Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 566
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Neuropediatrics ; 2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37164315

RESUMO

Acute occlusion of the anterior spinal artery and subsequent spinal ischemic infarction leads to anterior spinal artery syndrome characterized by back pain and bilateral flaccid paresis with loss of protopathic sensibility. As a rare cause fibrocartilaginous embolism has been described and is associated with sports or unusual strain.Following gymnastic exercise the day before symptom-onset, a 11 years old girl presented with neck pain, paresis of arms and legs, and impaired deep tendon reflexes. She was unable to lift her arms, grasp, stand, walk and had urinary incontinence. Magnetic resonance imaging revealed a longitudinal T2 hyperintense signal in the anterior spinal cord from C3 to C6 with accompanying bilateral diffusion restriction involving gray matter bilaterally at the level of C4 and C5 and unilaterally at the level of C3/4. The adjacent annulus fibrosus of the intervertebral disc showed a fissure without disc protrusion. Treatment with prednisolone and enoxaparin was started within 12 hours of symptom-onset and continued over 6 days and 8 weeks, respectively. After 2 months, her motor function gradually improved, spinal imaging showed persistent T2 signal hyperintense defects at the level of C4/5. After 5 months, there was only slight impairment affecting elevation and abduction of the right arm.Following physical exercise, the patient suffered from acute anterior spinal cord ischemia with imaging findings in line with a presumed fibrocartilaginous embolism. Unlike most cases, our patient showed almost complete recovery following treatment with prednisolone and enoxaparin. We speculate that the positive outcome is related to rapid treatment initiation.

2.
Z Gastroenterol ; 53(6): 591-602, 2015 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-26016456

RESUMO

Vedolizumab, the first drug in the class of anti-integrin molecules, is newly approved for ulcerative colitis and Crohn's disease and can be prescribed in Germany since mid-2014. By a specific receptor binding a relatively gut-selective mode of action was achieved without the known side effects of the systemic immunosuppression of the anti-TNF-alpha antibodies. According to the present data the safety profile of Vedolizumab appears to be more favorable than that of the anti-TNF- alpha therapy. Vedolizumab is suitable for induction therapy in patients with ulcerative colitis and Crohn's disease, however the kinetic of response compared with the anti-TNF-alpha antibodies seems to be slower. For maintenance therapy the Vedolizumab data show a deep and sustained remission in patients initially responding to induction therapy with a lower loss of efficacy in the long-term treatment known from the anti-TNF-alpha therapy. On the basis of currently available data the efficacy of Vedolizumab in ulcerative colitis appears to be slightly better than in Crohn's disease.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Anticorpos Monoclonais Humanizados/efeitos adversos , Colite Ulcerativa/diagnóstico , Doença de Crohn/diagnóstico , Medicina Baseada em Evidências , Fármacos Gastrointestinais/efeitos adversos , Fármacos Gastrointestinais/uso terapêutico , Humanos , Resultado do Tratamento
3.
Nat Genet ; 38(6): 716-20, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16732289

RESUMO

In the fungal phylum Ascomycota, the ability to cause disease in plants and animals has been gained and lost repeatedly during phylogenesis. In monocotyledonous barley, loss-of-function mlo alleles result in effective immunity against the Ascomycete Blumeria graminis f. sp. hordei, the causal agent of powdery mildew disease. However, mlo-based disease resistance has been considered a barley-specific phenomenon to date. Here, we demonstrate a conserved requirement for MLO proteins in powdery mildew pathogenesis in the dicotyledonous plant species Arabidopsis thaliana. Epistasis analysis showed that mlo resistance in A. thaliana does not involve the signaling molecules ethylene, jasmonic acid or salicylic acid, but requires a syntaxin, glycosyl hydrolase and ABC transporter. These findings imply that a common host cell entry mechanism of powdery mildew fungi evolved once and at least 200 million years ago, suggesting that within the Erysiphales (powdery mildews) the ability to cause disease has been a stable trait throughout phylogenesis.


Assuntos
Ascomicetos/patogenicidade , Proteínas de Plantas/fisiologia , Arabidopsis/genética , Arabidopsis/fisiologia , Ascomicetos/classificação , Ascomicetos/fisiologia , Filogenia , Plantas Geneticamente Modificadas , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa
4.
Z Gerontol Geriatr ; 47(4): 279-84, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25088385

RESUMO

INTRODUCTION: Growing evidence shows a high correlation between extensive use of central nervous system-acting drugs (CNSADs) in elderly patients and adverse drug reactions (ADRs) such as falls, fractures, and mortality. RESEARCH QUESTION: Are results of cognitive testing with the Mini Mental Status Examination (MMSE) influenced by use of CNSADs? SETTING: Geriatric inpatient service for acute, subacute, and rehabilitation care. METHODS: Secondary combined analysis of two prospective, single-center study cohorts (PROPSYC, 2011 and AGE OUT, 2012) with identical procedure for the MMSE at a tertiary hospital. RESULTS: Overall, 395 patients were included, 144 male (M) and 251 female (F). Mean age was 80.0 ± 8.4 years (M 76.7 ± 9.1, F 81.9 ± 7.3, p = 0.0000). Mean MMSE points were 22.9 ± 4.8 (M 23.2 ± 4.6, F 22.6 ± 5.0, p = 0.211). In total, 258 patients (65.3 %) used drugs with potential adverse cognitive properties. Analgesics with central activity were given to 117 of 395 patients (29.6 %). Low-potency opioids (tramadol hydrochloride, tilidine) were identified in 60 patients and high-potency opioids in 57 patients. Antidepressants were used in 66 patients, benzodiazepines in 26, and hypnotics in 11, while 38 patients received other CNSADs. We only found significant correlations with the results of cognitive testing for sedatives (diazepam and oxazepam, Pearson's r - 0.79, p = 0.05), but not for lorazepam. CONCLUSION: Our analysis shows an influence of sedatives (diazepam and oxazepam, but not lorazepam) on cognitive testing with the MMSE in users of CNSADs.


Assuntos
Fármacos do Sistema Nervoso Central/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Hospitalização , Entrevista Psiquiátrica Padronizada , Idoso , Idoso de 80 Anos ou mais , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/uso terapêutico , Antidepressivos/efeitos adversos , Antidepressivos/uso terapêutico , Benzodiazepinas/efeitos adversos , Benzodiazepinas/uso terapêutico , Fármacos do Sistema Nervoso Central/uso terapêutico , Transtornos Cognitivos/diagnóstico , Diazepam/efeitos adversos , Diazepam/uso terapêutico , Feminino , Humanos , Hipnóticos e Sedativos/efeitos adversos , Hipnóticos e Sedativos/uso terapêutico , Lorazepam/efeitos adversos , Lorazepam/uso terapêutico , Masculino , Oxazepam/efeitos adversos , Oxazepam/uso terapêutico
5.
J Dairy Sci ; 96(6): 3895-906, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23548282

RESUMO

The use of oral rehydration solutions (ORS) is well established as an effective treatment to correct water-, electrolyte-, and acid-base balance in diarrheic calves. The main ingredients of a commercial ORS are Na, glucose, and alkalinizing agents, such as NaHCO3. Particular importance is attributed to the combination of glucose and Na at a specific ratio to optimize intestinal sodium, and thereby water uptake, through the sodium-glucose co-transport. Enhancing intestinal Na absorption by combining glucose and Na in an ORS has the potential to improve the alkalinizing effect of an ORS according the strong ion theory. The objective of this study was to investigate the effect of glucose on the alkalinizing effect of NaHCO3 when administered orally. Nine healthy neonatal Holstein-Friesian calves underwent 3 oral treatments with 2-L solutions of NaHCO3 (150 mmol/L), glucose (300 mmol/L), and glucose + NaHCO3 (300 mmol/L + 150 mmol/L, respectively) in randomized order. Arterial and venous blood was obtained before treatment and in 30-min intervals thereafter for blood gas analysis and determination of plasma protein and electrolyte concentrations. Urine was collected volumetrically to determine urine volume, osmolality, pH, net acid excretion, and renal Na excretion after treatment. Plasma volume changes were extrapolated from plasma protein concentration changes. Treatment and time effects were tested with repeated measures ANOVA. Only subtle differences between oral administration of NaHCO3, with and without glucose, were observed for the change of the standard HCO3 concentration relative to baseline. No differences in plasma Na, plasma volume expansion, renal Na, net base excretion, urine volume, or pH could be identified between animals treated orally with NaHCO3 with and without glucose. Similarly, no differences in blood glucose concentration, plasma volume expansion, urine volume, or renal glucose excretion were observed in the 8h after treatment when comparing oral glucose treatment with and without NaHCO3. Our results indicate that combination of NaHCO3 with glucose in a hypertonic ORS only had a minor effect on the alkalinizing effect of NaHCO3, which is unlikely to be of clinical relevance. The combination of NaHCO3 and glucose neither improved Na, glucose, nor water absorption in euhydrated neonatal dairy calves, questioning the relevance of a specific ratio between Na and glucose in ORS for calves.


Assuntos
Animais Recém-Nascidos/fisiologia , Bovinos , Glucose/administração & dosagem , Bicarbonato de Sódio/administração & dosagem , Equilíbrio Ácido-Base/efeitos dos fármacos , Animais , Glicemia/análise , Proteínas Sanguíneas/análise , Cloretos/sangue , Desidratação/terapia , Desidratação/veterinária , Interações Medicamentosas , Feminino , Concentração de Íons de Hidrogênio , Volume Plasmático , Potássio/sangue , Soluções para Reidratação , Sódio/sangue
6.
Artigo em Alemão | MEDLINE | ID: mdl-23978982

RESUMO

Physical activities are particularly health effective when they are structured and systematically organized, for example, with respect to a dose-response relationship or to psychosocial aspects. Which insights can be gained from scientific knowledge on the structure of physical activities? Which health-related goals can be sought with different physical activities in the field of sport? Which target groups can be reached with these kinds of sport? These questions are addressed in this article on the basis of current scientific knowledge-to promote the development of health-enhancing physical activities especially in sport federations, but also to create a communication platform between the sport and the health sector. The work of researchers in this field is focused mainly on health-enhancing physical activity, but they are also engaged in health-related scientific organizations and in sport federations.


Assuntos
Medicina Baseada em Evidências , Promoção da Saúde/métodos , Atividade Motora/fisiologia , Aptidão Física/fisiologia , Medicina Preventiva/métodos , Reabilitação/métodos , Humanos
7.
Pol J Vet Sci ; 16(2): 403-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23971214

RESUMO

The purpose of this study was to analyze the acute effect of whole body vibration exercise (WBVE) on clinical parameters and blood values in horses. Seven horses were exposed to a 10 min WBVE at a frequency of 15-21 Hz. Clinical parameters and venous blood samples were taken before and directly after WBVE. Acute short-term WBVE produced a decrease in serum cortisol (p = 0.02) and creatine-kinase (p = 0.02) values. Clinical parameters, hematology, fibrinogen, lactate, IGF-I, GGT, creatinine, myeloperoxidase activity and bone marker values were not significantly changed by WBVE. In adult sound horses WBVE was well tolerated and did not cause any sign of measured discomfort.


Assuntos
Cavalos/fisiologia , Condicionamento Físico Animal/métodos , Vibração , Animais , Feminino , Cavalos/sangue , Masculino
8.
Neuropediatrics ; 43(5): 240-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22936351

RESUMO

BACKGROUND: Acute cerebellitis (AC) is characterized by cerebellar symptoms and magnetic resonance imaging (MRI) changes primarily confined to the cerebellum. OBJECTIVE: To analyze the neurological and cognitive long-term outcome of children with AC. METHODS: Children with AC diagnosed by typical clinical features and MRI findings were included in this retrospective study. Medical charts were reviewed and neurological deficits were assessed by neurological examination or by the expanded disability status scale telephone interview. Cognitive outcome was evaluated with a parental questionnaire (Kognitive Probleme bei Kindern und Jugendlichen). RESULTS: A total of 11 children (6 boys, 5 girls; age range: 3 years to 14 years and 10 months) were included. Of them, six children had a severe disease manifestation including mental status changes and neurological symptoms. Of the rest, two children had a moderate and three children had a mild form of AC. MRI of the cerebellum was obtained in the acute phase revealing signal alterations with different patterns. The average follow-up period was 4 years and 4 months. A complete recovery was observed in five children. Neurological sequelae were reported in five children ranging from ataxia to mild tremor. Cognitive deficits were found in six patients. The affected areas of cognition did include spatial visualization ability, language skills, and concentration. CONCLUSION: Neurological and cognitive sequelae are common in children with AC and underline the role of the cerebellum in cognition.


Assuntos
Cerebelo/patologia , Encefalite/patologia , Adolescente , Antibacterianos/uso terapêutico , Criança , Pré-Escolar , Transtornos Cognitivos/etiologia , Encefalite/complicações , Encefalite/tratamento farmacológico , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Exame Neurológico , Testes Neuropsicológicos , Valor Preditivo dos Testes , Estatística como Assunto , Resultado do Tratamento
9.
Phys Chem Chem Phys ; 14(31): 10919-34, 2012 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-22777130

RESUMO

The adsorption properties of structurally well defined bimetallic Pt/Ru(0001) surfaces, consisting of a Ru(0001) substrate partly or fully covered by monolayer Pt islands or a monolayer Pt film, were studied by temperature programmed desorption (TPD) using CO and deuterium as probe molecules. Additionally, the adsorption of CO was investigated by infrared reflection absorption spectroscopy (IRAS). The presence of the pseudomorphic platinum islands or monolayer film leads to considerable modifications of the adsorption properties for both adsorbates, both on the Pt covered and, to a smaller extent, on the bare Ru part of the surfaces. In addition to distinct weakly bound adspecies, which are adsorbed on the monolayer Pt islands, we find unique contributions from island edge desorption, from spill-over processes during the desorption run, and a general down-shift of the peak related to desorption from Pt-free Ru(0001) areas with increasing Pt coverage. These effects, which we consider as characteristic for adsorption on bimetallic surfaces with large contiguous areas of the respective types, are discussed in detail.

10.
Br J Anaesth ; 107(5): 679-86, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21890663

RESUMO

BACKGROUND: Vascular endothelium is covered by a glycocalyx. Damage to the glycocalyx after systemic inflammation or ischaemia/reperfusion contributes to increased vascular permeability and leucocyte adhesion. The underlying mechanisms leading to ischaemia/reperfusion-induced glycocalyx shedding are incompletely understood, in terms of lack of oxygen, absence of flow, or return of oxygen. METHODS: Isolated guinea pig hearts perfused with Krebs-Henseleit buffer at 37°C underwent 20 min of either stopped-flow ischaemia or hypoxic perfusion with subsequent reperfusion/reoxygenation (n = 6 each). Hearts perfused with normoxic buffer served as time controls. Epicardial transudate was collected to assess coronary net fluid filtration, colloid extravasation, and histamine release by mast cells. Syndecan-1 and heparan sulphate were measured in coronary effluent, together with lactate, purines, and the release of mast-cell tryptase ß. Additional hearts were perfusion-fixed to visualize the glycocalyx. RESULTS: Both ischaemia and hypoxia with reperfusion/reoxygenation resulted in significant increases in net fluid filtration (P < 0.05) and release of syndecan-1 and heparan sulphate in coronary effluent. These effects were already seen with the onset of hypoxic perfusion. Histamine was released during hypoxia and reoxygenation and also reperfusion, as was tryptase ß, and high concentrations of adenosine (>1 µmol litre⁻¹, hypoxia group) and inosine (> 7 µmol litre⁻¹, ischaemia group) were measured in effluent (P < 0.05). Damage to the coronary glycocalyx was evident upon electron microscopy. CONCLUSIONS: Both ischaemic and hypoxic hypoxia initiate glycocalyx degradation, promoting an increase in permeability. A contributing mechanism could be purine-mediated degranulation of resident mast cells, with liberated tryptase ß acting as potential 'sheddase'.


Assuntos
Vasos Coronários/metabolismo , Endotélio Vascular/metabolismo , Glicocálix/metabolismo , Hipóxia/metabolismo , Isquemia/metabolismo , Reperfusão , Adenosina/metabolismo , Análise de Variância , Animais , Vasos Coronários/ultraestrutura , Endotélio Vascular/ultraestrutura , Glicocálix/ultraestrutura , Cobaias , Heparitina Sulfato/metabolismo , Histamina/metabolismo , Inosina/metabolismo , Ácido Láctico/metabolismo , Masculino , Microcirculação , Microscopia Eletrônica , Purinas/metabolismo , Sindecana-1/metabolismo , Triptases/metabolismo
11.
J Dairy Sci ; 94(11): 5646-55, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22032387

RESUMO

Hyperkalemia is a common complication in neonatal diarrheic dairy calves and is corrected by administration of glucose or sodium bicarbonate. Although the hypokalemic effect of glucose is well established in other species, controversial results are reported for sodium bicarbonate. Our objective was to study the effect and mechanism of action of glucose and sodium bicarbonate on the potassium homeostasis of healthy neonatal dairy calves. Nine healthy neonatal Holstein-Friesian calves underwent 3 oral treatments with 2L of NaHCO(3) (150 mmol/L), glucose (300 mmol/L), and glucose+NaHCO(3) solution (300 mmol/L+150 mmol/L) in randomized order. Blood was obtained before treatment (T(0)) and at 30-min intervals thereafter. Changes between each time point and T(0) were determined for all parameters. Urine was collected volumetrically to determine total renal potassium excretion over an 8-h posttreatment period. Plasma volume changes were extrapolated from changes in plasma protein concentration. Treatment and time effects were tested with repeated-measures ANOVA. Multivariate stepwise regression analysis using dummy variable coding was conducted to identify associations between changes in plasma potassium concentration ([K]) and changes in plasma glucose concentration ([glucose]), blood base excess, and plasma volume. Oral glucose and sodium bicarbonate treatments decreased [K] by 25 and 19%, respectively, whereas the combination of both compounds caused an intermediate [K] decline (22%). For the glucose treatment, the decline in [K] was only associated with changes in plasma [glucose] (partial R(2)=0.19). In NaHCO(3)-treated calves, [K] decline was associated with change of extracellular volume (partial R(2)=0.31) and blood base excess (partial R(2)=0.19). When glucose and NaHCO(3) were combined, [K] decline was associated with changes in plasma volume (partial R(2)=0.30), BE (R(2)=0.22), and [glucose] (partial R(2)=0.03). Our results indicate that glucose lowers plasma [K] mainly through an insulin-dependent intracellular translocation of K, whereas NaHCO(3) causes hypokalemia through hemodilution followed by intracellular translocation of K caused by the strong ion effect. The combination of glucose and NaHCO(3) at the dosage used in this study does not have an additive hypokalemic effect. When combined, hemodilution and strong ion effect have the strongest effect on plasma [K], whereas the insulin-dependent effect of glucose appears to be blunted.


Assuntos
Glucose/farmacologia , Rim/efeitos dos fármacos , Potássio/sangue , Bicarbonato de Sódio/farmacologia , Animais , Animais Recém-Nascidos , Transporte Biológico/efeitos dos fármacos , Glicemia/análise , Bovinos , Indústria de Laticínios , Glucose/administração & dosagem , Masculino , Volume Plasmático/efeitos dos fármacos , Volume Plasmático/veterinária , Potássio/metabolismo , Distribuição Aleatória , Bicarbonato de Sódio/administração & dosagem , Fatores de Tempo
12.
FASEB J ; 23(7): 2065-75, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19237503

RESUMO

Senile graying of human hair has been the subject of intense research since ancient times. Reactive oxygen species have been implicated in hair follicle melanocyte apoptosis and DNA damage. Here we show for the first time by FT-Raman spectroscopy in vivo that human gray/white scalp hair shafts accumulate hydrogen peroxide (H(2)O(2)) in millimolar concentrations. Moreover, we demonstrate almost absent catalase and methionine sulfoxide reductase A and B protein expression via immunofluorescence and Western blot in association with a functional loss of methionine sulfoxide (Met-S=O) repair in the entire gray hair follicle. Accordingly, Met-S=O formation of Met residues, including Met 374 in the active site of tyrosinase, the key enzyme in melanogenesis, limits enzyme functionality, as evidenced by FT-Raman spectroscopy, computer simulation, and enzyme kinetics, which leads to gradual loss of hair color. Notably, under in vitro conditions, Met oxidation can be prevented by L-methionine. In summary, our data feed the long-voiced, but insufficiently proven, concept of H(2)O(2)-induced oxidative damage in the entire human hair follicle, inclusive of the hair shaft, as a key element in senile hair graying, which does not exclusively affect follicle melanocytes. This new insight could open new strategies for intervention and reversal of the hair graying process.


Assuntos
Envelhecimento , Cor de Cabelo , Peróxido de Hidrogênio/metabolismo , Metionina/análogos & derivados , Estresse Oxidativo , Catalase/análise , Folículo Piloso/patologia , Humanos , Metionina/análise , Metionina/deficiência , Espécies Reativas de Oxigênio/metabolismo , Regeneração
13.
Neuropediatrics ; 41(6): 261-3, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21445816

RESUMO

We report on an otherwise healthy infant who presented with clusters of alternating central facial nerve paresis. At 11 months of age, the patient showed intermittent facial asymmetry compatible with right-sided upper motor neuron facial paresis and accompanying incomplete upper motor neuron hypoglossal paresis. Laboratory work-up and imaging studies did not reveal signs of infection, infarction or structural lesions, and after one week, symptoms spontaneously resolved. Similar episodes affecting alternate sides were noted at ages of 17, 27 and 49 months lasting for 4-14 days. At 49 months, EEG showed right temporo-occipital benign sharp waves with activation during drowsiness and sleep. A diagnosis of benign focal epilepsy with negative motor phenomena was made. She is now 60 months old and no further episodes have occurred without antiepileptic treatment. Ictal orofacial phenomena are the clinical hallmark of benign focal epilepsy with centro-temporal sharp waves (BECTS). As in our patient, negative epileptic motor phenomena frequently lead to a broad diagnostic work-up. In infants presenting with episodic central facial nerve paresis, the possibility of negative epileptic motor phenomena should be considered.


Assuntos
Epilepsia/complicações , Doenças do Nervo Facial/diagnóstico , Paralisia Facial/diagnóstico , Eletroencefalografia , Doenças do Nervo Facial/complicações , Doenças do Nervo Facial/fisiopatologia , Paralisia Facial/complicações , Paralisia Facial/fisiopatologia , Feminino , Humanos , Lactente
14.
Science ; 168(3929): 385-6, 1970 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-5435898

RESUMO

Addition of antimycin A to a culture of Tetrahymena pyriformis caused an increase in cell division and protein synthesis in this ciliated protozoan. The antimycin effect is a function of the time of exposure to the antibiotic as well as of the age of the culture. A large accumulation of endoplasmic reticulum, reflecting increased protein synthesis, was visualized by electron microscopy in cells stimulated by the antimycin A.


Assuntos
Antimicina A/farmacologia , Divisão Celular/efeitos dos fármacos , Biossíntese de Proteínas , Tetrahymena/citologia , Tetrahymena/metabolismo , Retículo Endoplasmático , Microscopia Eletrônica , Estimulação Química , Tetrahymena/efeitos dos fármacos
15.
Science ; 251(4996): 942-4, 1991 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-2000495

RESUMO

The structure of the ion conduction pathway or pore of voltage-gated ion channels is unknown, although the linker between the membrane spanning segments S5 and S6 has been suggested to form part of the pore in potassium channels. To test whether this region controls potassium channel conduction, a 21-amino acid segment of the S5-S6 linker was transplanted from the voltage-activated potassium channel NGK2 to another potassium channel DRK1, which has very different pore properties. In the resulting chimeric channel, the single channel conductance and blockade by external and internal tetraethylammonium (TEA) ion were characteristic of the donor NGK2 channel. Thus, this 21-amino acid segment controls the essential biophysical properties of the pore and may form the conduction pathway of these potassium channels.


Assuntos
Canais de Potássio/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/fisiologia , Quimera , Clonagem Molecular , Feminino , Ativação do Canal Iônico , Potenciais da Membrana , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Oócitos/fisiologia , Reação em Cadeia da Polimerase , Canais de Potássio/efeitos dos fármacos , Canais de Potássio/genética , Ratos , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico , Tetraetilamônio , Compostos de Tetraetilamônio/farmacologia , Xenopus
16.
J Inherit Metab Dis ; 32 Suppl 1: S321-5, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19894140

RESUMO

Hurler-Scheie syndrome is caused by alpha-l-iduronidase deficiency. Enzyme replacement therapy (ERT) can improve physical capacity and reduces organomegaly. However, the effect on bradytrophic connective tissue is limited. As intravenously administered enzyme cannot cross the blood-brain barrier, the therapy of choice for the more severe Hurler syndrome is haematopoietic stem cell transplantation (HCT). In the more attenuated Scheie syndrome, neurological impairment is less severe; therefore, ERT may be appropriate to treat these patients. Information on long-term outcome in Scheie patients undergoing ERT is scarce. We report a 38-year-old female Scheie patient who has been on ERT for 8 years. While non-neurological symptoms improved, she developed paresthesias in her hands and feet and progressive pain in her legs. Somatosensory evoked potentials were abnormal, suggesting dysfunction of the dorsal funiculus and lemniscus medialis. After 6 years of ERT, a spinal MRI showed dural thickening at the upper cervical spine. These soft-tissue deposits are presumably due to the accumulation of mucopolysaccharides. Intramedullary hyperintensities at the level of C1/2 revealed cervical myelopathy. An MRI before the start of ERT had shown milder spinal lesions. Cystic lesions in the white matter of the centrum semiovale due to dilated Virchow-Robin spaces were essentially unchanged compared with the MRI scan before ERT. Decompression of the spinal cord resulted in clinical improvement. In an adult patient with Scheie syndrome, ERT failed to prevent progression of cervical myelopathy. Clinical significance of cerebral changes is unclear. Whether early HCT or intrathecal ERT could have prevented these lesions remains speculative.


Assuntos
Terapia de Reposição de Enzimas , Iduronidase/uso terapêutico , Mucopolissacaridose I/complicações , Mucopolissacaridose I/tratamento farmacológico , Compressão da Medula Espinal/etiologia , Adulto , Encéfalo/patologia , Vértebras Cervicais , Progressão da Doença , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Mucopolissacaridose I/fisiopatologia , Compressão da Medula Espinal/patologia , Compressão da Medula Espinal/fisiopatologia
17.
Nuklearmedizin ; 48(5): 201-7, 2009.
Artigo em Alemão | MEDLINE | ID: mdl-19639164

RESUMO

AIM: Investigation of the biodistribution and calculation of dosimetry of Ga-68-DOTATOC- for patients imaged in the routine clinical setting for diagnosis or exclusion of neuroendocrine tumours. PATIENTS, METHODS: Dynamic PET/CT-imaging (Biograph 16) was performed over 20 min in 14 patients (8 men, 6 women) after injection of (112+/-22) MBq 68Ga-DOTATOC followed by whole body 3D-acquisition (8 bed positions, 3 or 4 min each) 30 min p.i. and 120 min p.i.. Urinary tracer elimination was measured and blood activity was derived non-invasively from the blood pool of the heart. The relevant organs for dosimetry were spleen, kidneys, liver, adrenals, urinary bladder and pituitary gland. Dosimetry was performed using OLINDA/EXM 1.0 software and specific organ uptake was expressed as standardized uptake values (SUVs). RESULTS: Rapid physiological uptake of the radiotracer could be demonstrated in liver, spleen and kidneys, adrenals and pituitary gland (mean SUVs were 6, 20, 16, 10, and 4, respectively). Radiotracer elimination was exclusively via urine (16% of injected dose within 2h); no redistribution could be observed. The spleen and the kidneys received the highest radiation exposure (0.24 mSv/MBq, 0.22 mSv/MBq resp.), mean effective dose yielded 0.023 mSv/MBq. CONCLUSION: 68Ga-DOTATOC is used extensively for diagnosis of somatostatin receptor positive tumours because it has several advantages over the 111In-labelled ligand. The derived dosimetric values are lower than first approximations from the biological data of OctreoScan. The use of CT for transmission correction of the PET data delivers radiation exposure up to 1 mSv (low dose).


Assuntos
Radioisótopos de Gálio , Octreotida/análogos & derivados , Adulto , Idoso , Osso e Ossos/efeitos da radiação , Exposição Ambiental , Feminino , Radioisótopos de Gálio/farmacocinética , Humanos , Rim/efeitos da radiação , Fígado/efeitos da radiação , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Octreotida/farmacocinética , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos
18.
Klin Padiatr ; 221(7): 430-5, 2009 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-20013566

RESUMO

In 1991, Biedermann coined the term "kinetic imbalance due to suboccipital strain" ("KiSS-syndrome"). He assumed a functional abnormality of the suboccipital-high cervical spine, resulting in positional preference of the infant;s head. A broad spectrum of symptoms and complaints have been attributed to "KiSS-Syndrome". Patients are advised to undergo manual therapy, with pressure applied locally in order to readjust the cervical spine. Life threatening side-effects have been published repeatedly. We present two infants with brain tumours who developed torticollis and further neurological findings such as ataxia and reflex differences. In both cases, symptoms caused by the tumour were interpreted as "KiSS-syndrome", and appropriate diagnostics and therapy were delayed for months. There is no scientific evidence for the actual existence of "KiSS-syndrome" as a clinical entity or for the positive effects of manual therapy. Approximately 12% of all infants <12 months show a positional preference of the head, about 8% present with body asymmetry. Whereas most cases are benign, there is a long list of serious differential diagnoses for torticollis in infants. We give an updated review of the literature regarding "KiSS-Syndrome" and discuss the differential diagnostics in infants with torticollis.


Assuntos
Algoritmos , Astrocitoma/diagnóstico , Neoplasias Cerebelares/diagnóstico , Vértebras Cervicais , Ganglioglioma/diagnóstico , Imageamento por Ressonância Magnética , Segunda Neoplasia Primária/diagnóstico , Doenças da Coluna Vertebral/diagnóstico , Torcicolo/etiologia , Astrocitoma/patologia , Astrocitoma/cirurgia , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/cirurgia , Pré-Escolar , Erros de Diagnóstico , Transtornos Neurológicos da Marcha/etiologia , Ganglioglioma/patologia , Ganglioglioma/cirurgia , Humanos , Lactente , Masculino , Microcirurgia , Neoplasia Residual/diagnóstico , Segunda Neoplasia Primária/patologia , Segunda Neoplasia Primária/cirurgia , Exame Neurológico , Complicações Pós-Operatórias/diagnóstico , Reoperação , Síndrome
19.
J Dairy Sci ; 92(4): 1649-59, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19307647

RESUMO

The aim of the study was to investigate the influence of oral rehydration solutions (ORS) on milk clotting, abomasal pH, electrolyte concentrations, and osmolality, as well as on the acid-base status in blood of suckling calves, as treatment with ORS is the most common therapy of diarrhea in calves to correct dehydration and metabolic acidosis. Oral rehydration solutions are suspected to inhibit abomasal clotting of milk; however, it is recommended to continue feeding cow's milk or milk replacer (MR) to diarrheic calves to prevent body weight losses. Three calves with abomasal cannulas were fed MR, MR-ORS mixtures, or water-ORS mixtures, respectively. Samples of abomasal fluid were taken before and after feeding at various time points, and pH, electrolyte concentrations, and osmolality were measured. The interference of ORS with milk clotting was examined in vivo and in vitro. To evaluate the effects of ORS on systemic acid-base status, the Stewart variables strong ion difference ([SID]), acid total ([A(tot)]), and partial pressure of CO2 (pCO2) were quantified in venous blood samples drawn before and after feeding. Calves reached higher abomasal pH values when fed with MR-ORS mixtures than when fed MR. Preprandial pH values were re-established after 4 to 6 h. Oral rehydration solutions prepared in water increased the abomasal fluid pH only for 1 to 2 h. Oral rehydration solutions with high [SID(3)] ([Na(+)] + [K(+)] - [Cl(-)]) values produced significantly higher abomasal pH values and area under the curve data of the pH time course. Caseinomacropeptide, an indicator of successful enzymatic milk clotting, could be identified in every sample of abomasal fluid after feeding MR-ORS mixtures. The MR-ORS mixtures with [SID(3)] values > or =92 mmol/L increased serum [SID(3)] but did not change venous blood pH. Oral rehydration solutions do not interfere with milk clotting in the abomasum and can, therefore, be administered with milk. In this study, MR-ORS mixtures with high [SID(3)] values caused an increase of serum [SID(3)] in healthy suckling calves and may be an effective treatment for metabolic acidosis in calves suffering from diarrhea.


Assuntos
Abomaso/efeitos dos fármacos , Equilíbrio Ácido-Base/efeitos dos fármacos , Bovinos/fisiologia , Soluções para Reidratação/farmacologia , Abomaso/química , Animais , Animais Lactentes , Análise Química do Sangue , Dióxido de Carbono/análise , Concentração de Íons de Hidrogênio , Masculino , Leite/química , Substitutos do Leite/farmacologia , Concentração Osmolar , Volume Plasmático/efeitos dos fármacos , Volume Plasmático/veterinária , Soluções para Reidratação/química , Fatores de Tempo
20.
Neuron ; 8(3): 499-505, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1550675

RESUMO

The pore of a chimeric K+ channel, CHM, differed from its parental host channel, Kv2.1, by 9 amino acids. Four were located in a putative deep region and 5 in a nearby outer mouth. Point reversions were without restorative effects, and reversions V369I or L374V in the deep pore produced novel phenotypes. Among double mutations, only V369I and L374V were effective in restoring the Kv2.1 pore phenotype. Adding a change in charge at Q382K in the outer pore fully restored the parental phenotype. Thus, the pore appears to have an inner, deep region where ions such as K+ and TEA+ may be regulated by nonpolar residues and an outer region where ions may be regulated by charged residues.


Assuntos
Canais de Potássio/fisiologia , Sequência de Aminoácidos , Animais , Condutividade Elétrica , Ativação do Canal Iônico , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Oócitos , Potássio/fisiologia , Proteínas Recombinantes , Relação Estrutura-Atividade , Compostos de Tetraetilamônio/metabolismo , Xenopus laevis
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA