RESUMO
BACKGROUND: Incidence of ductal carcinoma in situ (DCIS) has increased in recent decades because of breast cancer screening. This study comprised a long-term survival analysis of DCIS using 10-year territory-wide data from the Hong Kong Cancer Registry. METHODS: This study included all patients diagnosed with DCIS in Hong Kong from 1997 to 2006. Exclusion criteria were age <30 years or ≥70 years, lobular carcinoma in situ, Paget's disease, and co-existing invasive carcinoma. Patients were stratified into those diagnosed from 1997 to 2001 and those diagnosed from 2002 to 2006. The 5- and 10-year breast cancer-specific survival rates were evaluated; standardised mortality ratios were calculated. RESULTS: Among the 1391 patients in this study, 449 were diagnosed from 1997 to 2001, and 942 were diagnosed from 2002 to 2006. The mean age at diagnosis was 49.2±9.2 years. Overall, 51.2% of patients underwent mastectomy and 29.5% received adjuvant radiotherapy. The median follow-up interval was 11.6 years; overall breast cancer-specific mortality rates were 0.3% and 0.9% after 5 and 10 years of follow-up, respectively. In total, 109 patients (7.8%) developed invasive breast cancer after a considerable delay. Invasive breast cancer rates were comparable between patients diagnosed from 1997 to 2001 (n=37, 8.2%) and those diagnosed from 2002 to 2006 (n=72, 7.6%). CONCLUSION: Despite excellent long-term survival among patients with DCIS, these patients were more likely to die of breast cancer, compared with the general population of women in Hong Kong.
Assuntos
Neoplasias da Mama/mortalidade , Carcinoma Intraductal não Infiltrante/mortalidade , Detecção Precoce de Câncer/mortalidade , Adulto , Idoso , Neoplasias da Mama/terapia , Carcinoma Intraductal não Infiltrante/terapia , Feminino , Hong Kong/epidemiologia , Humanos , Incidência , Análise de Séries Temporais Interrompida , Programas de Rastreamento/mortalidade , Mastectomia/mortalidade , Pessoa de Meia-Idade , Radioterapia Adjuvante/mortalidade , Sistema de Registros , Análise de Sobrevida , Taxa de Sobrevida , Fatores de TempoRESUMO
Killer immunoglobulin-like receptors (KIRs) interact with human leucocyte antigen (HLA) class I ligands and play a key role in the regulation and activation of NK cells. The functional importance of KIR-HLA interactions has been demonstrated for a number of chronic viral infections, but to date only a few studies have been performed in the context of acute self-limited viral infections. During our investigation of CD8(+) T cell responses to a conserved HLA-B57-restricted epitope derived from dengue virus (DENV) non-structural protein-1 (NS1), we observed substantial binding of the tetrameric complex to non-T/non-B lymphocytes in peripheral blood mononuclear cells (PBMC) from a long-standing clinical cohort in Thailand. We confirmed binding of the NS1 tetramer to CD56(dim) NK cells, which are known to express KIRs. Using depletion studies and KIR-transfected cell lines, we demonstrated further that the NS1 tetramer bound the inhibitory receptor KIR3DL1. Phenotypical analysis of PBMC from HLA-B57(+) subjects with acute DENV infection revealed marked activation of NS1 tetramer-binding natural killer (NK) cells around the time of defervescence in subjects with severe dengue disease. Collectively, our findings indicate that subsets of NK cells are activated relatively late in the course of acute DENV illness and reveal a possible role for specific KIR-HLA interactions in the modulation of disease outcomes.
