Diversity and genetic structure of the wood ant Formica lugubris in unmanaged forests

Wood ant species show differences in their social structure, especially in the level of polygyny (number of laying queens per nest) and polydomy (number of nest per colony), both within and between species. We demonstrate here for the first time that Formica lugubris displays two different social forms in close proximity in alpine unmanaged forests of the Swiss National Park. The genetic data (7 microsatellite loci) and field data indicate that one population is mostly monogynous to weakly polygynous (r = 0.438) and monodomous, the second one being polygynous (r = 0.113) and polydomous. Within this latter population new nests are founded by budding, leading to the observed high density of nests. These two different social structures, possibly being two expressions of a same continuum, could be explained by several ecological or environmental factors (e.g. habitat saturation, resource competition) and also historical effects.

The release of antidiuretic hormone is appropriate in response to hypovolemia and/or sodium administration in children with severe head injury: a trial of lactated Ringer's solution versus hypertonic saline.

We conducted an open, randomized, and prospective study to determine the effect of hypertonic saline on the secretion of antidiuretic hormone (ADH) and aldosterone in children with severe head injury (Glasgow coma scale <8). Thirty-one consecutive patients at a level III pediatric intensive care unit at a children's hospital received either lactated Ringer's solution (Ringer's group, n = 16) or hypertonic saline (Hypertonic Saline group, n = 15) over a 3-day period. Serum ADH levels were significantly larger in the Hypertonic Saline group as compared with the Ringer's group (P = 0.001; analysis of variance) and were correlated to sodium intake (Ringer's group: r = 0.39, R(2) = 0.15, P = 0.02; Hypertonic Saline group: r = 0.42, R(2) = 0.18, P = 0.02) and volume of fluids given IV (Ringer's group: r = 0.38, R(2) = 0.15, P = 0.02; Hypertonic Saline group: r = 0.32, R(2) = 0.1, P = not significant). Correlation of ADH to plasma osmolality was significant if plasma osmolality was >280 mOsm/kg (r = 0.5, R(2) = 0.25, P = 0.06), indicating an osmotic threshold for ADH release. Serum aldosterone levels were larger on the first day than during Days 2 and 3 in both groups and inversely correlated to serum sodium levels only in the Ringer's group (r = -0.55, R(2) = 0.3, P < 0.001). This group received a significantly larger fluid volume on Day 1 (P = 0.05, Mann-Whitney U-test) than did patients in the Hypertonic Saline group, indicating hypovolemia during the first day. Head-injured children have appropriate levels of ADH. They may be hypovolemic during the first day of treatment, especially if they receive lactated Ringer's solution. IMPLICATIONS: In head-injured patients, we recommend fluid restriction to avoid inappropriate secretion of antidiuretic hormone. In a prospective, randomized, and controlled study in 31 children, we were able to show that the antidiuretic hormone levels are appropriate in response to hypovolemia, sodium load, or both.

Is tumour size an underestimated feature in the current TNM system for malignancies of the pancreatic head?

BACKGROUND: As the long-term survival of pancreatic head malignancies remains dismal, efforts have been made for a better patient selection and a tailored treatment. Tumour size could also be used for patient stratification. METHODS: One hundred and fourteen patients underwent a pancreaticoduodenectomy for pancreatic adenocarcinoma, peri-ampullary and biliary cancer stratified according to: ≤20 mm, 21-34 mm, 35-45 mm and >45 mm tumour size. RESULTS: Patients with tumour sizes of ≤20 mm had a N1 rate of 41% and a R1/2 rate of 7%. The median survival was 3.4 years. N1 and R1/2 rates increased to 84% and 31% for tumour sizes of 21-34 mm (P = 0.0002 for N, P = 0.02 for R). The median survival decreased to 1.6 years (P = 0.0003). A further increase in tumour size of 35-45 mm revealed a further increase of N1 and R1/2 rates of 93% (P < 0.0001) and 33%, respectively. The median survival was 1.2 years (P = 0.004). Tumour sizes >45 mm were related to a further decreased median survival of 1.1 years (P = 0.2), whereas N1 and R1/2 rates were 87% and 20%, respectively. DISCUSSION: Tumour size is an important feature of pancreatic head malignancies. A tumour diameter of 20 mm seems to be the cut-off above which an increased rate of incomplete resections and metastatic lymph nodes must be encountered and the median survival is reduced.

Methadone enantiomer plasma levels, CYP2B6, CYP2C19, and CYP2C9 genotypes, and response to treatment.

BACKGROUND AND OBJECTIVE: Recent in vitro studies have suggested an important role of cytochrome P450 (CYP) 2B6 and CYP2C19 in methadone metabolism. We aimed to determine the influence of CYP2B6, CYP2C9, and CYP2C19 genetic polymorphism on methadone pharmacokinetics and on the response to treatment. METHODS: We included 209 patients in methadone maintenance treatment on the basis of their response to treatment and their daily methadone dose. Patients were genotyped for CYP2B6, CYP2C9, and CYP2C19. Steady-state trough and peak (R)-, (S)-, and (R,S)-plasma levels and peak-to-trough plasma level ratios were measured. RESULTS: CYP2B6 genotype influences (S)-methadone and, to a lesser extent, (R)-methadone plasma levels, with the median trough (S)-methadone plasma levels being 105, 122, and 209 ng . kg/mL . mg for the noncarriers of allele *6, heterozygous carriers, and homozygous carriers (*6/*6), respectively (P = .0004). CYP2C9 and CYP2C19 genotypes do not influence methadone plasma levels. Lower peak and trough plasma levels of methadone and higher peak-to-trough ratios were measured in patients considered as nonresponders [median (R,S)-methadone trough plasma levels of 183 and 249 ng . kg/mL . mg (P = .0004) and median peak-to-trough ratios of 1.82 and 1.58 for high-dose nonresponders and high-dose responders, respectively (P = .0003)]. CONCLUSION: Although CYP2B6 influences (S)-methadone plasma levels, given that only (R)-methadone contributes to the opioid effect of this drug, a major influence of CYP2B6 genotype on response to treatment is unlikely and has not been shown in this study. Lower plasma levels of methadone in nonresponders, suggesting a higher clearance, and higher peak-to-trough ratios, suggesting a shorter elimination half-life, are in agreement with the usual clinical measures taken for such patients, which are to increase methadone dosages and to split the daily dose into several intakes.

L'agrégation toxique des protéines: une forme de "delinquance moléculaire" activement combattue dans la cellule par les chaperones moléculaires et les protéases [The toxic aggregation of proteins: a kind of "molecular delinquency" actively fought in the cell by molecular chaperones and proteases]

Under various stresses, mutation-sensitised proteins may spontaneously convert into inactive, aggregation-prone structures, which may be cytotoxic and infectious. In the cell, this new kind of "molecular criminality" is actively fought against by a network of molecular chaperones that can specifically identify, isolate and unfold damaged (delinquent) proteins and favour their subsequent native refolding. Irreversibly damaged molecules unable to natively refold are preferentially "executed" and recycled by proteases. Failing that, they are "imprisoned" within compact amyloids, or "evicted" from the cell. Thus, striking parallels, although of questionable ethical value, exist between protein and human criminality, and between the cellular and social responses to these different types of criminality. Fundamental differences also exist. Whereas programmed death (apoptosis) is the preferred solution chosen by aged and aggregation-stressed cells, collective suicide is seldom an option chosen by lawless human societies. More significantly, there is no clear cellular equivalent for the role of the family and the education system, which are so essential to the proper shaping of functional individuals in the society, and give rise to humanism, that favours crime prevention, reeducation and reinsertion programs over capital punishment. To the cardiologist and transplantation surgeon, the interest of molecular chaperones, in particular of Hsp70, Hsp90 and Hsp27, lays in their ability to inhibit the signalling pathway of programmed cell death. Their induction before and during ischemia, by various treatments and drugs could significantly reduce damages from the post ischemic reperfusion of organs.

Evolutionary implications of polygyny in the Argentine ant, Iridomyrmex humilis (Mayr) (Hymenoptera: Formicidae): an experimental study

A comparison of several physiological parameters of queens of Iridomyrmex humilis in experimental monogynous and polygynous colonies showed that queens in monogynous colonies became heavier, had more developed ovaries and laid about twice as many eggs. Workers in monogynous colonies were more attracted to queens, which therefore probably received more food. This may partially explain the higher weight and fecundity of queens in monogynous colonies of Iridomyrmex humilis and possibly other ant species. In polygynous colonies, queens differed greatly in their fecundity. These differences did not appear to be the result of a dominance hierarchy. These results are discussed from an evolutionary point of view. Two hypotheses of mutualism and colony level selection are proposed as an alternative to kin selection which is unlikely to be the exclusive selective influence in the evolution of polygyny either in I. humilis or in most other ant species.

Hyperuricaemia and gout: state of the art and future perspectives.

Major progress has been made in the past decade in understanding the pathogenesis and treatment of gout. These advances include identification of the genetic and environmental risk factors for gout, recognition that gout is an important risk factor for cardiovascular disease, elucidation of the pathways regulating the acute gout attack and the development of novel therapeutic agents to treat both the acute and chronic phases of the disease. This review summarises these advances and highlights the research agenda for the next decade.

Pancréatite aiguë clinique après chimio-embolisation sélective d'un carcinome hépatocellulaire [Acute clinical pancreatitis following selective transcatheter arterial chemoembolization of hepatocellular carcinoma]

Acute pancreatitis can complicate non-selective transcatheter arterial embolization of hepatocellular carcinoma with an incidence ranging from 1,7% (acute clinical pancreatitis) to 40% (biological pancreatitis). This complication is thought to be related to embolization of extrahepatic arterial collaterals.We report herein a case of acute clinical pancreatitis developing within 24 hours after a second course of selective transcatheter arterial chemo-embolization into the proper hepatic artery. Neither anatomical arterial variation nor particular risk factor for acute pancreatitis could be identified. This complication is unusual after selective arterial embolization. Because it may clinically mimick a postembolization syndrome, dosage of serum pancreatic enzymes should be performed systematically in case of abdominal pain following chemoembolization.

Pronostic à long terme des patients ayant bénéficié d'une thrombolyse au stade aigu de l'infarctus du myocarde [Long-term prognosis for patients undergoing thrombolysis during the acute phase of myocardial infarction]

OBJECTIVE: The objective of this study was to analyse the long-term mortality and morbidity of a group of patients undergoing thrombolysis during the acute phase of myocardial infarction and to determine the factors influencing the prognosis. One hundred and seventy five patients (149 mean and 26 women, mean age: 54 years) were included in a randomized study, comparing the efficacy of 2 thrombolytic substances administered during the acute phase of myocardial infarction. A standard questionnaire was sent to the various attending physicians to follow-up of these 175 patients. RESULTS: The hospital mortality was 5% (9 patients) and 14 patients (9%) died after a mean follow-up of 4.3 +/- 2.1 years. The 5-year actuarial survival was 81%. Fourteen patients (8%) were lost to follow-up and 49 patients (32%) underwent surgical or percutaneous revascularization during follow-up. Revascularized patients had a significantly better survival than non-revascularized patients. The mean left ventricular ejection fraction of patients who died was lower (48% versus 71%) than that of survivors. Patients with an ejection fraction < 40% also had a significantly lower survival (p = 0.01). Patency of the vessel after thrombolysis was associated with a slightly better survival; this difference was not significant. The ejection fraction at 6 month was also significantly higher (60 +/- 10% versus 49 +/- 11%) for patients with a patent artery. Three risk factors for death or reinfarction were identified: age > 65 years at the time of infarction, disease in more than one coronary vessel and absence of angina pectoris before infarction. The probability of a coronary accident varied from 2 to 88% according to the number of risk factors present. At the time of follow-up, 60% of patients presented hypercholesterolaemia versus only 7% before infarction 73% of patients received anticoagulant or antiaggregant treatment and 81% of patients were asymptomatic. CONCLUSION: The mortality and the acute and long-term morbidity of myocardial infarction remain high, as only 34% of our patients did not develop any events during follow-up, despite serious medical management and follow-up. The ejection fraction has an important prognostic value. Patient management should take the abovementioned risk factors into account.

Distal trisomy 14 (q24 --> qter) and aorto-pulmonary window: a case report and review of the literature.

A newborn female with partial trisomy for the distal part of the long arm of the chromosome 14 (14q24 --> qter) resulting from a paternal balanced translocation (3;14) is described. We compare her phenotype with eight other individuals with trisomy 14q24 --> qter.

Recent skin injuries in children with motor disabilities.

OBJECTIVE: To determine the frequency of recent skin injuries in children with neuromotor disabilities and its association with disability. DESIGN: Cross-sectional study of 168 children with neuromotor disabilities aged 2-16 years. SETTING: Two outpatient child rehabilitation centres. MAIN OUTCOME MEASURES: Children were classified as unrestricted walkers, restricted walkers or wheelchair dependent. Each participant's body surface was systematically examined for recent skin injuries with the exception of the anal-genital area. RESULTS: The mean age of our sample was 7.8 (SD 3.7) years with a 3:2 male/female ratio. Overall, 64% had cerebral palsy, 17% a neuromuscular disease and 19% other motor disabilities. Participants had on average 5.3 (SD 4.5) recent skin injuries (max 19), of which 2.5 were bruises (SD 3.3, max 16), 2.4 were abrasions, scratches or cuts (SD 3.0, max 16) and 0.4 were pressure lesions (SD 0.8, max 4). There was a significant decrease in the frequency of recent skin injuries and of bruises with increasing severity of motor disability. Most of this variation was accounted for by injuries to the lower limbs. There were no significant effects of gender, learning disabilities or other comorbidities. CONCLUSIONS: Children with neuromotor disabilities present a progressive reduction in the number of skin injuries with decreasing mobility. Therefore, recent skin injuries in this population which are unusual by their number, appearance or distribution, should raise at least the same level of suspicion for physical abuse as in children without disabilities.

Dispersal and Inbreeding Avoidance.

Using a game-theoretical approach, we investigate the dispersal patterns expected if inbreeding avoidance were the only reason for dispersal. The evolutionary outcome is always complete philopatry by one sex. The rate of dispersal by the other sex depends on patch size and mating system, as well as inbreeding and dispersal costs. If such costs are sex independent, then two stable equilibria coexist (male or female philopatry), with symmetric domains of attraction. Which sex disperses is determined entirely by history, genetic drift, and gene flow. An asymmetry in costs makes one domain of attraction extend at the expense of the other. In such a case, the dispersing sex might also be, paradoxically, the one that incurs the higher dispersal costs. As asymmetry increases, one equilibrium eventually disappears, which may result in a sudden evolutionary shift in the identity of the dispersing sex. Our results underline the necessity to control for phylogenetic relationships (e.g., through the use of independent-comparisons methods) when investigating empirical trends in dispersal. Our model also makes quantitative predictions on the rate of dispersal by the dispersing sex and suggests that inbreeding avoidance may only rarely be the sole reason for dispersal.

Extensive (8 to 12 cm2) noncircumferential endoscopic mucosal resection for early esophageal cancer.

Background: Endoscopic mucosal resection (EMR) is an appealing method for treating intramucosal esophageal cancer but must comply with the following stringent requirements: proper preoperative staging, complete resection of the lesion, obtaining a resected specimen for histologic analysis of safety margins, and squamous reepithelialization without stricture formation. Methods: A rigid esophagoscope was created to resect up to 12 cm(2) of esophageal mucosa in a single specimen and at a constant depth through the submucosa. Under visual control, the esophageal mucosa is sucked into a transparent window and resected with a thin diathermy wire loop in 10 seconds. After extensive preclinical studies in a sheep model, this article reports our early experience in humans. Results: Twenty-one hemi-circumferential EMRs were performed for 11 dysplastic Barrett's esophagi and 10 early squamous cell carcinomas with no perforation, one hemorrhage controlled by embolization of the left gastric artery, and one incomplete resection. Deep safety margins were clear in 19 of 21 resected specimens (2 patients, unfit for operations, had submucosal invasion of squamous cell carcinoma and adenocarcinoma, respectively). Lateral margins were not clear by definition in 7 circumferential Barrett's esophagi, but were clear in 4 incomplete Barrett's esophagi and 10 early squamous cell carcinomas. Conclusions: Large EMRs of 12 cm(2) can safely be performed at the submucosal level in the esophagus. Although feasible in one session, circumferential EMR in humans is not yet advisable because of the risk of stricture formation during the healing phase. The rate of complications of this series of 21 EMRs in humans is acceptable. (Ann Thorac Surg 2010; 89: S2151-5) (C) 2010 by The Society of Thoracic Surgeons