[Evaluation of the variability in the susceptibility of Acinetobacter baumannii to tigecycline in the same medium with two methods of quantitative diffusion different commercial]

INTRODUCTION

Tigecycline may be a therapeutic alternative for the control of multidrug-resistant Acinetobacter baumannii, although there is no consensus on the cutoffs or susceptibility to the variability of the minimum inhibitory concentration (MIC) according to the culture medium and strips for the antibiogram against this microorganism by quantitative diffusion method. Therefore, the objective was to verify this variability and propose epsilometer test strip that more closely resemble to the standard method.

MATERIAL AND METHODS

38 strains of A. baumannii were selected and evaluated their susceptibility to tigecycline with two different commercial strips (E-TEST and Liofilchem). MICs were compared with those obtained by the standard technique of microdilution broth.

RESULTS

MICs obtained by the Liofilchem strip were more similar to standard method than those obtained by E-TEST strips.

CONCLUSION

In the two studied strips, higher MICs to those obtained by the standard method were observed leading to false-positive tigecicline resistance in many cases. However, the Liofilchem strip showed the results more closely resemble to the standard method.

Trends in emergent inguinal hernia surgery in Olmsted County, MN: a population-based study

BACKGROUND

Evidence suggests that watchful waiting of inguinal hernias (IH) is safe because the risk of acute strangulation requiring an emergent repair is low. However, population-based incidence rates are lacking, and it is unknown whether the incidence of emergent inguinal hernia repairs (IHR) has changed over time.

STUDY DESIGN

A retrospective review of all IHR performed on adult residents of Olmsted County, Minnesota from 1989 to 2008 was performed using the Rochester epidemiology project, a record-linkage system that covers more than 97 % of the population (2010 US Census = 146,466). Incidence rates/100,000 person-years were calculated, and trends over time were evaluated using Poisson regression.

RESULTS

A total of 4,026 IHR were performed on 3,599 patients; 136 repairs (3.8 %) were emergent. Of these, 19 patients (14 %) had bowel resection and three (2 %) died within 30 days of the repair. Rates/100,000 person-years yielded an overall incidence of 7.6 for emergent IHR and 200.0 for elective IHR. Emergent IHR rates increased with age. Overall emergent IHR rates declined from 18.2 to 12.4 in men and from 6.4 to 2.4 in women from 1989 to 2008 (p > 0.05). Older age, obesity, a high ASA risk score, a femoral and/or a recurrent hernia were more likely to be associated with an emergent IHR (all p ≤ 0.05).

CONCLUSION

The incidence of emergent IHR is low. This risk has decreased over the past 20 years. However, patients who are either ≥70 years old, obese, with a high ASA score, or with a femoral or recurrent hernias are more likely to require an emergent IHR and could benefit from elective operative intervention if deemed adequate surgical candidates.

Dehydroepiandrosterone prevents the aggregation of platelets obtained from postmenopausal women with type 2 diabetes mellitus through the activation of the PKC/eNOS/NO pathway

The steroid hormone dehydroepiandrosterone (DHEA), suggested to be a cardioprotector, prevents platelet aggregation in healthy humans. This hormone is reduced in postmenopausal women by 60% of its normal value. Platelets in patients with type 2 diabetes (T2D) are more sensitive to aggregation, which has been attributed to a reduced ability to produce nitric oxide (NO). In light of these precedents and considering that DHEA is able to increase the production of NO in cultured endothelial cells, we suggest that DHEA prevents the aggregation of platelet from postmenopausal women with T2D through the activation of PKC/eNOS/NO/cGMP pathway. To determine the effect of DHEA in platelet aggregation, platelet-rich plasma (PRP) obtained from postmenopausal women with T2D was preincubated with DHEA, and aggregation induced by ADP was determined in the presence or absence of L-NNA (LNG-nitroarginine), Rottlerin, NOS, or PKC delta inhibitors, respectively. Platelet NO production was measured with the fluorescent probe DAF2DA and eNOS activation was determined by Western blot, using an anti-p-eNOS (ser 1177) antibody. DHEA 1) prevented platelet aggregation by 40% compared to control, 2) increased NO production by 63%, 3) increased p-eNOS (phosphorylated endothelial nitric oxide synthase) levels, and 4) increased cGMP production. These effects were reduced in the presence of L-NNA or Rottlerin. DHEA prevents platelet aggregation induced by ADP. This effect is mediated by the activation of the PKCδ/eNOS/NO/cGMP pathway. Our results suggest that DHEA could be considered to be a potential therapeutic tool in the prevention of atherothrombotic processes in postmenopausal women with T2D.

Is on-demand treatment effective in patients with severe haemophilia?

On-demand therapy enables stopping haemorrhages rapidly, reducing joint pain and restoring joint mobility, but does not prevent the beginning and subsequent development of haemophilic arthropathy. The main objective of this study was to identify the clinical and orthopaedic status of severe haemophilic patients with bleeding phenotype receiving on-demand treatment in Spain. We conducted an epidemiological, observational, retrospective study, recruiting 167 patients from 36 centres (92% of them with haemophilia A), median age at enrolment of 35 years. Forty per cent of the patients received a combination of on-demand and short-term prophylaxis regimen; the rest was under on-demand treatment. One hundred and forty-five patients (87%) reported at least one bleeding episode and 22 (13%) of the biologically severe patients had no bleeding phenotype. Seventy-one per cent of the studied population presented established haemophilic arthropathy, reaching 80% if we exclude patients without bleeding phenotype. Forty-three per cent of these patients had one or two joints affected, 28% of them had three or four affected joints, 20% reported five or six affected joints and 9% more than six injured joints. An increase in established haemophilic arthropathy with age was observed. Forty-six patients underwent orthopaedic surgery at least once. These data show that on-demand therapy is not effective in preventing the development of haemophilic arthropathy in severe haemophilic population with bleeding phenotype. Therefore, we suggest that the optimal treatment in these patients should be based on prophylaxis. We recommend analysing the reasons for ending prophylaxis, in case its reinstatement should be necessary.

