Replicative senescence of human dermal fibroblasts affects structural and functional aspects of the Golgi apparatus

It is well recognized that the world population is ageing rapidly. Therefore, it is important to understand ageing processes at the cellular and molecular levels to predict the onset of age‐related diseases and prevent them. Recent research has focused on the identification of ageing biomarkers, including those associated with the properties of the Golgi apparatus. In this context, Golgi‐mediated glycosylation of proteins has been well characterized. Additionally, other studies show that the secretion of many compounds, including pro‐inflammatory cytokines and extracellular matrix–degrading enzymes, is modified during ageing, resulting in physical and functional skin degradation. Since the Golgi apparatus is a central organelle of the secretory pathway, we investigated its structural organization in senescent primary human dermal fibroblasts using confocal and electron microscopy. In addition, we monitored the expression of Golgi‐related genes in the same cells. Our data showed a marked alteration in the Golgi morphology during replicative senescence. In contrast to its small and compact structure in non‐senescent cells, the Golgi apparatus exhibited a large and expanded morphology in senescent fibroblasts. Our data also demonstrated that the expression of many genes related to Golgi structural integrity and function was significantly modified in senescent cells, suggesting a relationship between Golgi apparatus function and ageing.     

Epileptic electroencephalographic abnormalities and developmental dysphasias: a study of 32 patients.

The relationships between severe developmental dysphasias and epilepsy were analysed in 32 patients with congenital dysphasias. The mean age was 8 years 2 months; 19 of 32 had never had seizures; 9 had had occasional seizures; 4 were epileptic. Twenty-two of 32 had normal repeated standard EEGs, but 10 (2 of which never had seizures) showed epileptic interictal discharges. During prolonged EEG after sleep deprivation, epileptic abnormalities were observed in 13 of the 32 cases (4 of which never had seizures). The overall night sleep recordings showed epileptic abnormalities in 30 of the 32 cases (17 of which had never had seizures). The epileptic interictal abnormalities varied considerably in intensity and aspect in the same patient from one examination to another. Developmentally aphasic children show a higher incidence of abnormal EEG than expected, particularly during overall night recordings. In most cases, the physiopathology of the language disturbance might be identical to that in Landau-Kleffner syndrome.     

Auto-protective redox buffering systems in stimulated macrophages

Background

Macrophages, upon encounter with micro-organisms or stimulated by cytokines, produce various effector molecules aimed at destroying the foreign agents and protecting the organism. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are front line molecules exerting strong cytotoxic activities against micro-organisms and many cells, including macrophages themselves. Using cells of the murine macrophage cell line (RAW 264.7) stimulated in vitro with lipopolysaccharide (LPS) and/or interferon (IFN-γ), which induce strong endogenous NO production, we examined by which mechanisms a fraction of activated macrophages protect themselves from nitrosative stress and manage to escape destruction?

Results

We observed that survivors (10–50% depending on the experiments) had acquired a resistant phenotype being capable to survive when further exposed in vitro to an apoptosis inducing dose of the NO donor compound DETA-NO. These cells expressed an increased steady-state levels of Mn SOD, CuZn SOD and catalase mRNA (130–200%), together with an increased activity of the corresponding enzymes. Intracellular concentration of glutathione was also increased (× 3.5 fold at 6 hours, still maintained × 5.2 fold at 48 hours). Neither mRNA for glutathione peroxydase, γ-glutamylcysteine synthase and glutathione reductase, nor thioredoxine and thioredoxine reductase, were significantly modified. Additional experiments in which RAW 264.7 cells were stimulated with LPS and/or IFN-γ in the presence of relatively specific inhibitors of both Mn and Cu/Zn SOD, aminotriazol (ATZ) catalase inhibitor and buthionine sulfoximine (BSO) glutathione inhibitor, showed that inhibiting LPS-induced up-regulation of intracellular redox buffering systems also prevented acquisition of the resistant phenotype.

Conclusions

Our data suggest a direct causal relationship between survival of a fraction of macrophages and a up-regulation of key sets of auto-protective intracellular redox buffering systems, occurring simultaneously with modulation of expression of apoptotic molecules of the Bcl₂-Bcl-_XL/Bax-Bad family.     

Glucocorticoids down-regulate dendritic cell function in vitro and in vivo

Exogenous glucocorticoid hormones are widely used as therapeutical agents, whereas endogenous glucocorticoids may act as physiological immunosuppressants involved in the control of immune and inflammatory responses. The optimal activation of T lymphocytes requires two distinct signals: the major histocompatibility complex-restricted presentation of the antigen and an additional co-stimulatory signal provided by the antigen-presenting cells. There is ample evidence that, among the cells able to present the antigen, the dendritic cells (DC) have the unique property to activate antigen-specific, naive T cells in vitro and in vivo, and are therefore required for the induction of primary immune responses. In this work, we tested whether glucocorticoids affected the capacity of DC to sensitize naive T cells. Our data show that, in vitro, the steroid hormone analog dexamethasone (Dex) affects the viability of DC, selectively downregulates the expression of co-stimulatory molecules on viable DC, and strongly reduces their immunostimulatory properties. In vivo, a single injection of Dex results in impaired antigen presenting function, a finding which correlates with reduced numbers of splenic DC. These results show that glucocorticoids regulate DC maturation and immune function in vitro and in vivo and suggest that this mechanism may play a role in preventing overstimulation of the immune system.     

