RESUMO
BACKGROUND: Whether supplemental intraoperative oxygen reduces surgical site infections remains unclear. Recent recommendations from the World Health Organization and Center for Disease Control to routinely use high inspired oxygen concentrations to reduce infection risk have been widely criticized. We therefore performed a meta-analysis to evaluate the influence of inspired oxygen on infection risk, including a recent large trial. METHODS: A systematic literature search was performed. Primary analysis included all eligible trials. Sensitivity analyses distinguished studies of colorectal and non-colorectal surgeries, and excluded studies with high risk of bias. Another post-hoc sensitivity analysis excluded studies from one author that appear questionable. RESULTS: The primary analysis included 26 trials (N=14,710). The RR [95%CI] for wound infection was 0.81 [0.70, 0.94] in the high vs. low inspired oxygen groups. The effect remained significant in colorectal patients (N=10,469), 0.79 [0.66, 0.96], but not in other patients (N=4,241), 0.86 [0.69, 1.09]. When restricting the analysis to studies with low risk of bias, either by strict inclusion criteria (N=5,047) or by researchers' judgment (N=12,547), no significant benefit remained: 0.84 [0.67, 1.06] and 0.89 [0.76, 1.05], respectively. CONCLUSIONS: When considering all available data, intraoperative hyperoxia reduced wound infection incidence. However, no significant benefit remained when analysis was restricted to objective- or investigator-identified low-bias studies, although those analyses were not as well-powered. Meta-analysis of the most reliable studies does not suggest that supplemental oxygen substantively reduces wound infection risk, but more research is needed to fully answer this question.
Assuntos
Cuidados Intraoperatórios/métodos , Oxigenoterapia/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Viés , HumanosRESUMO
Cullin 4B (CUL4B), a member of the cullin protein family, is a scaffold protein of the CUL4B-RING-E3 ligase complex that ubiquitinates intracellular proteins.CUL4B's targets include cell cycle-regulated proteins and DNA replication-related molecules. In this study, we generated myeloid-specific Cul4b-deficient mice (Cul4b(f/y);LysM-Cre(KI/KI)) to investigate the influence of Cul4b deficiency on innate immunity, especially on the function of macrophages. Our results show that an intraperitoneal injection of lipopolysaccharide (LPS) led to a significant decrease in body weights and increased leukocyte infiltrates with increased chemokines in the peritoneal cavity of Cul4b(f/y);LysM-Cre(KI/KI) mice. However, the proinflammatory cytokines, IL-6 and TNF-α did not increase in LPS-injected Cul4b(f/y);LysM-Cre(KI/KI) mice. Furthermore, bone marrow-derived macrophages from Cul4b(f/y);LysM-Cre(KI/KI) mice secreted higher levels of chemokines but lower levels of TNF-α and IL-6 upon LPS stimulation. Of note, increased proliferation of Cul4b-deficient macrophages was also observed. These results show that myeloid-specific Cul4b deficiency worsens LPS-induced peritonitis. In addition, Cul4b deficiency leads to enhanced DNA replication and proliferation, increased production of chemokines but a decreased production of proinflammatory cytokines of macrophages. Our data highlight a new role of cullin family, CUL4B, in the immune system.
Assuntos
Proteínas Culina/imunologia , Imunidade Inata/imunologia , Macrófagos/imunologia , Peritonite/imunologia , Animais , Peso Corporal/imunologia , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Ciclo Celular/genética , Ciclo Celular/imunologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Quimiocinas/imunologia , Quimiocinas/metabolismo , Proteínas Culina/genética , Proteínas Culina/metabolismo , Expressão Gênica/imunologia , Imunidade Inata/genética , Imunoensaio , Interleucina-6/genética , Interleucina-6/imunologia , Interleucina-6/metabolismo , Leucócitos/imunologia , Leucócitos/metabolismo , Lipopolissacarídeos , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Peritonite/induzido quimicamente , Peritonite/genética , Fagocitose/genética , Fagocitose/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
This corrects the article DOI: 10.1038/onc.2014.445.
