Amplitude and frequency analysis of force plate data in sitting children with and without MMC

OBJECTIVE. To investigate if force plate measurements can be used to detect postural sway differences in sitting children with and without myelomeningocele (spina bifida).BACKGROUND. The postural sway has not been investigated in children with myelomeningocele previously. Since many of these children are not able to stand independently, force plate measurements during sitting could be one way to detect differences in their postural sway compared to normal children. However, there is very little published regarding assessment of seated postural sway.METHODS. Force plate measurements on 15 six years old children with myelomeningocele and 20 age-matched normal children were analysed. The standard deviation and the median frequency of the horizontal ground reaction force were used to characterise the body sway.RESULTS. The standard deviation of the force was larger only for some of the children with myelomeningocele as compared to the control group. The median frequency was significantly lower in the myelomeningocele group as compared to the control group. Visual input and seat base inclination did not influence the postural sway significantly. CONCLUSIONS. The results show that frequency analysis can be used to detect fundamental differences in postural sway that can not be observed visually.RelevanceIn this paper a new method for analysis of seated postural sway is described. The lack of relatively high spectral frequencies for children with myelomeningocele shows that the output from the postural control system differs as compared to the control group.     

包膜活性炭吸附血液灌流清除人血浆中毒鼠强的实验

目的:观察包膜活性炭对血浆中毒鼠强的清除率及吸附规律。方法:实验于2004-05/2006-04在军事医学科学院毒物药物研究所国家重点实验室完成。采用包膜活性炭灌流器对毒鼠强血浆样进行血液灌流吸附,在灌流的1,2,3h分别取样,经乙酸乙酯萃取后,用气相色谱氮磷检测器法(GC/NPD)测定其含量并计算清除率。结果:活性炭对毒鼠强的吸附作用在血液灌流1h最高,灌流2h后毒鼠强质量浓度无明显变化。400,200μg/L毒鼠强血液灌流1h清除率分别为(57.83±1.85)%,(48.18±1.81)%。结论:用包膜活性炭吸附剂进行血浆的灌流吸附,能清除大部分毒物,迅速降低血浆中毒鼠强的质量浓度。     

Sensitization of trigeminal nociception specific for migraine but not pain of sinusitis.

Neurology. 2002;59:1450-1453.
Trigeminal pain processing was studied in 14 patients with unilateral migraine attacks and 14 age- and sex-matched patients with comparable unilateral headache from frontal sinusitis. Using a nociception-specific blink reflex method (nBR), a facilitation of nBR responses predominantly on the headache side was observed in migraine, but not in sinusitis. The facilitation of trigeminal nociception may be specific for migraine rather than a consequence of peripheral pain such as frontal sinusitis.
Comment: Here we have evidence for the central hyperexcitability of migraine, not found in the previously cited article by Boska et al. SJT     

ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis

Background  

Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance.     

The role of DTNBP1, NRG1, and AKT1 in the genetics of schizophrenia in Finland

Several putative schizophrenia susceptibility genes have recently been identified. Significant associations between schizophrenia and neuregulin 1 (NRG1) and dysbindin (DTNBP1) were first reported in 2002 and studies in several populations have since independently reported positive associations to these gene regions. Further, both tentative functional and genetic data have implicated the role of AKT1 in the genetic background of this disorder. However, findings have not been consistent in all populations. We investigated the allelic diversity of these three genes NRG1, DTNBP1 and AKT1 in a representative nation-wide study sample of 441 Finnish schizophrenia families consisting of 865 affected individuals, in order to assess their role in one of the largest population-based study samples. DTNBP1 and AKT1 failed to show evidence of association, whereas two SNPs in the 3' region of the NRG1 gene yielded suggestive evidence of association (p=0.012 and p=0.048) in family-based association analyses. Thus, our study does not indicate that AKT1 or DTNBP1 play a role in the etiology of schizophrenia in the Finnish population. Furthermore, results do not support a major role for NRG1, but we cannot completely exclude a minor role of this gene in the Finnish population.     

Disruption of Esrom and Ryk identifies the roof plate boundary as an intermediate target for commissure formation

Growth cones are guided to their final destination by intermediate targets. Here, we identify intermediate targets and signaling components acting on zebrafish habenula commissural axons. Live imaging establishes that axons pause at the medial habenula before and after crossing the roof plate. esrom mutants axons fail to advance beyond the ipsilateral medial habenula. Tsc2 function is reduced in mutant axons, indicating cell autonomous defects in signaling. Consistent with signaling properties changing outside the roof plate, EphB is surface localized on axon segments within a zone demarcated by the medial habenula. wnt4a is expressed in the medial habenula and morpholino knockdown causes loss of the commissure. Electroporation of truncated Ryk causes axons to reenter the midline after reaching the contralateral habenula. These data identify Esrom as a mediator of growth cone navigation at an intermediate target and underscore the importance of midline boundaries as signaling centers for commissure formation.     

Extracellular amino acid levels measured with intracerebral microdialysis in the model of posttraumatic epilepsy induced by intracortical iron injection

An iron induced model of posttraumatic chronic focal epilepsy in rats was studied with respect to extracellular amino acids, electrophysiology, and morphology, approx. 6 months after intracortical injection of ferrous chloride. Twenty-six of the twenty-eight (93%) rats developed spontaneous epileptiform EEG-activity and electrical cortical stimulation done in eight animals evoked seizure activity in five animals (62.5%). Epileptic brain tissue displayed significantly higher extracellular interictal levels of aspartate (ASP), compared to normal brain, measured with intracerebral microdialysis. The interictal levels of serine (SER) were significantly higher at the lesion side compared to the contralateral cortex in epileptic animals. Spontaneous elevations of ASP and glutamate (GLU) levels up to 8 times the basal level were found in 4/5 (80%). There was no consistent amino acid pattern following the electrically induced seizures, but in association with more intense seizure activity ASP and GLU were elevated. Histopathologically, the necrotic lesions in the cortex contained small vessels and iron pigment loaded astrocytes. Scattered eosinophilic neurons were found in the hippocampus, bilaterally in 37% of the animals. The results show that a focal epileptiform activity developed in a high percentage of animals that received an intracortical iron injection. The observed amino acid changes in epileptic animals may be involved in the development of seizures in this model of posttraumatic epilepsy.     

Pesticide assessment: Protecting public health on the home turf

Pesticide regulation is examined in the context of Health Canada’s Pest Management Regulatory Agency’s assessment of the chlorophenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) for turf. 2,4-D is the most common herbicide used to kill weeds in grass.The medical literature does not uniformly indicate harms from herbicides. However, the balance of epidemiological research suggests that 2,4-D can be persuasively linked to cancers, neurological impairment and reproductive problems. These may arise from 2,4-D itself, from breakdown products or dioxin contamination, or from a combination of chemicals.Regulators rely largely on toxicology, but experiments may not replicate exposures from 2,4-D application to lawns because environmental breakdown products (eg, 2,4-dichlorophenol) may not accumulate and selected herbicides are possibly less contaminated. Dioxins are bioaccumulative chemicals that may cause cancer, harm neurological development, impair reproduction, disrupt the endocrine system and alter immune function. No dioxin analyses were submitted to the Pest Management Regulatory Agency, and the principal contaminants of 2,4-D are not among the 17 congeners covered in pesticide regulation. Independent assessment of all dioxins is needed, in tissues and in the environment.The 2,4-D assessment does not approach standards for ethics, rigour or transparency in medical research. Canada needs a stronger regulator for pesticides. Potentially toxic chemicals should not be registered when more benign solutions exist, risks are not clearly quantifiable or potential risks outweigh benefits. Until landscaping pesticides are curtailed nationally, local bylaws and Quebec’s Pesticide Code are prudent measures to protect public health. Physicians have a role in public education regarding pesticides.     

Return of autologous blood donors as homologous blood donors

Autologous blood donors (ABDs) have been reported to have favorable attitudes toward returning as homologous blood donors (HBDs), but the frequency of return has not been well documented. ABDs eligible by history to be HBDs were followed at one blood center: 255 donating for elective surgery and 234 donating during pregnancy were followed for an average of 18 months and 20 months, respectively, from time of eligibility after surgery or postpartum. Male ABDs had a higher rate of return as HBDs, as 34 percent (21/62) returned to donate an average of 3 units, whereas 13 percent (56/427) of female ABDs returned as HBDs to donate an average of 2 units. Although a history of donation was associated with a higher rate of return (30%, 34/113), 11 percent (43/376) of ABDs with no history as HBDs returned to donate homologous units, despite having been recruited less frequently than prior HBDs. Overall, all male ABDs and female ABDs with an HBD history returned most frequently. The extra effort required for an autologous donor program may result in the recruitment of new donors into the HBD pool.     

In-111-labeled white blood cell uptake in noninfected closed fracture in humans: prospective study

Since indium-111 white blood cell (In-111 WBC) scintigraphy is often used to evaluate for osteomyelitis in bone fractures, it is important to know if noninfected fractures have In-111 WBC uptake. Twenty-seven noninfected closed fracture sites in 19 patients were prospectively evaluated with technetium-99m methylene diphosphonate bone scintigraphy and In-111 WBC scintigraphy. In-111 WBC uptake was present in 41% of the 27 sites. In the 11 positive sites, the In-111 WBC uptake was 1+ (definite but minimal) in 55%, 2+ (moderate) in 36%, and 3+ (marked) in 9%. The visual intensity of the radioactive uptake on In-111 WBC scintigrams relative to that on bone scintigrams was less in 82%, equal in 9%, and greater in 9%. The visual size of the area of uptake on In-111 WBC scintigrams and bone scintigrams was smaller in 36%, equal in 55%, and greater in 9%. Factors that may help distinction of In-111 WBC uptake due to fracture alone from infection associated with fracture are discussed.