Image quality and scan time optimisation for in situ phase contrast x-ray tomography of the intervertebral disc.

In-line phase contrast synchrotron tomography combined with in situ mechanical loading enables the characterisation of soft tissue micromechanics via digital volume correlation (DVC) within whole organs. Optimising scan time is important for reducing radiation dose from multiple scans and to limit sample movement during acquisition. Also, although contrasted edges provided by in-line phase contrast tomography of soft tissues are useful for DVC, the effect of phase contrast imaging on its accuracy has yet to be investigated. Due to limited time at synchrotron facilities, scan parameters are often decided during imaging and their effect on DVC accuracy is not fully understood. Here, we used previously published data of intervertebral disc phase contrast tomography to evaluate the influence of i) fibrous image texture, ii) number of projections, iii) tomographic reconstruction method, and iv) phase contrast propagation distance on DVC results. A greater understanding of how image texture influences optimal DVC tracking was obtained by visualising objective function mapping, enabling tracking inaccuracies to be identified. When reducing the number of projections, DVC was minimally affected by image high frequency noise but with a compromise in accuracy. Iterative reconstruction methods improved image signal-to-noise and consequently significantly lowered DVC displacement uncertainty. Propagation distance was shown to affect DVC accuracy. Consistent DVC results were achieved within a propagation distance range which provided contrast to the smallest scale features, where; too short a distance provided insufficient features to track, whereas too long led to edge effect inconsistencies, particularly at greater deformations. Although limited to a single sample type and image setup, this study provides general guidelines for future investigations when optimising image quality and scan times for in situ phase contrast x-ray tomography of fibrous connective tissues.

Regional variations in discrete collagen fibre mechanics within intact intervertebral disc resolved using synchrotron computed tomography and digital volume correlation.

Many soft tissues, such as the intervertebral disc (IVD), have a hierarchical fibrous composite structure which suffers from regional damage. We hypothesise that these tissue regions have distinct, inherent fibre structure and structural response upon loading. Here we used synchrotron computed tomography (sCT) to resolve collagen fibre bundles (∼5µm width) in 3D throughout an intact native rat lumbar IVD under increasing compressive load. Using intact samples meant that tissue boundaries (such as endplate-disc or nucleus-annulus) and residual strain were preserved; this is vital for characterising both the inherent structure and structural changes upon loading in tissue regions functioning in a near-native environment. Nano-scale displacement measurements along >10,000 individual fibres were tracked, and fibre orientation, curvature and strain changes were compared between the posterior-lateral region and the anterior region. These methods can be widely applied to other soft tissues, to identify fibre structures which cause tissue regions to be more susceptible to injury and degeneration. Our results demonstrate for the first time that highly-localised changes in fibre orientation, curvature and strain indicate differences in regional strain transfer and mechanical function (e.g. tissue compliance). This included decreased fibre reorientation at higher loads, specific tissue morphology which reduced capacity for flexibility and high strain at the disc-endplate boundary. STATEMENT OF SIGNIFICANCE: The analyses presented here are applicable to many collagenous soft tissues which suffer from regional damage. We aimed to investigate regional intervertebral disc (IVD) structural and functional differences by characterising collagen fibre architecture and linking specific fibre- and tissue-level deformation behaviours. Synchrotron CT provided the first demonstration of tracking discrete fibres in 3D within an intact IVD. Detailed analysis of regions was performed using over 200k points, spaced every 8 µm along 10k individual fibres. Such comprehensive structural characterisation is significant in informing future computational models. Morphological indicators of tissue compliance (change in fibre curvature and orientation) and fibre strain measurements revealed localised and regional differences in tissue behaviour.

Low-to-moderate alcohol consumption and success in fertility treatment: a Danish cohort study.

STUDY QUESTION: Does female weekly alcohol intake and binge drinking impact the chance of a successful fertility treatment? SUMMARY ANSWER: Low-to-moderate weekly alcohol drinking and binge drinking were not associated with the chance of achieving a clinical pregnancy or a live birth among women and couples undergoing medically assisted reproduction (MAR) treatments. WHAT IS KNOWN ALREADY: Alcohol consumption is common among women of reproductive age, even though health authorities advise women trying to conceive to abstain from drinking. A growing number of couples struggle with infertility, but it is unknown whether low-to-moderate levels of alcohol consumption and alcohol binge drinking impair success in fertility treatment. STUDY DESIGN, SIZE, DURATION: Cohort study with prospectively collected exposure information including 1708 women and potential partners undergoing fertility treatment at the public fertility clinic, Aarhus University Hospital, 1 January 2010 to 31 August 2015. In total, data on 1511 intrauterine insemination (IUI) cycles, 2870 in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles and 1355 frozen embryo transfer cycles. PARTTICIPANTS/MATERIALS, SETTING, METHODS: Exposure to weekly average alcohol intake was assessed from questionnaires completed by participants before the start of treatment. Outcome measures are the achievement of a clinical pregnancy and live birth in consecutive treatment cycles in the Danish national health registries, enabling complete follow-up. A modified Poisson regression with robust standard errors was used to evaluate associations between a weekly average alcohol intake and MAR outcomes, adjusting for female age, body mass index, cigarette smoking, coffee consumption, chronic diseases, level of education, and cycle number. When evaluating the association between binge drinking in the month prior to baseline and MAR outcomes the analyses were further adjusted for average weekly alcohol consumption. MAIN RESULTS AND THE ROLE OF CHANCE: Low-to-moderate average weekly alcohol intake was not statistically significantly associated with the chance of achieving a clinical pregnancy or a live birth following IUI or IVF/ICSI treatment cycles. Compared to women abstaining from alcohol, the adjusted relative risks for achieving a live birth among those reporting 1-2, 3-7, and >7 drinks per week were 1.00 (95% CI 0.66; 1.53), 1.20 (0.76; 1.91), and 1.48 (0.56; 3.93), respectively, among women initiating IUI treatments. Among those initiating IVF/ICSI treatments, the chance for achieving a live birth among those reporting 1-2, 3-7, and >7 drinks per week were 1.00 (0.83; 1.21), 0.95 (0.75; 1.20), and 0.89 (0.53; 1.51), respectively. The chance of achieving a live birth in the first IUI or IVF/ICSI treatment cycle was unrelated to the number of binge drinking episodes in the month preceding baseline. LIMITATIONS, REASONS FOR CAUTION: The risk of non-differential exposure misclassification, confounding, or chance cannot be ruled out. In addition, due to the low number of women reporting an intake of >7 drinks/week, the potential effect of high alcohol consumption should be interpreted with caution. WIDER IMPLICATIONS OF THE FINDINGS: Although it remains unsettled if and how alcohol affects female reproduction, our results indicate that is not necessary to abstain from alcohol when striving for a successful outcome following fertility treatment. STUDY FUNDING/COMPETING INTEREST(S): J.L. is supported by a fully financed Ph.D. scholarship from Aarhus University and has received funds from the A.P. Møller foundation. The funding sources had no involvement in the conduct of the article. Dr Kesmodel reports personal fees from MSD and Ferring Pharmaceuticals outside the submitted work. All other authors have no conflicts of interest to declare and all have completed the ICMJE disclosure form. TRIAL REGISTRATION NUMBER: Not relevant.

Synchrotron tomography of intervertebral disc deformation quantified by digital volume correlation reveals microstructural influence on strain patterns.

The intervertebral disc (IVD) has a complex and multiscale extracellular matrix structure which provides unique mechanical properties to withstand physiological loading. Low back pain has been linked to degeneration of the disc but reparative treatments are not currently available. Characterising the disc's 3D microstructure and its response in a physiologically relevant loading environment is required to improve understanding of degeneration and to develop new reparative treatments. In this study, techniques for imaging the native IVD, measuring internal deformation and mapping volumetric strain were applied to an in situ compressed ex vivo rat lumbar spine segment. Synchrotron X-ray micro-tomography (synchrotron CT) was used to resolve IVD structures at microscale resolution. These image data enabled 3D quantification of collagen bundle orientation and measurement of local displacement in the annulus fibrosus between sequential scans using digital volume correlation (DVC). The volumetric strain mapped from synchrotron CT provided a detailed insight into the micromechanics of native IVD tissue. The DVC findings showed that there was no slipping at lamella boundaries, and local strain patterns were of a similar distribution to the previously reported elastic network with some heterogeneous areas and maximum strain direction aligned with bundle orientation, suggesting bundle stretching and sliding. This method has the potential to bridge the gap between measures of macro-mechanical properties and the local 3D micro-mechanical environment experienced by cells. This is the first evaluation of strain at the micro scale level in the intact IVD and provides a quantitative framework for future IVD degeneration mechanics studies and testing of tissue engineered IVD replacements. STATEMENT OF SIGNIFICANCE: Synchrotron in-line phase contrast X-ray tomography provided the first visualisation of native intact intervertebral disc microstructural deformation in 3D. For two annulus fibrosus volumes of interest, collagen bundle orientation was quantified and local displacement mapped as strain. Direct evidence of microstructural influence on strain patterns could be seen such as no slipping at lamellae boundaries and maximum strain direction aligned with collagen bundle orientation. Although disc elastic structures were not directly observed, the strain patterns had a similar distribution to the previously reported elastic network. This study presents technical advances and is a basis for future X-ray microscopy, structural quantification and digital volume correlation strain analysis of soft tissue.

Therapeutic Prospects in Preeclampsia - A Mini-Review.

BACKGROUND: Preeclapmsia (PE) is characterized by early onset symptoms such as elevated blood pressure, proteinuria and edema in the pregnant woman, and may result in seizures in the affected female. Currently, there are no therapeutic drugs available to treat this condition, but there are interventions to regulate the symptoms based on the gestational period of the fetus, although the largely favored option is delivery of the fetus and placenta. OBJECTIVE: A search for biomolecules associated with PE was conducted so as to identify diagnostic markers and therapeutic leads. RESULTS: The literature search resulted in the identification of biomolecules such as Corin and Placental Protein 13 (PP13), among others that are associated with PE. Thereby, giving an insight into the various mechanistic pathways involved in the causation of PE. However, it is also evident that PE cannot be solely attributed to any single mechanism but is due to an interplay of different factors that have led to the development of this disease condition. CONCLUSION: The identified biomarkers would ultimately help in understanding this complex disease and perhaps lead to the discovery of potential effective molecular targets for clinical trials, thereby providing a valuable therapeutic option for affected pregnant women.

Risk of stillbirth in low-risk singleton term pregnancies following fertility treatment: a national cohort study.

OBJECTIVE: To assess the risk of stillbirth in low-risk in vitro fertilisation (IVF) pregnancies. DESIGN: Register-based national cohort study. SETTING: Denmark 2003-2013. POPULATION: Cohort of 425 732 singleton pregnancies including 10 235 conceived following IVF/intracytoplasmic sperm injection (ICSI), 4521 conceived following intrauterine insemination (IUI), and 410 976 spontaneously conceived. METHODS: Information on pregnancy, obstetrical risk factors, stillbirth, and fertility treatment was obtained from the Danish national health registers for all pregnancies after gestational week 21+6 . We estimated the overall and gestational age-specific risk of stillbirth in low-risk term pregnancies following IVF, ICSI, and IUI. Further, we estimated the association between stillbirth and IVF and ICSI respectively as well as fresh or frozen-thawed embryo transfer. MAIN OUTCOME MEASURES: Risk of stillbirth. RESULTS: The number of stillbirths in spontaneously conceived and IVF/ICSI low-risk term pregnancies was 525 (0.1%) and 35 (0.3%), respectively. In multivariate analysis, the risk of stillbirth in pregnancies following IVF/ICSI was increased (odds ratio 2.1, 95% CI 1.4-3.1). The risk of stillbirth was correspondingly increased in time-to-event analyses taking risk time for each fetus into account from gestational week 37 and onwards (hazard ratio 2.4, 95% CI 1.6-3.6). In sub-analyses, the risk of stillbirth was increased for pregnancies following ICSI (odds ratio 2.2, 95% CI 1.2-3.1), but not IVF (odds ratio 1.7, 95% CI 0.9-3.1). CONCLUSION: We found a systematically increased risk of stillbirth in low-risk term pregnancies following IVF/ICSI. Whether the risk was related to the treatment or to underlying subfertility is uncertain. The results may indicate a need for obstetrical surveillance for these pregnancies when reaching term. TWEETABLE ABSTRACT: Increased risk of stillbirth in low-risk term pregnancies following fresh cycle IVF/ICSI.

Childhood growth of singletons conceived following in vitro fertilisation or intracytoplasmic sperm injection: a systematic review and meta-analysis.

BACKGROUND: Assisted reproductive techniques are associated with an increased risk of adverse pregnancy outcomes, including low birthweight and intrauterine growth restriction. Yet, the long-term follow-up on the growth of these children is limited. OBJECTIVE: To systematically review the literature on post-neonatal height and weight among children conceived following in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment, compared with that of children born after spontaneous conception. SEARCH STRATEGY: A systematic computerised literature search using the online databases PubMed, Embase, and Scopus. SELECTION CRITERIA: Cohort or case-control studies with an exposed group of singletons conceived following IVF or ICSI along with a control group of spontaneously conceived singletons. DATA COLLECTION AND ANALYSIS: Studies were reviewed by at least two authors. Meta-analyses were conducted using Cochrane Review Manager. The quality of the studies was assessed with the Newcastle-Ottawa Scale. MAIN RESULTS: Twenty studies were included, with 13 of these eligible for meta-analyses. The meta-analyses compared 3972 children born after IVF/ICSI with 11 012 spontaneously conceived children and revealed no statistically significant difference in child weight [mean difference (MD) in weight of -160 g; 95% confidence interval (95% CI) -360, 3]. When stratifying by age of child at follow-up, we found a significant lower weight in children aged 0-4 years conceived following IVF/ICSI treatment (MD -180 g; 95% CI -320, -4), but this was no longer significant in children from 5 years of age (MD -160 g; 95% CI -580, 260). The pooled analysis revealed no statistically significant difference in childhood height. CONCLUSIONS: In vitro fertilisation/ICSI was not associated with long-term weight and height. TWEETABLE ABSTRACT: Children born following IVF/ICSI do not have impaired long-term weight or height compared with spontaneously conceived children.

A review of techniques for visualising soft tissue microstructure deformation and quantifying strain Ex Vivo.

Many biological tissues have a complex hierarchical structure allowing them to function under demanding physiological loading conditions. Structural changes caused by ageing or disease can lead to loss of mechanical function. Therefore, it is necessary to characterise tissue structure to understand normal tissue function and the progression of disease. Ideally intact native tissues should be imaged in 3D and under physiological loading conditions. The current published in situ imaging methodologies demonstrate a compromise between imaging limitations and maintaining the samples native mechanical function. This review gives an overview of in situ imaging techniques used to visualise microstructural deformation of soft tissue, including three case studies of different tissues (tendon, intervertebral disc and artery). Some of the imaging techniques restricted analysis to observational mechanics or discrete strain measurement from invasive markers. Full-field local surface strain measurement has been achieved using digital image correlation. Volumetric strain fields have successfully been quantified from in situ X-ray microtomography (micro-CT) studies of bone using digital volume correlation but not in soft tissue due to low X-ray transmission contrast. With the latest developments in micro-CT showing in-line phase contrast capability to resolve native soft tissue microstructure, there is potential for future soft tissue mechanics research where 3D local strain can be quantified. These methods will provide information on the local 3D micromechanical environment experienced by cells in healthy, aged and diseased tissues. It is hoped that future applications of in situ imaging techniques will impact positively on the design and testing of potential tissue replacements or regenerative therapies. LAY DESCRIPTION: The soft tissues in our bodies, such as tendons, intervertebral discs and arteries, have evolved to have complicated structures which deform and bear load during normal function. Small changes in these structures can occur with age and disease which then leads to loss of function. Therefore, it is important to image tissue microstructure in 3D and under functional conditions. This paper gives an overview of imaging techniques used to record the deformation of soft tissue microstructures. Commonly there are compromises between obtaining the best imaging result and retaining the samples native structure and function. For example, invasive markers and dissecting samples damages the tissues natural structure, and staining or clearing (making the tissue more transparent) can distort tissue structure. Structural deformation has been quantified from 2D imaging techniques (digital image correlation) to create surface strain maps which help identify local tissue mechanics. When extended to 3D (digital volume correlation), deformation measurement has been limited to bone samples using X-ray micro-CT. Recently it has been possible to image the 3D structure of soft tissue using X-ray micro-CT meaning that there is potential for internal soft tissue mechanics to be mapped in 3D. Future application of micro-CT and digital volume correlation will be important for soft tissue mechanics studies particularly to understand normal function, progression of disease and in the design of tissue replacements.

Histone Modifications as Molecular Targets in Nasopharyngeal Cancer.

Nasopharyngeal carcinoma (NPC) is a cancer of the nasopharyngeal epithelium with distinct geographical, ethnic and racial distribution. Several genetic, ethnic and environmental risk factors, have been implicated in nasopharyngeal pathogenesis and of significance, is the Epstein - Barr virus (EBV)- latent infection observed in most patients. Patients with NPC are typically diagnosed only in advanced stages due to non-specific symptoms, and hence, they respond poorly to therapy. Currently, low survival rates, severe complications, tumour metastasis and recurrence following chemo-radiotherapy, delineate the need for better therapeutic options to combat the disease. Recent studies have shown that epigenetic mechanisms such as DNA methylation, histone modifications and microRNAs, which are altered in the EBV genome as well as in the host cells, may underlie the initiation and progression of NPC. Histone acetylation and deacetylation which are mediated by enzymes, namely histone acetyl transferases (HATs) and histone deacetylases (HDACs), are known to regulate gene expression and several cellular processes. HDACs are also involved in maintaining the EBV latent cycle and thus, HDAC inhibitors (HDACi) are potent inducers of EBV reactivation, which is critical for the expression of the lytic proteins, thereby providing novel targets for therapy, as well as mediating enhanced killing of cancer cells, when used alone or along with additional anti-cancer agents in EBV associated malignancies. Recently, three FDA- approved HDACi have been used for the treatment of T-cell lymphoma, while several others are in clinical trials, making histone modifications excellent candidates for targeted therapy. In this review, we summarize the epigenetic mechanisms altered in NPC, with a focus on histone modifications for targeted therapy.

Synthesis, characterization and theoretical studies of 5-(benzylthio)-1-cylopentyl-1H-tetrazole.

In this study, 5-(benzylthio)-1-cylopentyl-1H-tetrazole (5B1C1HT) have been synthesized. Boiling points of the obtained compound have been determined and it has been characterized by FT-IR, (1)H NMR, (13)C-APT and LC-MS spectroscopy techniques. The FT-IR, (1)H NMR and (13)C-APT spectral measurements of the 5B1C1HT compound and complete assignment of the vibrational bands observed in spectra has been discussed. The spectra were interpreted with the aid of normal coordinate analysis following full structure optimization and force field calculations based on Density Functional Theory (DFT) at 6-311++G(**), cc-pVDZ and cc-pVTZ basis sets. The optimized geometry with 6-311++G(**) basis sets were used to determine the total energy distribution, harmonic vibrational frequencies, IR intensities.

The association of pre-pregnancy alcohol drinking with child neuropsychological functioning.

