Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 24
Filtrer
1.
Eur J Sport Sci ; 24(6): 750-757, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38874996

RÉSUMÉ

The purpose of this study was to clarify the temporal coordination between gaze, head, and arm movements during forehand rallies in table tennis. Collegiate male table tennis players (n = 7) conducted forehand rallies at a constant tempo (100, 120, and 150 bpm) using a metronome. In each tempo condition, participants performed 30 strokes (a total of 90 strokes). Gaze, head, and dominant arm (shoulder, elbow, and wrist) movements were recorded with an eye-tracking device equipped with a Gyro sensor and a 3-D motion capture system. The results showed that the effect of head movements relative to gaze movements was significantly higher than that of eye movements in the three tempo conditions. Our results indicate that head movements are closely associated with gaze movements during rallies. Furthermore, cross-correlation coefficients (CCs) between head and arm movements were more than 0.96 (maximum coefficient: 0.99). In addition, head and arm movements were synchronized during rallies. Finally, CCs between gaze and arm movements were more than 0.74 (maximum coefficient: 0.99), indicating that gaze movements are temporally coordinated with arm movements. Taken together, head movements could play important roles not only in gaze tracking but also in the temporal coordination with arm movements during table tennis forehand rallies.


Sujet(s)
Bras , Mouvements oculaires , Mouvements de la tête , Mouvement , Performance psychomotrice , Tennis , Humains , Mâle , Bras/physiologie , Jeune adulte , Mouvements de la tête/physiologie , Tennis/physiologie , Performance psychomotrice/physiologie , Mouvements oculaires/physiologie , Mouvement/physiologie , Tête/physiologie
2.
PLoS One ; 19(4): e0297649, 2024.
Article de Anglais | MEDLINE | ID: mdl-38564599

RÉSUMÉ

BACKGROUND: There is a call for gathering more evidence on the effectiveness of telerehabilitation in stroke. In particular, a previous systematic review reported substantial variability in the types of technologies used in telerehabilitation interventions. The purpose of this study will be to summarize and synthesize findings on the effects of telerehabilitation based on real-time intervention between therapist and participants for patients with stroke. METHODS AND ANALYSIS: This systematic review will follow the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement. This systematic review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) on 25 May 2023 (registration number: CRD420234265527). Electronic searches will be performed in the following databases: MEDLINE, Pubmed, Web of Science, PsycINFO and CINAHL electronic databases, using a date range from inception to November 2023. We will include only randomized controlled trials for patients diagnosed with stroke who received telerehabilitation based on real-time interaction between therapist and patients. The exploration will be restricted to publications in the English language. Physical function, activities of daily living and quality of life are the outcomes. We will examine the changes of the outcomes at baseline, at the end of the intervention, and at specific time points during the follow-up after the intervention. DISCUSSION: This systematic review will provide evidence regarding telerehabilitation for people with stroke.


Sujet(s)
Activités de la vie quotidienne , Qualité de vie , Réadaptation après un accident vasculaire cérébral , Accident vasculaire cérébral , Revues systématiques comme sujet , Téléréadaptation , Humains , Réadaptation après un accident vasculaire cérébral/méthodes , Accident vasculaire cérébral/physiopathologie
3.
Front Neurosci ; 17: 1301515, 2023.
Article de Anglais | MEDLINE | ID: mdl-38099201

RÉSUMÉ

Introduction: Within the realm of chemogenetics, a particular form of agonists targeting designer receptors exclusively activated by designer drugs (DREADDs) has emerged. Deschloroclozapine (DCZ), a recently introduced DREADDs agonist, demonstrates remarkable potency in activating targeted neurons at a lower dosage compared to clozapine-N-oxide (CNO). Methods: We conducted a comparative analysis of the effects of subcutaneously administered CNO (1 mg/kg) and DCZ (0.1 mg/kg) in our transgenic rats expressing hM3Dq and mCherry exclusively in oxytocin (OXT) neurons. Results and Discussion: Notably, DCZ exhibited a swift and robust elevation of serum OXT, surpassing the effects of CNO, with a significant increase in the area under the curve (AUC) up to 3 hours post-administration. Comprehensive assessment of brain neuronal activity, using Fos as an indicator, revealed comparable effects between CNO and DCZ. Additionally, in a neuropathic pain model, both CNO and DCZ increased the mechanical nociceptive and thermal thresholds; however, the DCZ-treated group exhibited a significantly accelerated onset of the effects, aligning harmoniously with the observed alterations in serum OXT concentration following DCZ administration. These findings emphasize the remarkable efficacy of DCZ in rats, suggesting its equivalent or potentially superior performance to CNO at considerably lower dosages, thus positioning it as a promising contender among DREADDs agonists.

4.
Hum Mov Sci ; 90: 103124, 2023 Aug.
Article de Anglais | MEDLINE | ID: mdl-37478682

RÉSUMÉ

The purpose of this study was to clarify the properties of gaze and head movements during forehand stroke in table tennis. Collegiate table tennis players (n = 12) conducted forehand strokes toward a ball launched by a skilled experimenter. A total of ten trials were conducted for the experimental task. Horizontal and vertical movements of the ball, gaze, head and eye were analyzed from the image recorded by an eye tracking device. The results showed that participants did not always keep their gaze and head position on the ball throughout the entire ball path. Our results indicate that table tennis players tend to gaze at the ball in the initial ball-tracking phase. Furthermore, there was a significant negative correlation between eye and head position especially in the vertical direction. This result suggests that horizontal VOR is suppressed more than vertical VOR in ball-tracking during table tennis forehand stroke. Finally, multiple regression analysis showed that the effect of head position to gaze position was significantly higher than that of eye position. This result indicates that gaze position during forehand stroke could be associated with head position rather than eye position. Taken together, head movements may play an important role in maintaining the ball in a constant egocentric direction in table tennis forehand stroke.


Sujet(s)
Mouvements de la tête , Tennis , Humains , Technologie d'oculométrie
5.
Medicine (Baltimore) ; 102(30): e34195, 2023 Jul 28.
Article de Anglais | MEDLINE | ID: mdl-37505172

RÉSUMÉ

RATIONALE: Corticospinal tract (CST) and corticoreticular pathway (CRP) injury patterns (i.e., the continuity of the nerve fibers) are associated with gait disturbance in post-stroke patients. In this case series study, we examined the case of 3 patients with different CST and CRP injury patterns and analyzed the characteristics of gait disturbance in each patient. PATIENT CONCERNS: Patient 1 (P1) was a 73-year-old woman who presented with paralysis of the right upper and lower extremities due to a left lacunar infarction. Patient 2 (P2) was a 41-year-old man who presented with paralysis of the right upper and lower extremities due to a left putamen hemorrhage. Patient 3 (P3) was a 57-year-old man who presented with paralysis of the left upper and lower extremities due to a right putamen hemorrhage. DIAGNOSIS: In P1, the CRP in the affected hemisphere was intact, but the CST was discontinuous. In P2, the CST in the affected hemisphere was intact, but the CRP was discontinuous. P3 was discontinuous in both CST and CRP in the affected hemisphere. OUTCOMES: Over time, all 3 patients improved to the level of gait independence, but they exhibited different gait patterns. Among them, P3 showed a markedly abnormal gait pattern that included spatiotemporal gait asymmetry, lateral shift of the trunk, and hip hiking. LESSONS: This case series study demonstrated that even if both the CST and CRP were injured, gait recovered to some extent (i.e., independent level-ground gait), but the abnormal gait pattern might remain remarkable.


Sujet(s)
Hémorragie putaminale , Accident vasculaire cérébral , Mâle , Femelle , Humains , Sujet âgé , Adulte , Adulte d'âge moyen , Tractus pyramidaux , Accident vasculaire cérébral/complications , Démarche , Paralysie
6.
Phys Ther Res ; 26(1): 17-23, 2023.
Article de Anglais | MEDLINE | ID: mdl-37181482

RÉSUMÉ

OBJECTIVE: We aimed to examine the relationship between physical performance and readmission among older patients with heart failure (HF) over the past year. METHODS: This retrospective cohort study included 325 patients with HF who were aged ≥65 years and were hospitalized for acute exacerbation between November 2017 and December 2021. We investigated age, sex, body mass index, length of hospital stay, initiation of rehabilitation, New York Heart Association (NYHA) class, Charlson comorbidity index (CCI) score, medications, cardiac/renal function, nutrition, maximal quadriceps isometric strength, grip strength, and Short Physical Performance Battery (SPPB) score. Data were analyzed using the χ2 test, Mann-Whitney U test, and logistic regression analysis. RESULTS: Altogether, 108 patients met the inclusion criteria and were divided into the non-readmission (n = 76) and readmission (n = 32) groups. The readmission group exhibited longer hospital stay, more severe NYHA class, higher CCI score, higher brain natriuretic peptide (BNP) levels, lower muscle strength, and lower SPPB score compared to the non-readmission group. In the logistic regression model, BNP level and SPPB score were independent factors associated with readmission. CONCLUSION: BNP level and SPPB score were associated with readmission in patients with HF within the past year.

7.
Heart Vessels ; 38(5): 653-661, 2023 May.
Article de Anglais | MEDLINE | ID: mdl-36484815

RÉSUMÉ

The Short Physical Performance Battery (SPPB) is a well-established tool to assess the lower extremity physical performance status. The purpose of this study is to examine the impact of brain natriuretic peptide (BNP) levels and SPPB scores on short-term readmission in older patients with heart failure (HF). This prospective cohort study enrolled 325 patients with HF who were hospitalized for acute decompensated HF between November 2017 and December 2021. Variables were analyzed using the Cox proportional hazards model, receiver operating characteristic (ROC) curve, and Kaplan-Meier analysis. The 107 patients who met the inclusion criteria were divided into readmission (within 90 days of discharge; n = 25) and non-readmission (n = 82) groups. Multivariate analysis revealed that BNP level and SPPB score were independent risk factors for readmission within 90 days after discharge. Patients were classified into three groups according to the BNP and SPPB cutoff values calculated using ROC curves. The risk of readmission was significantly higher in Group 3 (BNP ≥ 384 pg/mL and SPPB ≤ 7 points) than in Group 1 (BNP < 384 pg/mL and SPPB > 7 points; hazard ratio: 27.68, 95% confidence interval: 3.672 - 208.700, P = 0.0012). Our study showed that HF patients with high BNP levels and low SPPB scores have a dramatically increased risk of readmission within 90 days of discharge.


Sujet(s)
Défaillance cardiaque , Peptide natriurétique cérébral , Humains , Sujet âgé , Pronostic , Études prospectives , Défaillance cardiaque/diagnostic , Défaillance cardiaque/thérapie , Performance fonctionnelle physique
8.
Jpn J Compr Rehabil Sci ; 14: 78-83, 2023.
Article de Anglais | MEDLINE | ID: mdl-38196778

RÉSUMÉ

Nonaka Y, Fujii R, Tanaka S, Tabira K. Effect of cognitive impairment at admission on activities of daily living at discharge in older patients with heart failure. Jpn J Compr Rehabil Sci 2023; 14: 78‒83. Objective: Hasegawa's Dementia Scale-Revised (HDS-R) is widely used as a screening test for cognitive function in older adults. In this study, we examined the effect of cognitive impairment (CI) at admission on activities of daily living (ADL) at discharge in older patients with heart failure (HF). Methods: This retrospective observational study included 394 patients hospitalized for acute decompensated HF between April 2016 and December 2022. Data on age, sex, body mass index, length of hospital stay, initiation of rehabilitation, New York Heart Association (NYHA) class, Charlson Comorbidity Index, medication, brain natriuretic peptide levels, left ventricular ejection fraction, renal function, hemoglobin level, serum albumin level, Geriatric Nutritional Risk Index (GNRI), Barthel Index (BI), and HDS-R score were analyzed using the χ2 test, unpaired t test, Mann-Whitney U test, and multiple linear regression. Results: Among 394 patients, 102 who met the final inclusion criteria were included in the study. Based on previous studies, patients were divided into a high BI group (N = 44) and a low BI group (N = 58). Multiple linear regression analysis showed that CI at admission independently affected BI at discharge even after adjusting for confounding effects of age, NYHA class, GNRI, and BI at admission. Conclusions: Our study showed that the presence or absence of CI may influence ADL improvement in rehabilitation interventions aimed at improving ADL in older patients with HF.

