50 research outputs found
The effects and mechanisms of paeoniflorin on murine ovarian cells for the treatment of polycystic ovarian syndrome
University of Technology Sydney. Faculty of Science.Polycystic Ovarian Syndrome (PCOS) is a complex disorder associated with various reproductive, metabolic and cardiovascular abnormalities and is present in approximately 15% of women of reproductive age. The hallmarks include androgen excess, ovulatory dysfunction and insulin resistance which is believed to play a role in the pathogenesis of the disorder. Although the exact mechanisms of PCOS are unknown, intrinsic dysfunction of ovarian theca and granulosa cells are also thought to contribute to altered steroid production and follicle development which may explain the clinical features of the syndrome.
Metformin, an insulin sensitising agent may improve both metabolic and reproductive aspects of the disorder, however, the development of new therapeutic agents for PCOS is still required. Women with PCOS are inclined to seek complementary and alternative treatment options such as Chinese Herbal Medicine, warranting further investigation into the efficacy of the herbs commonly used. Paeoniflorin, the major compound of the herb, Radix Paeoniae Albus has demonstrated the ability to ameliorate insulin resistance in animal models, however the effects and mechanisms of paeoniflorin for the treatment of PCOS has yet to be elucidated.
This study therefore used a dexamethasone-induced in vitro model of PCOS in murine theca and granulosa cells to determine the effects of paeoniflorin on secretion of key hormones testosterone, progesterone and oestradiol, cell proliferation as well as the molecular mechanisms in which paeoniflorin may regulate steroid production. Dexamethasone (10 ”M) increased theca cell androgen production and adversely affected oestradiol: progesterone ratios in granulosa cells. Meanwhile, paeoniflorin (100 ”g/mL) decreased androgen production in dexamethasone-induced theca cells and maintained normal oestradiol: progesterone ratios in granulosa cells. In theca cells, this was shown to be through downregulation of cholesterol side-chain cleavage enzyme and 17,20-lyase protein expression. Paeoniflorin also increased mRNA gene expression of CYP11A1 which may indicate influence over transcription factors or post-translation modifiers, particularly in relation to cell differentiation.
Together, these results suggest that firstly, dexamethasone can be considered a useful in vitro model of PCOS in murine ovarian cells. Secondly, paeoniflorin may be a novel agent for the treatment of PCOS by ameliorating hyperandrogenism and improving ovarian function. Further research into the effect of paeoniflorin in differentiation of theca cells as well as the molecular mechanisms in which paeoniflorin attenuates hormones in granulosa cells is needed. Finally, this research can potentially support future animal or clinical studies to further improve the treatment options and quality of life for women with PCOS
Deciphering complex metabolite mixtures by unsupervised and supervised substructure discovery and semi-automated annotation from MS/MS spectra
Complex metabolite mixtures are challenging to unravel. Mass spectrometry (MS) is a widely
used and sensitive technique to obtain structural information on complex mixtures. However, just
knowing the molecular masses of the mixtureâs constituents is almost always insufficient for
confident assignment of the associated chemical structures. Structural information can be
augmented through MS fragmentation experiments whereby detected metabolites are
fragmented giving rise to MS/MS spectra. However, how can we maximize the structural
information we gain from fragmentation spectra?
We recently proposed a substructure-based strategy to enhance metabolite annotation for
complex mixtures by considering metabolites as the sum of (bio)chemically relevant moieties that
we can detect through mass spectrometry fragmentation approaches. Our MS2LDA tool allows
us to discover - unsupervised - groups of mass fragments and/or neutral losses termed
Mass2Motifs that often correspond to substructures. After manual annotation, these Mass2Motifs
can be used in subsequent MS2LDA analyses of new datasets, thereby providing structural
annotations for many molecules that are not present in spectral databases.
Here, we describe how additional strategies, taking advantage of i) combinatorial in-silico
matching of experimental mass features to substructures of candidate molecules, and ii)
automated machine learning classification of molecules, can facilitate semi-automated annotation
of substructures. We show how our approach accelerates the Mass2Motif annotation process and
therefore broadens the chemical space spanned by characterized motifs. Our machine learning
model used to classify fragmentation spectra learns the relationships between fragment spectra
and chemical features. Classification prediction on these features can be aggregated for all
molecules that contribute to a particular Mass2Motif and guide Mass2Motif annotations.
To make annotated Mass2Motifs available to the community, we also present motifDB: an open
database of Mass2Motifs that can be browsed and accessed programmatically through an
Application Programming Interface (API). MotifDB is integrated within ms2lda.org, allowing users
to efficiently search for characterized motifs in their own experiments. We expect that with an
increasing number of Mass2Motif annotations available through a growing database we can more
quickly gain insight in the constituents of complex mixtures. That will allow prioritization towards
novel or unexpected chemistries and faster recognition of known biochemical building blocks
Opposing associations of stress and resilience with functional outcomes in stroke survivors in the chronic phase of stroke: A cross-sectional study
Stroke survivors report significant levels of psychological distress post stroke. To date, most studies conducted have focused on the relationship between psychological stress and functional outcomes in the acute phase of stroke. However, no studies had considered the role of stress over the chronic phase, where stress may continue to exert negative effects on cognitive and psychological processes. Further, the role of potentially modulatory variables, such as psychological resilience, on stroke outcomes has been understudied. The purpose of this study was to consider the relationships between stress and resilience with functional outcomes in long-term survivors of stroke. People (N = 70) who had experienced a stroke between 5 months and 28 years ago were included in the cross-sectional study, along with age-matched controls (N = 70). We measured stress using both the Perceived Stress Scale and biological markers, and resilience using both the Brief Resilience Scale and the Connor-Davidson Resilience Scale. Stroke outcomes were assessed using the Stroke Impact Scale. We found that, compared with age-matched controls, stroke survivors reported greater levels of perceived stress, and lower levels of resilience. In stroke survivors, both perceived stress and resilience were independently associated with stroke outcomes in linear regression models. In particular, these relationships were observed for cognitive outcomes including mood, memory, and communication. The association between stress and stroke outcome did not differ across time post stroke. Given that resilience is a modifiable psychological construct, future research may consider whether strategies directed at enhancing resilience may improve recovery from stroke
Therminator DNA Polymerase: Modified Nucleotides and Unnatural Substrates
A variant of 9°N DNA polymerase [Genbank ID (AAA88769.1)] with three mutations (D141A, E143A, A485L) and commercialized under the name âTherminator DNA polymeraseâ has the ability to incorporate a variety of modified nucleotide classes. This Review focuses on how Therminator DNA Polymerase has enabled new technologies in synthetic biology and DNA sequencing. In addition, we discuss mechanisms for increased modified nucleotide incorporation
Medical communication and technology: a video-based process study of the use of decision aids in primary care
Background: much of the research on decision-making in health care has focused on consultation outcomes. Less is known about the process by which clinicians and patients come to a treatment decision. This study aimed to quantitatively describe the behaviour shown by doctors and patients during primary care consultations when three types of decision aids were used to promote treatment decision-making in a randomised controlled trial.Methods: a video-based study set in an efficacy trial which compared the use of paper-based guidelines (control) with two forms of computer-based decision aids (implicit and explicit versions of DARTS II). Treatment decision concerned warfarin anti-coagulation to reduce the risk of stroke in older patients with atrial fibrillation. Twenty nine consultations were video-recorded. A ten-minute 'slice' of the consultation was sampled for detailed content analysis using existing interaction analysis protocols for verbal behaviour and ethological techniques for non-verbal behaviour.Results: median consultation times (quartiles) differed significantly depending on the technology used. Paper-based guidelines took 21 (19â26) minutes to work through compared to 31 (16â41) minutes for the implicit tool; and 44 (39â55) minutes for the explicit tool. In the ten minutes immediately preceding the decision point, GPs dominated the conversation, accounting for 64% (58â66%) of all utterances and this trend was similar across all three arms of the trial. Information-giving was the most frequent activity for both GPs and patients, although GPs did this at twice the rate compared to patients and at higher rates in consultations involving computerised decision aids. GPs' language was highly technically focused and just 7% of their conversation was socio-emotional in content; this was half the socio-emotional content shown by patients (15%). However, frequent head nodding and a close mirroring in the direction of eye-gaze suggested that both parties were active participants in the conversationConclusion: irrespective of the arm of the trial, both patients' and GPs' behaviour showed that they were reciprocally engaged in these consultations. However, even in consultations aimed at promoting shared decision-making, GPs' were verbally dominant, and they worked primarily as information providers for patients. In addition, computer-based decision aids significantly prolonged the consultations, particularly the later phases. These data suggest that decision aids may not lead to more 'sharing' in treatment decision-making and that, in their current form, they may take too long to negotiate for use in routine primary car
STAT5 drives abnormal proliferation in autosomal dominant polycystic kidney disease.
Autosomal dominant polycystic kidney disease (ADPKD) leads to renal failure. The hallmark of ADPKD is increased epithelial proliferation, which has been proposed to be due to atypical signaling including abnormal JAK-STAT activity. However, the relative contribution of JAK-STAT family members in promoting proliferation in ADPKD is unknown. Here, we present siRNA JAK-STAT-focused screens discovering a previously unknown proliferative role for multiple JAK-STAT components (including STAT1, STAT2, STAT4, STAT5a, and STAT5b). Amongst these, we selected to study the growth hormone/growth hormone receptor/STAT5-axis because of its known role as a regulator of growth in nonrenal tissues. Loss of STAT5 function, facilitated by pharmacological inhibition or siRNAs, significantly reduced proliferation with an associated reduction in cyst growth in vitro. To study whether STAT5 is abnormally activated in vivo, we analyzed its expression using two independent mouse models of ADPKD. STAT5 was nuclear, thus activated, in renal epithelial cyst lining cells in both models. To test whether forced activation of STAT5 can modulate proliferation of renal cells in vivo, irrespective of the Pkd1 status, we overexpressed growth hormone. These mice showed increased STAT5 activity in renal epithelial cells, which correlated with de novo expression of cyclin D1, a STAT5 target gene. Chromatin immunoprecipitation experiments revealed that STAT5 transcriptionally activated cyclin D1 in a growth hormone-dependent fashion, thus providing a mechanism into how STAT5 enhances proliferation. Finally, we provide evidence of elevated serum growth hormone in Pkd1 mutant mice. Thus, the growth hormone/STAT5 signaling axis is a novel therapeutic target in ADPKD
Exploring the link between MORF4L1 and risk of breast cancer.
INTRODUCTION: Proteins encoded by Fanconi anemia (FA) and/or breast cancer (BrCa) susceptibility genes cooperate in a common DNA damage repair signaling pathway. To gain deeper insight into this pathway and its influence on cancer risk, we searched for novel components through protein physical interaction screens. METHODS: Protein physical interactions were screened using the yeast two-hybrid system. Co-affinity purifications and endogenous co-immunoprecipitation assays were performed to corroborate interactions. Biochemical and functional assays in human, mouse and Caenorhabditis elegans models were carried out to characterize pathway components. Thirteen FANCD2-monoubiquitinylation-positive FA cell lines excluded for genetic defects in the downstream pathway components and 300 familial BrCa patients negative for BRCA1/2 mutations were analyzed for genetic mutations. Common genetic variants were genotyped in 9,573 BRCA1/2 mutation carriers for associations with BrCa risk. RESULTS: A previously identified co-purifying protein with PALB2 was identified, MRG15 (MORF4L1 gene). Results in human, mouse and C. elegans models delineate molecular and functional relationships with BRCA2, PALB2, RAD51 and RPA1 that suggest a role for MRG15 in the repair of DNA double-strand breaks. Mrg15-deficient murine embryonic fibroblasts showed moderate sensitivity to Îł-irradiation relative to controls and reduced formation of Rad51 nuclear foci. Examination of mutants of MRG15 and BRCA2 C. elegans orthologs revealed phenocopy by accumulation of RPA-1 (human RPA1) nuclear foci and aberrant chromosomal compactions in meiotic cells. However, no alterations or mutations were identified for MRG15/MORF4L1 in unclassified FA patients and BrCa familial cases. Finally, no significant associations between common MORF4L1 variants and BrCa risk for BRCA1 or BRCA2 mutation carriers were identified: rs7164529, Ptrend = 0.45 and 0.05, P2df = 0.51 and 0.14, respectively; and rs10519219, Ptrend = 0.92 and 0.72, P2df = 0.76 and 0.07, respectively. CONCLUSIONS: While the present study expands on the role of MRG15 in the control of genomic stability, weak associations cannot be ruled out for potential low-penetrance variants at MORF4L1 and BrCa risk among BRCA2 mutation carriers.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Diagnosis and management of SilverâRussell syndrome: first international consensus statement
This Consensus Statement summarizes recommendations for clinical diagnosis, investigation and management of patients with SilverâRussell syndrome (SRS), an imprinting disorder that causes prenatal and postnatal growth retardation. Considerable overlap exists between the care of individuals born small for gestational age and those with SRS. However, many specific management issues exist and evidence from controlled trials remains limited. SRS is primarily a clinical diagnosis; however, molecular testing enables confirmation of the clinical diagnosis and defines the subtype. A 'normal' result from a molecular test does not exclude the diagnosis of SRS. The management of children with SRS requires an experienced, multidisciplinary approach. Specific issues include growth failure, severe feeding difficulties, gastrointestinal problems, hypoglycaemia, body asymmetry, scoliosis, motor and speech delay and psychosocial challenges. An early emphasis on adequate nutritional status is important, with awareness that rapid postnatal weight gain might lead to subsequent increased risk of metabolic disorders. The benefits of treating patients with SRS with growth hormone include improved body composition, motor development and appetite, reduced risk of hypoglycaemia and increased height. Clinicians should be aware of possible premature adrenarche, fairly early and rapid central puberty and insulin resistance. Treatment with gonadotropin-releasing hormone analogues can delay progression of central puberty and preserve adult height potential. Long-term follow up is essential to determine the natural history and optimal management in adulthood
Regional and national guideline recommendations for digital ano-rectal examination as a means for anal cancer screening in HIV positive men who have sex with men: a systematic review
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The contribution of X-linked coding variation to severe developmental disorders
Abstract: Over 130 X-linked genes have been robustly associated with developmental disorders, and X-linked causes have been hypothesised to underlie the higher developmental disorder rates in males. Here, we evaluate the burden of X-linked coding variation in 11,044 developmental disorder patients, and find a similar rate of X-linked causes in males and females (6.0% and 6.9%, respectively), indicating that such variants do not account for the 1.4-fold male bias. We develop an improved strategy to detect X-linked developmental disorders and identify 23 significant genes, all of which were previously known, consistent with our inference that the vast majority of the X-linked burden is in known developmental disorder-associated genes. Importantly, we estimate that, in male probands, only 13% of inherited rare missense variants in known developmental disorder-associated genes are likely to be pathogenic. Our results demonstrate that statistical analysis of large datasets can refine our understanding of modes of inheritance for individual X-linked disorders