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1.
Phys Rev Lett ; 131(19): 191001, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38000434

RESUMO

Detailed measurements of the spectral structure of cosmic-ray electrons and positrons from 10.6 GeV to 7.5 TeV are presented from over 7 years of observations with the CALorimetric Electron Telescope (CALET) on the International Space Station. The instrument, consisting of a charge detector, an imaging calorimeter, and a total absorption calorimeter with a total depth of 30 radiation lengths at normal incidence and a fine shower imaging capability, is optimized to measure the all-electron spectrum well into the TeV region. Because of the excellent energy resolution (a few percent above 10 GeV) and the outstanding e/p separation (10^{5}), CALET provides optimal performance for a detailed search of structures in the energy spectrum. The analysis uses data up to the end of 2022, and the statistics of observed electron candidates has increased more than 3 times since the last publication in 2018. By adopting an updated boosted decision tree analysis, a sufficient proton rejection power up to 7.5 TeV is achieved, with a residual proton contamination less than 10%. The observed energy spectrum becomes gradually harder in the lower energy region from around 30 GeV, consistently with AMS-02, but from 300 to 600 GeV it is considerably softer than the spectra measured by DAMPE and Fermi-LAT. At high energies, the spectrum presents a sharp break around 1 TeV, with a spectral index change from -3.15 to -3.91, and a broken power law fitting the data in the energy range from 30 GeV to 4.8 TeV better than a single power law with 6.9 sigma significance, which is compatible with the DAMPE results. The break is consistent with the expected effects of radiation loss during the propagation from distant sources (except the highest energy bin). We have fitted the spectrum with a model consistent with the positron flux measured by AMS-02 below 1 TeV and interpreted the electron+positron spectrum with possible contributions from pulsars and nearby sources. Above 4.8 TeV, a possible contribution from known nearby supernova remnants, including Vela, is addressed by an event-by-event analysis providing a higher proton-rejection power than a purely statistical analysis.

3.
Phys Rev Lett ; 130(21): 211001, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37295105

RESUMO

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate. We show that this observed charge-sign dependence is reproduced by a numerical "drift model" of the GCR transport in the heliosphere. This is a clear signature of the drift effect on the long-term solar modulation observed with a single detector.


Assuntos
Radiação Cósmica , Voo Espacial , Telescópios , Prótons , Elétrons
4.
Phys Rev Lett ; 130(17): 171002, 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37172251

RESUMO

We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument in operation on the International Space Station since 2015. The observation period covered by this analysis spans from October 13, 2015, to April 30, 2022 (2392 days). The very wide dynamic range of CALET allowed for the collection of helium data over a large energy interval, from ∼40 GeV to ∼250 TeV, for the first time with a single instrument in low Earth orbit. The measured spectrum shows evidence of a deviation of the flux from a single power law by more than 8σ with a progressive spectral hardening from a few hundred GeV to a few tens of TeV. This result is consistent with the data reported by space instruments including PAMELA, AMS-02, and DAMPE and balloon instruments including CREAM. At higher energy we report the onset of a softening of the helium spectrum around 30 TeV (total kinetic energy). Though affected by large uncertainties in the highest energy bins, the observation of a flux reduction turns out to be consistent with the most recent results of DAMPE. A double broken power law is found to fit simultaneously both spectral features: the hardening (at lower energy) and the softening (at higher energy). A measurement of the proton to helium flux ratio in the energy range from 60 GeV/n to about 60 TeV/n is also presented, using the CALET proton flux recently updated with higher statistics.

5.
Phys Rev Lett ; 129(10): 101102, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36112450

RESUMO

A precise measurement of the cosmic-ray proton spectrum with the Calorimetric Electron Telescope (CALET) is presented in the energy interval from 50 GeV to 60 TeV, and the observation of a softening of the spectrum above 10 TeV is reported. The analysis is based on the data collected during ∼6.2 years of smooth operations aboard the International Space Station and covers a broader energy range with respect to the previous proton flux measurement by CALET, with an increase of the available statistics by a factor of ∼2.2. Above a few hundred GeV we confirm our previous observation of a progressive spectral hardening with a higher significance (more than 20 sigma). In the multi-TeV region we observe a second spectral feature with a softening around 10 TeV and a spectral index change from -2.6 to -2.9 consistently, within the errors, with the shape of the spectrum reported by DAMPE. We apply a simultaneous fit of the proton differential spectrum which well reproduces the gradual change of the spectral index encompassing the lower energy power-law regime and the two spectral features observed at higher energies.

6.
Phys Rev Lett ; 128(13): 131103, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35426700

RESUMO

The relative abundance of cosmic ray nickel nuclei with respect to iron is by far larger than for all other transiron elements; therefore it provides a favorable opportunity for a low background measurement of its spectrum. Since nickel, as well as iron, is one of the most stable nuclei, the nickel energy spectrum and its relative abundance with respect to iron provide important information to estimate the abundances at the cosmic ray source and to model the Galactic propagation of heavy nuclei. However, only a few direct measurements of cosmic-ray nickel at energy larger than ∼3 GeV/n are available at present in the literature, and they are affected by strong limitations in both energy reach and statistics. In this Letter, we present a measurement of the differential energy spectrum of nickel in the energy range from 8.8 to 240 GeV/n, carried out with unprecedented precision by the Calorimetric Electron Telescope (CALET) in operation on the International Space Station since 2015. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The particle's energy is measured by a homogeneous calorimeter (1.2 proton interaction lengths, 27 radiation lengths) preceded by a thin imaging section (3 radiation lengths) providing tracking and energy sampling. This Letter follows our previous measurement of the iron spectrum [1O. Adriani et al. (CALET Collaboration), Phys. Rev. Lett. 126, 241101 (2021).PRLTAO0031-900710.1103/PhysRevLett.126.241101], and it extends our investigation on the energy dependence of the spectral index of heavy elements. It reports the analysis of nickel data collected from November 2015 to May 2021 and a detailed assessment of the systematic uncertainties. In the region from 20 to 240 GeV/n our present data are compatible within the errors with a single power law with spectral index -2.51±0.07.

7.
Phys Rev Lett ; 129(25): 251103, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36608255

RESUMO

We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux in an energy interval from 8.4 GeV/n to 3.8 TeV/n based on the data collected by the Calorimetric Electron Telescope (CALET) during ∼6.4 yr of operation on the International Space Station. An update of the energy spectrum of carbon is also presented with an increase in statistics over our previous measurement. The observed boron flux shows a spectral hardening at the same transition energy E_{0}∼200 GeV/n of the C spectrum, though B and C fluxes have different energy dependences. The spectral index of the B spectrum is found to be γ=-3.047±0.024 in the interval 25

8.
Phys Rev Lett ; 126(24): 241101, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34213922

RESUMO

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray iron over a wide energy interval. In this Letter a measurement of the iron spectrum is presented in the range of kinetic energy per nucleon from 10 GeV/n to 2.0 TeV/n allowing the inclusion of iron in the list of elements studied with unprecedented precision by space-borne instruments. The measurement is based on observations carried out from January 2016 to May 2020. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The energy is measured by a homogeneous calorimeter with a total equivalent thickness of 1.2 proton interaction lengths preceded by a thin (3 radiation lengths) imaging section providing tracking and energy sampling. The analysis of the data and the detailed assessment of systematic uncertainties are described and results are compared with the findings of previous experiments. The observed differential spectrum is consistent within the errors with previous experiments. In the region from 50 GeV/n to 2 TeV/n our present data are compatible with a single power law with spectral index -2.60±0.03.

9.
Phys Rev Lett ; 125(25): 251102, 2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33416351

RESUMO

In this paper, we present the measurement of the energy spectra of carbon and oxygen in cosmic rays based on observations with the Calorimetric Electron Telescope on the International Space Station from October 2015 to October 2019. Analysis, including the detailed assessment of systematic uncertainties, and results are reported. The energy spectra are measured in kinetic energy per nucleon from 10 GeV/n to 2.2 TeV/n with an all-calorimetric instrument with a total thickness corresponding to 1.3 nuclear interaction length. The observed carbon and oxygen fluxes show a spectral index change of ∼0.15 around 200 GeV/n established with a significance >3σ. They have the same energy dependence with a constant C/O flux ratio 0.911±0.006 above 25 GeV/n. The spectral hardening is consistent with that measured by AMS-02, but the absolute normalization of the flux is about 27% lower, though in agreement with observations from previous experiments including the PAMELA spectrometer and the calorimetric balloon-borne experiment CREAM.

10.
Bone ; 128: 112037, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31400472

RESUMO

Bone loss in astronauts during spaceflight may be a risk factor for osteoporosis, fractures and renal stone formation. We previously reported that the bisphosphonate alendronate, combined with exercise that included an Advanced Resistive Exercise Device (ARED), can prevent or attenuate group mean declines in areal bone mineral density (aBMD) measured soon after ~ 6-month spaceflights aboard the International Space Station (ISS). It is unclear however if the beneficial effects on postflight aBMD were due to individual or combined effects of alendronate and ARED. Hence, 10 additional ISS astronauts were recruited who used the ARED (ARED group) without drug administration using similar measurements in the previous study, i.e., densitometry, biochemical assays and analysis of finite element (FE) models. In addition densitometry data (DXA and QCT only) were compared to published data from crewmembers (n = 14-18) flown prior to in-flight access to the ARED (Pre-ARED). Group mean changes from preflight (± SD %) were used to evaluate effects of countermeasures as sequentially modified on the ISS (i.e., Pre-ARED vs. ARED; ARED vs. Bis+ARED). Spaceflight durations were not significantly different between groups. Postflight bone density measurements were significantly reduced from preflight in the Pre-ARED group. As previously reported, combined Bis+ARED prevented declines in all DXA and QCT hip densitometry and in estimates of FE hip strengths; increased the aBMD of lumbar spine; and prevented elevations in urinary markers for bone resorption during spaceflight. ARED without alendronate partially attenuated declines in bone mass but did not suppress biomarkers for bone resorption or prevent trabecular bone loss. Resistive exercise in the ARED group did not prevent declines in hip trabecular vBMD, but prevented reductions in cortical vBMD of the femoral neck, in FE estimate of hip strength for non-linear stance (NLS) and in aBMD of the femoral neck. We conclude that a bisphosphonate, when combined with resistive exercise, enhances the preservation of bone mass because of the added suppression of bone resorption in trabecular bone compartment not evident with ARED alone.


Assuntos
Densidade Óssea/fisiologia , Terapia por Exercício/métodos , Voo Espacial , Absorciometria de Fóton , Adulto , Alendronato/uso terapêutico , Astronautas , Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/tratamento farmacológico , Doenças Ósseas Metabólicas/prevenção & controle , Doenças Ósseas Metabólicas/terapia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/tratamento farmacológico , Osteoporose/prevenção & controle , Osteoporose/terapia , Ausência de Peso/efeitos adversos
11.
Phys Rev Lett ; 122(18): 181102, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31144869

RESUMO

In this paper, we present the analysis and results of a direct measurement of the cosmic-ray proton spectrum with the CALET instrument onboard the International Space Station, including the detailed assessment of systematic uncertainties. The observation period used in this analysis is from October 13, 2015 to August 31, 2018 (1054 days). We have achieved the very wide energy range necessary to carry out measurements of the spectrum from 50 GeV to 10 TeV covering, for the first time in space, with a single instrument the whole energy interval previously investigated in most cases in separate subranges by magnetic spectrometers (BESS-TeV, PAMELA, and AMS-02) and calorimetric instruments (ATIC, CREAM, and NUCLEON). The observed spectrum is consistent with AMS-02 but extends to nearly an order of magnitude higher energy, showing a very smooth transition of the power-law spectral index from -2.81±0.03 (50-500 GeV) neglecting solar modulation effects (or -2.87±0.06 including solar modulation effects in the lower energy region) to -2.56±0.04 (1-10 TeV), thereby confirming the existence of spectral hardening and providing evidence of a deviation from a single power law by more than 3σ.

12.
Phys Rev Lett ; 120(26): 261102, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004739

RESUMO

Extended results on the cosmic-ray electron + positron spectrum from 11 GeV to 4.8 TeV are presented based on observations with the Calorimetric Electron Telescope (CALET) on the International Space Station utilizing the data up to November 2017. The analysis uses the full detector acceptance at high energies, approximately doubling the statistics compared to the previous result. CALET is an all-calorimetric instrument with a total thickness of 30 X_{0} at normal incidence and fine imaging capability, designed to achieve large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum in the region below 1 TeV shows good agreement with Alpha Magnetic Spectrometer (AMS-02) data. In the energy region below ∼300 GeV, CALET's spectral index is found to be consistent with the AMS-02, Fermi Large Area Telescope (Fermi-LAT), and Dark Matter Particle Explorer (DAMPE), while from 300 to 600 GeV the spectrum is significantly softer than the spectra from the latter two experiments. The absolute flux of CALET is consistent with other experiments at around a few tens of GeV. However, it is lower than those of DAMPE and Fermi-LAT with the difference increasing up to several hundred GeV. The observed energy spectrum above ∼1 TeV suggests a flux suppression consistent within the errors with the results of DAMPE, while CALET does not observe any significant evidence for a narrow spectral feature in the energy region around 1.4 TeV. Our measured all-electron flux, including statistical errors and a detailed breakdown of the systematic errors, is tabulated in the Supplemental Material in order to allow more refined spectral analyses based on our data.

13.
Ann Oncol ; 28(4): 798-803, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27998971

RESUMO

Background: S-288310, a cancer peptide vaccine composed of two HLA-A*24:02-restricted peptides derived from two oncoantigens, DEP domain-containing 1 (DEPDC1) and M-phase phosphoprotein 1 (MPHOSPH1), was investigated in urothelial carcinoma (UC) of the bladder. Patients and methods: Thirty eight HLA-A*24:02-positive patients with progressive UC were enrolled in this study. In the phase I part of the study, three patients each were treated with S-288310 at 1 mg or 2 mg/peptide subcutaneously once a week to evaluate safety and tolerability. In the phase II, 32 patients were randomized to receive either 1 mg or 2 mg to evaluate the difference in cytotoxic T lymphocytes (CTL) induction and safety. Results: S-288310 was safe and well tolerated in the phase I. Of 27 patients evaluable for immune responses in the phase II, there was no difference in CTL induction rate between the 1 mg (100%) and 2 mg (80.0%) groups. Of 32 patients receiving S-288310 in the phase II, the most frequent drug-related AE was the injection site reaction that was observed in 29 patients (90.6%), but none of the patients discontinued administration due to these reactions and no dose relationship in the frequency and severity was observed. The objective response rate of the 32 patients was 6.3% and the disease control rate was 56.3%. The median overall survival (OS) rates for patients vaccinated with S-288310 after one regimen of chemotherapy, 2 regimens, or 3 or more were 14.4, 9.1 and 3.7 months, respectively, and 32.2% of patients post first-line treatment were alive at 2 years. OS of patients who showed CTL induction to both peptides was longer than that of those with CTL induction to no or one peptide. Conclusion: S-288310 was well-tolerated and effectively induced peptide-specific CTLs, which were correlated with longer survival for patients with UC of the bladder. Trial registration ID: JapicCTI-090980.


Assuntos
Vacinas Anticâncer/uso terapêutico , Carcinoma de Células de Transição/terapia , Linfócitos T Citotóxicos/imunologia , Neoplasias da Bexiga Urinária/terapia , Idoso , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/uso terapêutico , Vacinas Anticâncer/imunologia , Intervalo Livre de Doença , Feminino , Antígeno HLA-A24/imunologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/uso terapêutico
14.
Urolithiasis ; 44(4): 299-310, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26721697

RESUMO

Several experimental and animal studies have demonstrated that substances rich in antioxidants can reduce the physicochemical and peroxidative risk factors for calcium oxalate (CaOx) renal stone formation in urine and blood. However, there are very few such investigations in humans. In the present pilot study, two varieties of tea, a green one from Japan (JGT) and a herbal one from South Africa (Rooibos) (RT), both rich in antioxidants, were administered to a group of CaOx stone formers (SF) (n = 8) for 30 days. Both teas were analysed for polyphenols by high-performance liquid chromatography and for minerals by plasma atomic and optical emission spectroscopy. 24 h urines (baseline and day 30) were analysed for lithogenic factors. CaOx metastable limits and crystal nucleation and growth kinetics were also determined in each urine sample. Deposited crystals were inspected by scanning electron microscopy. Blood samples were collected (baseline and day 30). Biomarkers of oxidative stress including plasma and urinary thiobarbituric acid reactive substances (TBARS) and urinary N-acetyl-ß-D-glucosaminidase (NAG) were also determined. Urinary physicochemical risk factors were also investigated after ingestion of RT for 30 days in two control groups (CG1 and CG2), the latter one of which consisted of habitual JGT drinkers. Statistical analyses were performed using Wilcoxon signed rank tests and Mann-Whitney tests for paired and independent measurements, respectively. Several flavonoids and catechins were quantified in RT and JGT, respectively, confirming that both teas are rich sources of antioxidants. Mineral content was found to be far below dietary reference intakes. There were no significant changes in any of the urinary physicochemical or peroxidative risk factors in the control groups or in SF, except for the supersaturation (SS) of brushite (Bru) which decreased in the latter group after ingestion of JGT. Crystal morphology showed a tendency to change from mixed CaOx mono- and di-hydrate to monohydrate after ingestion of each tea. Since the latter form has a stronger binding affinity for epithelial cells, this effect is not protective. Analysis of the physicochemical and peroxidative risk factors in CG1 and CG2 did not reveal any evidence of a synergistic effect between the two teas. Paradoxically, baseline risk factors in the habitual JGT control group were significantly raised relative to those in CG1. Our preliminary results suggest that ingestion of RT and JGT does not reduce the risk factors for CaOx stone formation in humans, but these findings need to be tested in further studies involving much larger sample sizes.


Assuntos
Antioxidantes/análise , Antioxidantes/uso terapêutico , Nefrolitíase/epidemiologia , Nefrolitíase/prevenção & controle , Chá/química , Chás de Ervas/análise , Adolescente , Adulto , Fenômenos Químicos , Humanos , Masculino , Oxirredução , Projetos Piloto , Fatores de Risco , Adulto Jovem
15.
Clin Radiol ; 68(6): 595-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23384503

RESUMO

AIM: To evaluate magnetic resonance imaging (MRI) findings of granulomatous prostatitis (GP) developing after intravesical Bacillus Calmette-Guérin (BCG) therapy. MATERIALS AND METHODS: Ten patients with pathologically proven GP underwent prostatic MRI. Lesion shape and signal intensity (SI) were evaluated on T2-weighted (T2WI), T1WI, and diffusion-weighted imaging (DWI). RESULTS: Polygonal nodular lesions with notches, diffuse lesions, and cystic lesions with mural nodules were seen in two, six, and one patients, respectively. The remaining patient had a diffuse and cystic lesion. All diffuse lesions showed higher SI than muscle on T1WI and higher SI than the normal peripheral zone (PZ) on DWI. On T2WI, six of seven diffuse lesions showed a slightly lower SI than bone marrow and the remaining one lesion was iso-intense. All nodular lesions showed a low SI similar to muscle on T2WI and were iso-intense to muscle on T1WI. On DWI, two each of the four nodular lesions showed slightly lower SI and slightly higher SI than the normal PZ, respectively. All contents within the cyst and mural nodules showed markedly high and low SI on T2WI, respectively. On DWI, all fluids within cysts showed markedly high SI. One each of the mural nodules showed slightly higher SI and slightly lower SI than the normal PZ on DWI. CONCLUSION: Three main MRI patterns of GP were identified: diffuse, nodular, and cystic with mural nodule; among them, the diffuse type was the most common. Cystic lesions with mural nodules could accompany the lesion.


Assuntos
Vacina BCG/efeitos adversos , Granuloma/induzido quimicamente , Prostatite/induzido quimicamente , Neoplasias da Bexiga Urinária/tratamento farmacológico , Administração Intravesical , Idoso , Idoso de 80 Anos ou mais , Vacina BCG/administração & dosagem , Vacina BCG/uso terapêutico , Imagem de Difusão por Ressonância Magnética , Granuloma/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Próstata/patologia , Prostatite/patologia , Estudos Retrospectivos
16.
Osteoporos Int ; 24(7): 2105-14, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23334732

RESUMO

UNLABELLED: We report the results of alendronate ingestion plus exercise in preventing the declines in bone mass and strength and elevated levels of urinary calcium and bone resorption in astronauts during 5.5 months of spaceflight. INTRODUCTION: This investigation was an international collaboration between NASA and the JAXA space agencies to investigate the potential value of antiresorptive agents to mitigate the well-established bone changes associated with long-duration spaceflight. METHODS: We report the results from seven International Space Station (ISS) astronauts who spent a mean of 5.5 months on the ISS and who took an oral dose of 70 mg of alendronate weekly starting 3 weeks before flight and continuing throughout the mission. All crewmembers had available for exercise a treadmill, cycle ergometer, and a resistance exercise device. Our assessment included densitometry of multiple bone regions using X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and assays of biomarkers of bone metabolism. RESULTS: In addition to pre- and post-flight measurements, we compared our results to 18 astronauts who flew ISS missions and who exercised using an early model resistance exercise device, called the interim resistance exercise device, and to 11 ISS astronauts who exercised using the newer advanced resistance exercise device (ARED). Our findings indicate that the ARED provided significant attenuation of bone loss compared with the older device although post-flight decreases in the femur neck and hip remained. The combination of the ARED and bisphosphonate attenuated the expected decline in essentially all indices of altered bone physiology during spaceflight including: DXA-determined losses in bone mineral density of the spine, hip, and pelvis, QCT-determined compartmental losses in trabecular and cortical bone mass in the hip, calculated measures of fall and stance computed bone strength of the hip, elevated levels of bone resorption markers, and urinary excretion of calcium. CONCLUSIONS: The combination of exercise plus an antiresoptive drug may be useful for protecting bone health during long-duration spaceflight.


Assuntos
Alendronato/uso terapêutico , Conservadores da Densidade Óssea/uso terapêutico , Terapia por Exercício/métodos , Osteoporose/prevenção & controle , Voo Espacial , Absorciometria de Fóton/métodos , Adulto , Alendronato/administração & dosagem , Biomarcadores/sangue , Biomarcadores/urina , Composição Corporal/fisiologia , Densidade Óssea/efeitos dos fármacos , Densidade Óssea/fisiologia , Conservadores da Densidade Óssea/administração & dosagem , Reabsorção Óssea/etiologia , Reabsorção Óssea/prevenção & controle , Terapia Combinada , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/etiologia , Osteoporose/fisiopatologia , Ausência de Peso/efeitos adversos
17.
Br J Pharmacol ; 152(8): 1228-38, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17934514

RESUMO

BACKGROUND AND PURPOSE: We have investigated the mechanisms underlying the paradoxical ability of the antispasmodic, alverine, to enhance spontaneous activity in smooth muscles while suppressing evoked activity. EXPERIMENTAL APPROACH: The effects of alverine on spontaneous and induced contractile activity were examined in preliminary experiments with various smooth muscles. More detailed effects were also investigated by recording membrane potential, intracellular Ca2+ concentration ([Ca2+]i) and tension from single-bundle detrusor smooth muscle (DSM) of the guinea-pig urinary bladder. KEY RESULTS: Alverine (10 microM) increased the frequency and amplitude of spontaneous action potentials, transient increases in [Ca2+]i and associated contractions. Alverine also decreased action potential rate of decay, suggesting inhibition of L-type Ca channel inactivation. Charybdotoxin (50 nM) but neither cyclopiazonic acid (10 microM) nor Bay K 8644 (10 microM) attenuated alverine-induced enhancement of spontaneous contractions. Alverine suppressed contractions produced by high K (40 mM) or ACh (10 microM), without affecting electrical responses and with little suppression of increases in [Ca2+]i. This feature was very similar to that of the effects of the Rho kinase inhibitor Y-27632 (10 microM). CONCLUSIONS AND IMPLICATIONS: Alverine may increase Ca influx during action potentials due to inhibition of the inactivation of L-type Ca channels, but may also suppress evoked activity by inhibiting the sensitivity of contractile proteins to Ca2+. The proportional contribution of Ca-dependent and Ca-independent contractions in DSM may differ between spontaneous and evoked activity, necessitating further investigations into the interactions between these pathways for assessing the therapeutic potential of alverine to treat DSM dysfunction.


Assuntos
Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Propilaminas/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo L/efeitos dos fármacos , Canais de Cálcio Tipo L/metabolismo , Relação Dose-Resposta a Droga , Cobaias , Humanos , Masculino , Músculo Liso/metabolismo , Parassimpatolíticos/administração & dosagem , Propilaminas/administração & dosagem
18.
Kidney Int ; 72(5): 592-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17519954

RESUMO

Osteopontin (OPN) is one of the glycosylated phosphoproteins produced in the kidney that can modulate nephrolithiasis. We had previously found a modest association between OPN gene polymorphisms and the risk for urinary stone formation. In order to determine if sequence variants within the OPN gene could be linked to the risk of nephrolithiasis; we sequenced the entire OPN gene of 45 stone forming patients and 54 control patients of Japanese ancestry. We identified 61 polymorphisms and of these evaluated four haplotype-tagging single nucleotide polymorphisms in a total of 126 kidney stone cases and 214 healthy individuals; all of Japanese ancestry. There was a significant association of two of these haplotypes located in the OPN promoter with the relative probability of nephrolithiasis; one of increased and one of reduced risk. Our findings provide potential support for significant increased and decreased associations between OPN gene haplotypes and the relative potential of stone formation in the Japanese population. We suggest that such genetic findings may help to clarify the function of OPN in nephrolithiasis.


Assuntos
Haplótipos , Nefrolitíase/genética , Osteopontina/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Humanos , Japão , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA
19.
Diabet Med ; 23(6): 617-22, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16759302

RESUMO

AIMS: Recent studies have provided increasing evidence that hepatocyte growth factor (HGF) has a pathophysiological role in the development of diabetic complications. We set out to determine the relationship between serum HGF and risk factors for macroangiopathy including carotid atherosclerosis. Carotid atherosclerosis is an established and important risk factor for both cerebral and coronary artery diseases. METHODS: We studied 89 patients (48 males, 41 females, mean age 62.5 +/- 10.3 years) with Type 2 diabetes (DM). RESULTS: Serum levels of HGF correlated positively with both intimal-media thickness (IMT) (r = 0.24, P = 0.0248) and plaque score (r = 0.27, P = 0.0126). In multiple regression analysis, serum HGF was associated independently with IMT (standardized beta = 0.28, P = 0.0499). We also found that both IMT and plaque score were higher in patients with ischaemic heart disease (IHD) than in patients without IHD, and that plaque score in patients with lacunar infarcts was higher than in patients without lacunar infarcts. CONCLUSIONS: Serum HGF concentration may be a new marker of atherosclerotic complications in patients with Type 2 DM.


Assuntos
Doenças das Artérias Carótidas/sangue , Diabetes Mellitus Tipo 2/sangue , Fator de Crescimento de Hepatócito/sangue , Fatores Etários , Idoso , Biomarcadores/sangue , Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/diagnóstico por imagem , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Feminino , Humanos , Hipertensão/sangue , Hipertensão/complicações , Hipertensão/diagnóstico por imagem , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Isquemia Miocárdica/sangue , Isquemia Miocárdica/complicações , Isquemia Miocárdica/diagnóstico por imagem , Fatores de Risco , Sístole , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Ultrassonografia
20.
Spinal Cord ; 43(5): 269-77, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15655568

RESUMO

STUDY DESIGN: Clinical case report with comments by colleagues from Sweden, Poland, Spain, Brazil, Japan, Belgium and Switzerland. OBJECTIVES: To discuss the role of disodium etidronate therapy for prevention of calcium phosphate vesical calculi in persons with spinal cord injury, who have hypercalciuria and biochemical evidence of increased bone resorption. SETTING: Regional Spinal Injuries Centre, Southport, UK. METHODS: A 21-year-old male sustained paraplegia (T-10; ASIA scale: A) in a road traffic accident in June 2001. He had an indwelling urethral catheter until the end of August 2001, when he started self-catheterisation. He developed bladder stones and electrohydraulic lithotripsy (EHL) was performed in May 2002. All stone fragments were removed. Recurrence of vesical calculi was noted in October 2002. These stones were fragmented by lithoclast lithotripsy in two sessions, in December 2002 and February 2003; all stone fragments were removed at the end of the second session. This patient reverted to indwelling catheter drainage when vesical calculi recurred. In September 2003, X-ray of the abdomen showed recurrence of vesical calculi. By February 2004, the stones had increased in size and number. EHL of vesical calculi was again performed in April 2004. Complete clearance was achieved. RESULTS: A 24-h urinalysis detected hypercalciuria--18.7 mmol/day (reference range: 2.5-7.5). Biochemical analysis of vesical calculus revealed calcium phosphate (85%) and magnesium ammonium phosphate (15%). Plasma C-terminal telopeptide (CTX) was increased - 1.06 ng/ml (reference range: 0.1-0.5 ng/ml). Free deoxypyridinoline/creatinine ratio (fDPD/Cr) in urine was also increased - 20.2 (reference range: 2.3-5.4). In April 2004, this patient was prescribed disodium etidronate 400 mg day. Nearly 3 months after commencing therapy with etidronate, plasma CTX decreased to 0.87 ng/ml. fDPD/Cr in urine also decreased to 12.4. After 4 months of etidronate therapy, 24-h urinary calcium excretion had decreased to 6.1 mmol/day. CONCLUSION: Etidronate (400 mg daily) is a very effective inhibitor of calcium phosphate crystallisation. Etidronate decreased urinary excretion of calcium, an important factor in prevention of calcium phosphate bladder stones. Etidronate therapy is not a substitute for other well-established methods for prevention of vesical calculi in spinal cord injury patients, for example, large fluid intake, avoiding long-term catheter drainage. Intermittent therapy with etidronate may be considered in selected patients, in whom hypercalciuria persists after instituting nonpharmacological therapy for an adequate period, for example, early mobilisation, weight-bearing exercises, and functional electrical stimulation. However, possible side effects of etidronate, and the fact that etidronate is not licensed in United Kingdom for prevention of urolithiasis, should be borne in mind.


Assuntos
Cálcio/metabolismo , Ácido Etidrônico/uso terapêutico , Paraplegia/etiologia , Traumatismos da Medula Espinal/complicações , Cálculos Urinários/prevenção & controle , Adulto , Reabsorção Óssea/etiologia , Seguimentos , Humanos , Cooperação Internacional , Masculino , Paraplegia/metabolismo , Paraplegia/patologia , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Tomografia Computadorizada por Raios X/métodos , Cálculos da Bexiga Urinária/etiologia , Cálculos Urinários/etiologia , Cálculos Urinários/patologia
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