OBJECTIVE: To examine the effects of pre-pregnancy alcohol drinking on child neuropsychological functioning. DESIGN: Prospective follow-up study. SETTING AND POPULATION: 154 women and their children sampled from the Danish National Birth Cohort. METHODS: Participants were sampled based on maternal alcohol consumption before pregnancy. At 5 years of age, the children were tested with the Wechsler Preschool and Primary Scale of Intelligence-Revised, the Test of Everyday Attention for Children at Five (TEACh-5), and the Movement Assessment Battery for Children (MABC). The Behaviour Rating Inventory of Executive Function (BRIEF) was completed by the mothers and a preschool teacher. Parental education, maternal IQ, prenatal maternal smoking, child's age at testing, child's sex, and maternal alcohol intake during pregnancy were considered potential confounders. MAIN OUTCOME MEASURES: Performance on the Wechsler Preschool and Primary Scale of Intelligence-Revised, the TEACh-5, the MABC, and the BRIEF. RESULTS: Intake of 15-21 drinks/week on average prior to pregnancy was not associated with any of the outcomes, but intake of ≥22 drinks/week on average was associated with a significantly lower adjusted mean full scale IQ and lower adjusted means in overall attention and sustained attention score, but not in selective attention score or any of the BRIEF index scores or MABC scores. CONCLUSIONS: Intake of ≥22 drinks/week before pregnancy was associated with lower mean full scale IQ, overall attention and sustained attention. Assessment of pre-pregnancy drinking provides additional information regarding potential prenatal alcohol exposure and its implications for child neurodevelopment.

Fertility treatment and child intelligence, attention, and executive functions in 5-year-old singletons: a cohort study.

OBJECTIVE: To assess the association of fertility treatment and subfertility with offspring intelligence, attention, and executive functions in 5-year-old singletons. DESIGN: Follow-up study. SETTING: Denmark 2003-2008. POPULATION: A cohort of 1782 children sampled from the Danish National Birth Cohort. METHODS: The children were tested with a neuropsychological battery at age five. In addition to tests of intelligence, attention and executive functions, the follow up included extensive information on important covariates. The analyses were conducted using multiple linear regression and adjusted for parental educational level, maternal intelligence, age, parity, body mass index, smoking in pregnancy, alcohol consumption in pregnancy and child gender, child age, and examiner. MAIN OUTCOME MEASURES: Wechsler Preschool and Primary Scale of Intelligence-Revised, the Test of Everyday Attention for Children at Five, and the Behavior Rating Inventory of Executive Functions scores. RESULTS: A consistent pattern of nonsignificantly lower scores were only observed for intelligence and executive functions in children born after fertility treatment or by subfertile parents when the results were unadjusted for maternal intelligence and parental educational level. When adjusted for these and other covariates, there were no significant mean differences in intelligence (mean difference -2.8, 95% CI -7.8, 2.2), overall attention (-0.1, 95% CI -0.6, 0.3), or parent-rated executive functions (-0.1, 95% CI -3.0, 2.9) between children born after spontaneous conception and children born to parents conceiving after fertility treatment. Similarly, there were no significant mean differences in intelligence (mean difference 0.6, 95% CI -2.2, 3.4), overall attention (0.1, 95% CI -0.2, 0.4), or parent-rated executive functions (1.0, 95% CI -1.8, 3.7) between children born after spontaneous conception and children born to subfertile parents waiting more than 12 months before conceiving naturally. CONCLUSIONS: This study suggests that parental subfertility and fertility treatment are unrelated to offspring intelligence, attention and executive functions.

Growth factor treated tensioned synoviocyte neotissues: towards meniscal bioscaffold tissue engineering.

Meniscal injury is a common cause of osteoarthritis, pain, and disability in dogs and humans, but tissue-engineered bioscaffolds could be a treatment option for meniscal deficiency. The objective of this study was to compare meniscus-like matrix histology, composition, and biomechanical properties of autologous tensioned synoviocyte neotissues (TSN) treated with fetal bovine serum (TSNfbs) or three chondrogenic growth factors (TSNgf). Fourth passage canine synoviocytes from 10 dogs were grown in hyperconfluent monolayer culture, formed into TSN, and then cultured for 3 weeks with 17.7% FBS or three human recombinant TSNgf (bFGF, TGF-ß1, and IGF-1). Cell viability was determined with laser microscopy. Histological architecture and the composition of fibrocartilage matrix were evaluated in TSN by staining tissues for glycosaminoglycan (GAG), α-smooth muscle actin, and collagen 1 and 2; quantifying the content of GAG, DNA, and hydroxyproline; and measuring the gene expression of collagens type 1α and 2α, the GAG aggrecan, and transcription factor Sry-type Homeobox Protein-9 (SOX9). Biomechanical properties were determined by materials testing force-deformation curves. The TSN contained components and histological features of mensical fibrocartilage extracellular matrix. Growth factor-treated TSN had higher DNA content but lower cell viability than TSNfbs. TSNgf had greater fibrocartilage-like matrix content (collagen 2 and GAG content with increased collagen 2α and SOX9 gene expression). Additionally, TSNgf collagen was more organized histologically and so had greater tensile biomechanical properties. The results indicate the potential of TSN when cultured with growth factors as implantable bioscaffolds for the treatment of canine meniscal deficiency.

Evidence of mitochondrial dysfunction and impaired ROS detoxifying machinery in Fanconi anemia cells.

Fanconi Anemia (FA) is a rare genetic disorder associated with a bone-marrow failure, cancer predisposition and hypersensitivity to DNA crosslinking agents. Majority of the 15 FA genes and encoded proteins characterized so far are integrated into DNA repair pathways, however, other important functions cannot be excluded. FA cells are sensitive to oxidants, and accumulation of oxidized proteins has been characterized for several FA subgroups. Clinical phenotypes of both FA and other closely related diseases suggest altered functions of mitochondria, organelles responsible for cellular energetic metabolism, and also serving as an important producer and the most susceptible target from reactive oxidative species (ROS). In this study, we have shown that elevated level of mitochondrial ROS in FA cells is in parallel with the decrease of mitochondrial membrane potential, the decrease of ATP production, impaired oxygen uptake and pathological changes in the morphology of mitochondria. This is accompanied by inactivation of enzymes that are essential for the energy production (F1F0ATPase and cytochrome C oxidase) and detoxification of ROS (superoxide dismutase, SOD1). In turn, overexpression of SOD1 could rescue oxygen consumption rate in FA-deficient cells. Importantly, the depletion of mitochondria improved survival rate of mitomycin C treated FA cells suggesting that hypersensitivity of FA cells to chemotherapeutic drugs could be in part due to the mitochondria-mediated oxidative stress. On the basis of our results, we propose that deficiency in FA genes lead to disabling mitochondrial ROS-scavenging machinery further affecting mitochondrial functions and suppressing cell respiration.

Silver nanoparticles in cancer: therapeutic efficacy and toxicity.

In recent years, there has been escalating interest in the biomedical applications of nanoparticles (NPs). In particular, silver nanoparticles (AgNPs) are increasingly being investigated as tools for novel cancer therapeutics, capitalizing on their unique properties to enhance potential therapeutic efficacy. However, questions as to are we able to contain or control the toxicity effects of AgNPs, and how much do we know about the toxicological profile of AgNPs which are commonly used in emerging nanotechnology-based applications, still remain. Hence, serious considerations have to be given to the hazards and risks of toxicity associated with the use of AgNPs. This review focuses on the current applications of AgNPs, their known effects and toxicity, as well as the potential of harnessing them for use in cancer therapy.

Parafibromin expression in breast cancer: a novel marker for prognostication?

BACKGROUND: Parafibromin is a novel protein product of HRPT2, a recently identified tumour suppressor gene. Mutations of the HRPT2 gene are common in parathyroid carcinomas, and these exhibit reduced protein expression. Parafibromin expression in breast cancer has not been previously studied. AIMS: To determine the distribution of parafibromin in breast cancer tissues, and correlate its expression with conventional pathological parameters. METHODS: Tissue microarrays were constructed from archival paraffin embedded breast cancer samples. Sections cut from tissue microarray blocks were subjected to immunohistochemistry. Immunopositivity for parafibromin and intensity-percentage scores were derived by blinded evaluation. Findings were correlated with clinicopathological parameters. RESULTS: 163 breast cancers were assessed. Larger tumours were less likely to express parafibromin than smaller ones, with the association approaching statistical significance (p = 0.05). Staining intensity correlated inversely with tumour size (p = 0.016) and pathological stage (p = 0.008); as did parafibromin intensity-percentage score with pathological stage (p = 0.03), lymphovascular invasion (p = 0.03) and cerbB2 intensity-percentage score (p = 0.04). CONCLUSION: Parafibromin in breast cancer, as in parathyroid tumours, appears to have tumour suppressor functions, with loss of protein expression associated with adverse pathological parameters. These findings may indicate a potential role of parafibromin as a prognostic marker in breast cancer.

Mucinous breast lesions: diagnostic challenges.

Breast lesions with mucin represent a broad spectrum of entities, ranging from benign fibrocystic changes with luminal mucin to mucocele-like lesions (MLL), which can be associated with banal epithelial alterations, atypical ductal hyperplasia or ductal carcinoma in situ. Occasionally invasive mucinous carcinoma can be identified in contiguity with MLL. Diagnostic challenges are enumerated, histological differentials are discussed, and a practical approach towards resolving some of these issues is provided. In addition to these lesions with abundant extracellular mucin, there are also conditions that feature stromal mucinous or myxoid material, as well as rare entities that demonstrate both epithelial extracellular and stromal mucin.

Hypericin photoactivation triggers down-regulation of matrix metalloproteinase-9 expression in well-differentiated human nasopharyngeal cancer cells.

Recently, we have shown that hypericin-mediated photodynamic therapy (PDT) is a promising modality for the treatment of nasopharyngeal cancer (NPC). The present study evaluated the expression of matrix metalloproteinase-9 (MMP-9) following hypericin-PDT in well-differentiated HK1 NPC cells. Down-regulation of MMP-9 by hypericin-PDT was observed at the mRNA level in HK1 cells in vitro and in vivo and at the protein level in vitro. Transcriptional activities of the activator protein-1 (AP-1) and nuclear factor (NF)-kappaB regulatory elements were inhibited by PDT. We also found that PDT reduced secreted granulocyte-macrophage colony stimulating factor (GM-CSF), which is known to activate transcription of NK-kappaB and AP-1. However, incubation of untreated HK1 cells with exogenous GM-CSF abrogated the reduction of MMP-9 production in hypericin-PDT-treated cells. It would appear that PDT downregulates MMP-9 expression via inhibition of GM-CSF production, which in turn modulates AP1/NF-kappaB transcriptional activities. Suppression of MMP-9 by hypericin-PDT may have therapeutic implications.

Evaluation of electrospun PCL/gelatin nanofibrous scaffold for wound healing and layered dermal reconstitution.

The current design requirement for a tissue engineering skin substitute is that of a biodegradable scaffold through which fibroblasts can migrate and populate. This artificial "dermal layer" needs to adhere to and integrate with the wound, which is not always successful for the current artificial dermal analogues available. The high cost of these artificial dermal analogues also makes their application prohibitive both to surgeons and patients. We propose a cost-effective composite consisting of a nanofibrous scaffold directly electrospun onto a polyurethane dressing (Tegaderm, 3M Medical) - which we call the Tegaderm-nanofiber (TG-NF) construct - for dermal wound healing. Cell culture is performed on both sides of the nanofibrous scaffold and tested for fibroblast adhesion and proliferation. It is hoped that these studies will result in a fibroblast-populated three-dimensional dermal analogue that is feasible for layered applications to build up thickness of dermis prior to re-epithelialization. Results obtained in this study suggest that both the TG-NF construct and dual-sided fibroblast-populated nanofiber construct achieved significant cell adhesion, growth and proliferation. This is a successful first step for the nanofiber construct in establishing itself as a suitable three-dimensional scaffold for autogenous fibroblast populations, and providing great potential in the treatment of dermal wounds through layered application.