Neuroanatomical correlates of the near response: voluntary modulation of accommodation/vergence in the human visual system

This study identifies brain regions participating in the execution of eye movements for voluntary positive accommodation (VPA) during open-loop vergence conditions. Neuronal activity was estimated by measurement of changes in regional cerebral blood flow (rCBF) with positron emission tomography and 15O-water. Thirteen naive volunteers viewed a checkerboard pattern with their dominant right eye, while a lens interrupted the line of gaze during alternate 1.5 s intervals. Three counterbalanced tasks required central fixation and viewing of a stationary checkerboard pattern: (i) through a 0.0 diopter (D) lens; (ii) through a -5.0-D lens while avoiding volitional accommodation and permitting blur; and (iii) through a -5. 0-D lens while maintaining maximal focus. The latter required large-amplitude, high-frequency VPA. As an additional control, seven of the subjects viewed passively a digitally blurred checkerboard through a 0.0-D lens as above. Optometric measurements confirmed normal visual acuity and ability to perform the focusing task (VPA). Large-amplitude saccadic eye movements, verified absent by electro-oculography, were inhibited by central fixation. Image averaging across subjects demonstrated multifocal changes in rCBF during VPA: striate and extrastriate visual cortices; superior temporal cortices; and cerebellar cortex and vermis. Decreases in rCBF occurred in the lateral intraparietal area, prefrontal and frontal and/or supplementary eye fields. Analysis of regions of interest in the visual cortex showed systematic and appropriate task dependence of rCBF. Activations may reflect sensorimotor processing along the reflex arc of the accommodation system, while deactivations may indicate inhibition of systems participating in visual search.     

Linking genes and environmental exposure: why China presents special opportunities

The Human Genome Project will have an enormous impact on our ability to study and understand human disease by providing maps of human genes. However, many of the most prevalent human diseases result from the complex interaction of numerous genes. Even with the use of a catalogue of human genes, the task of analyzing complex genetic and environmental interactions involved in the common human disorders will be formidable. Due to its demographic specificities and large size, the Chinese population offers a unique resource for the study of human genetics and the ability to capitalize upon the recent revolution in biotechnology. Reasons that China provides an exceptional population for genetic studies of complex diseases include: (i) the resource of 1.3 billion people makes obtaining a large number of subjects with rare (and common) diseases possible; (ii) relative genetic homogeneity in many regions has been preserved; (iii) stratification is distinct; (iv) urban/rural and geograph ic contrasts, both in environmental factors and disease occurrence, are quite marked; (v) family members tend to stay congregated; and (vi) epidemiologic study is cost-beneficial.     

Use of electron spectroscopic imaging to determine element composition of the melanin granules in the stria vascularis of the guinea pig

Electron spectroscopic imaging (ESI) was used to analyze the element content of melanin granules in the stria vascularis seen in ultrathin sections of Spurr-embedded cochleae of the guinea pig. To determine element composition, ESI images were taken at different ionization edges, and non-specific background signals were subtracted digitally by an image processing system. The presence of calcium and nitrogen in the melanin granules could be demonstrated clearly. The calcium identified in the melanin granules was then compared with the spatial distributions of calcium binding sites after the application of an antimonate precipitation method, which was used to localize loosely bound calcium. Despite a high calcium concentration within the granules, only very small single scattered calcium precipitates could be detected between these structures as compared with the amount of calcium precipitates attached to the plasma membrane or located within the cell nuclei. The nearly complete absence of precipitates within the melanin granules after the application of antimonate suggests differences in calcium binding and mobility involved in various physiological processes of ion balance regulation within the stria vascularis. Received: 14 October 1997 / Accepted: 11 February 1998     

Localization of epitopes in the toxins of Tityus serrulatus scorpions and neutralizing potential of therapeutic antivenoms.

Overlapping pentadecapeptides covering the complete amino acid sequence of TsII, TsVII and TsIV toxins from the venom of scorpion Tityus serrulatus (Ts), were prepared by use of the Spot method of multiple peptide synthesis. Horse anti-Ts antisera for therapeutic use were tested for their binding to peptides. All nine antisera tested showed reactivity with several peptides from the three toxins. Three antigenic regions, one in the very N-terminal, the second in the central part and the other in the C-terminal part of the three toxins were frequently, but not constantly recognized, with an intensity that seemed to be related to the neutralizing potency of the tested antivenom. Thus the corresponding peptides (residues 1-15 and 48-62 of TsII; residues 1-15, 16-30 and 48-62 of TsIV and residues 1-15 and 47-61 of TsVII) were synthesized, coupled to KLH and used as antigens to coat the microtitration plates to determine any relationship between their ELISA reactivity with therapeutic horse antivenoms and the neutralizing potential of these antivenoms. The mixture of the N-terminal peptide of TsII, of the N-terminal TsVII peptide and of the C-terminal of TsIV was found to give a linear relationship with the neutralizing titer of horse serum of low neutralizing potency (< or =1 mg/ml). However, high neutralizing antivenoms did not show the expected response in peptide ELISA. This observation is discussed in the context of the occurrence of continuous and discontinuous epitopes on toxins.     

Gene mapping of SEZ group genes and determination of pentylenetetrazol susceptible quantitative trait loci in the mouse chromosome

Gene mapping of the newly discovered SEZ genes (seizure-related genes) in the mouse was performed by linkage analysis. SEZ6 was on chromosome 11, SEZ12 on chromosome 16, SEZ15 on chromosome 3 and SEZ17 (PTZ17) on chromosome 18. The mouse chromosomal locus related to high susceptibility to pentylenetetrazol (PTZ) was also determined by linkage analysis using the recombinant inbred mouse, BXD (C57BLxDBA). A significant level of PTZ susceptibility was found on chromosome 2. Chromosomal loci of the newly discovered SEZ genes were not coincident with the significant chromosomal loci to PTZ susceptibility. Since epilepsy is assumed to be a disease syndrome which is probably manifested by abnormal expression of multifocal genes, determination of the role of each chromosomal locus in the provocation of seizure activity is important.     

Usefulness and Pitfalls of Intraoperative Spinal Motor Evoked Potential Recording by Direct Cortical Electrical Stimulation

Summary ? Objective. The aim of this study is to investigate the usefulness and problems with spinal motor evoked potential (MEP) recording, especially the reasons for failed recording. We report our personal experience over the last 8 years in patients with lesions adjacent to the primary motor cortex. Methods. MEP records of 50 consecutive patients were retrospectively reviewed. MEP was recorded by a catheter electrode inserted in the cervical epidural space. Stimulation electrodes were placed on the cortical surface during surgery. SEP recording was also performed in 29 of 50 patients. Results. MEP was obtained in 40 cases, and SEP was recorded in all 29 cases. The central sulcus was identified in 93% of patients in whom both MEP and SEP were performed, whereas in only 86% of patients who underwent only MEP. The main reason for MEP failure were inadequate exposure of the motor cortex, pre-existing hemiparesis and technical errors. Postoperative deterioration of motor function was closely related to intra-operative MEP changes. Conclusion. MEP is a useful tool to determine the motor cortex and to predict postoperative motor function. However, precise pre-operative craniotomy planning and combination with intra-operative SEP is essential to reduce the MEP failure.     

Spontaneous closure of ventricular septal defects followed up from <3 months of age

BACKGROUND: This study evaluates the incidence and timing of spontaneous closure (SC) of ventricular septal defect (VSD) using Doppler color flow mapping. METHODS: A total of 225 infants (mean age 30 days) were diagnosed with uncomplicated VSD: 31 (14%) subpulmonary VSD, 159 (70%) perimembranous, and 35 (16%) muscular. The patients were divided into two groups according to the presence or absence of congestive heart failure (CHF). SC was confirmed with color Doppler. RESULTS: Surgical closure was performed in 59 patients (26%). SC occurred in 107 patients (48%); three (10%) of 31 with subpulmonary VSD, 75 (47%) of 159 with perimembranous VSD, and 29 (83%) of 35 with a muscular VSD. Average age at SC was 19 months. In three SC patients with a subpulmonary VSD, there was no aortic valve prolapse and no aortic regurgitation. SC occurred in 96% of SC patients with a perimembranous VSD by the age of 6 years, and in 93% of those with a muscular VSD by the age of 3 years. In patients without CHF, the rate of SC was 72%; 23% in subpulmonary VSD, 74% in perimembranous, and 85% in muscular. SC occurred in only 23% of patients with a perimembranous VSD with CHF. Mean age at the final examination was 6.9 years in 59 patients with a VSD remaining open, and 63% of patients with a perimembranous VSD remaining open had an aneurysm of the ventricular membranous septum. CONCLUSIONS: The SC rate of VSD by mean age of 6.9 years was 48%, but it was 72% in patients without CHF. In patients with CHF, SC was seen only in patients with a perimembranous VSD. The rate of SC was 10% in subpulmonary VSD. The authors contend that SC probably occurred by growth of muscular septum surrounding VSD. Muscular VSD spontaneously closed earlier than perimembranous VSD.     

非接触心内膜激动标测系统指导疑难心律失常消融的临床研究

目的 研究非接触心内膜激动标测系统指导疑难心律失常的标测与消融的有效性与优越性。方法 12例患者，男性9例，女性3例，年龄28-76岁，电生理检查为右室特发性室性早搏1例，左室特发性室性心动过速2例，左房房性心动过速1例，右房房性心动过速2例，左房心房颤动6例．其中4例常规电生理标测消融末成功，1例成功后复发．经股静脉置入64极球囊电极和射频消融导管至同一心腔．计算机标测系统首先构建心腔几何构型，然后建立心动过速的腔内等电势图，分析心动过速的起源点及关键峡部，利用计算机导航系统指导消融导管至拟定靶点处进行消融，结果 1例起源于右室流出道偏间隔的室性早搏患者行片状消融获得成功；2例左室特发性室性心动过速标测其心动过速起源于左后中间隔及左后间隔区域行片状消融成功；1例左房房性心动过速标测其心动过速起源于右肺下静脉间隔部并指引消融导管行右肺下静脉至二尖瓣之间线性消融获得成功；2例右房房性心动过速巾1例标测其最早激动点位于下腔静脉口，此处行环状消融获得成功，另1例位于上腔静脉后方穿过界嵴中部线性消融获得成功；6例左房房颤患者1例在窦性心律卜标测其敛房颤房早起源于左右上肺静脉之间，行线性消融成功，另5例在房颤发作下标测其房颤起源折返部位，分别行右上下肺静脉、左上下肺静脉、左右上肺静脉之间、左下肺静脉与二尖瓣峡部之间线件消融成功，12例患者术中、术后均无并发症，随访2—26个月，无1例复发．结论 非接触心内膜激动标测系统指导心律失常的心内膜标测与消融是安全有效的，对复杂、难治性心律失常的电生理机制的阐明和指导消融具有较好的临床应用价值，     

Paget''s disease of the vulva: clinicopathologic study of type 1 cases treated at a single institution

The aim of this study was to evaluate clinicopathologic characteristics of primary cutaneous Paget's disease of the vulva. Between 1986 and 2005, 22 patients with primary cutaneous Paget's disease of the vulva (type 1) were treated at Tohoku University Hospital. Medical records were reviewed for pathologic diagnosis, patient age, associated neoplasms, type(s) of eczema, symptom duration, treatment, surgical procedures, recurrence, and length of follow-up. Patient age ranged from 51 to 85 years (median 71.5 years). Median duration of symptoms was 24 months (range 2-60 months). Type 1a (intraepithelial) Paget's disease accounted for 18 patients, with 3 type 1b (invasive) cases and 1 type 1c (intraepithelial disease with underlying adenocarcinoma) case. Mean length of follow-up was 53.7 months, and median follow-up was 49 months (range 6-199 months). Only two patients had an associated internal malignancy: T-cell leukemia and breast cancer. Mapping biopsy was performed in 14 of the 18 type 1a cases. All patients were free of disease at the surgical margins and are alive without recurrence. The four patients with type 1b or 1c disease had lymph node metastases. Two has died of disease, and two are alive with no recurrence. The rate of secondary malignancy seems to be low in primary cutaneous Paget's disease of the vulva. Mapping biopsy with careful examination of characteristic skin surface may be useful for surgery of type 1a cases. Inguinal lymphadenectomy is recommended in cases with question of invasion or known underlying adenocarcinoma.     

Rethinking children’s public health: the development of an assets model

It has been suggested that asset-based strategies could provide an opportunity to rethink the approach to public health; however, this may not be a viable option unless there is clear recognition of specific individual assets. Although there has been some consideration of assets within a child health context, this is limited and previous studies have not sought to identify assets from the perspective of the child. This paper reports on a study that drew on an ethnographic approach, using a photo-elicitation method, to facilitate the mapping of children’s internal and external assets from the viewpoint of children themselves. Two primary schools in the South-East of England were used to recruit 20 year five children (aged 9–11 years of age). The participants, 10 boys and 10 girls, were given disposable cameras and asked to take photographs of the activities that they enjoyed. The children’s photographs were used as prompts during individual semi-structured interviews. A constant comparative analysis facilitated the mapping of the children’s assets as the children described them; this process revealed one overall stabilising asset (‘My Family’) as well as eight internal and three external assets. All of the assets are presented within an original model, ‘I’m good’: the children’s asset wheel [CAW], which was developed from the findings. It is suggested that the CAW could complement previous asset-based work to facilitate the rethinking of approaches to the enhancement of children’s public health.