Radu Fechete - Academia.edu (original) (raw)
Papers by Radu Fechete
Medic.ro, Apr 27, 2020
Introduction. Osteoporosis and dyslipidemia are two pathological conditions that commonly occur ... more Introduction. Osteoporosis and dyslipidemia are two pathological conditions that commonly occur together, given the common risk factors. This is why it is important not only to choose the appropriate medication that does not have negative side effects on the comorbidities, but when possible, to choose a medication which may bring benefits for many pathologies. Dyslipidemia responds well to hypolipidemic medication, and data from literature show that simvastatin, in addition to the hypolipidemic effect, has also a beneficial effect on bone metabolism. Aim. The purpose of this study is to evaluate the effects of simvastatin on bone healing, respectively the correlation of these effects with the literature data. Materials and method. The study was performed on rats divided into two groups, ovarectomized and neovarectomized, each in turn having two groups, control and treated with simvastatin. Calus evaluation was performed using VIS-nearIR spectrometry to examine hematoxiline eosine (HE) histological stained preparations at different post-fracture periods, respectively 2, 4, 6 and 8 weeks. Results. We observed a decrease of the osteogenic potential in the groups of ovarectomized rats compared to the neovarectomized ones. At the same time, it was also observed an increased osteogenic potential in the groups treated with simvastatin compared with the control group within the group of ovarectomized rats. Conclusions. The difference in osteogenic potential between the two groups underscores the importance of estrogen in the bone healing process. Simvastatin plays a beneficial role in the process of osteogenesis, given the difference between the treated and untreated groups in each group of rats.
Analytical Letters, May 7, 2018
An essential organ of the female reproductive system, the uterus, is histologically divided into ... more An essential organ of the female reproductive system, the uterus, is histologically divided into three layers: the perimetrium, myometrium, and endometrium. In vivo nuclear magnetic resonance (NMR) imaging and spectroscopy are modern methods that become important tools used by radiologists to increase the degree in confidence in their diagnosis, to provide noninvasive metabolic information, and to establish a standardized characterization of the nonpathological tissue. We developed a complex protocol based on in vivo magnetic resonance spectroscopy and imaging correlated with data analysis for the assessment of specific parameters, such as metabolite content, 1 H spin-density, effective transverse relaxation time, and effective longitudinal relaxation time parameter maps, characteristic of normal endometrium in a group of 11 healthy volunteer women. This study involved: (i) a series of data analysis steps performed by a dedicated software and primary NMR signal processing (water and metabolite signal separation, phase and baseline correction, apodization) and (ii) advanced analysis based on dedicated programs. We observed and investigated three states of water: free water, loosely and strongly bound water characterized by different transverse relaxation times. The four most common metabolites reported in previous studies of malignant uterus were identified for normal endometrium. Qualitative transverse and longitudinal relaxation time parameter maps were obtained. The distributions of transverse relaxation times for various uterine areas were demonstrated by statistical analysis. The good signal-to-noise ratio allows the identification of other metabolites such as N-acetyl aspartate and M1 and M2 macromolecular resonances. A relatively high choline and lipid content and low creatine and lactate content were calculated for the group of healthy women.
Biochemical and Biophysical Research Communications, Dec 1, 2022
Applied Magnetic Resonance, Sep 29, 2016
The aim of this work is to show that the bones with marrow, treated as a quasi-porous media, can ... more The aim of this work is to show that the bones with marrow, treated as a quasi-porous media, can be successfully used to study the effects of ovariectomyinduced osteoporosis. Proton one-dimensional (1D) nuclear magnetic resonance (NMR) T 2-distribution and two-dimensional (2D) T 2-T 2 exchange maps combined with histological images were used to measure the proximal part of the femoris, diaphysis and distal epiphysis of ovariectomized and non-ovariectomized Wistar albino rats. The 1D normalized T 2 distributions showed four peaks which were associated with protons in four major pools: (1) the protons from bounded water to collagenous matrix; (2) fluids in osteocyte lacunae and canaliculi channels; (3) fluids in secondary pores like Haversian and transverse Volkmann canals and (4) soft matter like bone marrow and fluids in primary pores like trabecular bone cavities. The peak's association and hierarchical structure of pores in femoral bone were supported by a 2D T 2-T 2 exchange map and by a series of dehydration experiments monitored by NMR measurements. The bone marrow narrows the T 2distributions, increasing resolution, but will not influence significantly the peaks positions; therefore, the NMR relaxometry is a valuable tool to characterize the pore distributions and effects of induced osteoporosis in diverse bones sections.
Studia Universitatis Babeş-Bolyai, Nov 15, 2017
INMATEH-Agricultural Engineering, 2012
Obtaining by thermoplastic extrusion of starch -based biodegradable packaging requires the use of... more Obtaining by thermoplastic extrusion of starch -based biodegradable packaging requires the use of some plasticizers in the formula. Mixing starch with these plasticizers leads to structural and dynamic changes of it. To highlight these changes when using water and glycerol as plasticizers for the cornstarch were performed NMR relaxation measurements. Experimental data were analyzed using inverse Laplace
Studia Universitatis Babeș-Bolyai Physica, 2018
Gels
Whey-based hydrogel samples with increasing concentrations of graphene oxide (GO) were studied, a... more Whey-based hydrogel samples with increasing concentrations of graphene oxide (GO) were studied, against a control sample (M), for swelling behavior in light of nuclear magnetic resonance (NMR) and mathematical models of the diffusion process and for antibacterial activity. Graphene oxide (GO) is an optimal filler for whey-based hydrogels, giving them improved mechanical and swelling properties at low concentrations. Crosslinking induces a certain stiffness of the hydrogels, which is why only the first part of the swelling process (<60%) follows the first-order model, while during the whole time interval, the swelling process follows the second-order diffusion model. The NMR relaxometry results are consistent with the swelling behavior of GO-reinforced whey–gelatin composite hydrogels, showing that higher GO concentrations induce a higher degree of cross-linking and, therefore, lower swelling capacity. Only hydrogel samples with higher GO concentrations demonstrated antibacterial ...
Studia Universitatis Babeș-Bolyai Physica, 2019
Studia Universitatis Babeș-Bolyai Physica, 2018
Cancers
Aim: To evaluate the role of MR relaxometry and derived proton density analysis in the prediction... more Aim: To evaluate the role of MR relaxometry and derived proton density analysis in the prediction of early treatment response after two cycles of neoadjuvant therapy (NAT), in patients with breast cancer. Methods: This was a prospective study that included 59 patients with breast cancer, who underwent breast MRI prior (MRI1) and after two cycles of NAT (MRI2). The MRI1 included a sequential acquisition with five different TE’s (50, 100, 150, 200 and 250 ms) and a TR of 5000 ms. Post-processing was used to obtain the T2 relaxometry map from the MR acquisition. The tumor was delineated and seven relaxometry and proton density parameters were extracted. Additional histopathology data, T2 features and ADC were included. The response to NAT was reported based on the MRI2 as responders: partial response (>30% decreased size) and complete response (no visible tumor stable disease (SD); and non-responders: stable disease or progression (>20% increased size). Statistics was done using ...
The 15th International Conference Interdisciplinarity in Engineering
Medic.ro, Apr 27, 2020
Introduction. Osteoporosis and dyslipidemia are two pathological conditions that commonly occur ... more Introduction. Osteoporosis and dyslipidemia are two pathological conditions that commonly occur together, given the common risk factors. This is why it is important not only to choose the appropriate medication that does not have negative side effects on the comorbidities, but when possible, to choose a medication which may bring benefits for many pathologies. Dyslipidemia responds well to hypolipidemic medication, and data from literature show that simvastatin, in addition to the hypolipidemic effect, has also a beneficial effect on bone metabolism. Aim. The purpose of this study is to evaluate the effects of simvastatin on bone healing, respectively the correlation of these effects with the literature data. Materials and method. The study was performed on rats divided into two groups, ovarectomized and neovarectomized, each in turn having two groups, control and treated with simvastatin. Calus evaluation was performed using VIS-nearIR spectrometry to examine hematoxiline eosine (HE) histological stained preparations at different post-fracture periods, respectively 2, 4, 6 and 8 weeks. Results. We observed a decrease of the osteogenic potential in the groups of ovarectomized rats compared to the neovarectomized ones. At the same time, it was also observed an increased osteogenic potential in the groups treated with simvastatin compared with the control group within the group of ovarectomized rats. Conclusions. The difference in osteogenic potential between the two groups underscores the importance of estrogen in the bone healing process. Simvastatin plays a beneficial role in the process of osteogenesis, given the difference between the treated and untreated groups in each group of rats.
Analytical Letters, May 7, 2018
An essential organ of the female reproductive system, the uterus, is histologically divided into ... more An essential organ of the female reproductive system, the uterus, is histologically divided into three layers: the perimetrium, myometrium, and endometrium. In vivo nuclear magnetic resonance (NMR) imaging and spectroscopy are modern methods that become important tools used by radiologists to increase the degree in confidence in their diagnosis, to provide noninvasive metabolic information, and to establish a standardized characterization of the nonpathological tissue. We developed a complex protocol based on in vivo magnetic resonance spectroscopy and imaging correlated with data analysis for the assessment of specific parameters, such as metabolite content, 1 H spin-density, effective transverse relaxation time, and effective longitudinal relaxation time parameter maps, characteristic of normal endometrium in a group of 11 healthy volunteer women. This study involved: (i) a series of data analysis steps performed by a dedicated software and primary NMR signal processing (water and metabolite signal separation, phase and baseline correction, apodization) and (ii) advanced analysis based on dedicated programs. We observed and investigated three states of water: free water, loosely and strongly bound water characterized by different transverse relaxation times. The four most common metabolites reported in previous studies of malignant uterus were identified for normal endometrium. Qualitative transverse and longitudinal relaxation time parameter maps were obtained. The distributions of transverse relaxation times for various uterine areas were demonstrated by statistical analysis. The good signal-to-noise ratio allows the identification of other metabolites such as N-acetyl aspartate and M1 and M2 macromolecular resonances. A relatively high choline and lipid content and low creatine and lactate content were calculated for the group of healthy women.
Biochemical and Biophysical Research Communications, Dec 1, 2022
Applied Magnetic Resonance, Sep 29, 2016
The aim of this work is to show that the bones with marrow, treated as a quasi-porous media, can ... more The aim of this work is to show that the bones with marrow, treated as a quasi-porous media, can be successfully used to study the effects of ovariectomyinduced osteoporosis. Proton one-dimensional (1D) nuclear magnetic resonance (NMR) T 2-distribution and two-dimensional (2D) T 2-T 2 exchange maps combined with histological images were used to measure the proximal part of the femoris, diaphysis and distal epiphysis of ovariectomized and non-ovariectomized Wistar albino rats. The 1D normalized T 2 distributions showed four peaks which were associated with protons in four major pools: (1) the protons from bounded water to collagenous matrix; (2) fluids in osteocyte lacunae and canaliculi channels; (3) fluids in secondary pores like Haversian and transverse Volkmann canals and (4) soft matter like bone marrow and fluids in primary pores like trabecular bone cavities. The peak's association and hierarchical structure of pores in femoral bone were supported by a 2D T 2-T 2 exchange map and by a series of dehydration experiments monitored by NMR measurements. The bone marrow narrows the T 2distributions, increasing resolution, but will not influence significantly the peaks positions; therefore, the NMR relaxometry is a valuable tool to characterize the pore distributions and effects of induced osteoporosis in diverse bones sections.
Studia Universitatis Babeş-Bolyai, Nov 15, 2017
INMATEH-Agricultural Engineering, 2012
Obtaining by thermoplastic extrusion of starch -based biodegradable packaging requires the use of... more Obtaining by thermoplastic extrusion of starch -based biodegradable packaging requires the use of some plasticizers in the formula. Mixing starch with these plasticizers leads to structural and dynamic changes of it. To highlight these changes when using water and glycerol as plasticizers for the cornstarch were performed NMR relaxation measurements. Experimental data were analyzed using inverse Laplace
Studia Universitatis Babeș-Bolyai Physica, 2018
Gels
Whey-based hydrogel samples with increasing concentrations of graphene oxide (GO) were studied, a... more Whey-based hydrogel samples with increasing concentrations of graphene oxide (GO) were studied, against a control sample (M), for swelling behavior in light of nuclear magnetic resonance (NMR) and mathematical models of the diffusion process and for antibacterial activity. Graphene oxide (GO) is an optimal filler for whey-based hydrogels, giving them improved mechanical and swelling properties at low concentrations. Crosslinking induces a certain stiffness of the hydrogels, which is why only the first part of the swelling process (<60%) follows the first-order model, while during the whole time interval, the swelling process follows the second-order diffusion model. The NMR relaxometry results are consistent with the swelling behavior of GO-reinforced whey–gelatin composite hydrogels, showing that higher GO concentrations induce a higher degree of cross-linking and, therefore, lower swelling capacity. Only hydrogel samples with higher GO concentrations demonstrated antibacterial ...
Studia Universitatis Babeș-Bolyai Physica, 2019
Studia Universitatis Babeș-Bolyai Physica, 2018
Cancers
Aim: To evaluate the role of MR relaxometry and derived proton density analysis in the prediction... more Aim: To evaluate the role of MR relaxometry and derived proton density analysis in the prediction of early treatment response after two cycles of neoadjuvant therapy (NAT), in patients with breast cancer. Methods: This was a prospective study that included 59 patients with breast cancer, who underwent breast MRI prior (MRI1) and after two cycles of NAT (MRI2). The MRI1 included a sequential acquisition with five different TE’s (50, 100, 150, 200 and 250 ms) and a TR of 5000 ms. Post-processing was used to obtain the T2 relaxometry map from the MR acquisition. The tumor was delineated and seven relaxometry and proton density parameters were extracted. Additional histopathology data, T2 features and ADC were included. The response to NAT was reported based on the MRI2 as responders: partial response (>30% decreased size) and complete response (no visible tumor stable disease (SD); and non-responders: stable disease or progression (>20% increased size). Statistics was done using ...
The 15th International Conference Interdisciplinarity in Engineering