157 research outputs found

    Regulation of Neuronal APL-1 Expression by Cholesterol Starvation

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    Background: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the deposition of b-amyloid plaques composed primarily of the amyloid-b peptide, a cleavage product of amyloid precursor protein (APP). While mutations in APP lead to the development of Familial Alzheimer’s Disease (FAD), sporadic AD has only one clear genetic modifier: the e4 allele of the apolipoprotein E (ApoE) gene. Cholesterol starvation in Caenorhabditis elegans leads to molting and arrest phenotypes similar to loss-of-function mutants of the APP ortholog, apl-1 (amyloid precursor-like protein 1), and lrp-1 (lipoprotein receptor-related protein 1), suggesting a potential interaction between apl-1 and cholesterol metabolism. Methodology/Principal Findings: Previously, we found that RNAi knock-down of apl-1 leads to aldicarb hypersensitivity, indicating a defect in synaptic function. Here we find the same defect is recapitulated during lrp-1 knock-down and by cholesterol starvation. A cholesterol-free diet or loss of lrp-1 directly affects APL-1 levels as both lead to loss of APL-1::GFP fluorescence in neurons. However, loss of cholesterol does not affect global transcription or protein levels as seen by qPCR and Western blot. Conclusions: Our results show that cholesterol and lrp-1 are involved in the regulation of synaptic transmission, similar to apl-1. Both are able to modulate APL-1 protein levels in neurons, however cholesterol changes do not affect global apl-1 transcription or APL-1 protein indicating the changes are specific to neurons. Thus, regulation of synaptic transmission an

    A complex regional intervention to implement advance care planning in one town's nursing homes: Protocol of a controlled inter-regional study

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    <p>Abstract</p> <p>Background</p> <p>Advance Care Planning (ACP) is an emerging strategy to ensure that well-reflected, meaningful and clearly documented treatment preferences are available and respected when critical decisions about life-sustaining treatment need to be made for patients unable to consent. In Germany, recent legislation confirms that advance directives (AD) have to be followed if they apply to the medical situation, but implementation of ACP has not yet been described.</p> <p>Methods/Design</p> <p>In a longitudinal controlled study, we compare 1 intervention region (4 nursing homes [n/hs], altogether 421 residents) with 2 control regions (10 n/hs, altogether 985 residents). Inclusion went from 01.02.09 to 30.06.09, observation lasted until 30.06.10. Primary endpoint is the prevalence of ADs at follow-up, 17 (12) months after the first (last) possible inclusion. Secondary endpoints compare relevance and validity of ADs, process quality, the rate of life-sustaining interventions and, in deceased residents, location of death and intensity of treatment before death. The regional multifaceted intervention on the basis of the US program Respecting Choices<sup>® </sup>comprises training of n/h staff as facilitators, training of General Practitioners, education of hospital and ambulance staff, and development of eligible tools, including Physician Orders for Life-Sustaining Treatment in case of Emergency (POLST-E).</p> <p><it>Participation data: </it>Of 1406 residents reported to live in the 14 n/hs plus an estimated turnover of 176 residents until the last possible inclusion date, 645 (41%) were willing to participate. Response rates were 38% in the intervention region and 42% in the control region. Non-responder analysis shows an equal distribution of sex and age but a bias towards dependency on nursing care in the responder group. <it>Outcome analysis </it>of this study will become available in the course of 2011.</p> <p>Discussion</p> <p>Implementing an ACP program for the n/hs and related health care providers of a region requires a complex community intervention with the effect of nothing less than a cultural shift in this health care sector. This study is to our knowledge the first to develop a strategy for regional implementation of ACP, and to evaluate its feasibility in a controlled design.</p> <p>Trial Registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN99887420">ISRCTN99887420</a></p

    Human monkeypox virus infection in women and non-binary individuals during the 2022 outbreaks: a global case series.

