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1.
Chem Sci ; 13(6): 1789-1800, 2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35282626

RESUMO

We investigate interatomic Coulombic decay in NeKr dimers after neon inner-valence photoionization [Ne+(2s-1)] using a synchrotron light source. We measure with high energy resolution the two singly charged ions of the Coulomb-exploding dimer dication and the photoelectron in coincidence. By carefully tracing the post-collision interaction between the photoelectron and the emitted ICD electron we are able to probe the temporal evolution of the state as it decays. Although the ionizing light pulses are 80 picoseconds long, we determine the lifetime of the intermediate dimer cation state and visualize the contraction of the nuclear structure on the femtosecond time scale.

2.
Ann Nucl Med ; 16(7): 503-6, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12508845

RESUMO

OBJECTIVE: The aim of this study was to evaluate L-3[123I]-iodo-alpha-methyl tyrosine (IMT)-SPECT and FDG-PET in pulmonary lesions suspected to be lung cancer. METHODS: Whole body PET (measured transmission corrected emission scans) was performed 45 minutes after i.v. injection of 222-370 MBq (6-10 mCi) 18F-FDG on a Siemens PET scanner (ECAT EXACT 47) including 5-6 bed positions. 123I-IMT-SPECT (chest) was performed after injection of 370 MBq (10 mCi) with a dual head camera (Picker Prism 2000) and commercially available reconstruction algorithms. Ten patients (6 male and 4 female) with suspected lung cancer were investigated. The results were compared to histological findings after surgery or bronchoscopic biopsies and CT. RESULTS: 123I-IMT-SPECT and FDG-PET were able to detect all 9 cases of lung cancer (1-8 cm in diameter). One case was true negative. Both imaging methods were true positive with respect to mediastinal lymph node metastases in one patient. The tumor/background ratio was higher with PET (8.20 vs. 2.84). CONCLUSION: Despite the limited number of patients it may be concluded that IMT-SPECT as well as FDG-PET are suited to correctly diagnose lung cancer. Nevertheless, FDG-PET, if available, seems to be better suited because of the higher tumor/background ratio and better resolution.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma de Células Pequenas/diagnóstico por imagem , Fluordesoxiglucose F18 , Neoplasias Pulmonares/diagnóstico por imagem , Metiltirosinas , Tomografia Computadorizada de Emissão/métodos , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Contagem Corporal Total/métodos
3.
Breast Cancer Res Treat ; 63(3): 199-212, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11110054

RESUMO

We have investigated the effects of transient Bcl-2 down-regulation induced by the Bcl-2 antisense oligodeoxynucleotide (ODN) G3139 (Genta Incorporated) in high Bcl-2 protein expressing, estrogen receptor (ER) positive MCF-7 and low Bcl-2 expressing, ER negative MDA435/LCC6 human breast cancer cells. Treatment with Bcl-2 antisense ODN in vitro caused > 80% reduction of Bcl-2 protein levels in a sequence specific manner for both cell lines. Maximum mRNA reduction was achieved within 24 h of the first antisense ODN exposure whereas full protein down-regulation required antisense exposure over 48 h. This Bcl-2 reduction was associated with 80-95% loss of viable cells compared to untreated cells. Similar cytotoxic effects were observed in both cell lines despite a nine-fold intrinsic difference in Bcl-2 protein expression suggesting that the relative degree of down-regulation of Bcl-2 is more important than the absolute reduction. Cell death associated with G3139 exposure exhibited properties indicative of apoptosis such as mitochondrial membrane depolarization and caspase activation. Combined treatment with G3139 and cytotoxic agents resulted in additive cytotoxicity in both cell lines. However, under most conditions studied, the direct cytotoxic activity of G3139 antisense was not synergistic with the cytotoxic agents. These results suggest that while Bcl-2 clearly constitutes an attractive therapeutic target due to its role in regulating apoptosis in breast cancer cells, additional mechanisms are important in the control of apoptosis arising from exposure to anticancer agents in vitro.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Oligonucleotídeos Antissenso/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Apoptose , Neoplasias da Mama/metabolismo , Feminino , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , RNA Mensageiro/análise , Receptores de Estrogênio/análise , Células Tumorais Cultivadas
4.
Cytometry ; 40(4): 346-52, 2000 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-10918285

RESUMO

BACKGROUND: A protocol to measure a wide range of Bcl-2 protein expression using quantitative fluorescence cytometry (QFCM) in different cell types was developed for use with flow cytometry. Bcl-2 measurements obtained by flow cytometry were correlated with Western blot Bcl-2 measurements to confirm specificity of the Bcl-2-FITC staining. This protocol was applied to measure absolute levels of Bcl-2 protein in different tumor cell lines including Bcl-2-transfected breast carcinoma cell lines and in peripheral blood lymphocytes (PBL). METHODS: HL-60, K562, DOHH2, Jurkat, MDA435/LCC6, MCF7 cell lines, and PBL derived from normal donors were fixed, permeabilized, stained with anti-Bcl-2-FITC antibody and evaluated by QFCM. In parallel, the same cells were evaluated for Bcl-2 protein expression by Western blot analysis. Mitochondrial localization of anti-Bcl-2-FITC antibody inside cells was confirmed using fluorescence imaging microscopy. RESULTS: Bcl-2 expression in different cell types could be accurately quantified based on antibody-binding capacity (ABC) ranging from 12.6 x 10(3) antibody-binding sites in HL-60 cells to 1.64 x 10(6) antibody-binding sites in a Bcl-2-transfected MDA435/LCC6 clone. The data from flow cytometry analysis correlated well with Western analysis (R(2) = 0.78). Bcl-2-FITC staining colocalized with dyes specific for mitochondria. CONCLUSIONS: The Bcl-2 staining protocol described here was shown to be specific, sensitive, and it was able to provide higher resolution as well as more reproducible quantitation of Bcl-2 protein content in cells when compared with Western blot methods. Quantitation of Bcl-2 content in cells by QFCM may be useful for monitoring Bcl-2 expression in cells undergoing various treatments in vitro and in vivo.


Assuntos
Neoplasias da Mama/química , Citometria por Imagem/métodos , Proteínas Proto-Oncogênicas c-bcl-2/análise , Western Blotting/métodos , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Citometria de Fluxo/métodos , Expressão Gênica , Humanos , Imunoglobulina G/análise , Microscopia de Fluorescência , Mitocôndrias/química , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transfecção/genética , Células Tumorais Cultivadas
5.
Eur J Nucl Med ; 27(2): 123-30, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10755716

RESUMO

The aim of this study was to determine the maximum tolerated dose of rhenium-188 hydroxyethylidene diphosphonate (HEDP) in prostate cancer patients with osseous metastases who are suffering from bone pain. Twenty-two patients received a single injection of escalating doses of carrier-added 188Re-HEDP [1.3 GBq (35 mCi), 2.6 GBq (70 mCi), 3.3 GBq (90 mCi) and 4.4 GBq (120 mCi)]. Blood counts and biochemical parameters were measured weekly over a period of 8 weeks. Haematological toxicity (WHO grading) of grade 3 or 4 was considered unacceptable. Clinical follow-up studies including methods of pain documentation (medication, pain diary) were performed for 6 months after treatment. In the 1.3-GBq group, no haematological toxicity was observed. First haematotoxic results were noted in those patients with a dose of 2.6 GBq 188Re-HEDP. In the 3.3-GBq group, one patient showed a reversible thrombopenia of grade 1, one a reversible thrombopenia of grade 2 and three a reversible leukopenia of grade 1. In the 4.4-GBq group, thrombopenia of grades 3 and 4 was observed in one and two patients (baseline thrombocyte count <200x10(9)/l), respectively, and leukopenia of grade 3 was documented in one patient. The overall nadir of thrombopenia was at week 4. The individual, maximum percentage decrease in thrombocytes in the 1.3-, 2.6-, 3.3- and 4.4-GBq groups was 17%, 40%, 60% and 86%, respectively. In two patients, a transient increase in serum creatinine was observed (max. 1.6 mg/dl). Pain palliation was reported by 64% of patients, with a mean duration of 7.5 weeks. The response rate seemed to increase with higher doses, reaching 75% in the 4.4-GBq group. It is concluded that in prostate cancer patients, the maximum tolerated dose of 188Re-HEDP is 3.3 GBq if the baseline thrombocyte count is below 200x10(9)/l. In patients with thrombocyte counts significantly above 200x10(9)/l, a dose of 4.4 GBq might be tolerable. Thrombo- and leukopenia are the most important side-effects. Pain palliation can be achieved in 60%-75% of patients receiving a dose of 2.6 GBq or more of 188Re-HEDP. Studies in a larger patient population are warranted to evaluate further the palliative effect of 188Re-HEDP.


Assuntos
Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Ácido Etidrônico/uso terapêutico , Cuidados Paliativos , Neoplasias da Próstata/fisiopatologia , Radioisótopos/uso terapêutico , Rênio/uso terapêutico , Relação Dose-Resposta à Radiação , Humanos , Masculino , Medição da Dor , Dor Intratável/radioterapia , Dosagem Radioterapêutica
6.
Nucl Med Biol ; 25(7): 621-31, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9804043

RESUMO

Either radiolabeled Tc-99m- or Re-188-labeled MAG3-4-nitrophenylester or unlabeled Bz-MAG3-4-nitrophenylester was reacted with amines and peptides to follow a pre- or a postconjugate radiolabeling route, respectively. The model compounds were N'-t-butyloxycarbonyl-1,6-diaminohexane (DH-Boc) and a Lys-protected derivative of the somatostatin analog RC-160 (cyclic D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2). In the case of labeling DH-Boc, both the preconjugate labeling and the postconjugate labeling were found by using analytical HPLC to provide identical radiolabeled compounds regardless whether Re-188 or Tc-99m was used. The results are supported by infrared and mass-spectral data obtained from compounds synthesized using stable rhenium. The 188Re- or 99mTc-MAG3-RC-160 somatostatin analog were synthesized following the preconjugate labeling route and subsequent removal of the protecting group. Biodistributions of 188Re-and 99mTc-MAG3-RC-160 were evaluated in normal and tumor-bearing mice, and were similar to those of radioiodinated 131-RC-160. All radiolabeled analogs of RC-160 were rapidly cleared from the blood and were excreted through the hepatobiliary system with very little normal organ uptake. The tumor uptake (PC-3, human prostate adenocarcinoma) of systemically administered Re-188-MAG3-RC160 was very low, and it reached only 0.28% injected dose/g (%IDg) at 24 h postinjection, similar to what was obtained with I-131-RC-160. Intratumor injections resulted in significant tumor retentions (9.3% ID/g at 24 h).


Assuntos
Aminas/química , Oligopeptídeos/química , Compostos Organometálicos/química , Tecnécio Tc 99m Mertiatida/química , Animais , Cromatografia Líquida de Alta Pressão , Diaminas/química , Feminino , Ésteres do Ácido Fórmico/química , Camundongos , Camundongos Nus , Oligopeptídeos/farmacocinética , Compostos Organometálicos/farmacocinética , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Somatostatina/análogos & derivados , Somatostatina/química , Somatostatina/farmacocinética , Tecnécio Tc 99m Mertiatida/farmacocinética , Fatores de Tempo , Distribuição Tecidual
7.
Rev Med Brux ; 19(2): 73-5, 1998 Apr.
Artigo em Francês | MEDLINE | ID: mdl-9643086

RESUMO

We report on a case of a 66 years-old patient suffering weight loss and lumbar pain, localized at L2-L3. A spondylodiscitis was revealed by CT and MRI; intervertebral disc puncture was positive for Pneumococcus Pneumoniae. The clinical evolution was good with the anti-bacterial treatment, while the patient developed a synostosis L2-L3. Incidence, bacteriology, imaging and therapy of spondylodicitis are discussed.


Assuntos
Discite/diagnóstico , Vértebras Lombares , Infecções Pneumocócicas/diagnóstico , Idoso , Antibacterianos/uso terapêutico , Discite/tratamento farmacológico , Humanos , Imageamento por Ressonância Magnética , Masculino , Infecções Pneumocócicas/tratamento farmacológico , Punção Espinal , Tomografia Computadorizada por Raios X
8.
Sci Total Environ ; 93: 489-98, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2360029

RESUMO

This paper presents the final results of the application of a probabilistic approach for evaluating the water quality impact of highway stormwater runoff to receiving waters. A brief review of the development of the probabilistic characterization of runoff water quality data is presented along with a description of the probabilistic stream impact method. In this paper we present the interactive Decision Support program that takes the procedure user through the Federal Highway Administration's highway runoff analysis procedure. The procedure requires the input of fixed site data, rainfall and streamflow statistics, highway runoff water quality, and target concentrations. The methodology user is provided guidance in entering the required data. Output of the procedure is a return frequency of the exceedances of the target concentration. This methodology is intended for planning level analyses.


Assuntos
Meios de Transporte , Poluição Química da Água/prevenção & controle , Monitoramento Ambiental/métodos , Órgãos Governamentais , Chuva , Estados Unidos , Poluição Química da Água/análise , Tempo (Meteorologia)
9.
Ann N Y Acad Sci ; 383: 295-306, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-6807167

RESUMO

The data suggest that in the absence of the testis: (1) testosterone can maintain both FSH and LH concentrations chronically within the physiological range; (2) that estradiol preferentially suppresses plasma LH concentration, indicating that the androgenic component of testosterone modulates FSH secretion; and (3) that subphysiological testosterone concentrations accompanied by physiological estradiol levels permit FSH to escape to midcastrate levels while maintaining LH concentration at intact levels. An alteration in the testosterone: estradiol ratio can account for a selective FSH elevation when testosterone production is low. The data provide an alternative explanation for the inhibin phenomenon.


Assuntos
Estradiol/sangue , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Proteínas/fisiologia , Hormônios Testiculares/fisiologia , Testosterona/sangue , Animais , Castração , Relação Dose-Resposta a Droga , Estradiol/farmacologia , Hipotálamo/análise , Inibinas , Masculino , Hormônios Liberadores de Hormônios Hipofisários/análise , Ratos , Testosterona/farmacologia
11.
Science ; 157(3794): 1267-9, 1967 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-17737430

RESUMO

Electric discharges between free-falling drops have been observed and studied quantitatively in the laboratory. These data and information from terrestrial thunderstorms suggest that augmentation of the UHF temperature of thunderstorms by discharges could amount to 117 degrees K. If similar discharges occurred in the atmosphere or on the surface (or in both regions) of Venus, 1.4 x 10(6) discharges per second per square meter would be required to produce the microwave temperature observed (approximately 650 degrees K). It is not probable that such radiation supplies the whole microwave temperature observed; some fraction must be true thermal radiation as described by Plummer and Strong (9), in which case the probable number of required discharges is reduced accordingly.

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