Stochastic modeling of Dalbulus maidis, vector of maize diseases.

We developed a simple linear stochastic model for Dalbulus maidis dependent exclusively on temperature, whose parameters were determined from published field and laboratory studies performed at different temperatures. This model takes into account the principal stages and events of the life cycle of this pest, which is vector of maize diseases. We implemented the effect of distributed delays or Linear Chain Trick (LCT) considering a fixed number of sub-stages for egg and nymph stages of Dalbulus maidis in order to accurately represent what is observed in nature. A sensitivity analysis allows us to observe that the speed of the dynamics is sensitive to changes in the development rates, but not to the longevity of each stage or the fecundity, which almost exclusively affect insect abundance. We used our model to study its predictive and explanatory capacity considering a published experiment as a case study. Although the simulation results show a behavior qualitatively equivalent to that observed in the experimental results it is not possible to explain accurately the magnitude, nor the times in which the maximum abundances of second-generation nymphs and adults are reached. Therefore, we evaluated three possible scenarios for the insect that allow us to glimpse some of the advantages of having a computational model in order to find out what processes, taken into account in the model, may explain the differences observed between published experimental results and model results. The three proposed scenarios, based on variations in the parameterized rates of the model, can satisfactorily explain the experimental observations. We observed that in order to better simulate the experimental results it is not necessary to modify fecundity or mortality rates. However, it is necessary to accelerate the average development rates of our model by 20 to 40 %, compatible with extreme values of the rates close to the upper edges of the confidence bands of our parameterization rate curves, according to insects with faster development rates already reported in literature.

Multiresistance to Nonazole Fungicides in Aspergillus fumigatus TR34/L98H Azole-Resistant Isolates.

Drug resistance is a worldwide problem affecting all pathogens. The human fungal pathogen Aspergillus fumigatus coexists in the environment with other fungi targeted by crop protection compounds, being unintentionally exposed to the selective pressure of multiple antifungal classes and leading to the selection of resistant strains. A. fumigatus azole-resistant isolates are emerging in both clinical and environmental settings. Since their approval, azole drugs have dominated clinical treatment for aspergillosis infections and the agriculture fungicide market. However, other antifungal classes are used for crop protection, including benzimidazoles (methyl benzimidazole carbamates [MBCs]), strobilurins (quinolone oxidation inhibitors [QoIs]), and succinate dehydrogenase inhibitors (SDHIs). Mutations responsible for resistance to these fungicides have been widely researched in plant pathogens, but resistance has not been explored in A. fumigatus. In this work, the genetic basis underlying resistance to MBCs, QoIs, and SDHIs was studied in azole-susceptible and -resistant A. fumigatus strains. E198A/Q and F200Y mutations in ß-tubulin conferred resistance to MBCs, G143A and F129L substitutions in cytochrome b conferred resistance to QoIs, and H270R/Y mutations in SdhB conferred resistance to SDHIs. Characterization of susceptibility to azoles showed a correlation between strains resistant to these fungicides and the ones with tandem-repeat (TR)-based azole resistance mechanisms. Whole-genome sequencing analysis showed a genetic relationship among fungicide multiresistant strains, which grouped into subclusters that included only strains carrying the TR-based azole resistance mechanisms, indicating a common ancestor/evolution pattern and confirming the environmental origin of this type of azole-resistant A. fumigatus.

Aspergillus fumigatus and aspergillosis: From basics to clinics.

The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.

Acacia farnesiana pods (plant: Fabaceae) possesses anti-parasitic compounds against Haemonchus contortus in female lambs.

Acacia farnesiana pods are rich in secondary metabolites and their biological activities have been recorded as antibacterial, antioxidant and anthelmintic. Previously, an in vitro bioguided study showed the important ovicidal and larvicidal effects of an organic fraction (EtOAc-F) from a hydroalcoholic extract of A. farnesiana pods against Haemonchus contortus. The present study aimed to assess the in vivo anthelmintic effect of EtOAc-F from A. farnesiana pods on the H. contortus faecal egg elimination in female lambs and on the infective larvae (L3) population reduction in coprocultures. The EtOAc-F was obtained from a hydroalcoholic extract from A. farnesiana pods through chromatographic procedures; additionally, some secondary compounds were identified using high-performance liquid chromatography (HPLC). Twenty-one 'Katahdin' crossbred female lambs ranging from three to four months of age, with body weights 21.9 ± 0.39 kg were used. Animals were orally infected with H. contortus (L3) by a single dose of 350 L3/kg BW. Three experimental groups (n = 7) were assigned as follows: 1) Control (untreated), 2) Albendazole, as a positive control (at 7.5 mg/kg BW, unique dose) and 3) EtOAc-F (at 100 mg/kg BW, once every third day, with three applications in total). Individual faecal samples were collected once a week for 5 weeks (at days 38, 45, 52, 59 and 66) post-treatment, to measure the faecal egg counts (FEC) and to obtain the H. contortus (L3) population from faecal cultures. The highest FEC reduction caused by EtOAc-F was 67.7%; meanwhile, albendazole showed a total FEC reduction after the second week post-treatment (day 45). On the other hand, the fraction caused an important reduction in the larval population in coprocultures (54.3-68.5%). The phytochemical analysis revealed the presence of galloyl derivatives and flavonoids as major compounds. The A. farnesiana pods could serve as a natural anthelmintic for the control of H. contortus, and perhaps for controlling other parasites of veterinary importance.

Galloyl derivatives from Caesalpinia coriaria exhibit in vitro ovicidal activity against cattle gastrointestinal parasitic nematodes.

Gastrointestinal nematodes (GIN) are responsible for enormous economic losses worldwide. The use of anthelmintic drugs reduces the parasitic burden in ruminants. However, the excessive use of these drugs triggers anthelmintic resistance in these parasites, which leads to a worrisome inefficacy of most of the commercially available antiparasitic drugs. Caesalpinia coriaria is an arboreal legume possessing medical properties, although the antiparasitic potential of this plant against animal parasitic nematodes has not yet been studied. The aim of this study was to assess the in vitro ovicidal activity of a hydro-alcoholic extract (HA-E) from C. coriaria fruits against GIN and to identify the compounds responsible for this activity through an egg hatch inhibition (EHI) assay. GIN eggs obtained from cattle faeces were used in bio-guided assays. The HA-E was subjected to a liquid-liquid extraction using water and ethyl acetate to obtain two fractions, an organic fraction (EtOAc-F, 27% yield) and an aqueous (Aq-F, 73% yield) fraction. The chromatographic fractionation of the EtOAc-F (2 gr) was performed on a glass column packed with silica gel and eluted with dichloromethane/methanol with 10% ascending polarity. The bioactive compounds were analysed using high-performance liquid chromatography (HPLC) with UV detection, nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS). The HA-E extract and the EtOAc-F showed ovicidal activity at a LC50 of 0.92 and 0.16 mg/mL, respectively. A concentration-dependant effect was observed in both treatments. Chromatographic fractionation of the EtOAc-F, allowed for the isolation and characterisation of three important compounds: methyl gallate (1), gallic acid (2) and an unidentified compound (UC). The bioactive molecules (2 and UC) displayed an ovicidal activity close to 100% at 1 mg/mL concentration. The results of this work show that gallic acid (2) isolated from C. coriaria fruits is responsible for its ovicidal activity. The use of Caesalpinia coriaria could be explored in future studies as an environmentally-friendly alternative for the control of GIN in ruminants.

Simplification to dual therapy (atazanavir/ritonavir + lamivudine) versus standard triple therapy [atazanavir/ritonavir + two nucleos(t)ides] in virologically stable patients on antiretroviral therapy: 96 week results from an open-label, non-inferiority, randomized clinical trial (SALT study).

OBJECTIVES: We evaluated whether maintenance therapy with atazanavir/ritonavir plus lamivudine (ATV/r + 3TC) was non-inferior to ATV/r plus two nucleosides (ATV/r + 2NUCs) at 96 weeks of follow-up. METHODS: SALT is a multicentre, open-label, non-inferiority clinical trial in HIV-1-infected virologically suppressed patients. Hepatitis B virus surface antigen-negative subjects with no previous treatment failure/resistance mutations and HIV-1-RNA <50 copies/mL for ≥6 months were randomized (1 : 1) to ATV/r + 3TC or ATV/r + 2NUCs. The primary endpoint was HIV-1-RNA <50 copies/mL in the PP population. Non-inferiority was demonstrated if the lower bound of the 95% CI for the difference was not below -12%. RESULTS: Some 286 patients were analysed. At week 96, 74.4% had HIV-1-RNA <50 copies/mL in the ATV/r + 3TC arm versus 73.9% in the ATV/r + 2NUCs arm (95% CI for the difference, -9.9%-11.0%). In both groups, similar values were observed for patients with confirmed virological failure in ATV/r + 3TC versus ATV/r + 2NUCs (9 versus 5), death (1 versus 0), discontinuation due to ART-related toxicity (7 versus 11), withdrawal from the study (7 versus 9) and loss to follow-up (6 versus 6). One patient taking ATV/r + 2NUCs developed resistance mutations (M184V and L63P). Similar values were obtained for change in mean CD4 count [19 versus 18 cells/mm3 (95% CI for the difference, -49.3-50.7), grade 3-4 adverse events (70.7% versus 70.2%) and changes in the global deficit score, -0.3 (95% CI, -0.5 to -0.1) for ATV/r + 3TC, versus -0.2 (95% CI, -0.4 to -0.1) for ATV/r + 2NUCs]. CONCLUSIONS: The long-term results of switching to ATV/r + 3TC show that this strategy is effective, safe and non-inferior to ATV + 2NUCs in virologically suppressed HIV-infected patients.

Phase Diagram of Fatty Acid Langmuir Monolayers from Rheological Measurements.

Langmuir monolayers of fatty acids and alcohols are two-dimensional systems with a rich equilibrium phase diagram. We have explored the temperature and surface-pressure-dependent shear response of monolayers formed by fatty acids of different chain lengths and a fatty alcohol. This has been accomplished with an interfacial shear rheometer utilizing magnetic tweezers and equipped with a refined temperature control and acquisition system. Our rheological results have allowed us to draw a phase diagram from the viscoelastic properties of these 2-D systems and show new phenomena that strongly depend on temperature: the existence of a maximum in viscosity at the L2' phase, the behavior of the elastic modulus to the storage modulus ratio at the L2 phase, and the increase or decrease in viscosity at the L2-LS phase transition. In addition, we unambiguously show that the LS phase displays a counterintuitive behavior in which the loss modulus increases with temperature. We demonstrate, through isothermal surface pressure sweeps and isobaric temperature sweeps, that the exponential dependence of the loss modulus on temperature at the LS phase appears for all hydrophobic tail lengths studied and for both acid and alcohol head groups.

Toward a comprehensive care of HIV patients: finding a strategy to detect depression in a Spanish HIV cohort.

Depression is a common but frequently undiagnosed feature in individuals with HIV infection. To find a strategy to detect depression in a non-specialized clinical setting, the overall performance of the Hospital Anxiety and Depression Scale (HADS) and the depression identification questions proposed by the European AIDS Clinical Society (EACS) guidelines were assessed in a descriptive cross-sectional study of 113 patients with HIV infection. The clinician asked the two screening questions that were proposed under the EACS guidelines and requested patients to complete the HADS. A psychiatrist or psychologist administered semi-structured clinical interviews to yield psychiatric diagnoses of depression (gold standard). A receiver operating characteristic (ROC) analysis for the HADS-Depression (HADS-D) subscale indicated that the best sensitivity and specificity were obtained between the cut-off points of 5 and 8, and the ROC curve for the HADS-Total (HADS-T) indicated that the best cut-off points were between 12 and 14. There were no statistically significant differences in the correlations of the EACS (considering positive responses to one [A] or both questions [B]), the HADS-D ≥ 8 or the HADS-T ≥ 12 with the gold standard. The study concludes that both approaches (the two EACS questions and the HADS-D subscale) are appropriate depression-screening methods in HIV population. We believe that using the EACS-B and the HADS-D subscale in a two-step approach allows for rapid, assumable and accurate clinical diagnosis in non-psychiatric hospital settings.

In vitro gas production of foliage from three browse tree species treated with different dose levels of exogenous fibrolytic enzymes.

The aim of this study was to evaluate the effect of different dose levels of exogenous fibrolytic enzymes (EFE) on in vitro ruminal fermentation kinetics and energy utilization of foliages from three browse trees (Pithecellobium dulce, Heliocarpus velutinus and Guazuma ulmifolia). Mixture of EFE product was added to the leaves of the three browse tree species at three dose levels: 0 (control), 3.5 and 7.0 mg/g of DM. Chemical composition of the foliages, including plant secondary metabolites such as total phenolics (TP), saponins (SAP) and aqueous fraction (AF), was determined. In addition, in vitro assaying of ruminal gas production kinetics was determined for the three browse three foliages treated with EFE. P. dulce had the highest crude protein content (p < 0.05), whereas G. ulmifolia had the highest content of neutral detergent fibre and SAP (p < 0.05) and H. velutinus had the lowest content of TP (p < 0.05). The interaction between tree species and dose level of EFE was significant (p < 0.05) for gas production (GP) at 24 h of incubation, parameters b and c of the accumulated GP curve, short-chain fatty acids (SCFA) and metabolizable energy (ME). The lowest (p < 0.01) extent of accumulated GP as well as the b and c values occurred in G. ulmifolia at 0 mg EFE/g DM. P. dulce had the highest (p < 0.05) values for ME and SCFA at the highest dose of EFE. Tree species and dose level had significant (p < 0.05) effects on all parameters describing in vitro ruminal fermentation kinetics and energy utilization. Addition of EFE improved the fermentation kinetics of the browse species considered in this study.

Factors associated with in-hospital delays in treating acute stroke with intravenous thrombolysis in a tertiary centre. / Identificación de los factores que influyen en el retraso intrahospitalario del inicio de trombólisis intravenosa en el ictus agudo en un hospital terciario.

OBJECTIVE: This study aims to determine which factors are associated with delays in door-to needle (DTN) time in our hospital. This will help us design future strategies to shorten time to treatment with intravenous thrombolysis (IVT). METHODS: Retrospective analysis of a prospective cohort of patients with ischaemic stroke treated with IVT in our hospital between 2009 and 2012. We analysed the relationship between DTN time and the following variables: age, sex, personal medical history, onset-to-door time, pre-hospital stroke code activation, blood pressure and blood glucose level, National Institutes of Health Stroke Scale (NIHSS), computed tomography angiography (CTA) and/or doppler/duplex ultrasound (DUS) performed before IVT, time to hospital arrival, and day of the week and year of stroke. RESULTS: Our hospital treated 239 patients. Median time to treatment in minutes (IQR): onset-to-door, 84 (60-120); door-to-CT, 17 (13-24.75); CT-to needle, 34 (26-47); door-to-needle, 52 (43-70); onset-to-needle, 145 (120-180). Door-to-needle time was significantly shorter when code stroke was activated, at 51 vs. 72min (P=0.008), and longer when CTA was performed, at 59 vs. 48.5min (P=0.004); it was also longer with an onset-to-door time<90min, at 58 vs. 48min (P=0.003). The multivariate linear regression analysis detected 2 factors affecting DTN: code stroke activation (26.3% reduction; P<0.001) and onset-to-door time (every 30min of onset-to-door delay corresponded to a 4.7min increase in DTN time [P=0.02]). On the other hand, CTA resulted in a 13.4% increase in DTN (P=0.03). No other factors had a significant influence on door-to-needle time. CONCLUSIONS: This study enabled us to identify CTA and the «3-hour effect¼ as the 2 factors that delay IVT in our hospital. In contrast, activating code stroke clearly reduces DTN. This information will be useful in our future attempts to reduce door-to-needle times.

Rapid development of Candida krusei echinocandin resistance during caspofungin therapy.

In invasive candidiasis, there has been an epidemiological shift from Candida albicans to non-albicans species infections, including infections with C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei. Although the prevalence of C. krusei remains low among yeast infections, its intrinsic resistance to fluconazole raises epidemiological and therapeutic concerns. Echinocandins have in vitro activity against most Candida spp. and are the first-line agents in the treatment of candidemia. Although resistance to echinocandin drugs is still rare, individual cases of C. krusei resistance have been reported in recent years, especially with strains that have been under selective pressure. A total of 15 C. krusei strains, isolated from the blood, urine, and soft tissue of an acute lymphocytic leukemia patient, were analyzed. Strains developed echinocandin resistance during 10 days of caspofungin therapy. The molecular epidemiology of the isolates was investigated using two different typing methods: PCR-based amplification of the species-specific repetitive polymorphic CKRS-1 sequence and multilocus sequence typing. All isolates were genetically related, and the mechanism involved in decreased echinocandin susceptibility was characterized. Clinical resistance was associated with an increase in echinocandin MICs in vitro and was related to three different mutations in hot spot 1 of the target enzyme Fks1p. Molecular evidence of the rapid acquisition of resistance by different mutations in FKS1 highlights the need to monitor the development of resistance in C. krusei infections treated with echinocandin drugs.

Switching from zidovudine/lamivudine to tenofovir/emtricitabine improves fat distribution as measured by fat mass ratio.

OBJECTIVES: Fat mass ratio (FMR) has been suggested as an objective indicator of abnormal body fat distribution in HIV infection. Although it could provide more comprehensive information on body fat changes than limb fat mass, FMR has scarcely been used in clinical trials examining body fat distribution in HIV-infected patients. METHODS: A subanalysis of a controlled, randomized clinical trial in virologically suppressed HIV-1-infected men switching from zidovudine (ZDV)/lamivudine (3TC) to emtricitabine (FTC)/tenofovir (TDF) versus continuing on ZDV/3TC was carried out. FMR was assessed by dual X-ray absorptiometry (DEXA) for a period of 72 weeks. Lipoatrophy was defined as FMR ≥ 1.5. Multivariate linear regression models for the change in FMR from baseline were fitted. RESULTS: Sixty-five men were randomized and treated (28 in the FTC/TDF arm and 37 in the ZDV/3TC arm), and 57 completed the study (25 and 32 in each arm, respectively). In the FTC/TDF arm, adjusted mean FMR decreased by 0.52 at week 72 (P = 0.014), and in the ZDV/3TC arm it increased by 0.13 (P = 0.491; P between arms = 0.023). Among subjects with lipoatrophy (baseline FMR ≥ 1.5), adjusted FMR decreased by 0.76 (P = 0.003) in the FTC/TDF arm and increased by 0.21 (P = 0.411; P between arms = 0.009) in the ZDV/3TC arm. Baseline FMR and treatment group were significant predictors (P < 0.05) of post-baseline changes in FMR. CONCLUSIONS: Switching from ZDV/3TC to FTC/TDF led to an improvement in FMR, compared with progressive worsening of FMR in subjects receiving ZDV/3TC, showing that fat mass not only increased but was also distributed in a healthier way after the switch.

Magnetic microwire probes for the magnetic rod interfacial stress rheometer.

The magnetic needle interfacial shear rheometer is a valuable tool for the study of the mechanical properties of thin fluid films or monolayers. However, it is difficult to differentiate the interfacial and subphase contributions to the drag on the needle. In principle, the problem can be addressed by decreasing the needle diameter, which decreases the bulk contribution while the interfacial contribution remains essentially the same. Here we show the results obtained when using a new type of needle, that of magnetic microwires with diameter approximately 10 times thinner than for commercial needles. We show that the lower inertia of the microwires calls for a new calibration procedure. We propose such a new calibration procedure based on the flow field solution around the needle introduced in refs 1 and 2. By measuring thin silicone oil films with well-controlled interfacial viscosities as well as eicosanol (C20) and pentadecanoic acid (PDA, C15) Langmuir monolayers, we show that the new calibration method works well for standard needles as well as for the microwire probes. Moreover, we show that the analysis of the force terms contributing to the force on the needle helps to ascertain whether the measurements obtained are reliable for given surface shear viscosity values. We also show that the microwire probes have at least a 10-fold-lower resolution limit, allowing one to measure interfacial viscosities as low as 10(-7) N·m/s.

Spontaneous spinal epidural haematoma: a retrospective study of a series of 13 cases.

INTRODUCTION: Spontaneous spinal epidural haematoma (SSEH) has an estimated incidence of one per million inhabitants. It is classified as spontaneous when no identifiable cause can be linked to its onset. OBJECTIVE: To describe a sample of patients with SSEH and analyse variables related to its functional prognosis. PATIENTS AND METHODS: Retrospective study carried out in patients diagnosed with SSEH between 2001 and 2013 in our hospital. RESULTS: We included 13 subjects (7 men) with a mean age of 71 years. Of the total, 62% had hypertension and 54% were treated with oral anticoagulants; of the latter, 57% had an International Normalised Ratio above 3. The most frequent manifestation was spinal column pain (85%). Nearly all subjects presented an associated neurological deficit, whether sensory-motor (70%), pure motor (15%), or pure sensory (7%). Five patients underwent surgical treatment and 8 had conservative treatment. After one year, 3 of the patients treated surgically and 4 of those on conservative treatment had a score of 2 or lower on the modified Rankin Scale. Poorer prognosis was observed in patients with anticoagulant therapy, large haematomas, location in the lumbar region, and more pronounced motor disability at onset. CONCLUSIONS: Old age, hypertension, and anticoagulant therapy are the main risk factors for SSEH. The typical presentation consists of back pain with subsequent motor deficit. In patients with established motor symptoms, surgical treatment within the first 24hours seems to be the best option.

Interpreting the reasons for the choice and changing of two drug regimens in an observational cohort: comparison of a ritonavir-boosted protease inhibitor-based versus a nonnucleoside reverse transcriptase inhibitor-based first-line regimen.

OBJECTIVES: We compared reasons for the choice of regimen, time to and reasons for third drug modification, virological response and change in CD4 T-cell counts in patients started on atazanavir/ritonavir (ATV/r)- vs. efavirenz (EFV)-based first-line regimens. METHODS: We included patients from the Cohort of the Spanish HIV Research Network (CoRIS), a multicentre cohort of HIV-positive treatment-naïve subjects, in the study. We used logistic regression to assess factors associated with choosing ATV/r vs. EFV, proportional hazards models on the subdistribution hazard to estimate subdistribution hazard ratios (sHRs) for third drug modification, logistic regression to estimate odds ratios (ORs) for virological response and linear regression to assess mean differences in CD4 T-cell count increase from baseline. RESULTS: Of 2167 patients, 10.7% started on ATV/r. ATV/r was more likely than EFV to be prescribed in injecting drug users [adjusted OR 1.85; 95% confidence interval (CI) 1.03-3.33], in 2009-2010 (adjusted OR 1.63; 95% CI 1.08-2.47) and combined with abacavir plus lamivudine (adjusted OR 1.53; 95% CI 0.98-2.43). Multivariate analyses showed no differences, comparing ATV/r vs. EFV, in the risk of third drug modification (sHR 1.04; 95% CI 0.74-1.46) or in virological response (OR 0.81; 95% CI 0.46-1.41); differences in mean CD4 T-cell count increase from baseline were at the limit of statistical significance (mean difference 29.8 cells/µL; 95% CI -4.1 to 63.6 cells/µL). In patients changing from EFV, 48% of changes were attributable to toxicity/adverse events, 16% to treatment failure/resistance, 3% to simplification, and 8 and 12%, respectively, to patients' and physicians' decisions; these percentages were 24, 6, 12, 14 and 24%, respectively, in those changing from ATV/r. CONCLUSIONS: ATV/r- and EFV-based regimens meet the requirements of both efficacy and safety for initial combination antiretroviral regimen, which relate to better durability.

Relationship of children's salivary microbiota with their caries status: a pyrosequencing study.

PURPOSE: Different dental caries status could be related with alterations in oral microbiota. Previous studies have collected saliva as a representative medium of the oral ecosystem. The purpose of this study was to assess the composition of oral microbiota and its relation to the presence of dental caries at different degrees of severity. MATERIALS AND METHODS: One hundred ten saliva samples from 12-year-old children were taken and divided into six groups defined in strict accordance with their dental caries prevalence according to the International Caries Detection and Assessment System II criteria. These samples were studied by pyrosequencing PCR products of the 16S ribosomal RNA gene. RESULTS: The results showed statistically significant intergroup differences at the class and genus taxonomic levels. Streptococcus is the most frequent genus in all groups; although it did not show intergroup statistical differences. In patients with cavities, Porphyromonas and Prevotella showed an increasing percentage compared to healthy individuals. Bacterial diversity diminished as the severity of the disease increased, so those patients with more advanced stages of caries presented less bacterial diversity than healthy subjects. CONCLUSION: Although microbial composition tended to be different, the intragroup variation is large, as evidenced by the lack of clear intragroup clustering in principal component analyses. Thus, no clear differences were found, indicating that using bacterial composition as the sole source of biomarkers for dental caries may not be reliable in the unstimulated saliva samples used in the current study.

Workload of on-call emergency room neurologists in a Spanish tertiary care centre. A one-year prospective study.

INTRODUCTION: Population ageing, the rising demand for healthcare, and the establishment of acute stroke treatment programs have given rise to increases in the number and complexity of neurological emergency cases. Nevertheless, many centres in Spain still lack on-call emergency neurologists. METHODS: We conducted a retrospective study to describe the role of on-call neurologists at Hospital General Universitario Gregorio Marañón, a tertiary care centre in Madrid, Spain. Sociodemographic characteristics, most common pathologies, diagnostic tests, and destination of the patients attended were recorded daily using a computer database. Results were compared with the general care data from the emergency department. RESULTS: The team attended 3234 patients (3.48% of the emergency department total). The mean number of patients seen per day was 11.15. The most frequent pathologies were stroke (34%), epilepsy (16%) and headache (8%). The mean stay in the emergency department was 7.17 hours. Hospital admission rate was 40% (7.38% of emergency hospital admissions). The main destinations for admitted patients were the stroke unit (39.5%) and the neurology department (33%). Endovascular or thrombolytic therapies were performed on 76 occasions. Doctors attended 70% of the patients during on-call hours. CONCLUSIONS: Emergency neurological care is varied, complex, and frequently necessary. Neurological cases account for a sizeable percentage of both patient visits to the emergency room and the total number of emergency admissions. The current data confirm that on-call neurologists available on a 24-hour basis are needed in emergency departments.

[Clinico-epidemiological characteristics of acute respiratory infections caused by coronavirus OC43, NL63 and 229E]. / Características de las infecciones respiratorias agudas causadas por los coronavirus OC43, NL63 y 229E.

BACKGROUND AND OBJECTIVES: Acute respiratory infection is a very common condition in the general population. The majority of these infections are due to viruses. This study attempted to determine the clinical and epidemiological characteristics of adult patients with respiratory infection by the coronavirus OC43, NL63 and 229E. PATIENTS AND METHODS: Between January 2013 and February 2014, we prospectively studied all patients with suspected clinical respiratory infection by taking throat swabs and performing a reverse transcription polymerase chain reaction in search of coronavirus. RESULTS: In 48 cases (7.0% of the 686 enrolled patients; 12.6% of the 381 in whom a virus was detected) the presence of a coronavirus demonstrated. In 24 cases, the virus was OC43 (50%); in 14 cases, the virus was NL63 (29%); and in 10 cases, the virus was 229E (21%). The mean age was 54.5 years, with a slight predominance of men. The most common clinical presentations were nonspecific influenza symptoms (43.7%), pneumonia (29.2%) and chronic obstructive pulmonary disease exacerbation (8.3%). Fifty-two percent of the patients required hospitalization, and 2 patients required intensive care. There were no deaths. CONCLUSION: Acute respiratory infections caused by coronavirus mainly affect middle-aged male smokers, who are often affected by previous diseases. The most common clinical picture has been nonspecific influenza symptoms.

Structural changes in layers of lipid mixtures at low surface tensions.

Layers of pulmonary lipids on an aqueous substrate at non-equilibrium conditions can decrease the surface tension of water to quite low values. This is connected with different relaxation processes occurring at the interface and the associated changes in the surface layer structure. Results of measurements by the combination of methods like surface rheology, ellipsometry, Brewster angle microscopy, and IRRAS for spread layers of lipid mixtures open a possibility to specify the dynamics of structural changes at conditions close to the physiological state. At sufficiently low surface tension values (below 5 mN/m) significant changes in the ellipsometric signal were observed for pure DPPC layers, which can be related to a transition from 2D to 3D structures caused by the layer folding. The addition of other lipids can accelerate the relaxation processes connected with squeezing-out of molecules or multilayer stacks formation hampering thereby a decrease of surface tension down to low values corresponding to the folding of the monolayer.

Infection of mice by the enteroaggregative E. coli strain 042 and two mutant derivatives overexpressing virulence factors: impact on disease markers, gut microbiota and concentration of SCFAs in feces.

Several pathogenic Escherichia coli strains cause diarrhea. Enteroaggregative E. coli (EAEC) strains are one of the diarrheagenic pathotypes. EAEC cells form a "stacked-brick" arrangement over the intestinal epithelial cells. EAEC isolates express, among other virulence determinants, the AggR transcriptional activator and the aggregative adherence fimbriae (AAF). Overexpression of the aggR gene results in increased expression of virulence factors such as the aff genes, as well as several genes involved in specific metabolic pathways such as fatty acid degradation (fad) and arginine degradation (ast). To support the hypothesis that induction of the expression of some of these pathways may play a role in EAEC virulence, in this study we used a murine infection model to evaluate the impact of the expression of these pathways on infection parameters. Mice infected with a mutant derivative of the EAEC strain 042, characterized by overexpression of the aggR gene, showed increased disease symptoms compared to those exhibited by mice infected with the wild type (wt) strain 042. Several of these symptoms were not increased when the infecting mutant, which overexpressed aggR, lacked the fad and ast pathways. Therefore, our results support the hypothesis that different metabolic pathways contribute to EAEC virulence.