RESUMO
Intermittent exposure to hypoxia can lead to improved endurance performance. Currently, it is unclear whether peripheral adaptions play a role in improving oxygen delivery and utilization following both training and detraining. This study aimed to characterize skeletal muscle blood flow (mBF), oxygen consumption (mVÌO2), and perfusion adaptations to i) 4-weeks handgrip training in hypoxic and normoxic conditions, and ii) following 4-weeks detraining. Using a randomised crossover design, 9 males completed 30-min handgrip training four times a week in hypoxic (14% FiO2 ~ 3250m altitude) and normoxic conditions. mBF, mVÌO2 and perfusion were assessed pre, post 4-weeks training, and following 4-weeks detraining. Hierarchical linear modelling found that mVÌO2 increased at a significantly faster rate (58%) with hypoxic training (0.09 mlO2·min-1 · 100g-1 per week); perfusion increased at a significantly (69%) faster rate with hypoxic training (3.72 µM per week). mBF did not significantly change for the normoxic condition, but there was a significant increase of 0.38 ml· min-1 · 100ml-1 per week (95% CI: 0.35, 0.40) for the hypoxic condition. During 4-weeks detraining, mVÌO2 and perfusion significantly declined at similar rates for both conditions, whereas mBF decreased significantly faster following hypoxic training. Four weeks hypoxic training increases the delivery and utilisation of oxygen in the periphery.
Assuntos
Antebraço/irrigação sanguínea , Hipóxia , Microcirculação , Músculo Esquelético/irrigação sanguínea , Consumo de Oxigênio , Condicionamento Físico Humano/métodos , Adaptação Fisiológica , Estudos Cross-Over , Antebraço/fisiologia , Força da Mão , Hemodinâmica , Humanos , Modelos Lineares , Masculino , Músculo Esquelético/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Adulto JovemRESUMO
A diffuse flux of astrophysical neutrinos above 100 TeV has been observed at the IceCube Neutrino Observatory. Here we extend this analysis to probe the astrophysical flux down to 35 TeV and analyze its flavor composition by classifying events as showers or tracks. Taking advantage of lower atmospheric backgrounds for showerlike events, we obtain a shower-biased sample containing 129 showers and 8 tracks collected in three years from 2010 to 2013. We demonstrate consistency with the (fe:fµ:fτ)â≈(1:1:1)â flavor ratio at Earth commonly expected from the averaged oscillations of neutrinos produced by pion decay in distant astrophysical sources. Limits are placed on nonstandard flavor compositions that cannot be produced by averaged neutrino oscillations but could arise in exotic physics scenarios. A maximally tracklike composition of (0:1:0)â is excluded at 3.3σ, and a purely showerlike composition of (1:0:0)â is excluded at 2.3σ.
RESUMO
A search for high-energy neutrinos interacting within the IceCube detector between 2010 and 2012 provided the first evidence for a high-energy neutrino flux of extraterrestrial origin. Results from an analysis using the same methods with a third year (2012-2013) of data from the complete IceCube detector are consistent with the previously reported astrophysical flux in the 100 TeV-PeV range at the level of 10(-8) GeV cm-2 s-1 sr-1 per flavor and reject a purely atmospheric explanation for the combined three-year data at 5.7σ. The data are consistent with expectations for equal fluxes of all three neutrino flavors and with isotropic arrival directions, suggesting either numerous or spatially extended sources. The three-year data set, with a live time of 988 days, contains a total of 37 neutrino candidate events with deposited energies ranging from 30 to 2000 TeV. The 2000-TeV event is the highest-energy neutrino interaction ever observed.
RESUMO
Adjuvant radiotherapy is an essential component of the treatment of breast cancer. After conservative surgery for an infiltrating carcinoma, radiotherapy must be systematically performed, regardless of the characteristics of the disease, because it decreases the rate of local recurrence and by this way, specific mortality. A boost dose over the tumour bed is required if the patient is younger than 50 years-old. Partial breast irradiation could be routinely proposed as an alternative to whole breast irradiation, but only in selected and informed patients. For ductal carcinoma in situ, adjuvant radiotherapy must be also systematically performed after lumpectomy. After mastectomy, chest wall irradiation is required for pT3-T4 tumours and if there is an axillary nodal involvement, whatever the number of involved lymph nodes. After neoadjuvant chemotherapy and mastectomy, in case of pN0 disease, chest wall irradiation is recommended if there is a clinically or radiologically T3-T4 or node positive disease before chemotherapy. Axillary irradiation is recommended only if there is no axillary surgical dissection and a positive sentinel lymph node. Supra- and infraclavicular irradiation is advised in case of positive axillary nodes. Internal mammary irradiation must be discussed case by case, according to the benefit/risk ratio (cardiac toxicity). Hypofractionation regimens (42.5Gy in 16 fractions, or 41,6Gy en 13 or 40Gy en 15) are equivalent to conventional irradiation and must prescribe after tumorectomy in selected patients. Delineation of the breast, the chest wall and the nodal areas are based on clinical and radiological evaluations. 3D-conformal irradiation is the recommended technique, intensity-modulated radiotherapy must be proposed only in specific clinical situations. Respiratory gating could be useful to decrease the cardiac dose. Concomitant administration of chemotherapy in unadvised, but hormonal treatment could be start with or after radiotherapy.
Assuntos
Neoplasias da Mama/radioterapia , Carcinoma Intraductal não Infiltrante/radioterapia , Fatores Etários , Neoplasias da Mama/cirurgia , Carcinoma Intraductal não Infiltrante/cirurgia , Cardiotoxicidade , Tratamento Conservador/métodos , Feminino , França , Humanos , Irradiação Linfática , Metástase Linfática , Mastectomia Segmentar , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/prevenção & controle , Cuidados Pós-Operatórios , Radioterapia (Especialidade) , Radioterapia Adjuvante/métodos , Radioterapia Conformacional/métodos , Biópsia de Linfonodo SentinelaRESUMO
IceCube has become the first neutrino telescope with a sensitivity below the TeV neutrino flux predicted from gamma-ray bursts if gamma-ray bursts are responsible for the observed cosmic-ray flux above 10(18) eV. Two separate analyses using the half-complete IceCube detector, one a dedicated search for neutrinos from pγ interactions in the prompt phase of the gamma-ray burst fireball and the other a generic search for any neutrino emission from these sources over a wide range of energies and emission times, produced no evidence for neutrino emission, excluding prevailing models at 90% confidence.
RESUMO
No study on side effects had showed that conformal radiation therapy for prostate cancer is more harmful in patients older than 70 years to patients younger. The aim of this study was to evaluate acute and late toxicities of conformal radiotherapy, with high dose for localized prostate cancer in patients older than 70 years and compared to patients younger than 70 years. Between 1996 and 2009, 104 patients were treated with radiation therapy and hormonal therapy for localized cancer prostate. Median follow-up was 105 months (9-300). Acute (occurred at ≤ three months) and late side effects of 55 patients older than 70 years (median age: 75 [71-92]) were graded according to the CTCAE 3.0 criteria and compared to the younger population. Median dose to the prostate was 75.6 Gy (67-80) in both groups. There were no significant differences in acute and late side effects between age groups. For patients above 70 years, the incidence of grade II or higher acute and late side effects were respectively 27 and 22% for urologic symptoms and 13 and 16% for rectal symptoms. The frequency of grade III late symptoms was low and ranged between 0 and 6% for the evaluated symptoms, irrespective of age group. Older patients had a better biochemical recurrence-free survival than younger patients (86 versus 77% at four years, P=ns). High dose 3D conformal radiotherapy for localized prostate cancer was well tolerated in patients older than 70 years. Age is not a limiting factor for conformal radiation therapy and hormonotherapy for older patients.
