ATHANASIOS CHATZISOTIRIOU | Aristotle University of Thessaloniki (original) (raw)

Papers by ATHANASIOS CHATZISOTIRIOU

Brain and Spine, Dec 31, 2022

Frontiers in Psychiatry

BackgroundFunctional magnetic resonance imaging (fMRI) is a valuable tool for the presurgical eva... more BackgroundFunctional magnetic resonance imaging (fMRI) is a valuable tool for the presurgical evaluation of patients undergoing neurosurgeries. Although many pre-processing steps have been modified according to advances in recent years, statistical analysis has remained largely the same since the first days of fMRI. In this study, we examined the ability of Independent Component Analysis (ICA) to separate the activation of a language task in fMRI, and we compared it with the results of the General Lineal Model (GLM).MethodsSixty patients undergoing evaluation for brain surgery due to various brain lesions and/or epilepsy and 20 control subjects completed an fMRI language mapping protocol that included three tasks, resulting in 259 fMRI scans. Depending on brain lesion characteristics, patients were allocated to (1) static/chronic not-expanding lesions (Group 1) and (2) progressive/expanding lesions (Group 2). GLM and ICA statistical maps were evaluated by fMRI experts to assess the ...

Journal of experimental orthopaedics, 2024

BMC Cancer, Jan 3, 2012

Background: In this study several tumor-related volumes were assessed by means of a computer-base... more Background: In this study several tumor-related volumes were assessed by means of a computer-based application and a survival analysis was conducted to evaluate the prognostic significance of pre-and postoperative volumetric data in patients harboring glioblastomas. In addition, MGMT (O 6-methylguanine methyltransferase) related parameters were compared with those of volumetry in order to observe possible relevance of this molecule in tumor development. Methods: We prospectively analyzed 65 patients suffering from glioblastoma (GBM) who underwent radiotherapy with concomitant adjuvant temozolomide. For the purpose of volumetry T1 and T2-weighted magnetic resonance (MR) sequences were used, acquired both pre-and postoperatively (pre-radiochemotherapy). The volumes measured on preoperative MR images were necrosis, enhancing tumor and edema (including the tumor) and on postoperative ones, net-enhancing tumor. Age, sex, performance status (PS) and type of operation were also included in the multivariate analysis. MGMT was assessed for promoter methylation with Multiplex Ligationdependent Probe Amplification (MLPA), for RNA expression with real time PCR, and for protein expression with immunohistochemistry in a total of 44 cases with available histologic material. Results: In the multivariate analysis a negative impact was shown for pre-radiochemotherapy net-enhancing tumor on the overall survival (OS) (p = 0.023) and for preoperative necrosis on progression-free survival (PFS) (p = 0.030). Furthermore, the multivariate analysis confirmed the importance of PS in PFS and OS of patients. MGMT promoter methylation was observed in 13/23 (43.5%) evaluable tumors; complete methylation was observed in 3/13 methylated tumors only. High rate of MGMT protein positivity (> 20% positive neoplastic nuclei) was inversely associated with pre-operative tumor necrosis (p = 0.021). Conclusions: Our findings implicate that volumetric parameters may have a significant role in the prognosis of GBM patients. Furthermore, volumetry could help not only to improve the prediction of outcome but also the outcome itself by identifying patients at high risk of treatment failure and, thus, seek alternative treatment for these patients. In this small series, MGMT protein was associated with less aggressive tumor characteristics.

Brain Injury, Apr 27, 2022

The Spine Journal, Oct 1, 2015

BACKGROUND CONTEXT: Total disc replacement (TDR) is widely used as alternative treatment to fusio... more BACKGROUND CONTEXT: Total disc replacement (TDR) is widely used as alternative treatment to fusion for symptomatic cervical disc degenerative diseases. Its advantages (ie, functional improvement, preservation of motion and possibly protection of the adjacent segment) are supported by literature data. The influence of the size of prosthesis on surgical outcomes has been less studied and we could not find any data on its correlation with preoperative disc height. PURPOSE: The aim of current analysis is to evaluate the relationship between surgery outcomes assessed two years postoperatively, and preoperative disc height (PDH)/implant height (BCH) ratio, in patients treated by TDR with a semi constrained prosthesis (BAGUERAÒC, Spineart Inc, Switzerland), using a multicentric prospective database. STUDY DESIGN/SETTING: An independent retrospective analysis of clinical and radiographic data was conducted for 99 patients treated with cervical arthroplasty with a two-year follow-up. PATIENT SAMPLE: We included 99 patients (46 males, 53 females), age mean 43.2 (29 to 70) years at surgery time, all treated at 1 to 3 levels. Overall, 123 prosthesis (5, 6, 7 mm height) were implanted: 70, 49, 4 %, respectively. OUTCOME MEASURES: Pre-and postoperatively radiographic data were extracted by an independent evaluator from dynamic lateral radiographs: disc height, ROM (segmental, overall and at the upper level), segmental and overall lordosis. Self-reported questionnaires (VAS, NDI, SF-36) were used for clinical assessment. METHODS: Implant size effect and relationship between PDH/BCH ratio and clinical and radiographic parameters, assessed 2 years after surgery, were respectively analysed. RESULTS: We observed highest mean segmental ROM (8.8) with a 5mm BCH, but better NDI, VAS and SF-36 scores with 6 mm BCH. The PDH/BCH ratio mean was 0.6 (0.5 to 1.5): 74.3% less than 0.9, 17.7% between 0.9-1.1, 8% greater than 1.1. It was significantly correlated (-0.34, p!0.01) with overall ROM, uncorrelated with segmental ROM, lordosis angles and clinical outcomes. Higher correlation (-0.59, p50.04) with overall ROM was observed for PDH/BCH ratio between 0.9-1.1. The PDH/BCH ! 0.9 was associated with lowest NDI and VAS Neck and PDH/BCH O 1.1 with lowest VAS Arm. CONCLUSIONS: Analysed data further demonstrate the clinical benefits of TDR. Despite the lack of correlation with clinical outcomes, better results were observed with small (þ10%) difference between implant size and preoperative disc height. The surgeon may have to choose the implant in order to open the disc height even if this may reduce mobility.

Muscle & Nerve, Nov 22, 2013

Introduction: Quantitative descriptions of fiber type organization in hind limb muscles are incom... more Introduction: Quantitative descriptions of fiber type organization in hind limb muscles are incomplete or rare. Methods: Fiber morphometrics for both rat tibialis anterior (TA) muscles were measured in 3 dimensions. Results: Slow oxidative fiber area and perimeter varied in all zones. Fast oxidative glycolytic fibers (FOG) were predominant in the mediolateral and posterior zones, and fast glycolytic fibers (FG) predominated in the anterior zone. The mean area of FOG and succinate dehydrogenase intermediate fibers was lowest in the anterior zone. Mean area of FG was highest in the proximal and distal parts of the muscle. The area and perimeter of fast fibers differed significantly between the right and left limbs in the medial zone. In the middle and lateral zones, they differed at the proximal and distal parts. Conclusions: This detailed analysis in a high resolution, 3-dimensional map provides an essential tool for understanding the structure and function of TA muscles.

BMC Physiology, May 2, 2012

Background: It is well known that axotomy in the neonatal period causes massive loss of motoneuro... more Background: It is well known that axotomy in the neonatal period causes massive loss of motoneurons, which is reflected in the reduction of the number of motor units and the alteration in muscle properties. This type of neuronal death is attributed to the excessive activation of the ionotropic glutamate receptors (glutamate excitotoxicity). In the present study we investigated the effect of the NMDA antagonist DAP5 [D-2-amino-5phosphonopentanoic acid] in systemic administration, on muscle properties and on behavioural aspects following peripheral nerve injury. Methods: Wistar rats were subjected to sciatic nerve crush on the second postnatal day. Four experimental groups were included in this study: a) controls (injection of 0.9% NaCl solution) b) crush c) DAP5 treated and d) crush and DAP5 treated. Animals were examined with isometric tension recordings of the fast extensor digitorum longus and the slow soleus muscles, as well as with locomotor tests at four time points, at P14, P21, P28 and adulthood (2 months). Results: 1. Administration of DAP5 alone provoked no apparent adverse effects. 2. In all age groups, animals with crush developed significantly less tension than the controls in both muscles and had a worse performance in locomotor tests (p < 0.01). Crush animals injected with DAP5 were definitely improved as their tension recordings and their locomotor behaviour were significantly improved compared to axotomized ones (p < 0.01). 3. The time course of soleus contraction was not altered by axotomy and the muscle remained slow-contracting in all developmental stages in all experimental groups. EDL, on the other hand, became slower after the crush (p < 0.05). DAP5 administration restored the contraction velocity, even up to the level of control animals 4. Following crush, EDL becomes fatigue resistant after P21 (p < 0.01). Soleus, on the other hand, becomes less fatigue resistant. DAP5 restored the profile in both muscles. Conclusions: Our results confirm that contractile properties and locomotor behaviour of animals are severely affected by axotomy, with a differential impact on fast contracting muscles. Administration of DAP5 reverses these devastating effects, without any observable side-effects. This agent could possibly show a therapeutic potential in other models of excitotoxic injury as well.

International Journal of Molecular Sciences, Dec 19, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Journal of Research and Practice on the Musculoskeletal System, Mar 1, 2018

The Systemic Inflammatory Response Syndrome (SIRS) represents the generalized response of the hos... more The Systemic Inflammatory Response Syndrome (SIRS) represents the generalized response of the host to a variety of significant clinical insults, such as infection and trauma. There are specific criteria in the definition, such as: a) hyperor hypothermia, b) heart rate >90/min, c) respirations >20/ minute or PaCO2 <32 mmHg and d) WBC >12,000/mm 3 or <4,000/mm 3 or >10% immature form, with ≥2 of these criteria being necessary. Trauma is one of the more common causes of mortality worldwide. Death is the result of a chain of events starting with the "first hit", which includes severe organ trauma, hypovolemia, hypoxemia or head injury among others. These can lead to the activation of the immune system and the initial inflammatory immune response after trauma can lead to SIRS. If more insults follow, they become the "second hit", which can include infection, ischemia/reperfusion or surgical operations, then the inflammatory response is augmented, together with the mortality of the patient. Musculoskeletal injury through the activation of SIRS can lead to multi-organ failure with the loss of organ systems that were not directly involved by the initial trauma. The result is the activation of various parts/subsets of the immune system, including the neuroendocrine system, and the involvement of hormones or molecules such as ACTH, catecholamines, corticosteroids, cytokines and chemokines. The goal of this presentation is to stress the fact the musculoskeletal trauma is not an isolated injury, as it can lead to the activation of a mechanism meant to protect the organism; however, if it goes "unchecked" then it can easily lead to death.