RESUMO
The SET protein is a potent inhibitor of protein phosphatase 2A (PP2A). Here, we report the oncogenic role of SET in hepatocarcinogenesis, clinical aggressiveness and anti-hepatocellular carcinoma (HCC) therapeutics. By analyzing samples obtained from 147 HCC patients, we found that SET overexpression was detected specifically in 30.6% HCC tumor samples, and was significantly associated with worse clinical features and high p-Akt expression in HCC tumors. Co-expression of SET and Akt predicted shorter post-operative recurrence-free survival in this cohort (P=0.045). Furthermore, SET was significantly associated with cell growth and hepatosphere formation. To elucidate the anti-HCC potential of targeting SET, we generated a novel SET antagonist, EMQA (N(4)-(3-ethynylphenyl)-6,7-dimethoxy-N(2)-(4-phenoxyphenyl) quinazoline-2,4-diamine). EMQA enhanced PP2A activity via disrupting SET-PP2Ac (catalytic domain of PP2A) binding in HCC cells, which restored PP2A-mediated p-Akt downregulation and promoted HCC cell death. In HCC cells or recombinant proteins expressing the N- and C- truncated forms of SET, only the C-terminal SET was required for EMQA targeting. Furthermore, combining sorafenib and EMQA showed good synergism in inhibiting HCC survival. Our findings suggested the oncogenic role of SET and the adverse prognostic value of SET overexpression in HCC. This alteration defines a subgroup of HCC patients who could benefit from SET antagonists, such as EMQA.
Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Chaperonas de Histonas/genética , Neoplasias Hepáticas/tratamento farmacológico , Prognóstico , Quinazolinas/administração & dosagem , Fatores de Transcrição/genética , Animais , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas de Ligação a DNA , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Chaperonas de Histonas/antagonistas & inibidores , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Niacinamida/administração & dosagem , Niacinamida/análogos & derivados , Compostos de Fenilureia/administração & dosagem , Quinazolinas/síntese química , Sorafenibe , Fatores de Transcrição/antagonistas & inibidores , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Epithelial-to-mesenchymal transition (EMT) is well known to involve in tumor invasion and metastasis. Src homology region 2 domain-containing phosphatase 1 (SHP-1) functions as a potent tumor suppressor and also acts as a negative regulator of p-STAT3(Tyr705) oncogenic signaling. However, little is known about the molecular mechanism(s) through which SHP-1 regulates EMT during hepatocellular carcinoma (HCC) progression. Here we first reported that endogenous SHP-1 protein levels were significantly downregulated in cells with mesenchymal characteristics and negatively correlated with p-STAT3(Tyr705) and vimentin but positively correlated with E-cadherin. SHP-1 overexpression abolished transforming growth factor-ß1 (TGF-ß1)-induced p-STAT3(Tyr705) and EMT, as well inhibited migration and invasion but further rescued by signal transducer and activator of transcription factor 3 (STAT3) overexpression. Depletion of SHP-1 could induce a more increase in TGF-ß1-induced p-STAT3(Tyr-705) and EMT characteristics, further supporting the mechanism that suppression of TGF-ß1-induced EMT is dependent on SHP-1-mediated STAT3 inactivation. Constitutively overexpressed SHP-1 tyrosine phosphatase activity by D61A-mutated SHP-1 markedly reduced TGF-ß1-induced p-STAT3(Tyr705) and EMT features but was not altered by C453S catalytic-dead mutant SHP-1. Consequently, SHP-1 acted as a powerful suppressor in preventing EMT by exerting its tyrosine phosphatase activity that directly downregulated p-STAT3(Tyr705). Most notably, we discovered a novel SHP-1 agonist SC-43 better than sorafenib to exert more potent anti-EMT effects in vitro as well as anti-metastatic growth in vivo. In conclusion, SHP-1 is a potent suppressor of HCC EMT and metastasis, thus highlighting that SC-43-SHP-1 axis may serve as a potential therapeutic target that antagonized p-STAT3(Tyr705) and thereby prevented HCC EMT and metastasis.
Assuntos
Carcinoma Hepatocelular/enzimologia , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas/enzimologia , Neoplasias Pulmonares/enzimologia , Proteína Tirosina Fosfatase não Receptora Tipo 6/fisiologia , Animais , Carcinoma Hepatocelular/secundário , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Pulmonares/secundário , Camundongos Nus , Transplante de Neoplasias , Fator de Transcrição STAT3/metabolismoRESUMO
Fat and fat-free tissues were determined in hemodialysis patients using either anthropometric measurements or indirectly from total body water (TBW) determined from urea kinetics. A very close correlation between the two methods in determining either fat or fat-free tissue (r greater than 0.8, n = 43) was shown. Twenty-two patients were followed for 2 yr. We found that fat increased while fat-free tissue decreased over that period of time. The latter appears to reflect methodological problems since both fat-free determinations depend upon TBW rather than somatic proteins. This was further confirmed by finding a proportional decrease in TBW with time, while creatinine appearance rate remained unaffected. Adherence to prescribed diet was monitored through diet records and periodic determination of urea N appearance rate during interdialysis periods. Our present studies determined body composition of hemodialysis patients and examined the relative validity of the commonly used methods. We demonstrate that no malnutrition occurs with time in patients adhering to their prescribed diet.
Assuntos
Fenômenos Fisiológicos da Nutrição , Diálise Renal , Tecido Adiposo/metabolismo , Antropometria , Nitrogênio da Ureia Sanguínea , Composição Corporal , Água Corporal/análise , Peso Corporal , Creatinina/análise , Estudos Transversais , Feminino , Metabolismo dos Lipídeos , Estudos Longitudinais , Masculino , Músculos/metabolismo , Distúrbios Nutricionais/etiologia , Proteínas/metabolismo , Diálise Renal/efeitos adversosRESUMO
BACKGROUND: By the use of conditional probabilities of survival, we studied the yearly survival rates for individual tumor survivors. METHODS: Conditional survival rate was estimated in 114 consecutive patients with anaplastic astrocytoma or glioblastoma multiforme. Conditional probabilities of surviving some years given survival to a specific period of time after craniotomy and 95% confidence intervals were calculated in the individual tumor survivors. RESULTS: The estimated median survival was 30 months for 45 patients with anaplastic astrocytoma and 12 months for 69 patients with glioblastoma multiforme. The conditional probabilities of surviving next one year given survival to 1 year, 2 years, 3 years, 4 years, or 5 years after craniotomy for anaplastic astrocytoma were 86.2%, 75.0%, 85.9%, 77.8%, or 85.7%, respectively; for glioblastoma multiforme 64.8%, 58.7%, 85.7%, 80.0%, or 75.0%, respectively. The conditional probability of surviving to 5 years given survival to 2 years after craniotomy for anaplastic astrocytoma, i.e., surviving an additional 3 years, was 50.1%, which was better than observed 5-year survival rate (28.6%); for glioblastoma multiforme it was 40.2%, which also was better than observed 5-year survival rate (12.4%). CONCLUSIONS: The conditional probability of survival was a good method to clinically predict yearly survival rate for individual tumor survivors. In addition, the method can estimate the probabilities of surviving next some years given survival to a specific period of time after craniotomy. It also showed a more encouraging result than observed survival rate in patients with supratentorial malignant astrocytomas.