Assuntos
Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/efeitos adversos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antagonistas de Androgênios/uso terapêutico , Terapia Combinada , Contraindicações , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/tratamento farmacológico , Radioterapia Conformacional/métodos , Estudos Retrospectivos , Fatores de TempoRESUMO
Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.
RESUMO
Ductal carcinoma in situ is defined as breast cancer confined to the ducts of the breast without evidence of penetration of the basement membrane. Local treatment quality represents one of the most prognostic factors as half of recurrences are invasive diseases. The main goal of adjuvant radiotherapy after conservative surgery is to decrease local recurrences and to permit breast conservation with low treatment-induced sequelae. Several randomized trials have established the impact of 50 Gy to the whole breast in terms of local control. Nevertheless, no randomized trial is still available concerning the role of the boost in this disease. In this review, we present updated results of the literature and we detail the French multicentric randomized trial evaluating the impact of a 16 Gy boost after 50 Gy delivered to the whole breast in 25 fractions and 33 days. This protocol will start inclusions in October 2008.
Assuntos
Neoplasias da Mama/radioterapia , Carcinoma Intraductal não Infiltrante/radioterapia , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Feminino , Humanos , Estudos Multicêntricos como Assunto , Necrose , Invasividade Neoplásica , Recidiva Local de Neoplasia/epidemiologia , Prognóstico , Dosagem Radioterapêutica , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
We have examined the ability of extracellular ATP to elicit intracellular Ca2+ mobilization in a broad range of human leukocytes at particular stages of hematopoietic differentiation. The average cytosolic [Ca2+] in various leukocyte populations was measured in Fura 2-loaded cell suspensions while the cytosolic [Ca2+] in individual, Indo 1-loaded leukocytes was assayed by flow cytometric methods. Utilizing normal blood- and marrow-derived cells, human leukemic cell lines, and mononuclear cell fractions derived from the blood of patients with various leukemias, we have found that ATP-induced Ca2+ mobilization appears restricted to leukocytes of neutrophil/monocyte ontogeny. Significant ATP-induced increases in cytosolic [Ca2+] were observed in neutrophils, monocytes, and myeloid progenitor cells as immature as myeloblasts, but not in lymphocytes. Extensive characterization of the ATP-induced changes in [Ca2+] observed in the HL-60 promyelocytic cell line have indicated these Ca2+-mobilizing effects of ATP can be correlated with an activation of inositol phospholipid breakdown via the occupation of P2-purinergic receptors Significantly, of the various agonists (FMLP, platelet-activating factor, LTB4, and ATP) which elicit equivalent and maximal Ca2+ mobilization in mature neutrophils and monocytes, ATP was the most efficacious stimulant of Ca2+ mobilization in immature neutrophil/monocyte precursors. Thus, expression of putative P2-purinergic receptors for ATP appears to precede expression of other receptor types known to activate the inositol phospholipid signaling cascades in terminally differentiated phagocytes.
Assuntos
Trifosfato de Adenosina/fisiologia , Cálcio/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Leucócitos Mononucleares/metabolismo , Neutrófilos/metabolismo , Fagócitos/metabolismo , Medula Óssea , Linhagem Celular , Transformação Celular Neoplásica/metabolismo , Citosol/metabolismo , Espaço Extracelular/fisiologia , Humanos , Leucemia Mieloide/metabolismo , Células-Tronco Neoplásicas/metabolismoRESUMO
During a 5-year period colon tumors induced by 1,2-dimethylhydrazine dihydrochloride treatment in NMRI mice were transplanted sc into isologous mice to obtain transplantable tumor lines that might serve as experimental models for human colon cancer. The resultant 17 serially transplantable tumor lines were adenocarcinomas varying in degree of differentiation and mucin production. Two of the lines passaged for 5 years and used in chemotherapy studies have shown histologic progression toward dedifferentiation with concomitant acceleration of growth rate.