Hypovitaminosis D as a risk factor of hip fracture severity

SUMMARY

In a cross-sectional study including 324 patients older than 65 years admitted to our hospital for osteoporotic hip fracture, we found that those patients with a more severe vitamin D deficiency had more severe osteoporotic hip fractures (Garden grades III-IV and Kyle III-IV).

INTRODUCTION

To identify possible differences in baseline characteristics of patients with different types of osteoporotic hip fracture.

METHODS

Cross-sectional study including consecutive individuals over 65 admitted to our hospital for osteoporotic hip fracture over a year. Demographic data, fracture type, comorbidities, history of osteoporosis, functional capacity, nutritional status and vitamin D storage were evaluated.

RESULTS

We included 324 patients (83 ± 7 years, 80% women). Two hundred sixteen patients (67%) had vitamin D deficiency (25OHD3 <25 ng/ml). In patients with severe femoral neck or intertrochanteric fractures (Garden III-IV and Kyle III-IV), vitamin D deficiency was more frequent (74%) and severe (25OHD3 20 ± 15 ng/ml) than in patients with less severe fractures (57%, 25OHD3 26 ± 21 ng/ml). Forty-three percent of patients had previous fractures. Only 15% of patients had been previously diagnosed with osteoporosis and 10% were receiving treatment. Patients receiving vitamin D supplements have higher 20OHD3 levels and less severe fractures.

CONCLUSIONS

Although vitamin D levels are not different between patients with intracapsular or extracapsular hip fractures, a more severe vitamin D deficiency seems to be associated to more severe osteoporotic hip fractures. A prior vitamin D supplementation could avoid a higher severity of these fractures.

Clinical validation of the European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE) II criteria in an open-access unit: a prospective study

BACKGROUND AND STUDY AIMS

The European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE I) criteria were recently updated (EPAGE II), but no prospective studies have used these criteria in clinical practice. The aim of the current study was to validate the EPAGE II criteria in an open-access endoscopy unit.

PATIENTS AND METHODS

A prospective observational study was conducted in an open-access endoscopy unit at a tertiary care referral center. Consecutive outpatients (n = 1004; mean age 58.9 ± 13.1 years; 45 % men) were referred for diagnostic colonoscopy between September 2009 and February 2010. The appropriateness of colonoscopy was assessed based on EPAGE II criteria, and the relationship between appropriateness and both referral doctor and detection of significant lesions was examined. The effectiveness of EPAGE II criteria in assessing appropriateness was measured by means of sensitivity, specificity, and positive and negative predictive values for detecting significant lesions.

RESULTS

Colonoscopic cecal intubation was achieved in 956 patients (95.2 %). Most referral doctors were gastroenterologists (58.0 %) and the most common indication was colorectal cancer (CRC) screening (35.2 %). EPAGE II criteria were applicable in 968 patients (96.4 %); of these patients, the indication was appropriate in 778 (80.4 %), inappropriate in 102 (10.5 %), and uncertain in 88 (9.1 %). Patients with appropriate or uncertain indications based on EPAGE II criteria had more relevant endoscopic findings than those with inappropriate indications (38.8 % vs. 24.5 %; OR 1.95, 95 %CI 1.22 - 3.13; P < 0.005). Sensitivity and negative predictive value of EPAGE II criteria for detecting significant lesions were 93.1 % (95 %CI 90 % - 96 %) and 75.5 % (95 %CI 67 % - 84 %), respectively, whereas for advanced neoplastic lesions these values were 98.0 % (95 %CI 95 % - 100 %) and 98.0 % (95 % CI 95 % - 100 %), respectively. Adherence to EPAGE II recommendations was an independent predictor of finding a significant lesion (OR 1.93, 95 %CI 1.20 - 3.11; P = 0.007).

CONCLUSIONS

EPAGE II is a simple, valid score for detecting inappropriate colonoscopies in clinical practice.

Efficacy and safety of non-operative management of blunt liver trauma

BACKGROUND

The liver is the most frequently affected organ during blunt abdominal trauma. Blunt liver trauma management has changed in the last two decades with the introduction of the computed tomography (CT) scan and non-operative management of stable patients.

OBJECTIVE

To determine the incidence, efficacy, and failure rate of blunt liver trauma non-operative management as well as the risk factors associated with such treatment in a level 1 trauma center in Colombia.

METHODS

We conducted an observational descriptive study on patients with blunt liver trauma who were admitted to a level 1 trauma center in Colombia. The evaluated outcomes were indications of immediate surgical treatment and the success of non-operative management.

RESULTS

A total of 73 patients were studied. The most common mechanism of trauma continues to be motor vehicle crashes. In 14 patients (19.2%), immediate surgical intervention was necessary and we observed a Revised Trauma Score (RTS) above 7.8 and intra-abdominal injuries as risk factors. Three patients died (21.4%). Fifty-nine patients (80.8%) received non-operative management, which failed in seven patients (11.2%). Age, severity of liver injury, and intra-abdominal injuries were not risk factors in the failure of non-operative management. Mortality in the non-operative management group was 1.7%.

CONCLUSION

Non-operative management is the treatment of choice for polytraumatized patients with blunt liver trauma who are hemodynamically stable. Non-operative management is an effective and safe treatment strategy. However, patients with an RTS score under 7.8 and other intra-abdominal non-liver injuries are at increased risk for an immediate surgical intervention.

Cr3+-doped fluorides and oxides: role of internal fields and limitations of the Tanabe-Sugano approach

This work is aimed at clarifying the changes on optical spectra of Cr(3+) impurities due to either a host lattice variation or a hydrostatic pressure, which can hardly be understood by means of the usual Tanabe-Sugano (TS) approach assuming that the Racah parameter, B, grows when covalency decreases. For achieving this goal, the optical properties of Cr(3+)-doped LiBaF(3) and KMgF(3) model systems have been explored by means of high level ab initio calculations on CrF(6)(3-) units subject to the electric field, E(R)(r), created by the rest of the lattice ions. These calculations, which reproduce available experimental data, indicate that the energy, E((2)E), of the (2)E(t(2g)(3)) → (4)A(2)(t(2g)(3)) emission transition is nearly independent of the host lattice. By contrast, the energy difference corresponding to (4)A(2)(t(2g)(3)) → (4)T(1)(t(2g)(2)e(g)(1)) and (4)A(2)(t(2g)(3)) → (4)T(2)(t(2g)(2)e(g)(1)) excitations, Δ((4)T(1); (4)T(2)), is shown to increase on passing from the normal to the inverted perovskite host lattice despite the increase in covalency, a fact which cannot be accounted for through the usual TS model. Similarly, when the Cr(3+)-F(-) distance, R, is reduced both Δ((4)T(1); (4)T(2)) and the covalency are found to increase. By analyzing the limitations of the usual model, we found surprising results that are shown to arise from the deformation of both 3d(Cr) and ligand orbitals in the antibonding e(g) orbital, which has a σ character and is more extended than the π t(2g) orbital. By contrast, because of the higher stiffness of the t(2g) orbital, the dependence of E((2)E) with R basically follows the corresponding variation of covalency in that level. Bearing in mind the similarities of the optical properties displayed by Cr(3+) impurities in oxides and fluorides, the present results can be useful for understanding experimental data on Cr(3+)-based gemstones where the local symmetry is lower than cubic.

3,5-diiodo-L-thyronine increases resting metabolic rate and reduces body weight without undesirable side effects

Recently, it was demonstrated that 3,5-diiodo-L-thyronine (T2) stimulates the resting metabolic rate (RMR), and reduces body-weight gain of rats receiving a high-fat diet. The aim of this study is to examine the effects of chronic T2 administration on basal metabolic rate and body weight in humans. Two euthyroid subjects volunteered to undergo T2 administration. Body weight, body mass index, blood pressure, heart rate, electrocardiogram, thyroid and liver ultrasonography, glycemia, total cholesterol, triglycerides, free T3 (FT3), free T4 (FT4), T2, thyroid stimulating hormone (TSH) and RMR were evaluated at baseline and at the end of treatment. RMR increased significantly in each subject. After continuing the T2 treatment for a further 3 weeks (at 300 mcg/day), body weight was reduced significantly (p<0.05) (about 4 percent), while the serum levels of FT3, FT4 and TSH, were unchanged. No side effects were observed at the cardiac level in either subject. No significant change was observed in the same subjects taking placebo.

Aptasensor based on the selective electrodeposition of protein-linked gold nanoparticles on screen-printed electrodes

The electrodeposition of DNA-gold nanoparticles previously developed in our group has been used as starting point for the electrodeposition of proteins attached to gold nanoparticles. We have performed a proof of principle by developing a methodology based on the electrodeposition of proteins bound to gold nanoparticles on screen-printed gold microelectrodes using, in a first approach, horseradish peroxide-conjugated gold nanoparticles (gold-HRP). The electrodeposition was achieved at a current positive potential of 800 mV vs. Ag/AgCl and the functionality of the electrodeposited HRP-particles was tested by electrochemical reduction of H(2)O(2). Furthermore, we used this proof of concept in an aptasensor application to detect Leishmania infantum KMP-11. Hence, we have demonstrated not only the functionality of the electrodeposition of proteins bound to gold nanoparticles, but also the utility of the method with the aim of developing a real biosensor containing multiple enzymes or proteins in a multimodular device.

Self-amplified spontaneous emission free-electron laser with an energy-chirped electron beam and undulator tapering

We report the first experimental implementation of a method based on simultaneous use of an energy chirp in the electron beam and a tapered undulator, for the generation of ultrashort pulses in a self-amplified spontaneous emission mode free-electron laser (SASE FEL). The experiment, performed at the SPARC FEL test facility, demonstrates the possibility of compensating the nominally detrimental effect of the chirp by a proper taper of the undulator gaps. An increase of more than 1 order of magnitude in the pulse energy is observed in comparison to the untapered case, accompanied by FEL spectra where the typical SASE spiking is suppressed.

Spectrochemical series and the dependence of Racah and 10 Dq parameters on the metal-ligand distance: microscopic origin

The origin of the spectrochemical series and the different dependence of crystal-field splitting (10Dq) and Racah parameters on the metal-ligand distance, R, is explored through ab initio calculations on Cr(3+)-doped K2NaScF6, Cs2NaYCl6, Cs2NaYBr6, and Cs2NaYI6 lattices. For this purpose both periodic and cluster calculations have been performed. An analysis of ab initio results proves that 10Dq values mostly come from the small admixture of deep nLs ligand orbitals present in the antibonding eg(∼ x(2)-y(2),3z(2)-r(2)) level and not from the dominant covalency with valence nLp ligand orbitals, which is actually responsible for the reduction of Racah parameters. This study thus reveals the microscopic origin of the stronger dependence upon R of 10Dq when compared to that observed for Racah parameters, thus explaining why electronic transitions which are 10Dq-independent give rise to sharp optical bands. As a salient feature, while the covalency with nLp levels increases significantly on passing from CrF6(3-) to CrI6(3-), the nLs admixture in eg is found to be practically unmodified. This fact helps to understand the progressive decrease of 10Dq through the series of CrF6(3-), CrCl6(3-), CrBr6(3-), and CrI6(3-) complexes embedded in the corresponding host lattices when compared at the corresponding equilibrium distance at zero pressure. The growing importance of the nLs admixture is well-depicted using deformation density diagrams on passing from the ground state (4)A2(t2g(3)) to the (4)T2(t2g(2)eg) excited state depicted at several R values.

Differential indirect activation of human invariant natural killer T cells by Toll-like receptor agonists

AIM

Invariant natural killer (iNK) T cells are activated by bacterial glycosphingolipids presented by CD1d on dendritic cells (DCs). Here, it was investigated whether Toll-like receptor (TLR) ligands derived from various microorganisms can either directly or indirectly (through DC activation) activate iNKT cells.

MATERIALS & METHODS

TLR expression by iNKT cells was examined and the ability of various TLR ligands to activate iNKT cells was evaluated.

RESULTS

Although human iNKT cells express all TLRs, apart from TLR8, they did not respond directly to TLR ligands. However, iNKT cells became strongly activated when total peripheral blood mononuclear cells were stimulated with TLR2/6, 7/8 and 9 ligands, but not or to a lesser extent with TLR3, 4 and 5 ligands. TLR-stimulated monocyte-derived DCs promoted iNKT cell phenotypic activation and, in turn, these activated iNKT cells further enhanced DC maturation.

CONCLUSION

TLR agonists may act as strong adjuvants for immunotherapy by promoting combined and reciprocal activation of iNKT cells and DCs.

Advances on aptamers targeting Plasmodium and trypanosomatids

Aptamers are single-stranded oligonucleotides (ssDNA or RNA) selected from combinatorial libraries by an in vitro process and possess a specific three-dimensional structure depending on its sequence. These molecules are able to recognize and, eventually, alter the activity of their targets by binding directly in a similar way to antibodies. Over the last years, aptamer technology has been used in a wide range of diagnostic and therapeutic applications and, concretely, several strategies are currently being explored using aptamers against Plasmodium and trypanosomatid proteins associated with parasitic diseases which affect hundreds of millions people. One approach tries to block the interaction between the parasite and the host using aptamers targeting host-cell matrix receptors. A second strategy consists in attack the parasite intracellularly targeting heme group or interfering in the intracellular RNA transport. In another strategy, aptamers targeting invariant polypeptides could be used as a specific drug delivery system into the parasite. Finally, aptamers addressed to re-direct the immune response of the infected host are being studied. Other potential use of the aptamers is as biorecognition element in diagnostic systems for parasitic diseases. In this paper, we briefly review how aptamers against Plasmodium and trypanosomatids are discovered, with a focus on recent advances that improve the aptamers properties as a real tool for parasite fighting.

Alterations of brain and cerebellar proteomes linked to Aβ and tau pathology in a female triple-transgenic murine model of Alzheimer's disease

The triple-transgenic Alzheimer (3 × Tg-AD) mouse expresses mutant PS1(M146V), APP(swe), and tau(P301L) transgenes and progressively develops plaques and neurofibrillary tangles with a temporal- and region-specific profile that resembles the neuropathological progression of Alzheimer's disease (AD). In this study, we used proteomic approaches such as two-dimensional gel electrophoresis and mass spectrometry to investigate the alterations in protein expression occurring in the brain and cerebellum of 3 × Tg-AD and presenilin-1 (PS1) knock-in mice (animals that do not develop Aβ- or tau-dependent pathology nor cognitive decline and were used as control). Finally, using the Ingenuity Pathway Analysis we evaluated novel networks and molecular pathways involved in this AD model. We identified several differentially expressed spots and analysis of 3 × Tg-AD brains showed a significant downregulation of synaptic proteins that are involved in neurotransmitter synthesis, storage and release, as well as a set of proteins that are associated with cytoskeleton assembly and energy metabolism. Interestingly, in the cerebellum, a structure not affected by AD, we found an upregulation of proteins involved in carbohydrate metabolism and protein catabolism. Our findings help to unravel the pathogenic brain mechanisms set in motion by mutant amyloid precursor protein (APP) and hyperphosphorylated tau. These data also reveal cerebellar pathways that may be important to counteract the pathogenic actions of Aβ and tau, and ultimately offer novel targets for therapeutic intervention.

Salmonella as live trojan horse for vaccine development and cancer gene therapy

The design of efficient vectors for vaccine development and cancer gene therapy is an area of intensive research. Bacteria-based vectors are being investigated as optimal vehicles for antigen and therapeutic gene delivery to immune and tumour cells. Attenuated Salmonella strains have shown great potential as live vectors with broad applications in human and veterinary medicine. An impressively high, and still growing, number of reports published over the last two decades have demonstrated the effectiveness in animal models of Salmonella-based therapies for the prevention and treatment of infectious and non-infectious diseases, as well as cancer. Further, the recent dramatic expansion in knowledge of genetics, biology and pathogenesis of the bacteria allows more rational design of Salmonella constructs tailored for specific applications. However, only few clinical trials have been conducted so far, and although they have conclusively demonstrated the safety of this system, the results on immunogenicity are less than optimal. Thus, more research particularly in target species is required to bring this system closer to human and veterinary use. In this review we first describe some particularities of the bacteria and its relationship with the host that could be on the basis of its success as vector, and then summarize the different strategies used so far to develop Salmonella-based vaccines for infectious diseases as well as for non-traditional indications such as prion and Alzheimer disease vaccination. Finally, we review the many different approaches that employ Salmonella for the design of new therapies for cancer.

FELASA recommendations for the education and training of laboratory animal technicians: Category A

The future laboratory animal technician in Europe will be provided with three different levels of education. All candidates have to start with an introductory course to reach level A0. At this level (A0) they will be able to assist in the laboratory animal facility by undertaking limited specific duties under supervision. Most A0 assistants will continue their education and training for at least one year while in full-time employment. This process will include continual assessment with the option of a final examination to become qualified at level A1. A1 represents a comprehensively educated laboratory animal technician with theoretical background knowledge and practical skills. Some of the A1 laboratory animal technicians may continue specific education for at least another year of full-time employment. They will develop knowledge and expertise as well as supervisory and basic managerial skills in order to obtain level A2.

Attenuation of invariant natural killer T-cell anergy induction through intradermal delivery of alpha-galactosylceramide

CD1d restricted, alpha-galactosylceramide (alphaGC) responsive invariant (i)NKT cells positively regulate immune responses. Both intravenous and intradermal administered alphaGC are known to activate iNKT cells. iNKT cells become unresponsive to a second intravenous alphaGC injection, whereas no data are available regarding potential anergy upon intradermal administration. Here, comparative analysis of two intradermal versus two intravenous injections in mice demonstrated that iNKT cell anergy was prevented by intradermal injection and when combined with a vaccine, superior tumor protection afforded by intradermally administered alphaGC. Moreover, human skin dendritic cells (DC) took up intradermally injected alphaGC and activated iNKT cells upon migration, while iNKT cells in human skin-draining lymph nodes expanded in response to alphaGC presented either by exogenously added DC or by CD1d positive antigen presenting cells in the lymph nodes. In conclusion, glycolipids such as alphaGC may greatly improve the efficacy of skin immunization strategies, targeting cutaneous and lymph node DC.

Cr3+ in layered perovskites: do the electron paramagnetic resonance parameters only depend on the impurity-ligand distances?

The actual value of axial, R(ax), and equatorial, R(eq), impurity-ligand distances for Cr(3+) embedded in tetragonal K(2)MgX(4) (X = F, Cl) lattices has been explored by means of density functional theory (DFT) calculations on clusters involving up to 69 ions using two different functionals. For K(2)MgF(4):Cr(3+) R(eq) and R(ax) are found to be coincident within only 0.5 pm. When the g tensor of K(2)MgF(4):Cr(3+) is derived considering only the CrF(6)(3-) unit in vacuo at the calculated equilibrium geometry the g(⊥)-g(||) quantity fails to reproduce the experimental value by one order of magnitude. In contrast, when the active electrons localized in the CrX(6)(3-) complex (X = F, Cl) are allowed to feel the anisotropic electric field coming from the rest of the lattice ions the splitting in the first excited state, (4)T(2), increases by one order of magnitude. The present results thus show that the g tensor anisotropy and the zero-field splitting constant, D, observed for K(2)MgX(4):Cr(3+) (X = F, Cl) are not mainly due to a local deformation of the CrX(6)(3-) octahedron but to the action of the internal electric field, often ignored when seeking the microscopic origin of electronic properties due to impurities in insulating lattices. Accordingly, serious doubts on the validity of the superposition model are cast by the present work.

Chronic 17beta-estradiol treatment improves skeletal muscle insulin signaling pathway components in insulin resistance associated with aging

Insulin resistance is a common feature of aging in both humans and rats. In the case of females, it seems to be related to loss of gonadal function, due mainly due to a decrease in plasma estrogen levels. Several causes have been postulated for this insulin resistance, among them changes in several steps of the insulin pathway. In view of these findings, the purpose of the present study was to examine the role of chronic 17beta-estradiol treatment on insulin sensitivity during the aging process, and its effects on levels of the insulin-sensitive glucose transporter Glut4 (both total and plasma membrane localized), the interaction between p85alpha subunit of PI3-k and IRS-1, Tyr- and Ser-612 phosphorylation of IRS-1 levels, and Ser-473 phosphorylation of Akt. The present findings indicate that 17beta-estradiol treatment is able to minimize the deleterious effect of aging on insulin sensitivity, at least at the level of plasma membrane localized Glut4. Nevertheless further research is needed to determine this conclusively.

Tunneling splitting of Jahn-Teller ions in oxides

The magnitude of tunneling splitting, 3Gamma, that governs decoherence in quantum systems under symmetric potentials, is frequently unknown. Using first-principles calculations, we have obtained 3Gamma for a number of E[symbol:see text]e Jahn-Teller impurities in solids. Calculated values span 6 orders of magnitude on passing from KCl:Ag{2+} to MgO:Cu{2+}. Values associated with Cu2+- and Ag2+-doped MgO are 2 orders of magnitude larger than those previously assumed and consistent with the existence of a dynamic Jahn-Teller effect. The origin and enhancement with pressure of these high 3Gamma values is discussed in detail.

313 ASSESSMENT OF SPERM DNA FRAGMENTATION IN CANINE EJACULATES USING THE Sperm-Halomax® KIT: PRELIMINARY RESULTS

Recently, a new procedure for the analysis of sperm DNA fragmentation has been developed for humans and different mammalian species, using a commercial kit based on the sperm chromatin dispersion (SCD) test; however, a descriptive study in canine semen has not been performed. The aim of this work was to assess the sperm DNA fragmentation in canine ejaculates using the SCD test and 2 different staining techniques. For this purpose, ejaculates were collectedby digital manipulation from4 healthy dogs of different breeds (1 German Pointer, 2 Spanish Greyhounds, and 1 Crossbreed). After collection, the sperm-rich fraction of the ejaculates from 3 dogs were pooled each time (n = 4) and then extended in Dulbecco’s phosphate buffered saline. All the pooled semen samples presented physiological values concerning routine semen parameters (motility, morphology, and sperm concentration). The sperm DNA fragmentation was assessed using the Sperm-Halomax® commercial kit specifically developed for canine semen (Halotech DNA SL, Madrid, Spain). Two semen aliquots of the diluted pooled semen samples were processed on each pre-treated slide provided in the kit following the manufacturer’s instructions. The last step was the staining technique. We stained each slide with 2 different staining procedures. The first half of the slide was stained with propidium iodide (Sigma-Aldrich, St. Louis, MO, USA) mixed in a proportion 1 : 1 with an antifading solution. The second half of the slide was stained for 15 min in Wright solution (1.01383.0500, Merck, Whitehouse Station, NJ, USA) 1 :1 in Phosphate Buffer pH 6.88 (1.07294.1000, Merck). The stained slides were observed using fluorescence and light microscopy, respectively. Five hundred sperm per slide were counted. Spermatozoa with fragmented DNA showed a large and spotty halo of chromatin dispersion. Unfragmented sperm only showed a small and compact halo. Statistical analyses were performed using the Statistical Package for Social Science version 12.0 (SPSS Inc., Chicago, IL, USA). The sperm DNA fragmentation index was compared between Wright and fluorescence staining methods by ANOVA. Results were expressed as mean ± standard error of the mean. The first report of the sperm DNA fragmentation index in canine ejaculates was 2.26 ± 0.53% for Wright staining and 1.99 ± 0.10% for fluorescence technique. No differences were found between staining procedures. In conclusion, it was possible to assess the sperm DNA fragmentation of canine ejaculates using 2 different staining procedures, expecting that continuous research could be useful in defining the role of DNA fragmentation SCD test in canine semen evaluation and cryopreservation.

90 EFFECT OF EGG YOLK ON THE KINEMATICS AND ACROSOME MEMBRANE INTEGRITY OF COOLED-REWARMED CANINE SPERMATOZOA

Tris-egg yolk-based diluents provide adequate cryoprotection for the sperm of most species. This study was conducted to compare the ability of Tris-glucose extender containing 2 different concentrations of egg yolk to maintain sperm motility and acrosome integrity of canine spermatozoa during 72 h of preservation. For this purpose, a total of 20 ejaculates from 4 clinically healthy dogs (2 Spanish Greyhound, 1 German Pointer, and 1 Crossbreed) were collected by digital manipulation. The sperm-rich fraction of each ejaculate was divided into 2 aliquots. Then, they were diluted in Tris-based extender and centrifuged at 700g for 8 min. Sperm pellets were resuspended in either Tris buffer added to 20% (EY20) or 10% centrifuged egg yolk (EY10) and cooled to 5°C over 72 h. The effects of these extenders on motility and acrosome integrity were assessed objectively using a computer-aided semen analyzer (Sperm Class Analyzer, Microptic SL, Spain) and Spermac® staining, respectively. Each cooled-rewarmed semen sample was evaluated after 24, 48, and 72 h of preservation. Sperm motion parameters shown by computer-assisted semen analysis (CASA) are progressively motile (PMS) and motile spermatozoa (MS), curvilinear velocity (CLV), average path velocity (APV), progressive speed (SLV), and lateral head displacement (LHD). Data were statistically analysed by ANOVA. Dependent variables expressed as percentages were arsine-transformed before analysis. Differences between mean values were evaluated by the Duncan method. Data were presented as mean ± SEM. Differences were considered significant when P < 0.05. Analyses were performed using the statistical package SPSS 12.0. A total of 98 172 motile sperm trajectories were analyzed by CASA: 52 259 in EY20 and 45 913 in EY10. After 24, 48, and 72 h of preservation, MS and PMS were statistically higher (P < 0.01) in EY20. No significant differences were found for LHD using either extender over a 72-h period. No significant differences were observed for CLV using either extender during the first 2 days. At Day 3, CLV data were significantly higher (P < 0.01) in EY20. Similarly, from Day 2, APV was significantly higher (P < 0.001) in EY20. After 24 h of preservation, SLV was statistically higher (P < 0.001) in EY10, whereas the opposite tendency was found at Day 3. No significant differences were observed for SLV using either extender after 48 h of preservation. During the first 2 days, acrosome integrity was statistically higher (P < 0.001) in EY20. At hour 72, higher acrosome integrity (P < 0.001) was observed in EY10. In conclusion, we have observed that the EY20 extender provided higher motility after 72 h of chilled preservation; however, the acrosome membrane integrity was better preserved in EY10.

Selective immobilization of oligonucleotide-modified gold nanoparticles by electrodeposition on screen-printed electrodes

Here, we describe a proof of concept procedure for the selective immobilization of oligonucleotides functionalized gold nanoparticle probes (affinity modules) on arrayed screen-printed gold electrodes. Current microarrays are using many different ways to address their DNA probes onto the transducer area. For that reason, we have mixed the electrodeposition of metals, which is a very well known process, in addition with the DNA-gold nanoparticles formation, which is an area of great interest in biosensing applications in the field of genomics, clinical and warfare applications. Combining these fields, we have developed a novel method for the immobilization of gold nanoparticles conjugated with oligonucleotides (affinity modules) onto screenprinting gold electrodes through electrodeposition at a current positive potential of 800mV vs. Ag/AgCl. The modules were selectively immobilized onto the electrode surface being, afterwards, ready for a successful hybridization. The gold colloids take the advantage of being a carrier that allows the immobilization of any kind of bioreceptor in the same conditions and the capability of quality control analysis before the electrodeposition procedure. With this system, we avoided non-specific interactions between the transduction layer and the bioreceptor and in the case of DNA oligonucleotides allowed us the immobilization of multiple sequences in a multimodular device for a further industrial process of cheaper biochip fabrication.

[Stereotactic radiation therapy]

Stereotactic radiotherapy is a form of external radiotherapy that employs a system of three dimensional coordinates independent of the patient for the precise localisation of the lesion. It also has the characteristic that the radiation beams are conformed and precise, and converge on the lesion, making it possible to administer very high doses of radiotherapy without increasing the radiation to healthy adjacent organs or structures. When the procedure is carried out in one treatment session it is termed radiosurgery, and when administered over several sessions it is termed stereotactic radiotherapy. Special systems of fixing or immobilising the patient (guides or stereotactic frames) are required together with radiotherapy devices capable of generating conformed beams (lineal accelerator, gammaknife, cyberknife, tomotherapy, cyclotrons). Modern stereotactic radiotherapy employs intra-tumoural radio-opaque frames or CAT image systems included in the irradiation device, which make possible a precise localisation of mobile lesions in each treatment session. Besides, technological advances make it possible to coordinate the lesion's movements in breathing with the radiotherapy unit (gating and tracking) for maximum tightening of margins and excluding a greater volume of healthy tissue. Radiosurgery is mainly indicated in benign or malign cerebral lesions less than 3-4 centimetres (arteriovenous malformations, neurinomas, meningiomas, cerebral metastases) and stereotactic radiotherapy is basically administered in tumours of extracraneal localisation that require high conforming and precision, such as inoperable early lung cancer and hepatic metastasis.

17beta-estradiol treatment is unable to reproduce p85 alpha redistribution associated with gestational insulin resistance in rats

Maternal metabolic adaptations are essential to ensure proper fetal development. According to changes in insulin sensitivity, pregnancy can be divided into two periods: early pregnancy, characterized by an increase in maternal insulin sensitivity, and late pregnancy, in which there is a significant increase in insulin resistance. The aims of the present work were two-fold: firstly, the molecular mechanisms associated with the development of pregnancy-related insulin resistance in peripheral tissues, mainly retroperitoneal adipose tissue and skeletal muscle, were studied in pregnant rats at 6, 11, and 16 days gestation. Secondly, the role of 17beta-estradiol in this process was elucidated in an animal model consisting of ovariectomized rats treated with 17beta-estradiol to mimic plasma gestational levels. The results support the conclusion that retroperitoneal adipose tissue plays a pivotal role in the decrease in insulin sensitivity during pregnancy, through a mechanism that involves p85 alpha redistribution to the insulin receptor and impairment of Glut4 translocation to the plasma membrane. Treatment with 17beta-estradiol did not reproduce the molecular adaptations that occur during pregnancy, suggesting that other hormonal factors presents in gestation but absent in our experimental model are responsible for p85 alpha redistribution to the insulin receptor.

Nematode response to metal, PAHs and organic enrichment in tourist marinas of the Mediterranean Sea

The structure of nematode assemblages was investigated in the sediments of two different tourist marinas in the Mediterranean Sea and related to pollution variables. Nematode densities and generic compositions were determined, as were concentrations of heavy metals, PAHs and organic matter. Results showed different assemblages at the two marinas, with a dominance of the genera Paralongicyatholaimus and Daptonema. Significant correlations between nematodes and concentrations of environmental contaminants were found. In particular, Paralongicyatholaimus showed a significant negative correlation with Cu concentrations and was almost absent at the stations where higher Cu concentrations were found. The presence of sensitive/tolerant nematode genera represents a promising tool to identify areas subjected to a higher level of disturbance and to define the correct environmental management strategy for harbors.

Portoumbilical anastomosis as a simple method of transient portosystemic shunt during liver transplantation

BACKGROUND

This article describes a new method of transient intraoperative portosystemic shunting, Splachnic edema after portal cross-clamping can be a dangerous complication during the anhepatic phase of the liver transplant operation. The current method seeks to avoid this problem, without the use of external venovenous bypass pump, by a temporary portocaval shunt, with retrohepatic cava preservation as first described experimentally in dogs by Fonkalsrud et al in 1966.

METHODS AND RESULTS

Among 227 liver transplant operations, we utilized a transient portosystemic shunt in 29 cases. The indication to perform a temporary shunt in all cases was the development of splachnic edema. In 3 instances, we performed a portoumbilical anastomosis using a prominent umbilical vein. The other 26 procedures employed the usual portocaval shunts. In these cases, splachnic congestion and onset of edema developed after cross-clamping of the round ligament and the portal vein, which resolved after the portoumbilical anastomosis.

DISCUSSION

The flow in the shunt was in all cases greater than 1 L/min. The most important risk factor for the development of splachnic edema was the presence of a patent umbilical vein, which occurred in 34.5% of shunted patients.

CONCLUSION

The use of a patent umbilical vein to perform a portoumbilical shunt was an effective, easy method to decompress the splachnic area, avoiding dangerous congestion and edema.

Noonan syndrome associated with systemic lupus erythematosus

Noonan syndrome (NS) is a developmental disorder characterised mainly by cardiac defects and craniofacial dysmorphia. An association between NS and some autoimmune diseases, such as thyroiditis and systemic lupus erythematosus (SLE), has been suggested. We report the case of a 28-year-old man with a diagnosis of NS and autoimmune hypothyroidism who developed symptoms and immunologic features of SLE.

Defining the transcriptomic and proteomic profiles of rat ageing skeletal muscle by the use of a cDNA array, 2D- and Blue native-PAGE approach

We defined the transcriptomic and proteomic profiles of rat ageing skeletal muscle using a combined cDNA array, 2D- and Blue native-PAGE approach. This was allowed to obtain an overview of the interrelated events leading to the transcriptome/proteome/mitoproteome changes likely to underlie the structural/metabolic features of aged skeletal muscle. The main differences were found in genes/proteins related to energy metabolism, mitochondrial pathways, myofibrillar filaments, and detoxification. Concerning the abundance of mitochondrial OXPHOS complexes as well as their supramolecular organization and activity, mitochondria from old rats, when compared with those from young rats, contained significantly lower amounts of complex I (NADH:ubiquinone oxidoreductase), V (FoF1-ATP synthase), and III (ubiquinol:cytochrome c oxidoreductase). The same mitochondria contained a significantly larger amount of complex II (succinate:ubiquinone oxidoreductase), but an unchanged amount of complex IV (cytochrome c oxidase, COX). When comparing the supercomplex profiles between young and old muscle mitochondria, the densitometric analysis revealed that lighter supercomplexes were significantly reduced in older mitochondria, and that in the older group the major supercomplex bands were those representing heavier supercomplexes, likely suggesting a compensatory mechanism that, in ageing muscle, is functionally directed towards substrate channeling and catalytic enhancement advantaging the respirosome.

3,5-Diiodo-L-thyronine rapidly enhances mitochondrial fatty acid oxidation rate and thermogenesis in rat skeletal muscle: AMP-activated protein kinase involvement

Triiodothyronine regulates energy metabolism and thermogenesis. Among triiodothyronine derivatives, 3,5-diiodo-l-thyronine (T(2)) has been shown to exert marked effects on energy metabolism by acting mainly at the mitochondrial level. Here we investigated the capacity of T(2) to affect both skeletal muscle mitochondrial substrate oxidation and thermogenesis within 1 h after its injection into hypothyroid rats. Administration of T(2) induced an increase in mitochondrial oxidation when palmitoyl-CoA (+104%), palmitoylcarnitine (+80%), or succinate (+30%) was used as substrate, but it had no effect when pyruvate was used. T(2) was able to 1) activate the AMPK-ACC-malonyl-CoA metabolic signaling pathway known to direct lipid partitioning toward oxidation and 2) increase the importing of fatty acids into the mitochondrion. These results suggest that T(2) stimulates mitochondrial fatty acid oxidation by activating several metabolic pathways, such as the fatty acid import/beta-oxidation cycle/FADH(2)-linked respiratory pathways, where fatty acids are imported. T(2) also enhanced skeletal muscle mitochondrial thermogenesis by activating pathways involved in the dissipation of the proton-motive force not associated with ATP synthesis ("proton leak"), the effect being dependent on the presence of free fatty acids inside mitochondria. We conclude that skeletal muscle is a target for T(2), and we propose that, by activating processes able to enhance mitochondrial fatty acid oxidation and thermogenesis, T(2) could play a role in protecting skeletal muscle against excessive intramyocellular lipid storage, possibly allowing it to avoid functional disorders.