RESUMO
Despite the high degree of scientific and methodological developments in the field of determining the mechanism of formation of injuries arising from the effects of sharp objects, injuries caused by scissors are practically not covered. The purpose of the study was to collect and analyze foreign literature reflecting the study of injuries to the human body caused by scissors. In the review, the authors have collected all currently available foreign publications on the study of injuries caused by this traumatic object, analyzed and concluded about the relevance of the problem of in-depth study of injuries caused by scissors, including in connection with the spread of new designs of this trauma tool in everyday life.
Assuntos
Crime , Medicina Legal , HumanosRESUMO
A case from practice is presented - the infliction of fatal self-harm with clerical scissors with the formation of a comminuted depressed terrace-like fracture of the cranial vault. The given case is interesting for forensic experts, first of all, because it demonstrates the possibility of suicide with an unusual object - scissors and an area of injury that is unlikely for self-infliction - the vault of the skull.
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Comportamento Autodestrutivo , Fraturas Cranianas , Suicídio , Medicina Legal , Humanos , CrânioRESUMO
PURPOSE: To study the connective tissue (CT) structure of upper eyelid skin of primary open-angle glaucoma (POAG) patients. PATIENTS AND METHODS: Forty-seven patients aged 47-91 expecting blepharoplasty formed 3 groups: group 1 [16 subjects without POAG, median age 55 years (interquartile range 54-55.5)], group 2 [12 subjects without POAG, median age 73 (72-76.5)], and group 3 [(19 subjects with POAG, median age 74 (70-80.5)]. Age differences between groups 1 and 2 and groups 1 and 3 are significant (p < 0.05). Thermodynamic parameters of skin samples taken during blepharoplasty: Endothermic peak ([Formula: see text], °C) and denaturation enthalpy ([Formula: see text], J/g of dry weight) were determined using differential scanning calorimetry. RESULTS: [Formula: see text] and [Formula: see text] in groups 1-3 were, respectively, 8.41 (7.42-10.25) and 66.55 (59.9-66.7); 7.10 (5.76-10.17) and 67.35 (67.0-68.03); 11.40 (9.0-14.9) and 67.70 (67.05-68.45). [Formula: see text] differences between groups 1 and 2 are significant (p < 0.05), and Spearman's correlation between the age and [Formula: see text] is direct, medium (R = 0.638) and significant. [Formula: see text] in group 3 is significantly higher than in group 2. [Formula: see text] and [Formula: see text] in patients without POAG (groups 1 and 2) and those with POAG (group 3) are, respectively, 7.79 (6.9-10.17) and 66.6 (61.2-67,3); 11.40 (9.0-14.9); 67.7 (67.05-68.45); the respective differences are significant. CONCLUSION: Patients without POAG show a significant increase in [Formula: see text] with age, while [Formula: see text] slightly decreases. In POAG, [Formula: see text] is significantly higher and [Formula: see text] tends to grow, which may indicate structural changes in eyelid CT (collagen accumulation and cross-linking level rise). Since the upper lid is unaffected by increasing IOP directly, the changes may be viewed as manifestations of systemic CT pathology.
Assuntos
Tecido Conjuntivo/patologia , Pálpebras/patologia , Glaucoma de Ângulo Aberto/diagnóstico , Tomografia de Coerência Óptica/métodos , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Colorimetria , Tecido Conjuntivo/fisiopatologia , Pálpebras/fisiopatologia , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Termodinâmica , Campos Visuais/fisiologiaRESUMO
At present, a steady growth in the frequency of wounds inflicted by sharp injurious objects (e.g. scissors) is being observed. It necessitates an enhanced attention to the investigation of the causes underlying such events and the circumstances accompanying them. This article presents an example of one of the injuries inflicted with scissors that required the most careful and comprehensive criminalistic study despite the seemingly self-evident circumstances of the event. This case illustrates the necessity of development of the modern algorithms for the evaluation of the injuries inflicted with the scissors.
Assuntos
Algoritmos , Ferimentos Penetrantes/etiologia , Utensílios Domésticos , Humanos , Ferimentos Penetrantes/diagnósticoRESUMO
AIM: to study long-term (≥2-year) RESULTS of ranibizumab treatment in patients with macular neovascular disorders. MATERIAL AND METHODS: The study group included 27 patients (mean age±SD of 66.7±13.8 years) treated with ranibizumab for approved indications. Follow-up period ranged from 24 to 58 months (34.5±9.1 months on average). RESULTS: Optical coherence tomography showed statistically significant improvements of functional and anatomical parameters, namely, an increase in visual acuity (from 0.34±0.20 to 0.57±0.24, p≤0.01) and a decrease in both central retinal thickness (from 372.26±96.21 µm to 272.48±69.70 µm, p≤0.01) and macular volume (from 8.01±1.46 mm3 to 7.10±1.08 mm3, p≤0.01). There was also a decreasing tendency of the average annual number of intravitreal ranibizumab injections per patient: 4.56 injections were done during the 1st year, 1.93 - during the 2nd year, and only 1.6 - during the 3rd year of follow-up. A total of 29.6% of patients showed no need in resuming the treatment at year 2 and 40.0% - at year 3. Exudation from the neovascular membrane relapsed in 24 patients (88.9%) at some time during the follow-up; at that, in 74.1% of patients the injection-free intervals lasted from 6 to 36 months. None of the 231 injections was associated with any complications concerning ocular functions and morphology and requiring additional treatment. No correlation was found between the anti-angiogenic therapy and the progression of cardiovascular disease. CONCLUSION: Intravitreal ranibizumab has been proved effective and safe for the treatment of neovascular macular disorders. Moreover, flexible dosing schemes for ranibizumab contribute to rapid (during the 1st year already) and stable clinical benefits.
RESUMO
The authors report a case of forensic medical expertise demonstrating the potential of the dermatoglyphic technique as a tool for the identification of the personality traits of unknown individuals including their race and ethnic background, biological age, constitutional characteristics, congenital and acquired pathologies and injuries. It was shown that the results of the dermatoglyphic studies agree with and complement the data obtained with the help of a set of traditional forensic medical investigations, such as urological, odontoscopic, and roentgenological ones. An important advantage of the dermatoglyphic techniques is the possibility of their application under conditions when the choice and the use of the alternative methods are limited by the specific features of the objects of forensic medical expertise and the lack of time.
Assuntos
Determinação da Idade pelo Esqueleto/métodos , Determinação da Idade pelos Dentes/métodos , Dermatoglifia , Antropologia Forense/métodos , Análise para Determinação do Sexo/métodos , Adolescente , Adulto , Humanos , MasculinoRESUMO
BACKGROUND: Microalgae have attracted considerable interest due to their ability to produce a wide range of valuable compounds. Pulsed Electric Fields (PEF) has been demonstrated to effectively disrupt the microalgae cells and facilitate intracellular extraction. To increase the commercial viability of microalgae, the entire biomass should be exploited with different products extracted and valorized according to the biorefinery scheme. However, demonstrations of multiple component extraction in series are very limited in literature. This study aimed to develop an effective lipid extraction protocol from wet Scenedesmus almeriensis after PEF-treatment with 1.5 MJ·kgDW-1. A cascade process, i.e., the valorization of several products in row, was tested with firstly the collection of the released carbohydrates in the water fraction, then protein enzymatic hydrolysis and finally lipid extraction. Biomass processed with high pressure homogenization (HPH) on parallel, served as benchmark. RESULTS: Lipid extraction with ethanol:hexane (1:0.41 vol/vol) offered the highest yields from the different protocols tested. PEF-treatment promoted extraction with almost 70% of total lipids extracted against 43% from untreated biomass. An incubation step after PEF-treatment, further improved the yields, up to 83% of total lipids. Increasing the solvent volume by factor 2 offered no improvement. In comparison, extraction with two other systems utilizing only ethanol at room temperature or elevated at 60 °C were ineffective with less than 30% of total lipids extracted. Regarding cascade extraction, carbohydrate release after PEF was detected albeit in low concentrations. PEF-treated samples displayed slightly better kinetics during the enzymatic protein hydrolysis compared to untreated or HPH-treated biomass. The yields from a subsequent lipid extraction were not affected after PEF but were significantly increased for untreated samples (66% of total lipids), while HPH displayed the lowest yields (~ 49% of total lipids). CONCLUSIONS: PEF-treatment successfully promoted lipid extraction from S. almeriensis but only in combination with a polar:neutral co-solvent (ethanol:hexane). After enzymatic protein hydrolysis in cascade processing; however, untreated biomass displayed equal lipid yields due to the disruptive effect of the proteolytic enzymes. Therefore, the positive impact of PEF in this scheme is limited on the improved reaction kinetics exhibited during the enzymatic hydrolysis step.