Developmental Brain Research, Jun 1, 2005

The purpose of this study was to elucidate the effect of deafferentation on spinal motoneurons. W... more The purpose of this study was to elucidate the effect of deafferentation on spinal motoneurons. We studied the effects of spinal cord transection and/or dorsal rhizotomy upon the contractile properties of EDL and soleus muscle, as well as on the number of motoneurons corresponding to these muscles. Neonatal Wistar rats were randomly divided into four groups in which spinal midthoracic section (T8-T10), unilateral dorsal lumbar rhizotomy (L3-S2) or both procedures were performed on the second postnatal day (PND2). Another group served as unoperated control. At 2 months of age, the animals were evaluated for the contractile properties of a fast (EDL) and a slow (soleus) muscle. Isometric tension recordings were elicited by way of sciatic nerve branches stimulation. In addition, the incremental method was applied for the determination of the number of motor units supplying the two muscles, which was also verified by using the horseradish peroxidase (HRP) method of reverse labeling of motoneurons. Muscle alterations were confirmed by the usual biochemical staining. Our results, in agreement with the data from other researchers, show that significant muscle atrophy takes place after all experimental procedures. Additionally, spinal cord section alters the development of the dynamic properties of soleus muscle, which attains a fast profile. Following transection, the number of motor units remained unaltered, while rhizotomy affected only the soleus by reducing its motor units. The combined procedure affected both muscles, indicating that adequate synaptic input is essential for motoneuron survival.

It has been shown in the rat, that during the first five postnatal days, motoneurons are particul... more It has been shown in the rat, that during the first five postnatal days, motoneurons are particularly vulnerable to excitotoxic cell death and glutamate receptors play a significant role in this time-dependent process. Various categories of glutamate blockers (MK-801, Mg, PNQX, DAP-5) have various actions on the respective receptors. Furthermore, the different response between mature and immature motoneurons following injury is attributed to the quantity of glutamate receptors on the cell membrane. The effect of these substances on the recovery of fast and slow muscles after sciatic nerve crush, at critical developmental stages, shows a variable but impressive reversal of the devastating effects on rat muscle properties, which is different between fast and slow muscles. In addition, blocking of NMDA receptors by various substances rescues motoneurons and increases the number of motor units surviving into adulthood. In this way, glutamate receptor blockers may represent a promising therapeutic approach to retain nerve and muscle function during neurodegenerative events.

Journal of Shoulder and Elbow Surgery, Dec 1, 2014

Background: Massive rotator cuff tear repair is frequently complicated by unsatisfactory clinical... more Background: Massive rotator cuff tear repair is frequently complicated by unsatisfactory clinical results due to possible tendon retraction, muscle atrophy, and fatty degeneration. The objective of this study was the development of a chronic massive tear in a rat model and the evaluation of the muscle force in vivo and of the histologic changes in a 3-dimensional manner. Methods: To simulate massive rotator cuff tears, both the supraspinatus (SS) and the infraspinatus (IS) tendons were surgically detached from the right humerus of 15 male adult Sprague-Dawley rats. Twelve weeks postoperatively, all animals underwent isometric tension recordings of both the SS and IS muscles. Histologic analysis and image deconvolution processing were performed to estimate the presence and the distribution of atrophy in 3 dimensions. Results: An overall 30% and 35% reduction in muscle force of the SS and IS muscles, respectively, was observed compared with the left uninjured shoulder (P < .005). Histologic analysis revealed that the degeneration and the fatty infiltration were more evident near the tendon and at the dorsal side in both muscle groups. Conclusions: These results show that functional impairment of SS and IS muscles after chronic massive tendon tears could be attributed to the decrease in muscle force production during their repair on the greater tuberosity and, second, to the comparatively greater degeneration of their dorsal part.