Assuntos
Astrocitoma/mortalidade , Glioblastoma/mortalidade , Neoplasias Supratentoriais/mortalidade , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Retrospectivos , Análise de Sobrevida , Taxa de Sobrevida , Taiwan/epidemiologiaRESUMO
Glycocalyx is suggested to play an important role in the pathogenesis of biomaterial-centered infection. Using an accurate and sensitive method to quantify glycocalyx and bacterial adherence, we have demonstrated that the producer of the most glycocalyx also exhibited the highest adherence index, whereas low producers exhibited the least (p less than 0.01). Additionally, at various concentrations the high producer had the greater tendency to adhere and grow on stainless steel wires and tubes (p less than 0.001). The adherence index, referred as the ratio of tritiated thymidine uptake on wires to colony forming units (CFU), was also the highest in high producers. The adherence index increased as the glycocalyx index increased. It was suggested that glycocalyx production enhanced the adherence of Staphylococcus epidermidis to biomaterials and caused persistent and intractable infections. In short, the glycocalyx index and the adherence index can be reliable indices of biomaterial-centered infection.
Assuntos
Aderência Bacteriana , Materiais Biocompatíveis/efeitos adversos , Glicoproteínas/biossíntese , Polissacarídeos/biossíntese , Staphylococcus epidermidis/fisiologia , Timidina/metabolismoRESUMO
In this paper, an efficient and systematic formulation of the force distribution equations for general tree-structured robotic mechanisms is presented. The applicable platforms include not only systems with star topologies, such as walking machines that have multiple legs with a single body but also general tree-structured mechanisms, such as variably configured wheeled vehicles having multiple modules. The force balance equations that govern the relationship between the contact forces and the resultant inertial forces/moments of the vehicle will be derived through a recursive and computationally efficient algorithm. Also, the joint torque constraints that specify the joint actuator limits, and contact friction constraints that may be used to avoid slippage and maintain contact, are efficiently incorporated in the formulation. Based on this formulation, several standard optimization techniques, such as linear programming or quadratic programming, can be applied to obtain the solution. An algorithm summarizing the results developed, and suitable for computer implementation, is included. The algorithm has been applied to an n-module actively articulated wheeled vehicle, and the computational cost evaluated. The efficiency of the algorithm is demonstrated with results showing real-time execution on a Pentium PC.
RESUMO
The improved diagnostic capacity of computed tomography (CT) may have resulted in improved detection of intracranial tumors. We were interested to know whether the frequency of intracranial tumors has changed after the introduction of CT in Taiwan. The relative incidences of intracranial tumors in Taiwan were analyzed from the hospital based data. Our data showed that meningiomas were the most encountered intracranial tumors. Neuroepithelial tumors in our series (in the post-CT era) (23.9%) were apparently lower than those found in the pre-CT era (36.0%). However, the relative incidences of meningiomas and pituitary adenomas after the use of CT (24.2%, 21.1%, respectively) were much higher than those found before the use of CT (14.5%, 7.7%, respectively). Our data suggest that the increased incidence for benign tumors and the decreased incidence for malignant tumors may have resulted from the improved diagnostic capacity of CT, which reduces the number of undetected tumor cases.
Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Neoplasias Encefálicas/epidemiologia , Humanos , Incidência , Pessoa de Meia-Idade , Taiwan/epidemiologiaRESUMO
Protein phosphatase 2A (PP2A) is a tumor suppressor, which is functionally defective in various cancers. Previously, we found that PP2A activity determined the anticancer effect of bortezomib and erlotinib in hepatocellular carcinoma (HCC) cells. Here, we tested a novel erlotinib derivative, TD52, in four HCC cell lines, PLC5, Huh-7, Hep3B and Sk-Hep1. Using MTT and flow cytometry, we showed that TD52 had more potent apoptotic effects than erlotinib in HCC cells. TD52-induced apoptosis was associated with dose- and time- dependent reactivation of PP2A and downregulation of cancerous inhibitor of protein phosphatase 2A (CIP2A) and p-Akt. Inhibition of PP2A or ectopic expression of CIP2A or Akt in PLC5 cells abolished the effects of TD52. Furthermore, we demonstrated that TD52 affected the binding of Elk-1 to the proximal promoter of the CIP2A gene, thus downregulating transcription of CIP2A. Importantly, TD52-induced tumor inhibition was associated with reactivation of PP2A and downregulation of CIP2A and p-Akt in vivo. In conclusion, we found that enhancement of PP2A activity by inhibition of CIP2A determines the apoptotic effect induced by TD52. Our findings disclose the therapeutic mechanism of this novel targeted agent, and suggest the therapeutic potential and feasibility of developing PP2A enhancers as a novel anticancer strategy.