RESUMO
Two DNase I-hypersensitive regions are identified on the regulatory region of the rat tryptophan dioxygenase (tdo) gene which is expressed tissue-specifically under control ofglucocorticoid hormones. DNase I-hypersensitive regions are identified in position -470 and in the vicinity of the first upstream gene. Micrococcal nuclease digestion pattern of this region shows disturbances in the regular cleavage and appearance of shorter DNA molecules than nucleosomal DNA. However the control experiments demonstrate that the same DNA region could be involved in the regular nucleosome core particles under in vitro reconstitution. Taken together, these data show that the nucleosome array in the regulatory region of the actively transcribed tdo gene in vivo is disturbed.
Assuntos
Montagem e Desmontagem da Cromatina , Nucleossomos/metabolismo , Sequências Reguladoras de Ácido Nucleico , Transcrição Gênica , Triptofano Oxigenase/genética , Animais , Desoxirribonuclease I/química , Fígado/enzimologia , Masculino , RatosRESUMO
Herein we demonstrate temperature-dependent sacrificial singlet oxygen scavenging properties of N-butyl-2-pyridone, ensuring efficient stimuli-responsive protection of densely populated excited triplet state ensembles against deactivation by molecular oxygen. As an acting external stimulus the temperature was chosen: it will be shown that at low temperature the concentration of singlet oxygen will be substantially lowered; in contrast, at elevated temperatures singlet oxygen will not be captured, and thus the optically excited densely populated triplet ensembles will be effectively depopulated. The singlet oxygen scavenging ability of N-butyl-2-pyridone demonstrates long-term protection of a triplet-triplet annihilation upconversion process against photooxidation.
RESUMO
Calcitriol (1 alpha,25-dihydroxycholecalciferol) inhibits prostate cancer cell growth. It has been shown that inhibition of growth of prostate cancer LNCaP cells by calcitriol is androgen-dependent. Using cDNA microarray we showed that calcitriol induced expression of placental transforming growth factor-beta (PTGF-beta), which is known to suppress cell growth. We studied regulation of PTGF-beta gene expression by calcitriol and 5alpha-dihydrotestosterone and analyzed whether induction of PTGF-beta transcription by calcitriol is androgen-dependent. Using real-time PCR we demonstrate that 5alpha-dihydrotestosterone up-regulates PTGF-beta mRNA. We do not find an effect of 5alpha-dihydrotestosterone or antiandrogen Casodex on calcitriol-induced PTGF-beta mRNA level and conclude that induction of PTGF-beta transcription by calcitriol is androgen-independent.
