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1.
Artigo em Inglês | MEDLINE | ID: mdl-32426703

RESUMO

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.

2.
J Pediatr Urol ; 15(5): 441.e1-441.e8, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30981637

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/terapia
3.
Artigo em Inglês | MEDLINE | ID: mdl-30564784

RESUMO

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.

4.
Perfusion ; 27(1): 30-3, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21859788

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/métodos
5.
Anaesthesia ; 66(9): 812-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21790520

RESUMO

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 , Prevalência
6.
Theor Appl Genet ; 118(4): 643-52, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19034412

RESUMO

Yield losses caused by lodging in cereals can be partially controlled by reducing plant height. A progeny of recombinant inbred lines from a cross of two Japanese barley varieties was used to study the inheritance of culm and culm internode lengths. An unexpected QTL for reduced culm length (qCUL), which affected mainly the length of the third and fourth culm internodes, was contributed by 'Kanto Nakate Gold'. This QTL was also associated with reduced lodging in two experiments. A near-isogenic line (culm length 62.9-73.4 cm) in an 'Azumamugi' background, carrying a chromosome segment containing the qCUL allele from Kanto Nakate Gold, was significantly shorter than its recurrent parent (82.9-89.4 cm). The F(2) generation from the next backcross segregated for plant height in a Mendelian monogenic ratio. The qCUL locus was shown to be tightly linked (1.2 cM) with the codominant STS marker ABG608.


Assuntos
Hordeum/genética , Caules de Planta/anatomia & histologia , Locos de Características Quantitativas/genética , Mapeamento Cromossômico , Cruzamentos Genéticos , Hordeum/anatomia & histologia , Japão
7.
Trop Doct ; 37(1): 18-21, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17326880

RESUMO

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 Visual
8.
Public Health ; 121(2): 130-6, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17215012

RESUMO

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 Visual
9.
Curr Top Microbiol Immunol ; 302: 123-43, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16620027

RESUMO

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/genética
10.
Theor Appl Genet ; 112(7): 1392-9, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16525839

RESUMO

Popping expansion volume (PEV) in popcorn (Zea mays L.) is a distinct heritable character and defined as the ratio of the volume after popping to the volume before popping. PEV is quantitatively inherited and 3-4 genes/quantitative trait loci (QTLs) have been implicated. In the present study, we have dissected the quantitative PEV into two component traits, viz., flake volume (FV) and percent unpopped kernels (UPK), and mapped QTLs using SSR markers for all three traits with 194 F3 families derived from a popcorn (A-1-6) x flint corn (V273) cross. Heritability (broad sense) estimates for PEV, FV and UPK based on F3 mean bases were 0.72, 0.54 and 0.68, respectively. The QTL analyses for the three traits based on combined environment data were performed by composite interval mapping using QTL cartographer. Four QTLs were identified for PEV on chromosomes 1, 3, 8 and 10, which together explained 62% of the phenotypic variance (sigma2p). Four QTLs were found on chromosomes 1, 5, 9 and 10 for FV (explaining 44% of sigma2p) and five QTLs for UPK on chromosomes 1, 3, 4, 5 and 9 (explaining 57% of sigma2p). The relative efficiency estimates of marker-based selection in comparison to phenotypic selection for PEV (1.10), FV (1.22) and UPK (1.11) indicated that marker-based selection could be relatively more efficient. The QTL on chromosome 1S for PEV was found to be most significant, where QTLs for hard endosperm starch concentration had been detected earlier.


Assuntos
Mapeamento Cromossômico , Cromossomos de Plantas , Cruzamentos Genéticos , Locos de Características Quantitativas , Zea mays/genética , Alelos , DNA de Plantas , Meio Ambiente , Genes de Plantas , Ligação Genética , Marcadores Genéticos , Variação Genética , Hibridização Genética , Repetições de Microssatélites , Polimorfismo de Fragmento de Restrição , Estações do Ano , Seleção Genética , Moldes Genéticos
11.
J Mol Endocrinol ; 35(2): 211-23, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16216903

RESUMO

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/genética
12.
Theor Appl Genet ; 111(5): 888-97, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16034586

