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1.
JSES Int ; 8(3): 500-507, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38707568

RESUMO

Hypothesis/Background: Addressing irreparable subscapularis in conjunction with reverse total shoulder arthroplasty (RTSA) presents challenges. RTSA without subscapularis repair leads to similar clinical results compared to those with a subscapularis repair but with less range of motion in internal rotation (IR). Optimization of IR and anterior stability after RTSA, in the setting of an irreparable subscapularis may be achieved with a pectoralis major (PM) tendon transfer. This study aims to describe a novel surgical technique involving PM transfer in RTSA for irreparable subscapularis and report the initial clinical and radiological outcomes. Methods: This study included 13 patients with an average of 65.5 years (range, 52-82 years). All patients underwent a lateralized RTSA with concurrent PM transfer, associated to an irreparable subscapularis, performed by a single surgeon (PV). Preoperative and postoperative range of motion, including internal rotation 1, internal rotation 2, external rotation 1 (ER1) and forward elevation, were measured. The absolute Constant score, the age and sex-adjusted Constant Murley score, Visual Analog Scale and subjective shoulder value were evaluated by the same surgeon. Standard X-rays, preoperative magnetic resonance imaging, and computed tomography scan were performed for all patients. Results: With an average follow-up of 37 months, the mean Constant score improved from 17.7 preoperatively to 61 postoperative (P < .05). Postoperative clinical outcomes significantly improved across the study group. Mean internal rotation 2 increased from 44.6° to 61.5° (P < .05), while internal rotation 1 improved from 2.6 to 5 (P < .05). The Gerber test yielded positive results for all patients, while the belly press test was negative for eleven patients. Postoperative imaging assessment of the transferred PM tendon transfer showed intact repair, a good cicatrization on the lesser tuberosity with excellent trophicity of the muscle without any fatty infiltration in all patients. Conclusion: PM transfer combined with a lateralized RSTA in cases of irreparable subscapularis leads to improved shoulder range of motion, particularly in IR, increased strength and pain relief.

2.
Artigo em Inglês | MEDLINE | ID: mdl-37866752

RESUMO

BACKGROUND: The use of reverse shoulder arthroplasty (RSA) is becoming increasingly prevalent. However, few studies have been published reporting the long-term outcomes of RSA. This study aims to report the clinical, radiographic, and patient-reported outcomes of the Delta Xtend reverse shoulder prosthesis, performed by a single surgeon and with a minimum follow-up of 10 years. METHODS: All RSA procedures performed between 2005 and 2012 were identified. Patients were contacted and invited for a follow-up visit including clinical assessment, radiographs, and patient-reported outcome measures. Patients with a follow-up of less than 10 years were excluded. The revision-free implant survival was calculated at 10 years. Between 2005 and 2012, 119 procedures in 116 patients meeting inclusion criteria were identified. Of these patients, 35 were deceased before reaching the 10-year follow-up and 23 could not be reached. In total, 63 RSAs could be included in 61 patients (response rate: 75%). The median follow-up was 11.7 years (interquartile range [IQR]: 10.5-13.2). RESULTS: Of the 61 patients, 7 patients underwent a revision after a median of 3 years (IQR: 0.2-9.8) during the total follow-up period. The 10-year implant survival was 94% (95% confidence interval: 84-98). At final follow-up, the median anterior elevation was 135° (IQR: 130°-160°), the median abduction was 120° (IQR: 100°-135°), and the median level reached with internal rotation was L5 (IQR: sacrum-L5). The median Auto-Constant score was 68 (IQR: 53-78), the median Subjective Shoulder Value was 80 (IQR: 70-93), and the median pain score was 0.2/10 (IQR: 0-2). In total, radiographs could be obtained in 25 patients (40%). Scapular notching occurred in 10 patients (40%), which was classified as Sirveaux-Nerot grade IV in 3 patients (12%). Ossification occurred in 10 patients (40%), and stress shielding in 2 patients (8%). Radiolucencies were observed around the humeral component in 24 patients (96%) and around the glenoid component in 13 patients (52%). CONCLUSION: The long-term results of RSA with a Delta Xtend prosthesis are favorable, with long-term improvement in range of motion and patient-reported outcome measures, and a satisfactory implant survival rate. Interestingly, the radiographical analysis showed high prevalence of signs associated with loosening, which did not seem to translate to high complication rates or inferior results.