European Spine Journal, Jul 9, 2023

Purpose We evaluated the long-term safety, mobility and complications of cervical total disc arth... more Purpose We evaluated the long-term safety, mobility and complications of cervical total disc arthroplasty with the Baguera ® C prosthesis over 10 years. Methods We included 91 patients treated by arthroplasty for cervical degenerative disc disease. A total of 113 prostheses were implanted (50 one-level, 44 two-level and 19 hybrid constructs). They were assessed for complications, clinically, with NDI and SF-12 questionnaires and by independent radiologists for ROM, HO, disc height and adjacent level degeneration. Results No spontaneous migration, loss of fixation, subsidence, vascular complication or dislocation were observed. The reoperation rate was 1%. About 82.7% of the patients were pain free. About 9.9% were taking occasional grade I painkillers. Motricity and sensitivity were preserved in 98.8% and 96.3%. The NDI showed an average functional disability of 17.58%, 26% lower than preoperatively. The SF-12 scores were close to normal health. The average ROM at the treated level was 7.4°. Motion was preserved in 86.6%. Lack of motion was observed in 13.4%. Grades II and III H0 were present in 53.7% and 31.7%, respectively, Grade IV was present in 13.4%. Motion was preserved in 100% of the grades 0-III. The preoperative adjacent level disc height of 4.3 mm remained stable during all the follow-ups at 4.4 mm and 4.2 mm, respectively, at 5 and 10 years. Conclusions After 10 years, cervical arthroplasty with the Baguera ® C prosthesis presents excellent safety and functional results and low complications. Motion was preserved in 86.6%, with a 7.4° ROM. Although common, HO did not hinder motion. Adjacent disc height preservation confirms some adjacent level degeneration protection.

Journal of Neurology, 2004

Stroke, Apr 1, 2019

Background and Purpose-Acute stroke treatment is challenging, and stroke remains a major cause of... more Background and Purpose-Acute stroke treatment is challenging, and stroke remains a major cause of death and disability. The purpose of this meta-analysis is to investigate the effects of postacute stroke intravenous administration of the neuroprotectant magnesium sulfate (MgSO 4) on global outcome, functional outcome, and mortality 90 days poststroke (ischemic and nonischemic). Methods-We searched in Pubmed, Science Direct, CENTRAL, and ClinicalTrials.gov, up to November 11, 2017, and we conducted a systematic review and meta-analysis of randomized controlled trials. We synthesized results by using random-effects model, weighted mean differences, standardized mean differences, and odds ratios. Results-Seven randomized controlled trials (4347 patients) met our criteria. Compared with placebo, treatment did not improve functional outcome defined as Barthel Index >60 (odds ratio =1.05; 95% CI, 0.92-1.19) and >95 (odds ratio =0.95; 95% CI, 0.76-1.20), 90 days poststroke. It also did not improve global outcome measured with modified Rankin Scale (standardized mean difference =−0.01; 95% CI, −0.12 to 0.10), 90 days poststroke. In an additional subgroup metaanalysis that exclusively included ischemic stroke patients, intravenous MgSO 4 resulted in lower modified Rankin Scale score (improved global outcome; weighted mean difference =−0.96; 95% CI, −1.34 to −0.58; I 2 =0%], 90 days poststroke. Finally, mortality stayed unaltered (odds ratio =1.10; 95% CI, 0.94-1.29). Conclusions-The findings of our meta-analysis showed that intravenous MgSO 4 generally did not improve global/ functional outcomes and mortality at 90 days after stroke (combined ischemic stroke and nonischemic stroke). The finding of favorable neurological outcome, selectively in ischemic stroke patients, should be viewed with extreme caution given the limited number of patients included in this subgroup meta-analysis.

Strahlentherapie Und Onkologie, Nov 1, 2009

Background and Purpose: The importance of tumor volume as a prognostic factor in high-grade gliom... more Background and Purpose: The importance of tumor volume as a prognostic factor in high-grade gliomas is highly controversial and there are numerous methods estimating this parameter. In this study, a computer-based application was used in order to assess tumor volume from hard copies and a survival analysis was conducted in order to evaluate the prognostic significance of preoperative volumetric data in patients harboring glioblastomas. Patients and Methods: 50 patients suffering from glioblastoma were analyzed retrospectively. Tumor volume was determined by the various geometric models as well as by an own specialized software (Volumio). Age, performance status, type of excision, and tumor location were also included in the multivariate analysis. Results: The spheroid and rectangular models overestimated tumor volume, while the ellipsoid model offered the best approximation. Volume failed to attain any statistical significance in prognosis, while age and performance status confirmed their importance in progression-free and overall survival of patients. Conclusion: Geometric models provide a rough approximation of tumor volume and should not be used, as accurate determination of size is of paramount importance in order to draw safe conclusions in oncology. Although the significance of volumetry was not disclosed, further studies are definitely required.

Aristotle University Medical Journal, Dec 14, 2014

Introduction: Various experimental models exist in order to induce a spinal cord lesion and to mo... more Introduction: Various experimental models exist in order to induce a spinal cord lesion and to monitor the potential recovery of the animals, with or without any therapeutic means. From the behavioral point of view, the Basso-Beattie-Bresnahan (BBB) score is the most popular scale, used consistently to evaluate the effect of the traumatism onto the motor behavior of the animals. Although it is well established and it is regarded as the "gold standard" in the literature, in case of partial lesions, with high rate of spontaneous recovery, more elaborate tests may be indicated.Materials-methods: In this study we performed spinal cord hemisection at the midthoracic level in adult Wistar rats, which were evaluated postoperatively with BBB, as well as with a more extended behavioral protocol, comprising grid walking and footprint analysis. Results: Although BBB score improved, grid walking, stride length, step length and limb rotation did not reach statistical significance. Conclusion: More sensitive motor behavior protocols are needed to corroborate the results of the BBB test and to detect subtle defects in sensorimotor coordination. This is especially true in cases of partial lesions, due to a high rate of spontaneous gross motor recovery.

