Quality evaluation of microscopy and scanned histological images for diagnostic purposes

In this work we present a study for assessing and comparing the fidelity of biopsy and cytology images captured with two different devices, that is optical microscopes and scanners, at 40× magnification in bright field. The devices use different ways to magnify images. Microscopes use a set of lenses while scanners capture light through arrays of micro-photoreceptors. The objective is to carry out a quantitative evaluation to discern which of the two devices provides better image quality in terms of contrast, colour and stain. Since there is no unanimous consensus on quality metrics, we will make use of both an objective metric based on perceptual features, together with a subjective psychophysical test as the International Telecommunications Union (ITU) recommends in ITU-R BT.500 for such type of tests. Both techniques indicate a slight preference for the scanner over the microscope in terms of better image quality, considering defocus as the main problem followed by colour distortions. However, the image quality of both devices is suitable for clinical, educational and research purposes.

Lesions confined to the sphenoid ridge: differential diagnosis and surgical treatment

Tumors confined to the sphenoid ridge with little or no extradiploic extension are very rare; we describe here five patients with these lesions. Three were females and two males, with an average age of 33.4 years; the clinical presentation included proptosis and facial deformity. The diagnoses were three meningiomas (one "en plaque," one globous, and one intraosseous) and two fibrous dysplasias (compact form). Although the radiological findings were similar, we could find some details to establish the differential diagnosis before the surgical procedure. All the lesions were totally removed without complications. In a follow-up period of 15 to 36 months none of the lesions has shown clinical or radiological evidence of recurrence. We discuss the pathophysiology of each case, and propose the pterional orbito-zygomatic approach as the best way to resect lesions in this location.

Two new phospholipase D isoforms of Loxosceles laeta: cloning, heterologous expression, functional characterization, and potential biotechnological application

Toxin phospholipases-D present in the venom of Loxosceles spiders is the principal responsible for local and systemic effects observed in the loxoscelism. In this study, we describe the cloning, expression, functional evaluation, and potential biotechnological application of cDNAs, which code for two new phospholipase D isoforms, LIPLD1 and LIPLD2, of the spider Loxosceles laeta. The recombinant protein rLIPLD1 had hydrolytic activity on sphingomyelin and in vitro hemolytic activity on human red blood cells, whereas rLIPLD2 was inactive. The purified recombinant proteins and the venom are recognized by polyclonal anti-rLIPLD1 and rLIPLD2 sera produced in animals and conferred immunoprotection against the venom. These new isoforms reinforce the importance of the multigene family of phospholipases-D present in Loxosceles spiders. A highly immunogenic inactive isoform such as rLIPLD2 raises important expectation for its use as a potential immunogenic inducer of the immunoprotective response to the toxic action of the venom of Loxosceles laeta.

Effects of the substituents on the reactivity of carbonyl oxides. A theoretical study on the reaction of substituted carbonyl oxides with water

The reactions between fifteen carbonyl oxides and water have been investigated with the aim of contributing to a better understanding of the effects of the substituents in the reactivity of carbonyl oxides. We have employed density functional theory and large scale ab initio methods (CCSD(T), CASSCF, and CASPT2), combined with transition state theory, to investigate the addition of water to carbonyl oxide and, for those carbonyl oxides having a methyl substituent in syn, the hydrogen transfer from the methyl group to the terminal oxygen of carbonyl oxide. In this case, the water acts as a catalyst and this reaction can contribute to the atmospheric formation of a hydroxyl radical. Carbonyl oxides with electron withdrawing substituents and zwitterionic character have low energy barriers and react fast, whereas carbonyl oxides with electron releasing substituents have high energy barriers and react slowly. The position of the substituents plays also an important role and carbonyl oxides having a hydrogen atom substituent in syn react faster than carbonyl oxides having a hydrogen atom substituent in anti. The differences in the reactivity of different substituted carbonyl oxides raise up to ten orders of magnitude and the branching ratios for the two different reactions investigated are also reported.

Open or laparoscopic nephrectomy and extracoroporeal repair of complicated renal artery aneurysms: techniques for renal salvage

Renal artery aneurysm is an infrequently seen disease. The most feared symptom is rupture, which is often rapidly fatal. Indications for intervention include size, intractable symptoms and pregnancy. Many cases are managed by endovascular techniques; however, very complex cases often are referred to the urologist. We report our experience with the rarely used technique of renal artery aneurysms repair comprised of nephrectomy, extracorporeal vascular reconstruction with aneurysmectomy, and autotransplant.

[Upper urinary tract tumors: endourological management and treatment]

The propensity of upper tract transitional cell carcinoma towards recurrence and the limitations of upper tract endoscopy have led to nephroureterectomy being the gold standard treatment, even though major open surgery risks outweigh the risks of cancer. Thus, removal of the entire unit may not be warranted when the tumor can be safely controlled endoscopically. Recent advances in technology and techniques have permitted the effective endourologic management of upper transitional cell carcinoma.

[Laparoscopic radical cystectomy and orthotopic urinary diversion in the male patient: technique]

Radical cystectomy with extended pelvic lymphadenectomy remains the treatment of choice for muscle invasive bladder cancer and non-metastatic chorion-invasive high grade tumors resistant to treatment with intravesical chemotherapy. During the last decade the procedure has been refined and we have acquired the skills necessary to perform it using the laparoscopic approach. In this way, the oncologic and functional outcomes obtained can be compared to those of its open counterpart. This article describes in detail the technique of radical cystoprostatectomy and urinary diversion in the male patient conducted by our group in an attempt to improve the knowledge and spread of this always difficult procedure.

Ion transfer through solvent polymeric membranes driven by an exponential current flux

General analytical equations which govern ion transfer through liquid membranes with one and two polarized interfaces driven by an exponential current flux are derived. Expressions for the transient and stationary E-t, dt/dE-E and dI/dE-E curves are obtained, and the evolution from transient to steady behaviour has been analyzed in depth. We have also shown mathematically that the voltammetric and stationary chronopotentiometric I(N)-E curves are identical (with E being the applied potential for voltammetric techniques and the measured potential for chronopotentiometric techniques), and hence, their derivatives provide identical information.

Electron-induced rippling in graphene

We show that the interaction between flexural phonons, when corrected by the exchange of electron-hole excitations, may drive the graphene sheet into a quantum critical point characterized by the vanishing of the bending rigidity of the membrane. Ripples arise then due to spontaneous symmetry breaking, following a mechanism similar to that responsible for the condensation of the Higgs field in relativistic field theories, and leading to a zero-temperature buckling transition in which the order parameter is given by the square of the gradient of the flexural phonon field.

The role of oxidative stress in the pathophysiology of hypertension

Hypertension is considered to be the most important risk factor in the development of cardiovascular disease. An increasing body of evidence suggests that oxidative stress, which results in an excessive generation of reactive oxygen species (ROS), has a key role in the pathogenesis of hypertension. The modulation of the vasomotor system involves ROS as mediators of vasoconstriction induced by angiotensin II, endothelin-1 and urotensin-II, among others. The bioavailability of nitric oxide (NO), which is a major vasodilator, is highly dependent on the redox status. Under physiological conditions, low concentrations of intracellular ROS have an important role in the normal redox signaling maintaining vascular function and integrity. However, under pathophysiological conditions, increased levels of ROS contribute to vascular dysfunction and remodeling through oxidative damage. In human hypertension, an increase in the production of superoxide anions and hydrogen peroxide, a decrease in NO synthesis and a reduction in antioxidant bioavailability have been observed. In turn, antioxidants are reducing agents that can neutralize these oxidative and otherwise damaging biomolecules. The use of antioxidant vitamins, such as vitamins C and E, has gained considerable interest as protecting agents against vascular endothelial damage. Available data support the role of these vitamins as effective antioxidants that can counteract ROS effects. This review discusses the mechanisms involved in ROS generation, the role of oxidative stress in the pathogenesis of vascular damage in hypertension, and the possible therapeutic strategies that could prevent or treat this disorder.

Prevalence and factors associated with significant liver fibrosis assessed by transient elastometry in HIV/hepatitis C virus-coinfected patients

Transient elastometry (TE) could provide a more accurate evaluation of the frequency and risk factors of liver fibrosis in hepatitis C virus (HCV) infection than that based on biopsy. The aim of this study was to assess the prevalence of and factors associated with significant liver fibrosis in a large population of HIV/HCV-coinfected patients. HIV/HCV-coinfected patients, who had participated in a cross-sectional, multicenter, retrospective study of liver fibrosis using noninvasive markers and in whom a determination of liver stiffness (LS) by TE was available, were included in this analysis. Factors potentially associated with significant fibrosis (LS ≥ 9 kPa) were analyzed. One thousand three hundred and ten patients fulfilled the inclusion criteria, 526 (40%) of them showed LS ≥ 9 kPa and 316 (24%) cirrhosis (LS ≥ 14 kPa). The factors independently associated with significant fibrosis [adjusted odds ratio (95% confidence interval, P value) were the following: older age [1.04 (1.01-1.07), 0.002], daily alcohol intake > 50 g/day [1.58 (1.10-2.27), 0.013] and the length of HCV infection [1.03 (1.00-1.06), 0.023]]. A CD4 cell count lower than < 200 per mm(3) [1.67 (0.99-2.81), 0.053] and HCV genotype 4 [0.66 (0.42-1.02), 0.066] were marginally associated with LS ≥ 9 kPa. In conclusion, the prevalence of cirrhosis in HIV/HCV-coinfected patients seems to be higher than previously reported in studies based on liver biopsy. Older age, alcohol consumption and lower CD4 cell counts are related with significant fibrosis. The latter association supports an earlier starting of antiretroviral therapy in this setting.

Event recognition using signal spectrograms in long pulse experiments

As discharge duration increases, real-time complex analysis of the signal becomes more important. In this context, data acquisition and processing systems must provide models for designing experiments which use event oriented plasma control. One example of advanced data analysis is signal classification. The off-line statistical analysis of a large number of discharges provides information to develop algorithms for the determination of the plasma parameters from measurements of magnetohydrodinamic waves, for example, to detect density fluctuations induced by the Alfvén cascades using morphological patterns. The need to apply different algorithms to the signals and to address different processing algorithms using the previous results necessitates the use of an event-based experiment. The Intelligent Test and Measurement System platform is an example of architecture designed to implement distributed data acquisition and real-time processing systems. The processing algorithm sequence is modeled using an event-based paradigm. The adaptive capacity of this model is based on the logic defined by the use of state machines in SCXML. The Intelligent Test and Measurement System platform mixes a local multiprocessing model with a distributed deployment of services based on Jini.

Tetracycline and penicillin resistant Clostridium perfringens isolated from the fangs and venom glands of Loxosceles laeta: its implications in loxoscelism treatment

The venom of Loxosceles spiders produces severe dermonecrotic damage, intravascular hemolysis, systemic alterations and risk of death. Clostridium perfringens is present in the microbial flora of the fangs and venom glands of Loxosceles intermedia. Its inoculation with the venom may infect the wound site and exacerbate the dermonecrotic damage. This anaerobic bacterium is widely distributed in nature and capable of damage with similar characteristics and severity to the spider venom. In this study we isolated and characterized species of Clostridium from the fangs and venom glands of Loxosceles laeta, including C. perfringens. The sensitivity patterns of different isolates of C. perfringens were evaluated by minimum inhibitory concentration against penicillin, ampicillin, erythromycin, gentamicin, chloramphenicol, clindamycin and tetracycline, under anaerobic conditions, using the method of microdilution in broth. Strain C. perfringens H28 showed resistance to penicillin, ampicillin, tetracycline and chloramphenicol. Resistance to penicillin and ampicillin was mediated by beta-lactamase. In vivo evaluation of dermonecrosis in rabbits using L. laeta venom co-inoculated with isolate C. perfringens H28 produced an increase in the area of dermonecrotic lesions in the presence of penicillin and tetracycline, but not with gentamicin. Antibiotic therapy Loxosceles poisoning should be re-evaluated, considering the existence of multi-resistant strains of C. perfringens.

Reduction in catheter-related bloodstream infections in critically ill patients through a multiple system intervention

In this study, we aimed to determine the utility of a multiple system intervention to reduce catheter-related bloodstream infections (CR-BSI) in our intensive care unit (ICU). A prospective cohort study was undertaken in the medical and surgical ICU at a university hospital. We applied five measures: educational sessions about inserting and maintaining central venous catheters, skin cleaning with chlorhexidine, a checklist during catheter insertion, subclavian vein insertion and avoiding femoral insertion whenever possible, and removing unnecessary catheters. We determined the rate of CR-BSI per 1,000 catheter-days during the intervention (March to December 2007) and compared it with the rate during the same period in 2006 in which we applied only conventional preventive measures. CR-BSI was defined as the recovery of the same organism (same species, same antibiotic susceptibility profile) from catheter tip and blood cultures. We registered 4,289 patient-days and 3,572 catheter-days in the control period and 4,174 patient-days and 3,296 catheter-days in the intervention period. No significant differences in the number of patients with central venous catheters during the two periods were observed: catheters were used in 81.5% of patients during the control period and in 80.6% of patients during the intervention period. During the control period, 24 CR-BSI were diagnosed (6.7/1,000 catheter-days); during the intervention period, 8 CR-BSI were diagnosed (2.4/1,000 catheter-days) (relative risk 0.36; 95% confidence interval [CI] 0.16 to 0.80; p = 0.015). Nurses interrupted the procedure to correct at least one aspect when completing the checklist in 17.7% of insertions. In conclusion, a multiple system intervention applying evidence-based measures reduced the incidence of CR-BSI in our ICU.

Extended van Hove singularity and superconducting instability in doped graphene

We have investigated the effects of doping on a single layer of graphene using angle-resolved photoemission spectroscopy. We show that many-body interactions severely warp the Fermi surface, leading to an extended van Hove singularity (EVHS) at the graphene M point. The ground state properties of graphene with such an EVHS are calculated, analyzing the competition between a magnetic instability and the tendency towards superconductivity. We find that the latter plays the dominant role as it is enhanced by the strong modulation of the interaction along the Fermi line, leading to an energy scale for the onset of the pairing instability as large as 1 meV when the Fermi energy is sufficiently close to the EVHS.

Comparison of transient elastography and liver biopsy for the assessment of liver fibrosis in HIV/hepatitis C virus-coinfected patients and correlation with noninvasive serum markers

Transient elastography (FibroScan) is a novel, rapid and noninvasive technique to assess liver fibrosis. Our objective was to compare transient elastography (TE) and other noninvasive serum indexes as alternatives to liver biopsy in HIV/hepatitis C virus (HCV)-coinfected patients. The fibrosis stage (METAVIR Score), TE, the aspartate aminotransferase-to-platelet ratio index, the Forns fibrosis index, FIB-4 and HGM-2 indexes were assessed in 100 patients between January 2007 and January 2008. The diagnostic values were compared by calculating the area under the receiver operating characteristic curves (AUROCs). Using TE, the AUROC (95% CI) of liver stiffness was 0.80 (0.72-0.89) when discriminating between F <or= 1 and F > 2, 0.93 (0.85-1.00) when discriminating between F <or= 2 and F > 3 and 0.99 (0.97-1.00) when discriminating between F <or= 3 and F4. For the diagnosis of F >or= 3, the AUROCs of TE were significantly higher than those obtained with the other four noninvasive indexes. Based on receiver operating characteristic curves, three cutoff values were chosen to identify F <or= 1 (<7 kPa), F >or= 3 (>or=11 kPa) and F4 (>or=14 kPa). Using these best cutoff scores, the negative predictive value and positive predictive value were 81.1% and 70.2% for the diagnosis of F <or= 1, 96.3% and 60% for the diagnosis of F >or= 3 and 100% and 57.1% for the diagnosis of F4. Thus, Transient elastography accurately predicted liver fibrosis and outperformed other simple noninvasive indexes in HIV/HCV-coinfected patients. Our data suggest that TE is a helpful tool for guiding therapeutic decisions in clinical practice.

Use of simple noninvasive biomarkers to predict liver fibrosis in HIV/HCV coinfection in routine clinical practice

BACKGROUND

Simple noninvasive tests to predict fibrosis, as an alternative to liver biopsy (LB), are needed. Of these, the aspartate aminotransferase (AST) to platelet ratio index (APRI) and the Forns index (FI) have been validated in HIV/hepatitis C virus (HCV) coinfection. However, these indexes may have lower diagnostic value in situations other than the circumscribed conditions of validation studies. We therefore examined the value of the APRI and FI in HIV/HCV-coinfected patients for the detection of significant fibrosis in real-life conditions.

PATIENTS AND METHODS

HIV/HCV-coinfected patients who had participated in a multicentre cross-sectional retrospective study were selected if they had undergone an LB within 24 months before the last visit. The predictive accuracy of the APRI and FI was measured using the areas under receiver-operating-characteristic curves (AUROCs). Diagnostic accuracy was determined using the positive (PPV) and negative (NPV) predictive values.

RESULTS

A total of 519 coinfected individuals were included in the study. The AUROC [95% confidence interval (95% CI)] of the APRI was 0.67 (0.66-0.71) and that of the FI was 0.67 (0.62-0.71). The PPV of the APRI was 79% and its NPV was 66%. The PPV of the FI was 74% and its NPV was 64%. LB length was available and was > or =15 mm in 120 individuals. In this group, the PPV of the APRI was 85%, and that of the FI was 81%. Using these indexes, 22% of patients could be spared LB. Applying both models sequentially, 30% of patients could be spared LB.

CONCLUSIONS

In HIV/HCV-coinfected patients, the diagnostic accuracy of the APRI in real-life conditions was similar to that in the validation studies. The FI performed less well. However, combining the two indexes to make decisions on anti-HCV therapy may prevent a significant proportion of patients from having to undergo LB.

Left atrial remodelling in hypertrophic cardiomyopathy: relation with exercise capacity and biochemical markers of tissue strain and remodelling

BACKGROUND

Left atrial remodelling, assessed as left atrial volume (LAV), has been proposed as a good marker of left ventricular diastolic dysfunction. The aim of this study was to analyse the influence of LAV on exercise performance in hypertrophic cardiomyopathy (HCM), and in a subset of subjects, assess the relation of LAV and exercise performance to four biomarkers of disease pathophysiology: matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) (as indices of tissue remodelling), N-terminal portion of pro B-type natriuretic peptide (NT-pro-BNP) (associated with ventricular dysfunction) and C-reactive protein (CRP, an index of inflammation).

METHODS

We studied 75 consecutive HCM patients (aged 46 +/- 14 years, 56 men) where LAV was calculated assuming the ellipsoid model with two orthogonal planes. LAV was indexed to body surface area. Exercise capacity was evaluated by treadmill exercise test (symptom limited) and assessed with metabolic equivalent units (MET). Basal NT-pro-BNP and CRP levels were measured in 70 patients, whereas MMP-2 and TIMP-1 in 43 patients.

RESULTS

Enlarged LAV was observed in those patients with previous atrial fibrillation (p = 0.016). Mean LAV was greater in patients with impaired functional New York Heart Association (NYHA) class (p < 0.001). LAV correlated with age (Spearman, r: 0.28), higher maximal left ventricular wall thickness (r: 0.32) and raised E/A ratio (r: 0.37) (all p < 0.01). LAV was significantly correlated with NT-pro-BNP values (r: 0.34; p = 0.04), MMP-2 (r: 0.32; p = 0.034), CRP (r: 0.33; p = 0.005) and correlated inversely with MET units (r: -0.39; p < 0.01). In multivariate analysis, MET units were only associated with NT-pro-BNP (p = 0.002) and LAV (p = 0.010).

CONCLUSIONS

Enlarged LAV is associated with impaired functional NYHA class and inversely with treadmill exercise capacity. Enlarged LAV is also associated with NT-pro-BNP, MMP-2 and CRP, perhaps as markers of disease severity and tissue remodelling. Age, LAV and NT-pro-BNP are independent predictors of exercise performance.

Right adrenal metastases of hepatocarcinoma after liver transplantation: case report and literature review

BACKGROUND

Hepatocellular carcinoma (HCC) represents one of the most common malignancies globally, accounting for nearly one million new cases per year. Although the treatment of extrahepatic metastases from primary liver tumors is essentially palliative, a solitary metastasis from such tumors offers a possibility of cure by surgical resection. The adrenal gland is an uncommon site for metastasis from primary liver tumors.

METHODS

We report a liver transplantation case of HCC and hepatitis B virus in a 23-year-old man with an excellent postoperative result. However, because an increased alpha-fetoprotein was evident and complete radiologic and blood tests were performed, all of which were normal. Three years posttransplantation, a right adrenal mass was identified by CT. PAAF was performed as well as adrenalectomy for a solitary adrenal metastasis from hepatocellular carcinoma.

RESULTS

The patient underwent adrenalectomy for the right adrenal metastasis at 3 years following liver transplantation for HCC. He is presently alive and disease-free 24 months after adrenalectomy.

CONCLUSION

Carefully selected patients with solitary metastasis from HCC may be considered for resection.

Tuberculosis in solid organ transplant recipients at a tertiary hospital in the last 20 years in Barcelona, Spain

OBJECTIVE

Mycobacterium tuberculosis (TB) is a serious opportunistic infection in solid organ transplant recipients. The TB incidence is 20 to 74 times greater than that among the general population. Our aim was to determine the incidence as well as the clinical, radiological, and microbiological features and outcomes of TB in these patients.

MATERIALS AND METHODS

We reviewed the clinical records of subjects with posttransplant TB from January 1988 to December 2007. A definite TB case was defined by a positive culture; probable TB by a positive smear or histological finding; and disseminated TB when 2 organs were involved. We noted an early diagnosis as ones in the first year posttransplantation. Outcomes were classified following the WHO recommendation and mortality related defined by death during treatment.

RESULTS

Among 4634 recipients (2757 kidney, 1334 liver, 361 double kidney-pancreas, and 182 heart), 21 (0.45%) developed posttransplant TB: namely, 0.47%, 0.22%, 1.1%, and 0.54%, respectively. In 2 cases M. tuberculosis did not grow upon culture; the diagnosis was established by positive acid-fast bacilli on a sputum smear or by histological findings on biopsy. The mean posttransplantation time to TB diagnosis was 21 months (48% early TB). Two patients had a previous history of TB. Fever was the most common symptom (71%). Pulmonary tuberculosis represented 47.6% of cases; extrapulmonary, 28.6%; and disseminated, 23.8%. Among the cases of pulmonary TB, 60% had unilateral infiltrates and 10% cavitations on X ray. Eighteen patients completed treatment. Five patients displayed adverse events, 3 of which were liver toxicity. Four patients died, with 3 deaths related to TB.

CONCLUSIONS

The incidence of TB in this cohort was higher than that among the general population (450 cases/100,000 recipients). TB was associated with adverse effects of treatment and significant mortality.

Sensory characterization of meat from pigs vaccinated against gonadotropin releasing factor compared to meat from surgically castrated, entire male and female pigs

Boar taint is a sensory defect mainly due to androstenone and skatole. The most common method to control boar taint is surgical castration at an early age. Vaccination against gonadotropin releasing factor (also known as immunocastration) is an alternative to surgical castration to reduce androstenone content. In this experiment, loins from 24 female (FE), 24 entire male (EM), 24 vaccinated males (IM) and 23 surgically castrated males (CM) were evaluated by eight trained panellists in 24 sessions. Loins were cooked in an oven at 180°C for 10min. Furthermore loins were evaluated by consumers and its androstenone and skatole content were also chemically determined. Meat from EM had higher androstenone and skatole odour and flavour than meat from FE, IM and CM and lower sweetness odour scores. High correlations were found between androstenone and skatole levels assessed by trained panelists, chemical analysis and consumers' acceptability. Moreover meat from EM is mainly related to androstenone and skatole attributes.

[Importance of the antimicrobial spectrum and the bacterial resistances in the antibiotic choice for the treatment of pediatric patients with communitary infections]

OBJECTIVE

This study aimed to know the importance of the antimicrobial spectrum and the bacterial resistances for the antibiotic choice in the extrahospitalary pediatric area, at the same time that establish the relationship with others therapeutics parameters.

MATERIAL AND METHODS

Cross-sectional, observational study within the MUSA (Improvement of Use of Antimicrobial Agents in Primary Health Care) Project made by personal interview of 210 pediatrician doctors randomly selected with national representation. This target is included in a bigger universe (855 doctors) representative of the most doctors responsible of the antibiotic prescriptions in the extrahospitalary area (sample error of the 3.3% for a 95% confidence interval and maximum response dispersion: p=q=50). The results of the pediatric study were subjected to a comparative analysis with the results of a similar study made ten years ago and with the global results of the general study. The questionnaire used for the interview had two clearly different parts: in the first part, the questions were open with the objective to get spontaneous answers from the participants; the second part had questions with suggested answers.

RESULTS

Clinical efficacy is the most spontaneously valued issue by the Spanish pediatricians when it comes to choosing an antimicrobial agent; efficacy is followed by tolerance/safety and posology. Antimicrobial spectrum is mentioned by one out of 4-5 pediatricians that have participated in the study (21.9%), while the bacterial resistances are only mentioned by a 3.8%. In a suggested level, clinical efficacy is still the most valued parameter, being identified by 7 out of 10 interviewed with the bacterial eradication. In this case, the antimicrobial spectrum is the following parameter on significance, appearing as a synonym of "activity against specific microorganisms" in 2 out of 3 cases. In relation to his own evaluation, 3 out of 4 pediatricians say they take "a lot" of the bacterial resistances into consideration, who are mostly understood as "global rate" for 5-6 out of 10 interviewed, whether the resistance showed by the pneumococcal is what worried the most to 4 out of 10 of them. This importance given to the bacterial resistances at the second part of the study contrasts with the low consideration showed when it is compared with other parameters and the valoration is treated in a spontaneous way. In relation to a similar study realized on 1997 (Urano Proyect), we observe that clinical efficacy has replaced tolerance/safety as a parameter to bear in mind, probably as a consequence of more experience and confidence with the most important antimicrobial agents in the antibiotic prescriptions in podiatry. On the other hand, the bacterial resistances still being left out on the pediatricians spontaneous consideration, a fact that is shared with the majority of the collectives participating on the general study. The rest of the parameters stay in a similar way.

