The early sperm gets the good egg: mating order effects in free spawners

Mating order can have important consequences for the fertilization success of males whose ejaculates compete to fertilize a clutch of eggs. Despite an excellent body of literature on mating-order effects in many animals, they have rarely been considered in marine free-spawning invertebrates, where both sexes release gametes into the water column. In this study, we show that in such organisms, mating order can have profound repercussions for male reproductive success. Using in vitro fertilization for two species of sea urchin we found that the 'fertilization history' of a clutch of eggs strongly influenced the size distribution of unfertilized eggs, and consequently the likelihood that they will be fertilized. Males that had first access to a batch of eggs enjoyed elevated fertilization success because they had privileged access to the largest and therefore most readily fertilizable eggs within a clutch. By contrast, when a male's sperm were exposed to a batch of unfertilized eggs left over from a previous mating event, fertilization rates were reduced, owing to smaller eggs remaining in egg clutches previously exposed to sperm. Because of this size-dependent fertilization, the fertilization history of eggs also strongly influenced the size distribution of offspring, with first-spawning males producing larger, and therefore fitter, offspring. These findings suggest that when there is variation in egg size, mating order will influence not only the quantity but also the quality of offspring sired by competing males.

Can heterogeneity in ventilation be good?

Selection of the optimal positive end-expiratory pressure (PEEP) to avoid ventilator-induced lung injury in patients under mechanical ventilation is still a matter of debate. Many methods are available, but none is considered the gold standard. In the previous issue of Critical Care, Zhao and colleagues applied a method based on electrical impedance tomography to help select the PEEP that minimized ventilation inhomogeneities. Though promising when alveolar collapse and overdistension are present, this method might be misleading in patients with normal lungs.

Labour flexibility and gender in the service sector: A study of employment practices in law and accounting firms

In seeking to increase the flexibility of their use of employee time, employers can pursue strategies based on the employment of casual and part-time workers (numerical flexibility) or strategies based on ad hoc variation of the working hours of permanent employees (working time flexibility). Patterns of flexibility strategies and their implications are examined in the context of a highly feminised sector of work-clerical and administrative employment in law and accounting firms. We consider whether, as is often assumed, working time flexibility strategies are generally better for employees because they avoid the substitution of core, high quality jobs with the peripheral, relatively insecure employment often associated with casualisation. Analysing data drawn from a survey of law and accounting firms, we argue that there are three distinct flexibility strategies adopted by employers, and that the choice of strategy is influenced by the size of the firm and the extent of feminisation. The quality of employment conditions associated with each strategy is investigated through an analysis of the determinants of training provision for clerical and administrative workers. Rather than an expected simple linear relationship between increasing casualisation and decreasing training provision, we find that firm size and feminisation are implicated. Larger firms that tend to employ at least some men and use a combination of working time and numerical flexibility strategies tend to provide more training than the small, more fully feminised firms that tend to opt for either casualisation or working time flexibility strategies. This suggests that, from an employee perspective, working time flexibility may not be as benevolent as is often thought.

Extrahepatic portal vein thrombosis after umbilical catheterization: is it a good choice for Rex shunt?

Background: Extrahepatic portal vein thrombosis (EHPVT) is an important cause of portal hypertension in children. Rex shunt has been used successfully to treat these patients. Methods: We report our experience in 19 infants and children (5 months to 14 years) with HPVT eligible for a mesenteric-portal surgical shunt with left internal jugular vein autograft. Eight children had idiopathic EHPVT, nine had post-umbilical catheterization EHPVT, one had portal vein agenesis, and one had posttransplant EHPVT. Results: It was possible to perform the Rex shunt in all patients except for 8 of 9 cases in the post-umbilical catheterization EHPVT group. A Warren procedure was performed in 4 of those patients and a proximal splenorenal shunt in 1. Current follow-up ranges from 3 to 26 months. Shunt thrombosis occurred in one patient with portal vein agenesis and associated cardiac anomaly. Portal hypertension has significantly improved after surgery. None of our patients have experienced new bleeding episodes until now. Conclusions: The Rex shunt should be considered in the treatment of children with idiopathic EHPVT experiencing repeated gastrointestinal bleeding episodes refractory to endoscopic treatment. Nevertheless, the role of this operation for children with post-umbilical catheterization EHPVT is yet to be clearly evaluated. (C) 2011 Elsevier Inc. All rights reserved.

Can the CAMCOG be a good cognitive test for patients with Alzheimer`s disease with low levels of education?

Background: The Cambridge Cognitive Examination (CAMCOG) is a useful test in screening for Alzheimer`s disease (AD). However, the interpretation of CAMCOG cut-off scores is problematic and reference values are needed for different educational strata. Given the importance of earlier diagnoses of mild dementia, new cut-off values are required which take into account patients with low levels of education. This study aims to evaluate whether the CAMCOG can be used as an accurate screening test among AD patients and normal controls with different educational levels. Methods: Cross-sectional assessment was undertaken of 113 AD and 208 elderly controls with heterogeneous educational levels (group 1: 1-4 years; group 2: 5-8 years; and group 3: >= 9 years) from a geriatric clinic. submitted to a thorough diagnostic evaluation for AD including the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX). Controls had no cognitive or mood complaints. Sensitivity (SE) and specificity (SP) for the CAMCOG in each educational group was assessed with receiver-operator-characteristic (ROC) curves. Results: CAMCOG mean values were lower when education was reduced in both diagnostic groups (controls - group 1: 87; group 2: 91; group 3: 96; AD - group 1: 63; group 2: 62; group 3: 77). Cutoff scores for the three education groups were 79, 80 and 90, respectively. SE and SP varied among the groups (group 1: 88.1% and 83.5%; group 2: 84.6% and 96%; group 3: 70.8% and 90%). Conclusion: The CAMCOG can be used as a cognitive test for patients with low educational level with good accuracy. Patients with higher education showed lower scores than previously reported.

Isoforms of hyaluronidases can be a predictor of a prostate cancer of good prognosis

Introduction: Hyaluronidases (HAases) are enzymes related to cancer progression. Isoforms of HAases have been described as products of alternative splicing responsible for differences in enzyme activity. The heterogeneity of HAase expression has been identified in tumors and could be related to the differences in their biological behavior. Methods: Thirty-seven patients subjected to radical prostatectomy for prostate cancer were divided into 2 groups for the analyses: Low (<= 6-18) and high (>= 7-19) Gleason score and tumor behavior; recurrence 15 and nonrecurrence 22, mean follow-up 52.6 months. Conclusion: A profile of HAase related to low Gleason score and non-tumor recurrence was characterized by expression of HYAL3-v1, HYAL1-v3, and HYAL3-v2. More studies should be made in order to confirm with larger series. (C) 2009 Elsevier Inc. All rights reserved.

Good surgical outcome in discordant ictal EEG-MRI unilateral mesial temporal sclerosis patients

Purpose:Video electroencephalography (vEEG) monitoring of patients with unilateral mesial temporal sclerosis (uMTS) may show concordant or discordant seizure onset in relation to magnetic resonance imaging (MRI) evidence of MTS. Contralateral seizure usually leads to an indication of invasive monitoring. Contralateral seizure onset on invasive monitoring may contraindicate surgery. We evaluated long-term outcome after anteromesial temporal lobectomy (AMTL) in a consecutive series of uMTS patients with concordant and discordant vEEG findings, uniformly submitted to AMTL on the MRI evidence of MTS side without invasive monitoring. Methods:We compared surgical outcome of all uMTS patients undergoing vEEG monitoring between January 1999 and April 2005 in our service. Discordant cases were defined by at least one seizure onset contralateral to the MRI evidence of MTS. Good surgical outcome was considered as Engel`s class I. We also evaluated ictal SPECT concordance to ictal EEG and surgical outcome. Results:Fifty-four patients had concordant (C) and 22 had discordant (D) scalp EEG and MRI. Surgical outcome was similar in both groups (C = 74% versus D = 86%). Duration of follow-up was comparable in both groups: C = 56.1 +/- 20.7 months versus D = 59.8 +/- 21.2 months (p = 0.83, nonsignificant). Discordant single-photon emission computed tomography (SPECT) results did not influence surgical outcome. Discussion:Surgical outcome was not influenced by contralateral vEEG seizure onset or contralateral increased flow on ictal SPECT. Although vEEG monitoring should still be performed in these patients, to rule out psychogenic seizures and extratemporal seizure onset, a potentially risky procedure such as invasive monitoring may not only not be indicated in this patient population, but may also lead to patients erroneously being denied surgery.