inducers of MIF secretion and establish a critical role for MIF and the macrophage in the pathogenesis of the TSSs and in the innate immune response.
Assuntos
Toxinas Bacterianas , Exotoxinas/farmacologia , Bactérias Gram-Positivas/imunologia , Ativação Linfocitária/efeitos dos fármacos , Fatores Inibidores da Migração de Macrófagos/fisiologia , Macrófagos Peritoneais/metabolismo , Superantígenos , Animais , Anticorpos/farmacologia , Divisão Celular/imunologia , Células Cultivadas , Modelos Animais de Doenças , Enterotoxinas/farmacologia , Inflamação/imunologia , Interferon gama/metabolismo , Interleucina-2/metabolismo , Fatores Inibidores da Migração de Macrófagos/imunologia , Camundongos , Hipófise/metabolismo , Choque Séptico/imunologia , Baço/metabolismo , Staphylococcus/imunologia , Streptococcus/imunologiaRESUMO
BACKGROUND: DNA modified by advanced glycation endproducts (AGEs) undergoes a high frequency of insertional mutagenesis. In mouse lymphoid cells, these mutations are due in part to the transposition of host genomic elements that contain a DNA region homologous to the Alu family of repetitive elements. One particular 853 bp insertion, designated INS-1, was identified previously as a DNA element common to plasmids recovered from multiple, independent lymphoid cell transfections. MATERIALS AND METHODS: To characterize the genomic origin of this element, we used a 281-bp region of non-Alu-containing INS-1 sequence, designated. CORE, as a probe in Southern hybridization and for screening a bacteriophage mouse genomic DNA library. The resultant clones were sequenced and localized within the mouse genome. RESULTS: Two distinct genomic clones of 15 kB and 17 kB in size were isolated. A 522-bp unique region common to INS-1 and corresponding to the CORE sequence was identified in each clone. In both cases, CORE was found to be surrounded by repetitive DNA sequences: a 339-bp MT repeat at the 5' end, and a 150-bp B1 repeat at the 3' end. The CORE sequence was localized to mouse chromosome 1. CONCLUSIONS: These studies revealed that the CORE region of INS is present in low copy number but is associated with known repetitive DNA elements. The presence of these repetitive elements may facilitate the transposition of CORE by recombination or other, more complex rearrangement events, and explain in part the origin of AGE-induced insertional mutations.
Assuntos
Elementos de DNA Transponíveis/genética , DNA/análise , Biblioteca Genômica , Produtos Finais de Glicação Avançada/metabolismo , Sequências Repetitivas de Ácido Nucleico/genética , Animais , Sequência de Bases , Southern Blotting , Linhagem Celular , Mapeamento Cromossômico , DNA/metabolismo , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Glucocorticoid hormones are important for vital functions and act to modulate inflammatory and immune responses. Yet, in contrast to other hormonal systems, no endogenous mediators have been identified that can directly counter-regulate their potent anti-inflammatory and immunosuppressive properties. Recent investigations of the protein macrophage migration inhibitory factor (MIF), which was discovered originally to be a T-lymphocyte-derived factor, have established it to be a pro-inflammatory pituitary and macrophage cytokine and a critical mediator of septic shock. Here we report the unexpected finding that low concentrations of glucocorticoids induce rather than inhibit MIF production from macrophages. MIF then acts to override glucocorticoid-mediated inhibition of cytokine secretion by lipopolysaccharide (LPS)-stimulated monocytes and to overcome glucocorticoid protection against lethal endotoxaemia. These observations identify a unique counter-regulatory system that functions to control inflammatory and immune responses.
Assuntos
Citocinas/biossíntese , Glucocorticoides/fisiologia , Fatores Inibidores da Migração de Macrófagos/fisiologia , Macrófagos/imunologia , Animais , Western Blotting , Linhagem Celular , Citocinas/antagonistas & inibidores , Dexametasona/farmacologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Hidrocortisona/fisiologia , Imunidade/fisiologia , Inflamação/imunologia , Lipopolissacarídeos/imunologia , Ativação de Macrófagos , Fatores Inibidores da Migração de Macrófagos/biossíntese , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Choque Séptico/imunologia , Linfócitos T/imunologiaRESUMO
BACKGROUND: The host response to tissue injury requires a complex interplay of diverse cellular, humoral, and connective tissue elements. Fibroblasts participate in this process by proliferating within injured sites and contributing to scar formation and the longterm remodeling of damaged tissue. Fibroblasts present in areas of tissue injury generally have been regarded to arise by recruitment from surrounding connective tissue; however this may not be the only source of these cells. MATERIALS AND METHODS: Long-term culture of adherent, human, and murine leukocyte subpopulations was combined with a variety of immunofluorescence and functional analyses to identify a blood-borne cell type with fibroblast-like properties. RESULTS: We describe for the first time a population of circulating cells with fibroblast properties that specifically enter sites of tissue injury. This novel cell type, termed a "fibrocyte," was characterized by its distinctive phenotype (collagen+/vimentin+/CD34+), by its rapid entry from blood into subcutaneously implanted wound chambers, and by its presence in connective tissue scars. CONCLUSIONS: Blood-borne fibrocytes contribute to scar formation and may play an important role both in normal wound repair and in pathological fibrotic responses.
Assuntos
Fibroblastos/fisiologia , Leucócitos/citologia , Proteínas Nucleares , Fatores de Transcrição , Cicatrização/fisiologia , Animais , Sequência de Bases , Medula Óssea/efeitos da radiação , Células da Medula Óssea , Antígenos CD4/metabolismo , Adesão Celular , Células Cultivadas , Centrifugação , Quimera , Colágeno/química , Colágeno/metabolismo , Tecido Conjuntivo/irrigação sanguínea , Tecido Conjuntivo/fisiologia , Citoesqueleto , Proteínas de Ligação a DNA/genética , Relação Dose-Resposta à Radiação , Feminino , Fibroblastos/química , Fibroblastos/citologia , Citometria de Fluxo/métodos , Imunofluorescência , Humanos , Imuno-Histoquímica , Leucócitos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , Dados de Sequência Molecular , Fenótipo , Proteína da Região Y Determinante do Sexo , Fatores de Tempo , Transplante Heterólogo , Vimentina/químicaRESUMO
This article describes a support group for parents and caretakers of children being treated for human immunodeficiency virus (HIV) infection in a hospital outpatient clinic. Issues involved in the establishment of the group are discussed, including the population, the setting, the choice of group modality, planning of the group, and recruitment and composition of the group. Predominant group themes included guilt, fear, anger, and loss of control. Specific issues raised included deterioration in the child's condition, myths about HIV transmission, and coping with death. Therapeutic interventions by leaders and group members are described. The need to use alternate models of support groups and to allow departures from standard group techniques in this context is emphasized.
Assuntos
Cuidadores/psicologia , Infecções por HIV , Pais/psicologia , Desenvolvimento de Programas , Grupos de Autoajuda , Adaptação Psicológica , Emoções , Humanos , Lactente , Autoimagem , Isolamento Social/psicologiaRESUMO
Sialyltransferases (CMP-N-acetylneuraminic acid:glycoprotein sialyltransferases, EC 2.4.99.1) are involved in the transfer of a sialic acid moiety from CMP-N-acetylneuraminic acid (CMP-NeuAc) to an oligosaccharide side-chain of an acceptor, asialoglycoprotein (AGP), according to the following reaction: CMP-NeuAc + AGP----NeuAc-O-AGP + CMP. This enzyme occurs in elevated levels in the sera of patients with a wide variety of neoplastic diseases and its assay might be useful in monitoring treatment. Radioactive CMP-NeuAc has been used in assays and the radioactive sialylated product separated and counted by liquid scintillation spectrometry. This study shows that a simple, rapid, non-radiochemically based high-performance liquid chromatographic method developed for the analysis of CMP-sialic acid synthetase can be used for the quantitation of sialyltransferase activity by monitoring simultaneously the utilization of CMP-NeuAc and the release of CMP. We describe the application of this method to assay of commercially available sialyltransferase activity and to activities from synovial, ascites and gastric fluids.
Assuntos
Sialiltransferases/análise , Animais , Ascite/enzimologia , Cromatografia Líquida de Alta Pressão , Ácido N-Acetilneuramínico do Monofosfato de Citidina/análise , Suco Gástrico/enzimologia , Humanos , Camundongos , Orosomucoide/análise , Ratos , Líquido Sinovial/enzimologia , beta-D-Galactosídeo alfa 2-6-SialiltransferaseRESUMO
The first part of this article addresses the neuropsychiatric aspects of human immunodeficiency virus (HIV) infection in children and adolescents, including developmental delay, depression, and dementia. The specific clinical issues of disclosure of diagnosis and discussion of death with a child are examined. The second part presents aspects of the impact of AIDS on families, approaches to HIV antibody testing, and therapeutic interventions for the family.