Standardization of prey immunomarking: does a positive test always indicate predation?

A prey immunomarking procedure (PIP) in combination with generic anti-rabbit and anti-chicken immunoglobulin G (IgG) enzyme-linked immunosorbent assays (ELISAs) are used frequently to study arthropod predation. This study was conducted to: (1) further standardize the PIP as a tool for predator gut analysis research, (2) investigate the most effective means for administering IgG marks to prey items, and (3) assess the possibility of the PIP yielding false positive reactions as a consequence of a predator obtaining a mark by incidental contact with, or by a failed predation attempt on, a protein-marked prey item. The pest Lygus hesperus Knight (Hemiptera: Miridae) was tagged with either an external rabbit IgG mark, an internal chicken IgG mark, or a double (external rabbit IgG and internal chicken IgG) mark treatment. Then, the variously marked prey items were fed to chewing and piercing-sucking type predators and their gut contents were examined for the presence of IgG remains. Data revealed that all three marking treatments were highly effective at tagging targeted prey. However, ELISA results showed that the prey items should only be marked internally to maximize the likelihood of detecting prey remains while minimizing the risk of obtaining false positive errors. The merits and limitations of using the generic PIP for predator gut analysis research are discussed.     

Cancer cachexia’s metabolic signature in a murine model confirms a distinct entity

Despite recent consensus definitions, lack of specific biomarkers remains a hurdle towards a more accurate and efficient diagnosis of cancer cachexia, distinguishing cachexia as a separate entity from other wasting syndromes. In a previous pilot study, we have shown that cancer-cachectic mice have a unique metabolic fingerprint with distinct glucose and lipid alterations compared to healthy controls. Further metabolomics studies were carried out to investigate differences in metabolic profiles of cancer-cachectic mice to tumor-bearing non-cachectic mice, calorie-restricted mice, and surgically treated cancer-cachectic mice. CD2F1 mice were divided into: (1) Cachexia Group received cachexia-inducing C26 undifferentiated colon carcinoma cells; (2) Tumor-Burden Group received, non-cachectic, P388 lymphoma cells; (3) Caloric-Restriction Group, remaining cancer-free, but subjected to caloric-restriction; (4) Surgery Group, similar to Cachexia Group, but tumors resected mid-experiment; and (5) Control Group aged intact. Baseline, mid-experiment and final serum samples were collected for ¹H NMR spectroscopic analysis. After data reduction, unsupervised principal component analysis and orthogonal projections to latent structures analyses demonstrate that the unique metabolic fingerprint is independent of tumor-burden and distinct from profiles of caloric-restriction and aging. Hyperlipidemia, hyperglycemia, and reduced branched-chain amino acids distinguish cachexia from other groups. Furthermore, the profile of surgically treated mice differs from that of cachectic mice, reverting to a profile more congruent with healthy controls indicating cachexia is amenable to correction where surgical cure is possible. That metabolomic analysis of murine serum is able to differentiate cachexia from tumor-burden and caloric-restriction warrants similar translational investigations in patients to explore cancer cachexia’s unique biomarkers.     

Does glucagon have a positive inotropic effect in the human heart?

Glucagon is considered to exert cardiostimulant effects, most notably the enhancement of heart rate and contractility, due to the stimulation of glucagon receptors associated with Gs protein stimulation which causes adenylyl cyclase activation and the consequent increase in 3′,5′-cyclic adenosine monophosphate production in the myocardium. These effects have been extensively demonstrated in experimental studies in different animal species. However, efforts to extrapolate the experimental data to patients with low cardiac output states, such as acute heart failure or cardiogenic shock, have been disappointing. The experimental and clinical data on the cardiac effects of glucagon are described here.     

A distinct osteochondrodysplasia with hypertrichosis—Individualization of a probable autosomal recessive entity

Summary Two sibs and two other unrelated patients presented a distinct previously undescribed syndrome consisting of generalized congenital hypertrichosis, macrosomy at birth, narrow thorax, cardiomegaly, wide ribs, platyspondyly, hypoplastic ischiopubic branches, small obturator foramen, bilateral coxa valga, enlarged medullar canal, long bones shaped like an Erlenmeyer flasks and generalized osteopenia. The family data suggest autosomal recessive inheritance.     

Apathy syndrome: a clinical entity?

Apathy is defined as a disorder of motivation that expresses itself at an emotional, cognitive and behavioural level. Apathy can occur as a symptom and a syndrome. In the recent years diagnostic criteria and a number of scales for measuring apathy in elderly with psychiatric or neurological disorders have been introduced. Two scales are specifically developed to measure apathy, the Apathy Evaluation Scale (AES) from Marin and the Apathy Scale (AS) from Starkstein. Both scales have been translated into Dutch. The AS is more convenient. The AS in addition can be used when applying the criteria for the apathy syndrome which has been introduced in 2001 by Starkstein. In addition, the Neuropsychiatric Inventory (NPI) and the 'Gedragsobservatieschaal voor de Intramurale Psychogeniatrie' (GIP) (a scale in Dutch) have an apathy domain. Conceptual problems surrounding apathy have only partly been resolved. The criteria for the apathy syndrome can only be used for assessing the extent of the problem. Apathy and depression are strongly correlated. Studies show that apathy as a syndrome can occur without concomitant depression in the elderly, but regularly occurs besides a depressive disorder, in percentages varying between 9% and 53% of the population under study. Especially the varying validity of an apathy syndrome in relation to late life depression needs further clarification.     

Does dishonesty really invite third-party punishment? Results of a more stringent test

Many experiments have demonstrated that people are willing to incur cost to punish norm violators even when they are not directly harmed by the violation. Such altruistic third-party punishment is often considered an evolutionary underpinning of large-scale human cooperation. However, some scholars argue that previously demonstrated altruistic third-party punishment against fairness-norm violations may be an experimental artefact. For example, envy-driven retaliatory behaviour (i.e. spite) towards better-off unfair game players may be misidentified as altruistic punishment. Indeed, a recent experiment demonstrated that participants ceased to inflict third-party punishment against an unfair player once a series of key methodological problems were systematically controlled for. Noticing that a previous finding regarding apparently altruistic third-party punishment against honesty-norm violations may have been subject to methodological issues, we used a different and what we consider to be a more sound design to evaluate these findings. Third-party punishment against dishonest players withstood this more stringent test.     

Does coping style predict optimization? An experimental test in a wild passerine bird

A number of studies have suggested that avian brood size is individually optimized. Yet, optimal reproductive decisions likely vary owing to among-individual differences in environmental sensitivity. Specifically, ‘proactive’ individuals who do not track environmental changes may be less able to produce optimal brood sizes than ‘reactive’ individuals who have more precise local environmental knowledge. To test this, we quantified exploratory behaviour (a proxy for proactivity) in a great tit (Parus major) population, manipulated brood sizes (reduced, control, enlarged) and evaluated whether individuals of dissimilar coping style differed in their level of optimization. If reactive females behaved optimally, any deviation from their original brood size should lower fitness, whereas this should not be the case for proactive females. Reactive females indeed performed best at their natural brood size, whereas proactive females performed best when raising an enlarged brood. These findings imply that proactive females produced sub-optimal brood sizes. We speculate that proactive females might (i) take decisions based on biased perception of their environment, (ii) face energetic constraints in offspring production and/or (iii) be more willing to invest into current reproduction when given the option. Our findings provide experimental evidence for coping style-related differences in optimal reproductive decisions and life-history strategies.     

Does habitat fragmentation affect temperature-related life-history traits? A laboratory test with a woodland butterfly

Habitat fragmentation may change local climatic conditions leading to altered selection regimes for life-history traits in small ectotherms, including several insects. We investigated temperature-related performance in terms of fitness among populations of the woodland butterfly Pararge aegeria (L.) originating from populations of a closed, continuous woodland landscape versus populations of an open, highly fragmented agricultural landscape in central Belgium. Female fecundity and longevity were evaluated in a temperature-gradient experiment. As predicted, females of woodland landscape origin reached higher maximum daily fecundity and lifetime number of eggs than did agricultural landscape females at low ambient temperatures, but this reversed at high ambient temperature. Egg weight decreased with temperature, and eggs of woodland butterflies were smaller. Contrary to what is generally assumed, remaining thorax mass was a better predictor of lifetime reproductive output than was abdomen mass. Since we used the F2 generation from wild-caught females reared under common garden conditions, the observed effects are likely to rely on intrinsic, heritable variation. Our results suggest that differential selection regimes associated with different landscapes intervene by intraspecific variation in the response of a butterfly to variation in ambient temperature, and may thus be helpful when making predictions of future impacts on how wild populations respond to environmental conditions under a global change scenario, with increasing temperatures and fragmented landscapes.     

Partial monosomy of the long arm of chromosome 16: A distinct clinical entity?

Summary A 7-month-old male child with a de novo, seemingly belanced reciprocal 5p/16q translocation and karyotype 46,XY,t(5;16) (p14;q21), resulting from a maternal meiotic error, is described. The clinical findings in this patient are strikingly similar to those in the only patient with partial deletion 16q hitherto described, [del(16)(q21)], indicating that during the 5p/16q rearrangement, 16q material was lost and suggesting that partial or total deletion of the long arm of chromosome 16 distal to band q21 is accompanied by a distinct clinical phenotype.     

Does alpine grazing reduce blazing? A landscape test of a widely‐held hypothesis

Abstract ‘Alpine grazing reduces blazing’ is a widely and strongly held view concerning the effects of livestock grazing on fuels, and therefore fire behaviour and impact, in Australia's high country landscapes. As a test of this hypothesis, we examined the patterns of burning across the alpine (treeless) landscapes of the Bogong High Plains in Victoria, following the extensive fires of January 2003. Data were collected from multiple transects, each 3–5 km long, with survey points located randomly at either 50, 200 or 500 m intervals. The transects traversed the major regions of the Bogong High Plains, both grazed and ungrazed. At each point, we recorded whether the point was burnt or unburnt, the vegetation type (closed‐heath, open‐heath, grassland or herbfield), the estimated prefire shrub cover, slope, aspect, and a GPS location. At burnt heathland sites, we recorded the minimum twig diameter (an a posteriori measure of fire severity) in a sample of common shrubs. In total, there were 108 km of transect lines, 419 survey points and 4050 twig measurements, with sample points equally distributed across grazed and ungrazed country. The occurrence of fire (i.e. burnt or unburnt) in grazed and ungrazed areas was analysed by logistic regression; the variation in twig diameters by anova . Approximately half of all points were burnt. There was no statistically significant difference between grazed and ungrazed areas in the proportion of points burnt. Fire occurrence was determined primarily by vegetation type, with the proportion burnt being 0.87 for closed‐heath, 0.59 for open‐heath, and 0.13 for grassland and all snow‐patch herbfield points unburnt. In both closed‐heath and open‐heath, grazing did not significantly lower the severity of fire, as measured by the diameter of burnt twigs. We interpret the lack of a grazing effect in terms of shrub dynamics (little or no grazing effect on long‐term cover of taller shrubs), diet and behaviour of cattle (herbs and dwarf shrubs eaten; tall shrubs not eaten and closed‐heath vegetation generally avoided), and fuel flammability (shrubs more flammable than grass). Whatever effects livestock grazing may have on vegetation cover, and therefore fuels in alpine landscapes, they are likely to be highly localized, with such effects unlikely to translate into landscape‐scale reduction of fire occurrence or severity. The use of livestock grazing in Australian alpine environments as a fire abatement practice is not justified on scientific grounds.     

Does intraspecific competition promote variation? A test via synthesis

Competitive diversification, that is, when increasing intraspecific competition promotes population niche expansion, is commonly invoked in evolutionary studies and currently plays a central role in how we conceptualize the process of adaptive diversification. Despite the frequency with which this idea is cited, the empirical evidence for the process is somewhat limited, and the findings of these studies have yet to be weighed objectively through synthesis. Here, we sought to fill this gap by reviewing the existing literature and collecting the data necessary to assess the evidence for competition as a diversifying force. Additionally, we sought to test a more recent hypothesis, which suggests that competition can act to both promote and inhibit dietary diversification depending on the degree to which a consumer depletes its resources. The surprising result of this synthesis was that increasing competition did not have a mean positive effect on population‐level diet breadth or the degree of individual specialization. Instead, we found that increasing intraspecific competition had a restricting effect on population‐level diet breadth in as many cases as it had a diversifying effect. This wide disparity in the effect of competition on consumer diet variation was negatively related to a metric for consumer resource depletion. Altogether, these findings call into question a long‐standing assumption of basic evolutionary models and lend some support to recent theoretical predictions. Specifically, these findings support the idea that competition is primarily diversifying for species with a small effect (per unit biomass) on their resources and that resource depletion limits the diversifying effect of competition for consumers with larger ecological effects.     

Does the order of second-line treatment in rheumatoid arthritis matter?

In a prospective study 88 patients, with rheumatoid arthritis who had stopped taking gold, penicillamine, or levamisole were randomly allocated to one of the alternative drugs and followed up for a minimum of one year. Concurrent studies of the effects of gold, penicillamine, and levamisole prescribed in 123 patients as the first second-line drug were used for comparison. No difference in toxicity or efficacy between primary and secondary use of gold or penicillamine was identified. Variation in the toxicity of levamisole could in part be accounted for by changes in the dose regimen over the four years of study. The length of the treatment-free interval between drugs did not influence subsequent development of toxicity. These results suggest that an adverse reaction to one of the three second-line drugs studied should not prejudice the selection of another.     

Does Aging Have a Purpose?

Ideas of proponents and opponents of programmed aging concerning the expediency of this phenomenon for the evolution of living organisms are briefly considered. We think that evolution has no “gerontological” purpose, because the obligate restriction of cell proliferation during the development of multicellular organisms is a factor that “automatically” triggers aging due to the accumulation of various macromolecular lesions in cells as a result of the suppression, or even complete cessation of emergence of new, intact cells. This leads to the “dilution” of stochastic damage (the most important of which is DNA damage) at the level of the entire cellular population. Some additional arguments in favor of the inexpediency of aging for both species and individuals are also listed.     

Craniosynostosis and low middle frequency perceptive deafness in mother and son. A distinct entity?

A distinct entity?: In this report we describe the hitherto unreported association of low and middle frequency perceptive deafness and craniosynostosis in mother and son. The occurrence of hearing loss in the craniosynostosis syndromes is briefly reviewed.