Oxidation of ultralene and paraffin due to radiation damage after exposure to soft X-rays probed by FTIR microspectroscopy and X-ray fluorescence.

Radiation damage upon soft X-ray exposure is an important issue to be considered in soft X-ray microscopy. The work presented here is part of a more extended study on the topic and focuses on the effects of soft X-rays on paraffin, a common embedding medium for soft-tissues, and on ultralene and Si3N4 windows as sample supports. Our studies suggest that the sample environment indeed plays an important role in the radiation damage process and therefore should be carefully taken into account for the analysis and interpretation of new data. The radiation damage effects were followed over time using a combination of Fourier transform infrared (FTIR) microspectroscopy and X-ray fluorescence (XRF), and it was demonstrated that, for higher doses, an oxidation of both embedding medium and ultralene substrate takes place after the irradiated sample is exposed to air. This oxidation is reflected in a clear increase of C=O and O-H infrared bands and on the XRF oxygen maps, correlated with a decrease of the aliphatic infrared signal. The results also show that the oxidation process may affect quantitative evaluation of light element concentrations.

A label-free immunoassay for Flavivirus detection by the Reflective Phantom Interface technology.

Flaviviruses are widespread and cause clinically relevant arboviral diseases that impact locally and as imported travel-related infections. Direct detection of viraemia is limited, being typically undetectable at onset of symptoms. Therefore, diagnosis is primarily based on serology, which is complicated by high cross-reactivity across different species. The overlapping geographical distribution of the vectors in areas with a weak healthcare system, the increase of international travel and the similarity of symptoms highlight the need for rapid and reliable multi-parametric diagnostic tests in point-of-care formats. To this end we developed a bi-parametric serological microarray using recombinant NS1 proteins from Tick-borne encephalitis virus and West Nile virus coupled to a low-cost, label-free detection device based on the Reflective Phantom Interface (RPI) principle. Specific sequential detection of antibodies in solution demonstrates the feasibility of the approach for the surveillance and diagnosis of Flaviviruses.

Topoisomerase IIß mediates the resistance of glioblastoma stem cells to replication stress-inducing drugs.

BACKGROUND: Glioblastoma stem cells (GSC) have been extensively recognized as a plausible cause of glioblastoma resistance to therapy and recurrence resulting in high glioblastoma mortality. Abnormalities in the DNA repair pathways might be responsible for the inability of the currently used chemotherapeutics to eliminate the (GSC) subpopulation. METHODS: In this work, we compared the expression of sixty DNA repair related genes between primary glioblastoma cell cultures and the glioblastoma enriched stem cell primary cultures. MTT test was used to analyze the effect of selected drugs and immunofluorescence to evaluate the load of DNA damage. RESULTS: We found several differentially expressed genes and we identified topoisomerase IIß (Top2ß) as the gene with highest up-regulation in GSC. Also among the tested cell lines the expression of Top2ß was the highest in NCH421k cells, a well-characterized glioblastoma cell line with all the stemness characteristics. On the other hand, Top2ß expression markedly decreased upon the induction of differentiation by all trans-retinoic acid. Depletion of Top2ß increased the sensitivity of NCH421k cells to replication stress inducing drugs, such as cisplatin, methyl-methanesulfonate, hydrogen peroxide, and temozolomide. Consistently, we found an increased load of DNA damage and increased Chk1 activation upon Top2ß depletion in NCH421k cells. CONCLUSION: We suggest that Top2ß may represent a new target for gene therapy in glioblastoma. In addition, the other genes that we found to be up-regulated in GSC versus glioblastoma primary cells should be further investigated as glioblastoma theranostics.

Expression of the Endocannabinoid Receptor 1 in Human Stroke: An Autoptic Study.

OBJECTIVE: Stroke is one of the leading causes of disability and death in the world. The endocannabinoid (eCB) system is upregulated in several neurological diseases including stroke. A previous animal study demonstrated an increased expression of the endocannabinoid receptor 1 (CB1R) in the penumbra area surrounding the ischemic core, suggesting a crucial role in inflammation/reperfusion after stroke. Regarding the localization of CB1/CB2 receptors, animal studies showed that cortical neurons, activated microglia, and astroglia are involved. Our aim was to evaluate the cerebral expression of CB1R in the ischemic brain areas of 9 patients who died due to acute cerebral infarction in the middle cerebral artery territory. METHODS: The cerebral autoptic tissue was collected within 48 hours since death. Ischemic and contralateral normal-appearing areas were identified. After tissue preprocessing, 4-µm-thick cerebral sections were incubated with the primary CB1R antibodies (Cayman Chemical Company, Ann Arbor, MI). Thereafter, all cerebral sections were hematoxylin treated. In each section, the total cell number and CB1R-positive cells were counted and the CB1R-positive cell count ratio was calculated. For statistical analysis, Student's t-test was used. RESULTS: In normal tissue, CB1R-positive neurons were the majority; a few non-neuronal cells expressed CB1R. In the ischemic areas, a few neurons were detectable. A significant increase in total CB1R staining was found in the ischemic regions compared to contralateral areas. CONCLUSIONS: We found an increase in CB1R expression in the ischemic region (neuronal and non-neuronal cell staining), suggesting the inflammatory reaction to the ischemic insult. Whether such response might mediate neuroprotective actions or excitotoxicity-related detrimental effects is still unclear.

The human RECQ1 helicase is highly expressed in glioblastoma and plays an important role in tumor cell proliferation.

BACKGROUND: RecQ helicases play an essential role in the maintenance of genome stability. In humans, loss of RecQ helicase function is linked with predisposition to cancer and/or premature ageing. Current data show that the specific depletion of the human RECQ1 helicase leads to mitotic catastrophe in cancer cells and inhibition of tumor growth in mice. RESULTS: Here, we show that RECQ1 is highly expressed in various types of solid tumors. However, only in the case of brain gliomas, the high expression of RECQ1 in glioblastoma tissues is paralleled by a lower expression in the control samples due to the poor expression of RECQ1 in non-dividing tissues. This conclusion is validated by immunohistochemical analysis of a tissue microarray containing 63 primary glioblastomas and 19 perilesional tissue samples, as control. We also show that acute depletion of RECQ1 by RNAi results in a significant reduction of cellular proliferation, perturbation of S-phase progression, and spontaneous γ-H2AX foci formation in T98G and U-87 glioblastoma cells. Moreover, RECQ1 depleted T98G and U-87 cells are hypersensitive to HU or temozolomide treatment. CONCLUSIONS: Collectively, these results indicate that RECQ1 has a unique and important role in the maintenance of genome integrity. Our results also suggest that RECQ1 might represent a new suitable target for anti cancer therapies aimed to arrest cell proliferation in brain gliomas.

Comparative specificity and sensitivity of NS1-based serological assays for the detection of flavivirus immune response.

Flaviviruses are relevant animal and human pathogens of increasing importance worldwide. The similarities of the initial clinical symptoms and the serological cross-reactivity of viral structural antigens make a laboratory diagnosis of flavivirus infection problematic. The main aim of the present study was the comparative specificity and sensitivity analysis of the non-structural protein NS1 as an antigen to detect flavivirus antibodies in sera from exposed individuals. A strategy for the purification of native recombinant non-structural protein 1 of representative flaviviruses including tick-borne encephalitis, West Nile, Zika and dengue virus was developed. The immunological properties of the purified antigens were analyzed using sera of immunized mice and of infected individuals in comparison with standard commercial assays. Recombinant NS1 protein was confirmed as a valuable option for the detection of flavivirus antibodies with reduced cross-reactivity and high sensitivity offering additional advantages for the detection of vaccine breakthrough cases.

Viral priming of cell intrinsic innate antiviral signaling by the unfolded protein response.

The innate response to a pathogen is critical in determining the outcome of the infection. However, the interplay of different cellular responses that are activated following viral infection and their contribution to innate antiviral signalling has not been clearly established. This work shows that flaviviruses, including Dengue, Zika, West Nile and Tick-borne encephalitis viruses, activate the unfolded protein response before transcription of interferon regulatory factor 3 induced genes. Infection in conditions of unfolded protein response priming leads to early activation of innate antiviral responses and cell intrinsic inhibition of viral replication, which is interferon regulatory factor 3 dependent. These results demonstrate that the unfolded protein response is not only a physiological reaction of the cell to viral infection, but also synergizes with pattern recognition sensing to mount a potent antiviral response.

Effect of the laser beam on implant site preparation: a preliminary pilot study.

The aim of this preliminary study is to histologically evaluate the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser on soft and hard tissues during implant bed preparation, in comparison with bur and cutter in order to observe the following aspects: (i) the shape of the cavity, (ii) the presence of debris, and (iii) structural modification of the cell architecture. Bone temperature changes during the preparation of the implant bed were also measured in order to evaluate thermal damage on soft and hard tissues. Er:YAG laser, Fotona X-Runner scanner and circular cutter of 5 mm diameter were compared using an in vitro model. Implant bed preparations were performed in bovine rib bone (hard tissue) and tongue muscle (soft tissue) tissues. Results of the study show that in all bur samples were present more debris and more blood cells than in laser samples, which, according to the rules of healing processes, can be a negative factor for the osseointegration process. Regarding the thermal effects on soft tissue, they were present when using MAX mode, but absent when using quantum square pulse (QSP) mode. A preliminary conclusion emphasizes the use of laser to prepare the implant site without debris formation. Nowadays, is not still present a laser device that can overtake the technical limitations of the laser scanner (i.e., deepness control and scanner movement during the preparation of the holes, etc.).

Dynamic quadripolar radiofrequency treatment of vaginal laxity/menopausal vulvo-vaginal atrophy: 12-month efficacy and safety.

BACKGROUND: Twelve-month extension of a previous spontaneous exploratory study investigating safety and efficacy of a new low-energy dynamic quadripolar radiofrequency (DQRF) device in: A) premenopausal women with symptoms of vaginal laxity, with special reference to dysuria, urinary incontinence and unsatisfactory sexual life (vaginal laxity arm of the study); B) postmenopausal women with vulvovaginal atrophy/genitourinary syndrome of menopause (VVA/GSM) and VVA/GSM-related symptoms (VVA/GSM arm of the study). DQRF treatment schedule in both study arms: 4 to 6 procedures of 15 to 20 min every 14 days (vaginal laxity, range 12-17 days; VVA/GSM, range 13-16). Operative temperatures in vaginal target tissues during procedure: vaginal laxity, 42 °C (range 40-43 °C); VVA/GSM, 40 °C (range 40-42 °C). METHODS: In the vaginal laxity arm of the study, 25 women with subjective sensation of vaginal introital laxity (very to slightly loose). Assessment of urinary incontinence, satisfaction with sexual relationship and contribution of pelvic organ prolapse: Vaginal Laxity Questionnaire (VLQ, Italian certified translation) and short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12, Italian certified translation). Further evaluation of sexual gratification: Sexual Satisfaction Questionnaire (SSQ). In the VVA/GSM arm of the study, 32 women with objective evidence of VVA and vaginal dryness and/or dyspareunia as most bothersome symptoms. Assessment of VVA/GSM symptoms and overall satisfaction with sexual life: specifically designed 10-cm visual analogue scales. RESULTS: All 4 to 6 planned DQRF sessions were well tolerated in both the vaginal laxity and VVA/GSM arms of the study, with no troubling pain, thermal injury or other immediate adverse effects during all the procedures. All screened women completed the planned DQRF treatment sessions in both arms of the extension study. There was no participant attrition with only a few occasionally missing visits over the 12-month follow-up period. Improvements were rapid in self-perception of introital looseness and related symptoms like dysuria/urinary incontinence and unrewarding sexual relationship (vaginal laxity patients) and atrophy-related symptoms including painful and unsatisfactory sexual activity (VVA/GSM patients). Participating women consistently reported wide-spectrum strong clinical improvements by the end of the planned DQRF sessions. Clinical improvements remained steady for the whole follow-up period in postmenopausal women; a statistically non-significant tendency to slight deterioration in VLQ, PISQ-12 and SSQ mean scores was detected after 6 to 9 months of follow-up in the vaginal laxity arm of the study. CONCLUSIONS: Safety was excellent during all DQRF procedures and over the 12 months following the end of the treatment sessions. VLQ, PISQ-12 and SSQ scores (women with vaginal laxity), VAS self-evaluation of VVA/GSM symptoms and overall satisfaction with sexual life (women with VVA/GSM symptoms) improved rapidly, reaching almost normal levels by the last DQRF session and suggesting rapid, but also persistent, vaginal rejuvenation in both indications. A late tendency to some slight deterioration in women treated for vaginal laxity suggests such women might benefit from new DQRF treatments 6 to 9 months after the previous cycle.

A method for the detection of virus infectivity in single cells and real time: Towards an automated fluorescence neutralization test.

Virus neutralizing antibodies are critical correlates of protection in vaccine development and are discriminatory in the plaque reduction neutralization test when used for the diagnosis of viral infections. However, neutralization assays are time consuming, labor intensive and highly variable, thus limiting their use. Advances in automated live imaging of cells opened new possibilities for standard virus diagnostic techniques such as neutralization assays. To this end, a reporter cell line based on the translocation of the transcription factor IRF3 in response to infection is proposed. Image acquisition of signal in a microplate format allowed the setup of a rapid, semi-automated and high-throughput fluorescent neutralization test. The study is extended to the live imaging of IRF3 translocations that could potentially cut the time of analysis to few hours. The fluorescent neutralization test is suitable for high-throughput assays and expandable to other viruses of global importance such as Zika virus.

Fourier transform infrared microspectroscopy reveals biochemical changes associated with glioma stem cell differentiation.

According to the cancer stem cell theory malignant glioma is incurable because of the presence of the cancer stem cells - a subpopulation of cells that are resistant to therapy and cause the recurrence of a tumor after surgical resection. Several protein markers of cancer stem cell were reported but none of those is fully reliable to grade the content of stem cells in a tumor. Hereby we propose Fourier transform infrared (FTIR) microspectroscopy as an alternative, labelfree, non-damaging and fast method to identify glioma stem cells based on their own spectral characteristics. The analysis of FTIR data revealed that in NCH421k cells, a model of glioma stem cells, the relative content of lipids is higher than in their all-trans retinoic acid-differentiated counterparts. Moreover, it has been assessed that stem cells have more rigid cellular membranes and more phosphorylated proteins, whereas after differentiation glycogen level increases. The ability of FTIR to estimate the content of stem cells in a heterogeneous sample, on the base of the identified spectral markers, and to classify stem and non-stem cells into two separate populations was probed. Although it was not possible to calculate the exact percentage of each subpopulation, we could clearly see that with the increasing amount of differentiated cells in a sample, more hits occupy the PC space previously identified as a space of differentiated cells. The present study is therefore an initial step towards the development of a FTIR based protocol in clinical practice to estimate the content of stem cells in a tumor sample.

Detection of HPV E7 oncoviral protein in cervical lesions by a new antibody.

The availability of a new E7 mAb-based immunohistochemistry (IHC) detection assay, Cervimax, allowed for the first time reliable testing of the E7 protein marker in formalin-fixed and paraffin-embedded tissues from cervical lesions. E7-specific IHC staining patterns were compared with those patterns of cervical cancer biomarkers, including the viral capsid protein L1 and the surrogate biomarkers p16INK4A, p53, hTERT, ubiquitin, and Ki67. The use of a tissue microarray of 138 cervical tissue cores from different pathologic stages allowed for a first profiling of the various markers in comparison with E7. Cervimax staining patterns closely overlap with those from p16INK4A and human telomerase reverse transcriptase (hTERT) in IHC staining for high-grade cervical intraepithelial neoplasia and squamous cell carcinoma. In squamous cell carcinoma, E7 immunostaining matched better to hTERT and ubiquitin profiles. On the contrary, the pattern of E7 and L1 were different in all the squamous lesions. The nuclear staining of E7 significantly discriminates between low-grade cervical intraepithelial neoplasia and high-grade cervical intraepithelial neoplasia in the basal, parabasal, and superficial layers. The results obtained in the presented pilot study suggest E7 as a valid candidate biomarker for all the stages of the malignant progression of cervical cancer; however, more extensive studies are needed to confirm the causal effect of the oncoprotein E7 in the diagnosis of human papillomavirus-induced diseases. These results also suggest that the diagnostic interpretation of cervical lesions could be increased by the combination of E7 and L1 staining in the evaluation of risk of progression, because related to different phases of viral integration.