Multisession anodal epidural direct current stimulation of the auditory cortex delays the progression of presbycusis in the Wistar rat

Presbycusis or age-related hearing loss (ARHL) is one of the most prevalent chronic health problems facing aging populations. Along the auditory pathway, the stations involved in transmission and processing, function as a system of interconnected feedback loops. Regulating hierarchically auditory processing, auditory cortex (AC) neuromodulation can, accordingly, activate both peripheral and central plasticity after hearing loss. However, previous ARHL-prevention interventions have mainly focused on preserving the structural and functional integrity of the inner ear, overlooking the central auditory system. In this study, using an animal model of spontaneous ARHL, we aim at assessing the effects of multisession epidural direct current stimulation of the AC through stereotaxic implantation of a 1-mm silver ball anode in Wistar rats. Consisting of 7 sessions (0.1 mA/10 min), on alternate days, in awake animals, our stimulation protocol was applied at the onset of hearing loss (threshold shift detection at 16 months). Click- and pure-tone auditory brainstem responses (ABRs) were analyzed in two animal groups, namely electrically stimulated (ES) and non-stimulated (NES) sham controls, comparing recordings at 18 months of age. At 18 months, NES animals showed significantly increased threshold shifts, decreased wave amplitudes, and increased wave latencies after click and tonal ABRs, reflecting a significant, spontaneous ARHL evolution. Conversely, in ES animals, no significant differences were detected in any of these parameters when comparing 16 and 18 months ABRs, indicating a delay in ARHL progression. Electrode placement in the auditory cortex was accurate, and the stimulation did not cause significant damage, as shown by the limited presence of superficial reactive microglial cells after IBA1 immunostaining. In conclusion, multisession DC stimulation of the AC has a protective effect on auditory function, delaying the progression of presbycusis.

Mature iPSC-derived astrocytes of an ALS/FTD patient carrying the TDP43A90V mutation display a mild reactive state and release polyP toxic to motoneurons

Astrocytes play a critical role in the maintenance of a healthy central nervous system and astrocyte dysfunction has been implicated in various neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). There is compelling evidence that mouse and human ALS and ALS/FTD astrocytes can reduce the number of healthy wild-type motoneurons (MNs) in co-cultures or after treatment with astrocyte conditioned media (ACM), independently of their genotype. A growing number of studies have shown that soluble toxic factor(s) in the ACM cause non-cell autonomous MN death, including our recent identification of inorganic polyphosphate (polyP) that is excessively released from mouse primary astrocytes (SOD1, TARDBP, and C9ORF72) and human induced pluripotent stem cells (iPSC)-derived astrocytes (TARDBP) to kill MNs. However, others have reported that astrocytes carrying mutant TDP43 do not produce detectable MN toxicity. This controversy is likely to arise from the findings that human iPSC-derived astrocytes exhibit a rather immature and/or reactive phenotype in a number of studies. Here, we have succeeded in generating a highly homogenous population of functional quiescent mature astrocytes from control subject iPSCs. Using identical conditions, we also generated mature astrocytes from an ALS/FTD patient carrying the TDP43A90V mutation. These mutant TDP43 patient-derived astrocytes exhibit key pathological hallmarks, including enhanced cytoplasmic TDP-43 and polyP levels. Additionally, mutant TDP43 astrocytes displayed a mild reactive signature and an aberrant function as they were unable to promote synaptogenesis of hippocampal neurons. The polyP-dependent neurotoxic nature of the TDP43A90V mutation was further confirmed as neutralization of polyP in ACM derived from mutant TDP43 astrocytes prevented MN death. Our results establish that human astrocytes carrying the TDP43A90V mutation exhibit a cell-autonomous pathological signature, hence providing an experimental model to decipher the molecular mechanisms underlying the generation of the neurotoxic phenotype.

Post-viral idiopathic purpura fulminans is associated with inherited thrombophilia and anti-cardiolipin antibodies

Introduction

Idiopathic purpura fulminans (IPF) is a rare and severe coagulation disorder, associated with transient anti-protein S (anti-PS) antibodies in the context of post-viral infection such as varicella. Anti-protein S antibodies are frequently found in the context of varicella, in contrast with the rarity of IPF. Other factors such as anti-phospholipid antibodies (APL) and inherited thrombophilia may be associated with severe vascular complication.

Method

This is an ancillary study of a French multicenter retrospective series and systematic review of literature. We analyzed patients who were tested for inherited thrombophilia, namely antithrombin, protein C, protein S deficiency; prothrombin gene G20210A polymorphism (FII:G20210A),Factor V R506Q polymorphism (FV:R506Q); and/or for APL (lupus anticoagulant (LA), anti-cardiolipin antibodies (ACL), or anti-beta 2-GPI antibodies (Aβ2GP1).

