51 research outputs found
Rapid ovarian transcript changes during the onset of premature ovarian insufficiency in a mouse model
Premature ovarian insufficiency (POI) affects 1-3% of women under 40 years of age. The identified causes are highly heterogeneous, and 70% of the cases are idiopathic. The ovarian manifestation varies from a variable population of follicles that fail to develop (follicular POI) to the absence of follicles (afollicular POI) with a transition from one to the other over time. Previously, we have described a mouse model of POI that results from an oocyte-specific deletion of N- and O-glycans; Double Mutant (DM). DM females produce only one litter before undergoing POI due to ovarian dysfunction. In this study, we have characterised the gene expression profile of prepuberal (3 weeks), fertile (6 weeks) and infertile (9 weeks) DM ovaries. Up-regulation of cathepsin K (Ctsk, with unknown ovarian function) seems to trigger transcriptional changes in DM ovaries. Significant transcriptional changes then occur rapidly, associated with morphophysiological changes displayed by DM mice throughout the onset of POI. We identified genetic pathways such as extracellular matrix and immune response as candidates for the onset of POI in DM females. Remarkably, DM mice and POI women share a set of differentially expressed genes, including a functionally and co-expressed network of Mcm (minichromosome maintenance proteins) family members. The transcriptomic profile of the DM mouse model provides novel insight into the aetiology of POI
Apparently synonymous substitutions in FGFR2 affect splicing and result in mild Crouzon syndrome
Background: Mutations of fibroblast growth factor receptor 2 (FGFR2) account for a higher proportion of genetic cases of craniosynostosis than any other gene, and are associated with a wide spectrum of severity of clinical problems. Many of these mutations are highly recurrent and their associated features well documented. Crouzon syndrome is typically caused by heterozygous missense mutations in the third immunoglobulin domain of FGFR2.Case presentation: Here we describe two families, each segregating a different, previously unreported FGFR2 mutation of the same nucleotide, c.1083A>G and c.1083A>T, both of which encode an apparently synonymous change at the Pro361 codon. We provide experimental evidence that these mutations affect normal FGFR2 splicing and document the clinical consequences, which include a mild Crouzon syndrome phenotype and reduced penetrance of craniosynostosis.Conclusions: These observations add to a growing list of FGFR2 mutations that affect splicing and provide important clinical information for genetic counselling of families affected by these specific mutations
Diagnostic value of exome and whole genome sequencing in craniosynostosis
Background Craniosynostosis, the premature fusion of one or more cranial sutures, occurs in ~1 in 2250 births, either in isolation or as part of a syndrome. Mutations in at least 57 genes have been associated with craniosynostosis, but only a minority of these are included in routine laboratory genetic testing. Methods We used exome or whole genome sequencing to seek a genetic cause in a cohort of 40 subjects with craniosynostosis, selected by clinical or molecular geneticists as being high-priority cases, and in whom prior clinically driven genetic testing had been negative. Results We identified likely associated mutations in 15 patients (37.5%), involving 14 different genes. All genes were mutated in single families, except for IL11RA (two families). We classified the other positive diagnoses as follows: commonly mutated craniosynostosis genes with atypical presentation (EFNB1, TWIST1); other core craniosynostosis genes (CDC45, MSX2, ZIC1); genes for which mutations are only rarely associated with craniosynostosis (FBN1, HUWE1, KRAS, STAT3); and known disease genes for which a causal relationship with craniosynostosis is currently unknown (AHDC1, NTRK2). In two further families, likely novel disease genes are currently undergoing functional validation. In 5 of the 15 positive cases, the (previously unanticipated) molecular diagnosis had immediate, actionable consequences for either genetic or medical management (mutations in EFNB1, FBN1, KRAS, NTRK2, STAT3). Conclusions This substantial genetic heterogeneity, and the multiple actionable mutations identified, emphasises the benefits of exome/whole genome sequencing to identify causal mutations in craniosynostosis cases for which routine clinical testing has yielded negative results
Amphibians and reptiles from a highly diverse area of the Caatinga domain: composition and conservation implications
Bevacizumab, Irinotecan, or Topotecan Added to Temozolomide for Children With Relapsed and Refractory Neuroblastoma: Results of the ITCC-SIOPEN BEACON-Neuroblastoma Trial
Purpose
Outcomes for children with relapsed and refractory high-risk neuroblastoma (RR-HRNB) remain dismal. The BEACON Neuroblastoma trial (EudraCT 2012-000072-42) evaluated three backbone chemotherapy regimens and the addition of the antiangiogenic agent bevacizumab (B).
Materials and Methods
Patients age 1-21 years with RR-HRNB with adequate organ function and performance status were randomly assigned in a 3 × 2 factorial design to temozolomide (T), irinotecan-temozolomide (IT), or topotecan-temozolomide (TTo) with or without B. The primary end point was best overall response (complete or partial) rate (ORR) during the first six courses, by RECIST or International Neuroblastoma Response Criteria for patients with measurable or evaluable disease, respectively. Safety, progression-free survival (PFS), and overall survival (OS) time were secondary end points.
Results
One hundred sixty patients with RR-HRNB were included. For B random assignment (n = 160), the ORR was 26% (95% CI, 17 to 37) with B and 18% (95% CI, 10 to 28) without B (risk ratio [RR], 1.52 [95% CI, 0.83 to 2.77]; P = .17). Adjusted hazard ratio for PFS and OS were 0.89 (95% CI, 0.63 to 1.27) and 1.01 (95% CI, 0.70 to 1.45), respectively. For irinotecan ([I]; n = 121) and topotecan (n = 60) random assignments, RRs for ORR were 0.94 and 1.22, respectively. A potential interaction between I and B was identified. For patients in the bevacizumab-irinotecan-temozolomide (BIT) arm, the ORR was 23% (95% CI, 10 to 42), and the 1-year PFS estimate was 0.67 (95% CI, 0.47 to 0.80).
Conclusion
The addition of B met protocol-defined success criteria for ORR and appeared to improve PFS. Within this phase II trial, BIT showed signals of antitumor activity with acceptable tolerability. Future trials will confirm these results in the chemoimmunotherapy era
Prevalence of Salmonella in fecal samples of western grey kangaroos (Macropus fuliginosus)
This is the first extensive study of the prevalence of naturally acquired Salmonella infection in wild-caught kangaroos in Australia. Given the close association between kangaroos, livestock, and humans and the growing popularity of kangaroo meat, it is important to identify epidemiologic factors associated with infection in these marsupials in order to minimize the risk of Salmonella transmission. The overall prevalence of fecal Salmonella in 645 western grey kangaroos (Macropus fuliginosus) sampled across 10 locations in Western Australia was 3.6% (95% CI: 2.3–5.3). Seven Salmonella serovars were identified including Salmonella enterica serovar Muenchen, Kiambu, Rubislaw, Lindern, Champaign, Saintpaul and II 42:g,t:-. Prevalence was significantly associated with rainfall (P<0.05) and was highest in the April–June quarter (P<0.05). There was no association between age or sex and the prevalence of Salmonella in fecal samples. Our results suggest that, while kangaroos are infected with Salmonella in their natural habitat, infection is less common than in hand-reared joeys, pet kangaroos, and macropods raised in captivity. Care should be taken to maintain hygiene during the evisceration, processing, and handling of kangaroos and to adequately cook kangaroo meat prior to consumption to reduce the risk of salmonellosis
A survey of Western Australian sheep, cattle and kangaroos to determine the prevalence of Coxiella burnetii
The objective of this study was to investigate the prevalence of Coxiella burnetii in two domestic ruminant species (cattle and sheep) and the western grey kangaroo (Macropus fuliginosus) in Western Australia (WA). The IDEXX CHEKiT Q Fever ELISA and CFT were used to test sera from 50 sheep and 329 head of cattle for anti- C. burnetii antibodies and 343 kangaroo sera were tested using an indirect ELISA developed specifically for this study. Faecal or urine samples collected from the same animals were tested with two PCR assays to identify active shedding of C. burnetii in excreta. Only two of the 379 ruminant sera had detectable levels of anti- C. burnetii antibodies according to the ELISA while the CFT did not detect any positive samples. In contrast 115 of the 343 western grey kangaroo serum samples were positive when tested with the antibody-ELISA. The first qPCR assay, targeting the IS1111a element, identified 41 of 379 ruminant and 42 of 343 kangaroo DNA samples as positive for C. burnetii DNA. The second qPCR, targeting the JB153-3 gene, identified nine C. burnetii DNA-positive ruminant samples and six positive kangaroo samples. Sequence comparisons showed high degrees of identity with C. burnetii. Isolation of C. burnetii from faeces was also attempted but was not successful. From the results presented here it appears that domestic ruminants may not be the most significant reservoir of C. burnetii in WA and that kangaroos may pose a significant threat for zoonotic transfer of this pathogen
Prevalence of Coxiella burnatii in western grey kangaroos (Macropus fuliginosus) in Western Australia
We investigated the role of the western grey kangaroo (Macropus fuliginosus) in the maintenance and transmission of Coxiella burnetti in Western Australia. Sera from 1,017 kangaroos were tested using an indirect enzyme-linked immunosorbent assay (ELISA) for the presence of C. burnetii antibodies. The overall antibody prevalence across 12 locations throughout mid- to southwestern Western Australia was 24.1% (95% CI: 21.6-26.8). Feces from 990 of the same animals were tested using PCR to identify active shedding of C. burnetii in excreta. Coxiella burnetii DNA was detected in 4.1% (95% CI: 3.1-5.6) of samples. Our results suggest that kangaroos are reservoirs for C. burnetti in Western Australia and may contribute to transmission of the organism to domestic livestock and humans
Models of cartilage vascularisation : the vasculature and its effects on developing and osteoarthritic cartilage
The vascularisation of cartilage, despite its importance in development and a number of disease processes has yet to be fully elucidated. The work presented here lends evidence for a major role for the vasculature in the erosion of cartilage. A soluble factor or factors produced by the endothelium is responsible for the degeneration and subsequent death of hypertrophic chondrocytes. The cartilage itself, however, may also have a role, as it is also shown that only a particular subset of hypertrophic chondrocytes can become invaded by the vasculature, and only at a specific time when placed on the chick chorio-allantoic membrane (CAM). Evidence is provided that the control of this may be periosteally derived, and further evidence suggests that the breakdown of cartilage hyaluronan may be an initiating factor in the process.;The collagen expression of the degenerate chondrocytes is not adversely affected qualitatively by the endothelium, except for a loss of type X collagen, though quantitatively, there is a large reduction in the amount of collagen produced. Of importance, is that throughout the degeneration process, and despite the loss of chondrocyte morphology, the cells maintain expression of type II collagen and there is no specific switch to type I collagen production that is associated with some morphological changes in chondrocytes The ultimate fate of these chondrocytes could not be convincingly elucidated.;Finally, the vascularisation of human OA cartilage was studied. Human OA cartilage loses its ability to remain avascular when placed into an in-vivo model of vascularisation, the chick CAM. The vascular invasion is associated with a loss of histochemical staining for proteoglycans and glycosaminoglycans and a deposition of type I and type X collagens around the invasive vessel
The seroprevalence and factors associated with Ross River Virus infection in western grey kangaroos (Macropus fuliginosus) in Western Australia
A serosurvey was undertaken in 15 locations in the midwest to southwest of Western Australia (WA) to investigate the seroprevalence of Ross River virus (RRV) neutralizing antibodies and factors associated with infection in western grey kangaroos (Macropus fuliginosus). The estimated seroprevalence in 2632 kangaroo samples, using a serum neutralization test, was 43.9% (95% CI 42.0, 45.8). Location was significantly associated with seroprevalence (p0.05). The results of this study indicate that kangaroos in WA are regularly infected with RRV and may be involved in the maintenance and transmission of RRV
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