Assuntos
Androgênios/fisiologia , Proteínas Morfogenéticas Ósseas/biossíntese , Calcitriol/farmacologia , Proteínas de Membrana/biossíntese , Neoplasias da Próstata/metabolismo , 5-alfa-Di-Hidroprogesterona/farmacologia , Antagonistas de Androgênios/farmacologia , Anilidas/farmacologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Fator 15 de Diferenciação de Crescimento , Humanos , Masculino , Nitrilas , Neoplasias da Próstata/patologia , Compostos de TosilRESUMO
The purpose of the investigation was to study the course of and the efficiency of treatment for new-onset infiltrative pulmonary tuberculosis. Two hundred and two patients with this condition were examined. Among the 202 patients, 15 (7.4%), 49 (24.3%), and 46 (22.8%) patients had lobular, rounded, and cloud-like infiltrates, respectively. 31 (15.3%) patients had periscissuritis and 61 (30.2%) had lobitis. The extent of infiltrative pulmonary tuberculosis within 1 segment was encountered in 19.3% and more frequently in the presence of rounded and lobular infiltrates; the specific process in 2 segments was detected in 24.3% of cases and more frequently when rounded and cloud-like infiltrates were observed. In periscissuritis and lobitis, the process occupied 1 lobe in 87.1 and 44.3% of cases, respectively, and 2 lobes or more in 34 (55.7%) patients. Infiltrates were located in the upper lobe in 167 (82.7%) patients, in Segment IV in 21 (10.4%), Segment IX in 6 (3%), Segment X in 5 (2.5%). The signs of lung tissue decay were detected in 140 (69.3%) persons. Decay cavities of less than 2 cm, 2-4 cm, and more than 4 cm in diameter were found in 56 (40%), 62 (44.3%), and 22 (15.7%) patients, respectively. Mycobacterium tuberculosis (MTB) was detected in 13.3, 46.9, 54.4, 70.9, and 83.6% of the patients who had lobular, rounded, and cloud-like infiltrates, periscissuritis, and lobitis, respectively. The drug-sensitive MBT population was seen in 58.4% of the patients; the drug-resistant MBT population was detected in 18.1% of the patients: in 14.3% with a lobular infiltrate, in 10% with a rounded infiltrate, in 28.6% with a cloud-like one, in 21.4% with perscissuritis, and in 15.7% with lobitis. Multi-drug MBT resistance was ascertained in 3.5% of the patients. Bacterial isolation ceased in 100% of the patients with a lobular infiltrate after 1-month therapy, in 47.8 and 52.2% of those with a rounded infiltrate after 1- and 2-month therapy, respectively, in two thirds and one third of the patients with a cloud-like infiltrate after 1- and 2-month therapy, respectively, in 45.4 and 31.8% of those with periscissuritis after 1- and 2-month therapy, respectively, and in 45.1 and 11.8% of cases of lobitis after 1- and 4-month therapy, respectively.
Assuntos
Antituberculosos/uso terapêutico , Brônquios/fisiopatologia , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/fisiopatologia , Adulto , Brônquios/microbiologia , Exsudatos e Transudatos/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Sons Respiratórios , Índice de Gravidade de Doença , Resultado do Tratamento , Tuberculose Pulmonar/microbiologiaRESUMO
Epidemiological studies suggest that serum calcidiol (25(OH)-Vitamin D3) seems to be associated with several cancers including prostate cancer. We have made several experimental studies in order to clarify the mechanism(s) involved in the association. Calcidiol has been regarded as an inactive prohormone for calcitriol, which possesses the highest biological activity of the Vitamin D metabolites, when it is evaluated on the basis of bioactivity/nmol. However, we found recently that at the physiological concentration calcidiol (100-200 nM) is an active hormone, whereas calcitriol (1alpha,25(OH)2-Vitamin D3) (100 pM) is inactive in human primary prostate stromal cells. Calcidiol is able to inhibit cell growth and to induce or inhibit several genes including 1alpha-hydroxylase and 24-hydroxylase genes. This suggests that calcidiol might be an independent endocrine system involved in the control of cell differentiation and proliferation, whereas calcitriol might be mainly involved in the regulation of calcium and phosphorous balance. Several mechanisms may mediate the action of Vitamin D in the prostate. This is a review of some recent studies on the role of (1) Vitamin D metabolism, (2) growth factors and (3) fatty acid metabolism.
