Obstetrics and Gynaecology - Research Publications
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ItemPLZF Mediates the PTEN/AKT/FOXO3a Signaling in Suppression of Prostate Tumorigenesis(PUBLIC LIBRARY SCIENCE, 2013-12-10)Promyelocytic leukemia zinc finger (PLZF) protein expression is closely related to the progression of human cancers, including prostate cancer (PCa). However, the according context of a signaling pathway for PLZF to suppress prostate tumorigenesis remains greatly unknown. Here we report that PLZF is a downstream mediator of the PTEN signaling pathway in PCa. We found that PLZF expression is closely correlated with PTEN expression in a cohort of prostate cancer specimens. Interestingly, both PTEN rescue and phosphoinositide 3-kinase (PI3K) inhibitor LY294002 treatment increase the PLZF expression in prostate cancer cell lines. Further, luciferase reporter assay and chromatin immunoprecipitation assay demonstrate that FOXO3a, a transcriptional factor phosphorylated by PI3K/AKT, could directly bind to the promoter of PLZF gene. These results indicate that PTEN regulates PLZF expression by AKT/FOXO3a. Moreover, our animal experiments also demonstrate that PLZF is capable of inhibiting prostate tumorigenesis in vivo. Taken together, our study defines a PTEN/PLZF pathway and would shed new lights for developing therapeutic strategy of prostate cancer.
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ItemPatient-derived xenograft models to improve targeted therapy in epithelial ovarian cancer treatment(FRONTIERS MEDIA SA, 2013)Despite increasing evidence that precision therapy targeted to the molecular drivers of a cancer has the potential to improve clinical outcomes, high-grade epithelial ovarian cancer (OC) patients are currently treated without consideration of molecular phenotype, and predictive biomarkers that could better inform treatment remain unknown. Delivery of precision therapy requires improved integration of laboratory-based models and cutting-edge clinical research, with pre-clinical models predicting patient subsets that will benefit from a particular targeted therapeutic. Patient-derived xenografts (PDXs) are renewable tumor models engrafted in mice, generated from fresh human tumors without prior in vitro exposure. PDX models allow an invaluable assessment of tumor evolution and adaptive response to therapy. PDX models have been applied to pre-clinical drug testing and biomarker identification in a number of cancers including ovarian, pancreatic, breast, and prostate cancers. These models have been shown to be biologically stable and accurately reflect the patient tumor with regards to histopathology, gene expression, genetic mutations, and therapeutic response. However, pre-clinical analyses of molecularly annotated PDX models derived from high-grade serous ovarian cancer (HG-SOC) remain limited. In vivo response to conventional and/or targeted therapeutics has only been described for very small numbers of individual HG-SOC PDX in conjunction with sparse molecular annotation and patient outcome data. Recently, two consecutive panels of epithelial OC PDX correlate in vivo platinum response with molecular aberrations and source patient clinical outcomes. These studies underpin the value of PDX models to better direct chemotherapy and predict response to targeted therapy. Tumor heterogeneity, before and following treatment, as well as the importance of multiple molecular aberrations per individual tumor underscore some of the important issues addressed in PDX models.
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ItemVariation in severe maternal morbidity according to socioeconomic position: a UK national case-control study(BMJ PUBLISHING GROUP, 2013)OBJECTIVES: This study aimed to explore the independent association between socioeconomic position, defined by occupation, and severe maternal morbidity among women in the UK. DESIGN: Case-control study. SETTING: The analysis was conducted as a case-control analysis, using data from a series of studies of direct causes of severe maternal morbidity undertaken through the UK Obstetric Surveillance System (UKOSS), with data collected throughout all consultant-let obstetric units in the UK. PARTICIPANTS: The analysis included 1144 cases and 2256 comparison women (controls). UKOSS studies from which data on case women were obtained included amniotic fluid embolism, acute fatty liver of pregnancy, eclampsia, peripartum hysterectomy, therapies for peripartum haemorrhage and uterine rupture. PRIMARY OUTCOME MEASURE: Odds of severe maternal morbidity by socioeconomic group, independent of ethnicity, maternal age, smoking, pre-existing medical condition, body mass index (BMI), multiple pregnancy and past pregnancy complications. Occupation was used to classify different socioeconomic groups. SECONDARY OUTCOME MEASURE: Odds of morbidity related to ethnic group, maternal age, smoking, pre-existing medical condition, BMI, multiple pregnancy and past pregnancy complications. RESULTS: Across the socioeconomic groups, compared with the 'managerial/professional' group, adjusted ORs were 1.17 (95% CI 0.94 to 1.45) for the 'intermediate group', 1.16 (95% CI 0.93 to 1.45) for 'routine/manual', 1.22 (95% CI 0.92 to 1.61) for 'unemployed' women and 1.51 (95% CI 1.18 to 1.94) for women with missing socioeconomic information. Women of non-white ethnicity, older maternal age (≥35 years), BMI ≥25 kg/m(2) and those with pre-existing medical condition/s, multiple pregnancy or past pregnancy complications were shown to have a significantly increased odds of severe maternal morbidity. CONCLUSIONS: This study suggests that socioeconomic position may be independently associated with an increased risk of severe maternal morbidity, although the observed association was not statistically significant. Further research is warranted to confirm this and investigate why this association might exist in a country where healthcare is universal and free at the point of access.
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ItemHypothenar hammer syndrome: case report and literature review.(Georg Thieme Verlag KG, 2013)Case report of a 69 year-old patient, with history of repetitive trauma events in the wrist, clinically simulating tenosynovitis, being held with Doppler Ultrasound and Magnetic Nuclear Resonance, which showed ulnar artery thrombosis. The accurate diagnosis of the hammer hypothenar disease through those tests enable an early intervention, improving the prognosis of patients affected by this rare disease.
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ItemNo Preview AvailableMedical retrieval and needs of infants with bronchiolitis: An analysis by gestational age(WILEY, 2013-03)AIM: Viral bronchiolitis is the most common lower respiratory tract infection in children less than 12 months of age. Prematurity is an independent risk factor for disease severity. Many infected infants require hospitalisation and those living in regional centres frequently require transfer to metropolitan hospitals capable of providing assisted ventilation. METHOD: We reviewed infants with bronchiolitis transported by the Victorian Newborn Emergency Transport Service between January 2003 and June 2007. We compared the clinical presentation and treatment required by infants born preterm with those of their term counterparts. RESULTS: Of the 192 infants transported, 92 were born preterm. Preterm infants were younger at time of transport (mean post-menstrual age 41 weeks vs. 45 weeks) and were more likely to require invasive ventilation (60% vs. 32%, P < 0.001) and to receive a fluid bolus (47% vs. 34%, P = 0.04) when compared with infants who had been born at term. Apnoea, either as a presenting symptom or in combination with respiratory distress, was more common in the preterm group (70% vs. 36%, P < 0.001). CONCLUSION: Higher illness severity should be anticipated in ex-preterm infants who present with bronchiolitis. Preterm infants with bronchiolitis are more likely to require invasive ventilation and fluid resuscitation than term infants, suggesting the need for a lower threshold for referral and medical retrieval.
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ItemContribution of Brain Size to IQ and Educational Underperformance in Extremely Preterm Adolescents(PUBLIC LIBRARY SCIENCE, 2013-10-09)OBJECTIVES: Extremely preterm (EP) survivors have smaller brains, lower IQ, and worse educational achievement than their term-born peers. The contribution of smaller brain size to the IQ and educational disadvantages of EP is unknown. This study aimed (i) to compare brain volumes from multiple brain tissues and structures between EP-born (< 28 weeks) and term-born (≥ 37 weeks) control adolescents, (ii) to explore the relationships of brain tissue volumes with IQ and basic educational skills and whether this differed by group, and (iii) to explore how much total brain tissue volume explains the underperformance of EP adolescents compared with controls. METHODS: Longitudinal cohort study of 148 EP and 132 term controls born in Victoria, Australia in 1991-92. At age 18, magnetic resonance imaging-determined brain volumes of multiple tissues and structures were calculated. IQ and educational skills were measured using the Wechsler Abbreviated Scale of Intelligence (WASI) and the Wide Range Achievement Test(WRAT-4), respectively. RESULTS: Brain volumes were smaller in EP adolescents compared with controls (mean difference [95% confidence interval] of -5.9% [-8.0, -3.7%] for total brain tissue volume). The largest relative differences were noted in the thalamus and hippocampus. The EP group had lower IQs(-11.9 [-15.4, -8.5]), spelling(-8.0 [-11.5, -4.6]), math computation(-10.3 [-13.7, -6.9]) and word reading(-5.6 [-8.8, -2.4]) scores than controls; all p-values<0.001. Volumes of total brain tissue and other brain tissues and structures correlated positively with IQ and educational skills, a relationship that was similar for both the EP and controls. Total brain tissue volume explained between 20-40% of the IQ and educational outcome differences between EP and controls. CONCLUSIONS: EP adolescents had smaller brain volumes, lower IQs and poorer educational performance than controls. Brain volumes of multiple tissues and structures are related to IQ and educational outcomes. Smaller total brain tissue volume is an important contributor to the cognitive and educational underperformance of adolescents born EP.
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ItemEpimedium Flavonoids Counteract the Side Effects of Glucocorticoids on Hypothalamic-Pituitary-Adrenal Axis(HINDAWI LTD, 2013)Our previous studies demonstrated that the epimedium herb, when simultaneously used with GCs, counteracted suppressive effects of GCs on the HPA axis without adverse influence on the therapeutic action of GCs. Here, total flavones were extracted from the epimedium flavonoids (EFs) and then used to investigate whether EFs provide protective effects on the HPA axis. We found that GCs induced a significant decrease in body weight gain, adrenal gland weight gain, and plasma adrenocorticotropin (ACTH) and corticosterone levels. After treatment with EFs, body weight gain, adrenal gland weight gain, and plasma corticosterone level were significantly restored, whilst plasma ACTH level was partially elevated. EFs were also shown to promote cell proliferation in the outer layer of adrenal cortex and to enhance the migration of newly divided cells toward the inner layer. To elucidate the underlying mechanisms, the mRNA expression of insulin-like growth factor II (IGF-II) was measured, and EFs significantly upregulated IGF-II expression. Our results indicated that EFs counteract the suppression of the HPA axis induced by GCs. This may involve both the ACTH and IGF-II pathways and thereby promote regeneration of the adrenal cortex suggesting a potential clinical application of EFs against the suppressive effects of GCs on the HPA axis.
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ItemThe Potential of Metatranscriptomics for Identifying Screening Targets for Bacterial Vaginosis(PUBLIC LIBRARY SCIENCE, 2013-09-27)BACKGROUND: The ribosomal RNA content of a sample collected from a woman with bacterial vaginosis (BV) was analysed to determine the active microbial community, and to identify potential targets for further screening. METHODOLOGY/PRINCIPAL FINDINGS: The sample from the BV patient underwent total RNA extraction, followed by physical subtraction of human rRNA and whole transcriptome amplification. The metatranscriptome was sequenced using Roche 454 titanium chemistry. The bioinformatics pipeline MG-RAST and desktop DNA analysis platforms were utilised to analyse results. Bacteria of the genus Prevotella (predominately P. amnii) constituted 36% of the 16S rRNA reads, followed by Megasphaera (19%), Leptotrichia/Sneathia (8%) and Fusobacterium (8%). Comparison of the abundances of several bacteria to quantitative PCR (qPCR) screening of extracted DNA revealed comparable relative abundances. This suggests a correlation between what was present and transcriptionally active in this sample: however distinct differences were seen when compared to the microbiome determined by 16S rRNA gene amplicon sequencing. To assess the presence of P. amnii in a larger pool of samples, 90 sexually active women were screened using qPCR. This bacterium was found to be strongly associated with BV (P<0.001, OR 23.3 (95%CI:2.9-190.7)) among the 90 women. CONCLUSIONS/SIGNIFICANCE: This study highlighted the potential of metatranscriptomics as a tool for characterising metabolically active microbiota and identifying targets for further screening. Prevotella amnii was chosen as an example target, being the most metabolically active species present in the single patient with BV, and was found to be detected at a high concentration by qPCR in 31% of cohort with BV, with an association with both oral and penile-vaginal sex.
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ItemCell-Type-Specific Transcriptional Profiles of the Dimorphic Pathogen Penicillium marneffei Reflect Distinct Reproductive, Morphological, and Environmental Demands(OXFORD UNIV PRESS INC, 2013-11)Penicillium marneffei is an opportunistic human pathogen endemic to Southeast Asia. At 25° P. marneffei grows in a filamentous hyphal form and can undergo asexual development (conidiation) to produce spores (conidia), the infectious agent. At 37° P. marneffei grows in the pathogenic yeast cell form that replicates by fission. Switching between these growth forms, known as dimorphic switching, is dependent on temperature. To understand the process of dimorphic switching and the physiological capacity of the different cell types, two microarray-based profiling experiments covering approximately 42% of the genome were performed. The first experiment compared cells from the hyphal, yeast, and conidiation phases to identify "phase or cell-state-specific" gene expression. The second experiment examined gene expression during the dimorphic switch from one morphological state to another. The data identified a variety of differentially expressed genes that have been organized into metabolic clusters based on predicted function and expression patterns. In particular, C-14 sterol reductase-encoding gene ergM of the ergosterol biosynthesis pathway showed high-level expression throughout yeast morphogenesis compared to hyphal. Deletion of ergM resulted in severe growth defects with increased sensitivity to azole-type antifungal agents but not amphotericin B. The data defined gene classes based on spatio-temporal expression such as those expressed early in the dimorphic switch but not in the terminal cell types and those expressed late. Such classifications have been helpful in linking a given gene of interest to its expression pattern throughout the P. marneffei dimorphic life cycle and its likely role in pathogenicity.
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ItemPhase II single arm open label multicentre clinical trial to evaluate the efficacy and side effects of a combination of gefitinib and methotrexate to treat tubal ectopic pregnancies (GEM II): study protocol(BMJ PUBLISHING GROUP, 2013)INTRODUCTION: Tubal ectopic pregnancy (tEP) is the most common life-threatening condition in gynaecology. tEPs with pretreatment serum human chorionic gonadotrophin (hCG) levels <1000 IU/L respond well to outpatient medical treatment with intramuscular methotrexate (MTX). TEPs with hCG >1000 IU/L take a significant time to resolve with MTX and require multiple outpatient monitoring visits. Gefitinib is an orally active epidermal growth factor receptor (EGFR) antagonist. In preclinical studies, we found that EP implantation sites express high levels of EGFR and that gefitinib augments MTX-induced regression of pregnancy-like tissue. We performed a phase I toxicity study administering oral gefitinib and intramuscular MTX to 12 women with tEPs. The combination therapy did not cause significant toxicities and was well tolerated. We noted that combination therapy resolved the tEPs faster than MTX alone. We now describe the protocol of a larger single arm trial to estimate the efficacy and side effects of combination gefitinib and MTX to treat stable tEPs with hCG 1000-10 000 IU/L METHODS AND ANALYSIS: We propose to undertake a single-arm multicentre open label trial (in Edinburgh and Melbourne) and recruit 28 women with tEPs (pretreatment serum hCG 1000-10 000 IU/L). We intend to give a single dose of intramuscular MTX (50 mg/m(2)) and oral gefitinib (250 mg) daily for 7 days. Our primary outcome is the resolution of EP to non-pregnant hCG levels <15 IU/L without requirement of surgery. Our secondary outcomes are comparison of time to resolution against historical controls given MTX only, and safety and tolerability as determined by clinical/biochemical assessment. ETHICS AND DISSEMINATION: Ethical approval has been obtained from Scotland A Research Ethics Committee (MREC 11/AL/0350), Southern Health Human Research Ethics Committee B (HREC 11180B) and the Mercy Health Human Research Ethics Committee (R12/25). Data will be presented at international conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ACTRN12611001056987.