Results

Among the 25 patients tested for inherited thrombophilia, 7 (28%) had positive results. Three had FV R506Q, two FII:G20210A, one compound heterozygote FV:R506Q associated to FII:G20210A, and one protein C deficiency. APL testing was performed in 32 patients. It was positive in 19 patients (59%): 17 ACL (53%), 5 LA (16%), 4 Aβ2GP1 (13%). The risk of severe complications was not associated with presence of inherited thrombophilia or APL presence, with RR: 0.8 [95% CI: 0.37-1.71], p = 1 and RR: 0.7 [95% CI: 0.33-1.51], p = 0.39, respectively. We found a high prevalence of inherited thrombophilia or APL in a population of patients with IPF. However, we do not find an association with the occurrence of severe vascular complications or venous thromboembolism.

Umbilical cord mesenchymal stromal cells transplantation delays the onset of hyperglycemia in the RIP-B7.1 mouse model of experimental autoimmune diabetes through multiple immunosuppressive and anti-inflammatory responses

Type 1 diabetes mellitus (T1DM) is an autoimmune disorder specifically targeting pancreatic islet beta cells. Despite many efforts focused on identifying new therapies able to counteract this autoimmune attack and/or stimulate beta cells regeneration, TD1M remains without effective clinical treatments providing no clear advantages over the conventional treatment with insulin. We previously postulated that both the inflammatory and immune responses and beta cell survival/regeneration must be simultaneously targeted to blunt the progression of disease. Umbilical cord-derived mesenchymal stromal cells (UC-MSC) exhibit anti-inflammatory, trophic, immunomodulatory and regenerative properties and have shown some beneficial yet controversial effects in clinical trials for T1DM. In order to clarify conflicting results, we herein dissected the cellular and molecular events derived from UC-MSC intraperitoneal administration (i.p.) in the RIP-B7.1 mouse model of experimental autoimmune diabetes. Intraperitoneal (i.p.) transplantation of heterologous mouse UC-MSC delayed the onset of diabetes in RIP-B7.1 mice. Importantly, UC-MSC i. p. transplantation led to a strong peritoneal recruitment of myeloid-derived suppressor cells (MDSC) followed by multiple T-, B- and myeloid cells immunosuppressive responses in peritoneal fluid cells, spleen, pancreatic lymph nodes and the pancreas, which displayed significantly reduced insulitis and pancreatic infiltration of T and B Cells and pro-inflammatory macrophages. Altogether, these results suggest that UC-MSC i. p. transplantation can block or delay the development of hyperglycemia through suppression of inflammation and the immune attack.

Health protection among own account and platform workers during COVID19 in Chile. The PWR project

Background

In the last decades, non-standard employment has grown globally. Especially for own account workers (OAW), this implies the self-management of economic, health and other work-related risks. In the context of COVID19, this management was stressed by lockdowns and the novel health risks imposed by an unknown and highly contagious virus, demanding the incorporation of new knowledge and preventive actions. As part of a six-country multiple case qualitative study on non-standard workers (NSW), we explore their experiences and strategies deployed to protect their health while continuing to work.

Methods

We performed 40 in-depth interviews to NSWs between October 2020 and February 2021, identified through the PWR online-survey and selected through an intentional sampling strategy according to levels of precarity (high-low), gender (male/female) and age (18-39/40-55). Interviews were analysed through abductive thematic analysis.

Results

We observed a significant transfer to platform, Uber-like jobs in the delivery of goods during lockdown (n = 7). In the absence of institutional prevention programs and provision of protective equipment, OAWs (n = 13) refer the self-provision of COVID19 prevention to protect themselves and their families while continuing to work, deploying a series of strategies amidst limited understanding of both mode of transmission of the virus and actual effective preventive measures. This had serious consequences for them and their families, expressed in anguish, sense of lack of control, fear, and fragility in the face of a major health risk given their constant potential exposure to the virus, leading to both physical and mental health problems, as well as COVID19 infection.

Conclusions

The substantial growth worldwide of gig delivery work during lockdowns magnified a pressing public health problem, critically requiring social security for gig and OAWs and the development of more equitable and accessible occupational health for all.

Key messages

• Substantial growth worldwide of gig delivery work during lockdowns magnified a pressing public health problem.

• Social security for gig and OAWs are critically required as well as the development of more equitable and accessible occupational health for all.