Assuntos
Calcifediol/metabolismo , Neoplasias da Próstata/metabolismo , Calcitriol/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Ácidos Graxos/metabolismo , Substâncias de Crescimento/metabolismo , Humanos , Masculino , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/etiologia , Neoplasias da Próstata/patologia , Transdução de Sinais , Deficiência de Vitamina D/complicaçõesRESUMO
Real-time RT-PCR using fluorescence dyes (e.g. SYBR Green I) is currently the most sensitive and precise method for investigation of RNA level and has long been widely used for absolute and relative quantification of mRNA in the cell. This highly sensitive method allows measurement of different type RNA level in the cell based on the kinetics of the corresponding double-stranded cDNA amplification. Upon its binding to the minor groove of double-stranded DNA, SYBR Green I dye increases its fluorescence about 100-fold, and this increase can be recorded even at early cycles of amplification. During the real-time RT-PCR procedure the level of amplified DNA is measured after every cycle of amplification, which permits to perform quantification at the cycles when amplification curve has not yet reached the "plateau" range and corresponds to the range of exponential increase in DNA amount. This approach makes it possible to avoid misinterpretation of data typical of conventional PCR methods "in the end point" and caused by a deficiency of one or more reaction components at the late PCR cycles. We applied for the first time real-time RT-PCR using SYBR Green I for the measurement of the class III genes RNA-product level, that is, small stable non-translated RNAs--ribosomal 5S rRNA, initiator transfer RNAiMet1, and Alu-RNA, synthesized by DNA-dependent RNA polymerase III. We investigated the level of 5S rRNA-, tRNA- and Alu-gene expression in the cell being in different states: with prolonged generation period, activated to proliferation, and apoptotic. The expression level was judged from the content of corresponding RNA-products in the total cellular RNA. The used approach enabled us to find out the specific RNA share in the total cell RNA. Human epidermoid carcinoma cells A431 were used as a model for investigating class III gene expression level in vivo. These cells expose on their surface an abnormally large amount of receptors to epidermoid growth factor (EGF), and the result of EGF action on A431 cells depends on the growth factor concentration. Low concentrations of EGF (0.1 ng/ml) cause active proliferation of A431 cells, but its high concentrations (10-100 ng/ml) cause apoptosis in these cells. Besides, upon growing in serum-free media, A431 cells continue to proliferate, but by this extending the generation period to 48 h, against 30 h on growing in serum-containing media. Hence, A431 cells can serve as a useful model for investigation of specific gene expression level in cells being in different physiological states, in both slowly and actively proliferating cells, and in apoptotic cells. For successful use of real-time RT-PCR in 5S rRNA, tRNAi(Met)1 and Alu-RNA level quantification, we optimized the amplification reaction conditions. We took into account that the share of each particular RNA in the cell may vary--the share of ribosomal RNA is high, tRNAi(Met)1--low, and Alu-RNA--very low. Moreover, the level of some small RNAs (e.g. Alu-RNA) can vary significantly in cells of different lines. This explains why the amount of cDNA, gained by reverse transcription of total cellular RNA, and the concentration of specific primers used for PCR were different in each case. We showed that the expression of different class III genes--5S rRNA-, tRNA- and Alu-genes, was not similarly regulated in response to external stimuli, causing prolongation of generation period, activation of proliferation and apoptosis. 5S rRNA level was practically the same in A431 cells both having prolonged generation period and being activated by EGF in low concentration, but in apoptotic cells this level dramatically fell about 8-fold. Alu-RNA level was equal in cells with prolonged generation period and in apoptotic cells, and increased about 2-fold in cells activated by EGF in low concentration. The initiator tRNAi(Met)1 level in cells activated by EGF in low concentration and in apoptotic cells was by almost two times higher than in cells with prolonged generation period. The data obtained testify that the real-time RT-PCR method using SYBR Green I yields highly reliable and reproducible quantification for the level of class III gene RNA-products--small stable RNAs (5S rRNA, tRNA and Alu-RNA). Examination of each specific RNA level requires individual selection for the amplification reaction conditions: the amount of cDNA and primer concentration in the sample. This is primarily caused by different expression levels in some particular class III genes within the frames of the cells, and by different levels of some small stable RNAs (e. g. Alu-RNA) in different cell lines. Special attention must be paid to the internal control for discriminating between specific RNA levels in proliferating and apoptotic cells, as in the late apoptosis RNAs of most types are degraded (for example, mRNA of "house-keeping" gene for RPLP0 protein, used as a possible internal control in our experiments). As far as the applied approach allows estimation of a specific RNA share in the total cellular RNA, we propose to chose as internal control mRNA, whose share doesn't change during the total RNA degradation in apoptosis and thus, mRNA degradation is not selective (in relation to other type RNAs). In that way, the real-time RT-PCR method, which is currently the most sensitive and precise method for quantification of RNA in the cell, holds much promise for the investigation of not only different mRNAs, but also small stable RNAs, synthesized by RNA polymerase III.
Assuntos
Linhagem Celular Tumoral/metabolismo , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/metabolismo , RNA/metabolismo , Elementos Alu , Apoptose , Benzotiazóis , Diaminas , Estudos de Avaliação como Assunto , Corantes Fluorescentes , Humanos , Compostos Orgânicos , Quinolinas , RNA/análise , RNA Antissenso/análise , RNA Antissenso/metabolismo , RNA Mensageiro/análise , RNA Ribossômico 5S/análise , RNA Ribossômico 5S/metabolismo , RNA Interferente Pequeno , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Inducible hormone-dependent tryptophan oxygenase gene is expressed mostly in the liver under the control of glucocorticoid hormones. In the regulatory region of this gene there are three constitutive sites independent of hormone presence and gene expression. While investigating transcription factors responsible for the formation of specific chromatin structure in the regulatory region of inducible genes it is necessary to identify proteins which can bind to DNA specifically in these sites. The present paper reports investigation of transcription factors which bind to DNA from the -292nd to the -178th nucleotide of gene to in vitro. This DNA region contains a site corresponding to the constitutive DNase I hypersensitive site in vivo. Using electrophoretic mobility shift assay, we have analysed binding of rat liver proteins to this DNA region. NF1-rich nuclear protein fraction was purified from the rat liver nuclear extract by DEAE-cellulose and heparin-sepharose chromatography. Studies of the competition with a consensus sequence site for NF1 recognition sites have shown that it is the NF1 family transcription factors that are responsible for the formation of these specific complexes.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Sequências Reguladoras de Ácido Nucleico , Fatores de Transcrição/metabolismo , Triptofano Oxigenase/genética , Animais , Fígado/metabolismo , Fatores de Transcrição NFI , Ligação Proteica , RatosRESUMO
The level of 5S rRNA and tRNAi(Met)1 synthesized by RNA polymerase III was investigated in human epidermoid carcinoma cells A431 at different physiological states: low and high proliferation and apoptosis. The real-time RT-PCR method using SYBR Green I was applied to measure certain RNA species in total cellular RNA. The share of 5S rRNA was practically the same in slowly and actively proliferating A431 cells, but increased about 2.5-fold in apoptotic cells. The share of initiator tRNAi(Met)1 in actively proliferating and apoptotic cells was 1.5-2.0 times higher than in slowly proliferating cells. Our results suggest a possible existence of special mechanisms regulating RNA polymerase III-directed transcription from different type promoters in accordance with the physiological state of the cell.
