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1.
J Enzyme Inhib Med Chem ; 34(1): 218-224, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30560698

RESUMO

The effects of high-intensity interval and continuous exercise on erythrocytes carbonic anhydrase (CA, EC 4.2.1.1) activity levels were scarcely investigated up until now. Here we present a study focused on the CA activity from erythrocytes of athletes experiencing interval and continuous training for 6 weeks, during cold weather and at high altitude (> 1600 m). We observed a 50% increase in the blood CA activity at the second week after initiation of the training in both interval and continuos running groups, whereas the control group did not experience any variation in the enzyme activity levels. In the trained individuals a mild decrease in their body mass, BMI and an increased [Formula: see text] were also observed. The CA activity returned at the basal values after 4-6 weeks after the training started, probably proving that a metabolic compensation occurred without the need of an enhanced enzyme activity. The unexpected 50% rise of activity for an enzyme which acts as a very efficient catalyst for CO2 hydration/bicarbonate dehydration, such as the blood CA, deserves further investigations for better understanding the physiologic basis of this phenomenon.


Assuntos
Altitude , Anidrases Carbônicas/sangue , Temperatura Baixa , Eritrócitos/enzimologia , Treinamento Intervalado de Alta Intensidade , Condicionamento Físico Humano , Corrida/fisiologia , Esportes , Índice de Massa Corporal , Clima , Humanos , Masculino , Consumo de Oxigênio , Distribuição Aleatória , Estudantes , Universidades , Adulto Jovem
2.
Inorg Chem ; 54(23): 11283-91, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26594910

RESUMO

Four new Zn(II)-coordination polymers, namely, [Zn2(µ6-ao2btc)(µ-obix)2]n (1), [Zn2(µ4-ao2btc)(µ-obix)2]n (2), [Zn2(µ4-ao2btc)(µ-mbix)2]n (3), and {[Zn2(µ4-ao2btc)(µ-pbix)2] · 2DMF · 8H2O}n (4), where ao2btc = dioxygenated form of 3,3',5,5'-azobenzenetetracarboxylate and obix, mbix, and pbix = 1,2-, 1,3-, and 1,4-bis(imidazol-1-ylmethyl)benzene, have been synthesized with azobenzenetetracarboxylic acid and isomeric bis(imidazole) ligands and characterized by elemental analyses, IR spectra, single-crystal X-ray diffraction, powder X-ray diffraction, and thermal analyses. X-ray results showed that 1, 2, and 4 had two-dimensional structures with 3,4L13 topology, while 3 was a three-dimensional coordination polymer with bbf topology. For 4, two types of activation strategies, solvent exchange + heating (which produced 4a) and direct heating (which produced 4b), were used to investigate the effect of a guest molecule in a flexible framework. Gas adsorption and iodine encapsulation properties of activated complexes were studied. The CO2 uptake capacities for 4a and 4b were 3.62% and 9.50%, respectively, and Langmuir surface areas calculated from CO2 isotherms were 167.4 and 350.7 m(2)/g, respectively. Moreover, 4b exhibited 19.65% and 15.27% iodine uptake in vapor phase and cyclohexane solution, respectively, which corresponded to 1.47 and 0.97 molecules of iodine/formula unit, respectively. Moreover, photoluminescence properties of the complexes were studied.

3.
Artigo em Inglês | MEDLINE | ID: mdl-24046556

RESUMO

The title compound, [Co(C3H7NO)(H2O)5]SO4·C3H7NO, contains five aqua ligands, a Co(II) atom, a sulfate ion and both a coordinating and a non-coordinating di-methyl-formamide (DMF) mol-ecule. The DMF solvent mol-ecule lies between the complex units, which are located along the b axis. The sulfate ion is for charge balance. The Co(II) atom has distorted octa-hedral coordination geometry, being ligated by five aqua ligands and the O atom of the DMF ligand. O-H⋯O hydrogen bonds between the aqua ligands and the sulfate anion and non-coordinating DMF molecule lead to the formation of a three-dimensional network. Since all constituents lie on a mirror plane, the H atoms of all methyl groups and of one of the aqua ligands are equally disordered over two positions.

4.
Materials (Basel) ; 16(24)2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38138686

RESUMO

We conduct ab-initio electronic structure calculations to explore a novel category of magnetic Heusler compounds, comprising solely 3d transition metal atoms and characterized by high spin magnetic moments. Specifically, we focus on Co2YZ Heusler compounds, where Y and Z represent transition metal atoms such that the order of the valence is Co > Y > Z. We show that these compounds exhibit a distinctive region of very low density of minority-spin states at the Fermi level when crystallizing in the L21 lattice structure. The existence of this pseudogap leads most of the studied compounds to a Slater-Pauling-type behavior of their total spin magnetic moment. Co2FeMn is the compound that presents the largest total spin magnetic moment in the unit cell reaching a very large value of 9 µB. Our findings suggest that these compounds are exceptionally promising materials for applications in the realms of spintronics and magnetoelectronics.

5.
Front Physiol ; 14: 1219780, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38074334

RESUMO

The aim of the study was to determine how the short high-interval training program affects cortisol levels in basketball players. A total of 27 male basketball players volunteered for the study and were randomly assigned to one of two groups: Control Group (CG) (n = 13, mean age; 20,56 ± 1,45 years, mean height; 184,53 ± 6,65 cm) and Experimental Group (EG) (n = 14, mean age; 20,71 ± 2,12 years, mean height; 86,51 ± 8,21 cm). The experimental group received a 7-week interval training program. Blood samples were taken at the beginning and end of the study. Cortisol, Adrenocorticotropic Hormone, Triiodothyronine, Tetraiodothyronine, Parathyroid Hormone, Thyroid Stimulating Hormone, Insulin, and Glucose levels were measured of the EG and CG. To test the differences between groups and compare the effects of pre and post-intervention, a two-way ANOVA for repeated measures was used. Consequently, the post-test levels of TSH, PTH, and ACTH in the exercise group showed a significant difference when compared to the pre-test values (p = 0.000). Moreover, the post-test levels of Glucose, Cholesterol, Triglyceride, HDL, and Mg in the exercise group showed statistical significance when compared to the pre-test values (p = 0.000). Significant differences were seen in the post-test PTH and ACTH levels of the control group when compared to the pre-test values (p = 0.000). Furthermore, the exercise group showed significant differences in post-test values for HDL and Cholesterol compared to the pre-test (p = 0.000). In addition, when comparing the post-test values and pre-test values of both the exercise group and the control group, it was found that all parameters, with the exception of Ca, exhibited substantial differences in favor of the exercise group. It may be claimed that the implementation of interval training has favorable outcomes on pituitary function parameters. Additionally, the regulation of energy consumption during exercise is favourably influenced, along with the reduction of physiological stress resulting from prolonged exercise.

6.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 8): m1045, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22904721

RESUMO

In the title compound, [Cu(NO(3))(2)(C(5)H(6)N(2))(4)], the Cu(II) ion is located on an inversion centre. It features a Jahn-Teller-distorted octa-hedral coordination geometry, defined by four N atoms of four 1-vinyl-imidazole ligands in the equatorial plane and two nitrate O atoms in the axial positions. The nitrate anion is disordered over two sets of sites in a 0.801 (6):0.199 (6) ratio. In the crystal, the complex mol-ecules are linked by weak inter-molecular C-H⋯O and C-H⋯π inter-actions.

7.
Photodiagnosis Photodyn Ther ; 39: 103024, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35870774

RESUMO

BACKGROUND: Optical coherence tomography (OCT) measurements of central choroidal thickness (CCT) and retinal thickness have been proposed as inflammatory indicators for a variety of systemic disorders, particularly those with a vascular component. The relationship between nephrotic syndrome (NS) and visual impairment is not clear. The aim of this study was to evaluate the ocular changes in primary NS patients with preserved renal functions. METHODS: A total of 60 participants (30 NS patients, 30 healthy control subjects) was recruited in this cross-sectional and comparative study. Retinal and choroidal examinations were performed via the spectral domain OCT. Enhanced depth imaging (EDI) mode of the OCT was used for choroidal analysis. RESULTS: Although not statistically significant, CCT was found to be higher in the NS group compared to the control group (p = 0.07). Central foveal thickness (CFT) and retinal arteriolar caliber (RAC) values were statistically significantly lower in the patients with nephrotic syndrome, whereas retinal venular caliber (RVC) and choroidal vascularity index (CVI) values were similar in both groups. RAC and RVC were not statistically significantly correlated with CCT or CFT in both groups (p > 0.05). CONCLUSION: The results of the current study showed a significant difference between the NS group and the control group in terms of some ocular changes (i.e., CFT and RAC). As a result, CCT, CFT and RAC measurements with OCT may be used as a marker of inflammation in NS patients.