Assuntos
Antineoplásicos/farmacologia , Autoantígenos/metabolismo , Carcinoma Hepatocelular/enzimologia , Neoplasias Hepáticas/enzimologia , Proteínas de Membrana/metabolismo , Proteína Fosfatase 2/metabolismo , Quinazolinas/farmacologia , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Autoantígenos/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/fisiopatologia , Linhagem Celular Tumoral , Cloridrato de Erlotinib , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/fisiopatologia , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Nus , Proteína Fosfatase 2/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quinazolinas/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Although routine bacterial culture is the traditional reference standard method for the detection of Salmonella infection in children with diarrhoea, it is a time-consuming procedure that usually only gives results after 3-4 days. Some molecular detection methods can improve the turn-around time to within 24 h, but these methods are not applied directly from stool or rectal swab specimens as routine diagnostic methods for the detection of gastrointestinal pathogens. In this study, we tested the feasibility of a bacterial enrichment culture-based real-time PCR assay method for detecting and screening for diarrhoea in children caused by Salmonella. Our results showed that the minimum real-time PCR assay time required to detect enriched bacterial culture from a swab was 3 h. In all children with suspected Salmonella diarrhoea, the enrichment culture-based real-time PCR achieved 85.4% sensitivity and 98.1% specificity, as compared with the 53.7% sensitivity and 100% specificity of detection with the routine bacterial culture method. We suggest that rectal swab sampling followed by enrichment culture-based real-time PCR is suitable as a rapid method for detecting and screening for Salmonella in paediatric patients.
Assuntos
Enterocolite/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reto/microbiologia , Intoxicação Alimentar por Salmonella/microbiologia , Salmonella/genética , Salmonella/isolamento & purificação , Técnicas de Cultura de Células , Criança , Estudos de Coortes , Diarreia/microbiologia , Humanos , Intoxicação Alimentar por Salmonella/diagnóstico , Sensibilidade e EspecificidadeRESUMO
The taxonomic status of a light-orange-coloured bacterial isolate from an oil-contaminated soil sample was characterized by using a polyphasic taxonomic approach. Comparative analysis of 16S rRNA gene sequences demonstrated that the isolate belonged phylogenetically to the genus Azospirillum, with Azospirillum canadense, Azospirillum brasilense and Azospirillum doebereinerae as its closest phylogenetic relatives (97.3, 97.0 and 97.0 % similarity, respectively). DNA-DNA pairing studies showed that the unidentified organism displayed 25.0, 17.0 and 19.0 % relatedness to the type strains of A. brasilense, A. canadense and A. doebereinerae, respectively. The generic assignment was confirmed by chemotaxonomic data, which revealed a fatty acid profile that was characteristic of the genus Azospirillum, consisting of straight-chain saturated and unsaturated fatty acids with C18 : 1 omega 7c as the major fatty acid, and ubiquinone with ten isoprene units (Q-10) as the predominant respiratory quinone. On the basis of both the phenotypic and molecular genetic evidence, it is proposed that the unknown isolate be classified as a representative of a novel species of the genus Azospirillum, for which the name Azospirillum rugosum sp. nov. is proposed. The type strain is IMMIB AFH-6T (=CCUG 53966T=DSM 19657T).