Assuntos
Adenocarcinoma/patologia , Neoplasias do Colo/patologia , Adenocarcinoma/metabolismo , Animais , Diferenciação Celular , Neoplasias do Colo/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos , Mucinas/biossíntese , Transplante de Neoplasias , Neoplasias Experimentais/patologia , Fatores de Tempo , Transplante IsogênicoRESUMO
PURPOSE: Retrospectively evaluate the safety, feasibility and efficacy of concomitant chemoradiotherapy after induction chemotherapy by docetaxel, cisplatin and 5-fluoro-uracil for locally advanced head and neck cancers. PATIENTS AND METHODS: Patients' data from three radiotherapy centres in South of France, with locally advanced head and neck cancers, and treated between December 2007 and July 2013 by concomitant chemoradiotherapy, after induction chemotherapy by docetaxel, cisplatin and 5-fluoro-uracil, were analysed. Adverse effects were graduated according to CTCAE v3.0 criteria. Overall survival and disease-free survival were calculated according to Kaplan-Meier method. RESULTS: One hundred and sixty-eight patients, mostly oropharynx (38%) T4 (46%) N2 (54%) tumors, received, after induction chemotherapy by docetaxel, cisplatin and 5-fluoro-uracil, a concomitant chemoradiotherapy with platin or cetuximab, which delivered 66 to 70Gy. Grade 3-4 adverse effects were less frequent in the group of patients who received cisplatin (with or withour 5-fluoro-uracil) at 100mg/m(2) each 21 days compared to cetuximab (radiomucositis: 32.5% vs 61%, P=0.018; radioepithelitis: 13% vs 61 %, P<0.0001). Chemopotentiation was incomplete for 21% of patients without impacting survival. Two years overall survival and disease-free survival were respectively of 81% and 64%. Lymph nodes status and WHO status significantly influenced these survivals (overall survival 84% if N<3 vs 56% if N3, P=0.017 and 85 % if WHO status ≤ 1 vs 50% if WHO status>1, P=0.006; disease-free survival 66% if N<3 vs 47% if N3, P=0.046). CONCLUSION: The association of induction chemotherapy by docetaxel, cisplatin and 5-fluoro-uracil and concomitant chemoradiotherapy shows satisfying results with an acceptable toxicity. The terms of the chemopotentiation and its superiority to a single concomitant chemoradiotherapy treatment still remain to be clarified.
Assuntos
Quimiorradioterapia , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/terapia , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cetuximab/uso terapêutico , Cisplatino/administração & dosagem , Intervalo Livre de Doença , Docetaxel , Feminino , Fluoruracila/administração & dosagem , França/epidemiologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Estudos Retrospectivos , Taxoides/administração & dosagem , Adulto JovemRESUMO
In breast cancer, radiotherapy is an essential component of the treatment. After conservative surgery for an infiltrating carcinoma, radiotherapy must be systematically performed, regardless of the characteristics of the disease, because it decreases the rate of local recurrence and by this way, specific mortality. Partial breast irradiation could not be proposed routinely but only in very selected and informed patients. For ductal carcinoma in situ, adjuvant radiotherapy must be also systematically performed after lumpectomy. After mastectomy, chest wall irradiation is required for pT3-T4 tumours and if there is an axillary nodal involvement, whatever the number of involved lymph nodes. After neo-adjuvant chemotherapy and mastectomy, in case of pN0 disease, chest wall irradiation is recommended if there is a clinically or radiologically T3-T4 or node positive disease before chemotherapy. Axillary irradiation is recommended only if there is no axillary surgical dissection and a positive sentinel lymph node. Supra and infra-clavicular irradiation is advised in case of positive axillary nodes. Internal mammary irradiation must be discussed case by case, according to the benefit/risk ratio (cardiac toxicity). Dose to the chest wall or the breast must be between 45-50Gy with a conventional fractionation. A boost dose over the tumour bed is required if the patient is younger than 60 years old. Hypofractionation (42.5 Gy in 16 fractions, or 41.6 Gy en 13 or 40 Gy en 15) is possible after tumorectomy and if a nodal irradiation is not mandatory. Delineation of the breast, the chest wall and the nodal areas are based on clinical and radiological evaluations. 3D-conformal irradiation is the recommended technique, intensity-modulated radiotherapy must be proposed only in case of specific clinical situations. Respiratory gating could be useful to decrease the cardiac dose. Concomitant administration of chemotherapy in unadvised, but hormonal treatment could be start with radiotherapy.
Assuntos
Neoplasias da Mama/radioterapia , Carcinoma/radioterapia , Adulto , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Carcinoma/tratamento farmacológico , Carcinoma/cirurgia , Carcinoma Intraductal não Infiltrante/radioterapia , Carcinoma Intraductal não Infiltrante/cirurgia , Quimiorradioterapia , Terapia Combinada , Fracionamento da Dose de Radiação , Feminino , Coração/efeitos da radiação , Humanos , Irradiação Linfática , Metástase Linfática , Mastectomia Segmentar , Pessoa de Meia-Idade , Órgãos em Risco , Lesões por Radiação/prevenção & controle , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia Adjuvante/efeitos adversos , Radioterapia Adjuvante/métodos , Radioterapia Adjuvante/normas , Radioterapia Guiada por Imagem/métodos , Parede Torácica/efeitos da radiaçãoRESUMO
A new archaeal isolate has been reported that is capable of growing at up to 121 degrees C. The hyperthermophile, dubbed strain 121, grows chemoautotrophically using formate as an electron donor and FeIII as an electron acceptor and is closely related to members of the archaeal genera Pyrodictium and Pyrobaculum. Although the reported maximum growth temperature of strain 121 is 8 degrees C higher than the previous record holder (Pyrolobus fumarii; Tmax = 113 degrees C), the two organisms have virtually the same optimal growth temperatures.
Assuntos
Archaea/isolamento & purificação , Archaea/fisiologia , Estabilidade Enzimática , Temperatura Alta , Archaea/crescimento & desenvolvimento , Archaea/metabolismo , Compostos Férricos/metabolismo , Formiatos/metabolismo , OxirreduçãoRESUMO
We have previously determined that human neutrophils and monocytes, as well as neutrophil/monocyte progenitor cells, express a subtype of P2-purinergic receptors (for ATP) which activate the inositol phospholipid signalling system. In the present study, membranes prepared from HL-60 promyelocytic leukemia cells were used to examine the mechanism by which these ATP receptors activate phosphatidylinositol-specific phospholipase C (PI-PLC) under defined in vitro conditions. Micromolar concentrations of the receptor agonists ATP, UTP, and ATP gamma S stimulated the GTP-dependent formation of inositol bisphosphate (IP2) and inositol trisphosphate (IP3) in washed membranes prepared from undifferentiated HL-60 cells prelabeled with [3H]inositol. The stimulatory effects of these nucleotides on PI-PLC appeared to be mediated through a GTP binding protein since minimal inositol polyphosphate accumulation was observed in the absence of guanine nucleotides. The increased inositol polyphosphate formation triggered by these nucleotide receptor agonists did not result from inhibition of GTP breakdown. Neither was it a consequence of increased [3H]polyphosphatidylinositol levels resulting from enhanced activity of membrane-associated PI- or PIP-kinases. Instead, the stimulated phospholipase activity was apparently receptor-mediated. The rank order of potency observed in these in vitro membrane assays (ATP = UTP greater than ATP gamma S much greater than TTP greater than CTP much greater than beta, gamma-CH-ATP) was similar to that observed with intact HL-60 cells. This order of potency appears to distinguish the P2-purinergic receptors expressed by human phagocytic leukocytes from the P2 gamma-purinergic receptors which activate PI-PLC in turkey erythrocyte membranes.
Assuntos
Guanosina Trifosfato/farmacologia , Translocases Mitocondriais de ADP e ATP/metabolismo , Nucleotidiltransferases/metabolismo , Fosfatos de Fosfatidilinositol , Diester Fosfórico Hidrolases/metabolismo , Receptores Citoplasmáticos e Nucleares , Receptores Purinérgicos/metabolismo , Animais , Membrana Celular/enzimologia , Ativação Enzimática , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Humanos , Monócitos/efeitos dos fármacos , Monócitos/enzimologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Fosfatidilinositol Diacilglicerol-Liase , Fosfatidilinositóis/farmacologia , Fosfoinositídeo Fosfolipase C , Fosforilação , Células Tumorais Cultivadas , PerusRESUMO
K-m values of beta-N-acetylglucosaminidase (2-acetamido-2-deoxy-beta-D-glucoside acetamidodeoxyglucohydrolase EC 3.2.1.30), beta-N-acetylgalactosaminidase (EC 3.2.1.53), beta-galactosidase (beta-D-galactoside galactohydrolase EC 3.2.1.23) and alpha-L-fucosidase (alpha-L-fucoside fucohydrolase EC 3.2.1.51) of distal colonic tumours, induced in rats by 1,2-dimethylhydrazine, were found to be significantly different compared with the values for the enzymes of the colonic mucosa of the control and tumour-bearing animals and of the proximal colonic tumours. The inhibition kinetics data also showed a significant difference between the enzymes of the distal colon tumours and of other experimental tissues. The data on the effect of pH on enzyme kinetics (pK values) showed no significant difference in the catalytic groups of the active centres of enzymes from tumours and from the control colonic mucosa. Tumour beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase compared with the enzymes from other experimental tissues were found to be different in their thermal inactivation kinetics. K-m values of 14 days old foetal intestinal beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase were significantly different from the values obtained for the adult mucosal enzymes but were similar to those of the distal colonic tumour enzymes.
Assuntos
Colo/enzimologia , Neoplasias do Colo/enzimologia , Glicosídeo Hidrolases/metabolismo , Acetilgalactosamina , Acetilglucosamina , Animais , Neoplasias do Colo/induzido quimicamente , Dimetilidrazinas , Feto , Fucose/farmacologia , Galactose/farmacologia , Galactosidases/metabolismo , Idade Gestacional , Hexosaminidases/metabolismo , Concentração de Íons de Hidrogênio , Mucosa Intestinal/enzimologia , Cinética , Lactonas/farmacologia , Nitrofenóis , Ratos , Estereoisomerismo , alfa-L-Fucosidase/metabolismoRESUMO
An adenovirus 5 vector containing wild-type p53 cDNA (Ad5-p53) and a cytomegalovirus promoter was used to generate p53 transgene expression. Control vector (Ad5-pA) contained the poly-adenosine sequence. PC3 cells (2 x 10(6)) were injected s.c. into the legs of nude mice. Treatment with Ad5-p53 was initiated at a tumor volume of 200 mm3. Three intratumoral injections (days 1, 4, and 7) were given with 3 x 10(8) plaque-forming units, followed by 5 Gy pelvic irradiation (day 8) in one fraction using a cobalt-60 source. Tumor volume measurements were obtained every 2 days. LNCaP cells (2 x 10(6)) were injected orthotopically into the prostates of nude mice, and tumor weight was approximated using serum prostate-specific antigen (PSA) obtained from weekly tail vein bleedings. The target PSA for the start of the studies was 5 ng/ml. The intraprostatic injections of Ad5-p53 were done twice (days 1 and 2) and followed by 5 Gy pelvic irradiation on day 3. The PC3 tumor volume growth curves were log transformed and fitted using linear regression. The times (in days) for the tumors to reach 500 mm3 were calculated as 10.7 +/- 0.7 (+/- SE) for the saline control (no virus), 9.8 +/- 2.1 for Ad5-pA, 15.6 +/- 1.6 for Ad5-p53, 14.6 +/- 1.5 radiation therapy (RT; 5 Gy), 14.6 +/- 1.5 for Ad5-pA plus RT, and 31.4 +/- 5.3 for Ad5-p53 plus RT. The Ad5-p53 plus RT times were significantly different from the other groups. An enhancement factor of 3.4 was calculated, indicating supra-additivity. LNCaP tumor growth was determined via weekly serum PSA measurements. Treatment failure was determined using two PSA-based methods; a serum PSA of > 1.5 ng/ml or two rises in PSA during 6 weeks posttreatment. The results were similar using either end point. Treatment with Ad5-p53 plus 5 Gy resulted in significantly fewer PSA failures (<30%), as compared with Ad5-p53 alone (64-73%) and the other controls (approximately 80-100%) These results are also consistent with a supra-additive inhibition of tumor growth. Tumor growth in vivo was inhibited supra-additively when p53null and p53wildtype prostate tumors were treated with Ad5-p53 and 5 Gy radiation.
Assuntos
Adenoviridae/genética , Genes p53 , Terapia Genética , Neoplasias da Próstata/radioterapia , Animais , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias da Próstata/patologia , Tolerância a Radiação , Células Tumorais CultivadasRESUMO
In previous studies we have demonstrated that extracellular ATP (and UTP), acting through P2-purinergic receptors, can stimulate the inositol phospholipid signaling system in neutrophils and monocytes, as well as in neutrophil/monocyte progenitor cells. In this study we have examined the ability of extracellular nucleotides to modulate the phenotype of myelomonocytic progenitor cells. As model systems, we utilized the established HL-60 promyelocytic and U937 promonocytic human cell lines which were cultured in the continuous presence of nucleotides known to be potent agonists for P2-purinergic receptors. When cultured for 5 days with ATP gamma S (a phosphatase resistant analog of ATP) plus 10% fetal bovine serum, both HL-60 cells and U937 cells expressed several (but not all) phenotypic characteristics of differentiated phagocytes. In HL-60 cells these characteristics were (1) increased intracellular calcium mobilization in response to formylated chemotactic peptides, (2) a reduction in cell size with a decreased nuclear/cytoplasmic ratio, (3) a sharply reduced rate of proliferation, (4) a reduction in the percentage of cells expressing surface transferrin receptors, and (5) an increase in the percentage of cells expressing the type 1 complement receptor (CR1). In U937 cells these characteristics were (1) increased intracellular calcium mobilization in response to formylated chemotactic peptides and platelet activating factor, (2) a reduced rate of proliferation, (3) a reduction in the percentage of cells expressing surface transferrin receptors, and (4) increases in the percentage of cells expressing both type 1 (CR1) and type 3 (CR3) complement receptors. During the first 12-24 hr after exposure to ATP gamma S, HL-60 cells showed no obvious changes in morphology, viability, or the levels of beta-actin mRNA, but did show (1) a 4-fold increase in chemotactic peptide-induced Ca2+ mobilization, and (2) a greater than 90% decrease in c-myc mRNA levels. Significantly, when HL-60 cells were treated under serum-free conditions, the ability of ATP to enhance expression of functional FMLP receptors could be dissociated from the inhibitory effects of adenine nucleotides on cell proliferation observed in serum containing media. Moreover, treatment of serum-free HL-60 cultures with UTP, another P2-purinergic receptor agonist, also resulted in enhanced expression of functional FMLP receptors.
Assuntos
Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/farmacologia , Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , Fagócitos/citologia , Receptores Purinérgicos/fisiologia , Uridina Trifosfato/farmacologia , Actinas/genética , Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Genes myc/efeitos dos fármacos , Humanos , Cinética , Leucemia Promielocítica Aguda , Linfoma Difuso de Grandes Células B , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Fagócitos/efeitos dos fármacos , Fenótipo , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , Superóxidos/metabolismo , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
We present the development and application of a generic analysis scheme for the measurement of neutrino spectra with the IceCube detector. This scheme is based on regularized unfolding, preceded by an event selection which uses a Minimum Redundancy Maximum Relevance algorithm to select the relevant variables and a random forest for the classification of events. The analysis has been developed using IceCube data from the 59-string configuration of the detector. 27,771 neutrino candidates were detected in 346 days of livetime. A rejection of 99.9999 % of the atmospheric muon background is achieved. The energy spectrum of the atmospheric neutrino flux is obtained using the TRUEE unfolding program. The unfolded spectrum of atmospheric muon neutrinos covers an energy range from 100 GeV to 1 PeV. Compared to the previous measurement using the detector in the 40-string configuration, the analysis presented here, extends the upper end of the atmospheric neutrino spectrum by more than a factor of two, reaching an energy region that has not been previously accessed by spectral measurements.
RESUMO
Little has been written about the cells here termed cerebellar melanoneurons. This paper describes and illustrates their cytologic features and topographic relationships. In the human brain these large pigmented neurons are scattered in a narrow layer near the lateral wall, dorsal angle and roof of the fourth ventricle. They form an inconspicuous part (group A4) of the system of catecholamine, neuromelanin-containing cells well known in the brain stem. Rostrally, a few of them provide a tenuous continuity with the locus ceruleus but topographically the two nuclei are independent. With ordinary stains the cerebellar cells can be seen as early as the 26th week of gestation (the earliest period examined). Brown neuromelanin granules do not appear until two and a half years of age but argentaffin granules, foreshadowing the production of pigment, are found in increasing numbers in the fetal and postnatal period. Homologues of the human cerebellar cells are reported in two species of monkey, Macaca nemestrina and Lagothrix sp. Neuromelanin, not previously observed in non-human cerebellar cells, occurs in M. mulatta and M. nemestrina. The proximity of the cerebellar melanoneurons to the ventricle raises the possibility that they are related to functions of the ependyma, or that they influence, or are affected by, constituents of the cerebrospinal fluid. The pathologic changes they undergo in Parkinson's disease and other disorders are to be described elsewhere.
Assuntos
Cerebelo/citologia , Adolescente , Adulto , Idoso , Animais , Catecolaminas/análise , Cerebelo/análise , Criança , Epêndima/citologia , Humanos , Locus Cerúleo/análise , Locus Cerúleo/citologia , Macaca mulatta/ultraestrutura , Macaca nemestrina/ultraestrutura , Masculino , Melaninas , Pessoa de Meia-Idade , Neurônios/análise , Neurônios/ultraestrutura , Substância Negra/análise , Substância Negra/citologiaRESUMO
Ornithine decarboxylase, rate-limiting in polyamine formation, has been found to be necessary for the development of vasogenic edema after cryogenic cerebral injury and is postulated to be of importance in late ischemic brain edema formation. Ornithine decarboxylase activity and accompanying edema was studied after transient cerebral ischemia in Mongolian gerbils. Bilateral carotid artery occlusion was utilized to produce dense forebrain ischemia. After 4 h of reperfusion a significant elevation in ornithine decarboxylase activity was present (72.5 +/- 24.7 vs 8.5 +/- 2 pmoles/mg protein/h, p less than 0.05). Immunohistochemical localization of ornithine decarboxylase indicated its presence in cortical neurons of ischemic gerbils. This was typically located in the perinuclear cytoplasm and extended into proximal dendrites. Nonischemic animals did not contain ornithine decarboxylase immunoreactivity. These studies show the presence and location of ornithine decarboxylase in cerebral tissue subjected to transient ischemia. The increase in this marker of polyamine activity paralleled previous studies in this model of cerebral edema formation and reperfusion deficit in blood flow and evoked potential, suggesting that ornithine decarboxylase is a marker for and may be associated with those late metabolic events leading to progressive functional deterioration after incomplete cerebral ischemia.