Assuntos
Síndrome Nefrótica , Fotoquimioterapia , Corioide/irrigação sanguínea , Corioide/diagnóstico por imagem , Estudos Transversais , Humanos , Rim/fisiologia , Síndrome Nefrótica/complicações , Fotoquimioterapia/métodos , Tomografia de Coerência Óptica/métodos
8.
Sci Rep ; 10(1): 3127, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32080220

RESUMO

Lasing behavior of optically active planar topological Weyl semimetal (TWS) is investigated in view of the Kerr and Faraday rotations. Robust topological character of TWS is revealed by the presence of Weyl nodes and relevant surface conductivities. We focus our attention on the surfaces where no Fermi arcs are formed, and thus Maxwell equations contain topological terms. We explicitly demonstrate that two distinct lasing modes arise because of the presence of effective refractive indices which lead to the birefringence phenomena. Transfer matrix is constructed in such a way that reflection and transmission amplitudes involve 2 × 2 matrix-valued components describing the bimodal character of the TWS laser. We provide associated parameters of the topological laser system yielding the optimal impacts. We reveal that gain values corresponding to the lasing threshold display a quantized behavior, which occurs due to topological character of the system. Our proposal is supported by the corresponding graphical demonstrations. Our observations and predictions suggest a concrete way of forming TWS laser and coherent perfect absorber; and are awaited to be confirmed by an experimental realization based on our computations.

9.
Rev Int Androl ; 18(4): 151-158, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31953028

RESUMO

INTRODUCTION AND OBJECTIVES: To examine the association between lifestyle factors (body mass index, smoking, alcohol consumption, coffee intake, physical activity, sauna and cell phone usage, wearing tight-fitting underwear), and conventional semen parameters. MATERIALS AND METHODS: 1311 participants who attended the Andrology Clinic were included in the study. All participants were separated into two groups as men with normozoospermia and dysspermia. All participants answered a questionnaire which contains questions about the modifiable lifestyle factors. The total risk scores were calculated after all the positive lifestyle factors had been counted. RESULTS: Men with normozoospermia and dysspermia consisted of 852 (65.0%) and 459 (35.0%) participants respectively. A negative relationship between the wearing of tight underwear and having normal semen parameters was detected between the two groups (p=0.004). While going to a sauna regularly was negatively related to semen concentration, wearing tight underwear was also related to both lower motility, normal morphology as well as semen concentration (p<0.05). While the total score of all participants was 5.22±1.34 point, there were no statistical differences between the two groups (p=0.332). It was found that having 3 more or fewer points was not related to any type of semen parameters and results of a spermiogram. CONCLUSION: The clinicians should give advice to infertile male patients about changing their risky lifestyle, for infertility, to a healthy lifestyle for fertility. Better designed studies, with larger sample sizes using conventional semen analysis with sperm DNA analysis methods, should be planned to identify the possible effects of lifestyle factors on semen quality.


Assuntos
Estilo de Vida , Sêmen/fisiologia , Espermatozoides/fisiologia , Adulto , Índice de Massa Corporal , Vestuário , Humanos , Masculino , Análise do Sêmen , Contagem de Espermatozoides , Motilidade dos Espermatozoides/fisiologia , Espermatozoides/patologia , Banho a Vapor/efeitos adversos , Inquéritos e Questionários , Adulto Jovem
10.
Dalton Trans ; 49(31): 10824-10831, 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32700692

RESUMO

A porous Zn(ii)-coordination polymer, namely {[Zn2(µ8-abtc)(betib)]·DMF}n (1), was solvothermally synthesized from 3,3',5,5'-azobenzenetetracarboxylate (abtc4-) and 1,4-bis(2-ethylimidazol-1-yl)butane (betib) ligands and {[Zn2(µ8-abtc)(betib)]·H2O}n (2) was obtained through the immersion of 1 in methanol. Compounds 1 and 2 were structurally characterized via numerous techniques. Both compounds displayed a 3D porous framework with a 3,6-connected sqc5381 net. Compound 2a obtained at 140 °C from 2 exhibited gas and iodine adsorption properties. Interestingly, the compound adsorbed selectively CO2 with the uptake capacity of 54.02 cm3 g-1 (13.26%) over N2 (5.43 cm3 g-1) and CH4 (14.53 cm3 g-1) at 273 K. The compound also adsorbed iodine with the weights of 19.99% and 30.26% in solution and vapor phases, respectively. The single crystal X-ray result and Raman spectra showed the presence of iodine units in the pores of the framework.

11.
J Enzyme Inhib Med Chem ; 24(5): 1141-7, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19772487

RESUMO

The antioxidant activity of some amido-carbonyl oximes containing a C=O and -NH-R adjacent to the oxime group, [Phenyl-C(=O)-C(=N-OH)-N(-H)-Phenyl(-R)] where R= H, 4-chloro, 4-methyl, 4-methoxy, 3,4-dichloro, 3,4-dimethyl, 3-chloro-4-dimethyl, 3-chloro-4-methoxy, naphthyl and an amido-carbonyl dioxime were investigated in vitro by ferric thiocyanate, total reducing power by potassium ferricyanide reduction, 1,1-diphenyl-2- picryl-hydrazyl (DPPH(.)) free radical scavenging, ferrous ions chelating, superoxide anion radical scavenging and hydrogen peroxide scavenging activity assays. The results indicated that the amido-carbonyl oximes have powerful antioxidant capacity.


Assuntos
Amidas/química , Antioxidantes/química , Sequestradores de Radicais Livres/química , Oximas/química , Amidas/síntese química , Antioxidantes/síntese química , Sequestradores de Radicais Livres/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oxirredução , Oximas/síntese química
12.
J Gastroenterol ; 42(6): 461-8, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17671761

RESUMO

BACKGROUND: In this study, we investigated the effect of leptin on caspase-3, caspase-8, and caspase-9 immunoreactivity and lipid peroxidation in the stomachs of rats exposed to cold-restraint stress. METHODS: Thirty-two male Wistar Albino rats were used. Rats pretreated with leptin (10 microg/kg per day for 7 days) were restrained in a wire cage for 4 h at 4 degrees C. Spectrophotometric techniques were used for detection of malondialdehyde (MDA) and glutathione (GSH) levels, and immunoreactivity of caspases was investigated by immunohistochemistry. RESULTS: While the stomach MDA level of the cold-restraint stress group was increased significantly, the level of GSH was decreased when compared with the control group. Caspase-9 and caspase-3 immunoreactivities of the stress group were not changed, while caspase-8 immunoreactivity was decreased. Leptin administration prevented the increase in the MDA level and the decrease in the GSH content of the gastric mucosa in animals subjected to stress. Leptin administration produced no significant change in caspase-8 immunoreactivity but caused a decrease in caspase-3 immunoreactivity. CONCLUSIONS: Cold-restraint stress decreases the antioxidant capacity of stomach tissue while activating oxidants, and induces apoptosis by an increase in caspase immunoreactivity. The presence of leptin reverses these mechanisms and suppresses the apoptosis.


Assuntos
Apoptose , Caspase 3/imunologia , Caspase 8/imunologia , Caspase 9/imunologia , Mucosa Gástrica/imunologia , Mucosa Gástrica/metabolismo , Leptina/fisiologia , Peroxidação de Lipídeos , Estresse Fisiológico/imunologia , Estresse Fisiológico/metabolismo , Animais , Masculino , Ratos , Ratos Wistar
13.
Case Rep Nephrol ; 2017: 5760254, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28815095

RESUMO

Acinetobacter lwoffii, a nonfermentative gram-negative aerobic bacillus, which presents in the normal flora of the oropharynx and skin, has recently been reported as a cause of human infection. Herein, the authors present a case report of peritonitis related to automated peritoneal dialysis caused by A. lwoffii.

14.
Spectrochim Acta A Mol Biomol Spectrosc ; 134: 233-43, 2015 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-25022494

RESUMO

The experimental and theoretical investigation results of a novel organic squarate salt of 4-Morpholinium bis(hydrogen squarate) (1), C6H14ON(+)·C8H3O8(-), were reported in this study. The crystal structure of the title compound was found to crystallize in the triclinic P-1 space group. In the crystals of 1 the morpholine ring adopts the chair conformation with the ethyl group in the equatorial and hydrogen atoms in axial positions. The hydrogen squarate anions are linked into a homoconjugated anion, [(HSQ)2H], by a short symmetric, nonlinear O8⋯H2⋯O2 hydrogen bond of 2.444 (2)Å. The structural and vibrational properties of the compound were also studied by computational methods of ab-initio performed on the compound at DFT/B3LYP/6-31++G(d,p) (2) and HF/6-31++G(d,p) (3) level of theory. The obtained calculation results on the basis of two models for both the optimized molecular structure and vibrational properties for the 1 obtained are presented and compared with the X-ray analysis result. On the other hand the molecular electrostatic potential (MEP), electronic absorption spectra, frontier molecular orbitals (FMOs), conformational flexibility and non-linear optical properties (NLO) of the title compound were also studied at the 2 level and the results are reported. In order to evaluate the suitability for NLO applications thermal analysis (TG, DTA and DTG) data of 1 were also obtained.


Assuntos
Ciclobutanos/química , Morfolinas/química , Teoria Quântica , Técnicas de Química Sintética , Cristalografia por Raios X , Ciclobutanos/síntese química , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Morfolinas/síntese química , Prótons , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
15.
Dalton Trans ; 44(4): 1627-35, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25436449

RESUMO

Two new coordination complexes, namely, [Cu(tdp)(H2O)(bim)3]·4H2O (1) and {[Cu(µ2-tdp)(bim)2]·4H2O}n (2) (tdp = 3,3'-thiodipropionate, bim = benzimidazole), having naked-eye sensor properties and thermochromic behaviors, were synthesized and structurally characterized using elemental analysis, IR and UV spectra, and single-crystal X-ray diffraction, powder X-ray diffraction (PXRD) and thermal analyses (TG, DTA and DTG) techniques. Complex 1 changed color from blue to dark and light green in methanol and DMF solvents, respectively, while complex 2 changed color from light blue to light green only in DMF solvent. Moreover, complex 1 can be used to detect as little as 10 percent methanol in ethanol by the naked eye. The thermochromic properties of the complexes showed that complexes 1 and 2 changed color from blue and light blue to light and dark green at 65 °C, respectively.

16.
Turk J Anaesthesiol Reanim ; 41(6): 223-5, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27366376

RESUMO

A ventricular assist device (VAD) is a mechanical pump used to support heart function and blood flow in patients with poor heart functions. For selected patients who are too ill to wait for a heart transplant or are not eligible for a heart transplant because of age or other medical problems, ventricular assist devices offer life-saving therapy. This device has also become a life-saving approach for patients with acute viral myocarditis. Following the acute illness phase, when heart function has improved, the VAD is carefully removed. It is very important to continuously monitor myocardial functions during this period. In this paper, we present a patient who underwent cardiac output and transesophageal echocardiography monitoring during VAD removal.

18.
Artigo em Inglês | MEDLINE | ID: mdl-22999164

RESUMO

A new thiourea derivative, 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea (bcht) has been synthesized from the reaction of 2-amino-4-chlorophenol with benzoyl isothiocyanate. The title compound has been characterized by elemental analyses, FT-IR, (13)C, (1)H NMR spectroscopy and the single crystal X-ray diffraction analysis. The structure of bcht derived from X-ray diffraction of a single crystal has been presented. The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional method using 6-311++G(d,p) basis set. The complete assignments of all vibrational modes were performed on the basis of the total energy distributions (TED). Isotropic chemical shifts ((13)C NMR and (1)H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. Theoretical calculations of bond parameters, harmonic vibration frequencies and nuclear magnetic resonance are in good agreement with experimental results. The UV absorption spectra of the compound that dissolved in ACN and MeOH were recorded. Bcht was also screened for antimicrobial activity against pathogenic bacteria and fungi.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Feniltioureia/análogos & derivados , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Cristalografia por Raios X , Fungos/efeitos dos fármacos , Halogenação , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Micoses/tratamento farmacológico , Feniltioureia/química , Feniltioureia/farmacologia , Teoria Quântica , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Turk Neurosurg ; 21(4): 471-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22194102

RESUMO

AIM: Cerebro-spinal fluid (CSF) leakage caused by defects on the dura mater after trauma or some neurosurgical interventions is an important issue. In this study, we investigated the effects of local and systemic use of phenytoin sodium on dural healing. MATERIAL AND METHODS: Thirty-six male Wistar rats were divided into control, local phenytoin and systemic phenytoin groups with 12 rats in each. For each group, a dura defect was created at thoracic segment. Subjects were sacrificed at following 1st and 6th weeks and damaged segments were isolated. The results were compared histopathologically by Hematoxylin-Eosin and Masson-Trichrome staining. Criteria for the rate of collagen, neovascularization, and granulation formation were assessed semi quantitatively according to the histological assessment scale modified by Ozisik et al. RESULTS: Better healing was achieved in the systemic and local phenytoin groups than in the control group. The level of healing was significantly higher in the systemic group in both early and late periods than in other groups (p < 0.01). The level of healing in the late-local group was also statistically significantly higher than that in the control group. CONCLUSION: We observed that both systemic and local uses of phenytoin sodium (especially systemic) have positive effects on dura healing.


Assuntos
Anticonvulsivantes/farmacologia , Rinorreia de Líquido Cefalorraquidiano/tratamento farmacológico , Dura-Máter/lesões , Fenitoína/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Vazamento de Líquido Cefalorraquidiano , Rinorreia de Líquido Cefalorraquidiano/metabolismo , Modelos Animais de Doenças , Dura-Máter/metabolismo , Dura-Máter/cirurgia , Tecido de Granulação/efeitos dos fármacos , Masculino , Procedimentos Neurocirúrgicos , Ratos , Ratos Wistar
20.
World J Biol Psychiatry ; 10(4 Pt 2): 531-43, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19707959

RESUMO

Methylphenidate is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder of children and young adults. Our aim is to investigate dose-dependent dopamine-2 receptor and glial fibrillary acidic protein expression and ultrastructural changes of the rat brain, to demonstrate possible toxicity of the long-term and high dose use of the methylphenidate. In this study, 27 female prepubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) were treated orally with methylphenidate dissolved in saline solution for 5 days per week during 3 months. At the end of the third month, tissues were removed and sections were collected for immunohistochemical and ultrastructural studies. We believe that methylphenidate causes dose-related activation of the dopaminergic system in several brain regions especially in ventral tegmental area and also causing neuronal degeneration and capillary wall structural changes such as basal membrane thickness and augmentation of the pinostatic vesicle in the endothelial cells. Also, increased dose of Ritalin is inducing astrocytes hypertrophy especially astrogliosis in pia-glial membrane and this is the result of the degenerative changes in prefrontal cortex region due to high dose methylphenidate administration. The dose-related accumulation of the astrocytes in capillary wall might well be a consequence of the need for nutrition of the neuronal tissue, due to transport mechanism deficiency related to neuronal and vascular degeneration. Thus, we believe that the therapeutic dose of methylphenidate must be kept in minimum level to prevent ultrastructural changes.


Assuntos
Estimulantes do Sistema Nervoso Central/toxicidade , Cerebelo/efeitos dos fármacos , Cérebro/efeitos dos fármacos , Metilfenidato/toxicidade , Administração Oral , Fatores Etários , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Capilares/efeitos dos fármacos , Capilares/patologia , Estimulantes do Sistema Nervoso Central/administração & dosagem , Cerebelo/patologia , Cérebro/patologia , Dopamina/metabolismo , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Técnicas Imunoenzimáticas , Metilfenidato/administração & dosagem , Degeneração Neural/induzido quimicamente , Degeneração Neural/patologia , Pinocitose/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/patologia , Ratos , Ratos Wistar , Receptores de Dopamina D2/efeitos dos fármacos , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/patologia
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