Navigating physical activity engagement following a diagnosis of cancer: A qualitative exploration.

This qualitative descriptive study explored cancer survivors' experiences of barriers and facilitators to undertaking physical activity to inform how services and professionals might offer better support. Purposive and theoretical sampling was used to recruit 25 people who were up to 5 years post-cancer diagnosis. Participants took part in face to face, semi-structured interviews, and transcripts were analysed using thematic analysis. The analysis identified five interrelated themes which represented cancer survivors' views: 1) You're on your own-a sense of abandonment post-treatment, and lack of sufficient and tailored information; 2) Dis-ease-disruption to self and identity, and a heightened awareness of physical self and fragility; 3) Becoming acclimatised-physical activity in the face of treatment-related side effects and residual impairment; 4) Importance of others-encouragement and support from health professionals, family and friends, and cancer-specific exercise groups; 5) Meanings people ascribed to physical activity-these were central and could help or hinder engagement. Our findings suggest being able to live well and re-engage in meaningful activities following a diagnosis of cancer is both complex and challenging. There appear to be gaps in current service provision in supporting the broader health and well-being of cancer survivors.

The effect of colostrum storage conditions on dairy heifer calf serum immunoglobulin G concentration and preweaning health and growth rate.

The objective of the present study was to compare serum IgG concentration, weight gain, and health characteristics in Irish spring-born dairy calves fed colostrum stored using a range of conditions. Immediately after birth, 75 dairy heifer calves were assigned to 1 of 5 experimental colostrum treatments: (1) fresh pasteurized colostrum, fed immediately after pasteurization; (2) fresh colostrum, fed immediately after collection but not pasteurized; (3) colostrum stored unpasteurized at 4°C in a temperature-controlled unit for 2d before being fed to calves; (4) colostrum stored unpasteurized at 13°C in a temperature-controlled unit for 2d before being fed to calves; and (5) colostrum stored unpasteurized at 22°C in a temperature-controlled unit for 2d before being fed to calves. All colostrum had IgG concentrations >50g/L and was fed to calves promptly after birth. Blood samples were obtained from calves via the jugular vein at 0h (before colostrum feeding) and at 24h of age to determine the rate of passive transfer of IgG; individual calf live-weights were recorded to monitor weight gain (kg/d) from birth to weaning. Colostrum stored in warmer conditions (i.e., 22°C) had >42 times more bacteria present and a pH that was 0.85 units lower and resulted in a serum IgG concentration that was almost 2 times lower compared with colostrum that was pasteurized, untreated, or stored at 4°C for 2d. Colostrum stored at 4°C for 2d had more bacteria present than pasteurized and fresh colostrum but did not result in reduced calf serum IgG concentrations. Average daily weight gain from birth to weaning did not differ among treatments. Even if colostrum has sufficient IgG (>50g/L) but cannot be fed to calves when freshly collected, storage at ≤4°C for 2d is advisable to ensure adequate passive transfer when it is consumed by the calf.

Short communication: The effect of storage conditions over time on bovine colostral immunoglobulin G concentration, bacteria, and pH.

The objective of the present study was to measure the effect of storing colostrum in different conditions for varying amounts of time on IgG concentration, bacteria, and pH. In experiment 1, colostrum from 12 Holstein-Friesian cows (6 primiparous and 6 multiparous) was collected within 3h of calving, and colostrum from another 12 multiparous cows was collected within 3h of calving (6 cows) and >9h postpartum (6 cows). Aliquots were refrigerated or stored at room temperature for up to 72h, depending on treatment. In experiment 2, colostrum was collected from 6 multiparous cows within 9h of calving, and aliquots were stored for up to 72h in temperature-controlled units set at 4, 13, and 20°C. All colostrum samples were analyzed for IgG concentration, total bacteria count, and pH after 0, 6, 12, 24, 36, 48, 60, and 72h of storage. Storage conditions did not affect the IgG concentration of colostrum. Bacterial growth was most rapid in the first 6h of storage, reducing thereafter, but bacteria multiplied at a significantly greater rate when stored in warmer conditions (i.e., >4°C). The pH of colostrum was not significantly altered when stored at temperatures <13°C, but when stored at 20°C the pH significantly decreased after 24h of storage. Storing colostrum in warmer conditions significantly alters both total bacteria count and pH; consequently, colostrum should be stored at ≤4°C.

Energetic and Metabolic Power Demands of National Rugby League Match-Play.

The purpose of this study was to apply a time-motion model to estimate and describe the energy expenditure and metabolic power demands of playing positions in elite rugby league match-play, utilizing Global Positioning System (GPS) devices. 18 elite rugby league players participated in this study. Players' positional groups included: outside backs (n=59 files, n=4 players), adjustables (n=74 files, n=4 players), wide-running (n=104 files, n=7 players) and hit-up forwards (n=36 files, n=3 players). Outside backs expended the greatest total energy (40.1±5.0 kJ·kg(-1)) per match, equivalent to 8.1%, 26.6% and 61.9% greater energy than adjustables, wide-running and hit-up forwards, respectively. Adjustables attained an anaerobic index 7.3% higher than wide-running forwards, 19.7% higher than hit-up forwards (p=0.001) and 43.2% higher than outside backs (p<0.001). Wide-running forwards achieved an anaerobic index (0.34±0.04) 11% and 32.8% higher than hit-up forwards (p=0.001) and outside backs (p<0.001), respectively. Mean power of adjustables (10.0±0.9 W·kg(-1)) was significantly higher than all other groups (outside backs: 28.8%, 7.8±1.0; hit-up: 12.4%, 8.9±0.6; and wide-running: 8.7%, 9.2±0.7 forwards) (p<0.001). Energetics indices indicated differing metabolic demands for all positional groups, suggesting position-specific conditioning drills are required to replicate the energetic demands of match-play.

Severe acute disseminated encephalomyelitis: a paediatric intensive care population-based study.

There is a paucity of literature on the epidemiology of severe acute disseminated encephalomyelitis (ADEM). We describe a Paediatric Intensive Care Unit (PICU) population-based study to determine the epidemiology and clinical characteristics of children with ADEM requiring PICU admission or resulting in death. Anonymized data from the Paediatric Intensive Care Audit Network (PICANet) were obtained for all children under 16 years with a diagnosis of ADEM admitted to 25 PICUs in England and Wales (2004-2008). The Office for National Statistics (ONS) mortality database was also searched. In total, 27 PICANet cases (13 females:14 males; median age 4.8 years) were ascertained and all were alive on discharge. In addition, three cases were identified from the ONS mortality database. Of the 27 PICANet cases, clinical features included; seizures (n = 5); upper airway respiratory obstruction/stridor (n = 2); unspecified encephalopathy (n = 27); and polyfocal neurological deficits (n = 6). The median duration of ventilation was 3 days. Inotropic support was required in 4/27 patients, and one patient had invasive intracranial pressure monitoring. None received plasmapheresis. We conclude that the incidence of childhood ADEM admitted to the PICU in England and Wales is approximated at 0.5 per million children/year, thus representing approximately one quarter of children admitted with ADEM (denominator: 2009 Canadian surveillance data).

The dispersion of spherical droplets in source-sink flows and their relevance to the COVID-19 pandemic.

In this paper, we investigate the dynamics of spherical droplets in the presence of a source-sink pair flow field. The dynamics of the droplets is governed by the Maxey-Riley equation with the Basset-Boussinesq history term neglected. We find that, in the absence of gravity, there are two distinct behaviors for the droplets: small droplets cannot go further than a specific distance, which we determine analytically, from the source before getting pulled into the sink. Larger droplets can travel further from the source before getting pulled into the sink by virtue of their larger inertia, and their maximum traveled distance is determined analytically. We investigate the effects of gravity, and we find that there are three distinct droplet behaviors categorized by their relative sizes: small, intermediate-sized, and large. Counterintuitively, we find that the droplets with a minimum horizontal range are neither small nor large, but of intermediate size. Furthermore, we show that in conditions of regular human respiration, these intermediate-sized droplets range in size from a few µm to a few hundred µm. The result that such droplets have a very short range could have important implications for the interpretation of existing data on droplet dispersion.

Dinitrogen Cleavage by a Three-Coordinate Molybdenum(III) Complex.

Cleavage of the relatively inert dinitrogen (N(2)) molecule, with its extremely strong N identical withN triple bond, has represented a major challenge to the development of N(2) chemistry. This report describes the reductive cleavage of N(2) to two nitrido (N(3-)) ligands in its reaction with Mo(NRAr)(3), where R is C(CD(3))(2)CH(3) and Ar is 3,5-C(6)H(3)(CH(3))(2'), a synthetic three-coordinate molybdenum(III) complex of known structure. The formation of an intermediate complex was observed spectroscopically, and its conversion (with N identical withN bond cleavage) to the nitrido molybdenum(VI) product N identical withMo(NRAr)(3) followed first-order kinetics at 30 degrees C. It is proposed that the cleavage reaction proceeds by way of an intermediate complex in which N(2) bridges two molybdenum centers.

Female rugby union injuries in New Zealand: A review of five years (2013-2017) of Accident Compensation Corporation moderate to severe claims and costs.

OBJECTIVES: To provide epidemiological data and related costs for moderate-to-serious and serious injury claims for women's rugby union in New Zealand. DESIGN: A retrospective analytical review of injury entitlement claims for women's rugby from 2013 to 2017. METHODS: Data were analysed by year of competition, age, body site and injury type for total and moderate-to-severe (MSC) Accident Compensation Corporation (ACC) claims and costs. RESULTS: Over 2013 to 2017 there were 26,070 total claims for female rugby union costing $18,440,812 [AD$16,956,998]. The 15-19-year age group recorded 40% (n=1,009) of the total female rugby union Moderate-to-serious and serious (MSC) claims and 41% ($5,419,157 [AD$4,983,112]) of the total female rugby union MSC costs. The knee was the most commonly recorded injury site accounting for 40.3% (n=1,007) of MSC claims and 46.9% ($6,229,714 [AD$5,728732]) of MSC costs with an average cost of $1,245,943 ±$217,796 [AD$595,351 ±AD$104,070] per-year for female rugby union. CONCLUSIONS: This is the first study to report the nature and related costs for moderate-to-serious and serious injury claims for women's rugby union in New Zealand. A total of 26,070 injury claims were lodged over the duration of the study but only 9.6% (n=2,501) of these were classified as MSC injury entitlement claims. Participants 25 years and older accounted for 31% of the female rugby union player claims. Females in the over 35-year age groups compete against younger participants which may account for the higher mean cost per-claim seen as the age groups increase in years until they retire from the game.

Ascending placentitis in the mare: A review.

Ascending placentitis is a condition that occurs late in pregnancy when bacteria enter the sterile uterus from the lower reproductive tract. It leads to abortion or the birth of premature and weakened foals. Early detection and treatment of this condition is vital for ensuring the production of a viable foal.Mares with ascending placentitis often present in late term pregnancy with signs of premature udder development and premature lactation. There may be a vulvar discharge. Early detection of placental problems is possible using trans-abdominal or trans-rectal ultrasonography. Hormones such as progesterone and relaxin may be measured as indicators of foetal stress and placental failure. Postpartum foetal membranes may be thickened and contain a fibronecrotic exudate. The region most affected is the cervical star. Definitive diagnosis of ascending placentitis is by histopathological examination of the chorioallantoic membrane.Ideal treatment strategies are aimed at curing the infection and prolonging the pregnancy to as close to term as possible and consist of anti-microbials, anti-inflammatories and hormonal support.Swabs are taken from affected mares to determine antibiotic sensitivity and to aid in treatment of foals born from these mares which are at risk of becoming septic. If detected early enough, the chances of producing a viable foal are greatly increased.

Regulatory myosin light-chain genes of Caenorhabditis elegans.

We have cloned and analyzed the Caenorhabditis elegans regulatory myosin light-chain genes. C. elegans contains two such genes, which we have designated mlc-1 and mlc-2. The two genes are separated by 2.6 kilobases and are divergently transcribed. We determined the complete nucleotide sequences of both mlc-1 and mlc-2. A single, conservative amino acid substitution distinguishes the sequences of the two proteins. The C. elegans proteins are strongly homologous to regulatory myosin light chains of Drosophila melanogaster and vertebrates and weakly homologous to a superfamily of eucaryotic calcium-binding proteins. Both mlc-1 and mlc-2 encode abundant mRNAs. We mapped the 5' termini of these transcripts by using primer extension sequencing of mRNA templates. mlc-1 mRNAs initiate within conserved hexanucleotides at two different positions, located at -28 and -38 relative to the start of translation. The 5' terminus of mlc-2 mRNA is not encoded in the 4.8-kilobase genomic region upstream of mlc-2. Rather, mlc-2 mRNA contains at its 5' end a short, untranslated leader sequence that is identical to the trans-spliced leader sequence of three C. elegans actin genes.

Frameshift suppressor mutations outside the anticodon in yeast proline tRNAs containing an intervening sequence.

Extragenic suppressors of +1 frameshift mutations in proline codons map in genes encoding two major proline tRNA isoacceptors. We have shown previously that one isoacceptor encoded by the SUF2 gene (chromosome 3) contains no intervening sequence. SUF2 suppressor mutations result from the base insertion of a G within a 3'-GGA-5' anticodon, allowing the tRNA to read a 4-base code word. In this communication we describe suppressor mutations in genes encoding a second proline tRNA isoacceptor (wild-type anticodon 3'-GGU-5') that result in a novel mechanism for translation of a 4-base genetic code word. The genes that encode this isoacceptor include SUF7 (chromosome 13), SUF8 (chromosome 8), trn1 (chromosome 1), and at least two additional unmapped genes, all of which contain an intervening sequence. We show that suppressor mutations in the SUF7 and SUF8 genes result in G-to-U base substitutions at position 39 that disrupted the normal G . C base pairing in the last base pair of the anticodon stem adjacent to the anticodon loop. These anticodon stem mutations might alter the size of the anticodon loop and permit the use of a 3'-GGGU-5' sequence within the loop to read 4-base proline codons. Uncertainty regarding the exact structure of the mature suppressor tRNAs results from the possibility that anticodon stem mutations might affect sites of intervening sequence removal. The possible role of the intervening sequence in the generation of mature suppressor tRNA is discussed. Besides an analysis of suppressor tRNA genes, we have extended previous observations of the apparent relationship between tRNA genes and repetitive delta sequences found as solo elements or in association with the transposable element TY1. Hybridization studies and a computer analysis of the DNA sequence surrounding the SUF7 gene revealed two incomplete, inverted delta sequences that form a stem and loop structure located 165 base pairs from the 5' end of the tRNA gene. In addition, sequences beginning 164 base pairs from the 5' end of the trn1 gene also exhibit partial homology to delta. These observations provide further evidence for a nonrandom association between tRNA genes and delta sequences.

A strain-mediated corrosion model for bioabsorbable metallic stents.

This paper presents a strain-mediated phenomenological corrosion model, based on the discrete finite element modelling method which was developed for use with the ANSYS Implicit finite element code. The corrosion model was calibrated from experimental data and used to simulate the corrosion performance of a WE43 magnesium alloy stent. The model was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile. The non-linear plastic strain model, extrapolated from the experimental data, was also found to adequately capture the corrosion-induced reduction in the radial stiffness of the stent over time. The model developed will help direct future design efforts towards the minimisation of plastic strain during device manufacture, deployment and in-service, in order to reduce corrosion rates and prolong the mechanical integrity of magnesium devices. STATEMENT OF SIGNIFICANCE: The need for corrosion models that explore the interaction of strain with corrosion damage has been recognised as one of the current challenges in degradable material modelling (Gastaldi et al., 2011). A finite element based plastic strain-mediated phenomenological corrosion model was developed in this work and was calibrated based on the results of the corrosion experiments. It was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile and the corrosion-induced reduction in the radial stiffness of the stent over time. To the author's knowledge, the results presented here represent the first experimental calibration of a plastic strain-mediated corrosion model of a corroding magnesium stent.

Application of europium(III) chelate-dyed nanoparticle labels in a competitive atrazine fluoroimmunoassay on an ITO waveguide.

We have demonstrated the use of an optical indium tin oxide (ITO) (quartz) waveguide as a new platform for immunosensors with fluorescent europium(III) chelate nanoparticle labels (Seradyn) in a competitive atrazine immunoassay. ITO as a solid surface facilitated the successful use of particulate labels in a competitive assay format. The limit of detection in the new nanoparticle assay was similar to a conventional ELISA. The effect of particle size on bioconjugate binding kinetics was studied using three sizes of bioconjugated particle labels (107, 304, and 396nm) and a rabbit IgG/anti-IgG system in a 96-well plate. A decrease in particle size resulted in faster binding but did not increase the assay sensitivity. Flux calculations based on the particle diffusivity prove that faster binding of the small particles in this study was primarily due to diffusion kinetics and not necessarily to a higher density of antibodies on the particle surface. The results suggest that ITO could make a good platform for an optical immunosensor using fluorescent nanoparticle labels in a competitive assay format for small molecule detection. However, when used in combination with fluorescent particulate labels, a highly sensitive excitation/detection system needs to be developed to fully utilize the kinetic advantage from small particle size. Different regeneration methods tested in this study showed that repeated washings with 0.1 M glycine-HCl facilitated the reuse of the ITO waveguide.

The clinical effectiveness and cost-effectiveness of newer drugs for children with epilepsy. A systematic review.

OBJECTIVES: To examine the clinical effectiveness and cost-effectiveness of newer antiepileptic drugs (AEDs) for epilepsy in children: gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate and vigabatrin. DATA SOURCES: Electronic databases. Drug company submissions. REVIEW METHODS: For the systematic review of clinical and cost-effectiveness, studies were assessed for inclusion according to predefined criteria. Data extraction and quality assessment were also undertaken. A decision-analytic model was constructed to estimate the cost-effectiveness of the newer agents in children with partial seizures, the only condition where there were sufficient trial data to inform a model. RESULTS: The quality of the randomised controlled trial (RCT) data was generally poor. For each of the epilepsy subtypes considered in RCTs identified for this review (partial epilepsy with or without secondary generalisation, Lennox-Gastaut syndrome, infantile spasms, absence epilepsy and benign epilepsy with centrotemporal spikes), there is some evidence from placebo-controlled trials that the newer agents tested are of some value in the treatment of these conditions. Where active controls have been used, the limited evidence available does not indicate a difference in effectiveness between newer and older drugs. The data are not sufficient to inform a prescribing strategy for any of the newer agents in any of these conditions. In particular, there is no clinical evidence to suggest that the newer agents should be considered as a first-choice treatment in any form of epilepsy in children. Annual drug costs of the newer agents ranges from around 400 pound to 1200 pound, depending on age and concomitant medications. An AED that is ineffective or has intolerable side-effects will only be used for a short period of time, and many patients achieving seizure freedom will successfully withdraw from drug treatment without relapsing. The results of the decision-analytic model do not suggest that the use of the newer agents in any of the scenarios considered is clearly cost-effective but, similarly, do not indicate that they are clearly not cost-effective. CONCLUSIONS: The prognosis for children diagnosed with epilepsy is generally good, with a large proportion responding well to the first treatment given. A substantial proportion, however, will not respond well to treatment, and for these patients the clinical goal is to find an optimal balance between the benefits and side-effects of any treatment given. For the newly, or recently, diagnosed population, the key question for the newer drugs is how soon they should be tried. The cost-effectiveness of using these agents early, in place of one of the older agents, will depend on the effectiveness and tolerability of these agents compared with the older agents; the evidence from the available trial data so far suggests that the newer agents are no more effective but may be somewhat better tolerated than the older agents, and so the cost-effectiveness for early use will depend on the trade-off between effectiveness and tolerability, both in terms of overall (long-term) treatment retention and overall utility associated with effects on seizure rate and side-effects. There are insufficient data available to estimate accurately the nature of this trade off either in terms of long-term treatment retention or utility. Better information is required from RCTs before any rational evidence-based prescribing strategy could be developed. Ideally, RCTs should be conducted from a 'public health' perspective, making relevant comparisons and incorporating outcomes of interest to clinicians and patients, with sufficiently long-term follow-up to determine reliably the clinical utility of different treatments, particularly with respect to treatment retention and the balance between effectiveness and tolerability. RCTs should mirror clinical practice with respect to diagnosis, focusing on defined syndromes or, where no syndrome is identified, on groups defined by specific seizure type(s) and aetiology. Epilepsy in children is a complex disease, with a variety of distinct syndromes and many alternative treatment options and outcomes. Diagnosis-specific decision-analytic models are required; further research may be required to inform parameter values adequately with respect to epidemiology and clinical practice.

Reticulostimulating properties of killed vaccines of anaerobic coryneforms and other organisms.

Vaccines prepared from 115 strains of anaerobic coryneforms and other organisms were tested in mice for their reticulostimulating ability as judged by the degree of spleen hypertrophy produced after ip injection. Almost all vaccines caused a statistically significant increase in spleen weight, but the ability to produce spleen ratios (test mean wt:control mean wt) of 4 or more was confined to Propionibacterium acnes and P. avidum strains. P. acnes, type II, gave high spleen ratios more frequently than strains of any other type.

Questionnaire identifying management practices surrounding calving on spring-calving dairy farms and their associations with herd size and herd expansion.

Healthy calves are fundamental to any profitable dairy enterprise. Research to-date, has focused on year-round calving systems which experience many different challenges compared to spring-calving systems. The objective of the present study was to determine the on-farm dry cow, calving, and colostrum management practices of spring-calving dairy production systems, and quantify their associations with herd size and herd expansion status (i.e. expanding or not expanding). Information on these management practices was available from a survey of 262 Irish spring-calving dairy farmers, representative of the Irish national population. Herd expansion in the 2 years before, and the year that the survey was conducted was not associated with any of the management practices investigated. Fifty-three percent of respondents had an average calving season length of 10 to14 weeks with 35% of herds having a longer calving season. Previous research in cattle has documented that both colostrum source and feeding management are associated with the transmission of infectious disease from cow to calf. In the present study 60% of respondents fed calves colostrum from their own dam; however, 66% of those respondents allowed the calf to suckle the dam, 23% of survey respondents fed calves pooled colostrum. Larger herds were more likely (P<0.01) to use pooled colostrum supplies, while smaller herds were more likely (P<0.05) to allow the calf to suckle the dam. The majority (86%) of respondents had stored supplies of colostrum; average-sized herds had the greatest likelihood of storing colostrum (P<0.05), compared to other herd sizes; larger sized herds had a lesser likelihood (P<0.05) of storing colostrum in a freezer, compared to other herd sizes. Although freezing colostrum was the most common method used to store colostrum (54% of respondents), 17% of respondents stored colostrum at room temperature, 29% of which stored it at room temperature for greater than 4 days. The results from the present study indicate that a particular focus needs to be placed on calving and colostrum management because this study has highlighted a number of areas which are below international standards, and may have repercussions for calf health. Furthermore, management practices on larger farms could be improved and, as these represent the future of dairy farming, a focus needs to be placed on them. Expanding herds are not a particular concern as herd expansion, independent of herd size, does not seem to be associated with calving and colostrum management practices on Irish spring-calving dairy herds.

RASSF1A promoter region CpG island hypermethylation in phaeochromocytomas and neuroblastoma tumours.

Deletions of chromosome 3p are frequent in many types of neoplasia including neural crest tumours such as neuroblastoma (NB) and phaeochromocytoma. Recently we isolated several candidate tumour suppressor genes (TSGs) from a 120 kb critical interval at 3p21.3 defined by overlapping homozygous deletions in lung and breast tumour lines. Although mutation analysis of candidate TSGs in lung and breast cancers revealed only rare mutations, expression of one of the genes (RASSF1A) was absent in the majority of lung tumour cell lines analysed. Subsequently methylation of a CpG island in the promoter region of RASSF1A was demonstrated in a majority of small cell lung carcinomas and to a lesser extent in non-small cell lung carcinomas. To investigate the role of 3p TSGs in neural crest tumours, we (a) analysed phaeochromocytomas for 3p allele loss (n=41) and RASSF1A methylation (n=23) and (b) investigated 67 neuroblastomas for RASSF1A inactivation. 46% of phaeochromocytomas showed 3p allele loss (38.5% at 3p21.3). RASSF1A promoter region hypermethylation was found in 22% (5/23) of sporadic phaeochromocytomas and in 55% (37/67) of neuroblastomas analysed but RASSF1A mutations were not identified. In two neuroblastoma cell lines, methylation of RASSF1A correlated with loss of RASSF1A expression and RASSF1A expression was restored after treatment with the demethylating agent 5-azacytidine. As frequent methylation of the CASP8 gene has also been reported in neuroblastoma, we investigated whether RASSF1A and CASP8 methylation were independent or related events. CASP8 methylation was detected in 56% of neuroblastomas with RASSF1A methylation and 17% without RASSF1A methylation (P=0.0031). These results indicate that (a) RASSF1A inactivation by hypermethylation is a frequent event in neural crest tumorigenesis, particularly neuroblastoma, and that RASSF1A is a candidate 3p21.3 neuroblastoma TSG and (b) a subset of neuroblastomas may be characterized by a CpG island methylator phenotype.

Splicing of a yeast proline tRNA containing a novel suppressor mutation in the anticodon stem.

The intron-containing proline tRNAUGG genes in Saccharomyces cerevisiae can mutate to suppress +1 frameshift mutations in proline codons via a G to U base substitution mutation at position 39. The mutation alters the 3' splice junction and disrupts the bottom base-pair of the anticodon stem which presumably allows the tRNA to read a four-base codon. In order to understand the mechanism of suppression and to study the splicing of suppressor pre-tRNA, we determined the sequences of the mature wild-type and mutant suppressor gene products in vivo and analyzed splicing of the corresponding pre-tRNAs in vitro. We show that a novel tRNA isolated from suppressor strains is the product of frameshift suppressor genes. Sequence analysis indicated that suppressor pre-tRNA is spliced at the same sites as wild-type pre-tRNA. The tRNA therefore contains a four-base anticodon stem and nine-base anticodon loop. Analysis of suppressor pre-tRNA in vitro revealed that endonuclease cleavage at the 3' splice junction occurred with reduced efficiency compared to wild-type. In addition, reduced accumulation of mature suppressor tRNA was observed in a combined cleavage and ligation reaction. These results suggest that cleavage at the 3' splice junction is inefficient but not abolished. The novel tRNA from suppressor strains was shown to be the functional agent of suppression by deleting the intron from a suppressor gene. The tRNA produced in vivo from this gene is identical to that of the product of an intron+ gene, indicating that the intron is not required for proper base modification. The product of the intron- gene is a more efficient suppressor than the product of an intron+ gene. One interpretation of this result is that inefficient splicing in vivo may be limiting the steady-state level of mature suppressor tRNA.

Frameshift suppression in Saccharomyces cerevisiae. V. Isolation and genetic properties of nongroup-specific suppressors.

Two classes of frameshift suppressors distributed at 22 different loci were identified in previous studies in the yeast Saccharomyces cerevisiae. These suppressors exhibited allele-specific suppression of +1 G:C insertion mutations in either glycine or proline codons, designated as group II and group III frameshift mutations, respectively. Genes corresponding to representative suppressors of each group have been shown to encode altered glycine or proline tRNAs containing four base anticodons.--This communication reports the existence of a third class of frameshift suppressor that exhibits a wider range in specificity of suppression. The suppressors map at three loci, suf12, suf13, and suf14, which are located on chromosomes IV, XV, and XIV, respectively. The phenotypes of these suppressors suggest that suppression may be mediated by genes other than those encoding the primary structure of glycine or proline tRNAs.

Frameshift suppression in Saccharomyces cerevisiae. III. Isolation and genetic properties of group III suppressors.

Suppressors of ICR-induced mutations that exhibit behavior similar to bacterial frameshift suppressors have been identified in the yeast Saccharomyces cerevisiae. The yeast suppressors have been divided into two groups. Previous evidence indicated that suppressors of one group (Group II: SUF1, SUF3, SUF4, SUF5 and SUF6) represent mutations in the structural genes for glycyl-tRNA's. Suppressors of the other group (Group III: SUF2 and SUF7) were less well characterized. Although they suppressed some ICR-revertible mutations, they failed to suppress Group II frameshift mutations. This communication provides a more thorough characterization of the Group III suppressors and describes the isolation and properties of four new suppressors in that group (SUF8, SUF9, SUF10 and suf11).--In our original study, Group III suppressors were isolated as revertants of the Group III mutations his4-712 and his4-713. All suppressors obtained as ICR-induced revertants of these mutations mapped at the SUF2 locus near the centromere of chromosome III. Suppressors mapping at other loci were obtained in this study by analyzing spontaneous and UV-induced revertants of the Group III mutations. SUF2 and SUF10 suppress both Group III his4 mutations, whereas SUF7, SUF8, SUF9 and suf11 suppress his4-713, but not his4-712. All of the suppressors except suf11 are dominant in diploids homozygous for his4-713. The suppressors fail to suppress representative UAA, UAG and UGA nonsense mutations.--SUF9 is linked to the centromere of chromosome VI, and SUF10 is linked to the centromere of chromosome XIV. A triploid mapping procedure was used to determine the chromosome locations of SUF7 and SUF8. Subsequent standard crosses revealed linkage of SUF7 to cdc5 on chromosome Xiii and linkage of SUF8 to cdc12 and pet3 on chromosome VIII.