Pressure ulcers in trauma patients with suspected spine injury: a prospective cohort study with emphasis on device‐related pressure ulcers

Of all patients in a hospital environment, trauma patients may be particularly at risk for developing (device‐related) pressure ulcers (PUs), because of their traumatic injuries, immobility, and exposure to immobilizing and medical devices. Studies on device‐related PUs are scarce. With this study, the incidence and characteristics of PUs and the proportion of PUs that are related to devices in adult trauma patients with suspected spinal injury were described. From January–December 2013, 254 trauma patients were visited every 2 days for skin assessment. The overall incidence of PUs was 28·3% (n = 72/254 patients). The incidence of device‐related PUs was 20·1% (n = 51), and 13% (n = 33) developed solely device‐related PUs. We observed 145 PUs in total of which 60·7% were related to devices (88/145). Device‐related PUs were detected 16 different locations on the front and back of the body. These results show that the incidence of PUs and the proportion of device‐related PUs is very high in trauma patients.     

血清骨唾液酸蛋白的生物变异性研究

目的　骨唾液酸蛋白（Ｂｏｎｅ ｓｉａｌｏｐｒｏｔｅｉｎ,简称ＢＳＰ）是由成骨细胞分泌的一种非胶原蛋白质,反映骨转换和骨形成的指标。最近研究认为：血清ＢＳＰ浓度可反映破骨细胞活性和骨吸收过程,也可能是一个骨吸收指标。本实验测定了血清ＢＳＰ在人体内的生物变异性。方法　采用ＲＩＡ 法测定了２９０例不同性别和年龄的正常人血清ＢＳＰ的正常值,血清ＢＳＰ的天－天变异性及２４ ｈ 生物周期。　结果　在儿童组血清ＢＳＰ正常水平明显高于成人组,其最高值在新生儿期和青春期。绝经后妇女其血清浓度比绝经前妇女水平明显升高（Ｐ＜ ０．０５）。血清ＢＳＰ在每天同一时间的波动范围在 ７．３％ 至１７．７％ （平均１１．７％ ）。２４ ｈ 内有一个明显的生物周期性变化,表现为峰值在凌晨４～８ 时,然后逐渐下降直到午后１４时为最低。其生物周期的最大波幅为±２０％ ,（平均血浓度为１０．５ ｎｇ／ｍ ｌ）。结论　血清ＢＳＰ反映了骨转换的生理变化与年龄有明显相关性,其血清水平２４ ｈ 内有一个明显的生物周期,而天与天之间变异性较小。     

Immunohistochemical support for three putative transmitters in one neuron: Coexistence of 5-hydroxytryptamine,substance p- and thyrotropin releasing hormone-like immunoreactivity in medullary neurons projecting to the spinal cord

Using indirect immunofluorescence histochemistry, in part combined with the elution and restaining technique of Tramu, Pillez & Leonardelli (1978), the distribution of 5-hydroxytryptamine (5-HT), thyrotropin releasing hormone (TRH) and substance P immunoreactive neurons has been studied in the medulla oblongata and spinal cord of normal and colchicine-treated rats. Evidence was obtained that at least some cell bodies in the medullary raphe nuclei and adjacent areas contained all three compounds, 5-HT, TRH and substance P. Other cell bodies in the same areas may contain two or only one of these three putative transmitters. Alternatively, the intraneuronal levels of one or two of the substances may be too low to be detected with the present technique, in spite of the fact that colchicine treatment was used to elevate peptide levels in the cell somata.In a quantitative evaluation the proportion of 5-HT, TRH and substance P neurons was calculated at different levels and in different nuclei of the medulla oblongata. Out of all immunoreactive neurons, there were approximately twice as many 5-HT (56%) as TRH (23%) and substance P (21%) cells respectively, and this relation was also found in several major subnuclei, such as the nucleus raphe magnus and nucleus raphe obscurus. In the ‘arcuate’ region very high proportions of 5-HT cells (about 60–80%) were observed with only few substance P cells (2–12%). The ‘parapyramidal’ and ‘paraolivar’ regions, which include the nucleus interfascicularis hypoglossi, had more substance P (26–36%) than TRH (15–17%) cells. The most ‘even’ distribution was observed in the nucleus raphe pallidus (5-HT: 43%; TRH: 32%; substance P: 25%). The evaluation also indicated how the respective cell type (5-HT, TRH and substance P cells) distributed between the different subnuclei. Thus, at rostral levels the ‘suprapyramidal’ region contained a large proportion (about 30%) of the total numbers of counted 5-HT, TRH and substance P cells, respectively. Furthermore, the nucleus raphe magnus contained a large part (about 30%) of the TRH and substance P cells, but a smaller fraction (about 20%) of the 5-HT cells. Analysis of adjacent sections at regular intervals confirmed the overall quantitative evaluation. Generally, the distribution of 5-HT, TRH and substance P cells were roughly parallel. An exception was the midportion of the rostral medulla oblongata, where 5-HT cells were very numerous. Of particular interest was the fact that, especially in the nucleus raphe pallidus, there were in several series almost the same number of 5-HT, TRH and substance P cells, supporting the view that many cells in this nucleus contained all these compounds.In the spinal cord overlapping networks of 5-HT, TRH and substance P immunoreactive fibres were observed in the ventral horn. The number of 5-HT immunoreactive fibres seemed higher than the TRH and substance P immunoreactive ones. After treatment with the neurotoxins 5,6- or 5,7-dihydroxytryptamine there was an almost complete disappearance of all three types of fibres in the ventral horn, further supporting the occurrence of the two peptides in 5-HT neurons, either both of them together in the same 5-HT neuron or each of them in separate 5-HT neurons. It is, however, important to note that there are, in all probability, 5-HT neurons in the lower medulla oblongata which contain neither TRH nor substance P. Furthermore, in other brain regions there is no certain correlation between the distribution patterns of 5-HT, TRH and substance P immunoreactive cells.The results are consistent with the coexistence of 5-HT, TRH and substance P in neurons of the medulla oblongata that project to the spinal cord. Some neurons may contain detectable levels only of 5-HT and substance P, others only of 5-HT and TRH, while others contain all three substances. It can, however, not be excluded that some neurons contain only one of these compounds or that other combinations exist.     

Age-related changes of neuron numbers in the frontal cortex of a transgenic mouse model of Alzheimer's disease

Alzheimer’s disease (AD) is a neurodegenerative disorder, characterized by amyloid plaque accumulation, intracellular tangles and neuronal loss in selective brain regions. The frontal cortex, important for executive functioning, is one of the regions that are affected. Here, we investigated the neurodegenerative effects of mutant human amyloid precursor protein (APP) and presenilin 1 (PS1) on frontal cortex neurons in APP/PS1KI mice, a transgenic mouse model of AD, expressing two mutations in the human APP, as well as two human PS1 mutations knocked-in into the mouse PS1 gene in a homozygous (ho) manner. Although the hippocampus is significantly affected in these mice, very little is known about the effects of these mutations on selective neuronal populations and plaque load in the frontal cortex. In this study, cytoarchitectural changes were characterized using high precision design-based stereology to evaluate plaque load, total neuron numbers, as well as total numbers of parvalbumin- (PV) and calretinin- (CR) immunoreactive (ir) neurons in the frontal cortex of 2- and 10-month-old APP/PS1KI mice. The frontal cortex was divided into two subfields: layers II–IV and layers V–VI, the latter of which showed substantially more extracellular amyloid-beta aggregates. We found a 34% neuron loss in layers V–VI in the frontal cortex of 10-month-old APP/PS1KI mice compared to 2-month-old, while there was no change in PV- and CR-ir neurons in these mice. In addition, the plaque load in layers V–VI of 10-month-old APP/PS1KI mice was only 11% and did not fully account for the extent of neuronal loss. Interestingly, an increase was found in the total number of PV-ir neurons in all frontal cortical layers of single transgenic APP mice and in layers II–IV of single transgenic PS1ho mice between 2 and 10 months of age. In conclusion, the APP/PS1KI mice provide novel insights into the regional selective vulnerability in the frontal cortex during AD that, together with previous findings in the hippocampus, are remarkably similar to the human situation.     

Mechanism of acute tryptophan depletion: is it only serotonin?

The method of acute tryptophan depletion (ATD), which reduces the availability of the essential amino acid tryptophan (TRP), the dietary serotonin (5-hydroxytryptamine (5-HT)) precursor, has been applied in many experimental studies. ATD application leads to decreased availability of TRP in the brain and its synthesis into 5-HT. It is therefore assumed that a decrease in 5-HT release and subsequent blunted neurotransmission is the underlying mechanism for the behavioural effects of ATD. However, direct evidence that ATD decreases extracellular 5-HT concentrations is lacking. Furthermore, several studies provide support for alternative underlying mechanisms of ATD. This may question the utility of the method as a selective serotonergic challenge tool. As ATD is extensively used for investigating the role of 5-HT in cognitive functions and psychiatric disorders, the potential of alternative mechanisms and possible confounding factors should be taken into account. It is suggested that caution is required when interpreting ATD effects in terms of a selective serotonergic effect.     

Stimulation of osteogenic differentiation in human osteoprogenitor cells by pulsed electromagnetic fields: an in vitro study

Background  

Although pulsed electromagnetic field (PEMF) stimulation may be clinically beneficial during fracture healing and for a wide range of bone disorders, there is still debate on its working mechanism. Mesenchymal stem cells are likely mediators facilitating the observed clinical effects of PEMF. Here, we performed in vitro experiments to investigate the effect of PEMF stimulation on human bone marrow-derived stromal cell (BMSC) metabolism and, specifically, whether PEMF can stimulate their osteogenic differentiation.     

Nucleus accumbens and impulsivity

The multifaceted concept of impulsivity implies that different impulsivity aspects, mediated by different neural processes, influence behavior at different levels. The nucleus accumbens (NAc) is a key component of the neural processes regulating impulsivity. In this review, we discuss the findings of lesion studies in animals and functional imaging studies in humans focusing on the role of the NAc in impulsivity. Evidence supports that the extent and pattern of involvement of the NAc, and its subregions, the core and the shell, vary among different facets of impulsivity. Data from imaging studies reviewed in this article suggest the involvement of the ventral striatum/NAc in impulsive choice. Findings of animal studies indicate that lesions of the NAc core subregion facilitated impulsivity in tasks involving intertemporal choice, and promoted a risk-averse, less impulsive, tendency in tasks involving options with probability differences. Modification of neurotransmitter activity, especially of dopamine, which is proposed to underlie the changes observed in functional imaging studies, has been shown to influence afferent input pattern in the NAc and the generation of the behavioral output. Parameters of behavioral tasks reflecting response inhibition function are altered by neurochemical interventions and local electrical stimulation in both the core and the shell subregions. In toto, NAc's pattern of neuronal activity, either genetically determined or acquired, has a critical impact on the interindividual variation in the expression of impulsivity. Nevertheless, the NAc is not the only substrate responsible for impulsivity and it is not involved in each facet of impulsivity to the same extent.     

Hippocampal interneuron loss in an APP/PS1 double mutant mouse and in Alzheimer’s disease

Hippocampal atrophy and neuron loss are commonly found in Alzheimer’s disease (AD). However, the underlying molecular mechanisms and the fate in the AD hippocampus of subpopulations of interneurons that express the calcium-binding proteins parvalbumin (PV) and calretinin (CR) has not yet been properly assessed. Using quantitative stereologic methods, we analyzed the regional pattern of age-related loss of PV- and CR-immunoreactive (ir) neurons in the hippocampus of mice that carry M233T/L235P knocked-in mutations in presenilin-1 (PS1) and overexpress a mutated human beta-amyloid precursor protein (APP), namely, the APP^SL/PS1 KI mice, as well as in APP^SL mice and PS1 KI mice. We found a loss of PV-ir neurons (40–50%) in the CA1-2, and a loss of CR-ir neurons (37–52%) in the dentate gyrus and hilus of APP^SL/PS1 KI mice. Interestingly, comparable PV- and CR-ir neuron losses were observed in the dentate gyrus of postmortem brain specimens obtained from patients with AD. The loss of these interneurons in AD may have substantial functional repercussions on local inhibitory processes in the hippocampus.     

精液分析现状：对《亚洲男性学杂志》出版的陆金春等所著的“中国118 家实验室精液分析状况的调查”一文的评论

陆金春等[1]所著的"中国118家实验室精液分析状况的调查"一文主要回顾了当前在中国采用的精液分析方法.