Assuntos
Vírus da Dengue/química , Dengue/imunologia , Células Matadoras Naturais/imunologia , Fragmentos de Peptídeos/imunologia , Receptores KIR3DL1/imunologia , Receptores KIR3DL1/metabolismo , Proteínas não Estruturais Virais/imunologia , Doença Aguda , Adolescente , Criança , Pré-Escolar , Dengue/fisiopatologia , Dengue/virologia , Vírus da Dengue/imunologia , Epitopos de Linfócito T/imunologia , Feminino , Antígenos HLA-B/imunologia , Humanos , Lactente , Células Matadoras Naturais/fisiologia , Leucócitos Mononucleares/imunologia , Masculino , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Proteínas não Estruturais Virais/metabolismoRESUMO
AIMS: The current gold standard of treatment for ductal carcinoma in situ (DCIS) is surgical resection with or without adjuvant radiotherapy. However, the increased detection and radical treatment of DCIS did not result in a declined incidence of invasive breast cancers, leading to the debate if DCIS has been overtreated. While ongoing randomised controlled trials on active surveillance of DCIS are still in progress, this systematic review aims to evaluate the best evidence on conservative treatment for DCIS from the literature. MATERIALS AND METHODS: This systematic review was conducted in line with the PRISMA statement. We included all relevant studies published up to June 2022 for analysis. The primary outcomes were overall survival and breast cancer-specific survival (BCSS) of conservative treatment for DCIS. RESULTS: Three studies, with a total of 34 007 women with low-risk DCIS, were included in the analysis. Active and conservative treatments both resulted in excellent 10-year BCSS, with no statistically insignificant difference (98.6% versus 96.0%, 31 478 women). One study comparing 5-year BCSS of active and conservative treatments only in subjects aged over 80 years also reported [AQ1]an insignificant difference (98.2% versus 96.0%, 2529 women). One study measuring 5- and 10-year overall survival between the treatment groups also reported [AQ1]an insignificant difference (5-year: 96.2% versus 92.4%; 10-year: 85.6% versus 86.7%, 31 106 women). CONCLUSION: BCSS between active and conservative treatment for women with low-risk DCIS is both excellent and comparable, suggesting that conservative treatment is a possible alternative without compromising survival.
Assuntos
Neoplasias da Mama , Carcinoma Ductal de Mama , Carcinoma Intraductal não Infiltrante , Feminino , Humanos , Idoso de 80 Anos ou mais , Carcinoma Intraductal não Infiltrante/terapia , Carcinoma Intraductal não Infiltrante/patologia , Tratamento Conservador , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Neoplasias da Mama/patologia , Mama/patologiaRESUMO
BACKGROUND: With the growing epidemic of obesity, few data are available regarding adipose distribution and the severity of sleep apnoea. Our aim was to measure precisely adipose distribution with dual-energy X-ray absorptiometry (DXA) in a morbidly obese population with and without obstructive sleep apnoea (OSA). METHODS: Morbidly obese female subjects without a history of OSA underwent overnight polysomnography and DXA analysis. Subject demographics, DXA variables, serum laboratory markers and physical exam characteristics were compared between individuals with and without OSA. RESULTS: For the study population (n= 26), mean body mass index (BMI) was 45.9 ± 7.8 kg/m(2); mean age was 47.5 ± 10.2 years and all were female. The central adiposity ratio (CAR) was higher in individuals with OSA (apnoea-hypopnoea index > 5) than those without OSA (1.1 ± 0.05 vs 1.0 ± 0.04; P = 0.004). No difference was observed in Epworth Sleepiness Scale scores, body mass index (BMI) or neck circumference between groups. CONCLUSIONS: OSA is associated with increased central adipose deposition in patients with a BMI of >40 kg/m(2). These data may be helpful in designing future studies regarding the pathophysiology of OSA, and potential treatment options.
Assuntos
Obesidade Abdominal/complicações , Obesidade Mórbida/complicações , Apneia Obstrutiva do Sono/complicações , Absorciometria de Fóton/métodos , Adulto , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade Abdominal/diagnóstico , Obesidade Abdominal/fisiopatologia , Obesidade Mórbida/diagnóstico , Obesidade Mórbida/fisiopatologia , Polissonografia/métodos , Índice de Gravidade de Doença , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/fisiopatologiaRESUMO
AIMS: The LORIS trial is an ongoing phase III clinical trial on low risk ductal carcinoma in situ (DCIS). DCIS patients aged ≥46 years with screen-detected low/intermediate nuclear grade were considered low risk and were randomised into surveillance or standard surgery. Here we review the 10-year territory-wide breast cancer registry database and evaluate the clinical outcomes of low versus high risk DCIS patients. MATERIALS AND METHODS: This was a retrospective study of a prospectively maintained territory-wide breast cancer registry in Hong Kong. RESULTS: Between 1997 and 2006, 1391 DCIS patients were identified from the Hong Kong cancer registry breast cancer database. The mean age at diagnosis was 49.2 years (range 30-70). In total, 372 patients were classified as 'low risk', whereas the remaining 777 patients were classified as 'high risk'. After a median follow-up of 11.6 years, the 10-year overall breast cancer-specific survival of the entire DCIS cohort was 1136/1149 (98.9%). Overall breast cancer-specific survival of low risk DCIS was 99.5%, whereas that in high risk DCIS was 98.6% (Log-rank test, P = 0.208). Forty-six (12.4%) patients in the LORIS low risk group did not receive surgery, whereas 93 (12%) patients in the LORIS high risk group did not receive surgery. The 10-year breast cancer-specific survival in the non-operated low risk DCIS group was 97.8%; that in the non-operated high risk DCIS group was 96.7% (P = 1). CONCLUSION: Long-term survival of DCIS was excellent, especially in low risk DCIS, regardless of surgical treatment.
Assuntos
Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Risco Ajustado/métodos , Conduta Expectante/métodos , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Carcinoma Intraductal não Infiltrante/epidemiologia , Carcinoma Intraductal não Infiltrante/patologia , Carcinoma Intraductal não Infiltrante/terapia , Feminino , Hong Kong/epidemiologia , Humanos , Estudos Longitudinais , Mastectomia/métodos , Mastectomia/estatística & dados numéricos , Pessoa de Meia-Idade , Seleção de Pacientes , Sistema de Registros/estatística & dados numéricos , Medição de Risco/estatística & dados numéricos , Análise de SobrevidaRESUMO
Autism spectrum disorders (ASDs) are characterized by impaired learning of social skills and language. Memories of how parents and other social models behave are used to guide behavioral learning. How ASD-linked genes affect the intertwined aspects of observational learning and behavioral imitation is not known. Here, we examine how disrupted expression of the ASD gene FOXP1, which causes severe impairments in speech and language learning, affects the cultural transmission of birdsong between adult and juvenile zebra finches. FoxP1 is widely expressed in striatal-projecting forebrain mirror neurons. Knockdown of FoxP1 in this circuit prevents juvenile birds from forming memories of an adult song model but does not interrupt learning how to vocally imitate a previously memorized song. This selective learning deficit is associated with potent disruptions to experience-dependent structural and synaptic plasticity in mirror neurons. Thus, FoxP1 regulates the ability to form memories essential to the cultural transmission of behavior.
RESUMO
Humanized IgG1 M195 (HuG1-M195), a complementarity determining region-grafted recombinant monoclonal antibody, is reactive with CD33, an antigen expressed on myelogenous leukemia cells. M195 is in use in trials for the therapy of acute myelogenous leukemia. Since biological activity of IgG may depend, in part, on multimeric Fab and Fc clustering, homodimeric forms of HuG1-M195 were constructed by introducing a mutation in the gamma 1 chain CH3 region gene to change a serine to a cysteine, allowing interchain disulfide bond formation at the COOH terminal of the IgG. Despite similar avidity, the homodimeric IgG showed a dramatic improvement in the ability to internalize and retain radioisotope in target leukemia cells. Moreover, homodimers were 100-fold more potent at complement-mediated leukemia cell killing and antibody-dependent cellular cytotoxicity using human effectors. Therefore, genetically engineered multimeric constructs of IgG may have advantages relative to those forms that are found naturally.
Assuntos
Anticorpos Monoclonais/imunologia , Imunoglobulina G/imunologia , Linfócitos/imunologia , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/metabolismo , Citotoxicidade Celular Dependente de Anticorpos , Linhagem Celular , Membrana Celular/imunologia , Citometria de Fluxo , Humanos , Regiões Constantes de Imunoglobulina/genética , Regiões Constantes de Imunoglobulina/imunologia , Fragmentos Fab das Imunoglobulinas/imunologia , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/genética , Imunoglobulina G/metabolismo , Leucemia Promielocítica Aguda , Substâncias Macromoleculares , Mutagênese Sítio-Dirigida , Engenharia de Proteínas , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismoRESUMO
The association of breast implants and anaplastic large cell lymphoma (BIA-ALCL) was first described in 1997. Such an association has aroused public health concerns on breast implant safety. A systematic review was carried out with a pooled analysis of data. In total, 674 non-duplicate articles were retrieved; 77 articles were included for data extraction; 395 patients were identified for analysis. The median age at the time of diagnosis was 52 years. Implant texture was described in 201 (50.9%) patients; all 201 patients had a textured implant. The median time from the last implant insertion to diagnosis was 7.5 years. Most patients presented with seroma (67.1%, n = 265), 20.5% of patients presented with breast mass (n = 81). Patients with a breast mass at presentation, lymphadenopathy and those without seroma had more disseminated disease (P < 0.001). 73.2% of patients (n = 289) opted for primary surgery, among which 68.6% (n = 271) received removal of the implant, 61% (n = 241) received capsulectomy and 2% (n = 8) received mastectomy. Of note, 5.3% (n = 21) had reinsertion of an implant after primary surgery. Non-surgical modalities included chemotherapy, radiotherapy and haematopoietic stem cell transplant. The median follow-up interval was 2 years (range 0-14.5 years). Seventeen patients (4.3%) had recurrence of BIA-ALCL and 195 patients (49.4%) did not. The median duration to first recurrence was 1 year (range 1-3 years). Long-term clinical outcome was not reported in 183 patients. BIA-ALCL is an indolent disease that presents with seroma after implant insertion. A high index of suspicion is needed for early diagnosis and treatment.
Assuntos
Implantes de Mama/efeitos adversos , Neoplasias da Mama/cirurgia , Linfoma Anaplásico de Células Grandes/etiologia , Neoplasias da Mama/patologia , Estudos de Coortes , Feminino , Humanos , Linfoma Anaplásico de Células Grandes/patologia , PrognósticoRESUMO
AIMS: Secondary angiosarcoma is known to be associated with lymphoedema or radiation after cancer treatment. This systematic review aims to evaluate the clinical features and outcomes of secondary angiosarcoma commonly arising after breast cancer treatment. MATERIALS AND METHODS: A systematic review was carried out according to the PRISMA protocol. Medline, EMBASE, CINAHL and Cochrane databases were searched for English articles to April 2018 with predefined strategy. Retrieved studies were independently screened and rated for relevance. Data were extracted by two researchers. RESULTS: There were 72 secondary angiosarcomas of the limbs. Most patients (n = 68, 94.4%) had a history of lymphoedema. The median latent period was 15 years (range 3-40 years). Thirty-eight (52.8%) patients received wide excision or amputation as a treatment for the angiosarcoma, two (2.8%) patients received isolated limb perfusion and one (1.4%) patient received systemic chemotherapy. The remaining patients received palliative care/undocumented treatment. The pooled median duration to mortality was 10.5 months (range 1-144 months). Of note, obesity was documented in seven (9.7%) patients. There were 83 breast angiosarcomas; all with known breast cancer history. Thirty-one (37.3%) patients received mastectomy as breast cancer treatment. Fifty-four (65.1%) patients had a history of adjuvant radiotherapy for the primary breast cancer. The median latent period was 6 years (range 2-50 years); the median size was 40 mm (range 8-200 mm). Forty-one (49.4%) patients received wide excision, 19 (22.9%) patients received completion mastectomy and 23 (27.7%) patients have undocumented treatment for angiosarcoma. The pooled median duration to mortality was 31 months (range 6-168 months). CONCLUSION: Angiosarcoma in lympedematous upper limbs or after breast cancer irradiation remains uncommon. However, its long latency and high mortality warrant long-term vigilant surveillance.
Assuntos
Hemangiossarcoma/etiologia , Linfedema/complicações , Radioterapia Adjuvante/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hemangiossarcoma/patologia , Humanos , Pessoa de Meia-Idade , Adulto JovemRESUMO
By atomic absorption analysis, we determined that the reovirus outer capsid protein sigma 3, which binds double-stranded RNA (dsRNA), is a zinc metalloprotein. Using Northwestern blots and a novel zinc blotting technique, we localized the zinc- and dsRNA-binding activities of sigma 3 to distinct V8 protease-generated fragments. Zinc-binding activity was contained within an amino-terminal fragment that contained a transcription factor IIIA-like zinc-binding sequence, and dsRNA-binding activity was associated with a carboxy-terminal fragment. By these techniques, new zinc- and dsRNA-binding activities were also detected in reovirus core proteins. A sequence similarity was observed between the catalytic site of the picornavirus proteases and the transcription factor IIIA-like zinc-binding site within sigma 3. We suggest that the zinc- and dsRNA-binding activities of sigma 3 may be important for its proposed regulatory effects on viral and host cell transcription and translation.
Assuntos
Proteínas do Capsídeo , Capsídeo/metabolismo , RNA de Cadeia Dupla/metabolismo , Proteínas de Ligação a RNA , Reoviridae/metabolismo , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Eletroforese em Gel de Poliacrilamida/métodos , Dados de Sequência Molecular , Fragmentos de Peptídeos/metabolismo , Peptídeo Hidrolases/metabolismo , Reoviridae/ultraestrutura , Relação Estrutura-Atividade , Zinco/metabolismoRESUMO
The ability to produce monoclonal antibodies (Mabs) in plants offers the opportunity for the development of an inexpensive method of mucosal immunoprotection against sexually transmitted diseases. To investigate the suitability of plant-expressed Mabs for vaginal preventive applications, we compared a humanized anti-herpes simplex virus 2 (HSV-2) Mab expressed in mammalian cell culture with the same antibody expressed in soybean. We found these Mabs to be similar in their stability in human semen and cervical mucus over 24 h, their ability to diffuse in human cervical mucus, and their efficacy for prevention of vaginal HSV-2 infection in the mouse.
Assuntos
Anticorpos Monoclonais/imunologia , Herpes Genital/prevenção & controle , Plantas Geneticamente Modificadas/genética , Vagina/imunologia , Animais , Anticorpos Monoclonais/genética , Modelos Animais de Doenças , Feminino , Herpes Genital/imunologia , Herpesvirus Humano 2/isolamento & purificação , Humanos , Imunidade nas Mucosas , Camundongos , Vagina/virologiaRESUMO
Human-mouse chimeric immunoglobulins G1 and G3 (IgG1 and IgG3) (ChG1, ChG3) and "complementarity-determining region"-grafted, humanized IgG1 and IgG3 (HuG1, HuG3) constructs of the mouse monoclonal antibody (mAb) M195 were characterized. M195 is a murine immunoglobulin G2a (IgG2a), anti-CD33 mAb, specifically reactive with acute myelogenous leukemia cells, that is active as an antileukemia agent in humans. The new mAb constructs maintained specificity and biological function, including rapid internalization after binding to the cell surface, which has been important for delivery of therapeutic isotopes in patients. Although previously reported complementarity-determining region-grafted mAbs had reduced avidities, the HuG1 and HuG3 M195 showed up to an 8.6- and 4-fold higher binding avidity, respectively, than the original murine mAb. All constructs were effective at mediating rabbit complement-mediated cytotoxicity against HL60 targets. Fibroblasts transfected with CD33 genes and expressing high levels of CD33 antigen were also lysed in the presence of human complement, but HL60 cells or fibroblasts with lower CD33 levels were not killed. Thus, the inability of M195 and constructs to kill HL60 targets with human complement is due to the much lower antigen density on HL60 cells compared to CD33+ fibroblasts. Unlike the murine M195, the chimeric and humanized M195 demonstrated antibody-dependent cell-mediated cytotoxicity using human peripheral blood mononuclear cells as effectors. Because the chimeric and humanized M195 have improved avidities as compared to the original M195 and have, in addition, the potential to avoid human anti-mouse antibody responses and to recruit human effector functions, these new constructs may be useful therapeutically, either alone or conjugated to toxins or isotopes, in the treatment of acute myelogenous leukemia.
Assuntos
Anticorpos Monoclonais/imunologia , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Animais , Especificidade de Anticorpos , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Ligação Competitiva , Citotoxicidade Imunológica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Ensaio Radioligante , Lectina 3 Semelhante a Ig de Ligação ao Ácido SiálicoRESUMO
ABL 364 is a murine monoclonal IgG3 antibody directed against the Lewis Y carbohydrate antigen (Le(y)) expressed on the surface of many epithelial cell tumors. The antibody mediates cytotoxicity via activation of human complement or human effector cells, and has been evaluated in several clinical trials including two Phase I/II trials in relapsed small cell lung cancer and metastatic breast cancer. To improve the effector functions of the antibody, increase its half-life in circulation, and avoid the human antimouse antibody response, two chimeric and several humanized antibodies were constructed for evaluation. The chimeric IgG1 is more potent than the murine IgG3 in tumor cell lysis via activation of human peripheral mononuclear cells (10-fold), but somewhat less effective in complement-dependent lysis (2-3 fold). The chimeric IgG3 is slightly less potent than the IgG1. A humanized IgG1 was constructed by combining the complementarity-determining regions of the ABL 364 antibody with human framework and constant regions. Several additional variants were subsequently constructed to improve the binding affinity and increase expression of the antibody. Two of the variants, designated I and K, differ by a single amino acid at position 75 of the heavy chain. Both variants have affinity within 2-fold of the chimeric IgG1 antibody and retain the cytolytic activities toward tumor cell lines. However, it was possible to express variant K at a significantly higher level (5- 10-fold) than variant I. Pharmacokinetics of the humanized ABL 364 antibody variant K was compared with that of the parent murine antibody in rhesus monkeys. It was shown that the terminal half-life of the humanized antibody in rhesus monkeys is 14-20 days, with a mean of 16.3 days, while that of the parent murine antibody is only 1.9 days.
Assuntos
Anticorpos Monoclonais/imunologia , Antígenos do Grupo Sanguíneo de Lewis/imunologia , Proteínas Recombinantes de Fusão/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/farmacocinética , Sequência de Bases , Células Cultivadas , DNA Complementar/genética , Humanos , Ativação Linfocitária , Macaca mulatta , Camundongos , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacocinéticaRESUMO
M195 is a murine monoclonal antibody that binds to the CD33 antigen and is being tested for the treatment of myeloid leukemia. Surprisingly, a complementarity determining region (CDR)-grafted, humanized M195 antibody displayed a several-fold higher binding affinity for the CD33 antigen than the original murine antibody. Here we show that the increase in binding affinity resulted from eliminating an N-linked glycosylation site at residue 73 in the heavy chain variable region in the course of humanization. Re-introducing the glycosylation site in the humanized antibody reduces its binding affinity to that of the murine antibody, while removing the glycosylation site from the murine M195 variable domain increases its affinity. The removal of variable region carbohydrates may provide a method for increasing the affinity of certain monoclonal antibodies with diagnostic and therapeutic potential.
Assuntos
Anticorpos Monoclonais/química , Afinidade de Anticorpos , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Sítios de Ligação de Anticorpos , Glicoproteínas/imunologia , Região Variável de Imunoglobulina/química , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/imunologia , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico , Relação Estrutura-AtividadeRESUMO
Antireceptor antibodies have been developed as a probe to study the cellular receptor for reovirus type 3. Using this probe, a glycoprotein with a molecular weight of 65-67 kilodaltons and a pI of 5.8-6.0 was isolated and identified as the reovirus receptor. This protein was also structurally similar to the affinity-purified beta-adrenergic receptor from calf lung. In this report, we employ [125I]-iodocyanopindolol, a high affinity beta-adrenergic antagonist, to further characterize this protein. We show that R1.1, a murine thymoma cell line, possesses about 2,000 receptors per cell with high affinity for ICYP (kD = 3.3 X 10(-11) M). Competitive inhibition studies suggest that the receptor is of the beta-2 subtype. Solubilized receptor proteins from R1.1 cells bound to the antireceptor antibody were further purified by SDS-PAGE and electroelution from the gel. Five percent of the proteins thus obtained could bind ICYP with high affinity (kD = 1.6 X 10(-10) M). This suggests that the purification procedure produced a collection of forms of this 65- to 67-kilodalton protein, some of which retained the conformation for binding the beta ligands. We also demonstrate that the isolated receptor protein was able to bind ICYP even when the virus binding site was occupied by the anti-idiotype, suggesting that reovirus type 3 and the beta ligands bind to distinct domains on the receptor protein.
Assuntos
Agonistas Adrenérgicos beta/metabolismo , Orthoreovirus Mamífero 3/metabolismo , Pindolol/análogos & derivados , Receptores Adrenérgicos beta/análise , Receptores Virais/análise , Reoviridae/metabolismo , Animais , Sítios de Ligação de Anticorpos , Linhagem Celular , Idiótipos de Imunoglobulinas/imunologia , Radioisótopos do Iodo , Iodocianopindolol , Camundongos , Pindolol/metabolismo , Receptores Adrenérgicos beta/imunologia , Receptores Adrenérgicos beta/isolamento & purificação , Receptores Virais/imunologia , Receptores Virais/isolamento & purificação , Timoma/metabolismoRESUMO
1-(2'-Deoxy-2'-fluoro-beta-L-arabinofuranosyl)-5-methyluracil (L-FMAU) was shown to have potent antiviral activity against Epstein-Barr virus (EBV) without any cellular toxicity at concentrations up to 200 microM (Yao et al., Biochem Pharmacol 51: 941-947, 1996). The 5'-triphosphate of L-FMAU was not a substrate for EBV or cellular DNA polymerases, but could inhibit the elongation reaction, 3'-to-5' exonuclease activity, and nucleotide turnover catalyzed by EBV DNA polymerase. DNA synthesis catalyzed by human DNA polymerases was inhibited to a lesser extent. The inhibition pattern of EBV DNA polymerase by L-FMAU-5'-triphosphate (L-FMAU-TP) was consistent with an uncompetitive mechanism when dNTP or template-primer were used as the variable substrates. The Ki values were 38+/-10 microM for the elongation reaction, and about 50+/-10 microM for both nucleotide exchange and 3'-to-5' exonuclease reactions, values that were 10-20 times less than that for GMP. L-FMAU-TP is the first nucleoside 5'-triphosphate shown to have such unique behavior toward DNA polymerases. EBV DNA polymerase could be one of the targets for the inhibitory effect of L-FMAU-TP on EBV replication.
Assuntos
Antivirais/farmacologia , Arabinofuranosilcitosina Trifosfato/análogos & derivados , Proteínas de Ligação a DNA , Herpesvirus Humano 4/efeitos dos fármacos , Inibidores da Síntese de Ácido Nucleico , Proteínas Virais , Arabinofuranosilcitosina Trifosfato/metabolismo , Arabinofuranosilcitosina Trifosfato/farmacologia , Linhagem Celular , Replicação do DNA/efeitos dos fármacos , DNA Polimerase Dirigida por DNA , Exodesoxirribonuclease V , Exodesoxirribonucleases/antagonistas & inibidores , Exonucleases/antagonistas & inibidores , Humanos , Especificidade por Substrato , Células Tumorais CultivadasRESUMO
Characterization of monoclonal antibodies (MAbs) produced for therapeutic or diagnostic purposes increasingly includes an assessment of their carbohydrate content. Using high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC/PAD), we have analyzed the PNGase F released oligosaccharides of several IgG preparations including human polyclonal IgG, a humanized monoclonal IgG (MAb M115), and a murine monoclonal IgG (MAb MY9-6) derived respectively from serum, hybridoma cultures, and ascites fluid. The N-linked oligosaccharides released by PNGase F treatment of the above IgGs were found to consist mainly of neutral, fucosylated, biantennary species. Comparison of glycosylation of human polyclonal IgG, MAb M115, and MAb MY9-6 revealed differences in the levels of galactosylation and in the levels as well as the form of sialic acid present. HPAEC/PAD oligosaccharide profiling, combined with the use of enzymes (PNGase F, endoglycosidase F2, endoglycosidase H, neuraminidase, beta-galactosidase, and beta-N-acetylhexosaminidase), and monosaccharide analysis allowed making of tentative structural assignments. By performing monosaccharide analysis directly on PVDF electroblotted heavy and light chain bands separated by SDS-PAGE, it was verified that IgGs used in this study were glycosylated predominantly in their heavy chain.
Assuntos
Anticorpos Monoclonais/análise , Carboidratos/análise , Imunoglobulina G/análise , Amidoidrolases/metabolismo , Sequência de Carboidratos , Química Farmacêutica , Cromatografia por Troca Iônica , Eletroquímica , Glicoproteínas/análise , Glicoproteínas/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosilação , Dados de Sequência Molecular , Oligossacarídeos/análise , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina AmidaseRESUMO
BACKGROUND: After decades of decreasing incidence, the number of new tuberculosis cases started to rise again in the mid-1980s and continues to be a major public health problem in the United States. The incidence of tuberculosis and drug-resistant tuberculosis is increasing among persons infected with human immunodeficiency virus. OBJECTIVE: To review the epidemiology, pathogenesis, clinical presentation, diagnosis, drug therapy, patients' nonadherence to prescribed treatment, and nursing issues related to the care of persons dually infected with tuberculosis and human immunodeficiency virus. METHODS: Fifty references addressing important issues in tuberculosis and human immunodeficiency virus were identified by searching the Medline data base and bibliographies of relevant articles. DISCUSSION: Tuberculosis is a communicable infectious disease caused by Mycobacterium tuberculosis. It is curable and preventable but generally fatal if undiagnosed and untreated. People with human immunodeficiency virus infection are at higher risk for reactivation of latent tuberculosis infection and for developing life-threatening tuberculosis. Specific nursing interventions are formulated to guide practice when caring for HIV-infected persons with tuberculosis. Future nursing research needs are suggested. CONCLUSIONS: An understanding of the complexity of the care involved will enhance the clinical management of tuberculosis in human immunodeficiency virus-infected patients and lead to a decline in the appearance of new drug-resistant tuberculosis strains.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/etiologia , Infecções Oportunistas Relacionadas com a AIDS/terapia , Antituberculosos/uso terapêutico , Humanos , Incidência , Controle de Infecções , Mycobacterium tuberculosis/efeitos dos fármacos , Pesquisa em Enfermagem , Fatores de Risco , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/etiologia , Tuberculose Resistente a Múltiplos Medicamentos/terapia , Estados Unidos/epidemiologiaRESUMO
The Philippines is currently the world's leading supplier of seafarers aboard foreign vessels, accounting for nearly a quarter of the world's maritime industry. Seafarers, being mobile, have a significant contribution impact on the worldwide spread of infectious diseases such as sexually transmitted infections (STIs). This study aims to determine the level of knowledge, as well as the attitudes and practices (KAP) of male Filipino seafarers regarding sexual health. A cross-sectional survey was administered through convenience sampling of male Filipino seafarers. The respondents showed the least knowledge about prevention, followed by transmission of STIs. The respondents showed adequate knowledge about risk factors such as multiple sex partners, and about transmission such as vertical spread. In addition, the respondents indicated their attitude and level of responsibility in informing their sexual partners in case they contract STIs and avoidance of high-risk partners. They also showed attitudes that predispose them to high-risk behaviour such as decreased sexual sensation caused by use of condoms and added pleasure in having intercourse with strangers. The majority of respondents were sexually active. Most have STI/HIV screening as part of their pre-employment medical exam. Positive practices include use of condoms, voluntary medical evaluation for STI's, and avoidance of high-risk partners. Negative practices include going to bars closely linked with prostitution, and most of the respondents had had sexual intercourse with sex workers overseas. Male seafarers appear to have double standards regarding women as sexual partners - about half had intercourse outside their stable relationships. They perceive protection as their sole discretion.