3.
Front Plant Sci ; 14: 1117572, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36890905

RESUMO

The impact of water deficit on volatile organic compounds (VOCs) responsible for grape aroma remains quite unclear. The aim of this study was to evaluate the effect of different timing and intensity of water deficit on berry VOCs and on their biosynthetic pathways. Fully irrigated control vines were compared with the following treatments: i) two different levels of water deficit from berry pea-size through veraison, ii) one level of water deficit during the lag-phase, and iii) two different levels of water deficit from veraison through harvest. At harvest, total VOC concentrations were higher in berries of water stressed vines from berry pea size through veraison or during the lag phase, whereas post-veraison water deficit determined similar concentrations as control. This pattern was even more pronounced for the glycosylated fraction and was also observed for single compounds, mainly monoterpenes and C13-norisoprenoids. On the other hand, free VOCs were higher in berries from lag phase or post-veraison stressed vines. The significant glycosylated and free VOCs increment measured after the short water stress limited to the lag phase highlight the pivotal role played by this stage in berry aroma compound biosynthesis modulation. The severity of water stress before veraison was also important, since glycosylated VOCs showed a positive correlation with the pre-veraison daily water stress integral. The RNA-seq analysis showed a wide regulation induced by irrigation regimes on terpenes and carotenoids biosynthetic pathways. The terpene synthases and glycosyltransferases as well as genes of the network of transcription factors were upregulated, especially in berries from pre-veraison stressed vines. Since the timing and intensity of water deficit contribute to regulate berry VOCs, irrigation management can be used to achieve high-quality grapes while saving water.

4.
Shoulder Elbow ; 14(6): 657-662, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36479017

RESUMO

Background: Loss of internal rotation remains an issue after reverse total shoulder arthroplasty (RTSA). Our goal is to define the expected functional internal rotation after RTSA using the Activities of Daily Living which require Internal Rotation (ADLIR) score in a homogenous population of patients treated with RTSA. Methods: 35 patients with a minimum follow-up of two years after RTSA were evaluated using the ADLIR and Constant-Murley questionnaires. A correlation between the ADLIR and Constant score was investigated and the internal validity of the ADLIR score used in a RTSA patient population was measured using Cronbach's alpha coefficient. The impact of internal rotation on the total rotational arc of motion was defined. Results: Excellent results were recorded for both the Constant score (79 ± 18) and ADLIR score (88 ± 16). Pearson's correlation coefficient was r = 0,84 (p-value <0,001). The ADLIR score showed a high reliability for all questions. Conclusions: The ADLIR score has proven to be a useful addition in the post-operative evaluation of patients treated with RTSA. Further studies are needed to investigate the evolution of the ADLIR score from pre- to postoperatively in order to determine the clinical and predictive value of this score. Level of evidence: Level IV - Observational study.

5.
Front Plant Sci ; 13: 1040899, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36388597

RESUMO

In this work, we tested the effect of different regulated deficit irrigation (RDI) regimes on berry flavonoid content and its relative biosynthetic pathways. Vines were subjected to six irrigation regimes over two consecutive years: a) full irrigation during the entire irrigation period (FI); b) moderate (RDI-1M) or c) severe (RDI-1S) water deficit between berry pea-size and veraison; d) severe water deficit during the lag-phase (RDI-LS); and e) moderate (RDI-2M) or f) severe (RDI-2S) water deficit from veraison through harvest. Berries from both RDI-1 treatments showed the highest accumulation of anthocyanins, upregulating the expression of many genes of the flavonoid pathway since the beginning of veraison until harvest, far after the water deficit was released. Although to a lesser degree than RDI-1, both post-veraison water deficit treatments increased anthocyanin concentration, particularly those of the tri-substituted forms, overexpressing the F3'5'H hydroxylases. The moderate deficit irrigation treatments enhanced anthocyanin accumulation with respect to the severe ones regardless of the period when they were applied (pre- or post-veraison). The water deficit imposed during the lag-phase downregulated many genes throughout the flavonoid pathway, showing a slight reduction in anthocyanin accumulation. The measurements of cluster temperature and light exposure highlighted that under deficit irrigation conditions, the effects induced by water stress prevailed over that of light and temperature in regulating anthocyanin biosynthesis. Flavonol concentration was higher in RDI-1S berries due to the upregulation of the flavonol synthases and the flavonol-3-O-glycosyltransferases. In this case, the higher cluster light exposure induced by water deficit in RDI-1S berries had a major role in flavonol accumulation. We conclude that the timing and intensity of water stress strongly regulate the berry flavonoid accumulation and that proper management of deficit irrigation can modulate the phenylpropanoid and flavonoid pathways.

