Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Appl Radiat Isot ; 197: 110798, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37028101

RESUMO

Radio Pharmaceutical Therapy (RPT) comes forth as a promising technique to treat a wide range of tumors while ensuring low collateral damage to nearby healthy tissues. This kind of cancer therapy exploits the radiation following the decay of a specific radionuclide to deliver a lethal dose to tumor tissues. In the framework of the ISOLPHARM project of INFN, 111Ag was recently proposed as a promising core of a therapeutic radiopharmaceutical. In this paper, the production of 111Ag via neutron activation of 110Pd-enriched samples inside a TRIGA Mark II nuclear research reactor is studied. The radioisotope production is modeled using two different Monte Carlo codes (MCNPX and PHITS) and a stand-alone inventory calculation code FISPACT-II, with different cross section data libraries. The whole process is simulated starting from an MCNP6-based reactor model producing the neutron spectrum and flux in the selected irradiation facility. Moreover, a cost-effective, robust and easy-to-use spectroscopic system, based on a Lanthanum Bromo-Chloride (LBC) inorganic scintillator, is designed and characterized, with the aim of using it, in the future, for the quality control of the ISOLPHARM irradiated targets at the SPES facility of the Legnaro National Laboratories of INFN. natPd and 110Pd-enriched samples are irradiated in the reactor main irradiation facility and spectroscopically characterized using the LBC-based setup and a multiple-fit analysis procedure. Experimental results are compared with theoretical predictions of the developed models, showing that inaccuracies in the available cross section libraries prevent an accurate reproduction of the generated radioisotope activities. Nevertheless, models are normalized to our experimental data allowing for a reliable planning of the 111Ag production in a TRIGA Mark II reactor.


Assuntos
Radioisótopos , Compostos Radiofarmacêuticos , Relação Dose-Resposta à Radiação , Compostos Radiofarmacêuticos/uso terapêutico , Reatores Nucleares
2.
Rev Sci Instrum ; 93(8): 083001, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050098

RESUMO

The Selective Production of Exotic Species project is under construction at Laboratori Nazionali di Legnaro-INFN. The aim of the collaboration is to produce highly pure Radioactive Ion Beams (RIBs) from fission fragments of a uranium carbide (UCx) target activated by a cyclotron proton beam. In order to select a specific atomic species, the main tool to be applied is the resonant laser ionization technique. We have just completed the installation of a dedicated all solid state laser system whose elements are tunable to transitions of all the elements/isotopes of interest for the project. The new laser system is based on three Titanium:sapphire laser sources, independently pumped by three Nd:YLF pump lasers, and it can be coupled to two high harmonic generation (second harmonic generation, third harmonic generation, and fourth harmonic generation) setups. The power, wavelength, and position of the laser beams are continuously monitored and stabilized by using automated active systems to improve the beam production stability of RIBs. This paper presents the main features of the laser system and examples of application of a laser ion source, including a first demonstration of photoionization of stable silver, one of the most requested elements for RIB application.

3.
Rev Sci Instrum ; 92(5): 053304, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243328

RESUMO

The Isotope Separation On-Line (ISOL) technique is today established as one of the primary methods to produce high-intensity and high-quality radioactive beams. This technique produces, for a given amount of the desired isotope, many orders of magnitude of other radioactive species. Due to the activation generated by interactions of the primary beam, intense neutron fields, and deposition of the produced radioactive ions inside beam line elements, an ISOL facility in operation becomes an intense radioactive source. Therefore, the biological hazard imposes severe radiological safety challenges to the design, operation, maintenance, and final decommissioning of such facilities. A challenging component is the ion source complex, where the ion extraction electrode provides the extraction of radioactive ions from the ion source and the first acceleration to the extracted beam. The radioactive contamination of this sub-component is studied, by means of the FLUKA code, in the case of the Selective Production of Exotic Species facility, which is in the advanced construction phase at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Padua, Italy. The developed model includes isotope production by the interactions of a 40 MeV energy proton beam on a 238UCx target, selection of radioactive isotopes that are able to stick on the electrode tip, time evolution of the deposited isotopes during the operation and cooling periods before maintenance interventions, and evaluation of the ambient dose equivalent rate generated by the contamination of the electrode tip. Based on these results, the possibility of manual interventions for maintenance and emergency vs the use of remote handling systems is discussed.