Assuntos
Azospirillum/classificação , Azospirillum/isolamento & purificação , Azospirillum/genética , Azospirillum/metabolismo , DNA Bacteriano/genética , Ácidos Graxos/metabolismo , Óleos Combustíveis , Genes Bacterianos , Dados de Sequência Molecular , Fenótipo , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Microbiologia do Solo , Poluentes do Solo/metabolismo , Especificidade da Espécie , Terminologia como Assunto , Ubiquinona/metabolismoRESUMO
Alkaline deoxyribonuclease activity was detected in culture of Mycoplasma pneumoniae. This enzyme required MgCl2 to stimulate its activity and preferred double-stranded to single-stranded DNA as substrate. By using polyacrylamide gel electrophoresis or isoelectric electrofocusing, two distinctive deoxyribonuclease activities were demonstrated both in cultured broth and cell homogenate.
Assuntos
Desoxirribonucleases/análise , Mycoplasma pneumoniae/enzimologia , Desoxirribonucleases/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Focalização IsoelétricaRESUMO
Epitopes recognized by factor VIII (FVIII) inhibitors of Chinese origin were analysed by immunoblotting with full-length recombinant FVIII (rFVIII), thrombin-activated FVIII (FVIIIa) and 16 FVIII fusion proteins synthesized by bacteria. Twenty-eight patients, 12 with haemophilia A and 16 with autoimmune diseases, were recruited. Antibodies from 22 patients showed reactivity with rFVIII, 20 with FVIIIa, and one reacted only with FVIII fusion proteins. Of these 22 cases, most were reactive with A2-a2 and A3-C1-C2 of FVIII(a). Of the nine cases that depicted binding to the fusion proteins, three were reactive with the A domains, three with only the B domain, and the other three with both the A and B (or C) domains. An epitope for a neutralizing antibody of a haemophilia A patient, designated TWN-112, was localized to residues 323-390, specified by FVIII fusion proteins. The same epitope also appeared on an FVIII-expression phage library screening. Immunoabsorption of antibodies from TWN-112 with the epitope reduced the neutralizing activity of the inhibitor by 33%. The incidence of a1 of FVIII is higher, and that of a3 is lower, than previously reported. Two novel epitopes, reported for the first time in this paper, were localized on the 8B2 (amino acid residues 1022-1204) and 8A2(V) (residues 673-740) fusion proteins. These two epitopes were able to reduce inhibitory antibody activity by 24% and 25% respectively. Changes of FVIII fragment specificity were also observed in one of six patients for whom multiple samples, collected at different times, were available. Our initial finding showed that the FVIII inhibitors in these Chinese patients shared epitopes with those of patients from very different genetic backgrounds, suggesting a common mechanism for the development of FVIII inhibitors.
Assuntos
Autoanticorpos/sangue , Fator VIII/imunologia , Hemofilia A/imunologia , Isoanticorpos/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Mapeamento de Epitopos , Humanos , Immunoblotting/métodos , Pessoa de Meia-Idade , Sensibilidade e Especificidade , TaiwanRESUMO
This paper presents an assay of clindamycin phosphate injection in human plasma or serum. A 0.5-ml volume of plasma was used with the internal standard, propranolol. The sample was loaded onto a silica extraction column. The column was washed with deionized water and then eluted with methanol. The eluates were evaporated under nitrogen gas. The residue was reconstituted with the mobile phase and injected onto the high-performance liquid chromatographic system: a 5-micron, 25 cm X 4.6 mm I.D. ODS2 column was used with acetonitrile, tetrahydrofuran and 0.05 M phosphate buffer as the mobile phase and with ultraviolet detection at 204 nm. A limit of quantitation of 0.05 microgram/ml was found, with a coefficient of variation of 11.6% (n = 6). The linear range is between 0.05 and 20.00 micrograms/ml and gives a coefficient of determination (r2) or 0.9992. The method has been successfully applied to the bioavailability study of two commercial preparations of clindamycin phosphate injection (300 mg each) in twelve healthy adult male volunteers.
Assuntos
Antibacterianos/sangue , Cromatografia Líquida de Alta Pressão/métodos , Clindamicina/análogos & derivados , Clindamicina/sangue , Adulto , Humanos , Masculino , Padrões de Referência , Valores de Referência , Espectrofotometria UltravioletaRESUMO
A new perfluorocarbon, PTBD (perfluoro-2,2,2',2'-tetramethyl-4,4'-bis(1,3-dioxolane)), is described for use in 19F MR imaging and spectroscopy. Two-thirds of the molecular fluorine in PTBD resonates at a single frequency and can be imaged without the use of frequency-selective spin-echo (SE) MRI pulse sequences to suppress chemical shift artifacts. The absence of strong homonuclear spin-spin coupling to the imagable -CF3 groups in PTBD minimizes signal attenuation in 19F SE MRI due to J-modulation effects. For equimolar concentrations of perfluorocarbon, PTBD gives an approximately 17% increase in sensitivity, relative to literature results for perfluorinated amines, at short values of TE (approximately 10 ms) in 19F SE MRI. These attributes allow 19F MRI of PTBD to be performed on standard clinical imaging instrumentation (without special hardware and/or software modification) and an in vivo example in a mouse is shown. This investigation involved characterizing the MR T1 and T2 relaxation times of PTBD as well as the MR spin-lattice relaxation rate, R1 (1/T1), of PTBD as a function of dissolved oxygen concentration. The T1 and T2 relaxation times and R1 relaxation rates of perfluorooctyl bromide (PFOB) were also obtained, under similar experimental conditions, to compare and contrast PTBD with a representative perfluorocarbon that has been widely employed for 19F MRI/MRS applications.
Assuntos
Dioxolanos , Fluorocarbonos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Animais , Flúor , Espectroscopia de Ressonância Magnética/métodos , Camundongos , Camundongos Endogâmicos C3H , Modelos Estruturais , Distribuição TecidualRESUMO
OBJECTIVE: p53 gene alteration has been extensively studied in epithelial ovarian cancer. However, its occurrence in clear cell carcinoma, an infrequent histologic subtype of epithelial ovarian cancer, is rarely reported. The aim of this study is to determine the status of p53 gene alteration in this distinct type of ovarian carcinoma. METHODS: Paraffin blocks of tumors from 38 patients with primary or recurrent ovarian clear cell carcinoma were studied for p53 alteration. All these tumors were subjected to immunohistochemical and molecular analysis. Two monoclonal antibodies (DO-7 and PAb 1801) were used for immunohistochemical staining. Genomic DNAs extracted from paraffin blocks of the 38 tumors were subscribed for a nested polymerase chain reaction/single-strand conformation polymorphism (PCR/SSCP) analysis. Tumors showing band shift on SSCP were further prepared for DNA sequencing to determine the site of mutation. RESULTS: Overexpression of p53 was observed in only one stage III clear cell carcinoma. However, focal positive p53 staining was noted in another five tumors. Of the six tumors showing positive immunohistochemistry, p53 alterations were noted in four tumors. Three tumors revealed a missense point mutation: two were in exon 7 (TCT(227) --> TTT and GGC(245) --> AGC) and one was in exon 5 (CGC(156) --> CAC). Another tumor revealed a 12-bp deletion in two possible ways: it might involve the last four codons at the 3' end of exon 4 (nucleotides 12,288-12,299) or it might cross over the splice junction between exon 4 and intron 4 (nucleotides 12,290-12,301). The former would result in a predicted protein product of 389 amino acids whereas the latter would cause a frameshift in the gene sequence and would result in a truncated protein. CONCLUSION: Mutations in p53 appear to be much less frequent in clear cell carcinoma than in other histologic types of epithelial ovarian cancer. We suggest that p53 alterations may not play an important role in the development of clear cell carcinoma.