BET bromodomain inhibitors PFI-1 and JQ1 are identified in an epigenetic compound screen to enhance C9ORF72 gene expression and shown to ameliorate C9ORF72-associated pathological and behavioral abnormalities in a C9ALS/FTD model

BACKGROUND

An intronic GGGGCC (G4C2) hexanucleotide repeat expansion (HRE) in the C9ORF72 gene is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), referred to as C9ALS/FTD. No cure or effective treatment exist for C9ALS/FTD. Three major molecular mechanisms have emerged to explain C9ALS/FTD disease mechanisms: (1) C9ORF72 loss-of-function through haploinsufficiency, (2) dipeptide repeat (DPR) proteins mediated toxicity by the translation of the repeat RNAs, and more controversial, (3) RNA-mediated toxicity by bidirectional transcription of the repeats that form intranuclear RNA foci. Recent studies indicate a double-hit pathogenic mechanism in C9ALS/FTD, where reduced C9ORF72 protein levels lead to impaired clearance of toxic DPRs. Here we explored whether pharmacological compounds can revert these pathological hallmarks in vitro and cognitive impairment in a C9ALS/FTD mouse model (C9BAC). We specifically focused our study on small molecule inhibitors targeting chromatin-regulating proteins (epidrugs) with the goal of increasing C9ORF72 gene expression and reduce toxic DPRs.

RESULTS

We generated luciferase reporter cell lines containing 10 (control) or ≥ 90 (mutant) G4C2 HRE located between exon 1a and 1b of the human C9ORF72 gene. In a screen of 14 different epidrugs targeting bromodomains, chromodomains and histone-modifying enzymes, we found that several bromodomain and extra-terminal domain (BET) inhibitors (BETi), including PFI-1 and JQ1, increased luciferase reporter activity. Using primary cortical cultures from C9BAC mice, we further found that PFI-1 treatment increased the expression of V1-V3 transcripts of the human mutant C9ORF72 gene, reduced poly(GP)-DPR inclusions but enhanced intranuclear RNA foci. We also tested whether JQ1, an BETi previously shown to reach the mouse brain by intraperitoneal (i.p.) injection, can revert behavioral abnormalities in C9BAC mice. Interestingly, it was found that JQ1 administration (daily i.p. administration for 7 days) rescued hippocampal-dependent cognitive deficits in C9BAC mice.

CONCLUSIONS

Our findings place BET bromodomain inhibitors as a potential therapy for C9ALS/FTD by ameliorating C9ORF72-associated pathological and behavioral abnormalities. Our finding that PFI-1 increases accumulation of intranuclear RNA foci is in agreement with recent data in flies suggesting that nuclear RNA foci can be neuroprotective by sequestering repeat transcripts that result in toxic DPRs.

P185 Primary cardiac lymphoma: an unexpected finding

BACKGROUND

Primary cardiac malignancies are rare, with a reported incidence of 0.1%. Up to 10% of cardiac tumors are malignant and primary cardiac lymphoma represents (PCL) a very low proportion of them. The wide variety of clinical manifestations and the inespecificity of them, difficults the diagnosis and delays treatment impacting directly in the prognosis of these patients. Here we present a lady with diagnosis of PCL treated in our center.

CASE REPORT

We present a 69 year old female with arterial hypertension and paroxismal atrial fibrilation that attended our clinic in april 2013. She referred severe dyspnoea with daily activities and peripheral oedema for the last three weeks. She also complaint of painful swallowing for bothliquids and solids. Physical exploration was unremarkable and observations where within normal limits. Transthoracic echocardiogram (TTE) was performed which showed an hipoechogenic mass invading the right ventricle, both atria and left ventricle outflow tract. She underwent cardiac MRI which revealed a myocardial isointense mass, with marked signal enhancement in T2 and heterogeneity in late gadolinium enhancement sequences, that was consistent with primary cardiac lymphoma. For histologycal characterization, biopsy of the mass guided with endoscopic ultrasonography was performed, confirming B-cell lymphoma. Positron emmision tomography (PET) scan showed bulky hypercaptant mass invading both atria, superior vena cava and pericardium, with hypercaptant adenopathies in right pulmonary hilum, subcarinal and phrenic chain. Her case was discussed in multidisciplinary team meeting and prompt initiation of treatment under R-CHOP regime was decided. After three cycles, follow up PET was requested, and revealed complete metabolic response. A repeat TTE showed only minimal infiltration of the right atria without ventricular involvement or hemodynamic compromise.

DISCUSSION

The patient we presented, was sent to Cardiology due to heart failure symptoms. Acute heart failure as well as embolisation and life-threatening arrythmias are typical manifestations of PCL. As reported in the literature, our case was a diffuse large B-cell lymphoma, which is the most frequent subtype. Dysphagia, exertional dyspnoea and constitutional symptoms can be present in early stages, as our patient referred. The main strength of this case is based on the quick diagnosis and early treatment. In contrary to what is reported, the overall survival was excellent, and to date the patient is still alive with no signs of relapse. Although TTE sensitivity is 55-60%, it has a key role in the diagnosis, which was supported later on MRI. Right chambers (specially right atria) are more typically involved than the left heart, including right venous drainage. Early systemic chemotherapy can achieve a high response rate and improve survival.

Abstract P185 Figure. Img1

P677 When to look for wtTTR amyloidosis in heart failure: increasing chances of positive gammagraphic study

Introduction

Wild type transtirretin (wtATTR) amyloidosis has become increasingly recognized as a major cause for heart failure (HF). Diagnosis requires complex work up such as DPD scintigraphy (DPDs). Availability of DPDs is limited urging to identify factors to increase its diagnostic rentability.

