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1.
Disabil Rehabil ; : 1-14, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39162074

RESUMO

PURPOSE: Ronnie Gardiner Method (RGM) is a music-based movement therapy that has long been used within rehabilitation. There is a need to (1) identify the scope of the use of RGM, (2) explore potential benefits, (3) examine qualitative studies to capture perspectives from participants and practitioners, and (4) identify knowledge gaps to be addressed in future research. MATERIALS AND METHODS: A scoping review methodology was conducted. PubMed, CINAHL, Scopus, as well as the search engines DIVA portal, Libris.se, Google Scholar, and uppsatser.se were searched. Quantitative studies were summarised using diagnosis as a differentiating criterion, and qualitative studies were summarised in a narrative synthesis. RESULTS: Twenty-three studies were included, the vast majority of which consisted of non-peer-reviewed publications/grey literature. There is initial research evidence on potential benefits for stroke rehabilitation, with inconclusive results in other populations. Qualitative data indicate that RGM is adequately challenging and motivating for participants, with positive perceptions of recovery and quality of life. CONCLUSIONS: Findings indicate that RGM could serve as a valuable addition to neurological rehabilitation. Potential benefits were identified, and qualitative data indicate that RGM is perceived as motivating and enjoyable. Future research should employ robust study designs, including controlled trials, to further validate RGM.


The Ronnie Gardiner Method addresses various recovery aspects, including mobility, cognition, and emotional well-being, providing a comprehensive intervention with multiple purposes.The Ronnie Gardiner Method can increase patient adherence and engagement in neurorehabilitation through its enjoyable and motivational aspects.The option of sitting down during the exercises, and the absence of adverse events, potentially makes the Ronnie Gardiner Method suitable for populations with special needs.Rehabilitation professionals are advised to exercise caution given the limited availability of well conducted trials.

2.
Sci Rep ; 8(1): 14000, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30228297

RESUMO

Photodynamic therapy uses photosensitizers (PS) to kill cancer cells by generating reactive oxygen species - like singlet oxygen (SO) - upon illumination with visible light. PS membrane anchoring augments local SO concentration, which in turn increases photodynamic efficiency. The latter may suffer from SO's escape into the aqueous solution or premature quenching. Here we determined the time constants of SO escape and quenching by target molecules to be in the nanosecond range, the former being threefold longer. We confined PS and dipolar target molecules either to different membrane monolayers or to the same leaflet and assessed their abundance by fluorescence correlation spectroscopy or membrane surface potential measurements. The rate at which the contribution of the dipolar target molecules to membrane dipole potential vanished, served as a measure of the photo-oxidation rate. The solution of the reaction-diffusion equations did not indicate diffusional rate limitations. Nevertheless, reducing the PS-target distance increased photodynamic efficiency by preventing other SO susceptible moieties from protecting the target. Importantly, our analytical model revealed a fourfold difference between SO generation rates per molecule of the two used PSs. Such analysis of PS quantum yield in a membrane environment may help in designing better PSs.

3.
J Pharm Biomed Anal ; 159: 262-271, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30005241

RESUMO

This review article is focused on element composition of medicinal plants and herbs as well as their decoctions and infusions determined by atomic spectrometry methods. Considering quality and safety of these herbal beverages, widely practiced in herbalism for medicinal and supplementing purposes, element analysis is important, and quality of its results should not raise any doubts about reliability. Hence, original researches devoted to element analysis of decoctions and infusions of medicinal plants and herbs, published after 2000, have been surveyed in details, particularly focusing on sources of elements in medicinal plants, their availability for the intake during preparation of infusions and decoctions as well as different methodological aspects related to element analysis by atomic spectrometry, including sample pretreatment and preparation before measurements, calibration methods used, and verification of reliability of results.


Assuntos
Medicina Herbária/métodos , Extratos Vegetais/análise , Plantas Medicinais , Espectrofotometria Atômica/métodos , Animais , Medicina Herbária/tendências , Humanos , Extratos Vegetais/química , Plantas Medicinais/química , Espectrofotometria Atômica/tendências
4.
J Photochem Photobiol B ; 161: 162-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27236238

RESUMO

Photosensitizers are widely used as photodynamic therapeutic agents killing cancer cells by photooxidation of their components. Development of new effective photosensitive molecules requires profound knowledge of possible targets for reactive oxygen species, especially for its singlet form. Here we studied photooxidation of voltage-sensitive styryl dyes (di-4-ANEPPS, di-8-ANEPPS, RH-421 and RH-237) by singlet oxygen on the surface of bilayer lipid membranes commonly used as cell membrane models. Oxidation was induced by irradiation of a photosensitizer (aluminum phthalocyanine tetrasulfonate) and monitored by the change of dipole potential on the surface of the membrane. We studied the drop of the dipole potential both in the case when the dye molecules were adsorbed on the same side of the lipid bilayer as the photosensitizer (cis-configuration) and in the case when they were adsorbed on the opposite side (trans-configuration). Based on a simple model, we determined the rate of oxidation of the dyes from the kinetics of change of the potential during and after irradiation. This rate is proportional to steady-state concentration of singlet oxygen in the membrane under irradiation. Comparison of the oxidation rates of various dyes reveals that compounds of ANEPPS series are more sensitive to singlet oxygen than RH type dyes, indicating that naphthalene group is primarily responsible for their oxidation.


Assuntos
Corantes/química , Bicamadas Lipídicas/química , Compostos de Piridínio/química , Oxigênio Singlete/química , Dimetil Sulfóxido/química , Eletricidade , Indóis/química , Lasers , Modelos Químicos , Compostos Organometálicos/química , Oxirredução , Fármacos Fotossensibilizantes/química , Espectrofotometria Ultravioleta
5.
Dalton Trans ; 44(46): 20067-74, 2015 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-26525418

RESUMO

A series of highly crystalline orthoferrite nanoparticles (type La(1-x)Gd(x)FeO3, where x = 0 to 1) were prepared using the self-combustion method. Extensive studies including X-ray diffraction, Rietveld refinement and Fourier transform infrared spectroscopy as well as Raman spectroscopy confirmed the orthorhombic space group Pnma of the obtained materials. The calculated average grain size for powders is in the range of 30 to 80 nm. Magnetic characterization of the La(1-x)Gd(x)FeO3 series, performed at 1.72 K, indicated an antiferromagnetic state characterized by some canting of iron magnetic moments, in good agreement with the data reported for similar fine-particle systems.

6.
Vet Parasitol ; 214(3-4): 322-6, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26255094

RESUMO

Anaplasma marginale is an obligate intracellular pathogen that infects the erythrocytes of calves, causing bovine anaplasmosis. This rickettsia is biologically transmitted by several species of ticks. In tropical and subtropical regions of the world, Rhipicephalus microplus is the main vector. Due to their mobility and longevity, the adult males play an important role in the transmission of A. marginale to calves. Some studies have demonstrated that A. marginale can be intrastadially and interstadially transmitted in R. microplus, but the transovarial transmission has not been demonstrated so far. In the present study, we investigated the effects of low temperature on both the A. marginale migration from infected females to their offspring and reproductive parameters of the tick R. microplus. The larvae of R. microplus fed on a calf infected with the strain Jaboticabal of A. marginale. At the end of the parasitic phase, fully engorged females were incubated at either 18°C or 28°C for oviposition. Although A. marginale was detected in the salivary glands of the females, demonstrating that the ticks were successfully infected, the presence of rickettsia was not detected in the offspring. However, the preoviposition period of the non-infected females maintained at 18°C was longer than that of those maintained at 28°C. In addition, the average weight of the mass of eggs as well as the egg production efficiency (ratio of the egg mass weight to the female weight) of the females maintained at 18°C were significantly lower than those of the females incubated at 28°C. There was no larval hatching from the eggs maintained exclusively at 18°C, even at 65 days after female detachment. Hatching occurred only when the eggs maintained at 18°C were transferred to 28°C at 20 days after female detachment (18°C/28°C). We also verified a significantly higher larvae conversion efficiency (ratio of the larvae mass weight to the egg mass weight) in the group of females maintained exclusively at 28°C compared to those from the 18°C/28°C group. Collectively, our results reinforce that low temperature exerts negative effects on female fertility and egg development in R. microplus, although it has no influence on A. marginale transmission to the progeny. In the field, the detrimental effects of temperatures on tick reproductive fitness lead to a reduction of tick population, which may cause a decrease in the incidence of bovine anaplasmosis.


Assuntos
Anaplasma marginale/fisiologia , Anaplasmose/transmissão , Doenças dos Bovinos/transmissão , Temperatura Baixa , Rhipicephalus/microbiologia , Anaplasmose/microbiologia , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Feminino , Larva , Masculino , Oviposição/fisiologia , Reprodução/fisiologia , Glândulas Salivares/microbiologia , Zigoto/microbiologia
7.
Osteoarthritis Cartilage ; 22(2): 344-54, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24361793

RESUMO

OBJECTIVE: To test whether the interaction between annulus fibrosus cells (AFCs) and endothelial cells (ECs) disrupts matrix homeostasis and stimulates production of innervation mediators. METHODS: Human microvascular ECs were cultured in the conditioned media of AF cell culture derived from degenerated human surgical specimen. Matrix-metalloproteinases (MMPs) and platelet-derived growth factor (PDGF) of ECs of this culture were analyzed by qRT-PCR, Western, and immunofluorescence. Vascular endothelial growth factor (VEGF), Interleukin-8 (IL-8), and nerve growth factor (NGF) in the media of this cell culture were assayed by ELISA. To determine the effects of ECs on AFCs, qRT-PCR was performed to determine mRNA levels of collagen I, II and aggrecan in AFCs cultured in EC conditioned media. RESULTS: Compared to ECs cultured in naïve media, ECs exposed to AFC conditioned media expressed higher mRNA and protein levels of key biomarkers of invasive EC phenotype, MMP-2 (2×), MMP-13 (4×), and PDGF-B (1.5-2×), and NGF (24.9 ± 15.2 pg/mL vs 0 in naïve media). Treatment of AF cells with EC culture conditioned media decreased collagen type II expression two fold. Considerable quantities of pro-angiogenic factors IL-8 (396.7 ± 302.0 pg/mL) and VEGF (756.2 ± 375.9 pg/mL) were also detected in the conditioned media of untreated AF cell culture. DISCUSSION: AFCs from degenerated discs secreted factors which stimulated EC production of factors known to induce matrix degradation, angiogenesis, and innervation. IL-8 and VEGF maybe the secreted factors from AFCs which mediate a pro-angiogenic stimulus often implicated in the development of disc degeneration.


Assuntos
Meios de Cultivo Condicionados/farmacologia , Endotélio Vascular/metabolismo , Matriz Extracelular/patologia , Degeneração do Disco Intervertebral/metabolismo , Disco Intervertebral/inervação , Adulto , Capilares/metabolismo , Sobrevivência Celular , Células Cultivadas , Colágeno Tipo II/metabolismo , Células Endoteliais/efeitos dos fármacos , Feminino , Humanos , Interleucina-8/biossíntese , Disco Intervertebral/irrigação sanguínea , Degeneração do Disco Intervertebral/patologia , Masculino , Metaloproteases/metabolismo , Pessoa de Meia-Idade , Neovascularização Patológica/metabolismo , Fator de Crescimento Neural/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Fator A de Crescimento do Endotélio Vascular/biossíntese
8.
J Agric Food Chem ; 57(20): 9378-84, 2009 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-19780535

RESUMO

A two-column solid phase extraction was used to determine the operationally defined speciation of Cu in lager beers and red wines. Applying a nonionic macroreticular adsorbing resin Amberlite XAD-16 and a gel type strong cation exchange resin Dowex 50Wx8-200, three different groupings of the chemical forms of Cu, including the hydrophobic, the cationic, and the residual species fractions, were separated and determined. The total content of Cu in the analyzed samples and its concentrations in the distinguished fractions were measured using flame atomic absorption spectrometry without any special preparation of the sample solutions. It was found that the residual species (72-82% of the total content), being polar and noncationic forms of Cu, are the most abundant fraction of Cu in the analyzed beers. In the case of wines, the fraction of the hydrophobic species was established to have the highest share in the total Cu content, that is, 27-77%. This fraction was presumed to contain relatively strong complexes of Cu with various flavonoids and other polyphenols.


Assuntos
Cerveja/análise , Cobre/química , Vinho/análise , Adsorção , Cromatografia por Troca Iônica , Cobre/isolamento & purificação , Extração em Fase Sólida , Espectrofotometria Atômica
9.
Chirurg ; 80(2): 122-9, 2009 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-19096808

RESUMO

The molecular genetic changes from certain endocrine tumors are already understood, reflecting as they do the etiology of these sporadic familial disorders. This already has clinical consequences to the treatment of familial endocrine tumors, which often appear in the course of syndromatic disorders. These consequences consist in slight changes to surgical technique, the search for other active and usually endocrinal tumors, and examination of family members for other gene carriers (of disease-specific mutations) and the most suitable prophylactic tumor therapy. In contrast, for sporadic endocrine tumors there exists far less clinically relevant knowledge. Starting with anamnesis and clinical findings of active endocrine tumors, we discuss the current possibilities for molecular genetic determination of disease-specific mutations (germline and tumor DNA) and their effect on surgical procedure.


Assuntos
Neoplasias das Glândulas Endócrinas/genética , Neoplasias das Glândulas Endócrinas/cirurgia , Análise Mutacional de DNA , DNA de Neoplasias/genética , Neoplasias das Glândulas Endócrinas/diagnóstico , Triagem de Portadores Genéticos , Testes Genéticos , Mutação em Linhagem Germinativa , Humanos , Cuidados Paliativos , Prognóstico , Síndrome
10.
Exp Clin Endocrinol Diabetes ; 116(8): 501-6, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18523916

RESUMO

INTRODUCTION: Cystic lesions of the parathyroid glands are uncommon, and rare are those that cause primary hyperparathyroidism. Preoperative diagnosis can be challenging and some of these tumors might be misinterpreted as parathyroid carcinoma. With an expertise of more than 1700 patients operated on primary hyperparathyroidism, we present six cases with cystic degeneration of a parathyroid gland causing primary hyperparathyroidism in five patients. CASE REPORTS: A woman at the age of 67 presented with hypercalcaemic crisis due to persistent primary hyperparathyroidism after an operation four years ago. As cervical exploration was unsuccessful, sternotomy was performed and a cystic adenoma of a parathyroid gland could be resected from the anterior mediastinum. The second patient - a 63-year-old female with severe hypercalcaemic crisis, operated on under suspicion of a parathyroid carcinoma - had a functional cyst of the parathyroid gland with a parathyroid hormone level of 700,000 pg/ml in the aspirated fluid. Third, operation on a 70-year-old woman with a benign euthyreot goiter and the laboratory findings of primary hyperparathyroidism revealed a cystic adenoma adjacent to the thyroid gland, whose aspirate had a parathyroid hormone level of 1,500,000 pg/ml. In the fourth case of a 67-year-old female with an adenoma of the right inferior parathyroid gland localized by ultrasonography, the cystic parathyroid adenoma was operated on by video-assistance. A cystic structure in the upper mediastinum was diagnosed in the fifth patient, a 66-year-old woman. It was suspected to be a thyroid cyst at the left-lower pole of the thyroid gland. After hemithyroidectomy pathological evaluation revealed a large parathyroid cyst. The last case of a 56-year-old male illustrates the extensive preoperative work-up of a patient with primary hyperparathyroidism who was preoperatively diagnosed as having a thyroid cyst. Final histopathological examination exposed multiple gland disease with a parathyroid adenoma as well as a cystic parathyroid gland. DISCUSSION: Cystic adenomas of the parathyroid glands are often misdiagnosed as thyroid cysts or - in the case of extremely elevated parathyroid hormone levels - even as parathyroid carcinoma. The routine preoperative diagnostic tools, such as ultrasonography or (99m)Tc-sestamibi-scintigraphy, cannot clearly distinguish between these entities and might be jeopardized by mediastinal localization, which is not uncommon in parathyroid adenomas with cystic degeneration.


Assuntos
Cistos/patologia , Cistos/cirurgia , Hiperparatireoidismo/cirurgia , Doenças das Paratireoides/patologia , Doenças das Paratireoides/cirurgia , Idoso , Feminino , Humanos , Hiperparatireoidismo/etiologia , Hiperparatireoidismo/patologia , Masculino , Pessoa de Meia-Idade
11.
Chirurg ; 79(6): 571-5, 2008 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-17879074

RESUMO

Benign adrenal gland tumors smaller than 6 cm are nowadays the indication for minimally invasive surgery. Until now there has been no significant difference between retroperitoneoscopic and transabdominal adrenalectomy. Intestinal adhesions could be a contraindication against transabdominal laparoscopic adrenalectomy, and therefore the retroperitoneoscopic approach could be an advantage in these cases. A prospective study concerning this question has not been published yet. Our clinical investigation here includes 114 adrenalectomies during the last 5 years. We show that in any case of abdominal preoperation, laparoscopic adrenalectomy can be performed by transabdominal approach and without conversion to open surgery. Discussed are the different indications for laparoscopic adrenalectomy, operating time, conversion rate to open surgery, and amount and type of abdominal preoperation. We compared patients with and without abdominal preoperations.


Assuntos
Abdome/cirurgia , Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia , Adenoma Adrenocortical/cirurgia , Carcinoma/cirurgia , Síndrome de Cushing/cirurgia , Laparoscopia , Feocromocitoma/cirurgia , Adolescente , Adrenalectomia/métodos , Adulto , Idoso , Contraindicações , Feminino , Humanos , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Complicações Pós-Operatórias/etiologia , Reoperação , Aderências Teciduais/complicações , Aderências Teciduais/cirurgia
12.
Talanta ; 71(1): 411-8, 2007 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19071320

RESUMO

A simple and versatile protocol, based on use of solid phase extraction on strong ion exchangers and off-line detection by flame atomic absorption spectrometry, was devised to fractionate iron and zinc in common dietary food and beverages products, i.e., bee honeys, fruit juices and tea infusions. In the procedure proposed, cation exchanger Dowex 50Wx4 and anion exchanger Dowex 1x4 were used separately for distinguishing broadly meant the cationic metal fraction and the fraction of stable anionic metal complexes, respectively, after retention of metal species and their exhaustive elution by means of a 4.0moll(-1) HCl solution. The third fraction, referred to the residual metal species, was retrieved by difference between total soluble metal contents and sum of metal quantities in separated cationic and anionic fractions. The fractionation pattern observed for both metals was described and discussed.

13.
Clin Rehabil ; 20(3): 246-53, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16634344

RESUMO

OBJECTIVE: To determine if adults in the subacute phase post moderate or mild stroke could learn a motor task under implicit practice conditions. DESIGN: Non-randomized, between-group design. SETTING: Subjects' homes. SUBJECTS: Sample of convenience of 15 adults with moderate stroke, 22 adults with mild stroke, and 32 age-matched controls. Stroke severity was determined using the Orpington Prognostic Scale. INTERVENTION: Practice of movements to target switches in two conditions, a repeated series and a random series. Practice was organized into a single session of six blocks of 80 trials such that blocks 1 and 2 were the random series, blocks 3 and 4 the repeated series, block 5 the random series, and block 6 the repeated series. Explicit knowledge of the two conditions was not provided. MAIN MEASURES: The mean response time and the coefficient of variation were calculated for each block for each group. RESULTS: Regardless of group, participants had a slower response time when practice was unexpectedly switched from the repeated to random condition. The response time and coefficient of variation for those with moderate stroke were persistently greater than those with mild stroke and controls, who were not different from each other. CONCLUSIONS: Implicit motor learning is preserved in adults with moderate stroke and may be a viable strategy for teaching motor skills in rehabilitation. The clinician should be aware that subjects with moderate stroke, even when performing with the less affected upper extremity, have significantly slower and more variable movements than those with mild stroke and controls.


Assuntos
Aprendizagem , Destreza Motora , Modalidades de Fisioterapia , Reabilitação do Acidente Vascular Cerebral , Idoso , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Prática Psicológica , Tempo de Reação , Aprendizagem Seriada
14.
Talanta ; 69(5): 1227-33, 2006 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18970707

RESUMO

An analytical procedure was proposed to study the operational fractionation of Ca and Mg in bee honeys, fruit juices and tea infusions. The protocol devised was based on the solid phase extraction of distinct metal fractions on different sorbents, namely strong acidic cation exchanger Dowex 50W x 4, weak acidic cation exchanger Diaion WT01S and strong basic anion exchange resin Dowex 1 x 4. For the evaluation of the amounts of the metal fractions distinguished, a flame atomic absorption spectrometry was used off-line prior to the determination of Ca and Mg concentrations in the effluents obtained. It was established that Ca and Mg are mostly present in the analysed samples in the form of cationic species (96-100%). The accuracy of the entire fractionation scheme and sample preparation procedures involved was verified by the performance of the recovery tests.

15.
Talanta ; 67(1): 155-61, 2005 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18970149

RESUMO

Metalfix Chelamine chelating resins of two different bead sizes (150-300 and 40-80mum) were examined and compared regarding their application for sorption of Au, Ir, Pd, Pt, Rh and Ru ions from medium of HCl, HNO(3) and mixtures of HCl and HNO(3). The quantitative enrichment of Au, Ir, Pd and Pt was established for the resin of 150-300mum particle size and for solutions acidified with HCl and HNO(3) (3:1) up to the concentration of 0.50moll(-1). In the case of Rh and Ru, the uptake of these metals by the resin was lower than 50%. For the elution, solutions of different reagents, i.e. HCl, HNO(3), KCN, KI, KSCN and (NH(2))(2)CS, were studied with respect to the complete release of the analytes retained by the resin. In addition, influence of various base metals, i.e. Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, on the retention of the noble metals was investigated. Under the selected conditions for the retention and elution of Au, Ir, Pd and Pt, the analytical performance of the proposed pre-concentration procedure was evaluated and it was applied to the determination of these noble metals in anodic sludge sample.

16.
Phys Ther ; 81(11): 1780-9, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11694171

RESUMO

BACKGROUND AND PURPOSE: A motor skill can be learned implicitly, without awareness of what is being learned. The purpose of this study was to examine the ability of adults who had unilateral stroke to learn implicitly a perceptual-motor task. SUBJECTS: Subjects were 47 people who were poststroke and 36 control subjects. METHODS: Participants performed sequences of hand movements in response to target lights in 2 conditions: a patterned sequence and a random sequence. Participants were not given explicit knowledge of the presence of the 2 conditions. Those who had stroke performed with the upper-extremity ipsilateral to the lesion. RESULTS: Subjects who had stroke performed more slowly than control subjects. For both groups, times decreased with practice of the patterned sequence, increased with introduction of the random sequence, and decreased again with reintroduction of the patterned sequence. Group differences persisted in a retention test given the next day of the patterned sequence, and both groups showed decreased times over the course of the retention test. DISCUSSION AND CONCLUSION: People with stroke are able to learn a perceptual-motor task even without explicit instructions regarding the patterned sequence embedded in the task.


Assuntos
Aprendizagem , Desempenho Psicomotor , Acidente Vascular Cerebral/psicologia , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Memória , Pessoa de Meia-Idade , Prática Psicológica , Tempo de Reação , Acidente Vascular Cerebral/fisiopatologia
17.
J Gen Physiol ; 118(4): 333-40, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11585847

RESUMO

To understand how plasma membranes may limit water flux, we have modeled the apical membrane of MDCK type 1 cells. Previous experiments demonstrated that liposomes designed to mimic the inner and outer leaflet of this membrane exhibited 18-fold lower water permeation for outer leaflet lipids than inner leaflet lipids (Hill, W.G., and M.L. Zeidel. 2000. J. Biol. Chem. 275:30176-30185), confirming that the outer leaflet is the primary barrier to permeation. If leaflets in a bilayer resist permeation independently, the following equation estimates single leaflet permeabilities: 1/P(AB) = 1/P(A) + 1/P(B) (Eq. l), where P(AB) is the permeability of a bilayer composed of leaflets A and B, P(A) is the permeability of leaflet A, and P(B) is the permeability of leaflet B. Using for the MDCK leaflet-specific liposomes gives an estimated value for the osmotic water permeability (P(f)) of 4.6 x 10(-4) cm/s (at 25 degrees C) that correlated well with experimentally measured values in intact cells. We have now constructed both symmetric and asymmetric planar lipid bilayers that model the MDCK apical membrane. Water permeability across these bilayers was monitored in the immediate membrane vicinity using a Na+-sensitive scanning microelectrode and an osmotic gradient induced by addition of urea. The near-membrane concentration distribution of solute was used to calculate the velocity of water flow (Pohl, P., S.M. Saparov, and Y.N. Antonenko. 1997. Biophys. J. 72:1711-1718). At 36 degrees C, P(f) was 3.44 +/- 0.35 x 10(-3) cm/s for symmetrical inner leaflet membranes and 3.40 +/- 0.34 x 10(-4) cm/s for symmetrical exofacial membranes. From, the estimated permeability of an asymmetric membrane is 6.2 x 10(-4) cm/s. Water permeability measured for the asymmetric planar bilayer was 6.7 +/- 0.7 x 10(-4) cm/s, which is within 10% of the calculated value. Direct experimental measurement of P(f) for an asymmetric planar membrane confirms that leaflets in a bilayer offer independent and additive resistances to water permeation and validates the use of.


Assuntos
Bicamadas Lipídicas/química , Água/química , Animais , Bovinos , Cães , Lipossomos/química , Modelos Biológicos , Concentração Osmolar , Permeabilidade
18.
Int J Cardiovasc Imaging ; 17(4): 315-25, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11599871

RESUMO

INTRODUCTION: Late potentials (LP) are markers of arrhythmogenic events after myocardial infarction (MI). The localization of LP sources would help to identify arrhythmogenic myocardium. The purpose of this study was to localize these LP sources from non-invasive body surface mapping data. METHODS AND RESULTS: Six patients were investigated with cardiac MRI and signal averaged 62-lead magnetocardiography after MI. Three of them were suffering from sustained ventricular tachycardia (VT). Sophisticated computer algorithms were used in order to compute the current density on the surface of the left ventricle. We compared these current density distributions for the entire QRS complex and the high frequency LP signals. In the three patients which had premature ventricular complexes (PVCs) we localized the exit sites of these arrhythmias. We found a close matching of the low current density areas based on the QRS complexes and the high current density areas based on the LP signals. These areas predominantly corresponded to sites of the infarctions. Exit sites of PVCs were located close to these areas. CONCLUSIONS: By means of sophisticated computer algorithms we were able to localize LP sources. This would be useful in steering catheter ablation and coronary revascularization therapies. However, the method has to be proven with the help of invasive mapping in a larger number of patients.


Assuntos
Infarto do Miocárdio/complicações , Infarto do Miocárdio/fisiopatologia , Adulto , Idoso , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Mapeamento Potencial de Superfície Corporal , Técnicas Eletrofisiológicas Cardíacas , Potenciais Evocados , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Aumento da Imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico
19.
Int J Cardiovasc Imaging ; 17(2): 153-60, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11558974

RESUMO

BACKGROUND: The site of atrioventricular pre-excitation can roughly be estimated with the help of schemes basing on a few number of electrocardiogram (ECG) leads. Computer algorithms have been developed which utilize the body surface mapping of the pre-excitation signal for the localization purpose. We tested several new algorithms. METHOD: A patient suffering from Wolff-Parkinson-White syndrome was investigated prior the catheter ablation. The body surface mapping was performed with a 62-lead magnetocardiograph. The site of pre-excitation was calculated by using different methods: the dipole method with fixed and moving dipoles, the dipole scan on the endocardium, and different current density methods (L1 norm method, L2 norm method, low resolution electromagnetic tomography (LORETA) method, and maximum entropy method). Three-dimensional (3D) magnetic resonance imagings (MRIs) of the heart were used to visualize the results. The source positions were compared to the site of catheter ablation. RESULTS: The accessory pathway was successfully ablated left laterally. This site was correctly identified by the conventional dipole method. By scanning the entire endocardial surface of the heart with the dipole method we found a circumscribed source area. This area too, was located at the lateral segment of the atrio-ventricular grove. The current density methods performed differently. Whereas the L1 norm identified the site of pre-excitation, the L2 norm, the LORETA method and the maximum entropy method resulted in extended source areas and therefore were not suited for the localization purpose. CONCLUSION: The dipole scan and the L1 norm current density method seem to be useful additions in the computational localization of pre-excitation syndromes. In our single case study they confirmed the localization results obtained with the dipole method, and they estimated the size of the suspected source region.


Assuntos
Síndrome de Wolff-Parkinson-White/diagnóstico por imagem , Adulto , Algoritmos , Ablação por Cateter/métodos , Eletrocardiografia/métodos , Humanos , Masculino , Tomografia Computadorizada de Emissão/métodos , Síndrome de Wolff-Parkinson-White/cirurgia
20.
Analyst ; 126(7): 1055-62, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11478635

RESUMO

Multidimensional (size-exclusion-anion-exchange-cation-exchange) liquid chromatography with ICP-MS detection was developed to produce a map of water-soluble species in an oyster test reference material. The presence of arsenobetaine, trimethyl(2-carboxyethyl)arsonium inner salt, arsenocholine, dimethylarsonic acid, tetramethylammonium ion, As(v) and two arsenosugars was demonstrated by ES-MS-MS. A previously unreported compound was isolated and identified by ES-MS-MS as 5-dimethylarsinoyl-beta-ribofuranose. Anion-exchange chromatography was optimized to produce a chromatographically pure peak of arsenobetaine (accounting for ca. 64% of all water-soluble As present) that was used to quantify this compound.


Assuntos
Arsênio/química , Ostreidae/química , Frutos do Mar/análise , Animais , Arsênio/análise , Arsenicais/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Espectrometria de Massas por Ionização por Electrospray
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