原癌基因BMI-1的研究进展

BMI-1(B-cell specific moloneyleukemia virusinsertion site 1,BMI-1)是PcG(Polycomb group,PcG)家族的一员,同时也是一种原癌基因,与c-myc一起参与小鼠T、B细胞淋巴瘤的发生。选择性敲除BMI-1可导致出生后进行性发育迟缓、神经系统异常和严重的造血缺陷等。本文就原癌基因BMI-1的研究进展作一综述。1 PcG家族的概述PcG基因家族最初是在果蝇体内作为HOX的抑制因子被鉴定出,迄今为止已发现30~40种PcG基因,它们协同作用以维持机体内细胞的转录抑制状态。PcG家族调节许多生命过程中的基因表达,包括造血、前后轴形成以及调控靶基…     

Multi-level basis selection of wavelet packet decomposition tree for heart sound classification

Wavelet packet transform decomposes a signal into a set of orthonormal bases (nodes) and provides opportunities to select an appropriate set of these bases for feature extraction. In this paper, multi-level basis selection (MLBS) is proposed to preserve the most informative bases of a wavelet packet decomposition tree through removing less informative bases by applying three exclusion criteria: frequency range, noise frequency, and energy threshold. MLBS achieved an accuracy of 97.56% for classifying normal heart sound, aortic stenosis, mitral regurgitation, and aortic regurgitation. MLBS is a promising basis selection to be suggested for signals with a small range of frequencies.     

BMI-1基因与肿瘤关系的研究进展

BMI－1基因是PCG家族的重要成员之一,是一种原癌基因,最初于1991年在鼠淋巴瘤中被发现。经过几十余年的研究,日前已对BMI－1的基因分子结构、所编码氨基酸序列以及与胚胎发育的关系有了更深一步的认识。近年来,人们发现BMI－1与肿瘤的发生、发展关系密切,BMI－1基因与肿瘤关系之间的研究更是近年来的研究热点。     

基于小波多分辨分析的第一第二心音提取

在心音信号的分析中,为了有针对性的分析第一心音(S1)、第二心音(S2)、第三心音(S3)、第四心音(S4),首先需要将它们从采集的心音信号中分离出来.本文提出一种方法,利用小波多分辨分析,提取第一心音及第二心音的同步信号,从而完成对第一心音和第二心音的实时分离.该方法区别于传统的依靠心电信号进行同步提取第一心音和第二心音的方法,避免了采集心音信号的同时需采集心电信号的麻烦,也提供了一种实现信号自同步的思路.用本方法对28例心音信号进行了仿真实验,1、S2均能被正确地分离出,表明该方法是可行的.     

Modeling of heart systolic murmurs based on multivariate matching pursuit for diagnosis of valvular disorders

Heart murmurs are pathological sounds produced by turbulent blood flow due to certain cardiac defects such as valves disorders. Detection of murmurs via auscultation is a task that depends on the proficiency of physician. There are many cases in which the accuracy of detection is questionable. The purpose of this study is development of a new mathematical model of systolic murmurs to extract their crucial features for identifying the heart diseases. A high resolution algorithm, multivariate matching pursuit, was used to model the murmurs by decomposing them into a series of parametric time–frequency atoms. Then, a novel model-based feature extraction method which uses the model parameters was performed to identify the cardiac sound signals. The proposed framework was applied to a database of 70 heart sound signals containing 35 normal and 35 abnormal samples. We achieved 92.5% accuracy in distinguishing subjects with valvular diseases using a MLP classifier, as compared to the matching pursuit-based features with an accuracy of 77.5%.     

Distinct patterns of neuronal inputs and outputs of the juxtaparaventricular and suprafornical regions of the lateral hypothalamic area in the male rat

We have analyzed at high resolution the neuroanatomical connections of the juxtaparaventricular region of the lateral hypothalamic area (LHAjp); as a control and in comparison to this, we also performed a preliminary analysis of a nearby LHA region that is dorsal to the fornix, namely the LHA suprafornical region (LHAs). The connections of these LHA regions were revealed with a coinjection tract-tracing technique involving a retrograde (cholera toxin B subunit) and anterograde (Phaseolus vulgaris leucoagglutinin) tracer. The LHAjp and LHAs together connect with almost every major division of the cerebrum and cerebrospinal trunk, but their connection profiles are markedly different and distinct. In simple terms, the connections of the LHAjp indicate a possible primary role in the modulation of defensive behavior; for the LHAs, a role in the modulation of ingestive behavior is suggested. However, the relation of the LHAjp and LHAs to potential modulation of these behaviors, as indicated by their neuroanatomical connections, appears to be highly integrative as it includes each of the major functional divisions of the nervous system that together determine behavior, i.e., cognitive, state, sensory, and motor. Furthermore, although a primary role is indicated for each region with respect to a particular mode of behavior, intermode modulation of behavior is also indicated. In summary, the extrinsic connections of the LHAjp and LHAs (so far as we have described them) suggest that these regions have a profoundly integrative role in which they may participate in the orchestrated modulation of elaborate behavioral repertoires.     

Longitudinal loss of gray matter volume in patients with first-episode schizophrenia: DARTEL automated analysis and ROI validation

Region of Interest (ROI) longitudinal studies have detected progressive gray matter (GM) volume reductions in patients with first-episode schizophrenia (FESZ). However, there are only a few longitudinal voxel-based morphometry (VBM) studies, and these have been limited in ability to detect relationships between volume loss and symptoms, perhaps because of methodologic issues. Nor have previous studies compared and validated VBM results with manual Region of Interest (ROI) analysis.In the present VBM study, high-dimensional warping and individualized baseline-rescan templates were used to evaluate longitudinal volume changes within subjects and compared with longitudinal manual ROI analysis on the same subjects. VBM evaluated thirty-three FESZ and thirty-six matched healthy control subjects (HC) at baseline (cross-sectionally) and longitudinally evaluated 21 FESZ and 23 HC after an average of 1.5 years from baseline scans. Correlation analyses detected the relationship between changes in regional GM volumes in FESZ and clinical symptoms derived from the Brief Psychiatric Rating Scale, as well as cognitive function as assessed by the Mini-Mental State Examination.At baseline, patients with FESZ had significantly smaller GM volume compared to HC in some regions including the left superior temporal gyrus (STG). On rescan after 1.5 years, patients showed significant GM volume reductions compared with HC in the left STG including Heschl's gyrus, and in widespread brain neocortical regions of frontal, parietal, and limbic regions including the cingulate gyrus. FESZ showed an association of positive symptoms and volume loss in temporal (especially STG) and frontal regions, and negative symptoms and volume loss in STG and frontal regions. Worse cognitive function was linked to widespread volume reduction, in frontal, temporal and parietal regions. The validation VBM analyses showed results similar to our previous ROI findings for STG and cingulate gyrus. We conclude FESZ show widespread, progressive GM volume reductions in many brain regions. Importantly, these reductions are directly associated with a worse clinical course. Congruence with ROI analyses suggests the promise of this longitudinal VBM methodology.     

Direct Chill Casting and Extrusion of AA6111 Aluminum Alloy Formulated from Taint Tabor Scrap

AA6111 aluminum automotive body-sheet alloy has been formulated from 100% Taint Tabor scrap aluminum. Direct chill casting with and without high shear melt conditioning (HSMC) was used to produce the AA6111 alloy billets. Both homogenized and non-homogenized billets were extruded into sheets. The optical micrographs of the melt conditioned direct chill (MC-DC) samples showed refined equiaxed grains in comparison to direct chill (DC) cast and direct chill grain refined (DC-GR) samples. Optical metallography showed extensive peripheral coarse grain (PCG) for the DC, DC-GR and MC-DC planks extruded from the homogenized standard AA6111 billets while planks extruded from modified AA6111 billets (with recrystallization inhibitors) showed thin PCG band. The co-addition of recrystallization inhibitors Mn, Zr, and Cr with elimination of the billet homogenization step had a favorable impact on the microstructure of the AA6111 alloy following the extrusion process where a fibrous grain structure was retained across the whole section of the planks. The mechanical properties of as-cast planks extruded from non-homogenized billets were similar to those extruded from homogenized billets. Eliminating the homogenization heat treatment step prior to extrusion has important ramifications in terms of processing cost reduction.     

Long-Term Surgical Outcomes of Primary Congenital Glaucoma in China

OBJECTIVE:

To evaluate the long-term outcomes of three surgical procedures for the treatment of primary congenital glaucoma (PCG).

INTRODUCTION:

PCG is one of the main causes of blindness in children. There is a paucity of contemporary data on PCG in China.

METHODS:

A retrospective study of 48 patients (81 eyes) with PCG who underwent primary trabeculectomy, trabeculotomy, or combined trabeculotomy and trabeculectomy (CTT).

RESULTS:

All patients were less than 4 years (yrs) of age, with a mean age of 2.08 ± 1.23 yrs. The mean duration of follow-up was 5.49 ± 3.09 yrs. The difference in success rates among the three surgical procedures at 1, 3, 6 and 9 yrs was not statistically significant (p = 0.492). However, in patients with over 4 yrs of follow-up, Kaplan-Meier survival analysis revealed that the success rates of trabeculectomy and CTT declined more slowly than that of trabeculotomy. Among the patients, 66.22% acquired good vision (VA ≥ 0.4), 17.57% acquired fair vision (VA = 0.1 – 0.3), and 16.22% acquired poor vision (VA < 0.1). The patients with good vision were mostly in the successful surgery group. Myopia was more prevalent postoperatively (p = 0.009). Reductions in the cup-disc ratio and corneal diameter were only seen in the successful surgery group (p = 0.000). In addition, the successful surgery group contained more patients that complied with a regular follow-up routine (p = 0.002).

DISCUSSION:

Our cases were all primary surgeries. Primary trabeculectomy was performed in many cases because no treatment was sought until an advanced stage of disease had been reached.

CONCLUSIONS:

In contrast to most reports, in the present study, trabeculectomy and CTT achieved higher long-term success rates than trabeculotomy. The patients with successful surgical results had better vision. Compliance with a routine of regular follow-up may increase the chances of a successful surgical outcome.     

A ‘Third Way’ for lay involvement: what evidence so far?

Aims and objectives  This article considers evidence regarding lay involvement in the NHS, following the White Paper's commitment to rebuild public confidence in an NHS 'accountable to patients and open to the public and shaped by their views'. It looks at two aspects of lay involvement: the lay board member's involvement in primary care group (PCG) decision-making and the engagement of the PCG with the wider public.
Methods  The paper analyses data from the first sweep of the annual Tracker Survey of a sample of PCGs in England, led by the National Primary Care Research and Development Centre in collaboration with the King's Fund between September and December 1999. It draws specifically from the postal questionnaires sent to lay members. Firstly, however, it contextualizes this data by reviewing the history of lay involvement before 1997 in the NHS and particularly in primary care.
Conclusions  The paper concludes that, during the first 6 months of their operation, the lay voice was faintly heard in PCGs. The lay member's role in decision-making at board-level was peripheral. The majority rated their involvement in key aspects of decision-making as low and their influence on decision-making below that of other board members including the Chief Officer, the chair and the GP board members. Beyond the arena of the board, what little contact there was with the lay voice has taken the shape of informing rather than consulting. Mitigating factors include the early stage at which the survey was completed and the lack of precedents for lay involvement in primary care in a broad sense on which PCGs can draw.