Screening for pineal trilateral retinoblastoma revisited: a meta-analysis

Topic To determine until what age children are at risk for pineal trilateral retinoblastoma (TRb), whether its onset is linked to the age at which intraocular retinoblastomas develop, and the lead time from a detectable pineal TRb to symptoms. Clinical relevance About 45% of patients with retinoblastoma – those with a germline RB1 pathogenic variant – are at risk for pineal TRb. Early detection and treatment is essential for survival. Current evidence is unclear on the usefulness of screening for pineal TRb and, if useful, until what age screening should be continued. Methods We conducted a study according to the MOOSE guideline for reporting meta-analyses of observational studies. We searched PubMed and Embase between January 1, 1966, and February 27, 2019, for published literature. We considered articles reporting patients with TRb with survival and follow-up data. Inclusion of articles was performed separately and independently by two authors, and two authors also independently extracted the relevant data. They resolved discrepancies by consensus. Results One hundred thirty-eight patients with pineal TRb were included. Of 22 asymptomatic patients, 21 (95%) were diagnosed before the age of 40 months (median 16, interquartile range 9–29). Age at diagnosis of pineal TRb in patients diagnosed with retinoblastoma at ≤6 months versus >6 months of age were comparable (P=0.44), suggesting independency between the ages at diagnosis of intraocular retinoblastoma and pineal TRb. The laterality of intraocular retinoblastoma and its treatment were unassociated with the age when the pineal TRb was diagnosed. The lead time from an asymptomatic to a symptomatic pineal TRb was approximately 1 year. By performing a screening magnetic resonance imaging scan every 6 months after the diagnosis of heritable retinoblastoma (median age 6 months) until the age of 36 months, at least 311 and 776 scans would be required to detect one asymptomatic pineal TRb and to save one life, respectively. Conclusion Patients with retinoblastoma are at risk for pineal trilateral retinoblastoma for a shorter period than previously assumed and the age at diagnosis of pineal trilateral retinoblastoma is independent of the age at diagnosis of retinoblastoma. The GRADE level of evidence for these conclusions remains low.Peer reviewe

Asynchronous pineoblastoma is more likely after early diagnosis of retinoblastoma : a meta-analysis

Purpose To determine the risk of patients with an early diagnosis of heritable retinoblastoma being diagnosed with TRb (or pineoblastoma) asynchronously in a later stage and its effect on screening. Methods We updated the search (PubMed and Embase) for published literature as performed by our research group in 2014 and 2019. Trilateral retinoblastoma (TRb) patients were eligible for inclusion if identifiable as unique and the age at which TRb was diagnosed was available. The search yielded 97 new studies. Three new studies and eight new patients were included. Combined with 189 patients from the previous meta-analysis, the database included 197 patients. The main outcome was the percentage of asynchronous TRb in patients diagnosed before and after preset age thresholds of 6 and 12 months of age at retinoblastoma diagnosis. Results Seventy-nine per cent of patients with pineoblastoma are diagnosed with retinoblastoma before the age of 12 months. However, baseline MRI screening at time of retinoblastoma diagnosis fails to detect the later diagnosed pineal TRb in 89% of patients. We modelled that an additional MRI performed at the age of 29 months picks up 53% of pineoblastomas in an asymptomatic phase. The detection rate increased to 72%, 87% and 92%, respectively, with 2, 3 and 4 additional MRIs. Conclusions An MRI of the brain in heritable retinoblastoma before the age of 12 months misses most pineoblastomas, while retinoblastomas are diagnosed most often before the age of 12 months. Optimally timed additional MRI scans of the brain can increase the asymptomatic detection rate of pineoblastoma.Peer reviewe

Spinal involvement in mucopolysaccharidosis IVA (Morquio-Brailsford or Morquio A syndrome): presentation, diagnosis and management.

Mucopolysaccharidosis IVA (MPS IVA), also known as Morquio-Brailsford or Morquio A syndrome, is a lysosomal storage disorder caused by a deficiency of the enzyme N-acetyl-galactosamine-6-sulphate sulphatase (GALNS). MPS IVA is multisystemic but manifests primarily as a progressive skeletal dysplasia. Spinal involvement is a major cause of morbidity and mortality in MPS IVA. Early diagnosis and timely treatment of problems involving the spine are critical in preventing or arresting neurological deterioration and loss of function. This review details the spinal manifestations of MPS IVA and describes the tools used to diagnose and monitor spinal involvement. The relative utility of radiography, computed tomography (CT) and magnetic resonance imaging (MRI) for the evaluation of cervical spine instability, stenosis, and cord compression is discussed. Surgical interventions, anaesthetic considerations, and the use of neurophysiological monitoring during procedures performed under general anaesthesia are reviewed. Recommendations for regular radiological imaging and neurologic assessments are presented, and the need for a more standardized approach for evaluating and managing spinal involvement in MPS IVA is addressed

Characterisation of retinoblastomas without RB1 mutations: genomic, gene expression, and clinical studies

SummaryBackgroundRetinoblastoma is the childhood retinal cancer that defined tumour-suppressor genes. Previous work shows that mutation of both alleles of the RB1 retinoblastoma suppressor gene initiates disease. We aimed to characterise non-familial retinoblastoma tumours with no detectable RB1 mutations.MethodsOf 1068 unilateral non-familial retinoblastoma tumours, we compared those with no evidence of RB1 mutations (RB1+/+) with tumours carrying a mutation in both alleles (RB1−/−). We analysed genomic copy number, RB1 gene expression and protein function, retinal gene expression, histological features, and clinical data.FindingsNo RB1 mutations (RB1+/+) were reported in 29 (2·7%) of 1068 unilateral retinoblastoma tumours. 15 of the 29 RB1+/+ tumours had high-level MYCN oncogene amplification (28–121 copies; RB1+/+MYCNA), whereas none of 93 RB1−/− primary tumours tested showed MYCN amplification (p<0·0001). RB1+/+MYCNA tumours expressed functional RB1 protein, had fewer overall genomic copy-number changes in genes characteristic of retinoblastoma than did RB1−/− tumours, and showed distinct aggressive histological features. MYCN amplification was the sole copy-number change in one RB1+/+MYCNA retinoblastoma. One additional MYCNA tumour was discovered after the initial frequencies were determined, and this is included in further analyses. Median age at diagnosis of the 17 children with RB1+/+MYCNA tumours was 4·5 months (IQR 3·5–10), compared with 24 months (15–37) for 79 children with non-familial unilateral RB1−/− retinoblastoma.InterpretationAmplification of the MYCN oncogene might initiate retinoblastoma in the presence of non-mutated RB1 genes. These unilateral RB1+/+MYCNA retinoblastomas are characterised by distinct histological features, only a few of the genomic copy-number changes that are characteristic of retinoblastoma, and very early age of diagnosis.FundingNational Cancer Institute–National Institutes of Health, Canadian Institutes of Health Research, German Research Foundation, Canadian Retinoblastoma Society, Hyland Foundation, Toronto Netralaya and Doctors Lions Clubs, Ontario Ministry of Health and Long Term Care, UK-Essen, and Foundations Avanti-STR and KiKa

Analysis of the functional conservation of ethylene receptors between maize and Arabidopsis

Ethylene, a regulator of plant growth and development, is perceived by specific receptors that act as negative regulators of the ethylene response. Five ethylene receptors, i.e., ETR1, ERS1, EIN4, ETR2, and ERS2, are present in Arabidopsis and dominant negative mutants of each that confer ethylene insensitivity have been reported. In contrast, maize contains just two types of ethylene receptors: ZmERS1, encoded by ZmERS1a and ZmERS1b, and ZmETR2, encoded by ZmETR2a and ZmETR2b. In this study, we introduced a Cys to Tyr mutation in the transmembrane domain of ZmERS1b and ZmETR2b that is present in the etr1-1 dominant negative mutant and expressed each protein in Arabidopsis. Mutant Zmers1b and Zmetr2b receptors conferred ethylene insensitivity and Arabidopsis expressing Zmers1b or Zmetr2b were larger and exhibited a delay in leaf senescence characteristic of ethylene insensitive Arabidopsis mutants. Zmers1b and Zmetr2b were dominant and functioned equally well in a hemizygous or homozygous state. Expression of the Zmers1b N-terminal transmembrane domain was sufficient to exert dominance over endogenous Arabidopsis ethylene receptors whereas the Zmetr2b N-terminal domain failed to do so. Neither Zmers1b nor Zmetr2b functioned in the absence of subfamily 1 ethylene receptors, i.e., ETR1 and ERS1. These results suggest that Cys65 in maize ZmERS1b and ZmETR2b plays the same role that it does in Arabidopsis receptors. Moreover, the results demonstrate that the mutant maize ethylene receptors are functionally dependent on subfamily 1 ethylene receptors in Arabidopsis, indicating substantial functional conservation between maize and Arabidopsis ethylene receptors despite their sequence divergence

Multiple Deprivation, Severity and Latent Sub-Groups:Advantages of Factor Mixture Modelling for Analysing Material Deprivation

Material deprivation is represented in different forms and manifestations. Two individuals with the same deprivation score (i.e. number of deprivations), for instance, are likely to be unable to afford or access entirely or partially different sets of goods and services, while one individual may fail to purchase clothes and consumer durables and another one may lack access to healthcare and be deprived of adequate housing . As such, the number of possible patterns or combinations of multiple deprivation become increasingly complex for a higher number of indicators. Given this difficulty, there is interest in poverty research in understanding multiple deprivation, as this analysis might lead to the identification of meaningful population sub-groups that could be the subjects of specific policies. This article applies a factor mixture model (FMM) to a real dataset and discusses its conceptual and empirical advantages and disadvantages with respect to other methods that have been used in poverty research . The exercise suggests that FMM is based on more sensible assumptions (i.e. deprivation covary within each class), provides valuable information with which to understand multiple deprivation and is useful to understand severity of deprivation and the additive properties of deprivation indicators

Continuity and change in the institution of town and country planning: modelling the role of ideology

The institution of town and country planning rests upon ideas and concepts which will always be contested. Such concepts include ‘liberty’, ‘community’, ‘society’ and ‘the state’. It is a function of political ideology to seek to fix the meanings of contested concepts and thus exert control over political reality. By analysing the particular conceptual structure of the ideologies which seek to influence planning from positions of political power, the analyst can show how these ideologies are related to shifts in the conceptual and institutional structure of planning. The paper illustrates this analytical method in the context of the transition from the ideology of New Labour to the ideology of the Conservative-led Coalition government in England after 2010

Determinants of Initiation Codon Selection during Translation in Mammalian Cells

Factors affecting translation of mRNA contribute to the complexity of eukaryotic proteomes. In some cases, translation of a particular mRNA can generate multiple proteins. However, the factors that determine whether ribosomes initiate translation from the first AUG codon in the transcript, from a downstream codon, or from multiple sites are not completely understood. Various mRNA properties, including AUG codon-accessibility and 5′ leader length have been proposed as potential determinants that affect where ribosomes initiate translation. To explore this issue, we performed studies using synthetic mRNAs with two in-frame AUG codons−both in excellent context. Open reading frames initiating at AUG1 and AUG2 encode large and small isoforms of a reporter protein, respectively. Translation of such an mRNA in COS-7 cells was shown to be 5′ cap-dependent and to occur efficiently from both AUG codons. AUG codon-accessibility was modified by using two different elements: an antisense locked nucleic acid oligonucleotide and an exon-junction complex. When either element was used to mask AUG1, the ratio of the proteins synthesized changed, favoring the smaller (AUG2-initiated) protein. In addition, we observed that increased leader length by itself changed the ratio of the proteins and favored initiation at AUG1. These observations demonstrate that initiation codon selection is affected by various factors, including AUG codon-accessibility and 5′ leader length, and is not necessarily determined by the order of AUG codons (5′→3′). The modulation of AUG codon accessibility may provide a powerful means of translation regulation in eukaryotic cells

The identification of genes important in pseudomonas syringae pv. phaseolicola plant colonisation using in vitro screening of transposon libraries

The bacterial plant pathogen Pseudomonas syringae pv. phaseolicola (Pph) colonises the surface of common bean plants before moving into the interior of plant tissue, via wounds and stomata. In the intercellular spaces the pathogen proliferates in the apoplastic fluid and forms microcolonies (biofilms) around plant cells. If the pathogen can suppress the plant’s natural resistance response, it will cause halo blight disease. The process of resistance suppression is fairly well understood, but the mechanisms used by the pathogen in colonisation are less clear. We hypothesised that we could apply in vitro genetic screens to look for changes in motility, colony formation, and adhesion, which are proxies for infection, microcolony formation and cell adhesion. We made transposon (Tn) mutant libraries of Pph strains 1448A and 1302A and found 106/1920 mutants exhibited alterations in colony morphology, motility and biofilm formation. Identification of the insertion point of the Tn identified within the genome highlighted, as expected, a number of altered motility mutants bearing mutations in genes encoding various parts of the flagellum. Genes involved in nutrient biosynthesis, membrane associated proteins, and a number of conserved hypothetical protein (CHP) genes were also identified. A mutation of one CHP gene caused a positive increase in in planta bacterial growth. This rapid and inexpensive screening method allows the discovery of genes important for in vitro traits that can be correlated to roles in the plant interactio