BDNF Val66Met genotype modulates the effect of childhood adversity on subgenual anterior cingulate cortex volume in healthy subjects

According to the neurotrophic hypothesis of depression, stress can lead to brain atrophy by modifying brain-derived neurotrophic factor (BDNF) levels. Given that BDNF secretion is affected by a common polymorphism (rs6265, Val66Met), which also is associated with depression, we investigated whether this polymorphism modifies the effect of childhood adversity (CA) on local gray matter (GM) volume in depression-relevant brain regions, using data from two large cohorts of healthy subjects. We included 568 healthy volunteers (aged 18-50 years, 63% female) in our study, for whom complete data were available, with magnetic resonance imaging data at 1.5 Tesla (N=275) or 3 Tesla (N=293). We used a whole brain optimized voxel-based morphometry (VBM) approach assessing genotype-dependent GM differences, with focus on the amygdala, hippocampus and medial prefrontal cortex (PFC; including anterior cingulate cortex (ACC) and orbitomedial PFC). CA was assessed using a validated questionnaire. In both cohorts, we found that BDNF methionine (Met)-allele carriers with a history of CA had significantly less GM in subgenual ACC (P<0.05) compared with Met-allele carriers without CA and Val/Val homozygotes with CA. No differences were found in hippocampus, amygdala and orbitomedial PFC. On the basis of our findings, we conclude that BDNF Met-allele carriers are particularly sensitive to CA. Given the key role of the subgenual ACC in emotion regulation, this finding provides an important mechanistic link between stress and BDNF on one hand and mood impairments on the other hand.

NOTES, hybrid NOTES, NOTES-assisted kidney surgery: what has been achieved so far?

With improved technologies and the development of new techniques, has emerged the concept of "scarless surgery" in an attempt to treat certain diseases obviating the need for incisions to access the peritoneal cavity, resulting in direct benefit to patients and assuming an improvement in quality of life and offering an advantage over conventional laparoscopy. Laparoendoscopic single-site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES) are evolutions of laparoscopy, and they are complementary techniques that should be included in this new concept. NOTES is an emerging surgical modality that uses endoscopic instruments through hollow viscera to enter the peritoneal cavity and allow surgical procedures without incisions. The NOTES procedure may provide additional benefits when compared with current minimally invasive procedures. Potential advantages include no skin incisions, improved cosmetic result, reduced postoperative pain, diminished risk of postoperative hernias, and earlier recovery. NOTES surgery has still some inconvenient regarding instrumentals, viewing orientation, control of complications. Attempts to overcome the current limitations of the technique have given rise to the concept of hybrid NOTES, which is performed with the assistance of transabdominal ports for the use of conventional laparoscopy equipment. NOTES is a very promising technique although further investigation is necessary until implementing NOTES surgery in the common clinical practice.

Amygdala to hippocampal volume ratio is associated with negative memory bias in healthy subjects

BACKGROUND

Negative memory bias is thought to be one of the main cognitive risk and maintenance factors for depression, but its neural substrates are largely unknown. Here, we studied whether memory bias is related to amygdala and hippocampal volume, two structures that are critical for emotional memory processes and that show consistent volume alterations in depression.

METHOD

Structural magnetic resonance imaging (MRI) was carried out in 272 healthy participants (62% female, 18-50 years old). All images were acquired on 1.5 T Siemens MRI scanners. Automatic segmentation of amygdala and hippocampus was performed using the FIRST module of FSL. Negative memory bias was assessed by the self-referent encoding/evaluation test.

RESULTS

Negative memory bias was associated with larger amygdala (p=0.042) and smaller hippocampal (p=0.029) volumes. In additional analyses, we found that, compared with the associations found with hippocampus and amygdala volume separately, a stronger association was found between negative memory bias and the ratio of amygdala:hippocampus volume (p=0.021).

CONCLUSIONS

In non-depressed subjects we found that larger amygdala and smaller hippocampal volumes are associated with negative memory bias. This suggests that an increased amygdala:hippocampus volume ratio plays a role in cognitive vulnerability often seen in individuals with high risk for depression and that these structural brain differences may pre-date the onset of depression.

Seroprevalence and risk factors associated with Visna/Maedi virus in semi-intensive lamb-producing flocks in northwestern Spain

A cross-sectional study was carried out to determine Visna/Maedi virus (VMV) seroprevalence and risk factors in semi-intensive lamb-producing flocks as a prelude to establishing a monitoring program in northwestern (NW) Spain. A total of 15,155 serum samples were taken from 78 commercial flocks and were submitted to an indirect VMV ELISA. Association between potential risk factors and seroprevalence at the flock level was assessed using a multivariable logistic regression model. A Generalized Estimating Equations (GEE) model and Exhaustive Chi-squared Automatic Interaction Detector (CHAID) were used to determine the seropositivity against VMV at the individual animal level. Individual seropositivity was 24.8% while 52.6% of the flocks examined had a true seroprevalence ≥1%. Flock size and introduction of new animals in the flock were significantly associated with seropositivity at the flock level. Flock size, sheep-goat contact, type of housing of lambs prior to weaning and age were significantly associated with individual VMV seropositivity. Confinement of lambs in preweaning lamb groups and high sheep-goat contact, regardless of the low number of goats per flock, were risk factors associated with individual VMV seropositivity, suggesting that these two factors are crucial for VMV control in semi-intensive lamb-producing flocks. These factors should be considered for developing more efficient strategies that will reduce the rate of VMV transmission.

Neural basis of emotion recognition deficits in first-episode major depression

BACKGROUND

Depressed individuals demonstrate a poorer ability to recognize the emotions of others, which could contribute to difficulties in interpersonal behaviour. This emotion recognition deficit appears related to the depressive state and is particularly pronounced when emotions are labelled semantically. Here, we investigated its neural basis by comparing emotion recognition processing between depressed, recovered and healthy individuals.

METHOD

Medication-naive patients with a first major depressive episode, medication-free patients who had recovered from a first episode, and a group of matched healthy individuals participated. They were requested to identify the emotion of angry and fearful face stimuli, either by matching them to other emotional faces on a perceptual basis or by matching them to a semantic label, while their brain activity was measured with functional magnetic resonance imaging.

RESULTS

The depressed individuals performed worse than recovered and healthy individuals on the emotion-labelling but not the emotion-matching task. The labelling deficit was related to increased recruitment of the right amygdala, left inferior frontal gyrus and anterior cingulate cortex.

CONCLUSIONS

Deficits in semantic labelling of negative emotions are related to increased activation in specific brain regions and these abnormalities are mood state-dependent. These results indicate that accessing semantic knowledge about negative information triggers increased amygdala and left inferior frontal gyrus processing, which subsequently impairs task-relevant behaviour. We propose that this may reflect the activation of negative schemas.

Perceived threat predicts the neural sequelae of combat stress

Exposure to severe stressors increases the risk for psychiatric disorders in vulnerable individuals, but can lead to positive outcomes for others. However, it remains unknown how severe stress affects neural functioning in humans and what factors mediate individual differences in the neural sequelae of stress. The amygdala is a key brain region involved in threat detection and fear regulation, and previous animal studies have suggested that stress sensitizes amygdala responsivity and reduces its regulation by the prefrontal cortex. In this study, we used a prospective design to investigate the consequences of severe stress in soldiers before and after deployment to a combat zone. We found that combat stress increased amygdala and insula reactivity to biologically salient stimuli across the group of combat-exposed individuals. In contrast, its influence on amygdala coupling with the insula and dorsal anterior cingulate cortex was dependent on perceived threat, rather than actual exposure, suggesting that threat appraisal affects interoceptive awareness and amygdala regulation. Our results demonstrate that combat stress has sustained consequences on neural responsivity, and suggest a key role for the appraisal of threat on an amygdala-centered neural network in the aftermath of severe stress.

Tick infestation (Acari: Ixodidae) in roe deer (Capreolus capreolus) from northwestern Spain: population dynamics and risk stratification

During the 2007 and 2008 hunting seasons (April-October) the skin of 367 roe deer (Capreolus capreolus L.), hunted in different preserves from Galicia (Northwestern Spain), were examined for ticks (Acari: Ixodidae). The overall prevalence of infestation by ticks was 83.1%. The predominant species was Ixodes ricinus (83.1%), whereas a single Dermacentor marginatus specimen appeared in one roe deer. All developmental stages of I. ricinus were found parasitizing roe deer, the adults being the most frequent (82.2%), followed by nymphs (45.6%) and larvae (27.2%). The mean intensity of infestation by I. ricinus was 43.2 ± 49.85; most of them were adults (30.7 ± 31.64) and in a lesser extend nymphs (16.9 ± 24.74) and larvae (10.7 ± 29.90). Ixodes ricinus was present all over the study with percentages that oscillated between 100% in spring and 57.4% in autumn. CHAID algorithm showed the sex of roe deer as the most influential factor in tick prevalence, followed by the climatic area. The different developmental stages of I. ricinus were more frequent in males than in females, and the prevalence of adults and larvae were higher in roe deer from coastal areas than in those from mountainous and central areas, whereas nymphs were more frequent in mountainous areas. Host age and density were not determinants for tick infestation. Our results confirm that roe deer are important hosts for I. ricinus in northwestern Spain, serving as a vehicle for the geographic distribution of these ticks.

The immediate effects of diacutaneous fibrolysis on pain and mobility in patients suffering from painful shoulder: a randomized placebo-controlled pilot study

OBJECTIVES

To describe the immediate effects of diacutaneous fibrolysis on pain and mobility in patients suffering from painful shoulder, and to assess the ability of the placebo technique to blind participants to group allocation.

DESIGN

A double-blind before-after randomized placebo-controlled pilot study.

SETTING

Two public centres of Primary Health Care of the Spanish National Health System.

PARTICIPANTS

Fifty patients (29 women, 21 men) with a diagnosis of painful shoulder of subacromial origin were included.

INTERVENTION

Participants were randomly allocated to one of two groups. The intervention group (N = 25) was actually treated with diacutaneous fibrolysis, while the placebo group (N = 25) was treated with placebo diacutaneous fibrolysis.

MEASUREMENTS

Active range of motion (flexion, abduction, extension, external and internal rotation) and pain intensity in the hand-behind-back position were measured. Participants were also asked about their perception in terms of comfort of the technique and results obtained.

RESULTS

Between-groups differences were significant in flexion (mean 11.4 degrees; 95% confidence interval (CI) 5.7-17.1), abduction (mean 7.2 degrees; 95% CI 2.0-12.5) and internal rotation movements (mean 3.1 cm; 95% CI 0.1-6.1). There were no significant differences between groups in pain intensity, extension or external rotation movements. The placebo technique showed its ability to blind participants to group allocation. None of the participants suffered any adverse effects from diacutaneous fibrolysis.

CONCLUSION

Diacutaneous fibrolysis may be an effective and safe therapeutic option to improve active range of motion in patients suffering from painful shoulder.

Efficacy of anthelminthic control programs against natural Muellerius capillaris infection in sheep in the north-west of Spain. Effect on blood gases and pH in venous blood samples

The field efficacy of a single dose treatment against natural M. capillaris infection using different anthelmintic drugs, extensively employed in ovine parasite control programs in Galicia (N.W. Spain), and the effect of protostrongylid infection on ovine respiratory functions, were evaluated. Five groups (n = 5) of ewes were used in this study; animals were treated with injectable ivermectin 10.2 mg/kg), levamisole (7.5 mg/kg) and albendazole (5 mg/kg) and monitored at 0, 7, 21, 42 and 63 days posttreatment (d.p.t.) by enumeration of the lungworm larvae per gram of faeces (l.p.g.) and determination of gas tension and pH in venous blood using an i-Stat portable clinical analyzer. No statistical difference was found either in larval elimination between untreated and treated groups or in the reduction in larval counts in all of the treated groups. A significant increase in partial oxygen tension (pO2) and saturation (sO2) between day 0 and 7 p.t. was observed in all treated animals. These values decreased significantly at day 21 to previous levels. There were no statistical differences in blood gases between uninfected and treated groups. We can conclude that under Galician field conditions, parasitic control programs are not totally effective against M. capillaris infection.

422 GENERATION OF REPORTER TRANSGENIC MICE FOR THE CHEMOKINE CXCL2 USING TWO DIFFERENT DNA CONCENTRATIONS

Transgenic mice have important implications in biomedicine, and are widely employed to understand gene functions and their regulation. The improvement of transgenic efficiency is relevant because of the low rate of success for this technology. CXCL2 is a chemokine secreted by macrophages and epithelial cells under proinflammatory stimulus of the innate immune response such as bacterial endotoxins. The main effect of CXCL2 is the recruitment of neutrophils to the site of production to fight infections. The objective of this study was to evaluate the effect of 2 DNA concentrations in the efficiency of the transgenesis process. To this aim we used a luciferase reporter under the control of CXCL2 promoter for the generation of a transgenic line to report activation of innate immune response. A total of 1727 1-cell embryos were divided into 2 experimental groups to be microinjected with 0.5 or 1.0 ng μL-1 of DNA in 25 sessions. Three-week-old B6SJL F1 females (n = 131) were superovulated with 5 IU of eCG i.p. (Novormon, Syntex, Buenos Aires, Argentina) and 5 IU of hCG i.p. (Ovusyn, Syntex) 46 h later, and mated with B6SJL F1 stud males. At the moment of hCG treatment, foster females were mated with vasectomized males to induce pseudogestation. Donor females were euthanized by cervical dislocation 20 h after hCG treatment, and embryos were recovered from the ampulla, denuded in 300 μg mL-1 hyaluronidase (Sigma, St. Louis, MO, USA) and incubated at 37°C with 5% CO2, in drops of M16 media (Sigma) under mineral oil, until microinjection. DNA construction consisted of the luciferase reporter gene under the control of the murine CXCL2 gene promoter. Embryos were microinjected into 1 pronucleus under an inverted microscope (Nikon, NY, USA) using glass microtools and mechanic micromanipulators (Eppendorf, Hamburg, Germany). Intact/injected embryos were assessed 30 min after microinjection. Fifteen to 20 embryos per foster female were transferred in both oviducts. Birth rate, survival of pups at Day 7 after birth, number of transgenic pups assessed by standard PCR, and overall transgenic efficiency was registered for each group. Data were analyzed by Yates-corrected chi-square test. No statistical differences were founded except for a higher number of pups alive/embryo transferred in the lower DNA concentration, suggesting the advantage of using 0.5 ng μL-1 v. 1.0 ng μL-1. Table 1.Effect of DNA concentration in the generation of CXCL2-luc transgenic mice

Degradation of bisphenol A in water by Fe(III)/UVA and Fe(III)/polycarboxylate/UVA photocatalysis

The photodegradation of the endocrine disrupting chemical Bisphenol A (BPA) under UVA irradiation in the presence of Fe(III) or Fe(III)-polycarboxylate systems was studied. The effect of Fe(III) concentration, aqueous pH and the presence of four carboxylic acids (oxalic, malic, tartaric and citric) were investigated. The Fe(III)/UVA system was able to effectively degrade BPA at pH 3 but failed at pH > 4. At any rate, no mineralization of BPA was achieved with the Fe(III)/UVA system. The presence of carboxylic acids greatly enhanced the BPA degradation rate because of the formation of photoactive Fe(III)-polycarboxylate complexes. Aqueous pH in the 3-7 range exerted a negative effect on the BPA degradation rate and TOC conversion in the presence of oxalic, malic and tartaric acids. Only slight effect of pH was observed in the presence of citric acid, being the BPA degradation rate significant even at pH 7.

Differential effects of glucocorticoids in the establishment and maintenance of endotoxin tolerance

Gram-negative infections can result in endotoxic shock, which is the most common cause of death in intensive care units. Most of the undesirable effects in sepsis and septic shock have been ascribed to lipopolysaccharide (LPS), a normal constituent of the bacterial wall. The response to LPS involves rapid secretion of proinflammatory cytokines [tumour necrosis factor-alpha, interleukin (IL)-1, IL-6, IL-8, interferon-gamma] and the concomitant induction of anti-inflammatory mediators such as IL-10 and transforming growth factor-beta and glucocorticoids (GC), which render the host temporarily refractory to subsequent lethal doses of LPS challenge in a process known as LPS or endotoxin tolerance. Although protective from the development of sepsis or systemic inflammation, endotoxin tolerance has also been pointed out as the principal cause of the non-specific immunosuppression described in these patients. In this report we demonstrate, using a mouse model, that while the maintenance of tolerance is dependent upon GC, the establishment of tolerance by LPS could be inhibited by dexamethasone (Dex), a synthetic GC. Conversely, we demonstrated that mifepristone (RU486), a known GC receptor antagonist, was capable of inducing a transient and reversible disruption of endotoxin tolerance, also permitting partial restoration of the humoral immune response in LPS tolerant/immunosuppressed mice. These results are encouraging for the management of immunosuppression in sepsis and/or non-infectious shock, and deserve further investigation in the future.

Performance of VITEK-2 Compact and overnight MicroScan panels for direct identification and susceptibility testing of Gram-negative bacilli from positive FAN BacT/ALERT blood culture bottles

We describe the reliability of the VITEK-2 Compact and overnight MicroScan panels for direct identification and susceptibility testing from the BacT/ALERT blood culture system when using FAN (FA and FN) bottles. A simple procedure, in two centrifugation steps, was designed to remove the charcoal particles present in FA and FN bottles. A total of 113 positive blood cultures showing Gram-negative rods were investigated. Enterobacteriaceae were isolated in 104 cases, and Pseudomonas aeruginosa in nine. The MicroScan system correctly identified 106 (93.8%) of the 113 isolates. The seven identificaction errors included P. aeruginosa (three), Enterobacter cloacae (one), Escherichia coli (one), Klebsiella oxytoca (one), and Klebsiella pneumoniae (one). The VITEK-2 system correctly identified 109 (96.5%) of the 113 samples obtained directly from the blood culture bottles. The four unidentified isolates were Enterobacter cloacae (two), Escherichia coli (one), and P. aeruginosa (one). MicroScan yielded 4/779 (0.5%) very major errors and 28/2825 (0.9%) minor errors. VITEK-2 yielded 2/550 (0.36%) very major errors, 1/1718 (0.05%) major error, and 32/2373 (1.3%) minor errors. Both systems provided excellent identification (correlation of >90%) and susceptibility (correlation of >98%) results. The average times required to obtain identification and susceptibility results using the direct test applied to the VITEK-2 Compact system were 4.57 +/- 1.37 h and 6.52 +/- 1.64 h, respectively. The VITEK-2 compact system provided results on the same day that the blood culture was found to be positive.

Seroprevalence of Toxoplasma gondii and Neospora caninum in wild and domestic ruminants sharing pastures in Galicia (Northwest Spain)

The prevalence of antibodies to the protozoan parasites Toxoplasma gondii and Neospora caninum were investigated by the direct agglutination test (DAT) and cELISA, respectively, in 160 roe deer (Capreolus capreolus), 177 sheep and 178 cattle sharing pastures in Galicia (Northwest Spain). The seroprevalence for T. gondii was 13.7% in roe deer, 57% in sheep and 7.3% in cattle. The seroprevalence for N. canimum was 6.8%, 10.1% and 24.1% in roe deer, sheep and cattle, respectively. Statistically significant differences were observed between sheep and the other species for T. gondii and between cattle and the other ruminants for N. caninum. Only 19/515 animals were positive for both, T. gondii and N. caninum. Statistically significant differences were observed among different geographical areas for T. gondii but not for Neospora, seroprevalence being higher in the coastal area lower than in other areas. This study reveals a widespread exposure to T. gondii in Galician ruminants, and therefore, those species, particularly sheep, should be regarded as a potential source of infection for humans.

CDKN2A mutations in melanoma families from Uruguay

BACKGROUND

Familial melanoma, a cluster of several cases within a single family, accounts for approximately 10% of cases of melanoma. Hereditary melanoma is defined as two or more first-degree relatives having melanoma. A member of a melanoma-prone family has a 35-70-fold increased relative risk of developing a melanoma. Genetic susceptibility is linked to the major susceptibility genes CDKN2A and CDK4, and the minor susceptibility gene MC1R.

OBJECTIVES

To determine the clinical and genetic characteristics of cutaneous melanoma in melanoma-prone families from Uruguay.

METHODS

We studied 13 individuals from six melanoma-prone families living in Uruguay. Phenotype, familial and personal history were recorded. Molecular screening of CDKN2A and CDK4 was done by polymerase chain reaction-single strand conformational polymorphism analysis. The MC1R gene was sequenced.

RESULTS

Mutations in CDKN2A were detected in five of six families: c.-34G>T, p.G101W and p.E88X. A novel germline mutation p.E88X, associated with hereditary melanoma in two unrelated families, is described. We hypothesize that a founder effect occurred probably in the Mediterranean region. No mutations in CDK4 were detected. Six different MC1R variants, all previously reported, were present in Uruguayan families.

CONCLUSIONS

The overall rate of deleterious CDKN2A mutations in our familial melanoma pedigrees, even though the sample size is small, was considerably higher (83%) than the often quoted range.