Methods

Retrospective study of HF patients between 2013 and 2019 with suspected wtATTR and DPDs was performed. Baseline characteristics, biomarkers, EKG findings, TTE parameters (LVEF, LV diastolic function, TAPSE, interventricular septum (IVS), LV mass (LVM), relative LV wall thickness (RWT), indexed LVTD volume and diameter, indexed LA diameter (iAPLAD)) and DPDs results were studied. Two groups were created according to DPDs (SP those with positive results for amyloidosis and SN those with negative results). For statistical SPSS v.21 was used.

Results

37 patients were studied. In our population 54% had positive DPDs for amyloidosis. Among SP patients 50% were classified as grade 2 of Perugini classification meanwhile 50% were grade 3; mean value of heart to contralateral ratio was 2,73 ± 0,8. There were no differences in NYHA classification. Differences among SP and SN patients are reflected in Table 1.

Conclusions

In our population SP was found to have higher biomarkers values and higher IVS, LVM, RWT and iAPLAD with poorer RV function. Further investigation is needed in order to confirm our result and identify prognostic factors.

Table 1: Results Total (37) PS (20) PN (17) p value Age (Y) 78 ± 7,9 80 ± 6,5 75,29 ± 8,7 0,05 Gender (male) (%) 30 (8) 19 (95) 11(64) 0,11 Carpal tunnel sdr (%) 3(8) 3 (15) 0 (0) 0,09 Systolic blood pressure (x ± sd) 127 ± 21 118 ± 18 138,5 ± 19 <0,01 ProBNP (x ± sd) 3596 ± 4002 4615 ± 4538 1761 ± 1927 <0,05 Troponin T (x ± sd) 132 ± 360 66,4 ± 35 43 ± 39 0,09 Pseudoinfarction pattern (%) 26 (70) 17 (85) 9 (52) <0,05 IVS (mm) (x ± sd) 14,6 ± 4,5 16,6 ± 5,3 13 ± 3 <0,01 LVM (g/m2) (x ± sd) 142,5 ± 68 180 ± 80 111 ± 32 <0,01 RWT (x ± sd) 0,68 ± 0,42 0,8 ± 0,24 0,56 ± 0,5 <0,01 LVEF (%) (x ± sd) 57,4 ± 11 54 ± 12 60 ± 10 0,12 iAPLAD (mm/m2) (x ± sd) 25,4 ± 6 28,7 ± 6 22,7 ± 4,3 <0,01 TAPSE (mm) (x ± sd) 18,6 ± 5 16,1 ± 4 20,6 ± 5 <0,05 IVS = interventricular septum; LVM = left ventricular mass; RWT = relative wall thickness; iAPLAD= indexed anteroposterior left atrium diameter.

Associations between cerebrovascular risk factors and parkinson disease

OBJECTIVE

To determine whether cerebrovascular risk factors are associated with subsequent diagnoses of Parkinson disease, and whether these associations are similar in magnitude to those with subsequent diagnoses of Alzheimer disease.

METHODS

This was a retrospective cohort study using claims data from a 5% random sample of Medicare beneficiaries from 2008 to 2015. The exposures were stroke, atrial fibrillation, coronary disease, hyperlipidemia, hypertension, sleep apnea, diabetes mellitus, heart failure, peripheral vascular disease, chronic kidney disease, chronic obstructive pulmonary disease, valvular heart disease, tobacco use, and alcohol abuse. The primary outcome was a new diagnosis of idiopathic Parkinson disease. The secondary outcome was a new diagnosis of Alzheimer disease. Marginal structural Cox models adjusting for time-dependent confounding were used to characterize the association between exposures and outcomes. We also evaluated the association between cerebrovascular risk factors and subsequent renal colic (negative control).

RESULTS

Among 1,035,536 Medicare beneficiaries followed for a mean of 5.2 years, 15,531 (1.5%) participants were diagnosed with Parkinson disease and 81,974 (7.9%) were diagnosed with Alzheimer disease. Most evaluated cerebrovascular risk factors, including prior stroke (hazard ratio = 1.55; 95% confidence interval = 1.39-1.72), were associated with the subsequent diagnosis of Parkinson disease. The magnitudes of these associations were similar, but attenuated, to the associations between cerebrovascular risk factors and Alzheimer disease. Confirming the validity of our analytical model, most cerebrovascular risk factors were not associated with the subsequent diagnosis of renal colic.

INTERPRETATION

Cerebrovascular risk factors are associated with Parkinson disease, an effect comparable to their association with Alzheimer disease. ANN NEUROL 2019;86:572-581.

Osteoblasts MC3T3-E1 Response in 2D and 3D Cell Cultures Models to High Carbon Content CoCr Alloy Particles. Effect of Metallic Particles on Vimentin Expression

The study of the biocompability of the metallic materials is a priority treating to avoid the osteolysis and aseptic loosening of prosthesis. Wear debris is considered one of the main factors responsible for aseptic loosening of orthopedic endoprostheses. We examined the response of mouse osteoblasts MC3T3-E1 to high carbon cobalt-chrome (HCCoCr) particles obtained a) from wear-corrosion assays on a pin-on-disk tribometer using as pair an alumina ball and a disc of a HCCoCr alloy, and b) HCCoCr bulk particles obtained by nitrogen gas atomization from an alloy used in clinic for prostheses application. Mitochondrial activity and lactate dehydrogenase activity assayed in 2D and 3D osteoblasts cell culture models were used to evaluate the cellular response to size, shape, and chemical composition of the metallic particles. 2D cell model was used to study the direct interaction of cells with particles and 3D cell cultures was used to more closely mimic in vivo conditions. The results showed that vimentin was overexpressed in the 2D osteoblasts cultures in presence of metal particles. This might be related to the appearance of pseudotumor in the peri-prosthetic vicinity described in some implanted patients.

Study of overall and local electrochemical responses of oxide films grown on CoCr alloy under biological environments

The interaction of the physiological medium and living tissues with the implant surfaces in biological environments is regulated by biopotentials that induce changes in the chemical composition, structure and thickness of the oxide film. In this work, oxide films grown on CoCr alloys at 0.5 V vs Ag/AgCl and 0.7 V vs Ag/AgCl have been characterized through overall and localized electrochemical techniques in a phosphate buffer solution and 0.3% hyaluronic acid. Nanopores of 10-50nm diameter are homogeneously distributed along the surface in the oxide film formed at 0.7 V vs Ag/AgCl. The distribution of the Constant Phase Element studied by local electrochemical impedance spectroscopy showed a three-dimensional (3D) model on the oxide films grown at 0.5 V vs Ag/AgCl and 0.7 V vs Ag/AgCl. This behaviour is especially noticeable in oxide films grown at 0.7 V vs Ag/AgCl, probably due to surface inhomogeneities, and resistive properties generated by the potentiostatic growth of the oxide film.

Physico-chemical and sensory property changes in almonds of Desmayo Largueta variety during toasting / Cambios en las propiedades físico-químicas y sensoriales de almendras de la variedad Desmayo Largueta durante el tostado

Almonds modify their properties during toasting due to the high temperatures reached. The aim of this study was to evaluate the physico-chemical and sensory property changes in shelled almonds, Desmayo Largueta variety harvested in Tarragona (Spain) and toasted at 200 and 220°C. Internal tem perature and moisture content were determined in almonds during toasting, and fatty acid composi tion, the index of acidity, the peroxide value and the TBA test in almond oil. Sensory analysis of almonds with different toasted intensity was performed. Rancidity was also evaluated by sensory analysis after a year of storage. There was a delay in the internal temperature increase of the almonds between 120 and 130 °C, which coincided with the period of maximum rate of water evaporation. There was no significant variation in the fatty acid composition of the almond oil during toasting. The peroxide value of almond oil had a slight increase from 6 min at 220°C and from 8 min at 200°C, reaching a maximum at 10 min. Rancidity after a year of storage increased up to 8 min and then decreased. The maximum crispiness was obtained at the end of the period of a maximum rate of water evaporation: between 6 and 8 min of toasting at 220 °C and between 8 and 10 min of toasting at 200°C. Over-toasting produced an antioxidant effect in the product, but decreased sweetness and increased bitterness and grittiness.

Classification of patients undergoing weaning from mechanical ventilation using the coherence between heart rate variability and respiratory flow signal

Weaning from mechanical ventilation is still one of the most challenging problems in intensive care. Unnecessary delays in discontinuation and weaning trials that are undertaken too early are both undesirable. This study investigated the contribution of spectral signals of heart rate variability (HRV) and respiratory flow, and their coherence to classifying patients on weaning process from mechanical ventilation. A total of 121 candidates for weaning, undergoing spontaneous breathing tests, were analyzed: 73 were successfully weaned (GSucc), 33 failed to maintain spontaneous breathing so were reconnected (GFail), and 15 were extubated after the test but reintubated within 48 h (GRein). The power spectral density and magnitude squared coherence (MSC) of HRV and respiratory flow signals were estimated. Dimensionality reduction was performed using principal component analysis (PCA) and sequential floating feature selection. The patients were classified using a fuzzy K-nearest neighbour method. PCA of the MSC gave the best classification with the highest accuracy of 92% classifying GSucc versus GFail patients, and 86% classifying GSucc versus GRein patients. PCA of the respiratory flow signal gave the best classification between GFail and GRein patients (79% accuracy). These classifiers showed a good balance between sensitivity and specificity. Besides, the spectral coherence between HRV and the respiratory flow signal, in patients on weaning trial process, can contribute to the extubation decision.

Spectral analysis of the RR series and the respiratory flow signal on patients in weaning process

A considerable number of patients in weaning process have problems to keep spontaneous breathing during the trial and after it. This study proposes to extract characteristic parameters of the RR series and respiratory flow signal according to the patients' condition in weaning test. Three groups of patients have been considered: 93 patients with successful trials (group S), 40 patients that failed to maintain spontaneous breathing (group F), and 21 patients who had successful weaning trials, but that had to be reintubated before 48 hours (group R). The characterization was performed using spectral analysis of the signals, through the power spectral density, cross power spectral density and Coherence method. The parameters were extracted on the three frequency bands (VLF, LF and HF), and the principal statistical differences between groups were obtained in bands of VLF and HF. The results show an accuracy of 76.9% in the classification of the groups S and F.

Support vector machine classification applied on weaning trials patients

One of the most frequent reasons for instituting mechanical ventilation is to decrease patient's work of breathing. Many attempts have been made to increase the effectiveness of the evaluation of the respiratory pattern with the analysis of the respiratory signals. This work proposes a method for the study of the differences in respiratory pattern variability in patients on weaning trials. The proposed method is based on a support vector machine using 35 features extracted from the respiratory flow signal. In this paper, a group of 146 patients with mechanical ventilation were studied: group S of 79 patients with successful weaning trials and group F of 67 patients that failed to maintain spontaneous breathing and were reconnected. Applying a feature selection procedure based on the use of the support vector machine with a leave-one-out cross-validation, it was obtained 86.67% of well classified patients on group S and 73.34% on group F, using only 8 of the 35 features. Therefore, support vector machine can be a classification method of the respiratory pattern variability useful in the study of patients on weaning trials.

The challenge of PRRS immunology

Porcine reproductive and respiratory syndrome (PRRS) is one of the most challenging subjects of research in veterinary viral immunology, and the immune response against PRRS virus (PRRSV) still is poorly understood. Infected pigs develop a strong and rapid humoral response but these initial antibodies do not confer protection and can even be harmful by mediating an antibody-dependent enhancement of disease. In contrast, development of neutralising antibodies (NAs) is delayed and generation of cell-mediated immune responses, such as PRRSV-specific interferon (IFN)-γ secreting cells, is initially erratic. In spite of this, induction of strong and rapid NAs and IFN-γ responses seem to be required for effective vaccination. PRRSV strongly modulates the host’s immune responses. The virus inhibits key cytokines, such as IFN-α, and may induce regulatory cytokines, such as interleukin (IL)-10. Development of NAs seems to be impaired by the existence of a decoy epitope close to the main neutralisation epitope in glycoprotein 5. This ability to modulate the host immune response probably varies among strains or isolates. The genetic diversity of the virus is very high and it has been shown that this diversity can have serious implications for the development of vaccines, since the immunity induced by one strain may be only partial against a different strain, even within the same genotype. With this panorama, the development of newer and universally efficacious PRRSV vaccines is challenging, but the present state of knowledge allows optimism if collaborative efforts are undertaken in the scientific community.

Novel approach to control sulfamethazine misuse in food-producing animals by hair analysis

The presence of sulfamethazine residues in pig and calf hair was compared with the residual levels encountered in the corresponding edible tissues (liver and muscle) as a consequence of drug administration. Sulfamethazine up to 84.7 mg kg-1 was found in calf hair samples after a pharmacological treatment, with a significant effect of hair pigmentation. High concentrations of the parent drug were detected in calf hair for 4 weeks after administration, when sulfamethazine residues were no longer detectable in the corresponding edible tissues. In a similar way, pig hair also accumulated sulfamethazine residues up to 40.5 mg kg-1, which was more than the amount detected in the corresponding muscle and liver samples at slaughter. Hair analysis seems a suitable tool to improve the efficacy of regulatory controls, and thus the safety of the food chain and to discourage the improper use of sulfamethazine in animal farming.

Response surface methodology for the optimization of keratinase production in culture medium containing feathers produced by Kocuria rosea

A 43-fold increase in keratinase production by Kocuria rosea was achieved in batch fermentation using response surface methodology. Factorial designs were used to select the components of a culture medium that showed a significant effect on keratinase production. An orthogonal-central composite experimental design was performed, with only two (feathers and magnesium) from nine initial compounds being further analyzed by response surface methodology. An optimum keratinase production of 14 886.9 U/mg was obtained with the following medium composition (per litre): NH4Cl, 0.3 g; NaCl, 0.3 g; K2HPO4, 3.2 g; KH2PO4, 4.0 g; MgSO4.6H2O, 0.5 g; yeast extract, 0.1 g; and finely milled feathers, 30 g. The medium was shaken at 400 r/min with an incubation period of 14 h at 40 degrees C.

Ternary complex formation between HvMYBS3 and other factors involved in transcriptional control in barley seeds

The SHAQKYF R1MYB transcription factor (TF) HvMYBS3 from barley is an activator of gene expression both during endosperm development and in aleurone cells upon seed germination. Its mRNA was detected as early as 10 days after flowering in developing barley endosperm, with a peak at 18 days, and in aleurone cells at 8 h after water imbibition, as shown by Northern blot and in situ hybridization analyses. The HvMYBS3 protein expressed in bacteria binds to oligonucleotides containing a GATA core derived from the promoters of: (i) the developing endosperm gene Itr1 (5'-GATAAGATA-3') encoding trypsin inhibitor BTI-CMe, and (ii) the post-germinating aleurone gene Amy6.4 (5'-TATCCAC-3'/5'-GTGGATA-3') encoding a high-pI alpha-amylase. Transient expression experiments in co-bombarded developing endosperms and in barley aleurone layers demonstrated that HvMYBS3 trans-activated transcription both from Itr1 and Amy6.4 promoters, in contrast with a previously reported seed-expressed R1MYB, HvMCB1, which was an activator of Itr1 and a transcriptional repressor of the Amy6.4 gene. In the yeast three-hybrid system, the HvMYBS3 protein formed a ternary complex with BPBF and BLZ2, two important seed TFs. However, no binary interactions could be detected between HvMYBS3 and BLZ2 or between HvMYBS3 and BPBF.

Extended coasting duration exerts a negative impact on IVF cycle outcome due to premature luteinization

Coasting, or withholding gonadotrophin administration while maintaining gonadotrophin-releasing hormone analogue until oestradiol drops to a safe concentration, is an alternative approach to prevent ovarian hyperstimulation syndrome (OHSS) in high responder patients. However, the length of this procedure has not been precisely studied. This paper is a retrospective study of 132 patients who showed a high response (oestradiol > 4500 pg/ml and/or more than 20 follicles > 17 mm) to ovarian stimulation and were coasted due to their high risk of developing OHSS, and evaluated the impact of the duration of coasting on IVF cycle outcome. Additionally, serum LH and progesterone concentrations were studied to investigate whether premature luteinization was present in these cycles and whether it might be related to coasting duration. A significant decrease in implantation rate was found when coasting was required for more than 4 days, together with a trend towards a higher cancellation rate. Premature luteinization was significantly elevated in women undergoing coasting compared with control women (34 versus 15.6%, P < 0.05). In the majority of patients who showed premature luteinization, coasting lasted >/=3 days. To conclude, prolonged coasting may affect the endometrium, anticipating the implantation window. These data may explain why some women undergoing extended coasting show a lower implantation rate compared with controls.

Splanchnic Perfusion During Delayed, Hypotensive, or Aggressive Fluid Resuscitation From Uncontrolled Hemorrhage

The purpose of this study was to determine the effect of three different fluid resuscitation strategies on splanchnic perfusion in a clinically relevant model of uncontrolled hemorrhage after liver trauma. Anesthetized swine were instrumented with a gastric near-infrared spectroscopy probe (GStO2), a jejunal tonometer (PrCO2), a portal vein catheter (SpvO2, lactate), and an ultrasonic blood flow probe on the superior mesenteric artery. The liver was lacerated to produce uncontrolled hemorrhage and a shock state characterized by a 40-60% decrease in cardiac output and a decrease in mean arterial pressure (MAP) to 42 +/- 1 mmHg. Animals were randomly assigned to either delayed resuscitation (n = 6); hypotensive resuscitation with lactated Ringer's infusion to MAP = 60 mmHg (n = 6); or aggressive resuscitation with LR to MAP >/= 75 mmHg (n = 6). For the remainder of the protocol, the treatment was identical. The data showed that blood loss (47 +/- 7 and 45 +/- 10 mL/kg) and total fluid requirements (118 +/- 73 and 171 +/- 85 mL/kg) were similar with either hypotensive or aggressive resuscitation. In contrast, with delayed resuscitation, both values were lower (27 +/- 2 mL/kg and 87 +/- 33 mL/kg, both P < 0.05). Despite aggressive resuscitation, SpvO2 and GstO2 were about 10% lower (both P < 0.05 within group) and PrCO2 was about 20 mmHg higher (P < 0.05 within group) than the corresponding values in the other two groups. Thus, delayed resuscitation minimized the blood loss but did not restore tissue oxygenation, whereas aggressive resuscitation was associated with maximal blood loss and splanchnic hypoperfusion. For this reason, it is reasonable to conclude that hypotensive resuscitation might be an effective strategy to maintain splanchnic perfusion after blunt abdominal trauma and uncontrolled hemorrhage.

Leishmaniasis in HIV infection

Herein we review the particular aspects of leishmaniasis associated with HIV infection. The data in this review are mainly from papers identified from PubMed searches and from papers in reference lists of reviewed articles and from the authors' personal archives. Epidemiological data of HIV/Leishmania co-infection is discussed, with special focus on the influence of Highly Active Antiretroviral Therapy (HAART) on incidence of leishmaniasis and transmission modalities. Microbiological characteristics, pathogenesis, clinical presentation and specific treatment of the co-infection are also presented.

Experimental study of bone response to a new surface treatment of endosseous titanium implants

This study examines a new surface treatment that uses coarse calcium phosphate, which provides the benefits of surface roughening without introducing any foreign materials that may become imbedded in the implants. It is intended to enhance the use of implants in areas of inferior bone quality and quantity, such as the posterior areas of the maxilla and the mandible. Implants placed in the tibia of rabbits were removed after 16 weeks and examined microscopically. Pore sizes examined under the scanning electron microscope met the conditions described in the literature for successful integration. Optic microscopy revealed evidence of bone apposition over the roughened implant surface comparable to that seen in other surfaces. There was a definite absence of fibrous tissue, demonstrating good-to-excellent bone contact with the Restore Resorbable Blast Media implants (Lifecore Biomedical, Chaska, MN). In addition, it appears that the blasting of resorbable calcium phosphate on the machine titanium surface results in the resorbable blast media surface acting like an inert material. Further studies with a larger sample size are needed to confirm these initial findings.

Intra- and inter-individual variability in human sperm concentration, motility and vitality assessment during a workshop involving ten laboratories

The aim of the present study was to assess variability in the evaluation of human sperm concentration, motility and vitality. Technicians and biologists from 10 teams involved in multicentre studies on semen quality attended the same laboratory, each team using its own methods and equipment to analyse the same semen samples. Inter-individual variability was assessed from 17 fresh semen samples of varying quality. Intra-individual variability was assessed from pools of frozen samples for sperm concentration and motility and stained smears for vitality with three blind evaluations by sample and smear. The mean inter-individual coefficients of variation were 22.9, 21.8 and 17.5% for sperm concentration, motility and vitality respectively. There was no statistical difference among participants for sperm concentration assessment, but significant differences for both motility and vitality (both P: < 0.05). The mean intra-individual coefficients of variation were 15.8, 26.2 and 13.1% for sperm concentration, motility and vitality respectively, with marked differences between expert and novice participants: concentration 9.8% versus 28.0%; motility 22.8% versus 33.0%; and vitality 10.0% versus 19.3%. The present data confirm the need for external quality control schemes for diagnostic purposes, and indicate their utmost importance in multicentre studies on semen quality.

Adaptation of Spodoptera exigua (Lepidoptera: Noctuidae) to barley trypsin inhibitor BTI-CMe expressed in transgenic tobacco

Nicotiana tabacum plants were transformed with the cDNA of barley trypsin inhibitor BTI-CMe under the control of the 35S CaMV promoter. Although the transgene was expressed and the protein was active in the homozygous lines selected, growth of Spodoptera exigua (Lepidoptera: Noctuidae) larvae reared on transgenic plants was not affected. The protease activity in larval midgut extracts after 2 days feeding on transformed tobacco leaves from the highest expressing plant showed a reduction of 25% in the trypsin-like activity compared to that from insects fed on non-transformed controls. The susceptibility of digestive serine-proteases to inhibition by BTI-CMe was confirmed by activity staining gels. This decrease was compensated with a significant induction of leucine aminopeptidase-like and carboxipeptidase A-like activities, while chymotrypsin-, elastase-, and carboxipeptidase B-like proteases were not affected.

[Intestinal parasites in school children at a public institution in Maracaibo municipality, Venezuela]

To determine the prevalence and epidemiological parameters of intestinal parasites in schoolchildren, a faecal analysis was performed in 349 individuals of both sexes, between 5 and 16 years of age. The methodology used included, a fresh test, formol-ether technique and faecal egg counts by the Kato-Katz method. Eighty three per cent of the children presented enteroparasites, with a high prevalence of polyparasitism (71.6%). There was not significative difference between parasitoses, sex and age. However, it was observed an increase of helminthiasis and protozooses in children between 7 and 10 years of age. The principal enteroparasites founded were: Trichuris trichiura (41.8%), Ascaris lumbricoides (35.2%), Blastocystis hominis (48.1%) and Endolimax nana (22.9%). When the intensity of infestation was studied by the faecal egg counts, it was observed that the highest percentage of children with T. trichiura had light infestations (84.3%), while 45.9% of the children with A. lumbricoides had severe infestations. The Abundance, Mean Intensity and Aggregation Coefficient (k) values show an over-dispersed spatial disposition of both helminths, where only few children harbour heavy burdens and eliminate a large quantity of eggs. This aggregation was higher for T. trichiura (k = 0.298) than for A. lumbricoides (k = 1.138).