CONCLUSIONS

Is necessary to emphasize at the importance of bacterial resistances in the antimicrobials rational use on the pediatric patient. As the antimicrobial tolerance profile has been improving in the last ten years, clinical efficacy, understood as "bacterial eradication" has became the most determining parameter when choosing antimicrobial agents.

Bottlenecks, population differentiation and apparent selection at microsatellite loci in Australian Drosophila buzzatii

Species colonizing new areas disjunct from their original habitat may be subject to novel selection pressures, and exhibit adaptive genetic changes. However, if colonization occurs through a small number of founders, the genetic composition of the colonized population may differ from that of the original population simply due to genetic drift. Disentangling the effects of founder drift and selection after colonization is crucial to understanding the adaptive process. Drosophila buzzatii colonized Australia some 600-700 generations ago, and spread rapidly over a wide geographical range. Genetic variation for 15 microsatellite loci in each of nine populations in eastern Australia was used to estimate the size of the bottleneck, and to determine if any of these microsatellites marked genomic regions subject to recent selection. We estimate that on its introduction to Australia, D. buzzatii went through a moderate bottleneck (approximately 30-40 founders). Linkage disequilibrium was common, both intrachromosomal and between loci on different chromosomes. Of the 15 loci, 2 showed evidence of selection, one exhibiting local adaptation in different populations and the other balancing selection. We conclude that linkage disequilibria may be far more common in natural populations than is generally assumed, and the loci apparently affected by selection may well be marking selection in large genome regions including many loci that are not necessarily closely linked.

[A day in Spanish microbiology. Descriptive study of the activity of the clinical microbiology departments]

INTRODUCTION

The laboratory is an essential part of the work in the Clinical Microbiology Department. This study has aimed to measure the activity of these laboratories.

MATERIAL AND METHODS

A survey was self-administered on the activity occurring during one work day by each hospital in October 2007.

RESULTS

Thirty six hospitals reported 14,076 tests. Serology was the most frequently reported test (30.3%) followed by urine culture (27.8 %), blood tests (13.2 %), respiratory tract samples (8%), feces (7.1%), urethral (5.8%), skin (5.3%) and cerebrospinal fluid (2.6%). According to species, 73.2% of the isolates were bacteria (22.9 % were positive), 8.9% were virus (17% positive), fungi 8.1% (25.2% positive), and 5.5% mycobacterias (5.9% were positive) and parasite 4.5% (12.5% positive). Susceptibility test were performed by automatic methods (62.3%) followed by diffusion test (27.1%) and E-test (9.1%). A total of 5.6% of the susceptibility tests showed in vitro resistance to antibiotics. Fungi were identified in 108 isolates. Candida and Aspergillus were the most frequent genus (85.1% and 8.3%, respectively). Origins of the samples were: lower respiratory tract (32.4 %), genital tract (24.1 %), urine (10.2 %), blood (10.2 %) and skin (10.2 %). Twelve identification techniques were used, the most frequent being the morphological test (54.8%) and biochemical test (39.7%). Broken down by departments, 20.4% were sent from the ICU, 16.7% from surgery, 29.6% from medicine and 18.5% from primary care.

DISCUSSION

Although the workload of the laboratories has been measured in this work, aspects such as specimen manipulation, clinical advice and research were not considered.

Unconventional quasiparticle lifetime in graphene

We address the question of how large can the lifetime of electronic states be at low energies in graphene, below the scale of the optical phonon modes. For this purpose, we study the many-body effects at the K point of the spectrum, which induce a strong coupling between electron-hole pairs and out-of-plane phonons. We show the existence of a soft branch of hybrid states below the electron-hole continuum when graphene is close to the charge neutrality point, leading to an inverse lifetime proportional to the cube of the quasiparticle energy. This implies that a crossover should be observed in transport properties, from such a slow decay rate to the lower bound given at very low energies by the decay into acoustic phonons.