Developmental and behavioural phenotype in Noonan syndrome?

Developmental and behavioural phenotype in Noonan syndrome? Noonan syndrome is characteristic by facial dysmorphology, congenital heart defects, short stature, developmental retardation and severe early feeding disorders in many cases. Data from a postal survey on physical development, feeding difficulties, developmental problems and behavioural aspects in 26 children are reported. The findings suggest developmental and behavioural difficulties in 46 per cent, but do not support the notion of a behavioural phenotype specific to Noonan syndrome. Having to cope with early surgery, feeding, developmental and behavioural problems establishes a need for psychological counseling for families receiving a diagnosis of Noonan syndrome.     

Are flower-visiting ants mutualists or antagonists? A study in a gynodioecious wild strawberry

Ants are common flower visitors, but their effects on plant reproductive fitness have not often been assessed. Flower-visiting ants were studied to determine whether they are antagonists or mutualists and whether they could influence floral or breeding system evolution in gynodioecious wild strawberry (Fragaria virginiana). Ant and flying pollinator (bees/flies) access to plants was manipulated, and visitation, fruit, and seed set were assessed. Ants visited flowers of hermaphrodites more often than those of females when bees and flies were excluded, but visited the sex morphs equally when they were present. Insect class did not influence fruit or seed set of hermaphrodites. In contrast, ants had both positive and negative effects on seed set in females. Females visited only by ants had 90% of the seed set of those visited only by bees/flies, and their seed set increased with ant visitation. The spatial pattern of seed set, however, suggests that ants may also damage pistils. Lastly, in contrast to bees and flies, ants failed to increase visitation with floral display size, suggesting that ant presence at flowers could reduce selection on this attractive trait. Findings suggest that when in high abundance, flower-visiting ants could affect breeding system and floral evolution in this gynodioecious plant.     

Queen pheromones in Temnothorax ants: control or honest signal?

Background  

The division of reproductive labor among group members in insect societies is regulated by "queen pheromones". However, it remains controversial whether these are manipulative, i.e., actively suppress worker reproduction, or honestly signal the fertility status of the queen to which workers react in their own interest by refraining from laying eggs. Manipulative queen control is thought to lead to an evolutionary arms race between queens and workers, resulting in complex queen bouquets that diverge strongly among different populations and species. In contrast, honest signals would evolve more slowly and might therefore differ less strongly within and among species.     

To be folded or to be unfolded?

The lack of ordered structure in “natively unfolded” proteins raises a general question: Are there intrinsic properties of amino acid residues that are responsible for the absence of fixed structure at physiological conditions? In this article, we demonstrate that the competence of a protein to be folded or to be unfolded may be determined by the property of amino acid residues to form a sufficient number of contacts in a globular state. The expected average number of contacts per residue calculated from the amino acid sequence alone (using the average number of contacts for 20 amino acid residues in globular proteins) can be used as one of the simple indicators of natively unfolded proteins. The prediction accuracy for the sets of 80 folded and 90 natively unfolded proteins reaches 89% if the expected average number of contacts is used as a parameter and 83% in the case of hydrophobicity. An optimal set of artificial parameters for 20 amino acid residues obtained by Monte Carlo algorithm to maximally separate the sets of 90 natively unfolded and 80 folded proteins demonstrates the upper limit for prediction accuracy, which is 95%.     

To be or not to be ubiquitinated?

Levels of p21, a cyclin-dependent kinase (CDK) inhibitor, are controlled in part at the post-translational level by protein degradation. Although the signaling pathways leading to p21 degradation have not yet been fully elucidated, it is evident that p21 ubiquitination is an essential factor in its degradation. We discuss that, with the only notable exception of ornithine decarboxylase, ubiquitination appears to be a prerequisite for proteasomal degradation rather than an unnecessary byproduct of such proteolysis.     

Neotyphodium endophytes in grasses: deterrents or promoters of herbivory by leaf-cutting ants?

Endophytic fungi, particularly in the genus Neotyphodium, are thought to interact mutualistically with host grasses primarily by deterring herbivores and pathogens via production of alkaloidal mycotoxins. Little is known, however, about how these endophytes interact with host plants and herbivores outside the realm of agronomic forage grasses, such as tall fescue, and their livestock grazers or invertebrate pest herbivores. We tested the effects of Neotyphodium inhabiting introduced tall fescue and native Arizona fescue on preference, survival, and performance of the leaf-cutting ant, Acromyrmex versicolor, an important generalist herbivore in the southwestern United States. In a choice experiment, we determined preferences of foraging queens and workers for infected and uninfected tall fescue and Arizona fescue. In a no-choice experiment, we determined queen survival, worker production, and size of fungal gardens for foundress queens reared on diets of infected and uninfected tall fescue and Arizona fescue. Foraging workers and queens did not significantly prefer either uninfected tall fescue or Arizona fescue relative to infected grasses, although ants tended to harvest more uninfected than infected tall fescue and more infected than uninfected Arizona fescue. Queen survivorship and length of survival was greater on uninfected tall fescue, uninfected Arizona fescue, and infected Arizona fescue than on infected tall fescue or the standard diet of palo verde and mesquite leaves. No queens survived beyond 6 weeks of the study when fed the infected tall fescue diet, in contrast to the effects of the other diets. Likewise, worker production was much lower and fungal garden size much smaller on infected tall fescue than in all other treatments, including the standard diet. In general, ant colonies survived and performed better on uninfected tall fescue and infected and uninfected Arizona fescue than standard diets of palo verde and mesquite leaves. The interaction of Neotyphodium with its host grasses is highly variable and these endophytes may increase, not alter, or even decrease resistance to herbivores. The direction of the interaction depends on host and fungal genotype, herbivore species, and environmental factors. The presence of endophytes in most, if not all, host plants suggests that endophytes may alter foraging patterns, performance, and survival of herbivores, such as leaf-cutting ants, but not always in ways that increase host plant fitness. Received: 27 October 1998 / Accepted: 19 October 1998     

McKusick-Kaufman or Bardet-Biedl syndrome? A new borderline case in an Italian nonconsanguineous healthy family

McKusick-Kaufman syndrome (MKS, OMIM #236700) is a rare syndrome inherited in an autosomal recessive pattern with a phenotypic triad comprising hydrometrocolpos (HMC), postaxial polydactyly (PAP), and congenital cardiac disease (CHD). The syndrome is caused by mutations in the MKKS gene mapped onto chromosome 20p12 between D20S162 and D20S894 markers. Mutations in the same gene causes Bardet-Biedl-6 syndrome (BBS-6, OMIM #209900) inherited in an autosomal recessive pattern. BBS-6 comprises retinitis pigmentosa, polydactyly, obesity, mental retardation, renal and genital anomalies. HMC, CHD, and PAP defects can also occur in BBS-6, and there is a significant clinical overlap between MKS and BBS-6 in childhood. We describe a new borderline case of MKS and BBS syndrome and suggest insights for understanding correlation between MKKS gene mutations and clinical phenotype. Here, we report the results of molecular analysis of MKKS in a female proband born in an Italian nonconsanguineous healthy family that presents HMC and PAP. The mutational screening revealed the presence of two different heterozygous missense variants (p.242A>S in exon 3, p.339 I>V in exon 4) in the MKKS gene, and a nucleotide variation in 5'UTR region in exon 2 (-417 A>C).     

A role for phytotoxins in thePhragmites die-back syndrome?

Die-back and healthy stands ofPhragmites australis (Cav.) Trin. exSteud., in the U.K. and Hungary, were compared in terms of plant morphology and anatomy, sediment redox potential and sulphide levels and plant resistance to internal Poiseuille gas flow. In laboratory experiments rhizome cuttings were exposed to acetic acid or dissolved sulphide in unstirred solution cultures in order to determine whether the die-back symptoms found in the field could be induced by these phytotoxins. Most of the die-back symptoms, namely stunting of adventitious roots and laterals, bud death, callus blockages of the gas-pathways, and vascular blockages (both xylem and phloem), were produced by each of the phytotoxin treatments. These symptoms were largely absent from healthy field sites and from the experimental controls. In a greenhouse experiment, plants were grown in waterlogged sand or loam, with or without a sub-surface organic layer composed of chopped up rhizomes and roots mixed with the soil base. Especially during the first 70 days, redox levels were considerably lowered, and shoot numbers and shoot growth much reduced by the presence of the organic layers; the effects were most pronounced in the sand plus organic matter treatment. It is suggested that accumulated phytotoxins, e.g. orgnaic acids and/or sulphide, whether produced from the death and decay of the plant, or from excessive organic loading or as an indirect results of eutrophication, will perpetuate the die-back ofPhragmites and prevent the recovery of the plant in the short term.     

Nestmate recognition in Camponotus floridanus callow worker ants: are sisters or nestmates recognized?

Callow workers of the Florida carpenter ant, Camponotus floridanus Buckley, reared with their sisters displayed more aggressive acts towards unrelated unfamiliar foragers than towards related unfamiliar foragers. When callows were reared with foreign nurses they were more aggressive towards their own unfamiliar sisters than towards the unfamiliar sisters of their nurses. Thus callow workers recognized the sisters of the workers they were reared with as nestmates. This ability was not dependent on whether or not callows received cues from older ants during their emergence. Similarly, a forager was less aggressive towards unfamiliar callows reared with its sisters than towards those reared with nurses unrelated to itself. In addition, foragers were less aggressive towards their callow sisters than towards unrelated callows, regardless of the relatedness between the foragers and the rearing nurses.     

Free radicals in chronic fatigue syndrome: cause or effect?

We have demonstrated that certain morphological and biochemical changes occur in chronic fatigue syndrome (CFS) and in rheumatoid arthritis (RA). These changes in RA can be explained by the well-established inappropriate increase in free radical generation. The similar changes in CFS suggest a similar explanation and a possible role for free radicals in the aetiology of this condition.     

Do I stand out or blend in? Conspicuousness awareness and consistent behavioural differences in hermit crabs

Animals titrate their behaviour against the level of risk and an individual's conspicuousness should influence decisions such as when to flee and for how long to hide. Conspicuousness will vary with variation in substrate colour. Since hermit crabs frequently change the shells they occupy, shell colour will also influence conspicuousness and to be aware of their conspicuousness would require information on both of these factors to be integrated. Reduced boldness in high-contrast shell and substrate combinations compared with situations of low contrast indicates that hermit crabs are aware of current conspicuousness. Differences between individuals remained consistent across conspicuousness levels indicating the presence of animal personalities.     

Can Aging in Place Be Cost Effective? A Systematic Review

Purpose of the Study

To systematically review cost, cost-minimization and cost-effectiveness studies for assisted living technologies (ALTs) that specifically enable older people to ‘age in place’ and highlight what further research is needed to inform decisions regarding aging in place.

Design

People aged 65+ and their live-in carers (where applicable), using an ALT to age in place at home opposed to a community-dwelling arrangement.

Methods

Studies were identified using a predefined search strategy on two key economic and cost evaluation databases NHS EED, HEED. Studies were assessed using methods recommended by the Campbell and Cochrane Economic Methods Group and presented in a narrative synthesis style.

Results

Eight eligible studies were identified from North America spread over a diverse geographical range. The majority of studies reported the ALT intervention group as having lower resource use costs than the control group; though the low methodological quality and heterogeneity of the individual costs and outcomes reported across studies must be considered.

Implications

The studies suggest that in some cases ALTs may reduce costs, though little data were identified and what there were was of poor quality. Methods to capture quality of life gains were not used, therefore potential effects on health and wellbeing may be missed. Further research is required using newer developments such as the capabilities approach. High quality studies assessing the cost-effectiveness of ALTs for ageing in place are required before robust conclusion on their use can be drawn.     

Prader-Willi syndrome: Methylation study or fluorescence in situ hybridization first?

Prader-Willi syndrome (PWS) is neurogenetic disorder involving the imprinting mechanism at 15q11-13 region. We report a 4-year-old girl who was referred to our laboratory to be investigated for clinical obesity, mental deficiency and respiratory problems. The patient was born for non-consanguineous and healthy biological parents. After normal pregnancy, the patient was delivered by cesarean section at full term, with a birth weight of 2500 g, and the height and head circumference were unknown. In neonatal stage, she presented severe hypotonia with feeding problems. Her developmental progress was delayed. She walked and developed speech at the age of 3 years. Since the age of 3 years, she presented severe dental problems. Methylation study had confirmed the diagnosis, and for detecting etiology, fluorescence in situ hybridization using probes for small nuclear ribonucleoprotein polypeptide N (SNRPN), which map inside the chromosomal region 15q11-15q13, was necessary to confirm the 15q11-15q13 deletion of paternal chromosome 15, which is the predominant genetic defect in PWS. In conclusion, we report this case with an objective to reinforce the necessity of analysis of DNA methylation within the 15q11-13 region, which is an important tool for the correct diagnosis among children presenting with neonatal hypotonia, mental deficiency and obesity.     

Congruency of hydrocarbon patterns in heterospecific groups of ants: transfer and/or biosynthesis?

Summary In homospecific groups of ants, each species has its own hydrocarbon profile, on the epicuticle and in the postpharyngeal gland (PPG). When reared together in bispecific groups, workers of both species possess each other's hydrocarbons in both locations. The present study investigated two alternative mechanisms by which a mixed odour in artificial groups ofFormica selysi/Manica rubida can be created. Using [1-¹⁴C] sodium acetate as a precursor,de novo biosynthesis of hydrocarbons was demonstrated for both species whether reared in homospecific or mixed-species groups. The newly synthesized hydrocarbons occurred on the epicuticle, internally, and in particularly large amounts in the PPG. As expected from their PPG and epicuticular hydrocarbons composition, workersF. selysi synthesized alkanes and alkenes in comparable amounts irrespective of their rearing scheme. Likewise,M. rubida reared in bispecific groups synthesized mostly alkanes with only negligible amounts of alkenes, according to a ratio characteristic toM. rubida workers from homospecific groups and not toF. selysi workers. During dyadic encounters, a transfer of labeled hydrocarbons between nestmates (conspecific in homospecific groups and allospecific in mixed groups) was observed. These results suggest that the formation of the mixed hydrocarbon profile in artificial groups of ants is the result of a transfer of these chemicals between nestmates rather thande novo biosynthesis of the allospecific hydrocarbons. Behaviours like trophallaxis, grooming and body contact that occurred during the encounters mediated such a transfer.     

Cardiovascular disease with diabetes or the metabolic syndrome: should statins or fibrates be first line lipid therapy?

PURPOSE OF REVIEW: Subgroups with diabetes or with features of the metabolic syndrome have been increasingly highlighted in large clinical endpoint trials with lipid therapy. This review will focus on the results of trials with statins or fibrates and examine the strength of the evidence for major cardiovascular event reduction with each kind of therapy in these high-risk subgroups that typically have low-to-moderate levels of LDL cholesterol. RECENT FINDINGS: Of six statin trials in populations with moderately increased LDL cholesterol only one, the Heart Protection Study, has shown that statin therapy will significantly reduce the major coronary heart disease events of non-fatal myocardial infarction or coronary heart disease death in diabetes. None of these trials has shown that statins have a particular predilection for reducing cardiovascular events in individuals with higher levels of body weight or other features of the metabolic syndrome. There are far fewer trial data with fibrates than with statins. However, the Veterans Affairs High Density Lipoprotein Intervention Trial has shown that a fibrate can significantly reduce major cardiovascular events, most particularly coronary heart disease death, in those with diabetes as well as those without diabetes who have insulin resistance. Indeed, all fibrate trials show that this therapy appears to selectively benefit the individual with obesity and features of the metabolic syndrome. SUMMARY: Based principally on evidence from the Veterans Affairs High Density Lipoprotein Intervention Trial and the cumulative experience with statins, trial data would thus far suggest that the patient with a modest increase in LDL cholesterol who has diabetes or features of the metabolic syndrome might be likely to achieve more substantial cardiovascular benefit from fibrate than from statin therapy.