9.
Commun Biol ; 5(1): 907, 2022 09 05.
Article de Anglais | MEDLINE | ID: mdl-36064593

RÉSUMÉ

Oxytocin is involved in pain transmission, although the detailed mechanism is not fully understood. Here, we generate a transgenic rat line that expresses human muscarinic acetylcholine receptors (hM3Dq) and mCherry in oxytocin neurons. We report that clozapine-N-oxide (CNO) treatment of our oxytocin-hM3Dq-mCherry rats exclusively activates oxytocin neurons within the supraoptic and paraventricular nuclei, leading to activation of neurons in the locus coeruleus (LC) and dorsal raphe nucleus (DR), and differential gene expression in GABA-ergic neurons in the L5 spinal dorsal horn. Hyperalgesia, which is robustly exacerbated in experimental pain models, is significantly attenuated after CNO injection. The analgesic effects of CNO are ablated by co-treatment with oxytocin receptor antagonist. Endogenous oxytocin also exerts anti-inflammatory effects via activation of the hypothalamus-pituitary-adrenal axis. Moreover, inhibition of mast cell degranulation is found to be involved in the response. Taken together, our results suggest that oxytocin may exert anti-nociceptive and anti-inflammatory effects via both neuronal and humoral pathways.


Sujet(s)
Analgésiques , Anti-inflammatoires , Ocytocine , Noyau paraventriculaire de l'hypothalamus , Analgésiques/métabolisme , Animaux , Anti-inflammatoires/métabolisme , Neurones GABAergiques/métabolisme , Ocytocine/métabolisme , Douleur/traitement médicamenteux , Noyau paraventriculaire de l'hypothalamus/métabolisme , Rats , Rats transgéniques
10.
Viruses ; 14(8)2022 08 06.
Article de Anglais | MEDLINE | ID: mdl-36016355

RÉSUMÉ

Feline coronaviruses (FCoVs) infect cats worldwide and cause severe systemic diseases, such as feline infectious peritonitis (FIP). FIP has a high mortality rate, and drugs approved by the Food and Drug Administration have been ineffective for the treatment of FIP. Investigating host factors and the functions required for FCoV replication is necessary to develop effective drugs for the treatment of FIP. FCoV utilizes an endosomal trafficking system for cellular entry after binding between the viral spike (S) protein and its receptor. The cellular enzymes that cleave the S protein of FCoV to release the viral genome into the cytosol require an acidic pH optimized in the endosomes by regulating cellular ion concentrations. Ionophore antibiotics are compounds that form complexes with alkali ions to alter the endosomal pH conditions. This study shows that ionophore antibiotics, including valinomycin, salinomycin, and nigericin, inhibit FCoV proliferation in vitro in a dose-dependent manner. These results suggest that ionophore antibiotics should be investigated further as potential broad-spectrum anti-FCoV agents.


Sujet(s)
Coronavirus félin , Péritonite infectieuse féline , Animaux , Antibactériens/pharmacologie , Chats , Prolifération cellulaire , Coronavirus félin/génétique , Péritonite infectieuse féline/traitement médicamenteux , Ionophores/pharmacologie
11.
Front Sports Act Living ; 4: 897373, 2022.
Article de Anglais | MEDLINE | ID: mdl-35655529

RÉSUMÉ

The purpose of this study was to clarify the properties of visual strategies for gaze, eye, and head movements in skilled table tennis players during rallies. Collegiate expert and semi-expert table tennis players conducted forehand rallies at a constant tempo using a metronome. Two tempo conditions were used in the order of 130 and 150 bpm. Participants conducted a 20-stroke rally under each tempo condition. Horizontal and vertical angles between the gaze point and ball positions at the time the ball bounced (gaze-ball angle) were analyzed with the image that was recorded by an eye tracking device equipped with Gyro sensor. Eye and head movements during rallies were also recorded with the eye tracking device and Gyro sensor, respectively. The results showed that the gaze-ball angle of expert players was significantly larger than that of semi-expert players. This result indicates that expert players tended to keep their gaze position on the ball shorter than semi-expert players. We also found that eye movements of expert players were significantly smaller than that of semi-expert players. Furthermore, as the result of multiple regression analysis, the effect of eye movements on the gaze-ball angle was significantly higher than that of head movements. This result indicates that the gaze-ball angle during table tennis rallies could be associated with eye movements rather than head movements. Our findings suggest that the visual strategies used during table tennis rallies are different between expert and semi-expert players, even though they both have more than 10 years of experience.

12.
Jpn J Compr Rehabil Sci ; 13: 49-55, 2022.
Article de Anglais | MEDLINE | ID: mdl-37859843

RÉSUMÉ

Fujii R, Tamari M, Nonaka Y, Tamiya F, Hosokawa H, Tanaka S. Influence of gait exercise using a walking-assist robot for swing-leg motion in hemiplegic stroke patients: A preliminary study focusing on the immediate effect. Jpn J Compr Rehabil Sci 2022; 13: 49-55. Objective: We analyzed the effect of gait training using a walking-assist robot that assists a subject's knee joint movement and leg swing to achieve toe clearance of the paralyzed-side lower limb during treadmill walking. Methods: The subjects were 10 hemiplegic stroke patients in a rehabilitation ward. The intervention consisted of gait training using the Welwalk WW-1000 (Welwalk) robot for 40 min. Immediately before and after this intervention, a gait analysis of the patients' treadmill walking was performed by a three-dimensional motion capture system. Statistical analyses compared the foot-to-floor distance and the shortening of hip-toe length (SHTL) of the paralyzed side before and after the intervention, and examined the relationship between the change of lower-limb joint kinematics and toe clearance before and after the intervention. Results: The post-intervention SHTL was significantly lower compared to before the intervention, and there was a significant negative correlation between the change in the SHTL and the knee flexion angle from before to after the intervention. Conclusion: Gait exercise using the Welwalk could contribute to the acquisition of more normal leg-swing strategies.

13.
J Physiol Sci ; 71(1): 18, 2021 Jun 16.
Article de Anglais | MEDLINE | ID: mdl-34134629

RÉSUMÉ

We examined whether the chemogenetic activation of endogenous arginine vasopressin (AVP) affects central nesfatin-1/NucB2 neurons, using a transgenic rat line that was previously generated. Saline (1 mL/kg) or clozapine-N-oxide (CNO, 1 mg/mL/kg), an agonist for hM3Dq, was subcutaneously administered in adult male AVP-hM3Dq-mCherry transgenic rats (300-370 g). Food and water intake were significantly suppressed after subcutaneous (s.c.) injection of CNO, with aberrant circadian rhythmicity. The percentages of Fos expression in nesfatin-1/NucB2-immunoreactive neurons were significantly increased in the hypothalamus and brainstem at 120 min after s.c. injection of CNO. Suppressed food intake that was induced by chemogenetic activation of endogenous AVP was ablated after intracerebroventricularly administered nesfatin-1/NucB2-neutralizing antibody in comparison with vehicle, without any alteration of water intake nor circadian rhythmicity. These results suggest that chemogenetic activation of endogenous AVP affects, at least in part, central nesfatin-1/NucB2 neurons and may exert anorexigenic effects in the transgenic rats.


Sujet(s)
Anorexigènes/pharmacologie , Arginine vasopressine/physiologie , Clozapine/analogues et dérivés , Consommation de boisson/effets des médicaments et des substances chimiques , Consommation alimentaire/effets des médicaments et des substances chimiques , Nucléobindines/métabolisme , Transduction du signal , Animaux , Appétit/effets des médicaments et des substances chimiques , Appétit/physiologie , Clozapine/pharmacologie , Consommation de boisson/physiologie , Consommation alimentaire/physiologie , Mâle , Nucléobindines/physiologie , Rats transgéniques , Transduction du signal/effets des médicaments et des substances chimiques , Transduction du signal/physiologie
14.
Langmuir ; 36(30): 8914-8921, 2020 Aug 04.
Article de Anglais | MEDLINE | ID: mdl-32654492

RÉSUMÉ

Photopolymerization of Langmuir monolayers composed of bifunctional acrylic liquid crystalline (LC) compounds was observed in situ by polarizing optical microscopy. In a dark state, monolayers of the LC compounds formed at an air-water or liquid-liquid interface exhibited liquid-like fluidity and in-plane optical anisotropy because of the coherent molecular tilt from the surface normal. Irradiated by UV light, the in-plane anisotropy and the liquid fluidity gradually disappeared with time, indicating the formation of the polymerized monolayers. Because the constituent molecules possess polymerizable acryloyl groups, under UV light, they are combined by acrylic polymer chains grown on the interface, which decreases the intermolecular distance and disturbs the coherent molecular tilt, resulting in the evanescence of the in-plane optical anisotropy and the fluidity. In contrast to the classical model of radical polymerization, the time taken for the monolayers to be photopolymerized was inversely proportional to the UV intensity, which is ascribed to the ideal two dimensionality of the reaction field. Because the polymerization degree is quantitatively estimated from the in-plane optical anisotropy of the LC monolayers, the process is traced, from moment to moment, by in situ microscopy observation.

15.
Biochemistry ; 59(28): 2602-2607, 2020 07 21.
Article de Anglais | MEDLINE | ID: mdl-32567852

RÉSUMÉ

The visual pigments of humans contain 11-cis retinal as the chromophore of light perception, and its photoisomerization to the all-trans form initiates visual excitation in our eyes. It is well-known that three isomeric states of retinal (11-cis, all-trans, and 9-cis) are in photoequilibrium at very low temperatures such as 77 K. Here we report the lack of formation of the 9-cis form in monkey blue (MB) at 77 K, as revealed by light-induced difference Fourier transform infrared spectroscopy. This indicates that the chromophore binding pocket of MB does not accommodate the 9-cis form, even though it accommodates the all-trans form by twisting the chromophore. Mutation of the blue-specific tyrosine at position 265 to tryptophan, which is highly conserved in other animal rhodopsins, led to formation of the 9-cis form in MB, suggesting that Y265 is one of the determinants of the unique photochemistry in blue pigments. We also found that 9-cis retinal does not bind to MB opsin, implying that the chromophore binding pocket does not accommodate the 9-cis form at physiological temperature. The unique property of MB is discussed on the basis of the results presented here.


Sujet(s)
Diterpènes/composition chimique , Rétinal/composition chimique , Opsines des bâtonnets/composition chimique , Animaux , Sites de fixation , Bovins , Cellules HEK293 , Haplorhini , Humains , Isomérie , Modèles moléculaires , Pigments rétiniens/composition chimique , Rhodopsine/composition chimique
16.
Sci Rep ; 7(1): 15728, 2017 Nov 16.
Article de Anglais | MEDLINE | ID: mdl-29146932

RÉSUMÉ

Various studies contributed to discover novel mechanisms of central arginine vasopressin (AVP) system responsible for the behaviour albeit endogenous vasopressin activation. We established a novel transgenic rat line which expresses both human muscarinic acetylcholine receptors (hM3Dq), of which ligand is clozapine-N-oxide (CNO), and mCherry fluorescence specifically in AVP neurons. The mCherry neurons that indicate the expression of the hM3Dq gene were observed in the suprachiasmatic (SCN), supraoptic (SON), and paraventricular nuclei (PVN). hM3Dq-mCherry fluorescence was localized mainly in the membrane of the neurons. The mCherry neurons were co-localized with AVP-like immunoreactive (LI) neurons, but not with oxytocin-LI neurons. The induction of Fos, which is the indicator for neuronal activity, was observed in approximately 90% of the AVP-LI neurons in the SON and PVN 90 min after intraperitoneal (i.p.) administration of CNO. Plasma AVP was significantly increased and food intake, water intake, and urine volume were significantly attenuated after i.p. administration of CNO. Although the detailed mechanism has unveiled, we demonstrated, for the first time, that activation of endogenous AVP neurons decreased food intake. This novel transgenic rat line may provide a revolutionary insight into the neuronal mechanism regarding central AVP system responsible for various kind of behaviours.


Sujet(s)
Arginine vasopressine/métabolisme , Consommation alimentaire , Neurones/métabolisme , Animaux , Arginine vasopressine/sang , Clozapine/administration et posologie , Clozapine/pharmacologie , Drogues fabriquées clandestinement/pharmacologie , Consommation de boisson , Fluorescence , Humains , Neurones/effets des médicaments et des substances chimiques , Ocytocine/métabolisme , Noyau paraventriculaire de l'hypothalamus/effets des médicaments et des substances chimiques , Noyau paraventriculaire de l'hypothalamus/métabolisme , Protéines proto-oncogènes c-fos/métabolisme , Rats transgéniques , Rat Wistar , Récepteur muscarinique de type M3/métabolisme , Noyau suprachiasmatique/métabolisme , Urine
17.
Sci Rep ; 7(1): 4904, 2017 07 07.
Article de Anglais | MEDLINE | ID: mdl-28687791

RÉSUMÉ

Protein-bound water molecules are essential for the structure and function of many membrane proteins, including G-protein-coupled receptors (GPCRs). Our prior work focused on studying the primate green- (MG) and red- (MR) sensitive visual pigments using low-temperature Fourier transform infrared (FTIR) spectroscopy, which revealed protein-bound waters in both visual pigments. Although the internal waters are located in the vicinity of both the retinal Schiff base and retinal ß-ionone ring, only the latter showed differences between MG and MR, which suggests their role in color tuning. Here, we report FTIR spectra of primate blue-sensitive pigment (MB) in the entire mid-IR region, which reveal the presence of internal waters that possess unique water vibrational signals that are reminiscent of a water cluster. These vibrational signals of the waters are influenced by mutations at position Glu113 and Trp265 in Rh, which suggest that these waters are situated between these two residues. Because Tyr265 is the key residue for achieving the spectral blue-shift in λmax of MB, we propose that these waters are responsible for the increase in polarity toward the retinal Schiff base, which leads to the localization of the positive charge in the Schiff base and consequently causes the blue-shift of λmax.


Sujet(s)
Pigments rétiniens/composition chimique , Rétinal/composition chimique , Bases de Schiff/composition chimique , Eau/composition chimique , Animaux , Clonage moléculaire , Vision des couleurs/physiologie , Expression des gènes , Vecteurs génétiques/composition chimique , Vecteurs génétiques/métabolisme , Cellules HEK293 , Haplorhini , Humains , Lumière , Mutagenèse dirigée , Mutation , Protéines recombinantes/composition chimique , Protéines recombinantes/génétique , Protéines recombinantes/métabolisme , Pigments rétiniens/génétique , Pigments rétiniens/métabolisme , Rétinal/métabolisme , Bases de Schiff/métabolisme , Spectroscopie infrarouge à transformée de Fourier , Eau/métabolisme
18.
Biochem Biophys Res Commun ; 490(3): 794-799, 2017 08 26.
Article de Anglais | MEDLINE | ID: mdl-28645611

RÉSUMÉ

Cisplatin, known as an anticancer drug, has been widely used; however, diverse disadvantageous side effects, including appetite loss, afflict patients. Nesfatin-1/NucB2, discovered as an anorexic neuropeptide, is broadly expressed in the central nervous system (CNS) and peripheral organ. In the present study, we examined the effects of intraperitoneally (i.p.) administered cisplatin on central nesfatin-1/NucB2. Saline, as control, or cisplatin (6 mg/kg dissolved in saline) was i.p. administered in adult male Wistar rats (180-220 g). Cumulative food intake was remarkably suppressed for at least 24 h and body weight was significantly smaller at 24 h after i.p. administration of cisplatin compared to control group. At 90 min after i.p. administration, they were perfused, followed by carrying out double-immunohistochemistry for Fos and nesfatin-1/NucB2. The percentage of nesfatin-1/NucB2 immunoreactive neurons expressing Fos was marked increased in the hypothalamus and brainstem after i.p. administration of cisplatin. Intracerebroventricularlly administered nesfatin-1/NucB2-antisense resulted in a significant attenuation of decreased food intake for 2 h after i.p. administration of cisplatin compared to nesfatin-1/NucB2-missense treated group. These results suggest that i.p. administration of cisplatin activated, at least in part, nesfatin-1/NucB2 neuron in the CNS and may exert anorexigenic effects in rats.


Sujet(s)
Anorexie/induit chimiquement , Antinéoplasiques/effets indésirables , Protéines de liaison au calcium/métabolisme , Cisplatine/effets indésirables , Protéines de liaison à l'ADN/métabolisme , Consommation alimentaire/effets des médicaments et des substances chimiques , Protéines de tissu nerveux/métabolisme , Neurones/effets des médicaments et des substances chimiques , Prise de poids/effets des médicaments et des substances chimiques , Animaux , Anorexie/métabolisme , Anorexie/anatomopathologie , Antinéoplasiques/administration et posologie , Protéines de liaison au calcium/analyse , Cisplatine/administration et posologie , Protéines de liaison à l'ADN/analyse , Injections péritoneales , Mâle , Protéines de tissu nerveux/analyse , Neurones/métabolisme , Neurones/anatomopathologie , Nucléobindines , Rats , Rat Wistar
19.
Biol Open ; 5(2): 154-60, 2016 Jan 19.
Article de Anglais | MEDLINE | ID: mdl-26787679

RÉSUMÉ

Swimming microalgae show various taxes, such as phototaxis and gravitaxis, which sometimes result in the formation of a cell-rich layer or a patch in a suspension. Despite intensive studies on the effects of shear flow and turbulence on the inhomogeneous distribution of microalgae, the effect of a bubble plume has remained unclear. In this study, we used Chlamydomonas as model microalgae, and investigated the spatial distribution of cells in a cylindrical container with a bubble plume. The results illustrate that cells become inhomogeneously distributed in the suspension due to their motility and photo-responses. A vortical ring distribution was observed below the free surface when the bubble flow rate was sufficiently small. We performed a scaling analysis on the length scale of the vortical ring, which captured the main features of the experimental results. These findings are important in understanding transport phenomena in a microalgae suspension with a bubble plume.

20.
Carbohydr Polym ; 137: 277-286, 2016 Feb 10.
Article de Anglais | MEDLINE | ID: mdl-26686131

RÉSUMÉ

Chitosan-based glycopolymers having multiple ß-lactosides exclusively at their C6-positions were successfully synthesized from partially deacetylated chitin through perfect N-deacetylation/phthaloylation and C6-selective bromination/azidation to afford 6-azide-6-deoxy-N-phthaloyl-chitosan and the subsequent Cu(+)-catalyzed Huisgen cycloadditions using alkyne-terminated ß-lactoside and/or quaternary ammonium modules followed by dephthaloylations. Lectin-affinities of the resultant chitosan-based glycopolymers were assessed through fluorescence titration assays to show their unique sigmoidal binding profiles with amplified binding constants.


Sujet(s)
Chitosane/composition chimique , Lectines/composition chimique , Polymères/composition chimique , Chimie click , Stéréoisomérie
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE