Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Data Brief ; 48: 109105, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37095754

RESUMO

The data presented in this article are related to the research paper entitled "Observation of night-time emissions of the Earth in the near UV range from the International Space Station with the Mini-EUSO detector" (Remote Sensing of Environment, Volume 284, January 2023, 113336, https://doi.org/10.1016/j.rse.2022.113336). The data have been acquired with the Mini-EUSO detector, an UV telescope operating in the range 290-430 nm and located inside the International Space Station. The detector was launched in August 2019, and it has started operations from the nadir-facing UV-transparent window in the Russian Zvezda module in October 2019. The data presented here refer to 32 sessions acquired between 2019-11-19 and 2021-05-06. The instrument consists of a Fresnel-lens optical system and a focal surface composed of 36 multi-anode photomultiplier tubes, each with 64 channels, for a total of 2304 channels with single photon counting sensitivity. The telescope, with a square field-of-view of 44°, has a spatial resolution on the Earth surface of 6.3 km and saves triggered transient phenomena with a temporal resolution of 2.5 µs and 320 µs. The telescope also operates in continuous acquisition at a 40.96 ms scale. In this article, large-area night-time UV maps obtained processing the 40.96 ms data, taking averages over regions of some specific geographical areas (e.g., Europe, North America) and over the entire globe, are presented. Data are binned into 0.1° × 0.1° or 0.05° × 0.05° cells (depending on the scale of the map) over the Earth's surface. Raw data are made available in the form of tables (latitude, longitude, counts) and .kmz files (containing the .png images). These are - to the best of our knowledge - the highest sensitivity data in this wavelength range and can be of use to various disciplines.

2.
Phys Med Biol ; 62(10): 4031-4045, 2017 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-28287399

RESUMO

MR-guided high-dose-rate (HDR) brachytherapy has gained increasing interest as a treatment for patients with localized prostate cancer because of the superior value of MRI for tumor and surrounding tissues localization. To enable needle insertion into the prostate with the patient in the MR bore, a single needle MR-compatible robotic system involving needle-by-needle dose delivery has been developed at our institution. Throughout the intervention, dose delivery may be impaired by: (1) sub-optimal needle positioning caused by e.g. needle bending, (2) intra-operative internal organ motion such as prostate rotations or swelling, or intra-procedural rectum or bladder filling. This may result in failure to reach clinical constraints. To assess the first aforementioned challenge, a recent study from our research group demonstrated that the deposited dose may be greatly improved by real-time adaptive planning with feedback on the actual needle positioning. However, the needle insertion sequence is left to the doctor and therefore, this may result in sub-optimal dose delivery. In this manuscript, a new method is proposed to determine and update automatically the needle insertion sequence. This strategy is based on the determination of the most sensitive needle track. The sensitivity of a needle track is defined as its impact on the dose distribution in case of sub-optimal positioning. A stochastic criterion is thus presented to determine each needle track sensitivity based on needle insertion simulations. To assess the proposed sequencing strategy, HDR prostate brachytherapy was simulated on 11 patients with varying number of needle insertions. Sub-optimal needle positioning was simulated at each insertion (modeled by typical random angulation errors). In 91% of the scenarios, the dose distribution improved when the needle was inserted into the most compared to the least sensitive needle track. The computation time for sequencing was less than 6 s per needle track. The proposed needle insertion sequencing can therefore assist in delivering an optimal dose in HDR prostate brachytherapy.


Assuntos
Braquiterapia/instrumentação , Imageamento por Ressonância Magnética , Agulhas , Neoplasias da Próstata/radioterapia , Doses de Radiação , Radioterapia Guiada por Imagem/instrumentação , Procedimentos Cirúrgicos Robóticos/instrumentação , Humanos , Masculino , Posicionamento do Paciente , Neoplasias da Próstata/diagnóstico por imagem , Dosagem Radioterapêutica , Fatores de Tempo
3.
Phys Med Biol ; 61(5): 2177-95, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26907732

RESUMO

The development of magnetic resonance (MR) guided high dose rate (HDR) brachytherapy for prostate cancer has gained increasing interest for delivering a high tumor dose safely in a single fraction. To support needle placement in the limited workspace inside the closed-bore MRI, a single-needle MR-compatible robot is currently under development at the University Medical Center Utrecht (UMCU). This robotic device taps the needle in a divergent way from a single rotation point into the prostate. With this setup, it is warranted to deliver the irradiation dose by successive insertions of the needle. Although robot-assisted needle placement is expected to be more accurate than manual template-guided insertion, needle positioning errors may occur and are likely to modify the pre-planned dose distribution.In this paper, we propose a dose plan adaptation strategy for HDR prostate brachytherapy with feedback on the needle position: a dose plan is made at the beginning of the interventional procedure and updated after each needle insertion in order to compensate for possible needle positioning errors. The introduced procedure can be used with the single needle MR-compatible robot developed at the UMCU. The proposed feedback strategy was tested by simulating complete HDR procedures with and without feedback on eight patients with different numbers of needle insertions (varying from 4 to 12). In of the cases tested, the number of clinically acceptable plans obtained at the end of the procedure was larger with feedback compared to the situation without feedback. Furthermore, the computation time of the feedback between each insertion was below 100 s which makes it eligible for intra-operative use.


Assuntos
Braquiterapia/métodos , Neoplasias da Próstata/radioterapia , Erros de Configuração em Radioterapia/prevenção & controle , Radioterapia Guiada por Imagem/métodos , Braquiterapia/efeitos adversos , Humanos , Imageamento por Ressonância Magnética , Masculino , Agulhas/efeitos adversos , Posicionamento do Paciente , Dosagem Radioterapêutica , Radioterapia Guiada por Imagem/efeitos adversos
4.
Phys Med Biol ; 60(19): 7567-83, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26378657

RESUMO

Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm(3)to 23.3 cm(3)) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.


Assuntos
Braquiterapia/instrumentação , Braquiterapia/normas , Agulhas/normas , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Automação , Fracionamento da Dose de Radiação , Humanos , Imageamento por Ressonância Magnética , Masculino
5.
Minerva Stomatol ; 64(1): 47-52, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25660592

RESUMO

The Doppler ultrasonography (DU) in cases of arteriovenous malformations (AVMs) is not widely use by dentists and there are a lack of information on the topic in the literature. AVM is common in the region of the head and neck and are commonly confused with hemangiomas (congenital). Appropriate classification is essential for therapeutic decision. The diferential diagnosis is based on clinical history, diascopy, and, if necessary, diagnostic imaging. This article present two cases of oral AVM in which DU was crucial in detecting a venous and/or arterial component in purplish lesions in the tongue and buccal mucosa, with positive diascopy. In our cases, after DU, we found a predominance of blood component within the lesion and therefore both patients were referred to the head and neck surgeon for surgical removal of the lesion. Only in the presence of a venous component does outpatient treatment become feasible. Given the predominance of the arterial component, outpatient procedures are contraindicated. Therefore DU is an important supplementary test, being of great importance in the clinical decision and treatment plan for oral AVMs and should become a routine part of the dentist front of vascular lesions of medium to large size.


Assuntos
Malformações Arteriovenosas/diagnóstico por imagem , Boca/irrigação sanguínea , Feminino , Humanos , Pessoa de Meia-Idade , Ultrassonografia
6.
Hum Exp Toxicol ; 30(9): 1275-81, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21071548

RESUMO

The purpose of the present study was to characterize the genetic damage induced by paradoxical sleep deprivation (PSD) in combination with cocaine or ecstasy (3,4-methylenedioxymethamphetamine; MDMA) in multiple organs of male mice using the single cell gel (comet) assay. C57BL/6J mice were submitted to PSD by the platform technique for 72 hours, followed by drug administration and evaluation of DNA damage in peripheral blood, liver and brain tissues. Cocaine was able to induce genetic damage in the blood, brain and liver cells of sleep-deprived mice at the majority of the doses evaluated. Ecstasy also induced increased DNA migration in peripheral blood cells for all concentrations tested. Analysis of damaged cells by the tail moment data suggests that ecstasy is a genotoxic chemical at the highest concentrations tested, inducing damage in liver or brain cells after sleep deprivation in mice. Taken together, our results suggest that cocaine and ecstasy/MDMA act as potent genotoxins in multiple organs of mice when associated with sleep loss.


