9 results on '"M, Guţu"'
Search Results
2. [Assessment of some biophysical parameters of human erythrocyte by FT-IR spectroscopy--preliminary study]
- Author
-
M, Guţu, V, Rusu, Mihaela, Avădanei, Cipriana, Stefănescu, and B, Stoica
- Subjects
Adult ,Male ,Erythrocytes ,Membrane Fluidity ,Erythrocyte Membrane ,Fatty Acids ,Proteins ,Middle Aged ,Risk Assessment ,Sensitivity and Specificity ,Biophysical Phenomena ,Blood Cell Count ,Cholesterol ,Glucose ,Predictive Value of Tests ,Spectroscopy, Fourier Transform Infrared ,Fatty Acids, Unsaturated ,Humans ,Female ,Biomarkers ,Phospholipids ,Triglycerides - Abstract
Based on the biochemical composition of erythrocyte membrane and asymmetric distribution of phospholipids, proteins, and cholesterol, FT-IR spectroscopy can monitor the distribution and interaction pattern of membrane constituents.The study series included 21 clinically healthy subjects aged between 20 and 60 years. Complete blood counts were performed and the serum biochemical compounds (cholesterol, triglycerides, total protein, glucose) were determined.The parameters that can be assessed by erythrocyte FT-IR in relation with the biochemical factors that may influence membrane fluidity are: degree of fatty acids unsaturation, saturated fatty acids/unsaturated fatty acids ratio, cholesterol/phospholipids ratio, and phospholipids/protein ratio. Based on the obtained results, in the assessment of membrane status the following vibration modes were selected as spectral parameters: vibration associated valence bond (=CH), asymmetric valence CH2 groups, modes associated with P=O bond and amine bands I and II specific for proteins. Other parameters, such as v(C-O) specific to glucose, may provide additional information on glucose metabolic status.By correlating biochemical markers with these spectral parameters information on red cell membrane status, status that may reflect different pathological processes, can be obtained.
- Published
- 2011
3. [Membrane fluidity--biophysical parameter in relation to membrane transport processes]
- Author
-
M, Guţu, V, Rusu, and Cipriana, Ştefănescu
- Subjects
Diffusion ,Membrane Lipids ,Cholesterol ,Membrane Microdomains ,Membrane Fluidity ,Biological Transport, Active ,Membrane Proteins ,Hydrophobic and Hydrophilic Interactions ,Biophysical Phenomena ,Phospholipids - Abstract
Membrane fluidity is a complex parameter, influenced both through some biophysical (temperature, electrical charges, pH) and biochemical factors (protein/phospholipids ratio, phospholipids/cholesterol ratio, degree of fatty acids unsaturation). It is a parameter that reflects the main membrane characteristic organization (gel or liquid crystal structure). Experiments provide consistent data about membrane fluidity relations to various cellular processes, especially membrane processes. Passive transport is influenced directly by membrane lipid composition, and consequently, membrane fluidity, or by channels and carriers molecules interactions with adjacent membrane lipids. Membrane diffusion is related both to the hydrophobic nature of the particles and of the membrane environment. Depending on the mode of interaction with membrane proteins, lipids may be classified as non-annular lipids, annular and "mass" lipids. Different types of fatty acids affect the function of many channels, by stimulating or inhibiting them. These effects might be mediated through direct binding of the lipids to the channel or through indirect hydrophobic interactions. Active transport pumps conformation could be modulated, also, through interactions with adjacent lipids of the bilayer (especially cholesterol) and membrane micro-domains organization. In conclusion, membrane fluidity is close related both to passive and active transport.
- Published
- 2011
4. [Scintigraphic visualization of Pgp protein: a non-invasive method to evaluate the MDR cellular character]
- Author
-
Cipriana, Stefănescu, V, Rusu, Daniela, Boişteanu, M, Guţu, S, Makkai, and L, Miron
- Subjects
Lung Neoplasms ,Organotechnetium Compounds ,Sensitivity and Specificity ,Drug Resistance, Multiple ,Cohort Studies ,Cell Transformation, Neoplastic ,Organophosphorus Compounds ,Drug Resistance, Neoplasm ,Predictive Value of Tests ,Humans ,ATP Binding Cassette Transporter, Subfamily B, Member 1 ,Radiopharmaceuticals ,Radionuclide Imaging ,Neoplasm Staging - Abstract
The MDR character is a major factor that influence the effectiveness of cancer chemotherapy. This feature can be noninvasively evaluated through 99mTc isonitrils (MIBI, Tetrofosmin) scintigraphy, because these radiotracers cellular efflux is mediated by the Pgp membranar active transport system, the same that mediate chemotherapy drugs cellular efflux. The Pgp glycoprotein overexpression in the case of the MDR positive tumoral cells will determine both the chemotherapic drug and the isonitrile radiotracer quickly efflux from the cell. This paper present, based both on the literature and personal authors research work, the principle of the method, radiotracers structural characteristics and cellular uptake mechanism, practical protocol details from the acquisition untill the qualitative and quantitative image processing and results interpretation. Quantification indexes are proposed for the radiotracer cellular uptake quantitative evaluation on the scintigraphic image. The results could bring the possibility to make MDR positive patient diagnosis and further selection for the MDR modulators drug therapy.
- Published
- 2010
5. Development and validation of a CFD model used for vertical axis wind turbines simulations.
- Author
-
V Bostan, M Guţu, and I Rabei
- Published
- 2018
- Full Text
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6. Is it enough scintigraphy for everyone? A cross-sectional analysis regarding the impact of justice in the distribution of health care resources.
- Author
-
Miron SD, Guţu M, and Astărăstoae V
- Subjects
- Adult, Child, Cross-Sectional Studies, Female, Health Care Rationing standards, Health Services Accessibility standards, Humans, Male, Middle Aged, Risk Factors, Romania, Surveys and Questionnaires, Age Distribution, Delivery of Health Care standards, Educational Status, Radionuclide Imaging statistics & numerical data, Sex Distribution
- Abstract
Aims: The aim of this study was to evaluate the influence of three demographic criteria: gender, age and education level on the patients that perform a scintigraphy., Materials and Methods: The cross-sectional study was applied to 220 patients to whom it was prescribed a scintigraphy by their treating physician. Of these, 74 were men and 145 women, 10 children and 210 adults. According to their education, 88 people did not graduate a high school, a total of 56 people graduated a high school, 27 persons graduated a college, 22 people had a university diploma and 26 people a PhD title. The chi-square test was used to analyze the frequencies for the measurable variables on a nominal scale. The significance threshold is considered to be 0.05, so, only the values which are smaller were taken into consideration. We presented and analyzed only the data that fulfill this condition., Results and Discussion: From our study it has been found that gender criterion played an important role in performing a scintigraphy for the first time. 71.6% of male patients were undergoing a scintigraphy for the first time. The frequency of exploration by scintigraphy is increasing if you are a female patient than if you are a male patient: chi-square calculated value is chi2 (3)=12.398, p=0.006. From our study it has been found that age item plays an important role in the scintigraphy investigations for all the patients. The first scintigraphy was significantly performed in the 40-50 years old gap, whilst for the patients being aged over 60; they were probably not performing a first time scintigraphy. We did not find significant statistical differences in respect of the education level., Conclusions: So, we can conclude that access to that medical investigation is not depending on the socioeconomic status of the patient, but in some occasions, the number and the frequency distribution of performing a scintigraphy depend on gender and age. We can also conclude that the principle of egalitarianism is fulfilled and so the justice principle in the distribution of health care resources must be reevaluated.
- Published
- 2014
7. [Assessment of some biophysical parameters of human erythrocyte by FT-IR spectroscopy--preliminary study].
- Author
-
Guţu M, Rusu V, Avădanei M, Stefănescu C, and Stoica B
- Subjects
- Adult, Biophysical Phenomena, Blood Cell Count, Cholesterol blood, Erythrocyte Membrane chemistry, Erythrocytes metabolism, Fatty Acids blood, Fatty Acids, Unsaturated blood, Female, Glucose metabolism, Humans, Male, Membrane Fluidity, Middle Aged, Phospholipids blood, Predictive Value of Tests, Proteins metabolism, Risk Assessment, Sensitivity and Specificity, Triglycerides blood, Biomarkers blood, Erythrocytes chemistry, Spectroscopy, Fourier Transform Infrared
- Abstract
Unlabelled: Based on the biochemical composition of erythrocyte membrane and asymmetric distribution of phospholipids, proteins, and cholesterol, FT-IR spectroscopy can monitor the distribution and interaction pattern of membrane constituents., Material and Methods: The study series included 21 clinically healthy subjects aged between 20 and 60 years. Complete blood counts were performed and the serum biochemical compounds (cholesterol, triglycerides, total protein, glucose) were determined., Results and Discussions: The parameters that can be assessed by erythrocyte FT-IR in relation with the biochemical factors that may influence membrane fluidity are: degree of fatty acids unsaturation, saturated fatty acids/unsaturated fatty acids ratio, cholesterol/phospholipids ratio, and phospholipids/protein ratio. Based on the obtained results, in the assessment of membrane status the following vibration modes were selected as spectral parameters: vibration associated valence bond (=CH), asymmetric valence CH2 groups, modes associated with P=O bond and amine bands I and II specific for proteins. Other parameters, such as v(C-O) specific to glucose, may provide additional information on glucose metabolic status., Conclusions: By correlating biochemical markers with these spectral parameters information on red cell membrane status, status that may reflect different pathological processes, can be obtained.
- Published
- 2011
8. [Membrane fluidity--biophysical parameter in relation to membrane transport processes].
- Author
-
Guţu M, Rusu V, and Ştefănescu C
- Subjects
- Biological Transport, Active, Cholesterol metabolism, Diffusion, Hydrophobic and Hydrophilic Interactions, Membrane Lipids chemistry, Membrane Lipids metabolism, Membrane Microdomains metabolism, Membrane Proteins metabolism, Phospholipids metabolism, Biophysical Phenomena, Membrane Fluidity
- Abstract
Membrane fluidity is a complex parameter, influenced both through some biophysical (temperature, electrical charges, pH) and biochemical factors (protein/phospholipids ratio, phospholipids/cholesterol ratio, degree of fatty acids unsaturation). It is a parameter that reflects the main membrane characteristic organization (gel or liquid crystal structure). Experiments provide consistent data about membrane fluidity relations to various cellular processes, especially membrane processes. Passive transport is influenced directly by membrane lipid composition, and consequently, membrane fluidity, or by channels and carriers molecules interactions with adjacent membrane lipids. Membrane diffusion is related both to the hydrophobic nature of the particles and of the membrane environment. Depending on the mode of interaction with membrane proteins, lipids may be classified as non-annular lipids, annular and "mass" lipids. Different types of fatty acids affect the function of many channels, by stimulating or inhibiting them. These effects might be mediated through direct binding of the lipids to the channel or through indirect hydrophobic interactions. Active transport pumps conformation could be modulated, also, through interactions with adjacent lipids of the bilayer (especially cholesterol) and membrane micro-domains organization. In conclusion, membrane fluidity is close related both to passive and active transport.
- Published
- 2011
9. [Scintigraphic visualization of Pgp protein: a non-invasive method to evaluate the MDR cellular character].
- Author
-
Stefănescu C, Rusu V, Boişteanu D, Guţu M, Makkai S, and Miron L
- Subjects
- Cell Transformation, Neoplastic radiation effects, Cohort Studies, Drug Resistance, Multiple, Drug Resistance, Neoplasm, Humans, Lung Neoplasms drug therapy, Lung Neoplasms metabolism, Neoplasm Staging, Predictive Value of Tests, Radionuclide Imaging, Sensitivity and Specificity, ATP Binding Cassette Transporter, Subfamily B, Member 1 metabolism, Lung Neoplasms diagnostic imaging, Lung Neoplasms pathology, Organophosphorus Compounds, Organotechnetium Compounds, Radiopharmaceuticals
- Abstract
The MDR character is a major factor that influence the effectiveness of cancer chemotherapy. This feature can be noninvasively evaluated through 99mTc isonitrils (MIBI, Tetrofosmin) scintigraphy, because these radiotracers cellular efflux is mediated by the Pgp membranar active transport system, the same that mediate chemotherapy drugs cellular efflux. The Pgp glycoprotein overexpression in the case of the MDR positive tumoral cells will determine both the chemotherapic drug and the isonitrile radiotracer quickly efflux from the cell. This paper present, based both on the literature and personal authors research work, the principle of the method, radiotracers structural characteristics and cellular uptake mechanism, practical protocol details from the acquisition untill the qualitative and quantitative image processing and results interpretation. Quantification indexes are proposed for the radiotracer cellular uptake quantitative evaluation on the scintigraphic image. The results could bring the possibility to make MDR positive patient diagnosis and further selection for the MDR modulators drug therapy.
- Published
- 2008
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