RESUMO
Background: Adjuvant chemoradiation (CRT) is standard for head and neck squamous cell carcinoma (HNSCC) patients with positive margins or extranodal extension (ENE) following surgery. However, emerging evidence suggests the number of positive lymph nodes (LNs) is the dominant determinant of survival in non-oropharyngeal HNSCC and thus may better identify those benefiting from treatment intensification. Patients and methods: Patients from the National Cancer Database diagnosed with non-oropharyngeal HNSCC (oral cavity, larynx, hypopharynx) between 2004 and 2014 and undergoing surgical resection, neck dissection, and postoperative radiotherapy (RT) were included. Multivariable regression with first-order interaction terms was used to model the interaction between postoperative CRT and continuous number of positive LNs with respect to overall survival. Results: In total, 7144 patients met inclusion criteria. In multivariable analysis, increasing number of positive LNs was associated with both increasing mortality (P < 0.001) and increasing benefit from postoperative CRT versus RT alone (interaction P < 0.001). While there was no benefit from postoperative CRT in patients with 0-2 LN+ [hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.86-1.07, P = 0.47], increased benefit was seen in those with 3-5 LN+ (HR 0.84, 95% CI 0.70-1.00, P = 0.05) and those with ≥6 LN+ (HR 0.65, 95% CI 0.51-0.82, P < 0.001) in multivariable models. By contrast, margin status and ENE did not reliably identify patients benefitting from postoperative CRT based on statistical tests of interaction. Even in patients with ENE, positive margins, or both, only those with ≥6 LN+ had improved survival with postoperative CRT. Conclusion: Increasing metastatic nodal burden was associated with increased benefit from CRT compared with RT alone, surpassing conventional high-risk factors in identifying patients benefiting from CRT. Stratification by metastatic LN number may characterize a very-high-risk patient cohort best suited for treatment intensification.
Assuntos
Quimiorradioterapia Adjuvante/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Linfonodos/patologia , Margens de Excisão , Carcinoma de Células Escamosas de Cabeça e Pescoço/secundário , Idoso , Terapia Combinada , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Prognóstico , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidade , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapia , Taxa de SobrevidaRESUMO
A remarkable, evidence-based trend toward de-escalation has reformed the practice of radioactive iodine (RAI) administration for thyroid cancer patients. Updated guidelines have supported both decreased RAI doses for select populations, as well as expanded definitions of low-risk and intermediate-risk patients that may not require RAI. Correspondingly, there is now increased flexibility for hemithyroidectomy without need for RAI, and relaxed TSH suppression targets for low-risk thyroidectomy patients. Clinical judgment remains indispensable where multiple risk factors co-exist that individually are not indications for RAI. This is especially salient in intermediate-risk patients with a less than excellent response to therapy, determined through thyroglobulin and ultrasound surveillance. Such judgment, however, may lead to patterns of inappropriate RAI practices or overuse with little benefit to the patient and unnecessary harm. A multidisciplinary, risk-adapted approach is ever more important and obliges the surgeon to understand the likelihood that their patients will receive RAI. The risks and benefits of RAI, its evolved role in contemporary guidelines, and current patterns of use among endocrinologists are reviewed, as well as the practical implications for thyroid surgeons.
Assuntos
Radioisótopos do Iodo/uso terapêutico , Neoplasias da Glândula Tireoide/radioterapia , Biomarcadores Tumorais/análise , Terapia Combinada , Tomada de Decisões , Humanos , Seleção de Pacientes , Guias de Prática Clínica como Assunto , Dosagem Radioterapêutica , Medição de Risco , Fatores de Risco , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/métodosRESUMO
The purpose of this investigation was to characterise the interactions of Cryptococcus neoformans with mammalian host alveolar epithelial cells and alveolar macrophages, with emphasis on the roles of the cryptococcal capsule and the host cell cytoskeletons. The adherence and internalisation of C. neoformans into mammalian lung cells and the roles of host cell cytoskeletons in host-pathogen interactions were studied using in vitro models coupled with a differential fluorescence assay, fluorescence staining, immunofluorescence and drug inhibition of actin and microtubule polymerisation. Under conditions devoid of opsonin and macrophage activation, C. neoformans has a high affinity towards MH-S alveolar macrophages, yet associated poorly to A549 alveolar epithelial cells. Acapsular C. neoformans adhered to and internalised into the mammalian cells more effectively compared to encapsulated cryptococci. Acapsular C. neoformans induced prominent actin reorganisation at the host-pathogen interface in MH-S alveolar macrophages, but minimally affected actin reorganisation in A549 alveolar epithelial cells. Acapsular C. neoformans also induced localisation of microtubules to internalised cryptococci in MH-S cells. Drug inhibition of actin and microtubule polymerisation both reduced the association of acapsular C. neoformans to alveolar macrophages. The current study visualises and confirms the interactions of C. neoformans with mammalian alveolar cells during the establishment of infection in the lungs. The acapsular form of C. neoformans effectively adhered to and internalised into alveolar macrophages by inducing localised actin reorganisation, relying on the host's actin and microtubule activities.
Assuntos
Citoesqueleto de Actina/metabolismo , Cryptococcus neoformans/fisiologia , Células Epiteliais/fisiologia , Interações Hospedeiro-Patógeno , Macrófagos/fisiologia , Microtúbulos/metabolismo , Animais , Adesão Celular , Linhagem Celular , Endocitose , Células Epiteliais/microbiologia , Cápsulas Fúngicas/genética , Cápsulas Fúngicas/metabolismo , Humanos , Macrófagos/microbiologia , CamundongosRESUMO
It stems from the magnetism: The extraction of stem/progenitor cells from the brain of live animals is possible using antibodies conjugated to magnetic nanoparticles (Ab-MNPs). The Ab-MNPs are introduced to a rat's brain with a superfine micro-syringe. The stem cells attach to the Ab-MNPs and are magnetically isolated and removed. They can develop into neurospheres and differentiate into different types of cells outside the subject body. The rat remains alive and healthy.
Assuntos
Anticorpos/química , Encéfalo/citologia , Separação Celular/métodos , Nanopartículas de Magnetita/química , Células-Tronco Neurais/citologia , Antígeno AC133 , Animais , Anticorpos/imunologia , Antígenos CD/imunologia , Antígenos CD/metabolismo , Separação Celular/instrumentação , Glicoproteínas/imunologia , Glicoproteínas/metabolismo , Células-Tronco Neurais/metabolismo , Tamanho da Partícula , Peptídeos/imunologia , Peptídeos/metabolismo , Ratos , Medicina RegenerativaRESUMO
SETTING: Few studies have evaluated the sclerosing efficacy of minocycline, and none have specifically compared its sclerosing efficacy and safety profiles with talc slurry in secondary spontaneous pneumothorax (SSP). DESIGN: A retrospective analysis was conducted in patients with SSP who underwent chemical pleurodesis from January to December 2004 with minocycline or talc slurry in 12 public hospitals of Hong Kong. RESULT: There were 121 episodes of minocycline pleurodesis and 64 episodes of talc slurry pleurodesis. Immediate procedural failure were similar in the minocycline and talc slurry groups (21.5% vs. 28.1%, P = 0.31). Presence of interstitial lung disease, ≥ 2 previous episodes of pneumothorax, requiring mechanical ventilation during pleurodesis and persistent air leak before pleurodesis were independently associated with procedural failure. Pain was experienced in respectively 44.6% and 37.5% of the minocycline and the talc slurry groups. Pain was more common in patients receiving high doses of talc (≥ 5 g; P = 0.03). Respiratory distress was found in respectively 1.7% and 1.6% of the minocycline and talc slurry groups. CONCLUSION: Minocycline and talc slurry had comparable sclerosing efficacy in SSP, with immediate success rates of >70%. Pain was the most common adverse effect and respiratory distress was uncommon. Both appeared to be effective and safe for chemical pleurodesis in SSP.
Assuntos
Minociclina/administração & dosagem , Pleurodese/métodos , Pneumotórax/terapia , Soluções Esclerosantes/administração & dosagem , Talco/administração & dosagem , Idoso , Distribuição de Qui-Quadrado , China , Feminino , Hospitais Públicos , Hospitais Universitários , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Dor/etiologia , Pleurodese/efeitos adversos , Pneumotórax/etiologia , Transtornos Respiratórios/etiologia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Prevenção Secundária , Resultado do TratamentoRESUMO
BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) is rising in many parts of the world. This is a study of risk factors for COPD in Chinese patients in Hong Kong. DESIGN: Case-control study matched by sex and age (+/-5 years). METHODS: A total of 289 consecutive patients with COPD were recruited from out-patient clinics while healthy controls were recruited from two sources: random population and community centres for senior citizens. All patients and controls underwent a questionnaire-based interview and spirometry. RESULTS: The mean ages of COPD patients and controls were 71.1 +/- 9.4 and 67.5 +/- 9.3 years, respectively. The male to female ratio of COPD patients was 5 to 1. Smoking was found to be the most important determinant for COPD, followed by poor education and low body mass index adjusted for confounders. A dose-dependent relationship was found between the risk of COPD and pack-years smoked. Place of birth, exposure to environmental tobacco smoke and a history of asthma and tuberculosis were not associated with increased risk of COPD. CONCLUSION: Despite a progressive reduction in prevalence, smoking remains the most important predictor of COPD in Hong Kong. Greater anti-smoking efforts are warranted.
Assuntos
Povo Asiático , Doença Pulmonar Obstrutiva Crônica/etnologia , Doença Pulmonar Obstrutiva Crônica/etiologia , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Hong Kong , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fumar/efeitos adversos , Fatores SocioeconômicosRESUMO
PURPOSE: Given that p53 is a tumor suppressor that plays a central role in the cellular response to DNA damage and that more than 50% of all cancers have mutated p53, the wider utility of photodynamic therapy (PDT) in the treatment of cancer will depend on an understanding of whether p53 status modulates response to PDT. In this study, we investigated the photosensitivity of isogenic cell lines that differ only in their p53 status to PDT using hypericin as the photosensitizer. METHODS: Acute (MTT) and chronic (clonogenic) cytotoxic assays were performed on two osteosarcoma cell-lines (U2OS and U2OS+p53DD) that are isogenic except that the latter expresses dominant negative p53. The inducible expression of p53 was determined on western blots. Uptake of hypericin, cell cycle profile analysis, measurement of membrane phosphatidylserine externalization and changes in mitochondrial membrane potential were investigated using flow cytometry. RESULTS: Hypericin uptake was observed to be equivalent in U2OS and U2OS+p53DD cells. There were no significant differences in cell killing between these cell-lines in both the MTT and clonogenic assays (IC(50) of 0.4 microg/ml from MTT assay). p53 expression did not increase up to 24 h after PDT treatment in both cell lines. There were also no significant differences in the cell-cycle arrest profiles and timing of onset of apoptosis. CONCLUSIONS: Taken together, these results suggest that the status of p53 may not be important in PDT-mediated cell killing or induction of apoptosis. By extension, these results imply that PDT may be used with equal efficacy for the treatment of p53-positive and -negative tumors.
Assuntos
Perileno/análogos & derivados , Fotoquimioterapia , Radiossensibilizantes/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Antracenos , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Osteossarcoma/tratamento farmacológico , Osteossarcoma/metabolismo , Perileno/farmacocinética , Perileno/farmacologia , Radiossensibilizantes/farmacocinéticaRESUMO
Allergen-reactive T helper type-2 (Th2) cells and proinflammatory cytokines have been suggested to play an important role in the induction and maintenance of the inflammatory cascade in allergic asthma. We compared the plasma concentrations of novel proinflammatory cytokines IL-17 and IL-18, other proinflammatory cytokines IL-6 and IL-12, Th2 cytokines IL-10 and IL-13, and intracellular interferon-gamma (IFN-gamma) and IL-4 in Th cells of 41 allergic asthmatics and 30 sex- and age-matched health control subjects. Plasma cytokines were measured by enzyme-linked immunosorbent assay. Intracellular cytokines were quantified by flow cytometry. Plasma IL-18, IL-12, IL-10, IL-13 concentrations were significantly higher in allergic asthmatic patients than normal control subjects (IL-18: median 228.35 versus 138.72 pg/ml, P < 0.001; IL-12: 0.00 versus 0.00 pg/ml, P = 0.001; IL-10: 2.51 versus 0.05 pg/ml, P < 0.034; IL-13: 119.38 versus 17.89 pg/ml, P < 0.001). Allergic asthmatic patients showed higher plasma IL-17 and IL-6 concentrations than normal controls (22.40 versus 11.86 pg/ml and 3.42 versus 0.61 pg/ml, respectively), although the differences were not statistically significant (P = 0.077 and 0.053, respectively). The percentage of IFN-gamma-producing Th cells was significantly higher in normal control subjects than asthmatic patients (23.46 versus 5.72%, P < 0.001) but the percentage of IL-4 producing Th cells did not differ (0.72 versus 0.79%, P > 0.05). Consequently, the Th1/Th2 cell ratio was significantly higher in normal subjects than asthmatic patients (29.6 versus 8.38%, P < 0.001). We propose that allergic asthma is characterized by an elevation of both proinflammatory and Th2 cytokines. The significantly lower ratio of Th1/Th2 cells confirms a predominance of Th2 cells response in allergic asthma.
Assuntos
Asma/imunologia , Citocinas/sangue , Ribonucleases , Células Th1/imunologia , Células Th2/imunologia , Adulto , Idoso , Asma/diagnóstico , Proteínas Sanguíneas/análise , Proteínas Granulares de Eosinófilos , Feminino , Humanos , Hipersensibilidade Imediata/imunologia , Imunoglobulina E/sangue , Interferon gama/sangue , Interleucina-10/sangue , Interleucina-12/sangue , Interleucina-13/sangue , Interleucina-17/sangue , Interleucina-18/sangue , Interleucina-4/sangue , Interleucina-6/sangue , Masculino , Pessoa de Meia-IdadeRESUMO
2-Formyl-1-hydroxyanthraquinone, along with ten other known anthraquinones (1-hydroxy-2-methylanthraquinone, nordamnacanthal, damnacanthal, lucidin-?-methyl ether, rubiadin, rubiadin-1-methyl ether, soranjidiol, morindone, morindone-5-methyl ether and alizarin-1-methyl ether), isolated from the roots of Morinda elliptica , were assayed for anti-HIV, cytotoxic and antimicrobial activites. Only damnacanthal showed moderate activity against HIV. It was cytotoxic towards the MCF-7 (breast carcinoma) and CEM-SS (T-lymphoblastic leukaemia) cell line. Nordamnacanthal was very cytotoxic against the CEM-SS cell lines. Other anthraquinones that showed strong cytotoxicity towards the cell lines tested were lucidin-?-methyl ether (CEM-SS and MCF-7) and rubiadin (CEM-SS). Three anthraquinones viz., nordamnacanthal, damnacanthal and morindone, were found to have strong antimicrobial activity.
RESUMO
Interleukin-5 has a specific role in various eosinophilic activities. It is the predominant cytokine produces by activated T-lymphocytes isolated from patients with idiopathic hypereosinophilic syndrome. We studied a young patient suffering from idiopathic hypereosinophilic syndrome who presented with Horner's syndrome, peripheral neuropathy and skin ulcers. The IL-5 gene expression by CD4+ T-lymphocytes and the peripheral eosinophil count were raised. The skin ulcers continued to deteriorate despite a swift reduction of the IL-5 gene expression and peripheral eosinophil count following systemic corticosteroid treatment. We suggest that peripheral eosinophilia may not be responsible for the damage in skin lesions and more aggressive treatment may be required.
Assuntos
Síndrome Hipereosinofílica/metabolismo , Interleucina-5/metabolismo , RNA Mensageiro/metabolismo , Corticosteroides/uso terapêutico , Adulto , Linfócitos T CD4-Positivos , Eosinófilos , Expressão Gênica , Humanos , Síndrome Hipereosinofílica/tratamento farmacológico , Masculino , Fatores de TempoRESUMO
In contrast to Western countries, erosive esophagitis has been considered less common, Barrett's esophagus presumed less frequent, and hiatal hernia extremely uncommon in the Orient. However, accelerated modernization and adoption of Western customs have resulted in marked life-style changes in many Asians in the Orient that may potentially affect the frequency of erosive esophagitis and Barrett's esophagus in this population. Our aim was to determine the current frequency of erosive esophagitis, Barrett's esophagus, and other gastroesophageal reflux disease complications in self-referred Chinese patients undergoing upper gastrointestinal endoscopy in Taipei, Taiwan. Between July 1991 and June 1992, 464 consecutive patients underwent endoscopy for a variety of upper gastrointestinal symptoms at a major medical center. The presence of erosive esophagitis, strictures, Barrett's esophagus, and hiatal hernia was recorded. The extent of mucosal injury was determined by using the Savary-Miller grading system. Sixty-six (14.5%) patients were found to have erosive esophagitis, 9 (2%), Barrett's esophagus, and 32 (7%) hiatal hernias. Erosive esophagitis showed a male-to-female preponderance of 3.1:1. Disease severity increased with age and peaked during the sixth and seventh decades. We concluded that in contrast to previous experience, the Chinese population in Taiwan appears to have a higher frequency of erosive esophagitis, Barrett's esophagus, and hiatal hernia. Increased fat consumption, aging, and other possible factors are suggested as possible mechanisms.
Assuntos
Esôfago de Barrett/epidemiologia , Esofagite/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Esofagite/complicações , Feminino , Refluxo Gastroesofágico/epidemiologia , Hérnia Hiatal/complicações , Hérnia Hiatal/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Taiwan/epidemiologiaRESUMO
BACKGROUND: Helicobacter pylori (H. pylori) is an important predisposing factor in peptic ulcer disease. Many tests have been proposed, but there is no generally accepted single method for the detection of H. pylori. This study compared the four available methods in the detection of H. pylori. METHODS: One hundred and thirteen patients were studied with endoscopic biopsy. Biopsy specimens were examined with modified Giemsa stain and rapid urease (CLO) test. Serology (ELISA) and 13C-urea breath test (13C-UBT) were also performed. The 13C-UBT results were expressed at an excess delta 13CO2 excretion of 5 per mil as the upper limit. Multiple breath samples were collected 15, 30 and 60 minutes following 13C-urea ingestion (t = 15, 30, 60) in the first 60 patients. Gastric inflammatory changes were graded according to the Whitehead classification. The diagnostic gold standard was defined when three or more of the four test parameters showed positive. RESULTS: According to this diagnostic gold standard, the positive rates of H. pylori were 97.9% for duodenal ulcer, 81.8% for gastric ulcer, 47.6% for symptomatic gastritis and 13.6% for asymptomatics. Rapid urease test and the 13C-UBT had better sensitivity (93.6% and 96.2%) and accuracy (93.8% and 93.8%). The specificity and positive predictive value for rapid urease test was better than 13C-UBT (94.3% v.s. 88.6%, 97.3% v.s. 94.9% respectively). Modified Giemsa stain had the lowest sensitivity (87.2%), and the ELISA test had the lowest specificity (71.4%). Severity of the gastric inflammatory processes was directly correlated with the excess delta 13CO2 (r = 0.576). CONCLUSIONS: Both the CLO and 13C-UBT had higher accuracy in the detection of H. pylori. When the CLO test result is positive, there is little additional diagnostic benefit from performing other tests. If patients refuse endoscopic examination, 13C-UBT is a good alternative for the detection of H. pylori, either during diagnosis or follow-up after therapy.
Assuntos
Ensaios Enzimáticos Clínicos , Infecções por Helicobacter/diagnóstico , Helicobacter pylori , Ureia/metabolismo , Urease/metabolismo , Adulto , Idoso , Testes Respiratórios , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A 32-year-old Chinese man with cystic lymphangioma of the transverse colon is described. He presented with a 1-year history of altered bowel habits. Double-contrast barium enema study demonstrated a submucosal lesion in the midportion of the transverse colon with intact mucosa. Computed tomography (CT) showed a round 3.0-cm submucosal cystic mass lesion. Colonoscopy revealed a smooth, soft polypoid mass on a broad base. He underwent segmental resection of the colon. Histologically, the lesion was characterized by cystic lymphangioma originating from the submucosa. The clinical features, radiology, appropriate treatment, and possible pathogenesis of colonic lymphangioma are discussed.
Assuntos
Neoplasias do Colo/diagnóstico , Linfangioma Cístico/diagnóstico , Adulto , Sulfato de Bário , Neoplasias do Colo/diagnóstico por imagem , Pólipos do Colo/diagnóstico , Pólipos do Colo/diagnóstico por imagem , Colonoscopia , Meios de Contraste , Enema , Humanos , Linfangioma Cístico/diagnóstico por imagem , Masculino , Tomografia Computadorizada por Raios XRESUMO
Attempts to maintain or expand primitive hematopoietic stem cells in vitro without the concomitant loss of their differentiative and proliferative potential in vivo have largely been unsuccessful. To investigate this problem, we compared the ability of three cloned bone marrow (BM) stromal cell lines to support the growth of primitive Thy-1lo Sca-1+H-2Khi cells isolated by fluorescence-activated cell sorting from the BM of Ly-5.2 mice treated 1 day previously with 5-fluo- rouracil. Sorted cells were highly enriched in cobblestone area-forming cells (CAFC), but their frequency was dependent on the stromal cell lines used in this assay (1 per 45 cells on SyS-1; 1 per 97 cells on PA6). In the presence of recombinant leukemia inhibitory factor (LIF), CAFC cloning efficiency was increased to 1 per 8 cells on SyS-1 and 1 per 11 cells on PA6, thus showing the high clonogenicity of this primitive stem cell population. More primitive stem cells with competitive repopulating potential were measured by injecting the sorted cells into lethally irradiated Ly-5.1 mice together with 10(5) radioprotective Ly-5.1 BM cells whose long-term repopulating ability has been "compromised" by two previous cycles of marrow transplantation and regeneration. Donor-derived lymphocytes and granulocytes were detected in 66% of animals injected with 50 sorted cells. To quantitate the maintenance of competitive repopulating units (CRU) by stromal cells, sorted cells were transplanted at limiting dilution before and after being cultured for 2 weeks on adherent layers of SyS-1, PA6, or S17 cells. CRU represented 1 per 55 freshly sorted cells. CRU could be recovered from cocultures supported by all three stromal cell lines, but their numbers were approximately-sevenfold less than on day 0. In contrast, the addition of LIF to stromal cultures improved CRU survival by 2.5-fold on S17 and PA6 cells (approximately two-fold to threefold decline), and enabled their maintenance on SyS-1. LIF appeared to act indirectly, because alone it did not support the proliferation of Thy-1lo Sca-1+H-2Khi cells in stroma-free cultures. Polymerase chain reaction (RT-PCR) analysis revealed that Interleukin-1beta (IL-1 beta) IL-2, IL-6, granulocyte-colony stimulating factor, granulocyte macrophage-colony stimulating factor, transforming growth factors, LIF, and Steel Factor (SLF) mRNAs were upregulated in SyS-1 within 1 to 6 hours of LIF-stimulation. To determine if increased expression of SLF by LIF-stimulated SyS-1 cells could account for their capacity to support stem cells, sorted calls were cocultured on simian CV-E cells that were transfected with an expression vector encoding membrane-bound SLF, or supplemented with soluble SLF. In both cases, SLF synergized with IL-6 produced endogenously by CV-E cells enabling CAFC growth equivalent to that on LIF-stimulated SyS-1. CAFC development on LIF-stimulated SyS-1 could also be completely abrogated by an anti-SLF antibody. These data provide evidence for a role of LIF in the support of long-term repopulating stem cells by indirectly promoting cytokine expression by BM stroma. Furthermore, we have used quantitative assays to show a maintenance of CRU numbers, with retention of in vivo function following ex vivo culture.
Assuntos
Tecido Conjuntivo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Inibidores do Crescimento/farmacologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Interleucina-6 , Linfocinas/farmacologia , Animais , Antígenos de Diferenciação/análise , Sequência de Bases , Células da Medula Óssea , Transplante de Medula Óssea , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Técnicas de Cocultura , Ensaio de Unidades Formadoras de Colônias , Células do Tecido Conjuntivo , Fluoruracila/toxicidade , Sobrevivência de Enxerto , Antígenos H-2/genética , Hematopoese , Células-Tronco Hematopoéticas/citologia , Fator Inibidor de Leucemia , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Antígenos Thy-1/genéticaRESUMO
Files from a transgenic line of Drosophila melanogaster with two copies of the metallothionein allele Mtn3 were more tolerant to cadmium than strains with only one copy of the gene. However, flies with the Mtn3 allele were as tolerant as flies with the Mtn3 allele, despite the level of expression of Mtn3 being three times higher than of Mtn3. We propose that the substitution of Lys-40 (in Mtn3) for Glu-40 (in Mtn1) accounts for a reduction in binding affinity of Mtn1, which offsets the increased expression levels.
Assuntos
Cádmio/metabolismo , Drosophila melanogaster/genética , Metalotioneína/genética , Alelos , Animais , Sequência de Bases , Northern Blotting , Tolerância a Medicamentos/genética , Expressão Gênica , Masculino , Dados de Sequência Molecular , TransfecçãoRESUMO
The cytokine interleukin-10 (IL-10) has several important activities on cells of the immune system. IL-10 profoundly suppresses activation of macrophages, inhibiting their ability to secrete cytokines and serve as accessory cells for stimulation of T cell and natural killer (NK) cell function. IL-10 also plays a role in stimulating proliferation and differentiation of B cells, mast cells, and both mature and immature T cells. At least two herpesviruses harbor analogs of the IL-10 gene; the Epstein-Barr virus (EBV) homolog (BCRF1, viral IL-10, vIL-10) shares several of the cellular cytokine's activities, one or all of which may be important in the host-virus relationship. This article reviews recent studies on the function of IL-10 and discusses the initial characterization of its receptor.
Assuntos
Interleucina-10/fisiologia , Receptores de Interleucina/fisiologia , Animais , Células Apresentadoras de Antígenos/imunologia , Autoimunidade/imunologia , Linfócitos B/citologia , Diferenciação Celular , Genes , Genes Virais , Hematopoese , Herpesvirus Humano 4/crescimento & desenvolvimento , Humanos , Tolerância Imunológica , Inflamação/imunologia , Ativação Linfocitária , Ativação de Macrófagos , Macrófagos/imunologia , Receptores de Interleucina-10 , Linfócitos T/imunologia , Células Th1/imunologia , Células Th2/imunologia , Proteínas Estruturais Virais/genéticaRESUMO
cDNA clones encoding a human IL-10R (hIL-10R) from a Burkitt lymphoma cell line, BJAB, express a 90 to 110 kDa polypeptide in COS7 cells that binds hIL-10 specifically. The predicted amino acid sequence of hIL-10R is 60% identical and 73% similar to mouse IL-10R (mIL-10R). rIL-10R expressed in an IL-3-dependent mouse pro-B cell line (Ba/F3) binds hIL-10 with high affinity (200 to 250 pM), and the transfected cells exhibit a proliferative response to hIL-10. Mouse IL-10 does not bind to hIL-10R, and hIL-10R-expressing Ba/F3 cells do not respond to the mouse cytokine, observations consistent with the known species specificity of IL-10. Expression of hIL-10R mRNA seems to be restricted mainly to human hemopoietic cells and cell lines. In a number of human T cell clones, expression of hIL-10R mRNA is down-regulated after activation of the cells with anti-CD3 Ab and phorbol ester. The hIL-10R gene is on human chromosome 11. Like mIL-10R, hIL-10R is structurally related to IFNR. Because IL-10 inhibits macrophage activation by IFN-gamma, this relationship suggests possible shared receptor or signal transduction pathway components.
Assuntos
Receptores de Interleucina/genética , Sequência de Aminoácidos , Sequência de Bases , Linhagem Celular , Mapeamento Cromossômico , Clonagem Molecular , DNA Complementar/química , Humanos , Interferon gama/farmacologia , Dados de Sequência Molecular , RNA Mensageiro/análise , Receptores de Interferon/análise , Receptores de Interleucina/análise , Receptores de Interleucina-10RESUMO
We isolated cDNAs encoding a mouse interleukin 10 receptor (mIL-10R) from mouse mast cell and macrophage cell lines. The two cDNAs are substantially identical and express an approximately 110-kDa polypeptide in COS7 cells, which binds mIL-10 specifically. A mouse pro-B-cell line (Ba/F3) expressing transfected recombinant mIL-10R binds IL-10 with high affinity (approximately 70 pM) and proliferates in response to mIL-10. mIL-10R is structurally related to interferon receptors (IFNRs). Since IL-10 inhibits macrophage activation by IFN-gamma, a possible implication of this relationship interaction of IL-10R and IFN-gamma R or their signaling pathways.