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1.
Nature ; 615(7954): 813-816, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36991189

RESUMO

The proton is one of the main building blocks of all visible matter in the Universe1. Among its intrinsic properties are its electric charge, mass and spin2. These properties emerge from the complex dynamics of its fundamental constituents-quarks and gluons-described by the theory of quantum chromodynamics3-5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering2. An example is the highly precise measurement of the electric charge radius of the proton6. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψ particle. We determined the gluonic gravitational form factors of the proton7,8 from our measurement. We used a variety of models9-11 and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics12. This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.

2.
Sensors (Basel) ; 24(6)2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38544173

RESUMO

Incorrect limb position while lifting heavy weights might compromise athlete success during weightlifting performance, similar to the way that it increases the risk of muscle injuries during resistance exercises, regardless of the individual's level of experience. However, practitioners might not have the necessary background knowledge for self-supervision of limb position and adjustment of the lifting position when improper movement occurs. Therefore, the computerized analysis of movement patterns might assist people in detecting changes in limb position during exercises with different loads or enhance the analysis of an observer with expertise in weightlifting exercises. In this study, hidden Markov models (HMMs) were employed to automate the detection of joint position and barbell trajectory during back squat exercises. Ten volunteers performed three lift movements each with a 0, 50, and 75% load based on body weight. A smartphone was used to record the movements in the sagittal plane, providing information for the analysis of variance and identifying significant position changes by video analysis (p < 0.05). Data from individuals performing the same movements with no added weight load were used to train the HMMs to identify changes in the pattern. A comparison of HMMs and human experts revealed between 40% and 90% agreement, indicating the reliability of HMMs for identifying changes in the control of movements with added weight load. In addition, the results highlighted that HMMs can detect changes imperceptible to the human visual analysis.


Assuntos
Treinamento Resistido , Humanos , Reprodutibilidade dos Testes , Treinamento Resistido/métodos , Levantamento de Peso/fisiologia , Postura , Extremidades , Movimento
3.
J Bone Miner Metab ; 41(1): 113-123, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36422677

RESUMO

INTRODUCTION: This study aimed to compare athletes practicing exercise in different environments with non-active young and elderly men and women regarding bone mineral density (BMD), hypothesizing that BMD values differ between athletes according to the environment of exercise practice, but those training in a low-gravitational environment have no different stimuli to BMD increasing if compared with healthy peers experiencing reduced exercise involvement, whatever the age group and sex. MATERIALS AND METHODS: 104 participants of both sexes were selected according to the environment of exercise practice [swimmers (N = 26) and judo fighters (N = 26)], and exercise level of involvement [non-active young (N = 26) and older adults (N = 26)]. Dual-energy X-ray absorptiometry provided BMD, lean mass, and fat mass (FM) for the whole body (WB), upper (UL), and lower limbs (LL). RESULTS: For the BMD in WB, UL and LL no effects of group and sex were observed (p > 0.05). Post-hoc analyses detected higher values of BMD in UL for female swimmers compared to non-active older adults (p < 0.05), while judo fighters showed higher BMD in WB, UL, and LL than other participants whatever the sex (p < 0.01). Lower FM was observed for WB, UL, and LL when swimmers and judo fighters were compared to non-active young and older female peers (p < 0.01). CONCLUSION: The findings emphasized that BMD stimuli with swimming are reduced when compared to judo, and despite the stimuli in swimming is not distinguishable from that affecting BMD in WB, UL and LL of non-active young, it is effective in differing BMD in UL among non-active older for women.


Assuntos
Composição Corporal , Osso e Ossos , Masculino , Humanos , Feminino , Idoso , Densidade Óssea , Absorciometria de Fóton , Natação , Minerais
4.
Phys Rev Lett ; 128(14): 142501, 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35476486

RESUMO

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

5.
Phys Rev Lett ; 128(13): 132501, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35426696

RESUMO

We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, and ⟨E_{lab}⟩=1.157 GeV with the Q_{weak} apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the ^{27}Al neutron radius R_{n}=2.89±0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_{n}-R_{p}=-0.04±0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the ^{27}Al weak radius R_{w}=3.00±0.15 fm, and the weak skin thickness R_{wk}-R_{ch}=-0.04±0.15 fm. The weak form factor at this Q^{2} is F_{wk}=0.39±0.04.

6.
Phys Rev Lett ; 129(4): 042501, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35939025

RESUMO

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733 fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model) fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

7.
Sensors (Basel) ; 21(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34372457

RESUMO

This study sought to evaluate the training load in different age category soccer players associated with distinct pitch size small-sided games (SSGs). Twenty-four soccer players (eight in each age category: U-12, U-15, and U-23) performed three consecutive 4 vs. 4 ball possession SSGs (SSG1: 16 × 24 m; SSG2: 20 × 30 m; and SSG3: 24 × 36 m) all with 3 min duration and 3 min rest. Subjects carried ultra-wideband-based position-tracking system devices (WIMU PRO, RealTrack System). Total distance covered increased from SSG1 to SSG3 in all age categories and predominantly in running speeds below 12 km·h-1. Moreover, distance covered in 12-18 km·h-1 running speed was different in all performed SSGs and age categories. Residual or null values were observed at 18-21 km·h-1 or above running speed, namely in U-12, the only age category where metabolic power and high metabolic load distance differences occurred throughout the performed SSGs. Edwards' TRIMP differences between age categories was only observed in SSG2 (U-12 < U-15). The design of SSGs must consider that the training load of the players differs according to their age category and metabolic assessment should be considered in parallel to external load evaluation in SSGs. Wearable technology represents a fundamental support in soccer.


Assuntos
Desempenho Atlético , Corrida , Futebol , Progressão da Doença , Frequência Cardíaca , Humanos , Descanso
8.
J Cardiovasc Electrophysiol ; 31(4): 924-933, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32108399

RESUMO

OBJECTIVE: To compare the prevalence of esophageal and periesophageal thermal injury in patients undergoing radiofrequency (RF) atrial fibrillation (AF) ablation using 8 mm tip catheters during three different esophageal protection strategies. METHODS: Forty-five consecutive patients with paroxysmal or persistent AF underwent first ablation procedure, besides esophagogastroduodenoscopy (EGD) combined with radial endosonography (EUS) performed before and after the pulmonary vein (PV) isolation. Before the procedure, patients were randomly assigned to one of three esophageal lesion protection strategies: group I-without any protective or monitoring dispositive and limiting RF applications to 30 W for 20 seconds, in left atrium posterior wall (LAPW); group II-power and time of RF delivery, up to 50 W for 20 seconds at LAPW, limited by esophageal temperature monitoring; group III-applications of RF in LAPW with fixed power application of 50 W for 20 seconds during continuous esophageal cooling. RESULTS: Baseline characteristics of patients were similar in all groups. The four PVs were isolated in 14 (93.3%), 13 (86.7%), and 15 (100%) patients, respectively in groups I, II, and III. The mean RF power was significantly higher (P < .001) in the posterior side of PVs in group III. Post-AF ablation EGD and EUS revealed two esophageal wall ulcerations and two periesophageal mediastinal edemas only in the esophageal cooling group (P = .008). CONCLUSION: Esophageal cooling balloon strategy resulted in a higher RF power energy delivery when ablating at the LA posterior wall, using 8 mm nonirrigated tip catheters under temperature mode control. Despite that, patients presented a relatively low incidence of esophageal and periesophaeal injuries.


Assuntos
Fibrilação Atrial/cirurgia , Queimaduras/prevenção & controle , Ablação por Cateter , Esôfago/lesões , Veias Pulmonares/cirurgia , Adulto , Brasil , Queimaduras/diagnóstico por imagem , Queimaduras/epidemiologia , Cateteres Cardíacos , Ablação por Cateter/efeitos adversos , Ablação por Cateter/instrumentação , Desenho de Equipamento , Esôfago/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Resultado do Tratamento
9.
Phys Rev Lett ; 125(11): 112502, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32976004

RESUMO

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° and a mean energy of 1.149 GeV. The asymmetry result is B_{n}=-5.194±0.067(stat)±0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (θ_{lab}→0) where they should be most reliable.

10.
Eur J Appl Physiol ; 120(5): 1097-1109, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32212025

RESUMO

PURPOSE: This study aims to analyze swimmers' oxygen uptake kinetics ([Formula: see text]K) and bioenergetic profiles in 50, 100, and 200 m simulated swimming events and determine which physiological variables relate with performance. METHODS: Twenty-eight well-trained swimmers completed an incremental test for maximal oxygen uptake (Peak-[Formula: see text]) and maximal aerobic velocity (MAV) assessment. Maximal trials (MT) of 50, 100, and 200-m in front crawl swimming were performed for [Formula: see text]K and bioenergetic profile. [Formula: see text]K parameters were calculated through monoexponential modeling and by a new growth rate method. The recovery phase was used along with the blood lactate concentration for bioenergetics profiling. RESULTS: Peak-[Formula: see text] (57.47 ± 5.7 ml kg-1 min-1 for male and 53.53 ± 4.21 ml kg-1 min-1 for female) did not differ from [Formula: see text]peak attained at the 200-MT for female and at the 100 and 200-MT for male. From the 50-MT to 100-MT and to the 200-MT the [Formula: see text]K presented slower time constants (8.6 ± 2.3 s, 11.5 ± 2.4 s and 16.7 ± 5.5 s, respectively), the aerobic contribution increased (~ 34%, 54% and 71%, respectively) and the anaerobic decreased (~ 66%, 46% and 29%, respectively), presenting a cross-over in the 100-MT. Both energy systems, MAV, Peak-[Formula: see text], and [Formula: see text] peak of the MT's were correlated with swimming performance. DISCUSSION: The aerobic energy contribution is an important factor for performance in 50, 100, and 200-m, regardless of the time taken to adjust the absolute oxidative response, when considering the effect on a mixed-group regarding sex. [Formula: see text]K speeding could be explained by a faster initial pacing strategy used in the shorter distances, that contributed for a more rapid increase of the oxidative contribution to the energy turnover.


Assuntos
Metabolismo Energético/fisiologia , Consumo de Oxigênio , Oxigênio/metabolismo , Desempenho Psicomotor/fisiologia , Natação/fisiologia , Adolescente , Feminino , Humanos , Cinética , Ácido Láctico/sangue , Masculino
11.
HPB (Oxford) ; 22(5): 779-786, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31677985

RESUMO

BACKGROUND: Suction (S) is commonly used to improve cell acquisition during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Slow-pull (SP) sampling is another technique that might procure good quality specimens with less bloodiness. We aimed to determine if SP improves the diagnostic yield of EUS-FNA of pancreatic masses. METHODS: Patients with pancreatic solid masses were randomized to four needle passes with both techniques in an alternate fashion. Sensitivity, specificity, positive, and negative predictive values were calculated. Cellularity and bloodiness of cytological samples were assessed and compared according to the technique. RESULTS: Sensitivity, specificity, and accuracy of suction vs. SP were 95.2% vs. 92.3%; 100% vs. 100; 95.7% vs. 93%, respectively. As to the association of methods, they were 95.6, 100 and 96%, respectively. Positive predictive values for S and SP were 100%. There was no difference in diagnostic yield between S and SP (p = 0.344). Cellularity of samples obtained with SP and Suction were equivalent in both smear evaluation (p = 0.119) and cell-block (0.980). Bloodiness of SP and suction techniques were similar as well. CONCLUSIONS: S and SP techniques provide equivalent sensitivity, specificity, and accuracy. Association of methods seems to improve diagnostic yield. Suction does not increase the bloodiness of samples compared to slow-pull.


Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/diagnóstico por imagem , Estudos Prospectivos , Sensibilidade e Especificidade , Sucção
12.
Phys Rev Lett ; 123(7): 072001, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31491124

RESUMO

We report on the measurement of the γp→J/ψp cross section from E_{γ}=11.8 GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section dσ/dt has an exponential slope of 1.67±0.39 GeV^{-2} at 10.7 GeV average energy. The LHCb pentaquark candidates P_{c}^{+} can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B(P_{c}^{+}→J/ψp) and cross sections σ(γp→P_{c}^{+})×B(P_{c}^{+}→J/ψp).

