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1.
Acta Chir Orthop Traumatol Cech ; 91(1): 17-23, 2024.
Artigo em Tcheco | MEDLINE | ID: mdl-38447561

RESUMO

PURPOSE OF THE STUDY: Spine stabilization surgery is nowadays one of the most common spinal surgical procedures. Spinopelvic alignment is considered to be an important factor impacting the patients' preoperative diffi culties as well as the outcome of surgery. In our study, the outcomes of stabilization surgeries in patients with lumbar spine disorders were evaluated - especially in those with stenosis and spondylolisthesis, in whom the importance of sagittal parameters were assessed with respect to the patients' clinical outcomes and diffi culties. MATERIAL AND METHODS: The study included 50 patients with lumbar spine disorders who had undergone a spine stabilization surgery for a degenerative disease - lumbar spinal stenosis, spondylolisthesis between 2015 and 2017. Spino-pelvic radiological parameters and clinical parameters were evaluated using the nonparametric Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests. RESULTS: In 38 of 50 patients, who at the end of the follow-up period did not have the PI-LL (pelvic incidence-lumbar lordosis) mismatch, i.e. PI-LL was ≤10°, a statistically signifi cant difference in pelvic tilt (p=0.049) and sagittal vertical axis (p<0.001) was reported, which was not the case in the remaining patients of the study population. Claudication and OSWESTRY (ODI) showed no statistically signifi cant difference. We have also compared the differences in the number of fused vertebrae and type of stabilization. A signifi cant change was seen in the claudication parameter at 12 and 24 months after surgery (p=0.007, p=0.005), with better outcomes achieved by 360° lumbar fusion compared to posterior lumbar fusion. The improvement of VAS and ODI scores in both the groups over time (from 6.1 to 3.6 or from 6.3 to 3.5 in VAS and from 62 to 32, or from 62 to 30 in ODI) was also statistically signifi cant (p<0.001 in both groups), while when comparing the groups against each other it was statistically insignifi cant. DISCUSSION: The authors confi rmed signifi cant improvement in the studied clinical parameters in all groups of patients (VAS, ODI, claudication), which is consistent with the results of recently published papers. The authors also established the correlation between different radiological parameters in the studied groups. The results do not confi rm the importance of the length or type of instrumentation for the clinical outcomes. This is consistent with the fi ndings of other published manuscripts. The authors failed to confi rm a signifi cant change in clinical parameters in dependence on the matching relationship between the pelvic incidence and lumbar lordosis. CONCLUSIONS: Proper spinopelvic balance in patients after spinal surgery is a very important indicator of postoperative development and condition, but our cohort showed no statistically signifi cant difference in the clinical outcomes of patients whose postoperative sagittal parameters were unsatisfactory. KEY WORDS: sagittal profi le, spine stabilization, pelvic tilt, pelvic incidence, sagittal vertical axis, SVA.


Assuntos
Lordose , Espondilolistese , Animais , Humanos , Espondilolistese/cirurgia , Coluna Vertebral , Marcha , Procedimentos Neurocirúrgicos
2.
Acta Chir Orthop Traumatol Cech ; 76(6): 501-4, 2009 Dec.
Artigo em Tcheco | MEDLINE | ID: mdl-20067698

RESUMO

PURPOSE OF THE STUDY: We present a group of patients with spinal metastatic disease surgically treated at our department, with an evaluation of their neurological outcomes in relation to the initial disease and the surgical technique used. MATERIAL: Between 1989 and 2007 we operated on 748 patients with spinal tumour. Of these, 380 had metastatic disease. The Frankel classification system was used to assess neurological status. METHODS: Based on the Tomita prognostic score, the metastatic disease was evaluated and appropriate surgical procedure was selected (biopsy, posterolateral decompression, posterolateral decompression with stabilisation, somatectomy, or vertebrectomy/spondylectomy). The neurological findings before and after surgery and at follow-up were assessed. RESULTS: Of the 368 patients evaluated, four were pre-operatively classified as Frankel grade A, 29 as grade B, 99 as grade C, 82 as grade D and 159 patients as grade E. Post-operative outcomes were: Frankel grade A, 6 patients B, 27 C, 78 D, 79 and E, 178 patients. Surgery resulted in neurological deterioration by 3 degrees of the Frankel scale in two patients (0.5%), 2 degrees in three patients (0.8%), and by 1 degree in 17 patients (4.6%). Improvement was recorded: by 1 degree in 57 patients (15.5%), 2 degrees in 10 (2,7%) and 3 degrees in two patients (0.5%). Of 23 patients who underwent biopsy, neurological status improved in one (4.3%) and deteriorated also in one patient (4.3%). Of the 85 patients treated by posterolateral decompression, improvement was recorded in 25 (29.4%) and deterioration in two (2.4%). Of the 73 patients undergoing posterolateral decompression with stabilisation, neurological findings improved in 15 (17.9%) and deteriorated in five (6.0%). In the group of 103 patients treated by vertebrectomy, neurological findings improved in 13 (12.6%) and deteriorated in eight (7.8%). At an average follow-up of 15 months, 208 (55.7%) patients presented themselves of these, improvement in neurological status was recorded in 16 (7.8%) and deterioration in eight (3.9%), as compared with the pre-operative values. DISCUSSION: Any comparison with the literature data is difficult, because both the criteria of indication for surgery and the method of treatment differ considerably. Improvement in neurological status was achieved in 69 patients (18.8%). CONCLUSIONS: Metastatic tumours of the spine present a serious diagnosis, with pain often being the first sign of a malignant disease. The degree of neurological deficit, primary tumour site and the extent of metastatic spinal disease (objectively evaluated on the basis of the Tomita score) should determine whether the patient will be operated on or not and, if so, whether a radical or mere palliative procedure will be used. An important factor is multidisciplinary cooperation of attending physicians both preoperatively and during the post-operative care of cancer patients.


Assuntos
Doenças do Sistema Nervoso/etiologia , Neoplasias da Coluna Vertebral/secundário , Neoplasias da Coluna Vertebral/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/diagnóstico , Neoplasias da Coluna Vertebral/fisiopatologia , Adulto Jovem
3.
Acta Chir Orthop Traumatol Cech ; 75(3): 180-4, 2008 Jun.
Artigo em Tcheco | MEDLINE | ID: mdl-18601815

RESUMO

PURPOSE OF THE STUDY: In a retrospective study, to analyze long-term radiographic results of two surgical procedures used to treat congenital scoliosis. MATERIAL AND METHODS: A total of 685 patients with congenital scoliosis were treated at the Department of Orthopaedic Surgery, Bohunice Teaching Hospital in Brno, between 1976 and 2007. Of these, 102 patients, with an average age of 6.6 years at the time of surgery, were treated by simple bony fusion, and 22 children, with an average age of 10.2 years, underwent instrumented hemivertebra excision via simultaneous anterior and posterior exposures involving fixation with cannulated compression screws and a wire loop. The follow-up periods for the former and latter groups were 14.2 and 12.1 years, respectively. RESULTS: In the patients treated by simple bony fusion, the mean correction rate was 22.1 %, with Cobb angle values averaging from 44.2 degrees pre-operatively to 38 degrees post-operatively; the correction loss was 3.9 degrees at the last follow up. In the patients with hemivertebra excision, the mean correction rate was 61 %, with pre- and post-operative values of 51.3 degrees and 20.3 degrees , respectively, and a correction loss of 1.1 degrees at the last follow-up. DISCUSSION: The early detection of a deformity and simple bony fusion in low-magnitude curves can prevent progression of scoliosis and allows for maintenance of a compensated spine. Hemivertebra excision with compression instrumentation results in a better surgical correction of the deformity. The average 61 % correction rate achieved in our patients is in agreement with the results reported by authors using the same surgical technique, as well as with the results of posterior hemivertebra resection. The best correction, 78 %, has been achieved with surgery at a very young age. Complications associated with the two techniques are rare. CONCLUSIONS: Congenital scoliosis due to failure off either formation or segmentation is indicated for surgical treatment at young age. Its early detection and subsequent surgical treatment at young age. Its early detection and subsequent surgical correction of the curve result in a long-term maintenance of a compensated spine. Instrumented hemivertebra excision provides the highest rate of correction, particularly if carried out before 3 years of age.


Assuntos
Vértebras Lombares/cirurgia , Escoliose/congênito , Escoliose/cirurgia , Fusão Vertebral , Vértebras Torácicas/cirurgia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Radiografia , Escoliose/diagnóstico por imagem
4.
J Proteomics ; 140: 55-61, 2016 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-27063990

RESUMO

UNLABELLED: Although several new biomarkers have been recently proposed for psoriasis (Ps) and psoriasis arthritis (PsA), nothing is known about their diagnostic sensitivity and specificity, and their routine use. We therefore searched in-depth for new biomarker candidates using a biobank with EDTA-plasma from 158 individuals, patients and healthy controls. Samples from 6 selected pairs (patients against healthy controls) were searched proteomically using a workflow of extensive and precise design that is highly comprehensive. Subsequent verification was performed using ELISA and the entire biobank. By proteomic methods, 208 altered proteins were identified. Of these, 15 biomarker candidates were selected for verification. Of these 15, 4 individual parameters and 11 combinations significantly discriminated between patient and control groups. These individual parameters were Zn-α2-glycoprotein, complement C3, polymeric immunoglobulin receptor, and plasma kallikrein. Significant discrimination was obtained by combinations of 2 or 3 parameters. One combination seemed suitable for diagnosing PsA. Moreover, several candidates desmoplakin, complement C3, polymeric immunoglobulin receptor, and cytokeratin 17, correlated with PASI in all patients. This first comprehensive proteomic study on non-depleted plasma identified several biomarker candidates that have not been described before as well as some known from previous studies. BIOLOGICAL SIGNIFICANCE: Our non-gel proteomic analysis is based on the highly comprehensive and significantly optimized chromatographic protein pre-fractionation. The method allows a biomarker search in non-depleted plasma. The subsequent verification by ELISA identifies several biomarker-candidates for the unbiased diagnosis of psoriasis and psoriasis arthritis. Four of the identified candidate markers might be used individually. Combinations of several parameters improve the diagnostic sensitivity and specificity. The still not validated candidates form a reserve for further evaluation. Moreover, mass spectrometric data uncover several biomarker-candidates which show diverse protein species of the same protein with opposing changes in the same sample.


Assuntos
Artrite Psoriásica/diagnóstico , Proteômica/métodos , Psoríase/diagnóstico , Adulto , Artrite Psoriásica/sangue , Biomarcadores , Estudos de Casos e Controles , Complemento C3/análise , Desmoplaquinas/sangue , Feminino , Glicoproteínas/sangue , Humanos , Queratina-17/sangue , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Calicreína Plasmática/análise , Psoríase/sangue , Receptores de Imunoglobulina Polimérica/sangue
5.
Cent Eur J Public Health ; 13(3): 153-8, 2005 09.
Artigo em Inglês | MEDLINE | ID: mdl-16218333

RESUMO

Mining for coal and its utilization have various impacts on the surrounding environment. Huge volumes of waste materials which are by-products of both the underground and open cast coal mining, pose one of the major environmental hazards in addition to air pollution caused by coal burning in power plants in the Czech Republic. Some of these risks could be reduced when having accurate and comprehensive data on coal quality. Statistical data processing of almost 35,000 coal samples from Late Paleozoic and Tertiary coal basins of the Czech Republic provided a unique information on the quality of lignite, sub-bituminous and bituminous coals and anthracites including the content of toxic trace elements (As, Be, Hg, Pb and Se). In this context related environment and health risks and protection implications are discussed.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Carvão Mineral/efeitos adversos , Exposição Ambiental/efeitos adversos , Oligoelementos/efeitos adversos , Poluentes Atmosféricos/análise , Arsênio/efeitos adversos , Arsênio/análise , Berílio/efeitos adversos , Berílio/análise , Carvão Mineral/análise , República Tcheca , Exposição Ambiental/estatística & dados numéricos , Humanos , Chumbo/efeitos adversos , Chumbo/análise , Mercúrio/efeitos adversos , Mercúrio/análise , Centrais Elétricas , Selênio/efeitos adversos , Selênio/análise , Oligoelementos/análise
6.
J Endocrinol ; 156(1): 67-75, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9496235

RESUMO

The purpose of this study was to determine the relationship between genetic selection for growth traits and tissue expression of the chicken growth hormone receptor (cGHR) gene. Two different populations of broiler chickens were studied. One population consisted of strain (S) 80, selected for 14 generations for high 9-week body weight (BW), and its progenitor, S90 (a 1950's strain). The second population consisted of S21, selected for 10 generations for high 4-week BW and low abdominal fat, and its progenitor S20 (a 1970's strain). Tissue (liver, fat, breast and leg muscle) and blood samples were collected from six birds/strain at 2-week intervals between 1 and 11 weeks of age. An RNase protection assay was developed to measure mRNA levels of full-length cGHR (3.2 and 4.3 kb) transcripts and chicken glyceraldehyde 3-phosphate dehydrogenase (for normalization) in total RNA prepared from tissue. Analysis of the area-under-curve (AUC) was used for strain comparisons of certain developmental profiles (BW, plasma hormones and tissue cGHR mRNA). The BW AUC showed that the growth rates are different (P < 0.05) among the four strains (S21 > S20 > S80 > S90). Both slow-growing strains (S90 and S80) had a higher (P < 0.05) plasma GH AUC than the two fast-growing strains (S20 and S21). The plasma T3 AUC was highest (P < 0.05) in S90 due to maintenance of higher T3 levels after 3 weeks of age. At 11 weeks of age, hepatic and plasma GH-binding activities were positively related to growth rate (S21 > S20 > S80 > S90). However, the developmental increase in cGHR mRNA in liver and fat was similar among these different populations of growth-selected broiler chickens. Steady-state levels of cGHR mRNA increased in a developmental manner in the liver (5-fold at 9 weeks of age) and abdominal fat (4.5-fold at 11 weeks of age) of all strains. In contrast, there was no developmental increase or strain difference in cGHR mRNA levels in breast and leg muscle. There is a discrepancy between GH-binding activity in liver and plasma, which is different among strains, and steady-state levels of tissue cGHR mRNA which are similar among strains. These observations suggest that the cGHR is under translational or post-translational regulation which would determine the amount of cGHR protein available for GH binding.


Assuntos
Tecido Adiposo/metabolismo , Galinhas/crescimento & desenvolvimento , Fígado/metabolismo , Receptores da Somatotropina/genética , Abdome , Animais , Área Sob a Curva , Autorradiografia , Galinhas/genética , Hormônio do Crescimento/sangue , Músculo Esquelético/metabolismo , RNA Mensageiro/análise , Especificidade da Espécie , Tri-Iodotironina/sangue
7.
Metabolism ; 49(11): 1424-30, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11092505

RESUMO

Lipoprotein and apolipoprotein changes were evaluated in 10-week-old Zucker diabetic fatty (ZDF) male rats following 12 weeks of insulin treatment, which normalized blood glucose and maintained weight gaining characteristic of nondiabetic Zucker fatty rats. Compared with untreated ZDF rats (saline-injected), insulin treatment resulted in increased very-low-density lipoprotein (VLDL; d < 1.006 g/mL) and decreased alpha lipoprotein on agarose gel electrophoresis. These findings were consistent with an observed increase in VLDL triglyceride and cholesterol, and decreased high-density lipoprotein (HDL) cholesterol with insulin treatment in isolated lipoproteins. B100 levels were unchanged by insulin treatment, but B48 levels were significantly increased in the VLDL fraction. Insulin treatment depressed apolipoprotein (apo) A-I levels in HDL, but had little effect on total apo E, apo A-IV, or apo C, although apo C was redistributed to the VLDL fraction. These results suggest that insulin treatment of ZDF rats normalizes hyperglycemia and prevents age-related changes in lipoprotein parameters associated with development of insulinopenic diabetes. Insulin therapy in ZDF rats thereby sustains the hyperlipidemic lipoprotein pattern associated with hyperinsulinemia and obesity.


Assuntos
Hipertrigliceridemia/complicações , Insulina/administração & dosagem , Obesidade/complicações , Animais , Glicemia/análise , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Hiperinsulinismo/sangue , Hiperinsulinismo/complicações , Hipertrigliceridemia/sangue , Lipoproteínas/sangue , Lipoproteínas/classificação , Lipoproteínas/isolamento & purificação , Masculino , Fenótipo , Ratos , Ratos Zucker
8.
J Chromatogr A ; 736(1-2): 255-64, 1996 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-8673248

RESUMO

A new method of electrochromatography is described in which a 50-microns capillary is etched with ammonium hydrogen difluoride, followed by modification of the new surface via a silation reaction with triethoxysilane to produce a hydride intermediate, and then subsequently subjected to hydrosilation using 1-octadecene in the presence of a platinum complex catalyst. The C18 bonded phase is then compared with bare capillaries, etched bare capillaries and the hydride etched capillary to determine if any solute-bonded phase interactions are present. With bradykinin as a test solute, peak efficiencies are quite similar for all capillaries without C18 but become noticeably broader when the organic moiety is attached to the etched capillary wall. A test mixture of peptides and proteins displays shorter retention for some of the components when methanol is added to the mobile phase which is typical of reversed-phase behavior. The same result is also obtained when a mixture of tetracyclines is separated on the C18 capillary with and without methanol as part of the mobile phase. The reproducibility of retention times for two proteins is +/- 1.5%. A few results for several neutral compounds indicate small but measurable k' values.


Assuntos
Cromatografia Líquida/métodos , Cromatografia Líquida/instrumentação , Eletroquímica , Microscopia Eletrônica de Varredura , Peptídeos/isolamento & purificação , Proteínas/isolamento & purificação , Reprodutibilidade dos Testes , Dióxido de Silício/química
9.
J Chromatogr A ; 736(1-2): 313-20, 1996 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-8673251

RESUMO

Separations of various tetracycline mixtures by high-performance capillary electrophoresis (HPCE) and a new form of electrochromatography (CEC) are compared. The new CEC method involves etching the inner wall of the capillary surface with an appropriate reagent (ammonium dihydrogen fluoride) in order to produce a significant increase in surface area. The etched surface is then modified by a silation/hydrosilation reaction sequence to first produce a hydride intermediate which is then further reacted to attach a C18 moiety. The bare and hydride capillaries are tested under HPCE conditions while the C18 capillary functions in the CEC mode. The effects of pH and the presence of an organic modifier (methanol) are also studied. Detection limits ( < 10 micrograms/ml) are comparable to previous HPLC and HPCE results. Resolutions for mixtures which simulate real analytical problems are equal to or better than those reported for separations on polymeric and diol columns by HPLC and in earlier studies by HPCE and MECC.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Tetraciclinas/isolamento & purificação , Eletroquímica
10.
J Chromatogr A ; 887(1-2): 31-41, 2000 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-10961302

RESUMO

This review describes an open tubular approach to capillary electrochromatography (OTCEC) that first etches the inner surface of the fused-silica tube using ammonium hydrogen diflouride. This process can increase the inner surface area significantly. The new surface is then chemically modified to attach a bonded stationary phase using a silanization/hydrosilation reaction process. The surfaces are characterized spectroscopically by diffuse reflectance infrared Fourier transform and by electroosmotic flow measurements. Applications of OTCEC columns with C18, diol and chiral stationary phases are described.


Assuntos
Eletroforese Capilar/métodos , Grupo dos Citocromos c/análise , Eletroforese Capilar/instrumentação , Muramidase/análise , Dióxido de Silício/química
11.
J Chromatogr A ; 763(1-2): 307-14, 1997 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-9129328

RESUMO

This study involves the evaluation of a capillary electrochromatography method based on etching the inner walls of a fused-silica tube, which is subsequently modified by a silanization/hydrosilation reaction scheme. Two different organic moieties, octadecyl and diol, are attached to the etched capillary wall. The performance of these two columns is compared to a bare capillary using peptide (angiotensins) and protein samples. It is concluded that the etching process increases the surface area of the inner wall sufficiently to induce solute-bonded phase interactions for the capillaries modified with the octadecyl and diol moieties. The separation capabilities of the two modified capillaries are not the same, presumably due to differences in the chemical properties of the two ligands. When compared to a bare capillary where separation is due only to electrophoretic mobility effects, the bonded etched capillaries also exhibit significant differences in separation factors for the same solutes under identical experimental conditions.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Peptídeos/isolamento & purificação , Proteínas/isolamento & purificação , Angiotensina I/isolamento & purificação , Angiotensina II/isolamento & purificação , Angiotensina III/isolamento & purificação , Grupo dos Citocromos c/isolamento & purificação , Concentração de Íons de Hidrogênio , Muramidase/isolamento & purificação , Mioglobina/isolamento & purificação , Ribonuclease Pancreático/isolamento & purificação , Silanos , Propriedades de Superfície
12.
J Chromatogr A ; 845(1-2): 237-46, 1999 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-10399338

RESUMO

Fused silica capillaries with an I.D. of 20 microns are etched and then chemically modified by the silanization/hydrosilation method to attach an octadecyl moiety for use in electrokinetic chromatography. The etched capillaries after chemical modification are shown to have an anodic electroosmotic flow below pH 4.5. In comparison to bare 20 microns capillaries and unetched but chemically modified 20 microns capillaries, the etched C18 fused silica tubes show better separation of mixtures of lysozymes and cytochrome c's under identical conditions of buffer, pH and applied voltage. It was also demonstrated that this open tubular approach to capillary electrochromatography was amenable to a number of different types of basic compounds ranging in size from typical small amines to biomolecules. As expected, pH is an important variable that must be controlled in order to obtain an optimized separation. Reproducibility studies verify the stability of the silicon-carbon linkage produced in this modification method so that column lifetimes of at least 300 injections can be expected.


Assuntos
Cromatografia/instrumentação , Cromatografia/métodos , Proteínas/isolamento & purificação , Ação Capilar , Grupo dos Citocromos c/isolamento & purificação , Eletroquímica , Concentração de Íons de Hidrogênio , Muramidase/isolamento & purificação , Osmose , Reprodutibilidade dos Testes , Dióxido de Silício
13.
J Chromatogr A ; 887(1-2): 497-503, 2000 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-10961337

RESUMO

The presence of the carcinogenic N-nitrosodiethanolamine (NDELA; CAS No. 1116-54-7) in cosmetic samples was determined using an etched, C18 modified capillary in the open-tubular capillary electrochromatography technique. A very simple extraction procedure leads to a sample matrix free from interferences. The calibration curve was created using UV detection at 214 nm. The detector response was linear in the range of 5-120 ppm total amount injected. Minimum detection limits (1 ppm NDELA injected on capillary) are suitable for screening a large number of cosmetic samples. Diethanolamine and triethanolamine precursors of nitrosamines are not detected at the wavelength used. Cosmetic samples were analyzed unspiked and after addition of 60 ppm of NDELA. In spiked samples recoveries varied from 94% (hand and body lotion) to 55% (lipstick sample). NDELA was found in unspiked samples of old (5-15 years old) cosmetics at concentrations of 14.0 ppm and 35.0 ppm.


Assuntos
Cosméticos/química , Dietilnitrosamina/análogos & derivados , Dietilnitrosamina/análise , Eletroforese Capilar/métodos , Contaminação de Medicamentos , Concentração de Íons de Hidrogênio , Espectrofotometria Ultravioleta/métodos
14.
J Chromatogr A ; 853(1-2): 151-8, 1999 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-10486721

RESUMO

The inner walls of 50 microns fused-silica capillaries are etched by ammonium hydrogendifluoride and then modified by the silanization/hydrosilation method with a chiral selector. Three different types of selectors were evaluated: lactone, beta-cyclodextrin and naphthylethylamine. Each of the bonded chiral stationary phases provided at least partial separation for one type of racemic solute. These results confirm that bonded organic moieties on the etched inner wall of a capillary can provided sufficient solute-bonded phase interactions to influence the retention of molecules driven through a capillary by electroosmosis or a combination of electroosmosis and electrophoretic mobility.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , beta-Ciclodextrinas , Ciclodextrinas/química , Estudos de Viabilidade , Lactonas/química , Peptídeos/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Estereoisomerismo
15.
J Chromatogr A ; 883(1-2): 55-66, 2000 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-10910200

RESUMO

The temperature effect on the separation of fullerenes in LC was examined using monomeric type C30, C18 and C8 alkyl bonded stationary phases. It appears that the C30 phase exhibits superior separation ability for fullerenes. It is observed that the maximum retention temperature of fullerenes on the C30 phase is around 20 degrees C. A strong correlation between the changes in NMR spectra and the retention behavior of the solutes was found. The interpretation of the retention behavior of fullerenes on the alkyl bonded stationary phases, including the behavior in subambient temperature, is discussed using the information obtained by CP-MAS solid-state NMR spectroscopy and LC.


Assuntos
Carbono/isolamento & purificação , Cromatografia Líquida de Alta Pressão/instrumentação
16.
J Chromatogr A ; 924(1-2): 211-21, 2001 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-11521867

RESUMO

In this investigation, various capillary electrochromatographic (CEC) experiments have been employed to characterize the properties of etched, chemically-modified surfaces of open tubular capillary columns with peptides as solute probes and under conditions of variable voltage, temperature and solvent composition. The separation performance of etched capillaries with either n-octadecyl or liquid crystal moieties derived from a cholesterol phase bonded to the surface were compared. With the liquid crystal bonded species, interesting and significantly different variations in retention behavior of peptides are obtained compared to those observed with the corresponding n-octadecyl modified surfaces by changes in temperature, solvent composition and field strength. These peptide separations illustrate the usefulness of this CEC approach for practical applications, where both the retention characteristics of the charged analytes as well as the selectivity differences due to the surface properties of the etched chemically-modified surfaces of open tubular capillary columns can be rationally modulated. As in HPLC, appropriate choice of CEC experimental variables, including the chemical properties of the immobilized ligand(s), represents a powerful tool for optimizing resolution.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/instrumentação , Peptídeos/química , Peptídeos/isolamento & purificação , Solventes , Temperatura
17.
J Chromatogr A ; 887(1-2): 479-87, 2000 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-10961335

RESUMO

Packed column capillary electrochromatography (CEC), open-tubular CEC and microcolum liquid chromatography (LC) using a cholesteryl silica bonded phase have been studied to compare the retention behavior for benzodiazepines. It has been found that packed column CEC gives better resolution, faster analysis time than microcolumn LC for benzodiazepines maintaining similar selectivity except for some solutes which are charged species under the separation conditions. However, open-tubular CEC gave different selectivities to a larger extent for charged benzodiazepines from that which should be produced by the chromatographic properties of the cholesteryl silica phase. Charged species migration times are mainly influenced by electrophoretic mobility rather than the chromatographic interactions.


Assuntos
Benzodiazepinas/isolamento & purificação , Eletroforese Capilar/métodos , Cromatografia Líquida/métodos , Fatores de Tempo
18.
J Inorg Biochem ; 32(4): 233-8, 1988 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3379392

RESUMO

The chemical shift changes observed in the carbon-13 NMR spectra of the carboxylate region in conjunction with previous fluorescence data indicate that mercury and lead bind to both disulfide bridge 64-80 and to Asp-52 in hen egg-white lysozyme. Methylmercury appears to bind primarily to the disulfide linkage. The carbon-13 NMR results support previous investigations by halide ion NMR and x-ray crystallography. The combined information from all of these techniques is useful for providing a clearer description of heavy metal binding to proteins.


Assuntos
Chumbo/metabolismo , Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Muramidase/metabolismo , Sítios de Ligação , Isótopos de Carbono , Dissulfetos , Espectroscopia de Ressonância Magnética/métodos , Ligação Proteica
19.
Talanta ; 39(10): 1215-8, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18965518

RESUMO

The secondary structure of purified protamine, a non-specific DNA binding protein, was studied in solution at pH 4, 7 and 8 by FTIR. This permitted analysis of the folded form of the protein (acidic pH) as well as the folded conformers (neutral and basic pH). Hg(2+) was utilized to probe the accessibility of the free thiol groups (cysteine residues). The SH groups form when disulfides, which play the major role in stabilizing the conformation of this protein, are broken. It was possible to observe different conformational states in protamine as a function of pH and the presence of Hg(2+) via spectral changes primarily in the amide region. The results lead to the conclusion that protamine is not completely folded under conditions similar to those found in vivo (37 degrees , neutral pH, phosphate buffer and high protein concentration).

20.
Drug Metabol Drug Interact ; 18(3-4): 159-90, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11791883

RESUMO

Powerful medicinal properties have been recorded for Zingiber officinale, commonly known as ginger. All of these medicinal activities have been compiled with 99 references to the present status of the plant in the literature. Volatile components and the presence of trace metals are included. In addition, details of individual medicinal activities are given and the molecular structures of identified organic metabolites and their synthesis are described.


Assuntos
Fitoterapia/métodos , Zingiber officinale/química , Anticolesterolemiantes/uso terapêutico , Antioxidantes/uso terapêutico , Antirreumáticos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Cromatografia Gasosa/métodos , Humanos , Extratos Vegetais/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Úlcera Gástrica/prevenção & controle , Oligoelementos/análise
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