Assuntos
Transtornos Relacionados ao Uso de Anfetaminas/genética , Encéfalo/efeitos dos fármacos , Transtornos Relacionados ao Uso de Cocaína/genética , Dano ao DNA , Fígado/efeitos dos fármacos , Privação do Sono/genética , Transtornos Relacionados ao Uso de Anfetaminas/sangue , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Transtornos Relacionados ao Uso de Cocaína/sangue , Transtornos Relacionados ao Uso de Cocaína/patologia , Ensaio Cometa , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Privação do Sono/sangue , Privação do Sono/patologia
7.
Eur J Gynaecol Oncol ; 27(3): 307-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16800268

RESUMO

INTRODUCTION: Abdominal scar recurrence of endometrial carcinoma after abdominal total hysterectomy is very rare. We report a case of a 65-year-old woman who had two recurrences in the abdominal incisional scar after total hysterectomy. CASE REPORT: A 65-year-old woman underwent total hysterectomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy because of well-differentiated endometrial adenocarcinoma (Stage IIB). Thus, the patient was treated by external beam radiotherapy. She developed two recurrences in the abdominal incisional scar two and three years after total hysterectomy, respectively. Surgery plus chemotherapy and surgery plus hormonal therapy were used for treatment of the first and second scar recurrence, respectively. CONCLUSIONS: It is a very intriguing and controversial biologic question how neoplastic cells can implant and grow in an abdominal scar without other concomitant metastases. We report a review of the literature and the possible mechanism of recurrences in laparotomy wounds.


Assuntos
Parede Abdominal , Adenocarcinoma/cirurgia , Cicatriz , Neoplasias do Endométrio/cirurgia , Laparotomia , Recidiva Local de Neoplasia , Inoculação de Neoplasia , Adenocarcinoma/patologia , Idoso , Cicatriz/etiologia , Cicatriz/patologia , Neoplasias do Endométrio/patologia , Feminino , Humanos , Histerectomia
8.
Behav Brain Res ; 170(2): 287-92, 2006 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-16621058

RESUMO

Ecstasy ((+/-)3,4-methylenedioxymethamphetamine, MDMA) is a psychostimulant and a synthetic derivative of amphetamine that, according to its consumers, promotes the enhancement of sexual pleasure. This study sought to investigate the effects of ecstasy in the genital reflexes of paradoxical sleep deprived (PSD) male rats. Distinct groups of PSD rats were administered with saline or different doses of ecstasy. The incidence of genital reflexes was verified for 100 min. The four doses that were used induced genital reflexes in PSD animals and these significantly differed from their respective treated control groups. Under the influence of two intermediary doses (2.5 and 5mg/kg), all animals displayed erection and ejaculation. The frequency of genital reflexes was also significantly greater than in relation to the PSD-saline group. The comparison between cocaine and ecstasy in PSD rats revealed that ecstasy induced more erections and ejaculations than cocaine. Thus, the present results showed a great enhancement of the genital reflexes of PSD rats that might have occurred due to serotoninergic alterations induced by this illicit substance when associated to sleep deprivation.


Assuntos
Inibidores da Captação Adrenérgica/farmacologia , Ejaculação/efeitos dos fármacos , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Ereção Peniana/efeitos dos fármacos , Privação do Sono/fisiopatologia , Sono REM , Análise de Variância , Animais , Cocaína/farmacologia , Inibidores da Captação de Dopamina/farmacologia , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Wistar
9.
J Biol Chem ; 276(15): 12153-61, 2001 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-11069911

RESUMO

The angiogenic molecule placenta growth factor (PlGF) is a member of the cysteine-knot family of growth factors. In this study, a mature isoform of the human PlGF protein, PlGF-1, was crystallized as a homodimer in the crystallographic asymmetric unit, and its crystal structure was elucidated at 2.0 A resolution. The overall structure of PlGF-1 is similar to that of vascular endothelial growth factor (VEGF) with which it shares 42% amino acid sequence identity. Based on structural and biochemical data, we have mapped several important residues on the PlGF-1 molecule that are involved in recognition of the fms-like tyrosine kinase receptor (Flt-1, also known as VEGFR-1). We propose a model for the association of PlGF-1 and Flt-1 domain 2 with precise shape complementarity, consider the relevance of this assembly for PlGF-1 signal transduction, and provide a structural basis for altered specificity of this molecule.


Assuntos
Neovascularização Fisiológica/fisiologia , Proteínas da Gravidez/química , Sequência de Aminoácidos , Cristalografia por Raios X , Fatores de Crescimento Endotelial/química , Fatores de Crescimento Endotelial/metabolismo , Feminino , Humanos , Ligação de Hidrogênio , Linfocinas/química , Linfocinas/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Fator de Crescimento Placentário , Proteínas da Gravidez/metabolismo , Proteínas da Gravidez/fisiologia , Conformação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular , Homologia de Sequência de Aminoácidos , Fator A de Crescimento do Endotélio Vascular , Receptor 1 de Fatores de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
10.
Farmaco ; 55(3): 165-7, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10919072

RESUMO

In this paper we review current knowledge on placenta growth factor (PIGF) and summarise our data on its recombinant production in bacteria and its activity. PIGF and vascular endothelial growth factor (VEGF) are both angiogenic factors belonging to the platelet-derived growth factor (PDGF) family. PIGF is a dimeric glycoprotein which shares a number of biochemical and functional features with VEGF. The aminoacidic similarity between the two factors is high (about 50%) in the PDGF-like domain. By alternative splicing of the PIGF mRNA, three forms of PIGF protein are generated which are named PIGF-1, PIGF-2 and PIGF-3. We have focused our attention on form 1 of human PIGF (PIGF-1). A large quantity of active recombinant PIGF-1 has been obtained using a bacterial expression system. By optimising the fermentation and purification it was possible to produce about 140 mg/l of culture of active PIGF-1, which is potentially suitable for a pharmaceutical use. The angiogenic activity of two different batches of bacteria-derived PIGF-1 obtained in our laboratory was demonstrated in chick chorionallantoic membrane assays. Finally, in preliminary studies we have shown that bacteria-derived PIGF-1 has a protective effect against myocardial lesions induced by isoprenaline in rat and rabbit.


Assuntos
Substâncias de Crescimento/biossíntese , Substâncias de Crescimento/farmacologia , Placenta/metabolismo , Proteínas da Gravidez/biossíntese , Proteínas da Gravidez/farmacologia , Animais , Bactérias/metabolismo , Cardiotônicos/antagonistas & inibidores , Cardiotônicos/toxicidade , Embrião de Galinha , Cromatografia por Troca Iônica , Substâncias de Crescimento/isolamento & purificação , Humanos , Isoproterenol/antagonistas & inibidores , Isoproterenol/toxicidade , Miocárdio/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Fator de Crescimento Placentário , Reação em Cadeia da Polimerase , Proteínas da Gravidez/isolamento & purificação , Coelhos , Ratos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia
11.
Lab Invest ; 76(4): 517-31, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9111514

RESUMO

The placental-derived growth factor (PIGF) is a dimeric glycoprotein showing a high degree of sequence similarity to the vascular endothelial growth factor. Alternative splicing of the PIGF primary transcript gives rise to two forms, named PIGF-1 and PIGF-2, which differ only in the insertion of a highly basic 21-amino acid stretch at the carboxyl end. The presence of the PIGF mRNA in thyroid, placenta, lung, and goiter has indicated the tissues where this factor functions. However, the role of PIGF in vascular development has not yet been clearly established. In the present study, we described the purification of PIGF-1 from overexpressing eukaryotic cells and then measured the angiogenic activity of the purified PIGF-1 in vivo in the rabbit cornea and the chick chorioallantoic membrane assays. In both in vivo assays, PIGF-1 induced a strong neovascularization process that was blocked by affinity-purified anti-PIGF-1 antibody. In the avascular cornea, PIGF-1 induced angiogenesis in a dose-dependent manner and seemed to be at least as effective (if not more effective) than vascular endothelial growth factor and basic fibroblast growth factor under the same conditions and at the same concentration. PIGF-1 was shown to induce cell growth and migration of endothelial cells from bovine coronary postcapillary venules and from human umbilical veins. In these two in vitro assays, PIGF-1 seemed to have a comparable effect to that of vascular endothelial growth factor and basic fibroblast growth factor on the cultured microvascular endothelium (eg, capillary venule endothelial cells). In summary, this is the first study to demonstrate that PIGF-1 can induce angiogenesis in vivo and stimulate the migration and proliferation of endothelial cells in vitro.


Assuntos
Indutores da Angiogênese/farmacologia , Divisão Celular/efeitos dos fármacos , Fatores Quimiotáticos/farmacologia , Quimiotaxia/efeitos dos fármacos , Substâncias de Crescimento/farmacologia , Neovascularização Patológica/induzido quimicamente , Proteínas da Gravidez/farmacologia , Alantoide/irrigação sanguínea , Alantoide/efeitos dos fármacos , Alantoide/patologia , Indutores da Angiogênese/genética , Indutores da Angiogênese/isolamento & purificação , Animais , Bovinos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Fatores Quimiotáticos/genética , Fatores Quimiotáticos/isolamento & purificação , Embrião de Galinha , Córnea/irrigação sanguínea , Córnea/efeitos dos fármacos , Córnea/patologia , Relação Dose-Resposta a Droga , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Substâncias de Crescimento/genética , Substâncias de Crescimento/isolamento & purificação , Humanos , Neovascularização Patológica/patologia , Fator de Crescimento Placentário , Proteínas da Gravidez/genética , Proteínas da Gravidez/isolamento & purificação , Coelhos , Proteínas Recombinantes
12.
J Psychosom Res ; 37(6): 621-36, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8410748

RESUMO

One-hundred and twelve cadets attending the 141st training course for reserve officers of the 'Scuola Transmission' of the Italian Army were administered, 10 days after incorporation, a battery of personality tests and measures of stressful events in the preceding year. Test scores were considered both individually and grouped into factors. During the 6 months of the course all disease episodes for each cadet were recorded. Total episodes infections and traumas were considered. A significantly higher number of total episodes and, specifically, of infections was present in subjects reporting a higher number of stressful events, in interaction with attitudes towards parent figures, hardiness, loneliness, and an alienation factor. A younger age of subjects also appeared predictive of a higher number of total episodes and infections, as a main effect and in interaction with attitudes to mother, hardiness, and alienation. Very few effects were obtained for traumas, suggesting that the effects of variables are mediated through a biological route rather than through behaviour, as would be the case if traumas were involved. No effect was shown by measures of stressful events alone. Results are discussed in the light of a reconsideration of the notion of stressful events.


Assuntos
Suscetibilidade a Doenças/psicologia , Militares/psicologia , Adaptação Psicológica , Fatores Etários , Análise de Variância , Humanos , Incidência , Itália , Acontecimentos que Mudam a Vida , Estudos Longitudinais , Masculino , Personalidade , Testes Psicológicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...