Increased regional Hurst exponent reflects response inhibition related neural complexity alterations in pediatric bipolar disorder patients during an emotional Go-Nogo task.

Fractal patterns have been shown to change in resting- and task-state blood oxygen level-dependent signals in bipolar disorder patients. However, fractal characteristics of brain blood oxygen level-dependent signals when responding to external emotional stimuli in pediatric bipolar disorder remain unclear. Blood oxygen level-dependent signals of 20 PBD-I patients and 17 age- and sex-matched healthy controls were extracted while performing an emotional Go-Nogo task. Neural responses relevant to the task and Hurst exponent of the blood oxygen level-dependent signals were assessed. Correlations between clinical indices and Hurst exponent were estimated. Significantly increased activations were found in regions covering the frontal lobe, parietal lobe, temporal lobe, insula, and subcortical nuclei in PBD-I patients compared to healthy controls in contrast of emotional versus neutral distractors. PBD-I patients exhibited higher Hurst exponent in regions that involved in action control, such as superior frontal gyrus, inferior frontal gyrus, inferior temporal gyrus, and insula, with Hurst exponent of frontal orbital gyrus correlated with onset age. The present study exhibited overactivation, increased self-similarity and decreased complexity in cortical regions during emotional Go-Nogo task in patients relative to healthy controls, which provides evidence of an altered emotional modulation of cognitive control in pediatric bipolar disorder patients. Hurst exponent may be a fractal biomarker of neural activity in pediatric bipolar disorder.

Shared and specific patterns of structural and functional thalamo-frontal disturbances in manic and euthymic pediatric bipolar disorder.

Bipolar disorder (BD) is clinically defined by alternating depressive and manic episodes with a separated period of euthymia. Thalamo-frontal loop plays vital role in psychotic symptoms, altered motor control and executive difficulties in BD. It remains unclear that structural and functional alterations of thalamo-frontal loop among the different mood states in BD, especially in pediatric BD(PBD).Twenty manic PBD (mPBD), 20 euthymic PBD (ePBD) and 19 healthy controls (HCs) were included in the study. By analyzing the T1 images and fMRI signals, thalamus volume and frontal grey matter cortical thickness were tested, and functional connectivity (FC) between bilateral thalamus and frontal cortex was calculated. Relationship between clinical indices and thalamo-frontal FC was also evaluated in mPBD and ePBD adolescents.Compared to HCs, the cortical thickness of left middle frontal gyrus (MFG), bilateral superior frontal gyrus (SFG) was significantly decreased in both mPBD and ePBD patients, and volume of left thalamus and cortical thickness of right MFG significantly decreased in mPBD patients. Compared to that of the HCs and ePBD subjects, thalamo-frontal hyperconnectivity with MFG was found in mPBD, and compared with that of HCs, thalamo-frontal hypoconnectivity with precentral gyrus/SFG was found in ePBD. In ePBD patients, episode times positively correlated with FC values between thalamus and precentral gyrus.The findings of the present study demonstrate detailed knowledge regarding shared and specific structural and functional disruption in thalamo-frontal loop in mPBD and ePBD subjects. Thalamo-frontal abnormalities reported in adult BD subjects were also observed in adolescent BD patients, and thalamo-frontal dysfunction may be a crucial treatment target in BD.

Anterior segment optical coherence tomography of acute primary angle closure.

BACKGROUND: To assess anterior segment optical coherence tomographic measurements of patients after acute unilateral primary angle closure (APAC) compared with those of normal subjects. METHODS: The clinical observational study included 41 hospital-based patients after unilateral APAC, their unaffected contralateral eyes, and 205 subjects. These were selected from the population-based Beijing Eye Study, and were matched with the APAC group for age, gender, and refractive error. All study participants underwent slit-lamp adapted optical coherence tomography (OCT). RESULTS: Compared with the unaffected contralateral eyes, eyes with APAC had a significantly shallower anterior chamber (P < 0.001), smaller chamber angle (P < 0.001), shorter anterior chamber opening distance (P < 0.01), a more marked iris root curvature (P < 0.05), and a greater number of quadrants that were closed (P < 0.001). Compared with the control group, eyes with APAC and the unaffected contralateral eyes both showed more shallow anterior chambers (P < 0.001), smaller chamber angles (P < 0.001), shorter chamber opening distances in each quadrant (P < 0.001), and a greater number of quadrants that were closed (P < 0.001). The angle was most often closed in the nasal quadrant. In the APAC group, the anterior chamber angle was closed in three or more quadrants. CONCLUSIONS: Anterior segment OCT measurements show significant differences between eyes with APAC, contralateral eyes at risk for APAC, and normal eyes. This may open possibilities for a semi-automatic assessment of subjects at risk for APAC by anterior segment OCT. The anterior chamber angle was closed most often in the nasal quadrant, and, in APAC, the angle was closed in three or more quadrants.

[Development of a portable dynamic state ECG based on DSP].

The Portable dynamic state electrocardiogram collecting system is introduced by using TMS302VC5402, TLC320AD50C, liquid crystal display model, and so on. This dissertation describes the work principle of the system and uses the united algorithm based on wavelet to identify and locate the ECG characteristic waves. This system has as follows of advantages: big memory, low noise,high common mode rejection ratio, the low power consume,the long record time etc.

[Short time ECG signal analysis based on the reconstruction of phase space].

Based on the reconstruction of two-dimension phase space of time series of short ECG signals, the variation of the strange attractor geometry is described and two indices, VMI and VAI, are derived in this paper. The two indices can distinguish clearly the ECG signals of sinus rhythm, tachycardia and ventricular fibrillation. Stable results of VMI and VAI can be obtained by analyzing ECG signals of several seconds. They are expected to be used in the development of medical instruments for a fast realtime display of analysis results.

Anterior chamber depth and chamber angle and their associations with ocular and general parameters: the Beijing Eye Study.

PURPOSE: To investigate the normative data of anterior chamber depth (ACD) and angle width and their associations in Chinese adults. DESIGN: Population-based study. METHODS: The Beijing Eye Study 2006 included 3,251 subjects (73.3%) (aged 45+ years) out of 4,439 subjects who participated in the 2001 survey and who returned for reexamination. The subjects underwent an ophthalmologic examination including measurement of the anterior chamber dimensions by slit-lamp-based optical coherence tomography (OCT). RESULTS: Out of the 3,251 subjects, OCT measurements were available for 2,985 subjects (91.8%). Mean ACD measured 2.42 +/- 0.34 mm and the mean anterior chamber angle (ACA) was 38.3 +/- 16.3 degrees. In multivariate analysis, a shallow chamber depth was significantly associated with age (P < .001), hyperopic refractive error (P < .001), female gender (P < .001), short body stature (P = .003), nuclear cataract (P = .03), central corneal thickness [CCT] (P < .001), large optic disk (P < .001), and presence of chronic angle-closure glaucoma (P < .001). Correspondingly, a narrow ACA was associated with age (P < .001), female gender (P < .001), hyperopia (P < .001), nuclear cataract (P < .001), short body stature (P = .001), large optic disk (P < .001), and angle-closure glaucoma (P < .001). Chamber depth and angle width were not associated with presence of age-related maculopathy and diabetic retinopathy. CONCLUSIONS: A shallow anterior chamber and a narrow chamber angle in Chinese adults are associated with age, female gender, hyperopia, nuclear cataract, small optic disk, short body stature, CCT, and chronic angle-closure glaucoma. These data may be helpful to explain anatomic relationships of the anterior segment of the eye, and to elucidate risk factors of angle-closure glaucoma.