RESUMO
Cell saver blood is used within the peri-operative setting of cardiothoracic surgery to reduce the need for transfusion of allogenic blood products. Several meta-analyses have proven a significant decrease in allogenic transfusion with the use of cell salvage techniques. Washing of red cells by the cell saver and subsequent transfusion of suspended red cells can occasionally cause coagulopathy, particularly when using high concentration heparin saline to wash the spilled blood. We present the case of a 74-year-old female who underwent complicated aortic surgery and was transfused large volumes of cell-saved blood due to post-operative bleeding, which subsequently led to coagulopathy.
Assuntos
Doenças da Aorta/cirurgia , Transtornos da Coagulação Sanguínea/etiologia , Recuperação de Sangue Operatório/efeitos adversos , Hemorragia Pós-Operatória/prevenção & controle , Idoso , Transtornos da Coagulação Sanguínea/diagnóstico , Evolução Fatal , Feminino , Humanos , Recuperação de Sangue Operatório/métodosRESUMO
The polypeptide component of telomerase (TERT) is an attractive candidate for a broadly expressed tumor rejection antigen because telomerase is silent in normal tissues but is reactivated in more than 85% of cancers. Here we show that immunization against TERT induces immunity against tumors of unrelated origin. Immunization of mice with TERT RNA-transfected dendritic cells (DC) stimulated cytotoxic T lymphocytes (CTL), which lysed melanoma and thymoma tumor cells and inhibited the growth of three unrelated tumors in mice of distinct genetic backgrounds. TERT RNA-transfected human DC stimulated TERT-specific CTL in vitro that lysed human tumor cells, including Epstein Barr virus (EBV)-transformed B cells as well as autologous tumor targets from patients with renal and prostate cancer. Tumor RNA-transfected DC were used as surrogate targets in the CTL assays, obviating the difficulties in obtaining tumor cells from cancer patients. In one instance, where a tumor cell line was successfully established in culture from a patient with renal cancer, the patient's tumor cells were efficiently lysed by the CTL. Immunization with tumor RNA was generally more effective than immunization with TERT RNA, suggesting that an optimal immunization protocol may have to include TERT as well as additional tumor antigens.
Assuntos
Vacinas Anticâncer/uso terapêutico , Células Dendríticas/imunologia , Neoplasias Experimentais/prevenção & controle , Linfócitos T Citotóxicos , Telomerase/uso terapêutico , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/uso terapêutico , Linfócitos B , Transformação Celular Viral , Antígenos H-2 , Herpesvirus Humano 4 , Humanos , Imunoterapia , Neoplasias Renais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Neoplasias da Próstata/imunologia , RNA/genética , RNA/imunologia , RNA/uso terapêutico , Telomerase/genética , Telomerase/imunologia , Vacinas Sintéticas/uso terapêuticoRESUMO
Anaemia is increasingly prevalent in the United Kingdom. Despite recommendations to the contrary, many patients undergo cardiac surgery with undiagnosed and untreated anaemia. According to the World Health Organization definition, 1463/2688 (54.4%) patients undergoing cardiac surgery between 2008 and 2009 in our institution were anaemic. Compared with non-anaemic patients, anaemia was significantly associated with transfusion (791 (54.1%) vs 275 (22.4%), p < 0.001, OR (95% CI) 3.4 (2.8-4.1)), death (45 (3.1%) vs 13 (1.1%), p = 0.0005, OR 2.4 (1.2-4.5)), and prolonged ICU stay (287 (19.6%) vs 168 (13.7%) p < 0.001, OR 1.3 (1.0-1.6)). The prevalence of anaemia in this cohort is much greater than that previously reported. The cause of this excess is not clear. Pre-operative anaemia is a strong predictor of increased transfusion requirement, risk of ICU stay and death during cardiac surgery. The effect of increasing haemoglobin concentration therapeutically is not yet clear.
Assuntos
Anemia/epidemiologia , Procedimentos Cirúrgicos Cardíacos/mortalidade , Transfusão de Eritrócitos , Unidades de Terapia Intensiva , Tempo de Internação , Idoso , Anemia/terapia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , PrevalênciaRESUMO
Immunization with defined tumor antigens is currently limited to a small number of cancers where candidates for tumor rejection antigens have been identified. In this study we investigated whether pulsing dendritic cells (DC) with tumor-derived RNA is an effective way to induce CTL and tumor immunity. DC pulsed with in vitro synthesized chicken ovalbumin (OVA) RNA were more effective than OVA peptide-pulsed DC in stimulating primary, OVA-specific CTL responses in vitro. DC pulsed with unfractionated RNA (total or polyA+) from OVA-expressing tumor cells were as effective as DC pulsed with OVA peptide at stimulating CTL responses. Induction of OVA-specific CTL was abrogated when polyA+ RNA from OVA-expressing cells was treated with an OVA-specific antisense oligodeoxynucleotide and RNase H, showing that sensitization of DC was indeed mediated by OVA RNA. Mice vaccinated with DC pulsed with RNA from OVA-expressing tumor cells were protected against a challenge with OVA-expressing tumor cells. In the poorly immunogenic, highly metastatic, B16/F10.9 tumor model a dramatic reduction in lung metastases was observed in mice vaccinated with DC pulsed with tumor-derived RNA (total or polyA+, but not polyA- RNA). The finding that RNA transcribed in vitro from cDNA cloned in a bacterial plasmid was highly effective in sensitizing DC shows that amplification of the antigenic content from a small number of tumor cells is feasible, thus expanding the potential use of RNA-pulsed DC-based vaccines for patients bearing very small, possibly microscopic, tumors.
Assuntos
Células Apresentadoras de Antígenos/fisiologia , Células Dendríticas/imunologia , RNA/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Sequência de Bases , Citotoxicidade Imunológica , Imunidade Celular , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Ovalbumina/genética , Ovalbumina/imunologia , RNA Mensageiro/genética , RNA Mensageiro/imunologiaRESUMO
OBJECTIVE: To find out the type of bacteria colonising the tracheostomy tube and to determine the antibiotic sensitivity pattern and resistance in patients who have had tracheostomy in intensive care unit (ICU) set up and to initiate proper empirical treatment in such patients. METHODS: The study was a retrospective review of patients who underwent tracheostomy at Ministry of Health, Sur Hospital, Oman January 2005 and December 2015. The Hospital has 4 bedded pediatric intensive care unit (PICU) and 10 bedded adult ICU which is headed by consultant anaesthetists, consultant physicians, ICU trained nurses and respiratory therapists. All patients who required mechanical ventilation and were therefore subject to an orotracheal intubation and those who underwent a conventional tracheostomy were considered for inclusion. Patients who had been intubated in other hospitals or ICUs, other airways infection issues were excluded from this study. Data's were collected from computer based hospital management system, operation theatre and registers in Medical records department and entered in a preformed questionnaire before thorough analysis. The specimens for swab was obtained from the cut tracheostomy tube tips and the samples were sent to microbiology laboratory for isolation of the organism and obtain an antibiogram to know the susceptibility and resistance to antibiotics. Data were analyzed by Statistical Package for Social Sciences (SPSS, version 16, Chicago, Inc) and the values are reported as number (%). The commonest isolated organism was Pseudomonas followed by Acinetobacter. RESULTS: During the ten year retrospective study, there were 108 patients included in our study with 56 males and 51 females. Fourteen different microorganisms were isolated during our study which included Pseudomonas aeruginosa (n = 39), Acinetobacter baumanii (n = 28), Klebsiella (n = 10) and coagulase negative staphylococcus (n = 6). The most commonest organisms in both genders was Pseudomonas aeruginosa closely followed by Acinetobacter baumanii. In children under age of 12, it was Pseudomonas aeruginosa and in adults the impending organism was Acinetobacter baumanii. In terms of antiobiograms, 89% of Acinetobacter, 38% of Staphylococcus aureus, 37% of Klebsiella and 54% of Proteus mirabilis were resistant to ciprofloxacin. These organisms were resistant to ceftazidime in 97%, 83%, 89% and 57% of the cases, respectively and resistant to imipenem in 7.4%, 18.2%, 1.8% and 8.1%. CONCLUSIONS: In summary, this study presents the most common microorganisms colonized from tracheostomy of hospitalized patients and their pattern of antibiotic resistance. As our study showed, Pseudomonas is the most common microorganism isolated from tracheostomy tube. Ciprofloxacin was also the most prevalent antibiotic revealing resistant pattern. Moreover, most of the microorganisms were sensitive to imipenem and pipracillin-tazobactam.
RESUMO
BACKGROUND: Given improvements in multimodality therapy, survival among children with Wilms tumor (WT) exceeds 90%. However, 15% of children with favorable histology and 50% of children with anaplastic WT experience recurrence or progression. Of patients with advanced disease, only 50% survive to adulthood. In adult malignancies (including renal tumors), patient survival has improved with the advent of immunotherapy. However, little is known about the immune microenvironment of WT, making the potential role of immunotherapy unclear. OBJECTIVE: The objective of the study is to perform an exploratory, descriptive analysis of the immune milieu in WT. STUDY DESIGN: Between 2016 and 2017, all pediatric patients with WT, some of whom received neoadjuvant chemotherapy, underwent ex vivo wedge biopsy at the time of nephrectomy. The fresh tumor tissue and peripheral blood samples were analyzed for infiltrating immune infiltrate and effector cells using flow cytometry. Immunohistochemistry was performed for CD4, CD8, and PD-L1 expression. Matched blood samples were obtained for each patient, and circulating immune cells were analyzed by flow cytometry. RESULTS: A total of six patients were enrolled. One patient with neuroblastoma was excluded. The remaining five patients included the following: two with unilateral WT (resected before chemotherapy), two with bilateral WT (resected after neoadjuvant chemotherapy), and one with Denys-Drash syndrome, end-stage renal disease, and history of WT in the contralateral kidney. Immune analysis showed that WT were infiltrated by immune cells regardless of chemotherapy status. CD8 and CD4 T cells were present in the tumor tissue and exhibited an activated phenotype. Elevated levels of natural killer (NK) cells were observed in the tumors (Figure). Immune checkpoint PD-L1 was also found expressed in one of the tumors stained. DISCUSSION: In this pilot study, it was found that WTs were infiltrated by immune cells (CD45+) both before and after chemotherapy. Elevated levels of NK cells infiltrating the tumor specimens, which were quantitatively increased compared with levels of NK cells circulating in the blood, were noted. T cells, particularly CD4+ and CD8+ T cells, were present in tumor specimens. Tumor-infiltrating CD4 and CD8 T cells displayed an activated phenotype as defined by increased expression of human leukocyte antigen-DR isotype (HLA-DR), programmed cell death protein 1 (PD1), and CD57. Together, these findings suggest that WT microenvironment is immune engaged and may be susceptible to immunotherapy similar to other malignancies. CONCLUSIONS: These pilot data suggest an immune-engaged tumor microenvironment is present within WT. This implies that WT may be susceptible to immunotherapy similar to adult renal tumors and other adult malignancies. Follow-up studies are currently underway.
Assuntos
Antígenos CD/imunologia , Imunidade Celular , Imunoterapia/métodos , Neoplasias Renais/imunologia , Linfócitos T/imunologia , Tumor de Wilms/imunologia , Antígenos CD/metabolismo , Biomarcadores Tumorais/metabolismo , Relação CD4-CD8 , Pré-Escolar , Feminino , Seguimentos , Humanos , Neoplasias Renais/diagnóstico , Neoplasias Renais/terapia , Masculino , Projetos Piloto , Prognóstico , Estudos Retrospectivos , Tumor de Wilms/diagnóstico , Tumor de Wilms/terapiaRESUMO
BACKGROUND AND OBJECTIVES: An auricular pseudocyst is not uncommon in routine ENT clinical practice, it occurs when fluid accumulates between the intracartilaginous spaces of the auricle. Many treatment modalities have been proposed such as incision and drainage of the cyst, simple needle aspiration, tight bandaging with dental rolls, however recurrence and cosmetic problems are still noted in some cases. The aim of this article was to discuss our experience of surgical treatment of intractable auricular pseudocysts with marsupialisation, deroofing and anterior cartilage leaflet removal along with compression suture therapy. MATERIALS AND METHODS: Twenty patients were included in the study conducted at ENT department, Sur Ministry of Health Hospital between January 2012 and January 2014 after prior consent and ethical approval. Those following trauma and other pinna conditions like relapsing polychondritis were excluded from our study. The clinical appearances were noted and all patients underwent surgical deroofing with removal of anterior cartilage leaflet and compression suture therapy using buttons for two weeks. RESULTS AND OBSERVATIONS: There were 8 males and 12 females out of the 20 and right sided pinna (n = 14) involvement in the region of the scaphoid fossa (n = 12) was more than the triangular fossa (n = 3) or conchal bowl involvement (n = 5). Mostly patients between 30 and 40 years of age were affected (Mean age of 37 years and standard deviation of 8). The overall success rate with deroofing and compression suture therapy was 98%. CONCLUSIONS: Auricular pseudocysts are not an uncommon condition affecting middle aged patients without identifiable etiology. Conservative modalities may be the first choice of treatment for auricular pseudocysts although varied recurrence and failure rates have been published in the literature. However, the deroofing surgical technique with anterior cartilage leaflet removal with compression suture therapy is a reliable and easy procedure which can achieve an acceptable appearance of the pinna without recurrence when conservative management fails or is refused by the patient.
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Recently determined structures of a number of Myc family proteins have provided significant insights into the molecular nature of complex assembly and DNA binding. These structures illuminate the details of specific interactions that govern the assembly of nucleoprotein complexes and, in doing so, raise more questions regarding Myc biology. In this review, we focus on the lessons provided by these structures toward understanding (1) interactions that govern transcriptional repression by Mad via the Sin3 pathway, (2) homodimerization of Max, (3) heterodimerization of Myc-Max and Mad-Max, and (4) DNA recognition by each of the Max-Max, Myc-Max, and Mad-Max dimers.
Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/química , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/química , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas Proto-Oncogênicas c-myc/química , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , DNA/química , DNA/genética , DNA/metabolismo , Dimerização , Genes myc , Humanos , Modelos Moleculares , Estrutura Molecular , Complexos Multiproteicos , Mutação , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Repressoras/genéticaRESUMO
Dendritic cells (DC) generated from the peripheral blood mononuclear cells of healthy individuals or from cancer patients transfected with carcinoembryonic antigen (CEA) mRNA stimulate a potent CD8+ cytotoxic T lymphocyte (CTL) response in vitro. DCs are effectively sensitized with RNA in the absence of reagents commonly used to facilitate mammalian cell transfection. RNA encoding a chimeric CEA/LAMP-1 lysosomal targeting signal enhances the induction of CEA-specific CD4+ T cells, providing a strategy to induce T-help that may be necessary to generate and/or maintain an optimal CD8+ CTL response in vivo. CEA RNA-transfected DCs also serve as effective targets in cytotoxicity assays, thus providing a general method for inducing, as well as measuring, CEA-specific CTL responses across a broad spectrum of HLA haplotypes.
Assuntos
Antígeno Carcinoembrionário/imunologia , Células Dendríticas/metabolismo , RNA/genética , Linfócitos T Citotóxicos/imunologia , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Antígeno Carcinoembrionário/genética , Linhagem Celular , Neoplasias do Colo/imunologia , Neoplasias do Colo/patologia , Células Dendríticas/imunologia , Humanos , Metástase Neoplásica/imunologia , Transfecção , Células Tumorais CultivadasRESUMO
OBJECTIVES: To determine the cataract surgical coverage, utilization and barriers to cataract surgery in a rural taluk of south India. STUDY DESIGN: A cross-sectional, community-based survey. METHODS: A house-to-house survey was carried out in 15 villages that were selected by cluster sampling during January to October, 2002. A total of 1505 people aged 50 years and above were tested for visual acuity (VA) and their eyes examined. Cataract surgical coverage was calculated for people and eyes, and for VA levels of <3/60 and <6/60. Information about details of cataract surgery and barriers to cataract surgery were collected using a pre-designed proforma. RESULTS: Cataract surgical coverage was 63% (people) and 51% (eyes) for VA<3/60 compared with 49% (people) and 36% (eyes) for VA<6/60. Of 109 operated eyes, 51.2% of operations were carried out in private hospitals and 33.3% in voluntary/charitable hospitals. Inability to afford the operation (22.9%) and fear of the operation (19.2%) were the main barriers to cataract surgery. CONCLUSIONS: The reasons for underutilization of government hospitals are to be investigated. Awareness of low-cost cataract intraocular lens (IOL) non-governmental organization (NGO) surgery and free-of-cost NGO services available in the region needs to be raised. Barriers to cataract surgical services should be addressed by community-based health-education programmes to improve the uptake of existing services.
Assuntos
Extração de Catarata/estatística & dados numéricos , Catarata/epidemiologia , Acessibilidade aos Serviços de Saúde/economia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Serviços de Saúde Rural/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Catarata/diagnóstico , Extração de Catarata/economia , Análise por Conglomerados , Estudos Transversais , Feminino , Custos de Cuidados de Saúde , Pesquisas sobre Atenção à Saúde , Hospitais com Fins Lucrativos/economia , Hospitais com Fins Lucrativos/estatística & dados numéricos , Hospitais Públicos/economia , Hospitais Públicos/estatística & dados numéricos , Hospitais Filantrópicos/economia , Hospitais Filantrópicos/estatística & dados numéricos , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Prevalência , Serviços de Saúde Rural/classificação , Serviços de Saúde Rural/economia , Seleção Visual , Acuidade VisualRESUMO
To estimate the prevalence of blindness and its causes among those aged 50 years and above in rural Karnataka. A total of 1505 people aged 50 years and above from 15 villages were examined. The participants were selected through a house-to-house survey by the cluster sampling method. Visual acuity was tested using a modified Snellen's chart, and eyes were examined to ascertain the cause of blindness. The prevalence of blindness was 6.6% (95% confidence interval: 5.3-7.8%). Bilateral cataract was the principal cause of blindness among 78.7% of the blind and 12.1% were operated for cataract. In conclusion, the study area has a high burden of cataract blindness. Cataract surgical services should be made readily accessible and available to this rural population.
Assuntos
Cegueira/epidemiologia , Idoso , Cegueira/etiologia , Cegueira/prevenção & controle , Catarata/complicações , Técnicas de Diagnóstico Oftalmológico , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Saúde da População Rural , Acuidade VisualRESUMO
Unique patient-specific tumor antigens may constitute the dominant antigens in the antitumor immune response. Hence, vaccination with the patient's own repertoire of tumor antigens may offer a superior strategy to elicit protective immunity. We have shown previously that dendritic cells transfected with mRNA isolated from tumor cells stimulate potent CTL responses and engender protective immunity in tumor-bearing mice. In the current study, we demonstrate that tumor mRNA, isolated from murine tumor cell lines or from primary human tumor cells microdissected from frozen tissue sections, can be amplified without loss of function. This study provides the foundations for an effective and broadly applicable treatment that does not require the characterization of the relevant antigenic profile in each patient and will not be limited by tumor tissue availability for antigen preparation.
Assuntos
Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , RNA Mensageiro/imunologia , RNA Neoplásico/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , VacinaçãoRESUMO
Dendritic cells (DCs), matured by CD40-ligand (CD40L), undergo marked changes in their ability to process and present antigen, resulting in augmented lymphocyte stimulatory activity. We demonstrate that the form of the tumor antigen (peptide or genetic material) used to load the DCs dictates the required sequence of antigen loading and maturation for antitumor immunotherapy. Optimal stimulation of carcinoembryonic antigen (CEA)-specific CTLs by peptide-loaded DCs occurs when DCs from cancer patients are matured with CD40L before exposure to CEA peptide, whereas optimal stimulation by RNA-transfected DCs occurs when the DCs are loaded with CEA RNA before maturation with CD40L.
Assuntos
Antígenos CD40/imunologia , Antígeno Carcinoembrionário/imunologia , Células Dendríticas/imunologia , Glicoproteínas de Membrana/farmacologia , Antígenos CD40/fisiologia , Ligante de CD40 , Antígeno Carcinoembrionário/fisiologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/fisiologia , Humanos , Ligantes , Ativação Linfocitária , RNA Mensageiro/metabolismo , TransfecçãoRESUMO
Estrogen receptors (ER alpha and ER beta) are ligand-activated nuclear receptors that mediate the action of estrogens. These receptors activate transcription by similar mechanism(s), although the overall amino acid sequence identity is only 47%. In order to compare the structural and conformational features of ER alpha and ER beta, we monitored their intrinsic tryptophan fluorescence during thermal unfolding. The 50% unfolding temperatures (T(M)) of ER alpha and ER beta were 39+/-1 and 40+/-2 degrees C, respectively. Estradiol had no significant effect on the T(M) of ER alpha or ER beta. In contrast, binding of the estrogen-response element increased the T(M) of ER alpha and ER beta by 10 degrees C. Thermal unfolding of estradiol-bound ER alpha and ligand-free ER beta showed two-step transitions, with the formation of intermediates that were stable between 36-48 and 34-42 degrees C, respectively. We confirmed the presence of intermediate states during thermal unfolding by circular dichroism spectroscopy. Atomic force microscopy showed that the ER beta intermediate consisted of discrete globular particles, whereas the ER alpha intermediate showed a speckled appearance, with sparse well-defined particles. Fluorescence-quenching studies showed the presence of two classes of tryptophan in unliganded ER alpha and ER beta. Binding of estradiol to ER beta exposed its tryptophans, whereas estradiol reduced the accessibility of the tryptophans of ER alpha. Our results illustrate the differential effects of ligands on the unfolding of ER alpha and ER beta, and identify partially unfolded intermediates. Differences in the conformational flexibility and stability of ER alpha and ER beta may represent functional differences of ligand-bound ERs in recruiting coactivator proteins and initiating transcription.
Assuntos
Receptor alfa de Estrogênio/química , Receptor beta de Estrogênio/química , Conformação Proteica , Triptofano/química , Acrilamida/química , Dicroísmo Circular , Estradiol/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Feminino , Humanos , Masculino , Microscopia de Força Atômica , Tamanho da Partícula , Desnaturação Proteica , Dobramento de Proteína , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genéticaRESUMO
We have developed a novel liposome-mediated immunogene therapy using interleukin 2 (IL-2) and B7.1 in a murine bladder cancer model. A carcinogen-induced murine bladder cancer cell line, MBT-2, was transfected with cationic liposome 1,2-dimyristyloxypropyl-3-dimethyl-hydroxyethyl ammonium bromide/dioleolylphosphatidylethanolamine and IL-2 plasmid. The optimized transfection condition generated IL-2 levels of 245-305 ng/10(6) cells/24 h, 100-fold higher than the levels seen with retrovirus transfection. Ninety percent of the peak level of IL-2 production was maintained for up to 11 days after transfection. Animal studies were conducted in C3H/HeJ female mice with 2 x 10(4) MBT-2 cells implanted orthotopically on day 0. Multiple vaccination schedules were performed with i.p. injection of 5 x 10(6) IL-2 and/or B7.1 gene-modified cell preparations. The greatest impact on survival was observed with the day 5, 10, and 15 regimen. Control animals receiving retrovirally gene-modified MBT-2/IL-2 cell preparations had a median survival of 29 days. Animals receiving the IL-2 liposomally gene-modified cell preparation alone had a median survival of 46 days. Seventy-five percent of animals receiving IL-2 followed by B7.1 gene-modified tumor vaccines were the only group to show complete tumor-free survival at day 60. All of these surviving animals rejected the parental MBT-2 tumor rechallenge and survived at day 120 with a high CTL response. In conclusion, liposome-mediated transfection demonstrates a clear advantage as compared with the retroviral system in the MBT-2 model. Multi-agent as opposed to single-agent cytokine gene-modified tumor vaccines were beneficial. These "targeted" sequential vaccinations using IL-2 followed by B7.1 gene-modified tumor cells significantly increased a systemic immune response that translated into increased survival.
Assuntos
Antígeno B7-1/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Terapia Genética/métodos , Interleucina-2/genética , Fosfatidiletanolaminas , Neoplasias da Bexiga Urinária/terapia , Animais , Terapia Combinada , Intervalo Livre de Doença , Esquema de Medicação , Portadores de Fármacos , Feminino , Glicerofosfolipídeos , Interleucina-2/uso terapêutico , Lipídeos , Lipossomos , Camundongos , Camundongos Endogâmicos C3H , Compostos de Amônio Quaternário , Proteínas Recombinantes/genética , Proteínas Recombinantes/uso terapêutico , Linfócitos T Citotóxicos/imunologia , Transfecção/métodos , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/imunologiaRESUMO
Immunization with dendritic cells loaded with tumor antigens could represent a powerful method of inducing antitumor immunity. Studies from several laboratories have shown that immunization with dendritic cells pulsed with specific antigens prime cytotoxic T-cells and engender tumor immunity. This review will focus on the use of dendritic cells transfected with RNA as cancer vaccines, with emphasis on the potential advantages of using RNA. The majority of cancer patients who lack an identified tumor antigen and/or cannot provide sufficient tumor tissue for antigen preparation will be excluded from treatment with cancer vaccines based on using either specific tumor antigens or mixtures of tumor-derived antigens in the form of peptides or proteins isolated from tumor cells. Vaccination with the mRNA content of tumor cells would extend the scope of vaccination to this group of patients as well because RNA can be amplified from very few cancer cells.
Assuntos
Vacinas Anticâncer/administração & dosagem , Células Dendríticas/imunologia , RNA/genética , Transfecção , Animais , Antígenos de Neoplasias/administração & dosagem , Vacinas Anticâncer/genética , DNA/genética , Técnicas de Transferência de Genes , Humanos , Imunoterapia/métodos , Imunoterapia/tendências , Neoplasias/imunologia , Neoplasias/terapia , RNA Mensageiro/genética , RNA Neoplásico/genéticaRESUMO
[see structure]. An efficient, concise approach to the macrolide core of the cryptophycins, potent antimitotic agents, has been achieved. The reaction sequence features a novel macrolactonization utilizing a reactive acyl-beta-lactam intermediate that incorporates the beta-amino acid moiety within the 16-membered macrolide core. This highly modular approach, which allows for multiple alterations throughout the structure, was successfully applied to the total synthesis of cryptophycin-24.
Assuntos
Peptídeos Cíclicos/síntese química , beta-Lactamas/química , Depsipeptídeos , Mitose/efeitos dos fármacos , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologiaRESUMO
Unlike in many communication channels, the read signals in thin-film magnetic recording channels are corrupted by non-Gaussian, data-dependent noise and nonlinear distortions. In this work we use feedforward neural networks-a multilayer perceptron and its simplified variations-to equalize these signals. We demonstrate that they improve the performance of data recovery schemes in comparison with conventional equalizers. The variations of the MLP equalizer are suitable for the low complexity VLSI implementation required in data storage systems. We also present a novel training criterion designed to reduce the probability of error for the recovered digital data. The results were obtained both from experimental data and from a software recording channel simulator using thin-film disk and magnetoresistive head models.
RESUMO
We present methods to systematically design a feedforward neural-network detector from the knowledge of the channel characteristics. Its performance is compared with the conventional linear equalizer in a magnetic recording channel suffering from signal-dependent noise and nonlinear intersymbol interference. The superiority of the nonlinear schemes are clearly observed in all cases studied, especially in the presence of severe nonlinearity and noise. We also show that the decision boundaries formed by a theoretically derived neural-network classifier are geometrically close to those of a neural network trained by the backpropagation algorithm. The approach in this work is suitable for quantifying the gain in using a neural-network method as opposed to linear methods in the classification of noisy patterns.
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The surgical management of a case of right aortic arch with isolation of the left subclavian artery and bilateral patent ductus arterioses is described. A review of the 39 cases of isolation of the left subclavian artery reported in the literature revealed only one single case which on autopsy was found to have associated bilateral ductus arterioses. The case we report is the first in which the diagnosis was made during life and successful surgical correction was carried out.