Motor and cognitive deficits in apolipoprotein E-deficient mice after closed head injury

Previous studies suggest that traumatic brain injury is associated with increased risk factor for developing Alzheimer's disease. Furthermore, the extent of the risk seems to be most pronounced in Alzheimer's disease patients who carry the ε4 allele of apolipoprotein E, suggesting a connection between susceptibility to head trauma and the apolipoprotein E genotype. Apolipoprotein E-deficient mice provide a useful model for investigating the role of this lipoprotein in neuronal maintenance and repair. In the present study apolipoprotein E-deficient mice and a closed head injury experimental paradigm were used to examine the role of apolipoprotein E in brain susceptibility to head trauma and in neuronal repair. Apolipoprotein E-deficient mice were assessed up to 40 days after closed head injury for neurological and cognitive functions, as well as for histopathological changes in the hippocampus. A neurological severity score used for clinical assessment revealed more severe motor and behavioural deficits in the apolipoprotein E-deficient mice than in the controls, the impairment persisting for at least 40 days after injury. Performance in the Morris water maze, which tests spatial memory, showed a marked learning deficit of the apolipoprotein E-deficient mice when compared with injured controls, which was apparent for at least 40 days. At this time, histopathological examination revealed overt neuronal cell death bilaterally in the hippocampus of the injured apolipoprotein E-deficient mice.

The finding that apolipoprotein E-deficient mice exhibit an impaired ability to recover from closed head injury suggests that apolipoprotein E plays an important role in neuronal repair following injury and highlights the applicability of this mouse model to the study of the cellular and molecular mechanisms involved.     

Summation of fibre potentials and the e.m.g.-force relationship during the voluntary movement of a forearm

A linear mathematical model of the electromyogram (e.m.g.) has been developed for the biceps muscle. The number of motor units (and therefore muscle fibres) contributing to the resultant e.m.g. at any stage of movement has been found from the force analysis of elbow flexion. The depths of various motor units and the phase difference between the recruitment of any two motor units have been formulated using a spiral spread of recruitment sequence. The attenuation of individual motor-unit action potentials due to varying depths has been taken into consideration, and due regard has been taken of the length-tension diagram of a muscle while performing the force analysis. Attention has been focused on the flexion of the elbow joint, in which a method of finding the individual contribution of the biceps and brachialis muscles has been developed and applied. The results predicted by the model have been verified by experiments. The model can also be extended to the e.m.g. of other fast skeletal muscles. The conditions and limitations for such generalisations have been stated and discussed.     

Non-toxigenic Escherichia coli O157:H7 strain NCTC12900 causes attaching-effacing lesions and eae-dependent persistence in weaned sheep

Ruminants are regarded as a primary reservoir for Escherichia coli O157:H7, an important human pathogen. Intimin, encoded by the Locus of Enterocyte Effacement by E. coli O157:H7 organisms, has been cited as one bacterial mechanism of colonisation of the gastrointestinal tract. To confirm this and to test whether a non-toxigenic E. coli O157:H7 strain would colonise and persist in a sheep model, E. coli O157:H7 strain NCTC12900, that lacks Shiga toxin (stx) genes, was evaluated for use in a sheep model of persistence. Following oral inoculation of six-week-old sheep, persistent excretion of NCTC12900 was observed for up to 48 days. E. coli O157-associated attaching-effacing (AE) lesions were detected in the caecum and rectum of one six-week-old lamb, one day after inoculation. This is the first recorded observation of AE lesions in orally inoculated weaned sheep. Also, mean faecal excretion scores of NCTC12900 and an isogenic intimin (eae)-deficient mutant were determined from twenty-four six-week-old orally inoculated sheep. The eae mutant was cleared within 20 days and had lower mean excretion scores at all time points after day one post inoculation compared with the parental strain that was still being excreted at 48 days. Tissues were collected post mortem from animals selected at random from the study groups over the time course of the experiment. The eae mutant was detected in only 1/43 samples but the parental strain was recovered from 64/140 samples primarily from the large bowel although rumen, duodenum, jejunum, and ileum were culture positive especially from animals that were still excreting at and beyond 27 days after inoculation.     

Secretory role for human uterodomes (pinopods): secretion of LIF

The differentiation of human endometrial epithelium is a dynamic event, which occurs throughout the menstrual cycle in preparation for pregnancy. The appearance of uterodomes (pinopods) in this regard was first introduced in rodents with an established pinocytotic function, whereas little evidence was available in humans in this context. This study was undertaken to identify the potential physiological roles of uterodomes in the implantation process. To address this, endometrial biopsies from early, mid- and late luteal phases of the menstrual cycle of 23 fertile female patients with regular menses were used. Scanning and transmission electron microscopies (SEM and TEM) as well as immunofluorescence and immunogold TEM were performed to study the morphological changes and the expression pattern of leukaemia inhibitory factor (LIF) at uterodomes. Our results illustrated a high level of LIF expression in the human uterodomes, which was colocalized with the well-known biochemical markers of exocytosis, including syntaxin-1, 25-kDa synaptosomal protein (SNAP-25) and vesicle-associated membrane protein-2 (VAMP-2). Our morphological and immunocytochemical findings illustrated a secretory function for human uterodomes for the first time. In conclusion, this novel function for uterodomes provides an important clue in detection of their physiological function(s) during the process of the plasma membrane transformation.     

Intraparenchymal pulmonary lymph node: case report and literature review

Summary A case of a 44-year-old woman with a solitary pulmonary coin lesion is presented. Histologic study of this nodule revealed a normal intraparenchymal pulmonary lymph node. A review of the literature discusses the incidence and characteristics of this entity.

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Nud lymphatique intrapulmonaire: revue de la littérature. A propos d'un cas

Résumé L'observation d'un cas de lésion nodulaire du poumon est rapportée chez une femme de 44 ans. L'étude histologique du nodule a révélé un nud lymphatique intrapulmonaire normal. La revue de la littérature apprécie l'incidence et les caractéristiques de cette localisation.

     

Linking DJ-1 to neurodegeneration offers novel insights for understanding the pathogenesis of Parkinson’s disease

Rare monogenic forms of Parkinson's disease (PD) are promoting our understanding of the molecular pathways involved in the common, non-Mendelian forms of the disease. Here, we focus on PARK7, an autosomal recessive form of early-onset parkinsonism caused by mutations in the DJ-1 gene. We first review the genetics of this form and the rapidly expanding knowledge about the structure and biochemical properties of the DJ-1 protein. We also discuss how DJ-1 dysfunction might lead to neurodegeneration, and the implications of this novel piece of information for the pathogenesis of the common PD forms. Although much work remains to be done to clarify the biology of DJ-1, its proposed activity as a molecular chaperone and/or as oxidative sensor appear intriguing in the light of the current theories on the pathogenesis of PD.     

Isolated diffuse hemangiomatosis of the spleen with Kasabach-Merritt-like syndrome

AIMS: Diffuse haemangiomatosis of the spleen is a rare benign vascular condition occurring as a manifestation of systemic angiomatosis or, less commonly, confined to the spleen. It is sometimes accompanied by severe disturbance of blood coagulation. The goal of this study was to characterize an additional case of isolated diffuse haemangiomatosis of the spleen and to determine the histogenesis of this lesion which remains obscure. METHODS AND RESULTS: We describe a case of isolated diffuse haemangiomatosis of the spleen in which histological and immunohistological findings suggested the possibility of a malformative tumour-like lesion. The pathological cavernous vessels were distributed randomly through the red pulp, without continuity with sinuses. The endothelial cells expressed vimentin, factor VIII related antigen and CD34, but not CD8. Some cells lining the sinus lumen expressed CD68, lysozyme and myeloperoxidase. In addition, trabecular veins presented with intimal thickening. These results allow making a diagnosis between diffuse haemangiomatosis and other tumours/tumour-like lesions of the spleen, especially littoral cell angioma, splenoma and peliosis. CONCLUSION: If diffuse haemangiomatosis is usually classified as a benign proliferation of endothelial cells, we suggest that diffuse haemangiomatosis, when confined to the spleen, could be a tumour-like vascular lesion. In this hypothesis, the aetiology may be hamartomatous or malformative as is suspected in arterio-venous haemangioma of the lower extremities. The histogenesis is still questionable and no definitive proof in favour of one or the other hypothesis has been reported.     

Pattern of mtDNA Variation in Three Populations from São Tomé e Príncipe

We have analysed the matrilineal genetic composition of three self‐reported ethnic groups from São Tomé e Príncipe (Gulf of Guinea), an African archipelago whose settlement begun in the late fifteenth century. Sequence data from the hypervariable segments I (HVS‐I) and II (HVS‐II) were obtained for 30 Angolares, 35 Forros and 38 Tongas. The repertory of mtDNA lineages in São Tomé e Príncipe denoted a fully African maternal pool, primarily arisen from a Central/Southwestern substratum. The absence of any lineages of putative European descent means that the European impact at the mitochondrial pool was virtually nil. Angolares showed a clear reduction of mtDNA diversity and a slight genetic differentiation relative to Tongas or Forros, whereas the latter two groups did not present any signs of genetic boundaries between each other. The data obtained here reinforce the depiction of genetic substructuring in São Tomé e Príncipe previously derived from Y‐chromosome STRs. In addition, the crossing of mtDNA and Y‐STR information led to the inference that the female mediated gene flow within the archipelago was less restricted than the male, a pattern that could be framed in the cultural traditions and socio‐historical interactions among the groups.     

Histopathology of tumour associated sarcoid-like stromal reaction in breast cancer

Summary In 5 cases of invasive ductal and lobular carcinoma of the breast multiple epithelioid and giant cell containing granulomas were detected, localized mainly in circumferential regions, but also in the center of the carcinomas. These granulomas were interpreted as sarcoid-like stromal reactions, occurring as sarcoid-like lesions in uni- and bilateral primaries, in a recurrent tumour, and also in axillary lymph nodes. Histopathologically, these granulomas were not quite uniform, some of them corresponding to typical sarcoidosis, others showing marked proliferations of epithelioid or giant cells or containing fibrinoid exudate or necroses. The granulomas were surrounded by dense infiltrates of mononuclear cells. Tuberculosis and mycosis was excluded. There were no hints of generalized sarcoidosis. Pathogenetically, these are reactions in the tumour stroma of varying intensity, and are not caused by necroses of the tumour tissue nor by microbial infections. Such tumour-associated sarcoid-like stroma reactions are interpreted as a T-cell mediated immune response to an antigen expression of the carcinoma acting as the local trigger; in 2 cases they were connected with sarcoid-like lesions of the axillary lymph nodes. Their occurrence in bilateral carcinoma of the breast points to an immunological disposition for this special kind of host-versus-tumour response. The intensity of these changes in a recurrent tumour reflects an immunological hypersensitivity reaction.The pathogenetic and differential diagnostic aspects of epithelioid granulomas of the female breast in chronic granulomatous mastitis, panniculitis, foreign body reaction, rare infections, and in therapeutically induced sarcoidosis are described and discussed.Dedicated to Prof. Dr. K. Lennert, Kiel, in Honour of his 65th Birthday     

Système de télésurveillance sonore pour la détection de situations de détresse

The telemedicine and medical remote monitoring in particular, today represents an effective solution to the health professional shortcomings facing to the increasing older population. In addition to the comfort of being at home, this system decreases the cost of long hospitalization. The proposed system achieves the home medical telesurveillance by means of microphones and medical sensors to detect a distress situation. This system is designed for elderly people at home or for the patient with chronic illness. The experimental apartment is equipped with medical sensors (tensiometer, oxymeter, balance, etc.), infrared position sensors, and acoustic sensors (1 microphone/room). The originality of the system comes from the replacement of the video surveillance with a sound surveillance. The sound analysis system is divided in two stages: firstly, the detection/extraction of the sounds is operated and secondly, a classification of these sounds in known classes takes place. A wavelet-based algorithm with good performance when applied in noisy environments is proposed. The acoustical classification step uses a Gaussian Mixture Models to classify the sounds according to the 7 predefined classes. The detection algorithm allows an equal error rate of 0% for the signal to noise ratio superior or equal to 10 dB and 4% for the 0 dB. The proposed system coupled with a classical medical telesurveillance system will bring extra information needed for the reliability of the global system.