RESUMO
Parkinson's disease (PD) is associated with both motor and non-motor symptoms, including constipation, sensory neuropathy, depression, dementia and sleep disorder. Somatostatin (SST) is considered to be a modulator of GABAergic inhibitory transmission, and its levels are reduced in cerebrospinal fluid of PD patients. In the present study, we evaluated the changes in the expression of SST in GABAergic neurons derived from induced pluripotent stem cells (iPSCs) of PD patients. Neural cells were co-treated with the Wnt antagonist IWP-2 and Shh during neurosphere formation to induce GABA-positive forebrain interneurons. Quantitative analyses showed no significant differences, but slight decreases, in the potency of differentiation into GABAergic neurons derived from iPSCs between healthy control and patients with PARK2 mutations, who have been classified as a type of early-onset familial PD due to mutations in the parkin gene. Under this condition, the mRNA level of SST in GABAergic interneurons derived from iPSCs of PARK2-specific PD patients significantly decreased as neural maturation progressed. We also found that SST-positive GABAergic neurons were clearly reduced in GABAergic neurons derived from iPSCs of patients with PARK2 mutations. These findings suggest that the reduction in the expression level of SST in GABAergic interneurons of PD may, at least partly, lead to complex PD-induced symptoms.
Assuntos
Neurônios GABAérgicos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Interneurônios/metabolismo , Mutação/genética , Somatostatina/metabolismo , Ubiquitina-Proteína Ligases/genética , Diferenciação Celular , Linhagem Celular , Feminino , Neurônios GABAérgicos/patologia , Humanos , Interneurônios/patologia , MasculinoRESUMO
To clarify the functional changes after hospitalization due to pneumonia in elderly Japanese patients, we investigated the changes in physical functioning, nutritional routes, and diet that occurred after hospitalization in patients with nursing and healthcare-associated pneumonia (NHCAP). We analyzed 405 patients with NHCAP and compared findings with 448 patients with community-acquired pneumonia (CAP). Among the NHCAP patients, 140 (34%) patients showed a decline in activities of daily living function between baseline and discharge. After hospital discharge, 149 (37%) NHCAP patients did not return to the same residence location compared with where they were living prior to hospital admission. The frequency of this outcome was significantly higher in NHCAP patients than in CAP patients (p < 0.0001). After 6 months' follow-up, of the patients who transferred to different hospitals, 41 (73%) patients with CAP had returned to their own home, but only 16 (20%) patients with NHCAP could return home (p < 0.0001). Rates of alteration of nutritional route and type of diet from oral nutrition were significantly higher in NHCAP patients compared with CAP patients (22% vs 4%, p < 0.0001). Our results demonstrated that approximately one-third of hospitalized patients with NHCAP showed a decline in physical function. In addition, approximately one-fifth of NHCAP patients had changed their route of nutrition and type of diet. Our results indicated that physicians should attach greater importance to preventative measures against NHCAP rather than relying on antibiotic therapy post-infection in the management of pneumonia in elderly patients in order to extend their healthy life expectancy.
Assuntos
Infecções Comunitárias Adquiridas/fisiopatologia , Infecção Hospitalar/fisiopatologia , Admissão do Paciente , Pneumonia/fisiopatologia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Casas de SaúdeRESUMO
BACKGROUND: Atrioventricular block (AVB) sometimes complicates QT prolongation and torsades de pointes (TdP). METHODS AND RESULTS: The clinical and genetic background of 14 AVB patients (57±21 years, 13 females) who developed QT prolongation and TdP was analyzed. Electrophysiological characteristics of mutations were analyzed using heterologous expression in Chinese hamster ovary cells, together with computer simulation models. Every patient received a pacemaker or implantable cardioverter defibrillator; 3 patients had recurrence of TdP during follow-up because of pacing failure. Among the ECG parameters, QTc interval was prolonged to 561±76ms in the presence of AVB, but shortened to 495±42ms in the absence of AVB. Genetic screening for KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 revealed four heterozygous missense mutations of KCNQ1 or KCNH2 in 4 patients (28.6%). Functional analyses showed that all mutations had loss of functions and various gating dysfunctions of I(Ks) or I(Kr). Finally, action potential simulation based on the Luo-Rudy model demonstrated that most mutant channels induced bradycardia-related early afterdepolarizations. CONCLUSIONS: Incidental AVB, as a trigger of TdP, can manifest as clinical phenotypes of long QT syndrome (LQTS), and that some patients with AVB-induced TdP share a genetic background with those with congenital LQTS.
Assuntos
Bloqueio Atrioventricular/genética , Bloqueio Atrioventricular/fisiopatologia , Síndrome do QT Longo/genética , Síndrome do QT Longo/fisiopatologia , Mutação de Sentido Incorreto , Torsades de Pointes/genética , Torsades de Pointes/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bloqueio Atrioventricular/complicações , Bloqueio Atrioventricular/metabolismo , Células CHO , Estudos de Coortes , Simulação por Computador , Cricetinae , Cricetulus , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/genética , Canais de Potássio Éter-A-Go-Go/metabolismo , Feminino , Humanos , Ativação do Canal Iônico/genética , Canal de Potássio KCNQ1/genética , Canal de Potássio KCNQ1/metabolismo , Síndrome do QT Longo/metabolismo , Masculino , Pessoa de Meia-Idade , Torsades de Pointes/etiologia , Torsades de Pointes/metabolismoRESUMO
BACKGROUND: Drugs with I(Kr)-blocking action cause secondary long-QT syndrome. Several cases have been associated with mutations of genes coding cardiac ion channels, but their frequency among patients affected by drug-induced long-QT syndrome (dLQTS) and the resultant molecular effects remain unknown. METHODS AND RESULTS: Genetic testing was carried out for long-QT syndrome-related genes in 20 subjects with dLQTS and 176 subjects with congenital long-QT syndrome (cLQTS); electrophysiological characteristics of dLQTS-associated mutations were analyzed using a heterologous expression system with Chinese hamster ovary cells together with a computer simulation model. The positive mutation rate in dLQTS was similar to cLQTS (dLQTS versus cLQTS, 8 of 20 [40%] versus 91 of 176 [52%] subjects, P=0.32). The incidence of mutations was higher in patients with torsades de pointes induced by nonantiarrhythmic drugs than by antiarrhythmic drugs (antiarrhythmic versus others, 3 of 14 [21%] versus 5 of 6 [83%] subjects, P<0.05). When reconstituted in Chinese hamster ovary cells, KCNQ1 and KCNH2 mutant channels showed complex gating defects without dominant negative effects or a relatively mild decreased current density. Drug sensitivity for mutant channels was similar to that of the wild-type channel. With the Luo-Rudy simulation model of action potentials, action potential durations of most mutant channels were between those of wild-type and cLQTS. CONCLUSIONS: dLQTS had a similar positive mutation rate compared with cLQTS, whereas the functional changes of these mutations identified in dLQTS were mild. When I(Kr)-blocking agents produce excessive QT prolongation (dLQTS), the underlying genetic background of the dLQTS subject should also be taken into consideration, as would be the case with cLQTS; dLQTS can be regarded as a latent form of long-QT syndrome.
Assuntos
Análise Mutacional de DNA , Canais de Potássio Éter-A-Go-Go/genética , Canal de Potássio KCNQ1/genética , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/genética , Proteínas Musculares/genética , Canais de Sódio/genética , Adulto , Idoso , Animais , Simulação por Computador , Cricetinae , Canal de Potássio ERG1 , Feminino , Genótipo , Humanos , Incidência , Japão/epidemiologia , Síndrome do QT Longo/epidemiologia , Síndrome do QT Longo/fisiopatologia , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Canal de Sódio Disparado por Voltagem NAV1.5 , Fatores de Risco , TransfecçãoRESUMO
In a 34-year-old man showing short QT interval (QTc 329 ms), we identified a novel C-terminal KCNH2 mutation, R1135H. Using a heterologous expression system with CHO cells, the mutant channels were found to display a significantly slow deactivation, which resulted in a gain-of-function for reconstituted 'I(Kr)' channels. This mutation could modify clinical phenotypes for this patient.
Assuntos
Arritmias Cardíacas/genética , Síndrome de Brugada/genética , Canais de Potássio Éter-A-Go-Go/genética , Mutação/genética , Adulto , Animais , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/fisiopatologia , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/fisiopatologia , Células CHO , Cricetinae , Cricetulus , Canal de Potássio ERG1 , Humanos , Masculino , LinhagemRESUMO
QT prolongation, a risk factor for arrhythmias, can result from genetic variants in one (or more) of the genes governing cardiac repolarization as well as intake of drugs known to affect a cardiac K(+) channel encoded by human ether-a-go-go-related gene (HERG). In this paper, we will report a case of drug-induced long QT syndrome associated with an H(1)-receptor antagonist, hydroxyzine, in which a mutation was identified in the HERG gene. After taking 75 mg of hydroxyzine for several days, a 34-year-old female began to experience repetitive syncope. The deleterious effect of hydroxyzine was suspected because QTc interval shortened from 630 to 464 ms after cessation of the drug. Later on, the patient was found to harbor an A614V-HERG mutation. By using the patch-clamp technique in the heterologous expression system, we examined the functional outcome of the A614V mutation and confirmed a dominant-negative effect on HERG expression. Hydroxyzine concentration-dependently inhibited both wild-type (WT) and WT/A614V-HERG K(+) currents. Half-maximum block concentrations of WT and WT/A614V-HERG K(+) currents were 0.62 and 0.52 microM, respectively. Thus, accidental combination of genetic mutation and intake of hydroxyzine appeared to have led to a severe phenotype, probably, syncope due to torsade de pointes.
Assuntos
Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Antagonistas dos Receptores Histamínicos H1/efeitos adversos , Hidroxizina/efeitos adversos , Síncope/induzido quimicamente , Adulto , Relação Dose-Resposta a Droga , Canais de Potássio Éter-A-Go-Go/genética , Feminino , Regulação da Expressão Gênica , Antagonistas dos Receptores Histamínicos H1/administração & dosagem , Humanos , Hidroxizina/administração & dosagem , Síndrome do QT Longo/induzido quimicamente , Mutação , Técnicas de Patch-Clamp , Fenótipo , Torsades de Pointes/induzido quimicamenteRESUMO
OBJECTIVES: This study describes a novel heterozygous gain-of-function mutation in the cardiac sodium (Na+) channel gene, SCN5A, identified in a Japanese family with lone atrial fibrillation (AF). BACKGROUND: SCN5A mutations have been associated with a variety of inherited arrhythmias, but the gain-of-function type modulation in SCN5A is associated with only 1 phenotype, long-QT syndrome type 3 (LQTS3). METHODS: We studied a Japanese family with autosomal dominant hereditary AF, multiple members of which showed an onset of AF or frequent premature atrial contractions at a young age. RESULTS: The 31-year-old proband received radiofrequency catheter ablation, during which time numerous ectopic firings and increased excitability throughout the right atrium were documented. Mutational analysis identified a novel missense mutation, M1875T, in SCN5A. Further investigations revealed the familial aggregation of this mutation in all of the affected individuals. Functional assays of the M1875T Na(+) channels using a whole-cell patch-clamp demonstrated a distinct gain-of-function type modulation; a pronounced depolarized shift (+16.4 mV) in V(1/2) of the voltage dependence of steady-state inactivation; and no persistent Na+ current, which is a defining mechanism of LQTS3. These biophysical features of the mutant channels are potentially associated with increased atrial excitability and normal QT interval in all of the affected individuals. CONCLUSIONS: We identified a novel SCN5A mutation associated with familial AF. The mutant channels displayed a gain-of-function type modulation of cardiac Na+ channels, which is a novel mechanism predisposing to increased atrial excitability and familial AF. This is a new phenotype resulting from the SCN5A gain-of-function mutations and is distinct from LQTS3.
Assuntos
Fibrilação Atrial/genética , Predisposição Genética para Doença , Proteínas Musculares/genética , Mutação de Sentido Incorreto , Canais de Sódio/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Análise Mutacional de DNA , Eletrocardiografia , Feminino , Testes Genéticos , Humanos , Japão , Síndrome do QT Longo/genética , Síndrome do QT Longo/fisiopatologia , Masculino , Pessoa de Meia-Idade , Canal de Sódio Disparado por Voltagem NAV1.5 , Linhagem , Medição de Risco , Sensibilidade e Especificidade , Índice de Gravidade de DoençaRESUMO
BACKGROUND: In the LQT2 form of long QT syndrome (LQTS), mutation sites are reported to correlate with clinical phenotypes in Caucasians, but the relationship in Asian patients remains unknown. The present study was designed to determine whether the location of KCNH2 mutations would influence the arrhythmic risk in LQT2 patients. METHODS AND RESULTS: In 118 genetically-confirmed LQT2 patients (69 families, 62 KCNH2 mutations), the ECG parameters, Schwartz scores, and the incidence of cardiac events, defined as syncope, aborted cardiac arrest, and sudden cardiac death, were evaluated. To examine the effect of mutation sites, the participants were divided accordingly: pore (n=56) and non-pore (n=62) groups. The corrected QTend interval was significantly greater in the pore than in the non-pore group (QTc; 522+/-63 ms vs 490+/-49 ms, p=0.002). In this study, the clinical course of each of the probands did not differ according to the mutation sites, whereas non-probands carrying the pore site mutation experienced their first cardiac events at significantly younger age than those with the non-pore site mutation (log-rank, p=0.0005). CONCLUSIONS: In a Japanese LQT2 cohort, family members with the pore site mutation were at higher arrhythmic risk than those with the non-pore site mutation.
Assuntos
Povo Asiático/genética , Povo Asiático/estatística & dados numéricos , Síndrome do QT Longo/etnologia , Síndrome do QT Longo/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Códon sem Sentido , Estudos de Coortes , Intervalo Livre de Doença , Saúde da Família , Feminino , Deleção de Genes , Variação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Fatores de Risco , Torsades de Pointes/etnologia , Torsades de Pointes/genéticaRESUMO
INTRODUCTION: Patients with long QT syndrome (LQTS) become symptomatic in adolescence, but some become at age of >or=20 years. Since it remains unknown whether clinical features of symptomatic LQTS patients differ depending on the age of onset, we aimed to examine whether triggers for cardiac events are different depending on the age in genotyped and symptomatic LQTS patients. METHODS AND RESULTS: We identified 145 symptomatic LQTS patients, divided them into three groups according to the age of first onset of symptoms (young <20, intermediate 20-39, and older >or=40 years), and analyzed triggers of cardiac events (ventricular tachycardia, syncope, or cardiac arrest). The triggers were divided into three categories: (1) adrenergically mediated triggers: exercise, emotional stress, loud noise, and arousal; (2) vagally mediated triggers: rest/sleep; and (3) secondary triggers: drugs, hypokalemia, and atrioventricular (AV) block. In the young group, 78% of the cardiac events were initiated by adrenergically mediated triggers and 22% were vagally mediated, but none by secondary triggers. In contrast, the adrenergically mediated triggers were significantly lower in the intermediate group. The percentage of secondary triggers was significantly larger in the older group than in the other two groups (0% in young vs 23% in intermediate vs 72% in older; P < 0.0001). Concerning the subdivision of secondary triggers on the basis of genotype, hypokalemia was only observed in LQT1, drugs mainly in LQT2, and AV block only in LQT2. CONCLUSION: Arrhythmic triggers in LQTS differ depending on the age of the patients, stressing the importance of age-related therapy for genotyped LQTS patients.
Assuntos
Síndrome do QT Longo/epidemiologia , Síndrome do QT Longo/genética , Medição de Risco/métodos , Adolescente , Adulto , Distribuição por Idade , Criança , Feminino , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Genótipo , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
BACKGROUND: Accelerated intermediate inactivation, which is caused by mutations in the cardiac voltage-gated sodium channel alpha-subunit gene (SCN5A), is one of the molecular mechanisms underlying Brugada syndrome. The N406S mutation associated with Brugada syndrome results in the accelerated intermediate inactivation, in addition to unique pharmacological characteristics. METHODS: Functional sodium channels were expressed transiently in HEK293 cells by transfecting equally the alpha- and beta-subunit plasmids (1 microg/ml) and the sodium current were measured in whole-cell mode of patch-clamp recording. RESULTS: Since the N406S mutant channel has a greatly reduced use-dependent block of lidocaine, we took the advantage of the mutant channel to examine the effect of lidocaine on intermediate inactivation using wild-type (WT) and N406S mutant channels recombinantly expressed in HEK293 cells. Lidocaine (100 microM) slowed the recovery from the fast inactivation similarly for WT and N406S. On the other hand, whereas lidocaine slowed the recovery from the intermediate inactivation for WT, lidocaine accelerated the recovery for N406S. Activity-dependent loss of channel availability by repetitive 500-ms pulses was more strongly enhanced and accelerated by lidocaine for WT, but lidocaine exerted little effect on the N406S channel. CONCLUSION: We demonstrate that lidocaine may suppress Brugada syndrome associated with the N406S mutation by preventing the sodium channel from accumulating in the intermediate inactivation state.
Assuntos
Antiarrítmicos/farmacologia , Síndrome de Brugada/genética , Lidocaína/farmacologia , Proteínas Musculares/genética , Mutação de Sentido Incorreto , Canais de Sódio/efeitos dos fármacos , Síndrome de Brugada/tratamento farmacológico , Simulação por Computador , Predisposição Genética para Doença , Humanos , Masculino , Cadeias de Markov , Canal de Sódio Disparado por Voltagem NAV1.5 , Técnicas de Patch-Clamp , Canais de Sódio/genéticaRESUMO
Double-chambered right ventricle (DCRV) is a rare form of congenital heart disease in which the right ventricle is divided into a high-pressure inlet site and a low-pressure outlet site by anomalous muscle bands. We describe a patient with DCRV presenting with ventricular tachycardia.
Assuntos
Desfibriladores Implantáveis , Cardioversão Elétrica , Comunicação Interventricular/terapia , Taquicardia Ventricular/etiologia , Eletrocardiografia , Feminino , Comunicação Interventricular/complicações , Comunicação Interventricular/diagnóstico , Comunicação Interventricular/fisiopatologia , Ventrículos do Coração/anormalidades , Humanos , Pessoa de Meia-Idade , Taquicardia Ventricular/patologia , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/terapia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Função Ventricular DireitaRESUMO
The nutritional value of meat meal (MM), chicken meal (CM), and corn gluten meal (CGM) as dietary sources of protein in dry food formulated for adult cats was evaluated. Twelve healthy adult cats (11 males and 1 female) were used. Dry diets containing MM, CM, or CGM as the main protein source were given for a 3-week period in a 3 x 3 Latin-square design. Digestion and balance experiments were conducted during the last 7 d of each period. In addition, freshly voided urine was taken to determine urinary pH and number of struvite crystals. As compared with the CM diet, dry-matter digestibility was higher and lower for the MM and CGM groups, respectively. Percentages of nitrogen (N) absorption and N retention to N intake were higher in the MM group, and N utilization was not different between the CM group and the CGM group. All cats excreted alkaline urine (pH > 7). Urinary pH, struvite activity product, and number of struvite crystals in urine were lower for the CGM group. There was no difference in retention of calcium and magnesium among the groups. From the point of view of digestibility and N utilization, MM is superior to CGM, and CM is better than or equivalent to CGM as a protein source of dry foods for adult cats. However, when CM is used as a dietary protein source, some manipulation of dietary base excess may be needed to control urinary acid-base balance, because CM contains higher calcium and phosphorus.
Assuntos
Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Gatos/fisiologia , Proteínas Alimentares/administração & dosagem , Digestão , Nitrogênio/metabolismo , Animais , Cálcio/metabolismo , Cálcio/urina , Gatos/urina , Galinhas , Estudos Cross-Over , Feminino , Glutens , Concentração de Íons de Hidrogênio , Magnésio/metabolismo , Magnésio/urina , Compostos de Magnésio/urina , Masculino , Produtos da Carne , Valor Nutritivo , Fosfatos/urina , Estruvita , Urinálise/veterinária , Zea maysRESUMO
BACKGROUND AND AIM: Loss of basement membrane (BM) components, such as type IV collagen, has been demonstrated in colorectal cancer, but the fine diversity of the assembly of alpha (IV) chains, the composition of type IV collagen, and alterations in the collagen have not been fully analyzed. Here, we defined immunohistochemically the expression of alpha1-6 (IV) chains in colorectal cancer tissues and adjacent normal mucosa by the use of chain-specific monoclonal antibodies. METHODS: Tissue samples of tumor and adjacent normal mucosa obtained from patients with colorectal adenocarcinoma were stained with chain-specific monoclonal antibodies raised against synthetic peptides of individual alpha (IV) chains using an indirect immunofluorescence method. RESULTS: In the normal mucosa, alpha1 (IV), alpha2 (IV), alpha5 (IV), and alpha6 (IV) were found in the BM-delineating mucosal epithelium and the gland crypts, whereas alpha3 (IV) and alpha4 (IV) were limited to the BM of the luminal surface epithelium. In contrast, staining of alpha3-6 (IV) was rarely observed in the BM of cancer cells. Staining of alpha1 (IV) and alpha2 (IV) was reduced or lost from the cancer BM in relation to the degree of tumor differentiation: continuous staining in well-differentiated portions, discontinuous staining in moderately differentiated portions, and absence of staining in poorly differentiated portions. CONCLUSIONS: Our findings indicate that type IV collagen expression is altered in the BM of colorectal cancer as a result of changes of alpha (IV) chain expression, particularly alpha1 (IV) and alpha2 (IV), in relation to the degree of tumor differentiation.