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1.
Rev Sci Instrum ; 95(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38573050

RESUMO

A study of the dead layer thickness and quenching factor of a plastic scintillator for use in ultracold neutron (UCN) experiments is described. Alpha spectroscopy was used to determine the thickness of a thin surface dead layer to be 630 ± 110 nm. The relative light outputs from the decay of 241Am and Compton scattering of electrons were used to extract Birks' law coefficient, yielding a kB value of 0.087 ± 0.003 mm/MeV, consistent with some previous reports for other polystyrene-based scintillators. The results from these measurements are incorporated into the simulation to show that an energy threshold of (∼9 keV) can be achieved for the UCNProBe experiment. This low threshold enables high beta particle detection efficiency and the indirect measurement of UCN. The ability to make the scintillator deuterated, accompanied by its relatively thin dead layer, gives rise to unique applications in a wide range of UCN experiments, where it can be used to trap UCN and detect charged particles in situ.

2.
Appl Radiat Isot ; 209: 111320, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38677203

RESUMO

Cd-content and temperature dependences of hyperfine fields in CdxFe3-xO4 (0 ≤ x ≤ 0.5) were investigated by means of time-differential perturbed angular correlation spectroscopy with the 111Cd(←111In) probe. It was found that Cd2+ ions selectively occupy the tetrahedral A site in the spinel structure in all the range of the present Cd content x. The magnetic transition temperature TC becomes lower with increasing x due to the interference of the long-range ordering of Fe spins as a result of expansion of the lattice constants by Cd doping. The measurement of room-temperature hyperfine fields at different x shows that the supertransferred magnetic hyperfine field (SMHF) at the probe decreases as x increases in the range of 0 ≤ x ≤ 0.5. Isothermal measurements at 15 K revealed a contrastive phenomenon for the Cd contents up to x = 0.4: the SMHF becomes great with increasing x; however, this increasing trend of the SMHF turns to reduction at x = 0.46. These observations can be explained based on the effect of Cd doping on the antiferromagnetic coupling between Fe ions in the A and B sites.

3.
Physiol Res ; 72(4): 465-473, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37795889

RESUMO

G protein-coupled receptor 81 (GPR81), a selective receptor for lactate, expresses in skeletal muscle cells, but the physiological role of GPR81 in skeletal muscle has not been fully elucidated. As it has been reported that the lactate administration induces muscle hypertrophy, the stimulation of GPR81 has been suggested to mediate muscle hypertrophy. To clarify the contribution of GPR81 activation in skeletal muscle hypertrophy, in the present study, we investigated the effect of GPR81 agonist administration on skeletal muscle mass in mice. Male C57BL/6J mice were randomly divided into control group and GPR81 agonist-administered group that received oral administration of the specific GPR81 agonist 3-Chloro-5-hydroxybenzoic acid (CHBA). In both fast-twitch plantaris and slow-twitch soleus muscles of mice, the protein expression of GPR81 was observed. Oral administration of CHBA to mice significantly increased absolute muscle weight and muscle weight relative to body weight in the two muscles. Moreover, both absolute and relative muscle protein content in the two muscles were significantly increased by CHBA administration. CHBA administration also significantly upregulated the phosphorylation level of p42/44 extracellular signal-regulated kinase-1/2 (ERK1/2) and p90 ribosomal S6 kinase (p90RSK). These observations suggest that activation of GRP81 stimulates increased the mass of two types of skeletal muscle in mice in vivo. Lactate receptor GPR81 may positively affect skeletal muscle mass through activation of ERK pathway.


Assuntos
Ácido Láctico , Músculo Esquelético , Camundongos , Masculino , Animais , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Receptores Acoplados a Proteínas G , Hipertrofia/metabolismo
4.
Res Sq ; 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37461488

RESUMO

Microglia and brain-derived neurotrophic factor (BDNF) are essential for the neuroplasticity that characterizes critical developmental periods. The experience-dependent development of social behaviors-associated with the medial prefrontal cortex (mPFC)-has a critical period during the juvenile period in mice. However, whether microglia and BDNF affect social development remains unclear. Herein, we aimed to elucidate the effects of microglia-derived BDNF on social behaviors and mPFC development. Mice that underwent social isolation during p21-p35 had increased Bdnf in the microglia accompanied by reduced adulthood sociability. Additionally, transgenic mice overexpressing microglia Bdnf-regulated using doxycycline at different time points-underwent behavioral, electrophysiological, and gene expression analyses. In these mice, long-term overexpression of microglia BDNF impaired sociability and excessive mPFC inhibitory neuronal circuit activity. However, administration of doxycycline to normalize BDNF from p21 normalized sociability and electrophysiological functions; this was not observed when BDNF was normalized from a later age (p45-p50). To evaluate the possible role of BDNF in human sociability, we analyzed the relationship between adverse childhood experiences and BDNF expression in human macrophages, a possible substitute for microglia. Results show that adverse childhood experiences positively correlated with BDNF expression in M2 but not M1 macrophages. Thus, microglia BDNF might regulate sociability and mPFC maturation in mice during the juvenile period. Furthermore, childhood experiences in humans may be related to BDNF secretion from macrophages.

5.
J Neonatal Perinatal Med ; 16(2): 221-226, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37092238

RESUMO

BACKGROUND: A few studies have been reported on the influence of fetal hiccups on umbilical artery. The aim of this study is to clarify the influence of fetal hiccups on Doppler blood flow waveform (DBFW) of some fetal arteries, and to show the difference in these influences among fetal arteries. OBJECTIVE: DBFW of umbilical artery, descending aorta, and middle cerebral artery were recorded at hiccups in normal fetuses between 34th and 40th gestational weeks. The changes on DBFW were classified into three shapes by the direction and the size of the changes. Shape 1: sharp decrease but not to the baseline, Shape 2: sharp decrease to the baseline (absence), and Shape 3: reverse flow. RESULTS: At all hiccups, the changes on DBFW of these arteries were observed. These changes were classified into three shapes. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of the descending aorta and middle cerebral artery were Shape 3 whenever the hiccup occurred during cardiac cycle. CONCLUSION: The changes on DBFW of fetal arteries were observed at all hiccups. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of descending aorta and middle cerebral artery were Shape 3. This is the first study clarified the influence of fetal hiccups on DBFW of some fetal arteries, and showed the difference in these influences among fetal arteries.


Assuntos
Soluço , Feminino , Gravidez , Humanos , Velocidade do Fluxo Sanguíneo , Ultrassonografia Pré-Natal , Feto/diagnóstico por imagem , Feto/fisiologia , Artéria Cerebral Média/diagnóstico por imagem , Artérias Umbilicais/diagnóstico por imagem , Artérias Umbilicais/fisiologia
6.
Nat Commun ; 13(1): 7286, 2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36435872

RESUMO

Despite recent significant progress in real-time, large-area computer-generated holography, its memory requirements and computational loads will be hard to tackle for several decades to come with the current paradigm based on a priori calculations and bit-plane writing to a spatial light modulator. Here we experimentally demonstrate a holistic approach to serial computation and repeatable writing of computer-generated dynamic holograms without Fourier transform, using minimal amounts of computer memory. We use the ultrafast opto-magnetic recording of holographic patterns in a ferrimagnetic film with femtosecond laser pulses, driven by the on-the-fly hardware computation of a single holographic point. The intensity-threshold nature of the magnetic medium allows sub-diffraction-limited, point-by-point toggling of arbitrarily localized magnetic spots on the sample, according to the proposed circular detour-phase encoding, providing complex modulation and symmetrical suppression of upper diffractive orders and conjugated terms in holographically reconstructed 3-D images.

7.
J Eur Acad Dermatol Venereol ; 36(9): 1501-1506, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35462435

RESUMO

In the late 1960s, palmoplantar pustulosis (PPP) with sternocostoclavicular arthropathy was first described in Japan, predominantly affecting women in the perimenopausal age. In the 1970s, the chronic non-bacterial osteomyelitis and chronic recurrent multifocal osteomyelitis were initially observed in paediatric patients with approximately 70% girls. Acne fulminans accompanied by polyarthralgia have been observed since early 1970s, which almost exclusively occurs in adolescent boys. Report on spondyloarthropathy associated with hidradenitis suppurativa can be traced back to 1982. The SAPHO syndrome was coined in 1987 to lump together synovitis, acne, pustulosis, hyperostosis and osteitis to conceptualize a group of inflammatory osteocutaneous diseases of unclear etiopathogenesis and ill-defined associations spanning disparate age and gender groups. From historical view, Sasaki syndrome is proposed to replace SAPHO syndrome to represent PPP with sternocostoclavicular arthropathy in the absence of other skin manifestations. Hidradenitis suppurativa is folliculitis in pathogenesis and no longer classified as acne. PPP accompanied by psoriasis vulgaris is more likely psoriasis pustulosa palmoplantaris in dermatological aspect, and the associated arthritis is part of psoriatic arthropathy. Pathophysiology of these disorders is incompletely understood. To echo the advancement of high-throughput sequencing, splitting but not lumping of clinical findings would be a better strategy to decipher these multigenic complex inflammatory disorders.


Assuntos
Síndrome de Hiperostose Adquirida , Dermatologia , Exantema , Dermatopatias Vesiculobolhosas , Acne Vulgar/complicações , Acne Vulgar/patologia , Síndrome de Hiperostose Adquirida/classificação , Síndrome de Hiperostose Adquirida/complicações , Síndrome de Hiperostose Adquirida/patologia , Doença Crônica , Exantema/classificação , Exantema/complicações , Exantema/patologia , Hidradenite Supurativa/classificação , Hidradenite Supurativa/complicações , Hidradenite Supurativa/patologia , Humanos , Osteomielite/complicações , Osteomielite/patologia , Psoríase/complicações , Psoríase/patologia , Dermatopatias Vesiculobolhosas/classificação , Dermatopatias Vesiculobolhosas/complicações , Dermatopatias Vesiculobolhosas/patologia
8.
Rev Sci Instrum ; 93(3): 034703, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35365006

RESUMO

In semiconductor device history, a trend is observed where narrowing and increasing the number of material layers improve device functionality, with diodes, transistors, thyristors, and superlattices following this trend. While superlattices promise unique functionality, they are not widely adopted due to a technology barrier, requiring advanced fabrication, such as molecular beam epitaxy and lattice-matched materials. Here, a method to design quantum devices using amorphous materials and physical vapor deposition is presented. It is shown that the multiplication gain M depends on the number of layers of the superlattice, N, as M = kN, with k as a factor indicating the efficiency of multiplication. This M is, however, a trade-off with transit time, which also depends on N. To demonstrate, photodetector devices are fabricated on Si, with the superlattice of Se and As2Se3, and characterized using current-voltage (I-V) and current-time (I-T) measurements. For superlattices with the total layer thicknesses of 200 nm and 2 µm, the results show that k200nm = 0.916 and k2µm = 0.384, respectively. The results confirm that the multiplication factor is related to the number of superlattice layers, showing the effectiveness of the design approach.

9.
Plant Biol (Stuttg) ; 24(5): 897-909, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35301790

RESUMO

Ethylene response factors (ERFs) comprise one of the largest transcription factor families in many plant species. Tobacco (Nicotiana tabacum) ERF3 (NtERF3) and other ERF-associated amphiphilic repression (EAR) motif-containing ERFs are known to function as transcriptional repressors. NtERF3 and several repressor-type ERFs induce cell death in tobacco leaves and are also associated with a defence response against tobacco mosaic virus (TMV). We investigated whether transcriptional activator-type NtERFs function together with NtERF3 in the defence response against TMV infection by performing transient ectopic expression, together with gene expression, chromatin immunoprecipitation (ChIP) and promoter analyses. Transient overexpression of NtERF2 and NtERF4 induced cell death in tobacco leaves, albeit later than that induced by NtERF3. Fusion of the EAR motif to the C-terminal end of NtERF2 and NtERF4 abolished their cell death-inducing ability. The expression of NtERF2 and NtERF4 was upregulated at the early phase of N gene-triggered hypersensitive response (HR) against TMV infection. The cell death phenotype induced by overexpression of wild-type NtERF2 and NtERF4 was suppressed by co-expression of an EAR motif-deficient form of NtERF3. Furthermore, ChIP and promoter analyses suggested that NtERF2, NtERF3 and NtERF4 positively or negatively regulate the expression of NtERF3 by binding to its promoter region. Overall, our results revealed the cell death-inducing abilities of genes encoding activator-type NtERFs, including NtERF2 and NtERF4, suggesting that the HR-cell death signalling via the repressor-type NtERF3 is competitively but coordinately regulated by these NtERFs.


Assuntos
Nicotiana , Proteínas de Plantas , Morte Celular , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Fatores de Transcrição/metabolismo
11.
Clin Radiol ; 77(3): e231-e240, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35000763

RESUMO

AIM: To evaluate the feasibility and image quality of the double rule-out (DRO) technique using 128-row multidetector computed tomography (CT) for simultaneous evaluation of the aorta and coronary arteries in patients with acute non-specific chest pain. MATERIALS AND METHODS: Sixty-eight patients underwent electrocardiography (ECG)-gated coronary CT followed by non-ECG-gated abdominal CT. The contrast-to-noise ratio and signal-to-noise ratio between the vessels and adjacent perivascular fat tissue were calculated for both the aorta and coronary arteries. Dose-length products were recorded. Two blinded readers graded the image quality of the aorta and coronary arteries on a two-point and a four-point scale, respectively. In addition, the severity of coronary stenosis was independently analysed for each coronary vessel. RESULTS: The average attenuation was more than 350 HU for the aorta and >330 HU for the coronary arteries. The average (±standard deviation) volume of contrast media was 69.5 ± 12.5 ml. Interobserver agreement on the image quality of aortic and coronary data sets was perfect and substantial, respectively. There was almost perfect interobserver agreement for the all observations of the severity of coronary stenosis. CONCLUSION: The DRO technique with a standard volume (approximately 70 ml) of contrast media is useful for acute chest pain evaluation in patients suspected of having acute aortic syndrome or acute coronary syndrome. It is also accurate and safe while maintaining the average CT attenuation of the aorta and coronary arteries >330 HU.


Assuntos
Aorta/diagnóstico por imagem , Dor no Peito/diagnóstico por imagem , Doença das Coronárias/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Tecido Adiposo/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Angiografia Coronária/métodos , Estenose Coronária/diagnóstico por imagem , Eletrocardiografia/métodos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Razão Sinal-Ruído , Calcificação Vascular/diagnóstico por imagem
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 5051-5054, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34892342

RESUMO

In order to improve the quality of life of dialysis patients, our group have been developing an implantable hemofiltration device (IHFD) composed of multiple layers of dialysis membranes and microfluidic channels. To improve the hemodialysis performance of IHFD, preventing the negative filtration, which is caused by the oncotic pressure of blood, is mandatory. In this study, we fabricated IHFDs with five different microchannel designs and experimentally investigated the performance of each device in in vitro experiment. In addition, the successful IHFD was further evaluated by ex vivo experiments with a beagle dog. The experiments verified the effectiveness of the microchannel design, which will be used for the IHFD for in vivo experiments with pigs in the future.


Assuntos
Hemofiltração , Animais , Cães , Filtração , Humanos , Microfluídica , Qualidade de Vida , Diálise Renal , Suínos
14.
Phys Rev Lett ; 127(16): 162501, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34723594

RESUMO

We report an improved measurement of the free neutron lifetime τ_{n} using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38×10^{6} surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τ_{n} from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τ_{n} measurements and by performing a global likelihood fit to all data while self-consistently incorporating the ß-decay lifetime. Both techniques achieve consistent results and find a value τ_{n}=877.75±0.28_{stat}+0.22/-0.16_{syst} s. With this sensitivity, neutron lifetime experiments now directly address the impact of recent refinements in our understanding of the standard model for neutron decay.

15.
Animal ; 15(11): 100384, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34757251

RESUMO

Recently, automatic feeders have become popular for collecting daily feed intake data in the pig industry, making it possible to evaluate genetic effects on feed efficiency and resilience traits, expressed as day-to-day fluctuations in feeding records. This study aimed to understand the influence of genetic factors on feed efficiency traits, including residual intake and BW gain (RIG), and resilience traits, as well as to compare the differences in genetic parameter estimates among three purebred pig breeds. A total of 6 103 pigs from three breeds (Large White: 1 193 pigs, Landrace: 3 010 pigs, and Duroc: 1 900 pigs) were raised in a specific pathogen-free environment. The growth and feed intake records during the testing period were obtained using automatic feeders, and the average daily gain (ADG) and average feed intake (AFI) were calculated. Feed conversion ratio (FCR), residual feed intake (RFI), residual gain, and RIG were calculated as feed efficiency traits, and the log-transformed variance of deviation for the daily feed intake (LnVar_FI), daily occupation time (LnVar_OC), and the daily number of visits to the feeder (LnVar_VT) was calculated as resilience traits. After estimating the genetic parameters for each breed, a meta-analysis was performed to obtain the weighted mean of heritability estimates (hm2) and genetic correlation estimates (GCm) for the three breeds. The hm2 were moderate and ranged from 0.31 to 0.39 for feed efficiency traits and 0.31 to 0.40 for resilience traits, and there were no significant differences in heritability estimates among the three breeds except for AFI, RFI, and RIG. For feed efficiency traits, the FCR and RIG showed favourably moderate GCm with AFI (0.29 and -0.33, respectively) and ADG (-0.39 and 0.31, respectively). For resilience traits, the LnVar_FI and LnVar_VT showed favourably low to moderate GCm with FCR (0.33 and 0.28, respectively) and RIG (-0.37 and 0.28, respectively), and there were no genetic relationships of LnVar_OC with FCR and RIG (the absolute value of GCm was 0.01). There was no significant difference in the genetic correlation estimates among the three breeds for feed efficiency and resilience traits. Our results suggest that feed efficiency and resilience traits were heritable, and resilience traits showed favourable or no genetic correlation with feed efficiency traits. In addition, the influence of genetic factors on feed efficiency and resilience traits could be the same among breeds.


Assuntos
Ração Animal , Ingestão de Alimentos , Animais , Ingestão de Alimentos/genética , Fenótipo , Suínos/genética
18.
BJS Open ; 5(4)2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34355240

RESUMO

BACKGROUND: Hepatectomy with vascular resection (VR) for perihilar cholangiocarcinoma (PHCC) is a challenging procedure. However, only a few reports on this procedure have been published and its clinical significance has not been fully evaluated. METHODS: Patients undergoing surgical resection for PHCC from 2002-2017 were studied. The surgical outcomes of VR and non-VR groups were compared. RESULTS: Some 238 patients were included. VR was performed in 85 patients. The resected vessels were hepatic artery alone (31 patients), portal vein alone (37 patients) or both (17 patients). The morbidity rates were almost the same in the VR (49.4 per cent) and non-VR (43.8 per cent) groups (P = 0.404). The mortality rates of VR (3.5 per cent) and non-VR (3.3 per cent) were also comparable (P > 0.999). The median survival time (MST) was 45 months in the non-VR group and 36 months in VR group (P = 0.124). Among patients in whom tumour involvement was suspected on preoperative imaging and whose carbohydrate antigen 19-9 (CA19-9) value was 37 U/ml or less, MST in the VR group was significantly longer than that in the non-VR group (50 versus 34 months, P = 0.017). In contrast, when the CA19-9 value was greater than 37 U/ml, MST of the VR and non-VR groups was comparable (28 versus 29 months, P = 0.520). CONCLUSION: Hepatectomy with VR for PHCC can be performed in a highly specialized hepatobiliary centre with equivalent short- and long-term outcomes to hepatectomy without VR.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Tumor de Klatskin , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/cirurgia , Hepatectomia , Humanos , Tumor de Klatskin/cirurgia
19.
J Eur Acad Dermatol Venereol ; 35(11): 2225-2238, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34273208

RESUMO

BACKGROUND: Mogamulizumab was compared with vorinostat in the phase 3 MAVORIC trial (NCT01728805) in 372 patients with relapsed/refractory mycosis fungoides (MF) or Sézary syndrome (SS) who had failed ≥1 prior systemic therapy. Mogamulizumab significantly prolonged progression-free survival (PFS), with a superior objective response rate (ORR) vs. vorinostat. OBJECTIVES: This post hoc analysis was performed to evaluate the effect of baseline blood tumour burden on patient response to mogamulizumab. METHODS: PFS, ORR, time to next treatment (TTNT), skin response (modified Severity-Weighted Assessment Tool [mSWAT]) and safety were assessed in patients stratified by blood classification (B0 [n = 126], B1 [n = 62], or B2 [n = 184], indicating increasing blood involvement). RESULTS: Investigator-assessed PFS was longer for mogamulizumab versus vorinostat across all blood classes, significantly so for B1 and B2 patients. ORR was higher with mogamulizumab than with vorinostat in all blood classification groups and more markedly so with escalating B class (B0: 15.6% vs. 6.5%, P = 0.0549; B1: 25.8% vs. 6.5%, P = 0.2758; B2: 37.4% vs. 3.2%, P < 0.0001). TTNT was significantly longer for patients treated with mogamulizumab versus vorinostat with B1 (12.63 vs. 3.07 months; HR 0.32 [95% CI 0.16-0.67]; P = 0.0018) and B2 (13.07 vs. 3.53 months; HR 0.30 [95% CI 0.21-0.43]; P < 0.0001) blood involvement. In the mogamulizumab arm, 81 patients (43.5%) had ≥50% change in the mSWAT vs. 41 patients (22.0%) with vorinostat; mSWAT improvements with mogamulizumab occurred most often in B1 and B2 patients. Rapid, sustained reductions were seen in CD4+ CD26- cell counts and CD4:CD8 ratios in mogamulizumab patients for all B classes. Treatment-emergent adverse events were less frequent overall with mogamulizumab and similar in frequency regardless of B class. CONCLUSIONS: This post hoc analysis indicates greater clinical benefit with mogamulizumab vs. vorinostat in patients with MF and SS classified as having B1 and B2 blood involvement.


Assuntos
Micose Fungoide , Neoplasias Cutâneas , Anticorpos Monoclonais Humanizados , Humanos , Recidiva Local de Neoplasia , Carga Tumoral
20.
Osteoporos Int ; 32(12): 2533-2541, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34137899

RESUMO

Our human observational study showed that elevated arginine vasopressin levels by heavy exercise, not catecholamines, were associated with elevated serum tartrate-resistant acid phosphatase 5b (TRACP-5b). The increase in serum calcium was positively associated with percent changes of TRACP-5b, implying the involvement of bone resorption in the pathogenesis of exercise-induced hypercalcemia. INTRODUCTION: It remains unclear whether enhanced bone resorption explains exercise-induced hypercalcemia. An experimental study demonstrated that arginine vasopressin (AVP) stimulated osteoclast activity. METHODS: We conducted a prospective observational study, enrolling 65 trained healthy male officers of the Japan Self-Defense Forces (34 and 31 in waves 1 and 2, respectively). Before and after a 5-h heavy exercise, we collected laboratory data including bone markers, symptoms, and ionized calcium (iCa; wave 2 only). As blood calcium levels change after exercise, we estimated calcium (corrected calcium) levels immediately after the exercise using the correlation between blood calcium and time from the end of exercise in another cohort. RESULTS: Body weight decreased by 6.9% after the exercise. Corrected post-exercise serum total calcium (tCa) and iCa levels were significantly higher than pre-exercise levels, and 18% of participants showed hypercalcemia defined as corrected tCa >10.4 mg/dL or iCa >1.30 mmol/L. Serum tartrate-resistant acid phosphatase 5b (TRACP-5b), plasma three fractions of catecholamines, and AVP elevated significantly (median 14.3 pg/mL), while procollagen type 1 N-terminal propeptide and whole parathyroid hormone showed significant decreases. Corrected tCa increase showed a non-linear positive association with percent changes of TRACP-5b (%ΔTRACP-5b) even after adjustment for confounders. In addition, %ΔTRACP-5b was not associated with catecholamines, but with post-exercise AVP levels after adjustment for pre-exercise TRACP-5b. Symptoms of nausea or vomiting (observed in 20%) were positively associated with corrected post-exercise iCa after adjustment for post-exercise blood pH. CONCLUSION: AVP elevation may explain bone resorption and the following hypercalcemia in the setting of heavy exercise.


Assuntos
Reabsorção Óssea , Hipercalcemia , Fosfatase Ácida , Biomarcadores , Reabsorção Óssea/etiologia , Humanos , Hipercalcemia/etiologia , Isoenzimas , Masculino , Fosfatase Ácida Resistente a Tartarato , Vasopressinas
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