4.
Appl Radiat Isot ; 175: 109795, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34087532

RESUMO

Accelerator-based techniques with electromagnetic mass separation are considered among the most innovative and promising strategies to produce non-conventional radionuclides for nuclear medicine. Such approach was successfully used at CERN, where the dedicated MEDICIS facility was built, and at TRIUMF, where the ISAC radioactive beam facility was used to produce unconventional α-emitters. In such framework, the Legnaro National Laboratories of the Italian Institute of Nuclear Physics (INFN-LNL) proposed the ISOLPHARM project (ISOL technique for radioPHARMaceuticals), which will exploit radionuclides producible with the SPES (Selective Production of Exotic Species) ISOL (Isotope Separation On-Line) facility to develop novel radiopharmaceuticals. The ISOL technique utilizes the irradiation with a primary beam of particles/nuclei of a production target where radionuclides are produced. A radioactive ion beam is subsequently extracted from the production target unit, and transported up to an analyzing magnet, where non-isobaric contaminants are filtered out. The so-obtained purified radioactive beam is dumped onto an implantation substrate, referred as collection target. Then, the desired nuclides can be chemically harvested from the collected isobars, and the isotopically pure atom collection can be employed to radiolabel high specific activity radiopharmaceuticals. Metallic deposition targets in the form of coated metal foils were mostly used at TRIUMF and CERN. At ISOLPHARM, a different approach is under investigation which foresees the use of soluble cold-pressed collection targets, possibly facilitating the chemical purification process of the collected radionuclides. In this study, the production and characterization of some of the ISOLPHARM collection targets is presented, in particular, soluble salts (NaCl and NaNO3) and organic materials widely used for pharmaceutical tablets production are considered. All such materials proved to be potentially suitable as collection targets, since solid samples were easily produced and resulted compatible with the vacuum conditions required for the ion implantation process. Furthermore, some of the selected substrates were used for proof-of-concept deposition tests with stable silver, to prove their suitability as ISOLPHARM deposition substrates for silver-111, a promising candidate for radiotherapy. Such tests highlighted possible scenarios useful for the development of new alternative materials, as the use of insoluble organic targets.


Assuntos
Radioisótopos/química , Medicina Nuclear/métodos , Radioisótopos/isolamento & purificação , Cintilografia
5.
J Clin Endocrinol Metab ; 99(8): 2861-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24823456

RESUMO

CONTEXT: Insufficient sleep is associated with increased cardiometabolic risk. Alterations in hypothalamic-pituitary-adrenal axis may underlie this link. OBJECTIVE: Our objective was to examine the impact of restricted sleep on daytime profiles of ACTH and cortisol concentrations. METHODS: Thirteen subjects participated in 2 laboratory sessions (2 nights of 10 hours in bed versus 2 nights of 4 hours in bed) in a randomized crossover design. Sleep was polygraphically recorded. After the second night of each session, blood was sampled at 20-minute intervals from 9:00 am to midnight to measure ACTH and total cortisol. Saliva was collected every 20 minutes from 2:00 pm to midnight to measure free cortisol. Perceived stress, hunger, and appetite were assessed at hourly intervals by validated scales. RESULTS: Sleep restriction was associated with a 19% increase in overall ACTH levels (P < .03) that was correlated with the individual amount of sleep loss (rSp = 0.63, P < .02). Overall total cortisol levels were also elevated (+21%; P = .10). Pulse frequency was unchanged for both ACTH and cortisol. Morning levels of ACTH were higher after sleep restriction (P < .04) without concomitant elevation of cortisol. In contrast, evening ACTH levels were unchanged while total and free cortisol increased by, respectively, 30% (P < .03) and 200% (P < .04). Thus, the amplitude of the circadian cortisol decline was dampened by sleep restriction (-21%; P < .05). Sleep restriction was not associated with higher perceived stress but resulted in an increase in appetite that was correlated with the increase in total cortisol. CONCLUSION: The impact of sleep loss on hypothalamic-pituitary-adrenal activity is dependent on time of day. Insufficient sleep dampens the circadian rhythm of cortisol, a major internal synchronizer of central and peripheral clocks.


Assuntos
Sistema Hipotálamo-Hipofisário/fisiopatologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Privação do Sono/fisiopatologia , Hormônio Adrenocorticotrópico/sangue , Adulto , Ritmo Circadiano , Estudos Cross-Over , Saúde , Humanos , Hidrocortisona/sangue , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Sistema Hipófise-Suprarrenal/metabolismo , Sono/fisiologia , Privação do Sono/metabolismo , Fatores de Tempo , Adulto Jovem
6.
Neoplasma ; 60(3): 302-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23374000

RESUMO

Electronic portal imaging (EPI) is commonly used to identify and correct for inter-fraction variability in tangential breast irradiation. Based on the institutional policy, EPI registration is performed by either radiation oncologist or therapist. Little data is available on the inter-observer agreement in EPI registration among different health practitioners. The aim of our study was to analyze inter-observer agreement among radiation oncologists and therapists in the evaluation of EPI for breast cancer radiotherapy verification. EPI data of 40 patients treated with tangential fields were independently reviewed by a radiation oncologist (on-line, just before treatment) and off-line by junior and senior therapists. Displacement of each EPI image with respect to the digital reconstructed radiographs (DRRs) was quantified using manual EPI registration based on bony marks with the corresponding DRRs. Agreement between observers was evaluated using weighted Cohen's Kappa statistics. In 95% out of 720 EPI-DRR comparisons, the EPI-DRR misalignment was < 5 mm. The difference between observers was < 2 mm in 666 (92.5%) out of all 720 delta values. High inter-observer agreement was found, with weighted Cohen's Kappa values attesting evaluation overlaps ranging from moderate (among therapists) to almost perfect (among radiation oncologist and therapists). The high agreement among the observers demonstrated the precision of breast localization using EPI. These findings suggest that routine EPI-based patient set-up verification in breast cancer radiotherapy can be safely entrusted to trained therapists (supervision should be assured based on the local tasks definition). Our study might be useful in quality assurance and in the optimization of workload in the radiotherapy departments. They might allow for wider implementation of complex and evolving radiotherapy technologies.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/radioterapia , Diagnóstico por Imagem , Eletrônica , Variações Dependentes do Observador , Padrões de Prática Médica , Planejamento da Radioterapia Assistida por Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Feminino , Clínicos Gerais , Humanos , Pessoa de Meia-Idade , Prognóstico , Radioterapia (Especialidade) , Intensificação de Imagem Radiográfica
7.
Anal Bioanal Chem ; 395(7): 1977-85, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19760192

RESUMO

In favourable conditions of low temperature and low oxygen concentration, archaeological waterlogged wooden artefacts, such as shipwrecks, can survive with a good state of preservation. Nevertheless, anaerobic bacteria can considerably degrade waterlogged wooden objects with a significant loss in polysaccharidic components. Due to these decay processes, wood porosity and water content increase under ageing. In such conditions, the conservation treatments of archaeological wooden artefacts often involve the replacement of water with substances which fill the cavities and help to prevent collapse and stress during drying. The treatments are very often expensive and technically difficult, and their effectiveness very much depends on the chemical and physical characteristics of the substances used for impregnation. Also important are the degree of cavity-filling, penetration depth and distribution in the structure of the wood. In this study, the distribution in wood cavities of some mixtures based on polyethylene glycols and colophony, used for the conservation of waterlogged archaeological wood, was investigated using synchrotron radiation X-ray computed microtomography (SR-microCT). This non-destructive imaging technique was useful for the study of the degraded waterlogged wood and enabled us to visualise the morphology of the wood and the distribution of the materials used in the wood treatments. The study has shown how deposition is strictly related to the dimension of the wooden cavities. The work is currently proceeding with the comparison of synchrotron observations with the data of the solutions viscosity and with those of the properties imparted to the wood by the treatments.


Assuntos
Arqueologia/métodos , Tomografia com Microscopia Eletrônica/métodos , Síncrotrons , Água , Madeira/química , Tomografia com Microscopia Eletrônica/instrumentação , História Antiga , Madeira/história
8.
J Endocrinol Invest ; 32(9): 773-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19636221

RESUMO

BACKGROUND AND AIM: The management of pituitary adenomas secreting TSH has evolved considerably over the last decades.We report the clinical features, management, and outcome of a large monocentric series. MATERIAL AND METHODS: A monocentric retrospective cohort of 26 patients admitted to our Department of Endocrinology between 1983 and 2007, followed for a period up to 204 months. The diagnosis of TSH-secreting adenoma was based on clinical and biochemical findings of central hyperthyroidism. Evaluation of basal and dynamic pituitary function, magnetic resonance imaging or computerized tomography scan were performed in all patients. Twenty-two patients, of whom 15 pre-treated by somatostatin analogs (SSA), underwent trans-sphenoidal surgery and were regularly re-evaluated. RESULTS: The number of cases increased over the years. Age at diagnosis, micro- to macroadenoma ratio, and mean estimated latency between first symptoms and diagnosis did not appreciably change over time. Latency was significantly shorter in macroadenomas. Following surgery, 55% of patients obtained remission (success rate of 40 and 67% in macro- and microadenomas, respectively). SSA pre-treatment led to an apparent although not statistically- significant increase in success rate in micro- but not in macroadenomas. CONCLUSIONS: In a monocentric group of 26 TSH-secreting adenomas the high ratio between micro- and macroadenomas remained stable over time with a significantly shorter diagnosis latency in macroadenomas. A more precocious recognition of the tumors and possibly the use of presurgical SSA allowed a high remission rate. A varied combination of neurosurgery, SSA, radiotherapy, and thyroid ablation led to the control of the disease in all the patients studied.


Assuntos
Adenoma/diagnóstico , Neoplasias Hipofisárias/diagnóstico , Tireotropina/metabolismo , Adenoma/tratamento farmacológico , Adenoma/cirurgia , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Hipertireoidismo/diagnóstico , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes de Função Hipofisária , Neoplasias Hipofisárias/tratamento farmacológico , Neoplasias Hipofisárias/cirurgia , Estudos Retrospectivos , Somatostatina/análogos & derivados , Somatostatina/uso terapêutico , Tomografia Computadorizada por Raios X
9.
Sci Total Environ ; 407(7): 2383-9, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19157513

RESUMO

Bird droppings are often quoted as a decay agent for outdoor goods, in particular buildings and statues. Undoubtedly, they represent one of the major causes of aesthetic damage on outdoor materials, but the real chemical damage they are able to induce, in particular on metals, is not so well studied. This work focused on the short term role of uric acid, the main constituent of bird urine, with respect to copper, which make such an important contribution to architectural elements of buildings and outdoor sculpture. Preliminary results of laboratory tests and analyses on real exposed samples showed that uric acid chemically affects copper and bronzes: the surface of the metal is modified and copper urates formed. Also natural patina, formed on statues and roof, react with uric acid, even if it seems to afford some protection toward bird droppings. In general, experimental results confirm that the potential chemical damage by bird droppings is significant when considering external cultural heritage such as statues, metal monuments and buildings with historic copper roofs.


Assuntos
Aves , Cobre/química , Escultura , Ácido Úrico/química , Animais , Materiais de Construção , Corrosão , Urina/química
10.
J Endocrinol Invest ; 31(9 Suppl): 39-43, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19020384

RESUMO

Neurodegenerative diseases are a major focus of scientific and clinical interest because of their increasing medical and social importance. Due to the intimate connections between central nervous and endocrine systems, it is reasonable to suspect that important, and in some cases clinically relevant, endocrine modifications may accompany the progression of neurodegenerative diseases. Data on endocrine modifications in different neurodegenerative diseases have been reported, but results have often been non-conclusive, or conflicting. Accumulating evidence suggests that the GH/IGF-I axis is involved in the regulation of brain growth, development, and metabolism and in the regulation of muscle function. Dysfunctions in GH/IGF-I axis in most of neurodegenerative diseases are therefore reviewed. Alterations of this system could be actors in the complex network leading to (at least some) neurodegenerative diseases. A thorough effort in investigating every possible involvement is warranted, in the light of future therapeutic strategies.


Assuntos
Hipopituitarismo/complicações , Doenças Neurodegenerativas/etiologia , Esclerose Lateral Amiotrófica/sangue , Esclerose Lateral Amiotrófica/etiologia , Esclerose Lateral Amiotrófica/metabolismo , Cognição/fisiologia , Hormônio do Crescimento Humano/sangue , Hormônio do Crescimento Humano/metabolismo , Humanos , Hipopituitarismo/sangue , Hipopituitarismo/metabolismo , Hipopituitarismo/fisiopatologia , Fator de Crescimento Insulin-Like I/metabolismo , Músculos/fisiopatologia , Doenças Neurodegenerativas/sangue , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/fisiopatologia
11.
Clin Endocrinol (Oxf) ; 69(2): 197-201, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18221398

RESUMO

BACKGROUND: Impaired GH secretion is a common finding in patients with primary hyperparathyroidism (PHP). Ghrelin displays strong GH-releasing action, mainly at the hypothalamic level. OBJECTIVE: To evaluate secretory response of GH to ghrelin in PHP patients. PATIENTS: Fifteen patients [11 women/4 men, mean age 54 years, range 32-70 years, body mass index (BMI) 25.0 +/- 0.7 kg/m(2)] affected with PHP due to single parathyroid adenoma and 35 normal age-matched subjects (23 women/12 men, mean age 58 years, range 35-68 years, BMI 24.1 +/- 1.1 kg/m(2)). METHODS: A measure of 1 microg/kg body weight i.v. acylated ghrelin or 1 microg/kg body weight i.v. GH releasing hormone (GHRH) followed by 0.5 g/kg body weight i.v. arginine (ARG) hydrochloride were administered to all subjects on alternate days in order to evaluate GH response. RESULTS: Mean serum GH peak after GHRH + ARG was 32.6 +/- 7.8 and 17.4 +/- 4.0 microg/l, in controls and PHP patients, respectively (P < 0.05). Mean serum GH peak after ghrelin was 70.4 +/- 31.5 and 16.8 +/- 1.9 microg/l, in controls and PHP patients, respectively, (P < 0.001). Using ROC curves, a serum GH peak > 22 microg/l after ghrelin stimulation might be considered as a cut-off value for identifying normal subjects. Ten (67%) PHP patients have impaired GH response to GHRH + ARG and 13 (87%) to ghrelin. Serum GH peak after ghrelin or GHRH + ARG was unrelated to serum IGF-1, PTH or ionized calcium concentrations. CONCLUSIONS: The present data confirm that GH secretion is impaired in PHP patients using the potent GH secretagogue ghrelin and suggest that impaired GH secretion is likely due to a deleterious effect of hypercalcaemia at the hypothalamic level in PHP patients.


Assuntos
Grelina/farmacologia , Hormônio do Crescimento Humano/metabolismo , Hiperparatireoidismo Primário/metabolismo , Acilação , Adenoma/sangue , Adenoma/complicações , Adenoma/metabolismo , Adulto , Idoso , Técnicas de Diagnóstico Endócrino , Feminino , Grelina/administração & dosagem , Hormônio do Crescimento Humano/sangue , Humanos , Hiperparatireoidismo Primário/sangue , Hiperparatireoidismo Primário/etiologia , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Neoplasias das Paratireoides/sangue , Neoplasias das Paratireoides/complicações , Neoplasias das Paratireoides/metabolismo , Via Secretória/efeitos dos fármacos , Sensibilidade e Especificidade
12.
J Hazard Mater ; 153(3): 1270-4, 2008 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-17980961

RESUMO

Bottom and fly ashes coming from the urban wastes incineration represent a by-product nowadays landfilled. By mixing different amount of these residues with others inert materials, such as glass cullet and feldspar waste, two vitrifiable mixtures are tailored. Glasses, obtained by means of vitrification process, are chemically stable with low leachability of contaminants and show comparable properties to those of commercial soda-lime glasses. Moreover, from the thermal and mechanical characterisation the tendency of these glasses to crystallise, for their transformation into glass-ceramic materials, has been evidenced.


Assuntos
Carbono , Vidro , Incineração , Resíduos Industriais , Material Particulado , Eliminação de Resíduos/métodos , Cerâmica , Cinza de Carvão , Conservação dos Recursos Naturais , Metais/análise , Microscopia Eletrônica de Varredura
13.
J Endocrinol Invest ; 30(9): 767-70, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17993769

RESUMO

Amyotrophic lateral sclerosis (ALS), the most common motor neurone disorder in human adults, is characterized by selective and progressive degeneration of upper and lower motor neurones in the central nervous system. The main currently available drug for ALS treatment is riluzole, a compound that acts through inhibition of glutamate release, postsynaptic receptor activation, and voltage-sensitive channel inhibition. GH secretion, evaluated by GHRH+arginine (ARG) test, has recently been reported to be impaired in most untreated ALS patients. The aim of the present study was to evaluate whether riluzole administration could interfere with GH secretion and therefore with the diagnosis of adult GH deficiency. Ten patients (6 males, 4 females, mean age 59+/-11 yr) were studied performing GHRH+ARG test before and 3 months after starting riluzole treatment (100 mg/day). Blood samples for GH were collected at baseline, at 30 and 60 min. Both before and during riluzole treatment, 5 patients showed GH deficiency and 5 patients had a normal GH response according to body mass index (BMI). Mean peak GH levels were similar before and during riluzole treatment (13.4+/-10 vs 14.2+/-10.1 microg/l, p=ns). No significant correlation was observed between GH concentrations and age, BMI, disease duration, severity or clinical (bulbar/spinal) form. In conclusion, the present data confirm that GH secretion is impaired in a new series of ALS patients and indicate that riluzole treatment does not interfere with GH secretion. Thus, evaluation of GH secretion in ALS patients can also be performed without withdrawing riluzole treatment.


Assuntos
Esclerose Lateral Amiotrófica/sangue , Esclerose Lateral Amiotrófica/tratamento farmacológico , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Hormônio do Crescimento/metabolismo , Riluzol/uso terapêutico , Idoso , Índice de Massa Corporal , Feminino , Hormônio do Crescimento/sangue , Hormônio do Crescimento/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Fatores de Tempo
14.
Clin Endocrinol (Oxf) ; 65(3): 385-8, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16918961

RESUMO

OBJECTIVE: ALS is the most common motor neurone disorder in human adults. Scanty data on endocrine abnormalities have been reported. The aim of the present study was to investigate the GH-IGF-I axis in ALS patients. PATIENTS: Twenty-two ALS patients (12 men, 10 women), mean age 61 years, and 25 normal age- and sex-matched subjects. No patient was under riluzole therapy. MEASUREMENTS: Patients and controls underwent a GHRH plus arginine test. IGF-I was determined at baseline. A complete evaluation of pituitary function was also performed. RESULTS: Mean (+/- SD) basal GH levels were significantly reduced compared with normal controls (0.2 +/- 0.3 vs 1.6 +/- 1.8 ng/ml, P < 0.01), as well as peak GH concentrations after GHRH + arginine administration (12.6 +/- 8.9 vs 39.9 +/- 18.7 ng/ml, P < 0.001). Six (27%) patients showed a normal GH response to stimulus; 7 (32%) patients displayed a moderate GH deficiency; in 9 (40%) patients GH response was markedly deficient. IGF-I levels were normal in the majority of patients (mean +/- SD: 143.6 +/- 63.8 ng/ml). No significant correlation was observed between peak GH concentrations and age, BMI, disease duration, severity or clinical form. A higher incidence of GH deficiency was observed in male compared to female patients (83%vs 60%), with a peak GH response in males significantly lower than in females (8.9 +/- 6.6 vs 17 +/- 9.6 ng/ml, P = 0.03). Eighteen patients repeated the test after 5 months and similar results were obtained. CONCLUSIONS: The present data indicate a reduction of GH secretion in ALS patients.


Assuntos
Esclerose Lateral Amiotrófica/fisiopatologia , Hormônio do Crescimento/metabolismo , Idoso , Arginina , Estudos de Casos e Controles , Feminino , Hormônio Liberador de Hormônio do Crescimento , Humanos , Fator de Crescimento Insulin-Like I/análise , Masculino , Pessoa de Meia-Idade , Fatores Sexuais
15.
J Endocrinol Invest ; 28(9): 819-21, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16370562

RESUMO

PTH-related peptide (PTHrP), a member of the PTH family, is widely expressed in foetal and adult tissues, and it has been found in benign and malignant tumors, including GH and PRL-secreting adenomas. Conflicting data are reported in literature on serum PTHrP concentrations in patients with Cushing's disease. The aim of the present study was to further evaluate peripheral and inferior petrosal sinus (IPS) serum PTHrP concentrations before and after CRH, in a group of consecutive patients with ACTH-dependent Cushing's disease. Nine patients with active ACTH-dependent Cushing's disease (8 women and 1 man, age +/- SD 41 +/- 13 yr) were submitted to peripheral and IPS sampling under fluoroscopic control before and after iv administration of CRH. All patients were subsequently submitted to transsphenoidal surgery and an ACTH-secreting microadenoma was found in all cases. In all patients, serum IPS and peripheral ACTH measurement were in keeping with the diagnosis of ACTH-dependent Cushing's disease. Serum PTHrP concentrations before and after CRH stimulation were below the sensitivity limit of the assay in all samples, and no gradient between IPS and peripheral sampling was observed. Our data, combined with others reported in literature, indicate that PTHrP release by ACTH-secreting tumors is not a common occurrence. Therefore, we conclude that IPS and peripheral PTHrP are of little clinical usefulness.


Assuntos
Hormônio Adrenocorticotrópico/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/sangue , Amostragem do Seio Petroso/métodos , Hipersecreção Hipofisária de ACTH/sangue , Adulto , Idoso , Cálcio/sangue , Hormônio Liberador da Corticotropina/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hipersecreção Hipofisária de ACTH/tratamento farmacológico , Hipersecreção Hipofisária de ACTH/metabolismo
16.
J Endocrinol Invest ; 28(4): 346-9, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15966508

RESUMO

Cystatin C (Cys C) is a cysteine protease inhibitor produced at a constant rate by nucleated cells, filtered through the glomerular membrane and reabsorbed by kidney tubular cells. Aim of this cross-sectional and longitudinal study was to assess serum Cys C and creatinine (Crea) concentrations in thyroid dysfunction. One hundred and eighty-one patients, 26 with untreated non-toxic nodular goiter, 58 with hyperthyroidism, 31 on L-T4 suppressive therapy for non-toxic nodular goiter, 35 with short-term hypothyroidism after L-T4 withdrawal to perform whole body scan for thyroid cancer, 11 with long-term hypothyroidism due to chronic autoimmune thyroiditis and 20 patients with mild hypothyroidism were enrolled in the study. Fifty-seven age- and sex-matched normal subjects served as controls. Serum Cys C, Crea, free T4 (FT4), FT3 and TSH were assessed. Thirty hyperthyroid patients and 35 short-term hypothyroid patients were followed prospectively until euthyroidism was reached by methimazole or L-T4 therapy. The cross-sectional study showed that mean serum Crea concentrations were significantly reduced in overt hyperthyroid or subclinical hyperthyroid patients, while it was increased in overt hypothyroid patients, but not in mild hypothyroidism. Conversely, serum Cys C levels were significantly increased in overt hyperthyroid patients compared to controls (p<0.05), and significantly decreased in short-term, long-term and mild hypothyroids (p<0.05, p<0.05, p<0.01, respectively). However, 36 (62%) hyperthyroid patients and 50 (76%) hypothyroid patients had normal serum Cys C values. In the prospective study, restoration of euthyroidism by either methimazole or L-T4 therapy was associated with normalization of mean serum Cys C concentrations. In conclusion, thyroid dysfunction affects serum Cys C concentration, possibly influencing the production rate of the protein. However, the observation that hyper- or hypothyroid patients have normal serum Cys C levels limits its use as a marker of peripheral thyroid hormone effect.


Assuntos
Creatinina/sangue , Cistatinas/sangue , Doenças da Glândula Tireoide/complicações , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Estudos Transversais , Cistatina C , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade
17.
Waste Manag ; 25(2): 191-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15737717

RESUMO

The identification of significant pollutants emitted from the contamination source is the first step in evaluating the impact associated with anthropic activity. Municipal solid waste (MSW) incinerators are still generally perceived as great pollutant sources, in particular due to their gaseous emissions from the stack, which constitute the major effluent from the plant. In this work a life cycle assessment and an integrated environmental monitoring system were applied together, in order to obtain complete information about the incineration process and its environmental impact. The former is a proven methodology, but its application to waste management systems constitutes a relatively new field of application with a great developmental potential. The contribution of the incineration process to the different environmental impact categories was investigated, finding many avoided impacts due to energy recovery. The latter is an innovative approach that allows a remarkable understanding of impact due to a contamination source; interesting correlations were found between heavy metals both in gas emissions and in natural matrices in the surroundings.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Incineração , Modelos Teóricos , Coleta de Dados
18.
J Endocrinol Invest ; 27(7): 643-7, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15505987

RESUMO

Prostate-specific antigen (PSA) is a serine proteases produced by prostatic epithelial cells detectable in male serum and seminal plasma. PSA is also expressed in some female tissues and fluids and is increased in hirsute women showing a positive correlation with androgens. Accordingly, it has been suggested that PSA might be a marker of androgen action in women. The aim of this observational study was to assess serum PSA concentration in acro megalic women with active disease, in remission or during somatostatin analogs therapy. Forty-four acromegalic women, 15 with active disease, 10 in remission and 19 under long-acting somatostatin analogs therapy were enrolled in the study; 273 normal women matched for age, body mass index, with no signs of hirsutism, served as controls. Serum PSA, 3a-androstanediol (3alpha-AG), total testosterone (T), DHEAS, LH, FSH and estradiol were assessed. No patient or control had been given estrogen or antiandrogen drugs; no acromegalic women had hyperprolactinemia or hypopituitarism. Serum PSA concentration was significantly higher in acromegalic patients than in control subjects (p < 0.0001). Patients with active acromegaly or under somatostatin analogs therapy had significant higher serum PSA concentration than controls, while patients in remission after adenomectomy did not differ. Serum PSA was detectable in serum of 75% acromegalic women and 45% of controls. In addition 24% of acromegalic women had serum PSA concentrations higher than the mean +/- 2SD of control subjects. Differences in serum PSA levels did not reach statistical significance in the different acromegalic subgroups possibly because of the small number of subjects, but patients with active acromegaly had higher serum PSA levels than patients under somatostatin analogs therapy or in remission. Acromegalic women had significantly higher serum PSA concentrations than controls both before and after menopause (p < 0.01). 3alpha-AG (p < 0.05) and T (p < 0.01) were higher in acromegalic than in control subjects in pre-menopause (PM) but not in post-menopause (M). A correlation was found in the whole group of acromegalic patients between serum PSA and 3a-AG concentrations (r = 0.3, p < 0.01). In conclusion, acromegalic is associated with an increase in serum PSA concentrations as a group, although this increase is observed, at an individual level, in only 24% of cases. Patients whose disease is controlled by somatostatin analogs or has been cured by pituitary adenomectomy tend to have lower serum PSA levels than patients with active disease. M patients tend to have lower PSA values than PM women, consistent with the main androgen control of PSA production. However, the observation that M women still have higher serum PSA levels than controls suggest that in acromegaly PSA is regulated not only by androgens but also by the GH/IGF-I system itself.


Assuntos
Acromegalia/complicações , Acromegalia/patologia , Biomarcadores/análise , Antígeno Prostático Específico/sangue , Acromegalia/tratamento farmacológico , Adulto , Fatores Etários , Idoso , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Somatostatina/análogos & derivados , Somatostatina/uso terapêutico
19.
Chemosphere ; 55(3): 455-66, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14987944

RESUMO

Wet and dry atmospheric depositions and soil chemical and microbiological properties were determined in a Mediterranean natural ecosystem of Central Italy near Rome (Castelporziano Estate). The monitoring of depositions permitted us to quantify the exceedances of S and N compounds (expressed as eqH(+)ha(-1)year(-1)) over the critical loads of acidity. Critical loads, i.e. the quantity of a substance which a part of the environment can tolerate without adverse effects occurring, were determined adopting the level 0 methodology following the UN/ECE Convention on Long-range Transboundary Air Pollution. Deposition data were available for the period 1992-1997, and acidity exceedances were referred to the main vegetation types present in the area. Results showed that most part of the Estate has a medium degree of vulnerability to acidification, and the corresponding risk of acidification deriving from the exceedances of atmospheric deposition was rather low. The study of soil chemical and microbiological properties included mainly total soil organic carbon (SOC), microbial biomass-C, biomass-C/SOC, soil respiration, and metabolic quotient (qCO2). Soil organic C metabolism has been discussed on the basis of the results from eight sampling sites.


Assuntos
Monitoramento Ambiental , Microbiologia do Solo , Solo/análise , Poluentes Atmosféricos/análise , Biomassa , Carbono/análise , Concentração de Íons de Hidrogênio , Itália , Compostos de Nitrogênio/análise , Compostos de Sódio/análise
20.
Chemosphere ; 51(5): 357-68, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12598001

RESUMO

Odorous compounds from a landfill have been characterised by gas-chromatography-mass-spectrometry, identifying about 100 volatile organic compounds. Air samples from different landfill sites and from the environment have been analysed after a solid-phase microextraction on a three-phase fiber, DVB/Carboxen/PDMS, which allowed a preconcentration and the chromatographic data obtained from the most significant emission sources have been submitted to chemometric analysis in order to better establish specific markers of olfactory pollution. For example limonene was a typical tracer of fresh wastes, while p-cymene was characteristic of leachate and biogas. By the developed analytical procedure it has been evaluated the efficiency of a scrubber plant utilised in the landfill in order to remove malodour compounds. The average removal efficiency was not very high (about 23.5%) due to scarce ability in removing low polarity compounds. Furthermore, it has been demonstrated the suitability of a microgas chromatograph for the continuous on-site monitoring of air pollution in order to rapidly individuate emission sources of olfactive nuisances.


Assuntos
Poluentes Atmosféricos/análise , Odorantes/análise , Eliminação de Resíduos , Físico-Química/métodos , Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Miniaturização/métodos , Compostos Orgânicos/análise , Volatilização
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA