RESUMO
STUDY OBJECTIVES: To assess the possible brain abnormalities in adult patients with moderate and severe obstructive sleep apnea (OSA) using the mean kurtosis (MK) from diffusion kurtosis imaging (DKI) and analyze the correlation between MK and cognitive function. METHODS: A total of 30 patients with moderate and severe OSA and 30 healthy controls (HCs) evaluated by the Montreal Cognitive Assessment (MoCA) scale were enrolled. All subjects underwent DKI and 3D T1-weighted imaging (T1WI) on a 3.0T MR scanner. The MK values of gray and white matter brain regions were compared. Partial correlation analysis was used to analyze the correlation between respiratory sleep parameters/cognitive score and MK values in different brain regions. RESULTS: Compared with the HCs, the MK of 20 brain regions (13 after false discovery rate (FDR) correction) and cognitive scores in the OSA group were significantly lower. In the OSA group, the apnea-hypopnea index (AHI) was negatively correlated with the MK in the white matter of the right occipital lobe; the LSpO2 was positively correlated with the MK in the bilateral parietal, precentral, and right postcentral cortex; the total score of MoCA scale was positively correlated with MK in the left hippocampus; the language function was positively correlated with MK in the white matter of left parietal lobe, and the delayed recall was positively correlated with the MK in right insula cortex and bilateral cingulate. After FDR correction, only the correlations of LSpO2 with right precentral gyrus cortex, and bilateral parietal cortex were significant. CONCLUSIONS: MK values of DKI imaging may provide valuable information in assessing the neurological impacts of obstructive sleep apnea.
RESUMO
<p><b>AIM</b>To elucidate the possible mechanisms underlying antiarrhythmia of the non-selective Na+/H+ exchanger inhibitor--amiloride.</p><p><b>METHODS</b>Single ventricular cells were isolated using a double-enzyme method. Effects of amiloride on voltage-dependent potassium and calcium currents in isolated guinea pig ventricular myocyte were recorded by using whole-cell patch clamp techniques.</p><p><b>RESULTS</b>Exposure to amiloride (10 -100 micromol x L(-1)), the L-type and T-type calcium currents were depressed. Amiloride resulted in a concentration-dependent inhibition of peak (Ca,L), But amiloride did not change the shape of their I - V curves. It only decreased the amplitudes of the currents of the two types. When myocytes were incubated with 100 micromol x L(-1) amiloride, I(Kr) was slightly depressed and I(Ks) did not change. Amiloride (1 - 100 micromol x L(-10) depressed I(K1) in a concentration-dependent manner.</p><p><b>CONCLUSION</b>Amiloride depressed potassium and calcium currents, which may give support to its uses in some diseases of the cardiovascular system.</p>
Assuntos
Animais , Feminino , Masculino , Amilorida , Farmacologia , Antiarrítmicos , Farmacologia , Canais de Cálcio Tipo L , Canais de Cálcio Tipo T , Separação Celular , Cobaias , Ventrículos do Coração , Biologia Celular , Miócitos Cardíacos , Técnicas de Patch-Clamp , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Trocadores de Sódio-HidrogênioRESUMO
<p><b>AIM</b>To investigate the effect of benzyltetrahydropalmatine (BTHP) on the rapidly activating component of delayed rectifier K+ current (Ikr) in single guinea pig ventricular myocytes.</p><p><b>METHODS</b>Whole-cell patch clamp technique was used to record Ikr.</p><p><b>RESULTS</b>Ikr was blocked by 1-100 mumol.L-1 BTHP in concentration-, voltage-, and specifically frequency-dependent fashion, with IC50 of 13.5 mumol.L-1 (95% confidence range: 11.2-15.8 mumol.L-1). 30 mumol.L-1 BTHP reduced Ikr and Ikr.tail by (31 +/- 4)% and (36 +/- 5)% (n = 6, P < 0.01), respectively. The time constant for deactivation (tau') of the tail current was decreased by 30 mumol.L-1 BTHP from (238 +/- 16) ms to (196 +/- 14) ms, while drug had no any effect on the time constant for activation (tau) of Ikr,tail.</p><p><b>CONCLUSION</b>BTHP inhibited Ikr in a frequency-dependent fashion.</p>