International Journal of Molecular Sciences, Dec 19, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Brain and Spine, Dec 31, 2022

Frontiers in Psychiatry

BackgroundFunctional magnetic resonance imaging (fMRI) is a valuable tool for the presurgical eva... more BackgroundFunctional magnetic resonance imaging (fMRI) is a valuable tool for the presurgical evaluation of patients undergoing neurosurgeries. Although many pre-processing steps have been modified according to advances in recent years, statistical analysis has remained largely the same since the first days of fMRI. In this study, we examined the ability of Independent Component Analysis (ICA) to separate the activation of a language task in fMRI, and we compared it with the results of the General Lineal Model (GLM).MethodsSixty patients undergoing evaluation for brain surgery due to various brain lesions and/or epilepsy and 20 control subjects completed an fMRI language mapping protocol that included three tasks, resulting in 259 fMRI scans. Depending on brain lesion characteristics, patients were allocated to (1) static/chronic not-expanding lesions (Group 1) and (2) progressive/expanding lesions (Group 2). GLM and ICA statistical maps were evaluated by fMRI experts to assess the ...

Journal of experimental orthopaedics, 2024

BMC Cancer, Jan 3, 2012

Background: In this study several tumor-related volumes were assessed by means of a computer-base... more Background: In this study several tumor-related volumes were assessed by means of a computer-based application and a survival analysis was conducted to evaluate the prognostic significance of pre-and postoperative volumetric data in patients harboring glioblastomas. In addition, MGMT (O 6-methylguanine methyltransferase) related parameters were compared with those of volumetry in order to observe possible relevance of this molecule in tumor development. Methods: We prospectively analyzed 65 patients suffering from glioblastoma (GBM) who underwent radiotherapy with concomitant adjuvant temozolomide. For the purpose of volumetry T1 and T2-weighted magnetic resonance (MR) sequences were used, acquired both pre-and postoperatively (pre-radiochemotherapy). The volumes measured on preoperative MR images were necrosis, enhancing tumor and edema (including the tumor) and on postoperative ones, net-enhancing tumor. Age, sex, performance status (PS) and type of operation were also included in the multivariate analysis. MGMT was assessed for promoter methylation with Multiplex Ligationdependent Probe Amplification (MLPA), for RNA expression with real time PCR, and for protein expression with immunohistochemistry in a total of 44 cases with available histologic material. Results: In the multivariate analysis a negative impact was shown for pre-radiochemotherapy net-enhancing tumor on the overall survival (OS) (p = 0.023) and for preoperative necrosis on progression-free survival (PFS) (p = 0.030). Furthermore, the multivariate analysis confirmed the importance of PS in PFS and OS of patients. MGMT promoter methylation was observed in 13/23 (43.5%) evaluable tumors; complete methylation was observed in 3/13 methylated tumors only. High rate of MGMT protein positivity (> 20% positive neoplastic nuclei) was inversely associated with pre-operative tumor necrosis (p = 0.021). Conclusions: Our findings implicate that volumetric parameters may have a significant role in the prognosis of GBM patients. Furthermore, volumetry could help not only to improve the prediction of outcome but also the outcome itself by identifying patients at high risk of treatment failure and, thus, seek alternative treatment for these patients. In this small series, MGMT protein was associated with less aggressive tumor characteristics.

Brain Injury, Apr 27, 2022

The Spine Journal, Oct 1, 2015

BACKGROUND CONTEXT: Total disc replacement (TDR) is widely used as alternative treatment to fusio... more BACKGROUND CONTEXT: Total disc replacement (TDR) is widely used as alternative treatment to fusion for symptomatic cervical disc degenerative diseases. Its advantages (ie, functional improvement, preservation of motion and possibly protection of the adjacent segment) are supported by literature data. The influence of the size of prosthesis on surgical outcomes has been less studied and we could not find any data on its correlation with preoperative disc height. PURPOSE: The aim of current analysis is to evaluate the relationship between surgery outcomes assessed two years postoperatively, and preoperative disc height (PDH)/implant height (BCH) ratio, in patients treated by TDR with a semi constrained prosthesis (BAGUERAÒC, Spineart Inc, Switzerland), using a multicentric prospective database. STUDY DESIGN/SETTING: An independent retrospective analysis of clinical and radiographic data was conducted for 99 patients treated with cervical arthroplasty with a two-year follow-up. PATIENT SAMPLE: We included 99 patients (46 males, 53 females), age mean 43.2 (29 to 70) years at surgery time, all treated at 1 to 3 levels. Overall, 123 prosthesis (5, 6, 7 mm height) were implanted: 70, 49, 4 %, respectively. OUTCOME MEASURES: Pre-and postoperatively radiographic data were extracted by an independent evaluator from dynamic lateral radiographs: disc height, ROM (segmental, overall and at the upper level), segmental and overall lordosis. Self-reported questionnaires (VAS, NDI, SF-36) were used for clinical assessment. METHODS: Implant size effect and relationship between PDH/BCH ratio and clinical and radiographic parameters, assessed 2 years after surgery, were respectively analysed. RESULTS: We observed highest mean segmental ROM (8.8) with a 5mm BCH, but better NDI, VAS and SF-36 scores with 6 mm BCH. The PDH/BCH ratio mean was 0.6 (0.5 to 1.5): 74.3% less than 0.9, 17.7% between 0.9-1.1, 8% greater than 1.1. It was significantly correlated (-0.34, p!0.01) with overall ROM, uncorrelated with segmental ROM, lordosis angles and clinical outcomes. Higher correlation (-0.59, p50.04) with overall ROM was observed for PDH/BCH ratio between 0.9-1.1. The PDH/BCH ! 0.9 was associated with lowest NDI and VAS Neck and PDH/BCH O 1.1 with lowest VAS Arm. CONCLUSIONS: Analysed data further demonstrate the clinical benefits of TDR. Despite the lack of correlation with clinical outcomes, better results were observed with small (þ10%) difference between implant size and preoperative disc height. The surgeon may have to choose the implant in order to open the disc height even if this may reduce mobility.

Muscle & Nerve, Nov 22, 2013

Introduction: Quantitative descriptions of fiber type organization in hind limb muscles are incom... more Introduction: Quantitative descriptions of fiber type organization in hind limb muscles are incomplete or rare. Methods: Fiber morphometrics for both rat tibialis anterior (TA) muscles were measured in 3 dimensions. Results: Slow oxidative fiber area and perimeter varied in all zones. Fast oxidative glycolytic fibers (FOG) were predominant in the mediolateral and posterior zones, and fast glycolytic fibers (FG) predominated in the anterior zone. The mean area of FOG and succinate dehydrogenase intermediate fibers was lowest in the anterior zone. Mean area of FG was highest in the proximal and distal parts of the muscle. The area and perimeter of fast fibers differed significantly between the right and left limbs in the medial zone. In the middle and lateral zones, they differed at the proximal and distal parts. Conclusions: This detailed analysis in a high resolution, 3-dimensional map provides an essential tool for understanding the structure and function of TA muscles.

BMC Physiology, May 2, 2012

Background: It is well known that axotomy in the neonatal period causes massive loss of motoneuro... more Background: It is well known that axotomy in the neonatal period causes massive loss of motoneurons, which is reflected in the reduction of the number of motor units and the alteration in muscle properties. This type of neuronal death is attributed to the excessive activation of the ionotropic glutamate receptors (glutamate excitotoxicity). In the present study we investigated the effect of the NMDA antagonist DAP5 [D-2-amino-5phosphonopentanoic acid] in systemic administration, on muscle properties and on behavioural aspects following peripheral nerve injury. Methods: Wistar rats were subjected to sciatic nerve crush on the second postnatal day. Four experimental groups were included in this study: a) controls (injection of 0.9% NaCl solution) b) crush c) DAP5 treated and d) crush and DAP5 treated. Animals were examined with isometric tension recordings of the fast extensor digitorum longus and the slow soleus muscles, as well as with locomotor tests at four time points, at P14, P21, P28 and adulthood (2 months). Results: 1. Administration of DAP5 alone provoked no apparent adverse effects. 2. In all age groups, animals with crush developed significantly less tension than the controls in both muscles and had a worse performance in locomotor tests (p < 0.01). Crush animals injected with DAP5 were definitely improved as their tension recordings and their locomotor behaviour were significantly improved compared to axotomized ones (p < 0.01). 3. The time course of soleus contraction was not altered by axotomy and the muscle remained slow-contracting in all developmental stages in all experimental groups. EDL, on the other hand, became slower after the crush (p < 0.05). DAP5 administration restored the contraction velocity, even up to the level of control animals 4. Following crush, EDL becomes fatigue resistant after P21 (p < 0.01). Soleus, on the other hand, becomes less fatigue resistant. DAP5 restored the profile in both muscles. Conclusions: Our results confirm that contractile properties and locomotor behaviour of animals are severely affected by axotomy, with a differential impact on fast contracting muscles. Administration of DAP5 reverses these devastating effects, without any observable side-effects. This agent could possibly show a therapeutic potential in other models of excitotoxic injury as well.

International Journal of Molecular Sciences, Dec 19, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Journal of Research and Practice on the Musculoskeletal System, Mar 1, 2018

The Systemic Inflammatory Response Syndrome (SIRS) represents the generalized response of the hos... more The Systemic Inflammatory Response Syndrome (SIRS) represents the generalized response of the host to a variety of significant clinical insults, such as infection and trauma. There are specific criteria in the definition, such as: a) hyperor hypothermia, b) heart rate >90/min, c) respirations >20/ minute or PaCO2 <32 mmHg and d) WBC >12,000/mm 3 or <4,000/mm 3 or >10% immature form, with ≥2 of these criteria being necessary. Trauma is one of the more common causes of mortality worldwide. Death is the result of a chain of events starting with the "first hit", which includes severe organ trauma, hypovolemia, hypoxemia or head injury among others. These can lead to the activation of the immune system and the initial inflammatory immune response after trauma can lead to SIRS. If more insults follow, they become the "second hit", which can include infection, ischemia/reperfusion or surgical operations, then the inflammatory response is augmented, together with the mortality of the patient. Musculoskeletal injury through the activation of SIRS can lead to multi-organ failure with the loss of organ systems that were not directly involved by the initial trauma. The result is the activation of various parts/subsets of the immune system, including the neuroendocrine system, and the involvement of hormones or molecules such as ACTH, catecholamines, corticosteroids, cytokines and chemokines. The goal of this presentation is to stress the fact the musculoskeletal trauma is not an isolated injury, as it can lead to the activation of a mechanism meant to protect the organism; however, if it goes "unchecked" then it can easily lead to death.