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    BACKGROUND: Between May and November, 2022, global outbreaks of human monkeypox virus infection have been reported in more than 78 000 people worldwide, predominantly in men who have sex with men. We describe the epidemiological and clinical characteristics of monkeypox virus infection in cisgender (cis) and transgender (trans) women and non-binary individuals assigned female sex at birth to improve identification and understanding of risk factors. METHODS: International collaborators in geographical locations with high numbers of diagnoses of monkeypox virus infection were approached and invited to contribute data on women and non-binary individuals with confirmed monkeypox virus infection. Contributing centres completed deidentified structured case-report spreadsheets, adapted and developed by participating clinicians, to include variables of interest relevant to women and non-binary individuals assigned female at birth. We describe the epidemiology and clinical course observed in the reported infections. FINDINGS: Collaborators reported data for a total of 136 individuals with monkeypox virus infection who presented between May 11 and Oct 4, 2022, across 15 countries. Overall median age was 34 years (IQR 28-40; range 19-84). The cohort comprised 62 trans women, 69 cis women, and five non-binary individuals (who were, because of small numbers, grouped with cis women to form a category of people assigned female at birth for the purpose of comparison). 121 (89%) of 136 individuals reported sex with men. 37 (27%) of all individuals were living with HIV, with a higher proportion among trans women (31 [50%] of 62) than among cis women and non-binary individuals (six [8%] of 74). Sexual transmission was suspected in 55 (89%) trans women (with the remainder having an unknown route of transmission) and 45 (61%) cis women and non-binary individuals; non-sexual routes of transmission (including household and occupational exposures) were reported only in cis women and non-binary individuals. 25 (34%) of 74 cis women and non-binary individuals submitted to the case series were initially misdiagnosed. Overall, among individuals with available data, rash was described in 124 (93%) of 134 individuals and described as anogenital in 95 (74%) of 129 and as vesiculopustular in 105 (87%) of 121. Median number of lesions was ten (IQR 5-24; range 1-200). Mucosal lesions involving the vagina, anus, or oropharynx or eye occurred in 65 (55%) of 119 individuals with available data. Vaginal and anal sex were associated with lesions at those sites. Monkeypox virus DNA was detected by PCR from vaginal swab samples in all 14 samples tested. 17 (13%) individuals were hospitalised, predominantly for bacterial superinfection of lesions and pain management. 33 (24%) individuals were treated with tecovirimat and six (4%) received post-exposure vaccinations. No deaths were reported. INTERPRETATION: The clinical features of monkeypox in women and non-binary individuals were similar to those described in men, including the presence of anal and genital lesions with prominent mucosal involvement. Anatomically, anogenital lesions were reflective of sexual practices: vulvovaginal lesions predominated in cis women and non-binary individuals and anorectal features predominated in trans women. The prevalence of HIV co-infection in the cohort was high. FUNDING: None

    A Novel Xenogeneic Co-Culture System to Examine Neuronal Differentiation Capability of Various Adult Human Stem Cells

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    Background: Targeted differentiation of stem cells is mainly achieved by the sequential administration of defined growth factors and cytokines, although these approaches are quite artificial, cost-intensive and time-consuming. We now present a simple xenogeneic rat brain co-culture system which supports neuronal differentiation of adult human stem cells under more in vivo-like conditions. Methods and Findings: This system was applied to well-characterized stem cell populations isolated from human skin, parotid gland and pancreas. In addition to general multi-lineage differentiation potential, these cells tend to differentiate spontaneously into neuronal cell types in vitro and are thus ideal candidates for the introduced co-culture system. Consequently, after two days of co-culture up to 12% of the cells showed neuronal morphology and expressed corresponding markers on the mRNA and protein level. Additionally, growth factors with the ability to induce neuronal different iation in stem cells could be found in the media supernatants of the co-cultures. Conclusions: The co-culture system described here is suitable for testing neuronal differentiation capability of numerous types of stem cells. Especially in the case of human cells, it may be of clinical relevance for future cell-based therapeutic applications

    The Fate of Porous Hydroxyapatite Granules Used in Facial Skeletal Augmentation

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    Facial appearance is largely determined by the morphology of the underlying skeleton. Hydroxyapatite is one of several materials available to enhance projection of the facial skeleton. This study evaluated the long-term maintenance of augmented bony projection when porous hydroxyapatite granules are used on the facial skeleton. Ten female patients aged 28–58 years were studied following aesthetic augmentation of the facial skeleton at 24 sites using porous hydroxyapatite granules. Postoperative CT scans at 3 months served as the baseline measurement and compared with scans taken at 1 and 2 years, with the thickness of the hydroxyapatite measured in axial and coronal planes. Thickness of original bone plus overlay of hydroxyapatite, thickness of the overlying soft tissue, and the overall projection (bone plus soft tissue) were recorded. It was found that 99.7% of the hydroxyapatite was maintained at 2 years, with no statistical difference (t test) from the baseline measurement. The overall projection (bony and soft tissue) was maintained as there was no evidence of native bone resorption or soft tissue atrophy. Radiographic results confirmed that the use of porous hydroxyapatite granules for enhancement of the facial skeleton is not only a predictable procedure, but maintains full bony projection at 2 years

    Nogo-A Expression in the Brain of Mice with Cerebral Malaria

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    Cerebral malaria (CM) is associated with a high rate of transient or persistent neurological sequelae. Nogo-A, a protein that is highly expressed in the endoplasmic reticulum (ER) of the mammalian central nervous system (CNS), is involved in neuronal regeneration and synaptic plasticity in the injured CNS. The current study investigates the role of Nogo-A in the course of experimental CM. C57BL/6J mice were infected with Plasmodium berghei ANKA blood stages. Brain homogenates of mice with different clinical severity levels of CM, infected animals without CM and control animals were analyzed for Nogo-A up-regulation by Western blotting and immunohistochemistry. Brain regions with Nogo-A upregulation were evaluated by transmission electron microscopy. Densitometric analysis of Western blots yielded a statistically significant upregulation of Nogo-A in mice showing moderate to severe CM. The number of neurons and oligodendrocytes positive for Nogo-A did not differ significantly between the studied groups. However, mice with severe CM showed a significantly higher number of cells with intense Nogo-A staining in the brain stem. In this region ultrastructural alterations of the ER were regularly observed. Nogo-A is upregulated during the early course of experimental CM. In the brain stem of severely affected animals increased Nogo-A expression and ultrastructural changes of the ER were observed. These data indicate a role of Nogo-A in neuronal stress response during experimental CM

    Exosomes Communicate Protective Messages during Oxidative Stress; Possible Role of Exosomal Shuttle RNA

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    BACKGROUND: Exosomes are small extracellular nanovesicles of endocytic origin that mediate different signals between cells, by surface interactions and by shuttling functional RNA from one cell to another. Exosomes are released by many cells including mast cells, dendritic cells, macrophages, epithelial cells and tumour cells. Exosomes differ compared to their donor cells, not only in size, but also in their RNA, protein and lipid composition. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we show that exosomes, released by mouse mast cells exposed to oxidative stress, differ in their mRNA content. Also, we show that these exosomes can influence the response of other cells to oxidative stress by providing recipient cells with a resistance against oxidative stress, observed as an attenuated loss of cell viability. Furthermore, Affymetrix microarray analysis revealed that the exosomal mRNA content not only differs between exosomes and donor cells, but also between exosomes derived from cells grown under different conditions; oxidative stress and normal conditions. Finally, we also show that exposure to UV-light affects the biological functions associated with exosomes released under oxidative stress. CONCLUSIONS/SIGNIFICANCE: These results argue that the exosomal shuttle of RNA is involved in cell-to-cell communication, by influencing the response of recipient cells to an external stress stimulus

    C9ORF72 interaction with cofilin modulates actin dynamics in motor neurons.

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    Intronic hexanucleotide expansions in C9ORF72 are common in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, but it is unknown whether loss of function, toxicity by the expanded RNA or dipeptides from non-ATG-initiated translation are responsible for the pathophysiology. We determined the interactome of C9ORF72 in motor neurons and found that C9ORF72 was present in a complex with cofilin and other actin binding proteins. Phosphorylation of cofilin was enhanced in C9ORF72-depleted motor neurons, in patient-derived lymphoblastoid cells, induced pluripotent stem cell-derived motor neurons and post-mortem brain samples from ALS patients. C9ORF72 modulates the activity of the small GTPases Arf6 and Rac1, resulting in enhanced activity of LIM-kinases 1 and 2 (LIMK1/2). This results in reduced axonal actin dynamics in C9ORF72-depleted motor neurons. Dominant negative Arf6 rescues this defect, suggesting that C9ORF72 acts as a modulator of small GTPases in a pathway that regulates axonal actin dynamics

    Could lymphatic mapping and sentinel node biopsy provide oncological providence for local resectional techniques for colon cancer? A review of the literature

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    <p>Abstract</p> <p>Background</p> <p>Endoscopic resectional techniques for colon cancer are undermined by their inability to determine lymph node status. This limits their application to only those lesions at the most minimal risk of lymphatic dissemination whereas their technical capacity could allow intraluminal or even transluminal address of larger lesions. Sentinel node biopsy may theoretically address this breach although the variability of its reported results for this disease is worrisome.</p> <p>Methods</p> <p>Medline, EMBASE and Cochrane databases were interrogated back to 1999 to identify all publications concerning lymphatic mapping for colon cancer with reference cross-checking for completeness. All reports were examined from the perspective of in vivo technique accuracy selectively in early stage disease (i.e. lesions potentially within the technical capacity of endoscopic resection).</p> <p>Results</p> <p>Fifty-two studies detailing the experiences of 3390 patients were identified. Considerable variation in patient characteristics as well as in surgical and histological quality assurances were however evident among the studies identified. In addition, considerable contamination of the studies by inclusion of rectal cancer without subgroup separation was frequent. Indeed such is the heterogeneity of the publications to date, formal meta-analysis to pool patient cohorts in order to definitively ascertain technique accuracy in those with T1 and/or T2 cancer is not possible. Although lymphatic mapping in early stage neoplasia alone has rarely been specifically studied, those studies that included examination of false negative rates identified high T3/4 patient proportions and larger tumor size as being important confounders. Under selected circumstances however the technique seems to perform sufficiently reliably to allow it prompt consideration of its use to tailor operative extent.</p> <p>Conclusion</p> <p>The specific question of whether sentinel node biopsy can augment the oncological propriety for endoscopic resective techniques (including Natural Orifice Transluminal Endoscopic Surgery [NOTES]) cannot be definitively answered at present. Study heterogeneity may account for the variability evident in the results from different centers. Enhanced capacity (perhaps to the level necessary to consider selective avoidance of en bloc mesenteric resection) by its confinement to only early stage disease is plausible although not proven. Specific study of the technique in early stage tumors is clearly essential before proffering this approach.</p
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