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1.
Endoscopy ; 40(10): 799-805, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18828075

RESUMO

BACKGROUND AND STUDY AIMS: We have recently proposed a classification of mucosal morphology in Barrett's esophagus based on three criteria: regularity of mucosal pattern, regularity of vascular pattern, and presence of abnormal blood vessels. We aimed to evaluate the interobserver agreement with the proposed mucosal morphology classification and to assess the additional value of narrow band imaging (NBI) over high resolution white light endoscopy (HR-WLE). PATIENTS AND METHODS: Five international experts in the field of Barrett's imaging and seven community endoscopists with no expertise in this field independently evaluated magnified still images from 50 areas, obtained with HR-WLE and NBI, in Barrett's esophagus patients. Visual analogue scales (VAS) were used for scoring imaging quality. Interobserver agreement for mucosal morphology and yield for identifying early neoplasia were assessed. RESULTS: Imaging qualities of NBI were rated more highly than HR-WLE, when evaluated separately as well as in a side-by-side comparison. The interobserver agreement ranged from 0.40 to 0.56 and did not significantly differ between expert and non-expert endoscopists. The overall yield for correctly identifying images of early neoplasia was 81 % for HR-WLE, 72 % for NBI and 83 % for HR-WLE + NBI, with no significant difference between experts and non-experts. CONCLUSION: Interobserver agreement for the classification of mucosal morphology was moderate. Although NBI was rated more highly than HR-WLE for imaging quality, this did not result in improved interobserver agreement or increased yield for identifying early neoplasia in Barrett's esophagus. This applied to non-expert as well as expert endoscopists.


Assuntos
Esôfago de Barrett/patologia , Carcinoma/patologia , Endoscopia , Neoplasias Esofágicas/patologia , Mucosa/patologia , Lesões Pré-Cancerosas/patologia , Esôfago de Barrett/classificação , Competência Clínica , Humanos , Aumento da Imagem , Luz , Microscopia , Mucosa/irrigação sanguínea , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Estudos Retrospectivos
2.
FEBS Lett ; 581(29): 5586-90, 2007 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-18005662

RESUMO

Epithelial calcium (re)absorption is mediated by TRPV5 and TRPV6 channels. TRPV5 is modulated by the SGK1 kinase, a process requiring the PDZ-domain containing scaffold protein NHERF2. The present study explored whether TRPV6 is similarly regulated by SGKs and the scaffold proteins NHERF1/2. In Xenopus oocytes, SGKs activate TRPV6 by increasing its plasma membrane abundance. Deletion of the putative PDZ binding motif on TRPV6 did not abolish channel activation by SGKs. Furthermore, coexpression of neither NHERF1 nor NHERF2 affected TRPV6 or potentiated the SGKs stimulating effect. The present observations disclose a novel TRPV6 regulatory mechanism which presumably participates in calcium homeostasis.


Assuntos
Canais de Cálcio/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Canais de Cálcio/genética , Epitélio/metabolismo , Humanos , Camundongos , Oócitos/enzimologia , Oócitos/metabolismo , Domínios PDZ , Técnicas de Patch-Clamp , Fosfoproteínas/metabolismo , Isoformas de Proteínas/metabolismo , Transdução de Sinais , Trocadores de Sódio-Hidrogênio/metabolismo , Canais de Cátion TRPV/genética , Xenopus
3.
Hum Mutat ; 27(11): 1158-9, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17041897

RESUMO

Mutations in GJB2, the gene encoding for the Gap Junction protein Connexin 26 (Cx26), have been established as the major cause of hereditary, non-syndromic hearing impairment (HI). We report here the identification of a novel point mutation in GJB2, c.40A>G [p.N14D], detected in compound heterozygosity with the c.35delG mutation in two brothers with moderate non-syndromic sensorineural HI. The mother who carried one wildtype and a p.N14D allele displayed normal hearing. The mutation leads to substitution of the neutral amino acid asparagine (N) by the negatively charged aspartic acid (D) at amino acid number 14, a position that is conserved among Cx26 of different organisms and among many other connexin isoforms. To investigate the impact of this mutation on protein function, Cx26 activity was measured by depolarization activated hemichannel conductance in non-coupled Xenopus laevis oocytes. Oocytes injected with the p.N14D mutant cRNA showed strongly reduced currents compared to wildtype. Coinjection of wildtype and mutant cRNA at equimolar levels restored the conductive properties supporting the recessive character of this mutation. Total Cx26 protein expression and cell surface abundance examined by western blotting and by quantitative immunoassays revealed that the hemichannel was properly synthesized but not integrated into the plasma membrane. In this study we have shown that the GJB2 mutation p.N14D is associated with recessively inherited HI and exhibits a defective phenotype due to diminished expression at the cell surface.


Assuntos
Conexinas/genética , Perda Auditiva/genética , Mutação , Transporte Proteico/fisiologia , Animais , Antígenos de Superfície/genética , Membrana Celular/fisiologia , Criança , Pré-Escolar , Clonagem Molecular , Conexina 26 , Conexinas/metabolismo , Análise Mutacional de DNA , Junções Comunicantes/fisiologia , Expressão Gênica , Perda Auditiva/etiologia , Humanos , Técnicas In Vitro , Masculino , Oócitos/metabolismo , Linhagem , Xenopus laevis
4.
Neurobiol Dis ; 22(1): 112-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16300957

RESUMO

Mutations in GJB2, which encodes the gap junction protein connexin 26 (Cx26), are one of the major causes for inherited and sporadic nonsyndromic hearing impairment. This study aimed to functionally characterize more frequent GJB2 mutations identified in patients showing nonsyndromic hearing impairment. Following injection of wild type and mutated cRNA in Xenopus oocytes, Cx26 hemichannel activity was measured by depolarization activated conductance in noncoupled oocytes. All mutants showed a partially or completely defective phenotype, except (V27I)Cx26, a polymorphism tested as positive control. Coexpression of wild type and mutant Cx26 injected at equimolar levels revealed that p.M34T, p.V37I and p.I82M, but not p.G59V, p.L90P, p.R127H and p.R143W exert a dominant inhibitory effect. When coexpressed with Cx30, a connexin partially colocalized with Cx26 in the cochlea, all mutants had a dominant behavior. This study provides data that might be important for the improvement of genetic diagnosis and counseling for patients with hearing impairment.


Assuntos
Conexinas/genética , Junções Comunicantes/metabolismo , Predisposição Genética para Doença/genética , Perda Auditiva Neurossensorial/genética , Mutação/fisiologia , Animais , Membrana Celular/genética , Membrana Celular/metabolismo , Cóclea/metabolismo , Cóclea/fisiopatologia , Conexina 26 , Conexina 30 , Conexinas/química , Conexinas/metabolismo , Células Epiteliais/metabolismo , Retroalimentação Fisiológica/genética , Feminino , Junções Comunicantes/genética , Perda Auditiva Neurossensorial/metabolismo , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Potenciais da Membrana/genética , Oócitos , Técnicas de Patch-Clamp , Potássio/metabolismo , Estrutura Terciária de Proteína/fisiologia , Xenopus laevis
5.
Biochem Soc Trans ; 33(Pt 1): 213-5, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15667310

RESUMO

The serum- and glucocorticoid-inducible kinase SGK1 is an ubiquitously expressed kinase with the ability to regulate a variety of transport systems. Recent observations point to a role of SGK1 in the regulation of diverse physiological functions such as epithelial transport and cardiac and neuronal excitability. At least partially through its effect on transport, SGK1 contributes to a number of pathophysiological conditions including metabolic syndrome and fibrosing disease.


Assuntos
Transporte Biológico/fisiologia , Proteínas Nucleares/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Ativação Enzimática , Proteínas Imediatamente Precoces , Proteínas Nucleares/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo
6.
Am J Physiol Gastrointest Liver Physiol ; 287(1): G143-50, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15044175

RESUMO

Serum and glucocorticoid-inducible kinase 1 (SGK1) is highly expressed in enterocytes. The significance of the kinase in regulation of intestinal function has, however, remained elusive. In Xenopus laevis oocytes, SGK1 stimulates the epithelial Na(+) channel by phosphorylating the ubiquitin ligase Nedd4-2, which regulates channels by ubiquitination leading to subsequent degradation of the channel protein. Thus the present study has been performed to explore whether SGK1 regulates transport systems expressed in intestinal epithelial cells, specifically type IIb sodium-phosphate (Na(+)-P(i)) cotransporter (NaPi IIb). Immunohistochemistry in human small intestine revealed SGK1 colocalization with Nedd4-2 in villus enterocytes. For functional analysis cRNA encoding NaPi IIb, the SGK isoforms and/or the Nedd4-2 were injected into X. laevis oocytes, and transport activity was quantified as the substrate-induced current (I(P)). Exposure to 3 mM phosphate induces an I(P) in NaPi IIb-expressing oocytes. Coinjection of Nedd4-2, but not the catalytically inactive mutant (C938S)Nedd4-2, significantly downregulates I(P), whereas the coinjection of (S422D)SGK1 markedly stimulates I(P) and even fully reverses the effect of Nedd4-2 on I(P). The effect of (S422D)SGK1 on NaPi IIb is mimicked by wild-type SGK3 but not by wild-type SGK2, constitutively active (T308D,S473D)PKB, or inactive (K127N)SGK1. Moreover, (S422D)SGK1 and SGK3 phosphorylate Nedd4-2. In conclusion, SGK1 stimulates the NaPi IIb, at least in part, by phosphorylating and thereby inhibiting Nedd4-2 binding to its target. Thus the present study reveals a novel signaling pathway in the regulation of intestinal phosphate transport, which may be important for regulation of phosphate balance.


Assuntos
Proteínas de Transporte/fisiologia , Íleo/metabolismo , Proteínas Nucleares , Proteínas Serina-Treonina Quinases/fisiologia , Simportadores/metabolismo , Animais , Células Cultivadas , Enterócitos/metabolismo , Humanos , Íleo/citologia , Proteínas Imediatamente Precoces , Proteínas de Membrana , Camundongos , Técnicas de Patch-Clamp , Fosforilação , Proteínas Cotransportadoras de Sódio-Fosfato , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIb , Xenopus laevis
7.
Eur J Gastroenterol Hepatol ; 13(8): 941-4, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11507359

RESUMO

DESIGN AND METHODS: Prospectively, the effect of a lactose-restricted diet was evaluated among irritable bowel syndrome patients with lactose malabsorption. Lactose malabsorption was defined by a positive hydrogen breath test and a positive blood-glucose test. An analysis of symptoms was completed before, during, 6 weeks after and 5 years after starting the diet. In addition, the number of visits made by the patients to the outpatient clinic was scored during 6 years. RESULTS: In 17 out of 70 irritable bowel syndrome patients (24.3%), lactose malabsorption was detected. There was no difference in the symptom score between patients with a positive lactose tolerance test and patients with a negative lactose tolerance test. After 6 weeks of the lactose-restricted diet, symptoms were markedly improved in lactose malabsorption-positive patients (P < 0.001). After 5 years, one patient was lost for follow-up, and 14 out of the remaining 16 lactose malabsorption patients (87.5%) still had no complaints during the lactose-restricted diet. Two patients chose not to follow the diet continuously and accepted the discomfort caused by lactose intake. Only two out of 16 patients (12.5%) no longer experienced any benefit from lactose restriction. In the 5 years before their diagnosis of lactose malabsorption, these 16 patients visited the outpatient clinic a total of 192 times (mean 2.4 visits per year per person; range 1-7 visits). In the 5 years after diagnosis, they visited the outpatient clinic a total of 45 times (mean 0.6 visits per year per person; range 0-6 visits; P < 0.0001). CONCLUSIONS: In a large majority of irritable bowel syndrome patients with lactose malabsorption, which was previously clinically unrecognized, a lactose-restricted diet improved symptoms markedly both in the short term and the long term. Furthermore, visits by all patients to the outpatient clinic were reduced by 75%. We conclude that diet therapy is extremely cost- and time-saving. Therefore, it is strongly recommended that lactose malabsorption, which is easily treatable, is excluded before diagnosing irritable bowel syndrome.


Assuntos
Doenças Funcionais do Colo/diagnóstico , Carboidratos da Dieta/administração & dosagem , Intolerância à Lactose/dietoterapia , Teste de Tolerância a Lactose , Lactose/administração & dosagem , Adolescente , Adulto , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Erros de Diagnóstico , Feminino , Seguimentos , Humanos , Intolerância à Lactose/diagnóstico , Masculino , Pessoa de Meia-Idade
8.
Pflugers Arch ; 442(5): 688-92, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11512024

RESUMO

In the study of epithelial cell biology, primary cell cultures or cell lines grown to confluency offer considerable advantages compared with isolated cells and cell clusters. This is due mainly to the development of appropriate cell-to-cell contacts that are a prerequisite for cell polarity and thus vectorial solute transport. On the other hand, electrical coupling via gap junctions in most instances significantly hinders the use of voltage-clamp techniques for electrophysiological analysis of transport processes in single cells. In the present study we employed the gap junctional blocker 18-beta-glycyrrhetinic acid (BGA) to reduce electrical cell-to-cell coupling in confluent primary cultures of rat hepatocytes. In current-clamp experiments, 40 micromol/l BGA reversibly increased apparent cell input resistance approximately tenfold. Due to this partial electrical isolation of cells, two-channel voltage-clamp experiments became feasible and, for the first time, the hypertonicity-induced Na+ conductance of rat hepatocytes could be analysed quantitatively. In ion substitution experiments, however, it became obvious that BGA, while leaving Na+ and K+ conductances virtually unchanged, completely blocked cell membrane Cl- conductance. This additional effect of BGA necessitates independent control experiments to ensure that the transport process under consideration is itself not changed by the compound. Nevertheless, BGA may serve as a powerful tool for the quantitative electrophysiological study of epithelial cells that are in quasi physiological contact with their neighbours.


Assuntos
Junções Comunicantes/fisiologia , Ácido Glicirretínico/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/fisiologia , Técnicas de Patch-Clamp , Animais , Transporte Biológico , Células Cultivadas , Cloretos/metabolismo , Condutividade Elétrica , Ácido Glicirretínico/análogos & derivados , Ratos , Sódio/metabolismo
9.
J Intellect Disabil Res ; 45(Pt 3): 212-8, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11422645

RESUMO

Constipation is a common problem in people with intellectual disability (ID). Laxatives are frequently prescribed with disappointing results. The prevalence of constipation was investigated in a random population of 215 people with ID (IQ < 50) and constipation was correlated with clinical symptoms. All subjects were scored for bowel habits. Constipation was defined as having a bowel movement less than three times a week or the necessity of using laxatives more than three times a week. Further possible accompanying factors were evaluated. The control subjects were defined as individuals who did not use laxatives. Subjects with constipation were defined as patients and were compared to subjects without constipation (controls). One hundred and forty-nine out of 215 cases (69.3%) showed constipation. Constipation was significantly correlated with non-ambulancy, cerebral palsy, the use of anticonvulsive medication or benzodiazepines, H2-receptor antagonists or proton pump inhibitors, food refusal, and an IQ < 35. Fifty-eight per cent of the patients used bisacodyl or magnesium oxide, 39% lactulose, 13% sodiumlaurylsulphoacetate/sodium citrate/sorbitol and only 10% were given sodium phosphate enemas. Faecal soiling was found in 15% of subjects, while manual evacuation of faeces was performed in nearly 7% of cases. Constipation was randomly demonstrated in almost 70% of the population with ID. Subjects with the above-mentioned accompanying factors are especially at risk for constipation. Contrary to the general population, constipation in people with ID is associated with little use of phosphate enemas, microlax, a low incidence of faecal soiling and manual evacuation of faeces, suggesting an aetiology without distal faecal impaction. The regimen and effect of therapy has to be studied to define adequate treatment schedules.


Assuntos
Constipação Intestinal/epidemiologia , Institucionalização , Deficiência Intelectual/epidemiologia , Adolescente , Adulto , Idoso , Catárticos/uso terapêutico , Criança , Constipação Intestinal/etiologia , Constipação Intestinal/terapia , Estudos Transversais , Uso de Medicamentos , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Países Baixos
10.
FEBS Lett ; 494(1-2): 125-8, 2001 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-11297748

RESUMO

The epithelial Na(+) channel (ENaC) is composed of the subunits alpha, beta, and gamma [Canessa et al., Nature 367 (1994) 463-467] and typically exhibits a high affinity to amiloride [Canessa et al., Nature 361 (1993) 467-470]. When expressed in Xenopus oocytes, conflicting results were reported concerning the osmo-sensitivity of the channel [Ji et al., Am. J. Physiol. 275 (1998) C1182-C1190; Hawayda and Subramanyam, J. Gen. Physiol. 112 (1998) 97-111; Rossier, J. Gen. Physiol. 112 (1998) 95-96]. Rat hepatocytes were the first system in which amiloride-sensitive sodium currents in response to hypertonic stress were reported [Wehner et al., J. Gen. Physiol. 105 (1995) 507-535; Wehner et al., Physiologist 40 (1997) A-4]. Moreover, all three ENaC subunits are expressed in these cells [Böhmer et al., Cell. Physiol. Biochem. 10 (2000) 187-194]. Here, we injected specific antisense oligonucleotides directed against alpha-rENaC into single rat hepatocytes in confluent primary culture and found an inhibition of hypertonicity-induced Na(+) currents by 70%. This is the first direct evidence for a role of the ENaC in cell volume regulation.


Assuntos
Canais de Sódio/fisiologia , Animais , Membrana Celular/fisiologia , Células Cultivadas , DNA Antissenso , Eletrofisiologia , Canais Epiteliais de Sódio , Hepatócitos/citologia , Soluções Hipertônicas , Masculino , Ratos , Ratos Wistar , Canais de Sódio/genética , Xenopus laevis
11.
Int J Artif Organs ; 24(11): 793-8, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11797849

RESUMO

Aim of the study was to evaluate a hybrid liver support system in a porcine model of acute liver failure, after hepatectomy. Pigs with a body weight of 70+/-18 kg underwent total hepatectomy and porto-cavo-caval shunting as well as ligation of the bile duct and the hepatic artery. Control animals were connected to the system (including capillary membrane plasma separation) containing a four compartment bioreactor with integral oxygenation and decentralized mass exchange but without liver cells. The treatment group received hybrid liver support with the same system including 370+/-42 g primary isolated porcine parenchymal liver cells in co-culture with hepatocyte nursing cells, tissue engineered to liver- like structures at high density. Treatment started after complete recovery from anesthesia and was performed continuously. A positive influence on peripheral vascular resistance and a reduced need of catecholamine dosage was observed in the treatment group. Hybrid liver support with a cell module upscaled for clinical application significantly prolonged survival time in animals after hepatectomy with the longest survival being 26 hours in the control group an 57 hours in the treatment group.


Assuntos
Falência Hepática Aguda/terapia , Fígado Artificial , Animais , Feminino , Hepatectomia/efeitos adversos , Hepatectomia/mortalidade , Técnicas In Vitro , Falência Hepática Aguda/etiologia , Modelos Animais , Análise de Sobrevida , Suínos
12.
Cell Physiol Biochem ; 10(5-6): 335-40, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11125214

RESUMO

The initial event in the regulatory volume increase (RVI) of rat hepatocytes is an uptake of extracellular Na(+) that is then exchanged for K(+) via stimulation of Na(+)/K(+)-ATPase. While it was generally assumed that this Na(+) uptake is mediated by the activation of Na(+)/H(+) antiport and Na(+)-K(+)-2Cl(-) symport it could be shown recently that, in addition to these transporters, hypertonic stress also stimulates conductive Na(+) entry. In a quantitative study, it was found that the relative contribution of Na(+) conductance, Na(+)/H(+) antiport, and Na(+)-K(+)-2Cl(-) symport to the initial Na(+) import as well as to the RVI process (at 300 --> 400 mosmol/l) is approximately 4 : 1 : 1. When the osmotic sensitivity of these Na(+) importers was tested (at 300 mosmol/l --> 327, 360, 400, 450 mosmol/l) it became clear that Na(+) conductance is the prominent mechanism of RVI from 360 mosmol/l upwards whereas Na(+)/H(+) antiport is the most sensitive transporter with 65 % of its maximal activation at 327 mosmol/l already. Concerning the intracellular regulation of the Na(+) importers involved in RVI it was found that Na(+) concuctance as well as Na(+)-K(+)-2Cl(-) symport - but not Na(+)/H(+) antiport - are activated via PKC. With respect to the molecular correlate of the volume activated Na(+) conductance it could be shown that it exhibits a rather low affinity to amiloride (IC(50) = 6.0 micromol/l) and an overall sensitivity profile of EIPA > amiloride > benzamil = phenamil that, at first sight, would not speak in favor of a typical epithelial type of Na(+) channel (ENaC). Western-blot analysis and RT-PCR techniques, however, revealed that alpha-, beta-, as well as gamma-ENaC are, in fact, expressed in rat hepatocytes. Moreover, by use of an antisense-DNA based approach it could be shown that at least alpha-ENaC is part of the hypertonicity induced Na(+) conductance.


Assuntos
Hepatócitos/metabolismo , Sódio/metabolismo , Animais , Transporte de Íons , Concentração Osmolar , Ratos
13.
Cell Physiol Biochem ; 10(4): 187-94, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11093028

RESUMO

At moderate cell shrinkage, activation of Na(+) channels is the most prominent mechanism of regulatory cell volume increase in rat hepatocytes. The amiloride sensitivity of these channels suggests a relation to the family of epithelial Na(+) channels (ENaCs). The present study was performed to determine the pharmacological profile of shrinkage-activated Na(+) channels and to test for ENaC expression in primary cultures of rat hepatocytes; in addition, the influence of the cell volume regulated serine/threonine kinase hSGK on activity and pharmacological profile of rENaC was examined in Xenopus oocytes. Conventional electrophysiology in hepatocytes reveals that the shrinkage-activated Na(+) channel is inhibited by amiloride and EIPA with IC(50) values of 6.0 and 0.12 micromol/l, respectively. Western blots and RT-PCR demonstrate that rat hepatocytes do express all three subunits (alpha, beta, gamma) of ENaC. Coexpression of hSGK with rENaC in Xenopus oocytes reveals that the kinase stimulates ENaC by a factor of 4. Moreover, hSGK decreases the affinity to amiloride (increase of IC(50) from 0.12 to 0.26 micromol/l) and increases the affinity to EIPA (decrease of IC(50) from 250 to 50 micromol/l). In conclusion, rat hepatocytes express ENaC, which is activated by the cell volume-sensitive kinase hSGK. ENaC may contribute to the Na(+) channels activated by osmotic cell shrinkage in hepatocytes, whereby the relatively low amiloride and high EIPA sensitivity of the channel could at least be partially due to modification by SGK, which decreases the amiloride and increases the EIPA sensitivity of ENaC.


Assuntos
Hepatócitos/citologia , Hepatócitos/metabolismo , Ativação do Canal Iônico , Proteínas Nucleares , Canais de Sódio/metabolismo , Sódio/metabolismo , Amilorida/análogos & derivados , Amilorida/farmacologia , Animais , Tamanho Celular , Células Cultivadas , DNA Complementar/genética , Canais Epiteliais de Sódio , Hepatócitos/efeitos dos fármacos , Humanos , Proteínas Imediatamente Precoces , Immunoblotting , Concentração Inibidora 50 , Microinjeções , Oócitos/metabolismo , Concentração Osmolar , Pressão Osmótica , Técnicas de Patch-Clamp , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Subunidades Proteicas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Canais de Sódio/química , Canais de Sódio/genética , Xenopus
14.
Am J Gastroenterol ; 95(8): 1868-72, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10950028

RESUMO

Gastroesophageal reflux disease (GERD) is an important and frequently occurring problem among intellectually disabled individuals (IDI). Early suspicion and recognition of the presence of GERD in IDI is the cornerstone of adequate management of these patients. The prevalence of GERD among institutionalized IDI with an IQ < 50 is about 50%, with 70% of these reflux patients having endoscopically established reflux esophagitis. In case of symptoms as hematemesis, rumination, or dental erosions, there is an increased risk for GERD. GERD has also been shown to be associated with cerebral palsy, an IQ < 35, scoliosis, and the use of anticonvulsant drugs or benzodiazepines. To establish the diagnosis, 24-h pH measurement or endoscopy should be used in all those intellectually disabled individuals in whom GERD clinically is suspected. The efficacy of proton-pump inhibitors (PPIs) in IDI with GERD is indisputable. In IDI, adults as well as children, PPIs are highly effective, independent of the severity of esophagitis. Marked improvement of symptoms and quality of life can be noticed after medical treatment, thereby decreasing the need for surgery in this complicated group of patients.


Assuntos
Refluxo Gastroesofágico/fisiopatologia , Refluxo Gastroesofágico/psicologia , Pessoas com Deficiência Mental , Esôfago de Barrett/etiologia , Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/terapia , Humanos , Incidência
15.
Ned Tijdschr Geneeskd ; 144(24): 1156-61, 2000 Jun 10.
Artigo em Holandês | MEDLINE | ID: mdl-10876694

RESUMO

The prevalence of gastroesophageal reflux disease among institutionalised intellectually disabled individuals with an IQ < 50 is high: about 50% have an deviant 24-hour pH measurement and 70% of them have refluxoesophagitis. Intellectually disabled individuals have an increased risk of gastroesophageal reflux disease in case of cerebral palsy, IQ < 35, scoliosis, use of anticonvulsant drugs or benzodiazepines, not being ambulant, and in case of symptoms such as haematemesis, rumination or dental erosions. To establish the diagnosis is difficult because of the aspecific symptoms. Reflux disease is only diagnosed at a late stage. 24-hour pH measurement should be used in all those intellectually disabled individuals in whom gastroesophageal reflux disease is clinically suspected. For the treatment of gastro-oesophageal reflux disease in adults as well as children, proton pump inhibitors are highly effective, independent of the severity of oesophagitis. Marked improvement of symptoms and quality of life can be noticed after treatment.


Assuntos
Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/terapia , Gastrostomia , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Pessoas com Deficiência Mental/estatística & dados numéricos , Adulto , Distribuição por Idade , Criança , Contraindicações , Refluxo Gastroesofágico/epidemiologia , Humanos , Países Baixos/epidemiologia , Pessoas com Deficiência Mental/psicologia , Prevalência , Fatores de Risco , Índice de Gravidade de Doença
16.
J Neurochem ; 73(6): 2389-96, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10582598

RESUMO

EAAC1-mediated glutamate transport concentrates glutamate across plasma membranes of brain neurons and epithelia. In brain, EAAC1 provides a presynaptic uptake mechanism to terminate the excitatory action of released glutamate and to keep its extracellular concentration below toxic levels. Here we report the effect of well known anxiolytic compounds, benzodiazepines, on glutamate transport in EAAC1-stably transfected Chinese hamster ovary (CHO) cells and in EAAC1-expressing Xenopus laevis oocytes. Functional properties of EAAC1 agreed well with already reported characteristics of the neuronal high-affinity glutamate transporter (Km D-Asp,CHO cells: 2.23+/-0.15 microM; Km D-Asp,oocytes: 17.01+/-3.42 microM). In both expression systems, low drug concentrations (10-100 microM) activated substrate uptake (up to 200% of control), whereas concentrations in the millimolar range inhibited (up to 50%). Furthermore, the activation was more pronounced at low substrate concentrations (1 microM), and the inhibition was attenuated. The activity of other sodium cotransporters such as the sodium/D-glucose cotransporter SGLT1, stably transfected in CHO cells, was not affected by benzodiazepines. In electrophysiological studies, these drugs also failed to change the membrane potential of EAAC1-expressing Xenopus laevis oocytes. These results suggest a direct action on the glutamate transporter itself without modifying the general driving forces. Thus, in vivo low concentrations of benzodiazepines may reduce synaptic glutamate concentrations by increased uptake, providing an additional mechanism to modulate neuronal excitability.


Assuntos
Sistema X-AG de Transporte de Aminoácidos , Ansiolíticos/farmacologia , Proteínas de Transporte/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Proteínas do Tecido Nervoso/efeitos dos fármacos , Simportadores , Animais , Sítios de Ligação , Células CHO , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Clozapina/farmacologia , Cricetinae , Cricetulus , Diazepam/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Proteínas de Transporte de Glutamato da Membrana Plasmática , Transporte de Íons , Lorazepam/farmacologia , Medazepam/farmacologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Oócitos , Oxazepam/farmacologia , Proteínas Recombinantes de Fusão/efeitos dos fármacos , Proteínas Recombinantes de Fusão/metabolismo , Sódio/metabolismo , Xenopus laevis
17.
Am J Gastroenterol ; 94(3): 804-10, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10086670

RESUMO

OBJECTIVE: The prevalence of gastroesophageal reflux disease (GERD) was randomly investigated among Dutch and Belgian intellectually disabled individuals. METHODS: In six institutes including 1607 residents, 435 persons with IQ <50 underwent 24-h esophageal pH-metry and were scored for possible predisposing factors and characteristic reflux symptoms. In 49 (11.2%) cases the test failed because of technical reasons. A pathological pH test was defined as a pH <4 for >4.5% of the measured time. Subjects with a pathological pH test (patients) were compared with those with a normal pH test (controls). RESULTS: Of the remaining individuals, 51.8% (200/386) showed a normal pH test, whereas 186 showed a pathological pH test (median duration pH <4: 14.2%, range: 4.5-78.4%). As possible predisposing factors scoliosis, cerebral palsy, use of anticonvulsant drugs or other benzodiazepines, and IQ <35 were found, whereas symptoms such as vomiting, hematemesis, rumination, and depressive symptoms were indicative for reflux. At endoscopy reflux esophagitis was diagnosed in 129 of the 186 patients (69.4%). In 61 (47.3%) of 129 patients, grade I, 43 (33.3%) grade II, 25 (19.4%) grade III/IV (Savary-Miller) were found. Barrett's esophagus was found in 18 (14.0%) and peptic strictures in five (3.9%) cases. CONCLUSIONS: An abnormal 24-h pH-metry and symptoms suggestive for GERD were documented frequently in a large cohort of institutionalized intellectually disabled individuals. Further endoscopical evaluation confirmed the diagnosis of reflux esophagitis in the majority of these individuals.


Assuntos
Refluxo Gastroesofágico/complicações , Institucionalização , Deficiência Intelectual/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bélgica/epidemiologia , Criança , Esofagite Péptica/complicações , Esofagite Péptica/diagnóstico , Esofagite Péptica/epidemiologia , Esôfago/metabolismo , Feminino , Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/epidemiologia , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Prevalência , Fatores de Risco
18.
Arch Pediatr Adolesc Med ; 152(11): 1113-8, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9811290

RESUMO

OBJECTIVE: To study extensively the therapeutic approach of gastroesophageal reflux disease in intellectually disabled children. DESIGN: We studied the effect of omeprazole sodium on healing and symptom relief in 52 institutionalized intellectually disabled children (male-female, 21:31; mean age, 15.4 years; range, 4-19 years). INTERVENTION: Endoscopically proven esophagitis (grades I-IV, Savary-Miller classification) was treated with omeprazole sodium, 40 mg/d (20 mg/d for children weighing <20 kg) as healing dose for 3 months, and 20 mg/d (10 mg/d for children weighing <20 kg) as maintenance dose for another 3 months. After 3 and 6 months, results of treatment were evaluated using symptom scoring and/or endoscopy. For patients with relapse, the dose was increased. RESULTS: At first endoscopy, 19 patients (36%) of 52 showed grade I esophagitis; 20 (38%), grade II; 6 (12%), grade III; and 7 (13%), grade IV. In 44 (86%) of 51 patients, treatment was effective in healing esophagitis and keeping patients in remission, independent of the severity of esophagitis. In 7 patients (14%), a symptomatic relapse was observed after decreasing the dose. However, these patients became symptom free again after increasing the dose and showed healing on endoscopy at the end of the study. One child did not finish the study for reasons not related to therapy. Marked improvement of persistent vomiting, regurgitation, food refusal, iron deficiency anemia, and signs of depression was seen at the end. CONCLUSIONS: Omeprazole is highly effective for all grades of esophagitis in intellectually disabled children, without adverse effects. The dose needed to maintain the remission can be titrated according to the reflux symptoms. One disadvantage of medical therapy is that it is open ended, in contrast to operation, but surgery in this population has high mortality and complication rates.


Assuntos
Antiulcerosos/uso terapêutico , Esofagite Péptica/tratamento farmacológico , Refluxo Gastroesofágico/tratamento farmacológico , Omeprazol/uso terapêutico , Pessoas com Deficiência Mental , Adolescente , Adolescente Institucionalizado , Criança , Criança Institucionalizada , Pré-Escolar , Esofagite Péptica/complicações , Feminino , Refluxo Gastroesofágico/complicações , Humanos , Masculino
19.
Scand J Gastroenterol ; 33(9): 993-7, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9759958

RESUMO

BACKGROUND: A high risk of developing sludge or gallstones has been associated with pregnancy. The aim of this study was to relate the prevalence of sludge and gallstones during and shortly after pregnancy to fasting gallbladder volume as an indicator of gallbladder motility. METHODS: The population included 114 apparently healthy pregnant women from the Outpatient Clinic of Obstetrics of a large regional hospital and from the practices of regional midwives. Ultrasonography of the gallbladder was performed at weeks 15, 25, and 35 of gestation and at week 3 and month 6 postpartum. RESULTS: At gestational week 15, 3 women had gallstones and 10 had sludge (mean volume, 33.8 ml), and 99 women had a normal gallbladder (mean volume, 30.5 ml). At week 25, 1 woman with a normal gallbladder formed gallstones and underwent cholecystectomy shortly after, and 22 women had sludge, of whom 13 had a normal gallbladder at first examination (mean volume, 33.2 ml). In 88 women with normal gallbladders (of whom 2 had sludge at week 15) mean volume was 31.9 ml. At week 35, 2 women had gallstones, and 21 had sludge (mean volume, 30.5 ml). In the remaining 79 women the gallbladders were clear (mean volume, 29.5 ml). Eight women developed sludge and two women gallstones in normal gallbladders at week 25. Seven women with sludge at week 25 had a normal gallbladder at week 35. Three weeks postpartum only 10 of 100 women had sludge (mean volume, 29.1 ml). Of these 10, 9 women had a normal gallbladder at week 35. Twenty of 21 women with sludge at week 35 had normal gallbladders week 3 postpartum. Gallstones found at week 35 had disappeared. In the women with a normal gallbladder the mean volume was decreased to 19.7 ml (P < 0.0001). Six months postpartum, sludge was found in 6 (mean volume, 18.4 ml) of 93 women (mean volume, 20.3 ml), of whom 5 had a normal gallbladder at week 3 postpartum. Only 61 women showed a normal gallbladder at each examination of the study. No differences in patient characteristics were found between women with normal gallbladders and those with sludge or gallstones. CONCLUSIONS: Fasting gallbladder volume was increased in all pregnant women. This could not explain the formation of sludge or gallstones during gestation. Decrement of gallbladder volumes after delivery was faster in normal, clear gallbladders. More than a prerequisite, increased fasting gallbladder volume seemed to be a permissive factor of pregnancy-associated gallstone formation.


Assuntos
Colelitíase/etiologia , Vesícula Biliar/diagnóstico por imagem , Período Pós-Parto/fisiologia , Complicações na Gravidez/etiologia , Gravidez/fisiologia , Adulto , Jejum , Feminino , Humanos , Trimestres da Gravidez , Ultrassonografia
20.
J Am Coll Cardiol ; 30(5): 1374-83, 1997 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9350942

RESUMO

OBJECTIVES: We sought to analyze risk factors for long-term survival (up to 36 years) after surgical repair of tetralogy of Fallot (TOF). BACKGROUND: Survival after repair is excellent, but data >20 years are rare. METHODS: From 1958 to 1977, 658 patients underwent correction of TOF at our institution and were analyzed for survival. Of this patient group (age 12.2 +/- 8.6 years [mean +/- SD], range 2 to 67), 39.7% had a previous palliation. Operative (n = 139) and 1-year (n = 29) deaths were excluded for long-term calculations, resulting in a study group of 490 patients. RESULTS: Actuarial 10-, 20-, 30- and 36-year survival rates were 97%, 94%, 89% and 85%, respectively. Mortality increased 25 years postoperatively from 0.24%/year to 0.94%/year (p = 0.003). The most common cause of death was sudden death (n = 13), followed by congestive heart failure (n = 6). Multivariate correlates of impaired long-term survival were date of operation (before 1970, p = 0.0104), preoperative polycythemia (p = 0.0487) and use of a right ventricular (RV) outflow patch (p = 0.0079). Postoperative systolic RV/left ventricular pressure ratio and age showed no influence. Patients without preoperative polycythemia and an RV outflow patch (n = 164) had a 36-year actuarial survival rate of 96% and normal life expectancy. CONCLUSIONS: Cyanosis, operative experience of the surgeon and an RV outflow tract patch influence long-term outcome after repair of TOF in older children. Early repair by experienced surgeons to avoid polycythemia and excessive RV hypertrophy is supported by this study. However, mortality risk increases 25 years postoperatively, and thus heart monitoring should be intensified.


Assuntos
Tetralogia de Fallot/mortalidade , Análise Atuarial , Causas de Morte , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Análise Multivariada , Estenose da Valva Pulmonar/complicações , Reoperação , Fatores de Risco , Análise de Sobrevida , Tetralogia de Fallot/complicações , Tetralogia de Fallot/cirurgia , Fatores de Tempo , Função Ventricular Esquerda , Função Ventricular Direita
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