6.
Int Orthop ; 46(10): 2273-2281, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35922519

RESUMO

PURPOSE: The objective of this study was to evaluate the clinical and radiological outcomes of reverse shoulder arthroplasty (RSA) associated with two techniques: L'Episcopo procedure (combined teres major and latissimus dorsi transfer) and modified L'Episcopo procedure (isolated latissimus dorsi transfer). METHODS: A retrospective review of 36 RSAs (mean age 69.8 years; SD 8.9) associated with either L'Episcopo procedure (Group 1, 21 cases) or modified L'Episcopo procedure (Group 2, 15 cases) was performed between 2007 and 2020. Clinical outcome measures consisted of range of motion (ROM), SSV, VAS, and Constant-Murley scores. These scores were compared between the two groups. Radiographs were assessed for transfer site bony lesions. RESULTS: With a mean follow-up of 40.8 months (6-98; SD 28.8), no significant differences were revealed in the clinical outcomes: Constant score, SSV, VAS, ROM. The entire study group demonstrated a significant improvement in post-operative functional outcome scores and ROM parameters compared to their pre-operative state, IR measures being the only exception (p = 0.26). Radiographs demonstrated transfer site bony lesions in 60% of the patients (18/30). Three complications (8.3%) were noted in the study. CONCLUSION: At the short-term follow-up, RSA combined with either latissimus dorsi (LD) transfer in isolation or in association with teres major proved to be equally effective in restoring external rotation in the settings of an irreparable postero-superior cuff tear treated with RSA. Although the LD transfer group displayed a tendency towards superior ROM, this was not supported statistically. Post-operative radiographs confirmed the presence of bony lesions at the transfer fixation sites in both groups of patients (52% vs. 72%).


Assuntos
Artroplastia do Ombro , Lesões do Manguito Rotador , Articulação do Ombro , Músculos Superficiais do Dorso , Idoso , Artroplastia/métodos , Artroplastia do Ombro/efeitos adversos , Humanos , Amplitude de Movimento Articular , Lesões do Manguito Rotador/cirurgia , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/cirurgia , Músculos Superficiais do Dorso/cirurgia , Transferência Tendinosa/métodos , Resultado do Tratamento
7.
Orthop Traumatol Surg Res ; 108(3): 103263, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35248792

RESUMO

BACKGROUND: Reverse total shoulder arthroplasty (RSA) associated with modified L'Episcopo (isolated LD) or L'Episcopo (combined TM and LD) procedures had been confirmed to effectively overcome the expected external rotation deficit in patient with postero-superior massive cuff tear and teres minor deficiency. The objective of this study was to evaluate the radiological bony lesions of the lateral proximal humerus following RSA combined with tendon transfer, and to determine whether these bony lesions affect the clinical outcome. MATERIAL AND METHODS: A retrospective review of 24 RSAs (mean age 68.71 years, range 52-83) associated with modified L'Episcopo procedure (9) and L'Episcopo procedure (15) was performed. X-rays were assessed for lateral cortex lesions and were categorized into either intact, irregular or complete lytic appearances. In addition, signs of stem loosening were assessed. Clinical outcome measures included range of motion, SSV, VAS, and Constant-Murley scores. RESULTS: With a mean follow-up of 44.71 months (12-97; SD 27.42), eight (33.3%) patients demonstrated intact lateral cortex, eight (33.3%) irregular and eight (33.3%) lytic lesions. 40% of cemented stems demonstrated a deformed cortex compared to 74% of cementless stems. Radiolucent lines were detected in one cemented stem (p=0.046). GT resorption (p=0.147), condensations lines (p=0.449) and spot weld (p=0.342), appeared exclusively in non-cemented stem. Postoperatively all patients (24) demonstrated significant improvements in all clinical and functional parameters. A comparison between patient with (Group 2, 16 patients) and without bony lesions (Group 1, 8 patients) revealed no significant differences in functional scores and range of motion: Constant (p=0,61), VAS (p=0,61), SSV (p=0,66) and external rotation (p=0,34). CONCLUSION: At short-term follow-up, RSA combined with L'Episcopo or modified l'Episcopo procedure resulted in high incidence (67%) of lateral proximal humerus lesions. Radiolucent lines were noted in cemented stems whereas, signs of stress shielding and GT resorption appeared in non-cemented stems. Yet, no case of humeral loosening was detected and these lesions did not seem to affect the clinical outcome. The use of cemented straight standard-length humeral stems should be positively considered in RSA associated with LD\TM tendon transfer. LEVEL OF EVIDENCE: IV; retrospective study.


Assuntos
Artroplastia do Ombro , Articulação do Ombro , Idoso , Idoso de 80 Anos ou mais , Artroplastia/métodos , Doenças das Cartilagens/cirurgia , Humanos , Úmero/diagnóstico por imagem , Úmero/cirurgia , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Estudos Retrospectivos , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/cirurgia , Transferência Tendinosa/métodos , Resultado do Tratamento
8.
Front Mol Neurosci ; 15: 1054449, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36710929

RESUMO

Retinal rods evolved to be able to detect single photons. Despite their exquisite sensitivity, rods operate over many log units of light intensity. Several processes inside photoreceptor cells make this incredible light adaptation possible. Here, we added to our previously developed, fully space resolved biophysical model of rod phototransduction, some of the mechanisms that play significant roles in shaping the rod response under high illumination levels: the function of RGS9 in shutting off G protein transducin, and calcium dependences of the phosphorylation rates of activated rhodopsin, of the binding of cGMP to the light-regulated ion channel, and of two membrane guanylate cyclase activities. A well stirred version of this model captured the responses to bright, saturating flashes in WT and mutant mouse rods and was used to explain "Pepperberg plots," that graph the time during which the response is saturated against the natural logarithm of flash strength for bright flashes. At the lower end of the range, saturation time increases linearly with the natural logarithm of flash strength. The slope of the relation (τD) is dictated by the time constant of the rate-limiting (slowest) step in the shutoff of the phototransduction cascade, which is the hydrolysis of GTP by transducin. We characterized mathematically the X-intercept ( Φ o ) which is the number of photoisomerizations that just saturates the rod response. It has been observed that for flash strengths exceeding a few thousand photoisomerizations, the curves depart from linearity. Modeling showed that the "upward bend" for very bright flash intensities could be explained by the dynamics of RGS9 complex and further predicted that there would be a plateau at flash strengths giving rise to more than ~107 photoisomerizations due to activation of all available PDE. The model accurately described alterations in saturation behavior of mutant murine rods resulting from transgenic perturbations of the cascade targeting membrane guanylate cyclase activity, and expression levels of GRK, RGS9, and PDE. Experimental results from rods expressing a mutant light-regulated channel purported to lack calmodulin regulation deviated from model predictions, suggesting that there were other factors at play.

9.
Front Mol Neurosci ; 15: 1050545, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36590910

RESUMO

Accurate photon counting requires that rods generate highly amplified, reproducible single photon responses (SPRs). The SPR is generated within the rod outer segment (ROS), a multilayered structure built from membranous disks that house rhodopsin. Photoisomerization of rhodopsin at the disk rim causes a local depletion of cGMP that closes ion channels in the plasmalemma located nearby with relative rapidity. In contrast, a photoisomerization at the disk center, distant from the plasmalemma, has a delayed impact on the ion channels due to the time required for cGMP redistribution. Radial differences should be greatest in large diameter rods. By affecting membrane guanylate cyclase activity, bicarbonate could impact spatial inhomogeneity in cGMP content. It was previously known that in the absence of bicarbonate, SPRs are larger and faster at the base of a toad ROS (where the ROS attaches to the rest of the cell) than at the distal tip. Given that bicarbonate enters the ROS at the base and diffuses to the tip and that it expedites flash response recovery, there should be an axial concentration gradient for bicarbonate that would accentuate the base-to-tip SPR differences. Seeking to understand how ROS geometry and bicarbonate affect SPR variability, we used mathematical modeling and made electrophysiological recordings of single rods. Modeling predicted and our experiments confirmed minor radial SPR variability in large diameter, salamander rods that was essentially unchanged by bicarbonate. SPRs elicited at the base and tip of salamander rods were similar in the absence of bicarbonate, but when treated with 30 mM bicarbonate, SPRs at the base became slightly faster than those at the tip, verifying the existence of an axial gradient for bicarbonate. The differences were small and unlikely to undermine visual signaling. However, in toad rods with longer ROSs, bicarbonate somehow suppressed the substantial, axial SPR variability that is naturally present in the absence of bicarbonate. Modeling suggested that the axial gradient of bicarbonate might dampen the primary phototransduction cascade at the base of the ROS. This novel effect of bicarbonate solves a mystery as to how toad vision is able to function effectively in extremely dim light.

10.
Front Psychol ; 12: 762213, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858288

RESUMO

This contribute investigates how Emergency Remote Education (ERE) impacted families during the spring 2020 Covid-19 lockdown, and in particular, the extent to which the impact of ERE on families, measured in terms of space and equipment sharing, moderates the effect of student and family characteristics on students' engagement. The study derived from the administration of an online survey to 19,527 families with children attending schools, from nursery to upper secondary grade. The total number of student records collected amounted to 31,805, since parents had to provide data for each school-age child in the family. The survey contains 58 questions, divided into three sections, with the first two sections designed to get a reading at family level and the third section to gather data for each school-age child in the family. After verifying the validity of the engagement construct through confirmatory factor analysis, two structural equation models were used to analyze the students' engagement. The main findings reveal how the impact of the ERE on the families has had a significant role in predicting students' level of engagement observed by parents with respect to different predictor variables. Finally, we argue that it is necessary to follow a holistic approach to observe the challenges imposed by the switch of the process of deferring teaching from presence to distance, imposed by the pandemic emergency on families. In fact, a holistic approach can promote student engagement and prevent the onset of cognitive-behavioral and affective problems linked to disengagement in ERE.

11.
Antioxidants (Basel) ; 10(12)2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34942968

RESUMO

Fig trees are often grown in areas affected by salinity problems. We investigated changes in the concentrations of 15 phenolic compounds and mineral elements (Mg, Ca, K, Zn, Cu, Mn, Mo, Fe, Na) in fruits of fig plants (Ficus carica L. cv. Dottato) subjected to irrigation with saline water (100 mM of NaCl) for 28 days. We used UHPLC-MS/MS techniques to determine chlorogenic acid, tiliroside, catechin, epicatechin (ECTC), p-coumaric acid, trans-ferulic acid, phloridzin, phloretine, quercetagetin 7-O-glucoside, rutin, quercetin 3-O-glucoside, kaempferol 3-O-rutinoside, kaempferol 7-O-glucoside, kaempferol 3-O-glucoside, and quercetin. There was a steep gradient of Na+ concentrations between the root and the canopy of salinized plants, but leaf Na+ was similar in control and salt-treated plants. Quercetin, ECTC, and chlorogenic acid were the most abundant phenolic compounds in fig fruits. Salinity increased total phenols by 5.6%, but this increase was significant only for ECTC. Salt stress significantly increased Zn and Mg concentration in the fruit. Leaf levels of K, Mg, Ca, and Mn were similar in control and salinized plants. Moderate salt stress appears to improve fig fruit quality because of its positive effect on nutrients and antioxidant compounds such as epicatechin.

12.
PLoS One ; 16(10): e0258721, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34710119

RESUMO

In daylight, cone photoreceptors in the retina are responsible for the bulk of visual perception, yet compared to rods, far less is known quantitatively about their biochemistry. This is partly because it is hard to isolate and purify cone proteins. The issue is also complicated by the synergistic interaction of these parameters in producing systems biology outputs, such as photoresponse. Using a 3-D resolved, finite element model of cone outer segments, here we conducted a study of parameter significance using global sensitivity analysis, by Sobol indices, which was contextualized within the uncertainty surrounding these parameters in the available literature. The analysis showed that a subset of the parameters influencing the circulating dark current, such as the turnover rate of cGMP in the dark, may be most influential for variance with experimental flash response, while the shut-off rates of photoexcited rhodopsin and phosphodiesterase also exerted sizable effect. The activation rate of transducin by rhodopsin and the light-induced hydrolysis rate of cGMP exerted measurable effects as well but were estimated as relatively less significant. The results of this study depend on experimental ranges currently described in the literature and should be revised as these become better established. To that end, these findings may be used to prioritize parameters for measurement in future investigations.


Assuntos
GMP Cíclico/metabolismo , Transdução de Sinal Luminoso , Luz , Células Fotorreceptoras Retinianas Cones/fisiologia , Transducina/fisiologia , Visão Ocular/fisiologia , Animais , Camundongos , Camundongos Knockout
13.
Plants (Basel) ; 10(9)2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34579394

RESUMO

Fig trees (Ficus carica L.) are commonly grown in the Mediterranean area, where salinity is an increasing problem in coastal areas. Young, fruiting plants of cv. Dottato were subjected to moderate salt stress (100 mM NaCl added to irrigation water) for 48 days before fruit sampling. To clarify the effect of salinity stress, we investigated changes in the transcription of the main sugar metabolism-related genes involved in the synthesis, accumulation and transport of soluble carbohydrates in ripe fruits by quantitative real-time PCR as well as the content of soluble sugars by quantitative 1H nuclear magnetic resonance spectroscopy. A general increase in the transcript levels of genes involved in the transport of soluble carbohydrates was observed. Alkaline-neutral and Acid Invertases transcripts, related to the synthesis of glucose and fructose, were up-regulated in ripe fruits of NaCl-stressed plants without a change in the content of D-glucose and D-fructose. The increases in sucrose and D-sorbitol contents were likely the result of the up-regulation of the transcription of Sucrose-Synthase- and Sorbitol-Dehydrogenase-encoding genes.

14.
PLoS One ; 15(10): e0240527, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33052986

RESUMO

Retinal rods function as accurate photon counters to provide for vision under very dim light. To do so, rods must generate highly amplified, reproducible responses to single photons, yet outer segment architecture and randomness in the location of rhodopsin photoisomerization on the surface of an internal disk introduce variability to the rising phase of the photon response. Soon after a photoisomerization at a disk rim, depletion of cGMP near the plasma membrane closes ion channels and hyperpolarizes the rod. But with a photoisomerization in the center of a disk, local depletion of cGMP is distant from the channels in the plasma membrane. Thus, channel closure is delayed by the time required for the reduction of cGMP concentration to reach the plasma membrane. Moreover, the local fall in cGMP dissipates over a larger volume before affecting the channels, so response amplitude is reduced. This source of variability increases with disk radius. Using a fully space-resolved biophysical model of rod phototransduction, we quantified the variability attributable to randomness in the location of photoisomerization as a function of disk structure. In mouse rods that have small disks bearing a single incisure, this variability was negligible in the absence of the incisure. Variability was increased slightly by the incisure, but randomness in the shutoff of rhodopsin emerged as the main source of single photon response variability at all but the earliest times. Variability arising from randomness in the transverse location of photoisomerization increased in magnitude and persisted over a longer period in the photon response of large salamander rods. A symmetric arrangement of multiple incisures in the disks of salamander rods greatly reduced this variability during the rising phase, but the incisures had the opposite effect on variability arising from randomness in rhodopsin shutoff at later times.


