Signatures of Extreme Longevity: A Perspective from Bivalve Molecular Evolution

Among Metazoa, bivalves have the highest lifespan disparity, ranging from 1 to 500+ years, making them an exceptional testing ground to understand mechanisms underlying aging and the evolution of extended longevity. Nevertheless, comparative molecular evolution has been an overlooked approach in this instance. Here, we leveraged transcriptomic resources spanning 30 bivalve species to unravel the signatures of convergent molecular evolution in four long-lived species: Margaritifera margaritifera, Elliptio complanata, Lampsilis siliquoidea, and Arctica islandica (the latter represents the longest-lived noncolonial metazoan known so far). We applied a comprehensive approach-which included inference of convergent dN/dS, convergent positive selection, and convergent amino acid substitution-with a strong focus on the reduction of false positives. Genes with convergent evolution in long-lived bivalves show more physical and functional interactions to each other than expected, suggesting that they are biologically connected; this interaction network is enriched in genes for which a role in longevity has been experimentally supported in other species. This suggests that genes in the network are involved in extended longevity in bivalves and, consequently, that the mechanisms underlying extended longevity are-at least partially-shared across Metazoa. Although we believe that an integration of different genes and pathways is required for the extended longevity phenotype, we highlight the potential central roles of genes involved in cell proliferation control, translational machinery, and response to hypoxia, in lifespan extension

Relaxed selection on male mitochondrial genes in DUI bivalves eases the need for mitonuclear coevolution

Mitonuclear coevolution is an important prerequisite for efficient energy production in eukaryotes. However, many bivalve taxa experience doubly uniparental inheritance (DUI) and have sex-specific mitochondrial (mt) genomes, providing a challenge for mitonuclear coevolution. We examined possible mechanisms to reconcile mitonuclear coevolution with DUI. No nuclear-encoded, sex-specific OXPHOS paralogs were found in the DUI clam Ruditapes philippinarum, refuting OXPHOS paralogy as a solution in this species. It is also unlikely that mt changes causing disruption of nuclear interactions are strongly selected against because sex-specific mt-residues or those under positive selection in M mt genes were not depleted for contacting nuclear-encoded residues. However, M genomes showed consistently higher dN/dS ratios compared to putatively ancestral F genomes in all mt OXPHOS genes and across all DUI species. Further analyses indicated that this was consistently due to relaxed, not positive selection on M vs. F mt OXPHOS genes. Similarly, selection was relaxed on the F genome of DUI species compared to species with strict maternal inheritance. Coupled with recent physiological and molecular evolution studies, we suggest that relaxed selection on M mt function limits the need to maintain mitonuclear interactions in M genomes compared to F genomes. We discuss our findings with regard to OXPHOS function and the origin of DUI

Role of poultry meat in a balanced diet aimed at maintaining health and wellbeing: an Italian consensus document

The relationship between the consumption of meat and health is multifaceted, and it needs to be analyzed in detail, with specific attention to the relevant differences that characterize the effects of the different meat types, as yet considered by only a limited literature. A variable but moderate energy content, highly digestible proteins (with low levels of collagen) of good nutritional quality, unsaturated lipids (mainly found in the skin and easily removed), B-group vitamins (mainly thiamin, vitamin B6, and pantothenic acid), and minerals (like iron, zinc, and copper) make poultry meat a valuable food. Epidemiological studies performed across the world, in highly diverse populations with different food preferences and nutritional habits, provide solid information on the association between poultry consumption, within a balanced diet, and good health. Consumption of poultry meat, as part of a vegetable-rich diet, is associated with a risk reduction of developing overweight and obesity, cardiovascular diseases, and type 2 diabetes mellitus. Also, white meat (and poultry in particular) is considered moderately protective or neutral on cancer risk. The relevance of poultry meat for humans also has been recognized by the UN Food and Agricultural Organization (FAO), who considers this widely available, relatively inexpensive food to be particularly useful in developing countries, where it can help to meet shortfalls in essential nutrients. Moreover, poultry meat consumption also contributes to the overall quality of the diet in specific ages and conditions (prior to conception, during pregnancy up to the end of breastfeeding, during growth, and in the geriatric age) and is suitable for those who have an increased need for calorie and protein compared to the general population

RNAIII-inhibiting Peptide and/or Nisin Inhibit Experimental Vascular Graft Infection with Methicillin-susceptible and Methicillin-resistant Staphylococcus epidermidis

AbstractObjective. To investigate the efficacy of RNAIII-inhibiting peptide (RIP) and nisin as prophylactic agents in a rat model of vascular graft infection.Design. Prospective, randomized, controlled animal study.Materials. Two hundred and twenty adult male Wistar rats. Staphylococcus epidermidis ATCC 12228 and one clinical isolate of methicillin-resistant S. epidermidis. Drugs: RIP, nisin and rifampin.Methods. Graft infections were established in the dorsal subcutaneous tissue by implantation of 1 cm2 sterile Dacron grafts, followed by topical bacterial inoculation: grafts were retrieved at 7 days. The study included a control group (without inoculation) and two series composed of five groups for each staphylococcal strain: one contaminated group that did not receive any antibiotic prophylaxis, three contaminated groups that received grafts soaked with 10 mg/l RIP, 10 mg/l nisin, 10 mg/l rifampin, or RIP+nisin. The main outcome measure was the extent of bacterial at graft harvest.Results. The bacterial counts for methicillin-resistant S. epidermidis on explanted grafts were 6.1±2.8×102, 7.8±3.0×103 and 5.5±2.9×104 for RIP, nisin and rifampin, respectively. RIP and nisin used in combination reduced the bacterial count to <10. The results for S. epidermidis were similar.Conclusions. RIP and nisin could be used in combination to coat medical devices to prevent drug resistant S. epidermidis infections

Quinupristin/dalfopristin Bonding in Combination with Intraperitoneal Antibiotics Prevent Infection of Knitted Polyester Graft Material in a Subcutaneous Rat Pouch Model Infected with Resistant Staphylococcus epidermidis

AbstractObjective: to investigate the efficacy of quinupristin/dalfopristin in the prevention of prosthetic graft infection in a rat subcutaneous pouch model.Methods: graft infections were established in the subcutaneous tissue of 140 male Wistar rats by implantation of Dacron prostheses followed by topical inoculation withStaphylococcus epidermidis with intermediate resistance to glycopeptides. The study included one group without contamination, one contaminated group without prophylaxis, one contaminated group that received 50mg/l quinupristin/dalfopristin-soaked graft, one contaminated group that received 10mg/kg intraperitoneal levofloxacin, one contaminated group that received 3mg/kg intraperitoneal doxycycline, and two contaminated groups that received 50mg/l quinupristin/dalfopristin-soaked plus 10mg/kg intraperitoneal levofloxacin or 3mg/kg intraperitoneal doxycycline. Each group included 20 animals. The grafts were removed after 7 days and evaluated by quantitative culture.Results: quinupristin/dalfopristin showed a significantly higher efficacy than levofloxacin and doxycycline, even though quantitative graft cultures for rats that received only quinupristin/dalfopristin-soaked graft showed bacterial growth. Otherwise, the efficacy of levofloxacin was similar to that of doxycycline. Only the group treated with quinupristin/dalfopristin combined with levofloxacin or doxycycline showed no evidence of staphylococcal infection.Conclusions: quinupristin/dalfopristin as adjunctive topical antibiotic prophylaxis can be useful for the prevention of vascular graft infections caused by staphylococcal strains with high levels of resistance

cranial nerve abnormalities in oculo auriculo vertebral spectrum

BACKGROUND AND PURPOSE: Cranial nerve abnormalities might be observed in hemifacial microsomia and microtia (oculo-auriculo-vertebral spectrum), but the rate, features, and relationship with functional impairment or phenotype severity have not yet been defined. This study aimed at investigating absence/asymmetry, abnormal origin, morphology and course of cranial nerves, and presence/asymmetry of the foramen ovale and inferior alveolar nerve canal in a cohort of oculo-auriculo-vertebral spectrum patients. MATERIALS AND METHODS: Twenty-nine patients with oculo-auriculo-vertebral spectrum (mean age, 7 years; age range, 0.2–31 years; 12 females) underwent brain MR imaging, CT, and neurologic evaluation; 19 patients had a more severe phenotype (Goldenhar syndrome). RESULTS: Cranial nerve abnormalities were detected only in patients with Goldenhar syndrome (17/19, bilaterally in 8) and were involved the second (4/19), third (1/18), fifth (11/19), sixth (8/16), seventh (11/18), and eighth (8/18) cranial nerves. Multiple cranial nerve abnormalities were common (11/17). Eleven patients showed bone foramina abnormalities. Trigeminal and facial nerve dysfunctions were common (44% and 58%, respectively), especially in patients with Goldenhar syndrome. Trigeminal abnormalities showed a good correlation with ipsilateral dysfunction ( P = .018), which further increased when bone foramina abnormalities were included. The facial nerve showed a trend toward correlation with ipsilateral dysfunction ( P = .081). Diplopia was found only in patients with Goldenhar syndrome and was associated with third and sixth cranial nerve abnormalities ( P = .006). CONCLUSIONS: Among patients with oculo-auriculo-vertebral spectrum, cranial nerve morphologic abnormalities are common, correlate with phenotype severity, and often entail a functional impairment. The spectrum of cranial nerve abnormalities appears wider than simple hypo-/aplasia and includes an anomalous cisternal course and partial/complete fusion of diverse cranial nerves. CN : cranial nerve OAVS : oculo-auriculo-vertebral spectru

Search for bioindicators of pollution in the Guanabara Bay: integrations of ecologic patterns

Guanabara Bay, since its discovery, has largely changed with the human occupation causing large amounts of deposited sediment and waste, as well as domestic and industry sewage. Surface sediment was analysed for foraminifera and ostracoda distribution, diversity and dominance studies. These results were compared with TOC analyses aiming the determination of pollution bioindicators. In general, foraminifera dominant species were Ammonia tepida, Buliminella elegantissima and Quinqueloculina seminulum. The foraminifera assemblages presented distinct abundance and diversity values in different regions of the bay. The diversity was higher in the entrance (south) and in the central region than in the north region of the bay. The dominant species, that are characteristic of stressed environments, presented higher values of abundance in the north region. The TOC values increased from south to north regions, and were inversely proportional to foraminifera diversity. The very high TOC values in very polluted areas suggest sediment deposition in anoxic-dysoxic environment. The ostracoda Gen. Cyprideis was dominant and its occurrence increased from south to north region. Occurrence of Callistocythere sigmocostata, Xestoleberis sp., Aurila sp., and Paracypris sp. were restricted to the entrance and central area, indicating a preference for less restricted conditions, like marine conditions. Foraminifera and ostracoda characteristic responses to the environment conditions related high TOC values showed their importance as bioindicators of stressed environments caused by anthropogenic pollution, in the Guanabara Bay.A Baía de Guanabara, desde o seu descobrimento, tem sido bastante modificada pela ocupação humana, causando o acúmulo de grande quantidade de sedimento depositado e lixo, bem como lançamento de esgotos domésticos e industriais. Sedimentos superficiais foram analisados visando o estudo da distribuição, diversidade e dominância de foraminíferos e ostracodes. Estes estudos foram comparados com análises de COT objetivando a determinação de bioindicadores de poluição. Em geral as espécies dominantes de foraminíferos foram Ammonia tepida,Buliminella elegantissima and Quinqueloculina seminulum. As associações de foraminíferos apresentam distintos valores de abundância e diversidade em diferentes regiões da Baía. A diversidade foi mais elevada na entrada (sul) e na região central do que na região norte da Baía. As espécies dominantes, que são características de ambientes sob estresse, apresentaram valores altos de abundância na região norte. Os valores de COT aumentaram da região sul para o norte e foram inversamente proporcionais à diversidade de foraminíferos. O elevados valores de COT em áreas muito poluídas sugerem deposição sedimentar em ambiente anóxico-desóxico. O Gen. Cyprideis, de ostracode, foi dominante e sua ocorrência aumentou da região sul para o norte. A ocorrência de Callistocythere sigmocostata, Xestoleberis sp., Aurila sp. e Paracypris sp. foi estrita à entrada e região central, indicando uma preferência por condições menos restritas, como condições marinhas. As respostas características dos foraminíferos e ostracodes às condições ambientais relacionadas aos elevados valores de COT mostraram sua importância como bioindicadores de ambientes sob estresse causado por poluição antropogênica na Baía de Guanabara

The standard error of measurement is a more appropriate measure of quality for postgraduate medical assessments than is reliability: an analysis of MRCP(UK) examinations

Background: Cronbach's alpha is widely used as the preferred index of reliability for medical postgraduate examinations. A value of 0.8-0.9 is seen by providers and regulators alike as an adequate demonstration of acceptable reliability for any assessment. Of the other statistical parameters, Standard Error of Measurement (SEM) is mainly seen as useful only in determining the accuracy of a pass mark. However the alpha coefficient depends both on SEM and on the ability range (standard deviation, SD) of candidates taking an exam. This study investigated the extent to which the necessarily narrower ability range in candidates taking the second of the three part MRCP(UK) diploma examinations, biases assessment of reliability and SEM.Methods: a) The interrelationships of standard deviation (SD), SEM and reliability were investigated in a Monte Carlo simulation of 10,000 candidates taking a postgraduate examination. b) Reliability and SEM were studied in the MRCP(UK) Part 1 and Part 2 Written Examinations from 2002 to 2008. c) Reliability and SEM were studied in eight Specialty Certificate Examinations introduced in 2008-9.Results: The Monte Carlo simulation showed, as expected, that restricting the range of an assessment only to those who had already passed it, dramatically reduced the reliability but did not affect the SEM of a simulated assessment. The analysis of the MRCP(UK) Part 1 and Part 2 written examinations showed that the MRCP(UK) Part 2 written examination had a lower reliability than the Part 1 examination, but, despite that lower reliability, the Part 2 examination also had a smaller SEM (indicating a more accurate assessment). The Specialty Certificate Examinations had small Ns, and as a result, wide variability in their reliabilities, but SEMs were comparable with MRCP(UK) Part 2.Conclusions: An emphasis upon assessing the quality of assessments primarily in terms of reliability alone can produce a paradoxical and distorted picture, particularly in the situation where a narrower range of candidate ability is an inevitable consequence of being able to take a second part examination only after passing the first part examination. Reliability also shows problems when numbers of candidates in examinations are low and sampling error affects the range of candidate ability. SEM is not subject to such problems; it is therefore a better measure of the quality of an assessment and is recommended for routine use