Heterogeneity in 1H-MRS profiles of presymptomatic and early manifest Huntington's disease

OBJECTIVE: To evaluate (1)H-MRS profiles of the putamen in presymptomatic and manifest Huntington's disease (HD) patients for spectroscopic markers that are reliable, consistent signs of early pathology and to look for hemispheric differences as signs of use activation in an accelerated degradative process of the dominant hemisphere. METHODS: A short echo time Point RESolved Spectroscopy (PRESS) spectroscopic imaging study was performed at low field (0.5 Tesla, T) on 27 right-handed patients (17 presymptomatic gene carriers and 10 manifest patients of less than 3 years from clinical onset) and 10 right-handed normal volunteers. Spectra from individual voxels (0.56 cm(3)) in the putamen were selected for analysis. Resonance areas of peaks were normalized to water as a concentration standard. Interhemispheric comparisons were made in individuals in all three groups to look for hemispheric differences. RESULTS: Two presymptomatic patients showed normal spectra but all other HD patients displayed some combination of reduced N-acetylaspartate (NAA), enhanced glutamate/glutamine (Glx) activity, and lactate (Lac) elevations or reduced creatine (Cr). Rather than showing any one metabolite as pathognomonic of early change, spectroscopic profiles showed heterogeneity between HD patients. Low creatine was common in the presymptomatic but not in the manifest group. Hemispheric ratios of abnormal metabolites showed lower values of NAA and Glx in the dominant hemisphere in all three groups but values of creatine were selectively lower in the dominant hemisphere of only the presymptomatic patients. Lac was elevated in both hemispheres but less so in the dominant hemisphere in all HD patients. CONCLUSIONS: (1)H-MRS profiles from the putamen of presymptomatic and manifest patients reflect heterogeneity in pathophysiology. With the possible exception of low creatine in presymptomatic patients (1)H-MRS spectra are not suggestive of hemispheric differences supportive of an overall accelerated degradative process in the dominant hemisphere.     

Dimensions of intelligence in schizophrenia: evidence from patients with preserved, deteriorated and compromised intellect

There is a growing literature describing a subgroup of "high-functioning" people with schizophrenia who show preserved intellectual ability (IQ). A detailed characterisation of the cognitive abilities of this group may be important in targeting appropriate treatment, management and services for patients with schizophrenia. It is a widely held belief that variation in cognitive processing speed is the basis of individual differences in intelligence. The main objective of this study was to identify subgroups of schizophrenia patients with preserved (N=45), deteriorated (N=47) and compromised (N=17) intellect in order to study whether these subgroups differ in specific cognitive abilities (e.g. executive functions) or in general cognitive processing speed, as measured with an inspection time (IT) task. The patients who displayed an average estimated premorbid IQ, with no evidence of IQ decline (premorbid-current IQ difference <10 points), were found to show better performance on measures of executive function (continuous performance task, verbal fluency) compared with patients in the deteriorated and compromised subgroups. Nevertheless, this represented significantly impaired performance relative to healthy controls. In contrast, the average inspection times of patients with preserved IQ were as slow as those obtained in the deteriorated or compromised groups, indicating that high functioning patients are impaired in terms of cognitive processing speed. Furthermore, the average IT for all schizophrenia groups was significantly slower than that of healthy controls. These findings suggest that high functioning patients with schizophrenia exhibit enduring cognitive difficulties that may impact on their ability to benefit from rehabilitation interventions.     

Unevenness of ventilation assessed by the expired CO(2) gas volume versus V(T) curve in asthmatic patients

Recently, we have shown that the expired CO2 gas volume versus tidal volume (VCO2-VT) curve is a useful tool for assessing unevenness of ventilation because it allows the separation of tidal volume into three functional compartments: (a) the CO2-free expired air (V0), (b) the transitional volume (Vtr), (c) the alveolar volume (VA) and the measurement of alveolar FCO2 during resting breathing in normal subjects and patients with COPD. In this paper, we have investigated whether changes pertaining to unevenness of ventilation taking place immediately after the administration of methacholine can be assessed using the VCO2-VT curve in asthmatic patients. The VCO2-VT curve was obtained during tidal breathing from 16 stable asthmatic patients who underwent a methacholine challenge test. It has been found that the Vtr, and hence Bohr's dead space (VD,Bohr = V0 + Vtr), over tidal volume ratios were significantly increased immediately after the methacholine administration, whilst the V0 over tidal volume ratio was not affected. The change of the above ratios was not related to the percentage decrease of FEV1.0 following methacholine administration.     

"Failure" of forearm intramedullary elastic nails

Elastic nails are an established modality for treating forearm fractures in children. These nails are usually removed 6–9 months after surgery as refracture may occur in 10% of cases if the nails removed earlier. We report a case of refracture of the forearm bones with elastic nails in situ, 5 months after the original fractures. The fracture was angulated approximately 80° with the apex pointing anteriorly. Closed reduction was difficult and resulted in breakage of the ulnar nail. The authors describe the details and outline the management of this unreported complication.     

Evaluation of techniques for treating the bleeding wound

BACKGROUND: Despite the fact that the urgent control of active bleeding from external body surfaces demands a basic procedure, it is puzzling that this topic has received little if any attention in modern medical research. Elastic adhesive dressing (ELAD) has been proposed for dressing the bleeding wound. METHODS AND MATERIALS: Three techniques were compared over a simulated wound in a human model. Pressures generated between the chosen dressing surface and the underlying mock wound's cutaneous surface, time consumption, convenience, satisfaction and pain were tested for each technique. RESULTS: Sixty-eight experiments were performed over nine separate anatomical sites. Average pressures for field dressing, ELAD and manual compression were 33, 88 and 180 mmHg, respectively; these differences in pressure were statistically significant. Manual pressure was equally inconvenient for both patient and caregiver. The more proximal and wider anatomical regions were more difficult and time consuming to compress. The caregivers graded ELAD the highest level of convenience and general satisfaction. CONCLUSIONS: Field bandage testing reflected its inadequacy in controlling bleeding from most body regions. The results suggest that ELAD may be the hands-free technique of choice. We hope that this article will stimulate further research and elicit evidence on precisely which technique is most suitable for various anatomical location.     

Changes with age in the distribution of a frailty index

Models of human mortality include a factor that summarises intrinsic differences in individual rates of ageing, commonly called frailty. Frailty also describes a clinical syndrome of apparent vulnerability. In a representative, cross-sectional, Canadian survey (n = 66,589) we calculated a frailty index as the mean accumulation of deficits and previously showed it to increase exponentially with age. Here, its density function exhibited a monotonic change in shape, being least skewed at the oldest ages. Although the shape gradually changed, the frailty index was well fitted by a gamma distribution. Of note, the variation coefficient, initially high, decreased from middle age on. Being able to quantify frailty means that health risks can be summarised at both the individual and group levels.     

Small Intestine Wall Distribution of Elastic Stiffness Measured With 500 MHz Scanning Acoustic Microscopy

Obtaining data relating intestinal mechanical properties and histology is a step towards the next level in the hierarchy of structure of living tissue, and may provide new insight into the mechanisms of intestinal function and disease such as obstruction. Due to lack of methodology, however, such data are currently sparse. Scanning acoustic microscopy (SAM) can measure the propagation speed of sound (C) and the acoustic impedance (Z) with micrometer resolution in tissue. By use of elementary theory of elasticity, the elastic stiffness (c₁₁) can be computed from C and Z. We used 5-m-thick transverse sections of ethanol treated guinea pig small intestine as the experimental model and measured the distribution of C and Z across the intestinal wall using SAM at 500 MHz. The individual layers mucosa, submucosa, and circular and longitudinal muscle were discerned with ease in the images and varied significantly with respect to both C and Z in most cases. The measured values (median values) of C ranged from 1550 to 1669 m s^–1, and Z ranged from 2.10 to 2.60 MPa s m^–1.c₁₁ differed between all layers ranging from 3.25 to 4.27 GPa with the following sequence of magnitude: circular muscle>submucosa>mucosa>longitudinal muscle (p < 0.001). In conclusion, we provided the first microscale mechanical data relating to the histological layers of the small intestine. © 2001 Biomedical Engineering Society. PAC01: 8719Rr, 4380Ev, 8719Ff, 4380Cs, 4335Yb, 4358Bh, 4358Ls     

Elastic properties of muscle-tendon complex in long-distance runners

The purpose of this study was to investigate the elastic properties of muscle-tendon complex (MTC) in knee extensor muscles and the capacity for elastic energy utilization in long-distance runners (LDR) by comparing with data obtained from untrained individuals (CON). The elongation (L) of the tendon and aponeurosis of vastus lateralis muscle during isometric knee extension was determined by real-time brightness mode ultrasonography, while the subjects developed a gradually increasing torque from 0 (relaxed) to maximal effort (MVC) within 7 s. In addition, performances in two kinds of maximal vertical jumps, i.e. squatting (SJ) and counter-movement jumps (CMJ), were measured. The relationship between L muscle and force (F ) was curvilinear and consisted of an initial region (toe region), characterized by a large increase in L with increasing F, immediately followed by a linear region. The slope of the regression equation for the L-F relationship in the range 50%–100% of MVC was defined as an index of MTC compliance, where the rate of the changes in L to that in muscle F at every 10% of MVC became almost constant. The maximal L (L _max) and MTC compliance were significantly lower in LDR than in CON: 29.9 (SD 3.9) mm in LDR compared to 33.3 (SD 5.5) mm in CON for L _max and 1.55 (SD 0.25) × 10⁻² mm · N⁻¹ in LDR compared to 1.88 (SD 0.82) × 10⁻² mm · N⁻¹ in CON for MTC compliance. Also, LDR showed significantly less elastic energy absorption (E _e) than CON, defined as the area below the L-F relationship curve from 0 to 100% of MVC. Not only jump heights but also the differences between the heights in SJ and CMJ, expressed as the percentage of the height in SJ, were significantly lower in LDR than in CON. The augmentation with counter-movement was significantly correlated to either MTC compliance (r = 0.554, P < 0.05) or E _e (r = 0.563, P < 0.05). Thus, the present results would indicate that MTC of vastus lateralis muscle is less compliant and its potential for energy storage during MTS lengthening is lower in LDR than untrained individuals. These elastic profiles of vastus lateralis muscle in LDR may be associated with their lower performances during CMJ. Accepted: 3 September 1999     

食管癌多部位DNA含量分析及其临床意义

目的;探讨食管癌多部位ＤＮＡ含量与临床及病理特性之间的关系。方法：流工细胞光度术检测１００例食管癌手术切除新鲜标本的癌、癌旁和断端组织的ＤＮＡ含量。结果：癌组织ＤＮＡ非整倍体（ＡＮ）、ＤＮＡ指数（ＤＩ）和细胞增殖活性指数（ＰＩ）都显著高于癌旁和断端（Ｐ〈０．０５）;食管癌ＡＮ与肿瘤细胞分化和局部洒巴结转移密切相关（Ｐ〈０．０１）。在癌体与癌旁或断端组织间存在ＤＮＡ倍体异质性（１４．８％）;切距〈５     

Histologic architecture of submucosal connective tissues in human eustachian tube with supplemental reference to the effects of aging

Summary Serial sections of 74 human eustachian tubes from 37 autopsy cases were examined microscopically to determine the histologic architecture of submucosal connective tissues. Abundant elastic fibers ran just beneath the mucosal epithelium of the eustachian tube. Two kinds of layers of collagenous fiber were observed — an inner circular layer and an outer longitudinal layer. An elastic fiber band perfectly encircled the tubal lumen at the pharyngeal part of the eustachian tube. This band became less sharply defined at the osseous part. The two layers of collagenous fiber were contiguous, especially in the upper part of the tube, and ran from the pharyngeal orifice to the isthmus. Submucosal connective tissues were found to be undeveloped in fetal eustachian tubes. In children as well, elastic fibers were not fully developed, and circular banding of collagenous fibers was less marked. With advancing age, elastic fibers increased in number and became large and brittle. Both layers of collagenous fiber became thicker.The present data indicate that the submucosal connective tissues may play an important role in the elasticity of the eustachian tube itself and in the maintenance of the tubal framework. Gerontologic changes in the eustachian tube stroma have been considered pathophysiologically.