Assuntos
Apoptose , Divisão Celular/fisiologia , RNA Polimerase III/fisiologia , RNA Mensageiro/análise , RNA Ribossômico 5S/análise , Linhagem Celular Tumoral , Humanos , RNA de Transferência de Metionina/análise , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
It is shown that BR and intermediate products of its phototransformation P600, P550 and P415 (the maximum at -196 degrees C at 419 nm) are not paramagnetic. Illumination of samples containing P415 (P419) at -- 196 degrees C with light in the region of 360-480 nm results in the formation of paramagnetic centres with a sunglet spectrum deltaH=18 Oe and g=2.002 (R1). In parallel formation of a new photoproduct P421 in the absorption spectrum is observed. During subsequent heating at -140 degrees C formation of an asymmetric signal with deltaH=45 Oe and g=2.006 and g=2.03 was observed. In the absorption spectra a dark transition. P421-P565 was observed under the same conditions. P565 differs from initial BR P570 as to its photochemical properties. R1 is identified as retinal radical, R2 as a peroxide radical of the BR-complex lipids. Paramagnetic, spectral, and photochemical properties of some products of BR transformation are compared. A scheme of oxidative-phosphorylation processes with participation of Mn ions in BR phototransformation.
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Bacteriorodopsinas/metabolismo , Carotenoides/metabolismo , Halobacterium/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Luz , Análise EspectralRESUMO
Effect of constant magnetic field (CMF) with induction 10 T on membrane preparations of Na,K-dependent ATPase of bovine brain (lipoproteid vesicules with 300-500 A diameter) were studied. No CMF effect on the activity of Na,K-dependent ATPase was observed under different experimental conditions (three temperature points 15, 20 and 37 degrees C and great variation of Na+,K+ concentrations ratio). CMF also produced no effect on the preparations of Na,K-dependent ATPase immobilized by adsorption on millipore filters.
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Magnetismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Encéfalo/enzimologia , Bovinos , Técnicas In Vitro , Membranas/enzimologiaRESUMO
It has been found that some macrocyclic esters have no ionophoric properties, but can block valinomycin-induced potassium transport in mitochondrial membranes and lessen the potassium current induced by valinomycin in phosphatidylcholine bilayers. It has been also discovered that 36-member cyclic esters of succinic acid and propylene glycoles decrease fluorescence of puridine nucleotides in mitochondria and produce a modifying effect on bimolecular phosphatidylcholine membranes in the medium of litium, calcium and magnesium chlorides at unilateral injection. The results obtained suggest that cyclopolyesters under investigation form mixed complexes with the macromolecules in the composition of mitochondrial and phosphatidylcholine membranes with the participation of the integrated ion.
Assuntos
Membranas Intracelulares/metabolismo , Bicamadas Lipídicas , Mitocôndrias Hepáticas/metabolismo , Fosfatidilcolinas , Potássio/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Cátions , Cinética , Ratos , Valinomicina/farmacologiaRESUMO
To test probable effect of the magnetic field (MF) on the dynamic structure of globular proteins the action of strong MF on proteolysis rate of methemoglobin and serum albumin with trypsin was studied. It has been found that the MF up to 10 T does not affect the proteolysis rate of these proteins and does not effect that of serum albumin with immobilized trypsin. This makes impossible consideration of the effect on the dynamic structure of globular proteins as a mechanism of the MF action on biological systems.
Assuntos
Metemoglobina , Conformação Proteica , Albumina Sérica , Tripsina/metabolismo , Humanos , Hidrólise , Cinética , MagnetismoRESUMO
A comparative analysis of new macrocyclic amidoesters effect on the bimolecular lipid membrane as well as on the electroexcitable membrane of snail isolated neurons was carried out. It was shown that the investigated complexes inducing a small change in lipid bilayer conductivity and some changes in Na-Ca neuron current characteristics produce essential changes of rapid potassium as well as late potassium current properties. It was concluded on the basis of these results and potassium compounds specificity that the investigated complexes interact directly with neuron potassium channels.