Assuntos
Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Rodopsina/metabolismo , Visão Ocular/fisiologia , Animais , Isomerismo , Camundongos , Modelos Teóricos , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Urodelos
16.
Sarcoma ; 2020: 5289547, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33488268

RESUMO

Limb salvage surgery is now the preferred procedure for bone tumor surgery. To decrease the risk of local recurrence, it is crucial to obtain adequate resection margins. The obtained margins must be evaluated postoperatively because they influence what treatment is given subsequently when margins are not adequate (e.g., surgical revision and radiotherapy). The study aims to evaluate margin assessment of tumor specimen by MRI compared to conventional histology (to establish the viability of using MRI) and assess the accuracy of a patient-specific instrument when narrow margins were aimed. The resection margins in 12 consecutive patients that were operated on for bone tumor resection were prospectively analyzed using three methods: MRI of the resection specimen, macroscopic evaluation of specimen slices, and microscopic pathological evaluation. The assessments were qualitative (R0, R1, and R2) and quantitative (distance in mm). MRI, macroscopic, and microscopic margins generated similar results for both the qualitative (all resections were R0) and quantitative assessments. The median error in safe margins was 2 mm with a surgical guide (PSI) and 5 mm without a surgical guide. Local recurrences were not detected after a mean follow-up period of 3.7 years (range, 2.1-5 years); however, four patients died during the study. In conclusion, MRI is a valuable tool for assessing safe margins. When specimens are not available for pathological assessment (e.g., extracorporeally irradiated autograft or autoclaved autograft), MRI could be used to evaluate margins. In particular, when tumor volume is high, MRI could also help to focus the pathological examination on areas of concern.

17.
Acta Orthop Belg ; 86(4): 599-605, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33861905

RESUMO

The purpose of this study was to evaluate the morphologic evolution of the shelf gap, acetabulum and femoral head after shelf acetabuloplasty in patients affected by Perthes disease. 54 patients operated for Perthes disease with shelf acetabuloplasty were retrospectively reviewed regarding the radiographic results. Three pelvic antero-posterior radiographs have been studied for each patient, one at 2 postoperative months, one at 1 postoperative year and one at the latest clinical follow up (mean 76 postoperative months). The shelf gap decreased from 108% at 2 months to 104% at the last follow-up (p<0.001). There was an increase of the total acetabular depth to 168% by the presence of the shelf graft (p<0.001). The acetabular index of the operated side related to the contralateral side was 68% at 2 months due to the effect of the graft (p<0.001). The migration index of the shelf side was in mean -24% at 2 months and -3% at last follow- up (p<0.001). According to the Stulberg classification, there were 9 type 1 (17%), 20 type 2 (37%), 19 type 3 (35%), 5 type 4 (9%) and 1 type 5 (2%). A progressive remodeling with shelf gap reduction was occurring during the following months after the surgery. An increase of the total acetabular depth and a decrease of the migration index without a lateral overgrowth of the paleo-acetabulum was observed. Shelf acetabuloplasty is a good procedure to prevent early osteoarthritis by a better femoral head coverage.


Assuntos
Acetabuloplastia , Doença de Legg-Calve-Perthes , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/cirurgia , Seguimentos , Humanos , Doença de Legg-Calve-Perthes/diagnóstico por imagem , Doença de Legg-Calve-Perthes/cirurgia , Estudos Retrospectivos
18.
PLoS One ; 14(12): e0225948, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31805112

RESUMO

The single photon response (SPR) in vertebrate photoreceptors is inherently variable due to several stochastic events in the phototransduction cascade, the main one being the shutoff of photoactivated rhodopsin. Deactivation is driven by a random number of steps, each of random duration with final quenching occurring after a random delay. Nevertheless, variability of the SPR is relatively low, making the signal highly reliable. Several biophysical and mathematical mechanisms contributing to variability suppression have been examined by the authors. Here we investigate the contribution of local depletion of cGMP by PDE*, the non linear dependence of the photocurrent on cGMP, Ca2+ feedback by making use of a fully space resolved (FSR) mathematical model, applied to two species (mouse and salamander), by varying the cGMP diffusion rate severalfold and rod outer segment diameter by an order of magnitude, and by introducing new, more refined, and time dependent variability functionals. Globally well stirred (GWS) models, and to a lesser extent transversally well stirred models (TWS), underestimate the role of nonlinearities and local cGMP depletion in quenching the variability of the circulating current with respect to fully space resolved models (FSR). These distortions minimize the true extent to which SPR is stabilized by locality in cGMP depletion, nonlinear effects linking cGMP to current, and Ca2+ feedback arising from the physical separation of E* from the ion channels located on the outer shell, and the diffusion of these second messengers in the cytoplasm.


Assuntos
Cálcio/metabolismo , GMP Cíclico/metabolismo , Modelos Biológicos , Fótons , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Transdução de Sinais , Algoritmos , Animais , Biomarcadores , Camundongos , Segmento Externo da Célula Bastonete/fisiologia
19.
PLoS One ; 14(7): e0219848, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31344066

RESUMO

Mammals have two types of photoreceptors, rods and cones. While rods are exceptionally sensitive and mediate vision at very low illumination levels, cones operate in daylight and are responsible for the bulk of visual perception in most diurnal animals, including humans. Yet the mechanisms of phototransduction in cones is understudied, largely due to unavailability of pure cone outer segment (COS) preparations. Here we present a novel mathematical model of cone phototransduction that explicitly takes into account complex cone geometry and its multiple physical scales, faithfully reproduces features of the cone response, and is orders of magnitude more efficient than the standard 3D diffusion model. This is accomplished through the mathematical techniques of homogenization and concentrated capacity. The homogenized model is then computationally implemented by finite element method. This homogenized model permits one to analyze the effects of COS geometry on visual transduction and lends itself to performing large numbers of numerical trials, as required for parameter analysis and the stochasticity of rod and cone signal transduction. Agreement between the nonhomogenized, (i.e., standard 3D), and homogenized diffusion models is reported along with their simulation times and memory costs. Virtual expression of rod biochemistry on cone morphology is also presented for understanding some of the characteristic differences between rods and cones. These simulations evidence that 3D cone morphology and ion channel localization contribute to biphasic flash response, i.e undershoot. The 3D nonhomogenized and homogenized models are contrasted with more traditional and coarser well-stirred and 1D longitudinal diffusion models. The latter are single-scale and do not explicitly account for the multi-scale geometry of the COS, unlike the 3D homogenized model. We show that simpler models exaggerate the magnitude of the current suppression, yield accelerated time to peak, and do not predict the local concentration of cGMP at the ionic channels.


Assuntos
Transdução de Sinal Luminoso , Células Fotorreceptoras Retinianas Cones/metabolismo , Animais , Análise de Elementos Finitos , Modelos Teóricos , Análise Espaço-Temporal
20.
Sci Rep ; 9(1): 2561, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30796285

RESUMO

Although Ficus carica L. (fig) is one of the most resistant fruit tree species to salinity, no comprehensive studies are currently available on its molecular responses to salinity. Here we report a transcriptome analysis of F. carica cv. Dottato exposed to 100 mM sodium chloride for 7 weeks, where RNA-seq analysis was performed on leaf samples at 24 and 48 days after the beginning of salinization; a genome-derived fig transcriptome was used as a reference. At day 24, 224 transcripts were significantly up-regulated and 585 were down-regulated, while at day 48, 409 genes were activated and 285 genes were repressed. Relatively small transcriptome changes were observed after 24 days of salt treatment, showing that fig plants initially tolerate salt stress. However, after an early down-regulation of some cell functions, major transcriptome changes were observed after 48 days of salinity. Seven weeks of 100 mM NaCl dramatically changed the repertoire of expressed genes, leading to activation or reactivation of many cell functions. We also identified salt-regulated genes, some of which had not been previously reported to be involved in plant salinity responses. These genes could be potential targets for the selection of favourable genotypes, through breeding or biotechnology, to improve salt tolerance in fig or other crops.


Assuntos
Ficus , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/fisiologia , Tolerância ao Sal/fisiologia , Ficus/genética , Ficus/metabolismo
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