RESUMO

The low nutritive value of maize endosperm protein is genetically corrected in quality protein maize (QPM), which contains the opaque 2 gene along with numerous modifiers for kernel hardness. We report here a two generation marker-based backcross breeding program for incorporation of the opaque 2 gene along with phenotypic selection for kernel modification in the background of an early maturing normal maize inbred line, V25. Using the flanking marker distances from opaque 2 gene in the cross V 25 xCML 176, optimum population size for the BC(2) generation was computed in such a way that at least one double recombinant could be obtained. Whole genome background selection in the BC(2) generation identified three plants with 93 to 96% recurrent parent genome content. The three BC(2)F(2) families derived from marker identified BC(2) individuals were subjected to foreground selection and phenotypic selection for kernel modification. The tryptophan concentration in endosperm protein was significantly enhanced in all the three classes of kernel modification viz., less than 25%, 25--50% and more than 50% opaqueness. BC(2)F(3) lines developed from the hard endosperm kernels were evaluated for desirable agronomic and biochemical traits in replicated trials and the best line was chosen to represent the QPM version of V25, with tryptophan concentration of 0.85% in protein. The integrated breeding strategy reported here can be applied to reduce genetic drag as well as the time involved in a conventional line conversion program, and would prove valuable in rapid development of specialty corn germ plasm.


Assuntos
Zea mays/genética , Zea mays/normas , Cruzamentos Genéticos , Marcadores Genéticos , Genoma de Planta , Endogamia , Fenótipo , Polimorfismo Genético , Recombinação Genética , Sementes/genética , Seleção Genética
13.
Theor Appl Genet ; 110(8): 1384-92, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15841363

RESUMO

We have mapped the quantitative trait loci (QTLs) conferring resistance to sorghum downy mildew (Peronosclerospora sorghi; SDM) and Rajasthan downy mildew (P. heteropogoni; RDM), two species of DM prevalent throughout India. QTL mapping was carried out on a backcross population of 151 individuals derived from a cross between CM139 (susceptible parent) and NAI116 (highly resistant to both SDM and RDM). Heritability estimates were 0.74 for SDM and 0.67 for RDM. Composite interval mapping combined with a linkage map constructed with 80 simple sequence repeat (SSR) markers resulted in the identification of three QTLs (one each on chromosomes 2, 3 and 6) for SDM resistance and two QTLs (one each on chromosomes 3 and 6) for RDM resistance, all of which were contributed by NAI116. The significance of the major QTL on chromosome 6 (bin 6.05) that confers resistance to diverse DMs in tropical Asia, including SDM and RDM in India, was also verified. The results confirmed that some common QTLs contribute to both SDM and RDM resistance, while additional loci might specifically govern resistance to SDM. The QTL information generated in this study provide information that will aid in undertaking an integrated breeding strategy for the transfer of resistance to SDM and RDM in maize lines using marker-assisted selection.


Assuntos
Mapeamento Cromossômico , Imunidade Inata/genética , Oomicetos , Doenças das Plantas/microbiologia , Locos de Características Quantitativas , Zea mays/genética , Cruzamento/métodos , Cruzamentos Genéticos , Índia , Repetições Minissatélites/genética , Zea mays/microbiologia
14.
Org Lett ; 3(12): 1813-5, 2001 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-11405718

RESUMO

[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/farmacologia
15.
J Immunol ; 166(5): 2953-60, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11207244

RESUMO

Polyvalent cancer vaccines targeting the entire antigenic spectrum on tumor cells may represent a superior therapeutic strategy for cancer patients than vaccines solely directed against single Ags. In this study, we show that autologous dendritic cells (DC) transfected with RNA amplified from microdissected tumor cells are capable of stimulating CTL against a broad set of unidentified and critical prostate-specific Ags. Although the polyclonal CTL responses generated with amplified tumor RNA-transfected DC encompassed as a subcomponent a response against prostate-specific Ag (PSA) as well as against telomerase reverse transcriptase, the tumor-specific CTL were consistently more effective than PSA or telomerase reverse transcriptase CTL to lyse tumor targets, suggesting the superiority of the polyclonal response. Although tumor RNA-transfected DC stimulated CTL, which recognized not only tumor but also self-Ags expressed by benign prostate tissue, these cross-reactive CTL were exclusively specific for the PSA, indicating an immunodominant role of PSA in the prostate cancer-specific immune response. Our data suggest that tumor RNA-transfected DC may represent a broadly applicable, potentially clinically effective vaccine strategy for prostate cancer patients, which is not limited by tumor tissue availability for Ag preparation and may minimize the risk of clonal tumor escape.


Assuntos
Citotoxicidade Imunológica/genética , Células Dendríticas/imunologia , Epitopos de Linfócito T/imunologia , Ativação Linfocitária/genética , Neoplasias da Próstata/imunologia , RNA Neoplásico/imunologia , Linfócitos T Citotóxicos/imunologia , Transfecção , Adjuvantes Imunológicos/genética , Adjuvantes Imunológicos/metabolismo , Células Cultivadas , Células Clonais , Reações Cruzadas/genética , Testes Imunológicos de Citotoxicidade , Células Dendríticas/metabolismo , Dissecação , Amplificação de Genes/imunologia , Humanos , Masculino , Antígeno Prostático Específico/imunologia , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , RNA Mensageiro/imunologia , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , Linfócitos T Citotóxicos/metabolismo , Transcrição Gênica/imunologia
16.
Ann Card Anaesth ; 4(1): 33-6, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17851160

RESUMO

A 48 yr. old patient suffering from bicarotid trunk and left subclavian artery stenosis with severe coronary artery disease was managed successfully by angioplasty and stenting of the bicarotid trunk and subclavian artery. This was followed by coronary artery bypass grafting after one month. He was free of angina and cerebrovascular symptoms at one and a half year follow up.

18.
J Org Chem ; 65(23): 7792-9, 2000 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-11073583

RESUMO

Two efficient protocols for the synthesis of tert-butyl (5S,6R,2E, 7E)-5-[(tert-butyldimethylsilyl)oxy]-6-methyl-8-phenyl-2, 7-octadienoate, a major component of the cryptophycins, are reported. The first utilized the Noyori reduction and Frater alkylation of methyl 5-benzyloxy-3-oxopentanoate to set two stereogenic centers, which became the C16 hydroxyl and C1' methyl of the cryptophycins. The second approach started from 3-p-methoxybenzyloxypropanal and a crotyl borane reagent derived from (-)-alpha-pinene to set both stereocenters in a single step and provided the dephenyl analogue, tert-butyl (5S,6R,2E)-5-[(tert-butyldimethylsilyl)oxy]-6-methyl-2, 7-octadienoate, in five steps. This compound was readily converted to the 8-phenyl compound via Heck coupling. The silanyloxy esters were efficiently deprotected and coupled to the C2-C10 amino acid fragment to provide desepoxyarenastatin A and its dephenyl analogue. The terminal olefin of the latter was further elaborated via Heck coupling. Epoxidation provided cryptophycin-24 (arenastatin A).


Assuntos
Antineoplásicos/síntese química , Depsipeptídeos , Peptídeos Cíclicos/síntese química , Relação Estrutura-Atividade
19.
Blood ; 96(10): 3499-504, 2000 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11071647

RESUMO

Dendritic cells (DCs) may arise from multiple lineages and progress through a series of intermediate stages until fully mature, at which time they are capable of optimal antigen presentation and T-cell activation. High cell surface expression of CD83 is presumed to correlate with full maturation of DCs, and a number of agents have been shown to increase CD83 expression on DCs. We hypothesized that interleukin 12 (IL-12) expression would be a more accurate marker of functionally mature DCs capable of activating antigen-specific T cells. We used combinations of signaling through CD40, using CD40 ligand trimer (CD40L), and interferon gamma to demonstrate that CD83 expression is necessary but not sufficient for optimal production of IL-12 by DCs. Phenotypically mature DCs could be induced to produce high levels of IL-12 p70 only when provided 2 simultaneous stimulatory signals. By intracellular cytokine detection, we determined that only a subset of cells that express high levels of CD80 and CD83 generate large amounts of IL-12. DCs matured with both signals are superior to DCs stimulated with the individual agents in activating antigen-specific T cell in vitro. These findings have important implications regarding the identification, characterization, and clinical application of functionally mature DCs.


Assuntos
Ligante de CD40/farmacologia , Células Dendríticas/efeitos dos fármacos , Interferon gama/farmacologia , Interleucina-12/metabolismo , Adjuvantes Imunológicos/metabolismo , Apresentação de Antígeno/efeitos dos fármacos , Antígenos CD , Antígeno B7-1/metabolismo , Antígeno B7-1/fisiologia , Biomarcadores , Técnicas de Cultura de Células , Diferenciação Celular , Testes Imunológicos de Citotoxicidade , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Citometria de Fluxo , Técnica Direta de Fluorescência para Anticorpo , Humanos , Imunoglobulinas/metabolismo , Imunoglobulinas/fisiologia , Imunofenotipagem , Interleucina-12/imunologia , Lipopolissacarídeos/farmacologia , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/fisiologia , Monócitos/citologia , Subunidades Proteicas , Antígeno CD83
20.
Nat Med ; 6(9): 1011-7, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10973321

RESUMO

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 terapêutico
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