13.
Phys Rev Lett ; 123(2): 022501, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31386522

RESUMO

We present extractions of the nucleon nonsinglet moments utilizing new precision data on the deuteron F_{2} structure function at large Bjorken-x determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world datasets on the proton and deuteron at lower x measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the x range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high x data. Moreover, recent exciting developments in lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach that first calculates the quark distributions directly before determining moments.

14.
Lett Appl Microbiol ; 68(6): 480-484, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30776143

RESUMO

The Active Anthrax Detect (AAD) Rapid Test lateral flow immunoassay is a point-of-care assay that was under investigational use for detecting Bacillus anthracis capsular polypeptide (polyglutamic acid) in human blood, serum and plasma. Small sample volumes, rapid results and no refrigeration required allow for easy use in either the field or laboratory. Although the test was developed for use in suspect cases of human inhalation anthrax, its features also make it a potentially powerful tool for testing suspect animal cases. We tested animal tissue samples that were confirmed or ruled out for B. anthracis. The AAD Rapid Tests were also deployed in the field, testing animal carcasses during an anthrax outbreak in hippopotami (Hippopotamus amphibius) and Cape buffalo (Syncerus caffer) in Namibia. Evaluation of all samples showed a specificity of 82% and sensitivity of 98%. However, when the assay was used on specimens from only fresh carcasses (dead for <24 h), the specificity increased to 96%. The AAD Rapid Test is a rapid and simple screening assay, but confirmatory testing needs to be done, especially when the age of the sample (days animal has been deceased) is unknown. SIGNIFICANCE AND IMPACT OF THE STUDY: In countries where anthrax is endemic, many human outbreaks are often caused by epizootics. Earlier detection of infected animals may allow for identification of exposed people, early implementation of prevention and control methods, and ultimately lessen the number of people and animals affected. Detection of Bacillus anthracis in animal tissues using a simple, rapid and field-deployable method would allow for faster outbreak response. We evaluated a simple sample collection and processing method for use with the Active Anthrax Detect Rapid Test lateral flow immunoassay to screen dead animals for anthrax.


Assuntos
Antraz/diagnóstico , Antraz/veterinária , Bacillus anthracis/isolamento & purificação , Cápsulas Bacterianas/imunologia , Proteínas de Bactérias/sangue , Ácido Poliglutâmico/análise , Animais , Antraz/prevenção & controle , Artiodáctilos/microbiologia , Búfalos/microbiologia , Surtos de Doenças/prevenção & controle , Humanos , Imunoensaio/métodos , Namíbia , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e Especificidade
15.
Int J Obes (Lond) ; 42(1): 119, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29119964

RESUMO

This corrects the article DOI: 10.1038/ijo.2017.89.

16.
Lasers Med Sci ; 33(6): 1263-1270, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29546618

RESUMO

This study aimed to investigate the effect of prior LED sessions on the responses of cardiorespiratory parameters during the running incremental step test. Twenty-six healthy, physically active, young men, aged between 20 and 30 years, took part in this study. Participants performed two incremental load tests after placebo (PLA) and light-emitting diode application (LED), and had their gas exchange, heart rate (HR), blood lactate, and rating of perceived exertion (RPE) monitored during all tests. The PLA and LED conditions were compared using the dependent Student t test with significance set at 5%. The T test showed higher maximum oxygen uptake (VO2max) (PLA = 47.2 ± 5.7; LED = 48.0 ± 5.4 ml kg-1 min-1, trivial effect size), peak velocity (Vpeak) (PLA = 13.4 ± 1.2; LED = 13.6 ± 1.2 km h-1, trivial effect size), and lower maximum HR (PLA = 195.3 ± 3.4; LED = 193.3 ± 3.9 b min-1, moderate effect size) for LED compared to PLA conditions. Furthermore, submaximal values of HR and RPE were lower, and submaximal VO2 values were higher when LED sessions prior to the incremental step test were applied. A positive response of the previous LED application in the blood lactate disappearance was also demonstrated, especially 13 and 15 min after the test. It is concluded that LED sessions prior to exercise modify cardiorespiratory response by affecting running tolerance during the incremental step test, metabolite clearance, and RPE. Therefore, LED could be used as a prior exercise strategy to modulate oxidative response acutely in targeted muscle and enhance exercise tolerance.


Assuntos
Exercício Físico/fisiologia , Luz , Consumo de Oxigênio , Corrida/fisiologia , Adulto , Teste de Esforço , Humanos , Masculino , Placebos , Adulto Jovem
17.
Int J Obes (Lond) ; 41(8): 1232-1236, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28373674

RESUMO

BACKGROUND: Food cravings are associated with dysregulated eating behaviour and obesity, and may impede successful weight loss attempts. Gaining control over food craving is therefore a component in the management of obesity. The current paper examined whether early changes in control over food craving (assessed using the Craving Control subscale on the Control of Eating Questionnaire (CoEQ)) was predictive of weight loss in four phase 3 clinical trials investigating a sustained-release combination of naltrexone/bupropion (NB) in obese adults. The underlying component structure of the CoEQ was also examined. METHOD: In an integrated analysis of four 56-week phase 3 clinical trials, subjects completed the CoEQ and had their body weight measured at baseline and at weeks 8, 16, 28 and 56. All analyses were conducted on subjects who had complete weight and CoEQ measurements at baseline and week 56, and had completed 56 weeks of NB (n=1310) or placebo (n=736). A latent growth curve model was used to examine whether early changes in the CoEQ subscales were associated with decreases in weight loss over time. Confirmatory factor analysis (CFA) was used to determine the psychometric properties of the CoEQ. RESULTS: The factor structure of the CoEQ was consistent with previous findings with a four-factor solution being confirmed: Craving Control, Positive Mood, Craving for Sweet and Craving for Savoury with good internal consistency (Cronbach's α=0.72-0.92). Subjects with the greatest improvement in Craving Control at week 8 exhibited a greater weight loss at week 56. CONCLUSIONS: These findings highlight the importance of the experience of food cravings in the treatment of obesity and support the use of the CoEQ as a psychometric tool for the measurement of food cravings in research and the pharmacological management of obesity.


Assuntos
Fissura/fisiologia , Comportamento Alimentar/psicologia , Preferências Alimentares/psicologia , Obesidade/psicologia , Redução de Peso/fisiologia , Adulto , Bupropiona/uso terapêutico , Ensaios Clínicos Fase III como Assunto , Inibidores da Captação de Dopamina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Naltrexona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Obesidade/fisiopatologia , Obesidade/prevenção & controle , Psicometria , Inquéritos e Questionários , Resultado do Tratamento
18.
Gastrointest Endosc ; 85(1): 123-128, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27354102

RESUMO

BACKGROUND AND AIMS: Gastric per-oral endoscopic myotomy (G-POEM) recently has been reported as minimally invasive therapy for gastroparesis. The aims of this study were to report on the first multicenter experience with G-POEM and to assess the efficacy and safety of this novel procedure for patients with gastroparesis with symptoms refractory to medical therapy. METHODS: All patients with gastroparesis who underwent endoscopic pyloromyotomy (G-POEM) at 5 medical centers were included. Procedures were performed following the same principles as esophageal POEM. Clinical response was defined as improvement in gastroparetic symptoms with absence of recurrent hospitalization. Adverse events were graded according to the American Society for Gastrointestinal Endoscopy lexicon. RESULTS: A total of 30 patients with refractory gastroparesis (11 diabetic, 12 postsurgical, 7 idiopathic) underwent G-POEM. Previous therapies included Botox injection in 12, transpyloric stenting in 3, and PEG with jejunal extension (PEGJ) in 1. Nausea/vomiting were the predominant symptoms in 25 patients. Weight loss was present in 27 patients with an average of 10% loss of body weight. G-POEM was completed successfully in all 30 (100%) patients with a mean procedure time of 72 minutes (range, 35-223 min). The mean myotomy length was 2.6 ± 2.3 cm. The mean length of hospital stay was 3.3 days (range, 1-12 days). Two adverse events occurred in 2 (6.7%) patients, including 1 capnoperitoneum and 1 prepyloric ulcer, rated as mild and severe, respectively. Clinical response was observed in 26 (86%) patients during a median follow-up of 5.5 months. Four patients (2 diabetic, 1 postsurgical, 1 idiopathic cause) did not respond to G-POEM. Repeat gastric emptying scan was obtained in 17 patients, normalized in 8 (47%), and improved in 6 (35%) patients. CONCLUSION: G-POEM is a technically feasible procedure. This small non-randomized study suggests the effectiveness of G-POEM for the treatment of patients with gastroparesis refractory to medical therapy. It concomitantly results in normalization of GES in a significant proportion of treated patients.


Assuntos
Gastroparesia/cirurgia , Piloro/cirurgia , Adulto , Feminino , Esvaziamento Gástrico , Gastroparesia/tratamento farmacológico , Gastroparesia/etiologia , Gastroscopia , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Retratamento , Resultado do Tratamento
19.
Rev Gastroenterol Peru ; 37(4): 370-373, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29459809

RESUMO

Pancreatic cancer is the second most common malignancy of the gastrointestinal tract in the US, and adenocarcinoma has been identified as the most common type of pancreatic cancer. Different types of pancreatic cancers have been classified: adenocarcinoma, ductal adenosquamous carcinoma, solid pseudopapillary tumors, endocrine neoplasms, acinar cell carcinoma, squamous cell carcinoma, cystic tumors, primary lymphoma of the pancreas, and metastatic lesions of the pancreas. Adenosquamous carcinoma is extremely rare, behave in a very aggressive way and is responsible for the 1 to 4% of the pancreatic exocrine neoplastic lesions. We describe the case of an 82-years-old African American female, presenting to our institution with quantifiable weight loss (12 kg in 3 months), jaundice and abdominal pain. On admission, laboratory tests were obtained: total bilirubin: 11.07 mg/dl with a direct fraction of 10.32 mg/dl. Cross-sectional abdominal CT scan with contrast, showed a lesion localized in the pancreatic head (hypodense on T1, measuring 3.5 x 3.5 x 2.5 cm), with vascular invasion of the portal vein. EUS showed a solid, hypoechoic, not well-defined lesion (measuring 3.98 x 3.80 cm), localized between the head and neck of the pancreas. EUS-FNA was performed with a 22G needle using the fanning technique. The cytological specimens demonstrated components of both squamous carcinoma and adenocarcinoma. The patient underwent ERCP procedure, and biliary drainage was performed with an entirely covered metallic stent placement. After a month from the procedures, the patient died due to the severity of the disease. Endoscopic ultrasound has proven to be the best method to diagnose solid pancreatic lesions, including rare and aggressive type of tumors like primary adenosquamous cell carcinoma that we described in this very interesting case report.


Assuntos
Biópsia por Agulha Fina/métodos , Carcinoma Adenoescamoso/patologia , Endossonografia/métodos , Neoplasias Pancreáticas/patologia , Ultrassonografia de Intervenção/métodos , Idoso de 80 Anos ou mais , Carcinoma Adenoescamoso/diagnóstico por imagem , Carcinoma Adenoescamoso/cirurgia , Citodiagnóstico , Drenagem , Evolução Fatal , Feminino , Humanos , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/cirurgia
20.
Phys Rev Lett ; 114(19): 192503, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26024167

RESUMO

New results are reported from a measurement of π^{0} electroproduction near threshold using the p(e,e^{'}p)π^{0} reaction. The experiment was designed to determine precisely the energy dependence of s- and p-wave electromagnetic multipoles as a stringent test of the predictions of chiral perturbation theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the ϕ_{π}^{*} and θ_{π}^{*} angles in the pπ^{0} center of mass was obtained for invariant energies above threshold from 0.5 up to 15 MeV. The 4-momentum transfer Q^{2} coverage ranges from 0.05 to 0.155 (GeV/c)^{2} in fine steps. A simple phenomenological analysis of our data shows strong disagreement with p-wave predictions from ChPT for Q^{2}>0.07 (GeV/c)^{2}, while the s-wave predictions are in reasonable agreement.

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