Prenatal detection of a 17p11.2 duplication resulting from a rare recombination event and novel PCR-based strategy for molecular identification of Charcot-Marie-Tooth disease type 1A

Charcot-Marie-Tooth disease, type 1A (CMT1A) is caused in most cases by a 1.5 Mb duplication on chromosome 17p11.2 arising after unequal crossing-over between repeated sequences called CMT1A-REPs, flanking the 1.5 Mb unit. A 3.2 kb recombination hot spot has been defined, resulting in a junction fragment between EcoRI (distal CMT1A-REP) and SacI (proximal CMT1A-REP). This was further reduced to a 1.7kb EcoRI-NsiI fragment, and recently to a 731 bp hot spot region within this fragment. We describe the CMT1A-REPs-based PCR method used to identify CMT1A duplications and report on a family case in which a 29-year-old pregnant woman requested prenatal diagnosis for two successive pregnancies because her husband was affected with CMT1A. Our method enabled us to characterise the duplication in both foetuses and demonstrate that it arose from a rare recombination event taking place outside the 1.7 kb region. Since our approach is simple and enables the entire set of duplications occurring after recombination in the enlarged 3.2kb region including the hot spot to be detected, we suggest it might be considered for use in primary screening for pre- and postnatal diagnosis of CMT1A.     

A review of burn symptoms and potential novel neural targets for non-invasive brain stimulation for treatment of burn sequelae

Burn survivors experience myriad associated symptoms such as pain, pruritus, fatigue, impaired motor strength, post-traumatic stress, depression, anxiety, and sleep disturbance. Many of these symptoms are common and remain chronic, despite current standard of care. One potential novel intervention to target these post burn symptoms is transcranial direct current stimulation (tDCS). tDCS is a non-invasive brain stimulation (NIBS) technique that modulates neural excitability of a specific target or neural network. The aim of this work is to review the neural circuits of the aforementioned clinical sequelae associated with burn injuries and to provide a scientific rationale for specific NIBS targets that can potentially treat these conditions. We ran a systematic review, following the PRISMA statement, of tDCS effects on burn symptoms. Only three studies matched our criteria. One was a feasibility study assessing cortical plasticity in chronic neuropathic pain following burn injury, one looked at the effects of tDCS to reduce pain anxiety during burn wound care, and one assessed the effects of tDCS to manage pain and pruritus in burn survivors. Current literature on NIBS in burn remains limited, only a few trials have been conducted. Based on our review and results in other populations suffering from similar symptoms as patients with burn injuries, three main areas were selected: the prefrontal region, the parietal area and the motor cortex. Based on the importance of the prefrontal cortex in the emotional component of pain and its implication in various psychosocial symptoms, targeting this region may represent the most promising target. Our review of the neural circuitry involved in post burn symptoms and suggested targeted areas for stimulation provide a spring board for future study initiatives.     

Reproducibility and diagnostic value of a new method using ratios to diagnose anterior atlanto-axial subluxation on plain radiographs

ObjectivesMeasures on conventional radiography are used to detect, especially in rheumatoid arthritis, upper cervical spine instabilities (CSIs) with the anterior and posterior atlanto-dental intervals (AADI and PADI) measurements. Our objective was to evaluate the diagnostic performance and reliability of AADIs and PADIs extrapolated based on ratios in assessing anterior atlanto-axial subluxation (aAAS) when plain radiographs do not allow the measures.MethodsRadiographies of 119 patients were randomly selected. Two blinded observers performed two measurements of the odontoid sagittal diameter (O), axis body base sagittal diameter (C2), AADI, PADI, Clark station and Ranawat index, and the AADI/O, AADI/C2, PADI/O and PADI/C2 ratios were calculated. The diagnostic value of AADI and PADI extrapolated from the AADI/O, AADI/C2, PADI/O and PADI/C2 ratios was evaluated using ROC curves, with AADI > 2.9 mm used as the gold standard.ResultsAmong the 119 patients, 12 patients had aAAS (AADI > 2.9 mm), 6 of them had severe aAAS (AADI > 8.9 mm and/or a PADI < 14 mm), and 6 patients had vertical AAS (Clarks station = 2 or 3 and/or Ranawat index < 13 mm). The AADI extrapolated from the AADI/O and AADI/C2 ratios has excellent intra- and inter-observer reproducibility. The diagnostic value of the extrapolated AADI was high for aAAS (sensitivity 92%; specificity of 100%) and severe aAAS (sensitivity75%; specificity 100%). The diagnostic value of the extrapolated PADI was good but lower than the diagnostic value of the extrapolated AADI.ConclusionExtrapolated AADI can be used instead AADI to detect aAAS and severe aAAS.     

Current immunoassays and detection of antibodies elicited by Omicron SARS-CoV-2 infection

The present study aimed to determine whether current commercial immunoassays are adequate for detecting anti-Omicron antibodies. We analyzed the anti-SARS-CoV-2 antibody response of 23 unvaccinated individuals 1–2 months after an Omicron infection. All blood samples were tested with a live virus neutralization assay using a clinical Omicron BA.1 strain and four commercial SARS-CoV-2 immunoassays. We assessed three anti-Spike immunoassays (SARS-CoV-2 IgG II Quant [Abbott S], Wantaï anti-SARS-CoV-2 antibody ELISA [Wantaï], Elecsys Anti-SARS-CoV-2 S assay [Roche]) and one anti-Nucleocapsid immunoassay (Abbott SARS-CoV-2 IgG assay [Abbott N]). Omicron neutralizing antibodies were detected in all samples with the live virus neutralization assay. The detection rate of the Abbott S, Wantai, Roche, and Abbott N immunoassays were 65.2%, 69.6%, 86.9%, and 91.3%, respectively. The sensitivities of Abbott S and Wantai immunoassays were significantly lower than that of the live virus neutralization assay (p = 0.004, p = 0.009; Fisher's exact test). Antibody concentrations obtained with anti-S immunoassays were correlated with Omicron neutralizing antibody concentrations. These data provide clinical evidence of the loss of performance of some commercial immunoassays to detect antibodies elicited by Omicron infections. It highlights the need to optimize these assays by adapting antigens to the circulating SARS-CoV-2 strains.     

Can Flemish women in semi-rural areas be motivated to attend organized breast cancer screening?

BACKGROUND: The implementation of organized breast cancer screening in Flanders was prepared by means of pilot projects within a multicenter study. In the semi-rural district of Kontich (Province of Antwerp, Flanders) a pilot project was performed using a mobile screening unit. Compared to international standards, the attendance rate for this pilot project (i.e. 34%) was low. Non-organized screening, which already exists in Flanders, at least partly explains this low attendance rate for the organized screening. The main purpose of our study was to investigate the experience of the pilot target group with respect to the organized breast cancer screening in the district of Kontich, in order to maximize the conditions for a high attendance rate in the organized breast cancer screening programme throughout Flanders. METHODS: With a random numbers procedure, performed by the computer, 500 women were selected among those who were invited to the first screening round of the breast cancer screening programme in the district of Kontich (n = 6,897). These 500 randomly selected women were asked to cooperate with a face-to-face interview. The questionnaire used dealt with the different aspects of the organized mammographic screening which were expected to influence the decision to attend. RESULTS: There were 348 women who responded to the questionnaire (69.6%): 138 of them were attenders and 210 were non-attenders at the organized breast cancer screening. Attenders and non-attenders at the organized breast cancer screening in the district of Kontich had different views about various aspects of the screening programme. The percentages of those who thought that an item was important or very important to them, were for the 138 attenders and the 210 non-attenders respectively: "to receive a personal invitation letter": 90.6 vs. 48.1% (p < 0.05); "a preliminary visit to the GP": 9.4 vs. 34.3% (p < 0.05); "possibility of examination outside business hours": 15.9 vs. 30.0% (p < 0.05). CONCLUSIONS: Although the putting into action of a mobile unit in the semi-rural area of the district of Kontich was productive, the attendance rate was still too low compared to international standards. To increase the attendance rate, the following interventions should be considered: devising the personal invitation letter in a more attractive way, activating and stimulating the important motivational role of the GP in persuading women to attend the organized screening programme and offering the invited population the possibility to have a mammographic examination performed outside business hours. Appropriate measures are being explored.     

Proton magnetic resonance spectroscopy of the medial prefrontal cortex in patients with deficit schizophrenia: preliminary report

OBJECTIVE: Proton magnetic resonance spectroscopy (1H-MRS) was used to study medial prefrontal metabolic impairments in schizophrenic patients with the deficit syndrome. METHOD: The subjects were 22 schizophrenic patients categorized as deficit (N=5) or nondeficit (N=17) and 21 healthy subjects. (1)H-MRS was performed for the right and the left medial prefrontal cortex. RESULTS: The patients with the deficit syndrome had significantly lower ratios of N-acetylaspartate to creatine plus phosphocreatine than did the healthy subjects or nondeficit patients. CONCLUSIONS: As N-acetylaspartate levels could reflect neuronal density and/or viability, this finding suggests a neuronal loss in the medial prefrontal cortex of deficit patients.