Developmental Brain Research, Jun 1, 2005

The purpose of this study was to elucidate the effect of deafferentation on spinal motoneurons. W... more The purpose of this study was to elucidate the effect of deafferentation on spinal motoneurons. We studied the effects of spinal cord transection and/or dorsal rhizotomy upon the contractile properties of EDL and soleus muscle, as well as on the number of motoneurons corresponding to these muscles. Neonatal Wistar rats were randomly divided into four groups in which spinal midthoracic section (T8-T10), unilateral dorsal lumbar rhizotomy (L3-S2) or both procedures were performed on the second postnatal day (PND2). Another group served as unoperated control. At 2 months of age, the animals were evaluated for the contractile properties of a fast (EDL) and a slow (soleus) muscle. Isometric tension recordings were elicited by way of sciatic nerve branches stimulation. In addition, the incremental method was applied for the determination of the number of motor units supplying the two muscles, which was also verified by using the horseradish peroxidase (HRP) method of reverse labeling of motoneurons. Muscle alterations were confirmed by the usual biochemical staining. Our results, in agreement with the data from other researchers, show that significant muscle atrophy takes place after all experimental procedures. Additionally, spinal cord section alters the development of the dynamic properties of soleus muscle, which attains a fast profile. Following transection, the number of motor units remained unaltered, while rhizotomy affected only the soleus by reducing its motor units. The combined procedure affected both muscles, indicating that adequate synaptic input is essential for motoneuron survival.

It has been shown in the rat, that during the first five postnatal days, motoneurons are particul... more It has been shown in the rat, that during the first five postnatal days, motoneurons are particularly vulnerable to excitotoxic cell death and glutamate receptors play a significant role in this time-dependent process. Various categories of glutamate blockers (MK-801, Mg, PNQX, DAP-5) have various actions on the respective receptors. Furthermore, the different response between mature and immature motoneurons following injury is attributed to the quantity of glutamate receptors on the cell membrane. The effect of these substances on the recovery of fast and slow muscles after sciatic nerve crush, at critical developmental stages, shows a variable but impressive reversal of the devastating effects on rat muscle properties, which is different between fast and slow muscles. In addition, blocking of NMDA receptors by various substances rescues motoneurons and increases the number of motor units surviving into adulthood. In this way, glutamate receptor blockers may represent a promising therapeutic approach to retain nerve and muscle function during neurodegenerative events.

Journal of Shoulder and Elbow Surgery, Dec 1, 2014

Background: Massive rotator cuff tear repair is frequently complicated by unsatisfactory clinical... more Background: Massive rotator cuff tear repair is frequently complicated by unsatisfactory clinical results due to possible tendon retraction, muscle atrophy, and fatty degeneration. The objective of this study was the development of a chronic massive tear in a rat model and the evaluation of the muscle force in vivo and of the histologic changes in a 3-dimensional manner. Methods: To simulate massive rotator cuff tears, both the supraspinatus (SS) and the infraspinatus (IS) tendons were surgically detached from the right humerus of 15 male adult Sprague-Dawley rats. Twelve weeks postoperatively, all animals underwent isometric tension recordings of both the SS and IS muscles. Histologic analysis and image deconvolution processing were performed to estimate the presence and the distribution of atrophy in 3 dimensions. Results: An overall 30% and 35% reduction in muscle force of the SS and IS muscles, respectively, was observed compared with the left uninjured shoulder (P < .005). Histologic analysis revealed that the degeneration and the fatty infiltration were more evident near the tendon and at the dorsal side in both muscle groups. Conclusions: These results show that functional impairment of SS and IS muscles after chronic massive tendon tears could be attributed to the decrease in muscle force production during their repair on the greater tuberosity and, second, to the comparatively greater degeneration of their dorsal part.

European Spine Journal, Jul 9, 2023

Purpose We evaluated the long-term safety, mobility and complications of cervical total disc arth... more Purpose We evaluated the long-term safety, mobility and complications of cervical total disc arthroplasty with the Baguera ® C prosthesis over 10 years. Methods We included 91 patients treated by arthroplasty for cervical degenerative disc disease. A total of 113 prostheses were implanted (50 one-level, 44 two-level and 19 hybrid constructs). They were assessed for complications, clinically, with NDI and SF-12 questionnaires and by independent radiologists for ROM, HO, disc height and adjacent level degeneration. Results No spontaneous migration, loss of fixation, subsidence, vascular complication or dislocation were observed. The reoperation rate was 1%. About 82.7% of the patients were pain free. About 9.9% were taking occasional grade I painkillers. Motricity and sensitivity were preserved in 98.8% and 96.3%. The NDI showed an average functional disability of 17.58%, 26% lower than preoperatively. The SF-12 scores were close to normal health. The average ROM at the treated level was 7.4°. Motion was preserved in 86.6%. Lack of motion was observed in 13.4%. Grades II and III H0 were present in 53.7% and 31.7%, respectively, Grade IV was present in 13.4%. Motion was preserved in 100% of the grades 0-III. The preoperative adjacent level disc height of 4.3 mm remained stable during all the follow-ups at 4.4 mm and 4.2 mm, respectively, at 5 and 10 years. Conclusions After 10 years, cervical arthroplasty with the Baguera ® C prosthesis presents excellent safety and functional results and low complications. Motion was preserved in 86.6%, with a 7.4° ROM. Although common, HO did not hinder motion. Adjacent disc height preservation confirms some adjacent level degeneration protection.

Journal of Neurology, 2004

Stroke, Apr 1, 2019

Background and Purpose-Acute stroke treatment is challenging, and stroke remains a major cause of... more Background and Purpose-Acute stroke treatment is challenging, and stroke remains a major cause of death and disability. The purpose of this meta-analysis is to investigate the effects of postacute stroke intravenous administration of the neuroprotectant magnesium sulfate (MgSO 4) on global outcome, functional outcome, and mortality 90 days poststroke (ischemic and nonischemic). Methods-We searched in Pubmed, Science Direct, CENTRAL, and ClinicalTrials.gov, up to November 11, 2017, and we conducted a systematic review and meta-analysis of randomized controlled trials. We synthesized results by using random-effects model, weighted mean differences, standardized mean differences, and odds ratios. Results-Seven randomized controlled trials (4347 patients) met our criteria. Compared with placebo, treatment did not improve functional outcome defined as Barthel Index >60 (odds ratio =1.05; 95% CI, 0.92-1.19) and >95 (odds ratio =0.95; 95% CI, 0.76-1.20), 90 days poststroke. It also did not improve global outcome measured with modified Rankin Scale (standardized mean difference =−0.01; 95% CI, −0.12 to 0.10), 90 days poststroke. In an additional subgroup metaanalysis that exclusively included ischemic stroke patients, intravenous MgSO 4 resulted in lower modified Rankin Scale score (improved global outcome; weighted mean difference =−0.96; 95% CI, −1.34 to −0.58; I 2 =0%], 90 days poststroke. Finally, mortality stayed unaltered (odds ratio =1.10; 95% CI, 0.94-1.29). Conclusions-The findings of our meta-analysis showed that intravenous MgSO 4 generally did not improve global/ functional outcomes and mortality at 90 days after stroke (combined ischemic stroke and nonischemic stroke). The finding of favorable neurological outcome, selectively in ischemic stroke patients, should be viewed with extreme caution given the limited number of patients included in this subgroup meta-analysis.

Strahlentherapie Und Onkologie, Nov 1, 2009

Background and Purpose: The importance of tumor volume as a prognostic factor in high-grade gliom... more Background and Purpose: The importance of tumor volume as a prognostic factor in high-grade gliomas is highly controversial and there are numerous methods estimating this parameter. In this study, a computer-based application was used in order to assess tumor volume from hard copies and a survival analysis was conducted in order to evaluate the prognostic significance of preoperative volumetric data in patients harboring glioblastomas. Patients and Methods: 50 patients suffering from glioblastoma were analyzed retrospectively. Tumor volume was determined by the various geometric models as well as by an own specialized software (Volumio). Age, performance status, type of excision, and tumor location were also included in the multivariate analysis. Results: The spheroid and rectangular models overestimated tumor volume, while the ellipsoid model offered the best approximation. Volume failed to attain any statistical significance in prognosis, while age and performance status confirmed their importance in progression-free and overall survival of patients. Conclusion: Geometric models provide a rough approximation of tumor volume and should not be used, as accurate determination of size is of paramount importance in order to draw safe conclusions in oncology. Although the significance of volumetry was not disclosed, further studies are definitely required.

Aristotle University Medical Journal, Dec 14, 2014

Introduction: Various experimental models exist in order to induce a spinal cord lesion and to mo... more Introduction: Various experimental models exist in order to induce a spinal cord lesion and to monitor the potential recovery of the animals, with or without any therapeutic means. From the behavioral point of view, the Basso-Beattie-Bresnahan (BBB) score is the most popular scale, used consistently to evaluate the effect of the traumatism onto the motor behavior of the animals. Although it is well established and it is regarded as the "gold standard" in the literature, in case of partial lesions, with high rate of spontaneous recovery, more elaborate tests may be indicated.Materials-methods: In this study we performed spinal cord hemisection at the midthoracic level in adult Wistar rats, which were evaluated postoperatively with BBB, as well as with a more extended behavioral protocol, comprising grid walking and footprint analysis. Results: Although BBB score improved, grid walking, stride length, step length and limb rotation did not reach statistical significance. Conclusion: More sensitive motor behavior protocols are needed to corroborate the results of the BBB test and to detect subtle defects in sensorimotor coordination. This is especially true in cases of partial lesions, due to a high rate of spontaneous gross motor recovery.

International Journal of Molecular Sciences, Dec 19, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY