The effect of age on the acquisition and selection of cancer driver mutations in sun-exposed normal skin.

BACKGROUND: The accumulation of somatic mutations contributes to ageing and cancer. Sunlight is the principal aetiological factor associated with skin cancer development. However, genetic and phenotypic factors also contribute to skin cancer risk. This study aimed at exploring the role of photoaging, as well as other well-known epidemiological risk factors, in the accumulation of somatic mutations in cancer-free human epidermis. MATERIAL AND METHODS: We deeply sequenced 46 genes in normal skin biopsies from 123 healthy donors, from which phenotypic data (including age, pigmentation-related genotype and phenotype) and sun exposure habits were collected. We determined the somatic mutational burden, mutational signatures, clonal selection and frequency of driver mutations in all samples. RESULTS: Our results reveal an exponential accumulation of UV-related somatic mutations with age, matching skin cancer incidence. The increase of mutational burden is in turn modified by an individual's skin phototype. Somatic mutations preferentially accumulated in cutaneous squamous cell carcinoma cancer genes and clonally expanded with age, with distinct mutational processes underpinning different age groups. Our results suggest a loss of fidelity in transcription-coupled repair later in life. CONCLUSION: Our findings reveal that ageing is not only associated with an exponential increase in the number of somatic mutations accumulated in normal epidermis, but also with selection and expansion of cancer-associated mutations. Aged, sun-exposed normal skin is thus an extended mosaic of multiple clones with driver mutations, poised for the acquisition of transforming events.

Psychophysiological Correlates of Emotional- and Alcohol-Related Cues Processing in Offspring of Alcohol-Dependent Patients.

AIMS: To determinate if offspring of alcohol-dependent patients (OA) process affective stimuli and alcohol-related cues in a different manner than control subjects do. METHODS: Event-related potentials (early posterior negativity [EPN]/ late positive potential [LPP]) and event-related oscillations (Theta) were obtained by electroencephalographic (EEG) recording during the viewing of International Affective Picture System (IAPS) images with positive, negative and neutral valence, as well as alcohol-related cues. The total sample was comprised of 60 participants, divided into two groups: one group consisted of OA (30) and the control group of participants with negative family history of alcohol use disorders (30). RESULTS: Theta power analysis implies a significant interaction between condition, region and group factors. Post-hoc analysis indicates an increased theta power for the OA at different regions, during pleasant (frontal, central, parietal, occipital, right temporal); unpleasant (frontal, central, occipital); alcohol (frontal, central, parietal, occipital, right and left temporal) and neutral (occipital) cues. There are no group differences regarding any of the event-related potential measurements (EPN/LPP). CONCLUSIONS: There is evidence of alterations in the processing of affective stimuli and alcohol-related information, evidenced by changes in theta brain oscillations. These alterations are characterized by an increased emotional reactivity, evidenced by increased theta at posterior sites. There is also an increased recruitment of emotion control, which could be a compensation mechanism, evidenced by increased theta power at anterior sites during affective stimuli and alcohol cues.

P3 Component as a Potential Endophenotype for Control Inhibition in Offspring of Alcoholics.

AIMS: To assess inhibitory processes and the ongoing event-related potential (ERP) activity of offspring of alcoholics (OA) during a Go/No-Go task, with the purpose of characterizing possible psychophysiological endophenotypes for alcohol-dependent vulnerability. SHORT SUMMARY: EEG recordings and ERP measurements of young adults with positive and negative family history of alcoholism where obtained while they performed a Go/No-Go task to assess inhibitory processes. Offspring of alcoholics showed a different ERP pattern compared to the control group and exerted greater effort than the control group. METHODS: ERP measurements were obtained by electroencephalogram (EEG) recordings of 65 participants divided into two groups: one group of 30 subjects with positive family history of alcoholism and a control group of 35 subjects with negative family history of alcoholism. They performed a Go/No-Go task, where each individual was required to classify visual stimuli by colour (Go) and inhibit their response to a No-Go signal. RESULTS: OA have higher P3 amplitudes during the Go condition in all of the regions analysed and higher No-Go P3 amplitudes than control subjects in the frontal region. Unlike controls, OA have no differences between the P3 amplitudes across conditions. CONCLUSIONS: The absence of differences between the P3 Go and No-Go observed in the OA group can be interpreted as a possible alteration related with inhibition, in a way that they may need to recruit similar resources for inhibitory and classificational processes for both conditions. Therefore, the P3 component may be considered as a useful endophenotype and a vulnerability marker to develop addictive behaviour.

A large outbreak of acute gastroenteritis in Shippensburg, Pennsylvania, 1972 revisited: evidence for common source exposure to a recombinant GII.Pg/GII.3 norovirus.

Historical outbreaks can be an important source of information in the understanding of norovirus evolution and epidemiology. Here, we revisit an outbreak of undiagnosed gastroenteritis that occurred in Shippensburg, Pennsylvania in 1972. Nearly 5000 people fell ill over the course of 10 days. Symptoms included diarrhea, vomiting, stomach cramps, and fever, lasting for a median of 24 h. Using current techniques, including next-generation sequencing of full-length viral genomic amplicons, we identified an unusual norovirus recombinant (GII.Pg/GII.3) in nine of 15 available stool samples from the outbreak. This particular recombinant virus has not been reported in recent decades, although GII.3 and GII.Pg genotypes have been detected individually in current epidemic strains. The consensus nucleotide sequences were nearly identical among the four viral genomes analysed, although each strain had three to seven positions in the genome with heterogenous non-synonymous nucleotide subpopulations. Two of these resulting amino acid polymorphisms were conserved in frequency among all four cases, consistent with common source exposure and successful transmission of a mixed viral population. Continued investigation of variant nucleotide populations and recombination events among ancestral norovirus strains such as the Shippensburg virus may provide unique insight into the origin of contemporary strains.

[Patients treated with micafungin during their stay in intensive care unit]. / Micafungina en pacientes críticos ingresados en unidad de cuidados intensivos.

OBJECTIVES: To determine the reasons of prescription, the characteristics of patients and factors that affected the outcome of critically ill patients treated with micafungin (MCF) during their stay in Spanish ICUs. MATERIAL AND METHODS: Observational, retrospective and multicenter study. Patients admitted to the ICU between March 2011 and October 2012 (20-month period) treated with MCF for any reason were included in the study. Severity of patients at the beginning of treatment was measured with the APACHE II, SOFA, Child-Pugh and MELD scores. Reasons for the use of MCF were classified as prophylaxis, preemptive treatment, empirical treatment and directed treatment. Continuous variables are expressed as mean and standard deviation or median, and categorical variables as percentages. A multivariate analysis was performed to identify variables related to intra-ICU mortality. RESULTS: The study population included 139 patients admitted to 19 Spanish ICUs, with a mean age of 57.3 (17.1) years, 89 (64%) men, with surgical (53.2%) and/or medical (44.6%) conditions, APACHE II score of 20.6 (7.7) and SOFA score of 8.4 (4.3), with 84.2% of patients requiring mechanical ventilation, 59% parenteral nutrition, 37.4% extrarenal depuration procedures and 37.4% treatment with steroids. MCF was indicated as empirical treatment of a proven infection in 51 (36.7%) cases, pre-emptive treatment in 50 (36%) especially as a result of the application of the Candida score (32 cases), directed treatment of fungal infection in 23 (16.5%) and as prophylactic treatment in 15 (10.8%) cases. In 108 (77%) cases, a daily dose of 100mg was administered, with a loading dose in only 9 cases (6.5%). The mean duration of treatment was 13.1 (13) days. A total of 59 (42.4%) patients died during their stay in the ICU and 16 after ICU discharge (hospital mortality 53.9%). Independent risk factors for intra-ICU mortality were the Child-Pugh score (OR 1.45, 95% CI 1.162-1.813; P=.001) and the MELD score (OR 1.05, 95% CI 1.011-1.099; P=.014). CONCLUSIONS: MCF is usually administered at a dose of 100mg/day, without loading dose and in 72.7% of cases as pre-emptive or empirical treatment. Factors that better predicted mortality were indicators of liver insufficiency at the time of starting treatment.

Viral load of human bocavirus-1 in stools from children with viral diarrhoea in Paraguay.

Since their discovery, four species of human bocavirus (HBoV) have been described in patients with respiratory and gastrointestinal diseases. However, a clear causal association between HBoV-1 and gastroenteritis has not been demonstrated. In this study, we describe the detection and quantification of HBoV-1 in stools from children with acute non-bacterial gastroenteritis using quantitative polymerase chain reaction. HBoV-1 genome was detected in 10.6% of stools with frequent association with rotavirus and norovirus. The median of HBoV-1 viral load was 1.88 × 104 genome/ml, lower than previously shown in secretions of patients with respiratory infections, without any obvious association between high viral load and presence of HBoV as single agent. Thus, although HBoV-1 was frequently detected in these patients, there is no clear causal association of this agent with diarrhoea. Indeed, HBoV-1 DNA in stools of patients with gastroenteritis without respiratory symptoms may be a remnant of previous infections or associated with prolonged shedding of virus in the respiratory or digestive tracts.

Added value of umbilical vein flow as a predictor of perinatal outcome in term small-for-gestational-age fetuses.

OBJECTIVE: To compare umbilical vein (UV) flow with standard Doppler parameters in prediction of adverse perinatal outcome in late-onset small-for-gestational age (SGA) fetuses. METHODS: Umbilical, uterine and middle cerebral arteries, and UV blood flow were evaluated by Doppler before delivery in a cohort of 193 term SGA fetuses. The value of the Doppler parameters to predict risk of emergency delivery for non-reassuring fetal status and neonatal metabolic acidosis was analyzed. RESULTS: Fifty-three (27%) fetuses had non-reassuring fetal status requiring emergency delivery, whereas 21 (11%) newborns developed neonatal metabolic acidosis. Multivariable analysis showed that significant contributions to prediction of emergency delivery for non-reassuring fetal status and neonatal metabolic acidosis were provided by middle cerebral artery (MCA) pulsatility index (PI) and UV blood flow normalized by fetal weight. Decision tree analysis defined three groups with increasing risk of need for emergency delivery for non-reassuring fetal status: MCA-PI > 1.46 (risk 15.6%); MCA-PI ≤ 1.46 and UV blood flow > 68 mL/min/kg (risk 25%); and MCA-PI ≤ 1.46 and UV flow ≤ 68 mL/min/kg (risk 53.1%); and two groups with different risks of neonatal metabolic acidosis: UV flow > 68 mL/min/kg or UV flow ≤ 68 mL/min/kg and MCA-PI > 1.23 (risk ≤ 10%); and UV flow ≤ 68 mL/min/kg and MCA-PI ≤ 1.23 (risk 39.1%). CONCLUSION: The evaluation of UV blood flow with spectral brain Doppler allows better identification of SGA fetuses with late-onset intrauterine growth restriction at risk of adverse perinatal outcome.

Comparative and functional analysis of intron-mediated enhancement signals reveals conserved features among plants.

Introns in a wide range of organisms including plants, animals and fungi are able to increase the expression of the gene that they are contained in. This process of intron-mediated enhancement (IME) is most thoroughly studied in Arabidopsis thaliana, where it has been shown that enhancing introns are typically located near the promoter and are compositionally distinct from downstream introns. In this study, we perform a comprehensive comparative analysis of several sequenced plant genomes. We find that enhancing sequences are conserved in the multi-cellular plants but are either absent or unrecognizable in algae. IME signals are preferentially located towards the 5'-end of first introns but also appear to be enriched in 5'-UTRs and coding regions near the transcription start site. Enhancing introns are found most prominently in genes that are highly expressed in a wide range of tissues. Through site-directed mutagenesis in A. thaliana, we show that IME signals can be inserted or removed from introns to increase or decrease gene expression. Although we do not yet know the specific mechanism of IME, the predicted signals appear to be both functional and highly conserved.

Neonatal mice genetically modified to express the elastase inhibitor elafin are protected against the adverse effects of mechanical ventilation on lung growth.

Mechanical ventilation (MV) with O(2)-rich gas (MV-O(2)) offers life-saving treatment for newborn infants with respiratory failure, but it also can promote lung injury, which in neonates translates to defective alveolar formation and disordered lung elastin, a key determinant of lung growth and repair. Prior studies in preterm sheep and neonatal mice showed that MV-O(2) stimulated lung elastase activity, causing degradation and remodeling of matrix elastin. These changes yielded an inflammatory response, with TGF-ß activation, scattered elastic fibers, and increased apoptosis, culminating in defective alveolar septation and arrested lung growth. To see whether sustained inhibition of elastase activity would prevent these adverse pulmonary effects of MV-O(2), we did studies comparing wild-type (WT) and mutant neonatal mice genetically modified to express in their vascular endothelium the human serine elastase inhibitor elafin (Eexp). Five-day-old WT and Eexp mice received MV with 40% O(2) (MV-O(2)) for 24-36 h. WT and Eexp controls breathed 40% O(2) without MV. MV-O(2) increased lung elastase and MMP-9 activity, resulting in elastin degradation (urine desmosine doubled), TGF-ß activation (pSmad-2 increased 6-fold), apoptosis (cleaved-caspase-3 increased 10-fold), and inflammation (NF-κB activation, influx of neutrophils and monocytes) in lungs of WT vs. unventilated controls. These changes were blocked or blunted during MV-O(2) of Eexp mice. Scattered lung elastin and emphysematous alveoli observed in WT mice after 36 h of MV-O(2) were attenuated in Eexp mice. Both WT and Eexp mice showed defective VEGF signaling (decreased lung VEGF-R2 protein) and loss of pulmonary microvessels after lengthy MV-O(2), suggesting that elafin's beneficial effects during MV-O(2) derived primarily from preserving matrix elastin and suppressing lung inflammation, thereby enabling alveolar formation during MV-O(2). These results suggest that degradation and remodeling of lung elastin can contribute to defective lung growth in response to MV-O(2) and might be targeted therapeutically to prevent ventilator-induced neonatal lung injury.

The training-induced changes on automatism, conduction and myocardial refractoriness are not mediated by parasympathetic postganglionic neurons activity.

The purpose of this study is to test the role that parasympathetic postganglionic neurons could play on the adaptive electrophysiological changes produced by physical training on intrinsic myocardial automatism, conduction and refractoriness. Trained rabbits were submitted to a physical training protocol on treadmill during 6 weeks. The electrophysiological study was performed in an isolated heart preparation. The investigated myocardial properties were: (a) sinus automatism, (b) atrioventricular and ventriculoatrial conduction, (c) atrial, conduction system and ventricular refractoriness. The parameters to study the refractoriness were obtained by means of extrastimulus test at four different pacing cycle lengths (10% shorter than spontaneous sinus cycle length, 250, 200 and 150 ms) and (d) mean dominant frequency (DF) of the induced ventricular fibrillation (VF), using a spectral method. The electrophysiological protocol was performed before and during continuous atropine administration (1 µM), in order to block cholinergic receptors. Cholinergic receptor blockade did not modify either the increase in sinus cycle length, atrioventricular conduction and refractoriness (left ventricular and atrioventricular conduction system functional refractory periods) or the decrease of DF of VF. These findings reveal that the myocardial electrophysiological modifications produced by physical training are not mediated by intrinsic cardiac parasympathetic activity.

Prediction of preterm birth using the cervical consistency index.

OBJECTIVES: To assess the diagnostic power of a new cervical consistency index (CCI) obtained using transvaginal sonography for the prediction of spontaneous preterm birth (PTB) and to establish reference ranges for this new variable. METHODS: Included in this prospective cross-sectional study were 1115 singleton pregnancies at 5-36 weeks of gestation. Anteroposterior cervical diameter was measured before (AP) and after (AP') application of pressure on the cervix using the transvaginal probe. The index was calculated using the formula: CCI=((AP'/AP) × 100). Cervical length was also measured. The outcomes evaluated were spontaneous PTB before 32, 34 and 37 weeks. Logistic regression and analysis of receiver-operating characteristics (ROC) curves were performed to evaluate the diagnostic power of CCI and cervical length (adjusted for gestational age). Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to evaluate intra- and interobserver variability. RESULTS: In the 1031 women with follow-up, the rate of spontaneous PTB before 32 weeks was 0.87%, before 34 weeks was 2.13% and before 37 weeks was 7.76% (n=80). There were 31 (3.01%) iatrogenic PTBs before 37 weeks. An inverse linear correlation between gestational age and CCI was observed, with regression equation: CCI (in %)=89.8 - 1.35 × (GA in weeks); r(2)=0.66, P<0.001. Cervical length showed an inverse quadratic, though non-significant, relationship with gestational age: CL (in mm)=31.084 - 0.0278× (GA in weeks)(2) + 1.0772× (GA in weeks); r(2)=0.076, P<0.14. The intra- and interobserver ICCs for CCI were 0.99 (95% CI, 0.988-0.994) and 0.98 (95% CI, 0.973-0.987), respectively. The area under the ROC curve for CCI in the prediction of spontaneous PTB before 32 weeks was 0.947, for spontaneous PTB before 34 weeks it was 0.943 and for spontaneous PTB before 37 weeks it was 0.907. For a 5% screen-positive rate, CCI had a sensitivity of 67%, 64% and 45% for prediction of spontaneous PTB before 32, 34 and 37 weeks, respectively, with equivalent values of 11%, 9% and 11% for cervical length. CONCLUSIONS: CCI shows a clear inverse linear relationship with GA. Assessment of CCI is reproducible and is effective in the prediction of spontaneous PTB. This new variable appears to provide better prediction of spontaneous PTB than does cervical length.

Experimental and theoretical study of two-photon absorption in nitrofuran derivatives: Promising compounds for photochemotherapy.

We report experimental and theoretical studies of the two-photon absorption spectrum of two nitrofuran derivatives: nitrofurantoine, (1-(5-nitro-2-furfurilideneamine)-hidantoine) and quinifuryl, 2-(5(')-nitro-2(')-furanyl)ethenyl-4-{N-[4(')-(N,N-diethylamino)-1(')-methylbutyl]carbamoyl} quinoline. Both molecules are representative of a family of 5-nitrofuran-ethenyl-quinoline drugs that have been demonstrated to display high toxicity to various species of transformed cells in the dark. We determine the two-photon absorption cross-section for both compounds, from 560 to 880 nm, which present peak values of 64 GM for quinifuryl and 20 GM for nitrofurantoine (1 GM = 1×10(-50)cm(4).s.photon(-1)). Besides, theoretical calculations employing the linear and quadratic response functions were carried out at the density functional theory level to aid the interpretations of the experimental results. The theoretical results yielded oscillator strengths, two-photon transition probabilities, and transition energies, which are in good agreement with the experimental data. A higher number of allowed electronic transitions was identified for quinifuryl in comparison to nitrofurantoine by the theoretical calculations. Due to the planar structure of both compounds, the differences in the two-photon absorption cross-section values are a consequence of their distinct conjugation lengths.

Beaming in the Charcot foot: A case series with 12-month minimum follow-up.

BACKGROUND: Charcot neuropathic arthropathy is a progressive degeneration of the weightbearing joints of the foot induced by denervation and disturbance of sensorial perception. This entity clinically behaves as a destructive fast-progressive arthropathy, resulting in loss of independent walking and often requiring amputation of the leg. This study analyzes our experience with midfoot realignment arthrodesis and stabilization by intramedullary beaming in patients with Charcot diabetic foot as a limb-sparing procedure. METHODS: Patients with Charcot foot treated in our Foot and Ankle unit between January 2018 and December 2019 were analyzed. In all of the patients beaming technique was performed: open reduction and stabilization by a midfoot medial fusion beam and a lateral fusion bolt. Demographical, clinical and radiological pre and post-surgery data were assessed. The primary outcome measure was defined as an autonomous ambulation through an ulcer-free plantigrade foot. A minimum follow-up of 12 months was performed. RESULTS: A total of 5 patients were treated. Median age 64 years, mean follow-up 25 months (12-31). An ulcer-free plantigrade foot was obtained in 80% of the patients. Complications were observed in 80% of patients: 1 deep infection, 2 hardware failure, 3 Charcot foot progression. Rate of reoperation 40%, including 1 amputation. Significant improvement in all radiographic angles was observed. CONCLUSION: Beaming the medial and lateral columns of the foot in patients with Charcot foot enabled the restoration of a functional plantigrade foot and an ulcer-free autonomous ambulation, despite a relatively high complication rate. LEVEL OF EVIDENCE: IV, prospective case series.

Chilean validation of the operationalized psychodynamic diagnosis-structure questionnaire (OPD-SQ) for personality structure.

BACKGROUND: This is the validation of the Operationalized Psychodynamic Diagnosis-Structure Questionnaire (OPD-SQ). METHODS: A clinical sample of 399 adults and a nonclinical general population sample of 50 healthy adults completed measures of depression, attachment, psychiatric symptomatology and distress. Internal consistency and concurrent validity were assessed. Test-retest and Reliable Change Index were also calculated, as was the ability of the OPD-SQ to distinguish between the clinical and general population groups. RESULTS: High internal consistencies were found; significant differences between clinical and nonclinical samples, and significant associations with psychiatric symptomatology, depression and psychological distress. CONCLUSION: The Chilean OPD-SQ has good reliability, and discriminates between clinical and healthy samples.

Intraspecific and interspecific tolerance to copper sulphate in five Iberian amphibian species at two developmental stages.

Intraspecific and interspecific variations have been observed across many taxa with respect to resistance to natural environmental stressors. It has already been well documented that amphibians are sensitive to habitat degradation and are regarded as bioindicators of aquatic and agricultural ecosystems. In southern Spain, different toxic substances, including copper sulphate, which is used to control Cycloconium oleaginum (Fungi, Ascomycota, Venturiaceae) during spring and autumn, are used in intensive olive tree agriculture. In this context, many wetlands are affected by a diffuse pollution process. Thus, toxicological studies using different species living in wetlands surrounded by agricultural activity are needed to understand the alterations suffered by these ecosystems. To achieve this understanding, individuals of five amphibian species (Bufo bufo, Epidalea calamita, Discoglossus jeanneae, Pelobates cultripes, and Pelophylax perezi) at Gosner developmental stages 19 and 25 were exposed to different copper sulphate concentrations in 96 h acute toxicity tests. Exposure to copper sulphate had a negative effect on total larval length reached at the end of the experimental period and generated approximately 30% of growth reduction respect to control treatments. P. perezi was the most tolerant species studied and showed no mortality at the maximum concentration tested (0.20 mg Cu L(-1)), whereas the most sensitive species (B. bufo, E. calamita, and D. jeanneae) showed approximately 90% mortality at the same concentration. These results indicates that the sole presence in wetlands of P. perezi, the most abundant species in southeast of Iberian Peninsula, might be correlated with its high tolerance to agrochemicals.

[Molecular and histological detection of Helicobacter pylori and genotyping based on babA2 and iceA in patients with benign gastric pathologies]. / Detección histológica y molecular de Helicobacter pylori y genotipificación con base en los genes de virulencia babA2 e iceA en pacientes con patología gástrica benigna.

OBJECTIVE: To investigate the presence of Helicobacter pylori in a Colombian population. MATERIAL AND METHODS: Gastric biopsies from 60 patients with benign gastric pathologies were submitted to histopathological examination and genotyped by PCR through amplification of babA2 and iceA genes. RESULTS: The presence of H. pylori was demonstrated in 78.3%, 63.3% and 66.7% of the samples after Giemsa staining, andH. pylori 16S DNAr and iceA gene amplification, respectively. In addition, H. pylori babA2 positive was found infecting 7 patients. Among the iceA positive samples, 35% were identified as iceAl, 47.5% as iceA2 and 17.5% contained iceAl and iceA2 or different iceA2 types. This work allowed detection and genotyping of H. pylori, demonstrating a low proportion of patients carrying strains babA2 positive and an iceA genotype distribution according to previous reports. No association was found between the presence of babA2 and iceA genes and ulcer disease.

Effects of copper sulfate on growth, development, and escape behavior in Epidalea calamita embryos and larvae.

Epidalea calamita embryos at Gosner stages 3 and 19, and larvae at Gosner stage 25, were exposed to different copper sulfate concentrations, ranging from 0.05 to 0.40 mg Cu L(-1), in 96-h acute toxicity tests. Embryonic and larval mortality, development, growth, and larval escape behavior were evaluated. LC(50) at 96 h obtained at Gosner stages 3, 19, and 25 were 0.22, 0.08, and 0.11 mg Cu L(-1), respectively. Embryonic and larval developments were delayed after 96 h of copper sulfate exposure. Growth was also affected and individuals in control treatments grew to twice the size of those exposed to copper concentrations over 0.2 mg Cu L(-1) during the experiments initiated at Gosner stage 19. Escape behavior was altered after 96 h of copper sulfate exposure; larvae showed shorter distances moved and abnormal displacement types. However, after 4 days of recovery process, most of the larvae showed normal escape behavior. For amphibians that develop in temporary wetlands, increased development time, lower size, and altered escape behavior might have repercussions on the number of individuals that can successfully complete metamorphosis and, consequently, on recruitment.

[Characterization of the Helicobacter pylori vacuolating cytotoxin gene in gastric biopsy specimens from patients living in Tolima, Colombia]. / Caracterización del gen de la citotoxina vacuolizante de Helicobacter pylori a partir de biopsias gástricas de pacientes residentes en Tolima, Colombia.

Helicobacter pylori successfully colonizes the gastric niche. These bacteria produce a vacuolating cytotoxin known as VacA, which is codified by the vacA gene. This protein represents an important virulence factor. H. pylori strains have different vacA alleles, which show a variety of phenotypes that have been associated with gastrointestinal diseases. The aim of this study was to generate data about the prevalence of H. pylori and the vacA genotype in Tolima (Colombia) residents, and to evaluate if there exists a relationship between these data and the development of different gastrointestinal pathologies. Seventy three patients with different pathologies were included. The DNA extracted from biopsy specimens was analyzed and the presence of bacteria was determined by amplifying a fragment of the 16 rDNA gene. The vacA genotype was also determined by PCR. Fifty-two percent out of the 50 genotyped samples showed vacA s1m1 allele, 42% vacA s2m2, 4% s1m2, and 2% s1,s2,m1,m2. A higher sensitivity for the detection of H. pylori was evidenced by amplifying the vacA gene rather than the 16S rDNA gene. No association was found between the vacA genotype and the gastrointestinal diseases included in the study.

Intraspecific variation in the response of the estuarine European isopod Cyathura carinata (Krøyer, 1847) to ocean acidification.

In the present study the model isopod, Cyathura carinata were exposed to four pHNIST treatments (control: 7.9; 7.5, 7, 6.5) in order to determine the tolerance and pH threshold value this estuarine species withstand under future acidification scenarios. Seawater acidification significantly affected the lifespan of C. carinata, where population density was remarkably reduced at the lowest pH treatment. The longevity, survivorship and swimming activity (related to the acquisition of energy) of these isopods decreased with decreasing pH. Furthermore, to determine the possible metabolic plasticity of this species, the swimming activity, the Na+/K + -ATPase activity (relevant for osmoregulation process), and the RNA:DNA ratio (an indicator of fitness) were measure from two populations of C. carinata, one inhabiting a stable environment (pHNIST 7.5-8.0) and one inhabiting a fluctuating pCO2 regimes (pH 3.3-8.5) subjected to three pH treatments (7.9, 7.0 and 6.5). The population from high fluctuating pCO2 conditions showed capacity to withstand to pH 6.5, as well as higher longevity and metabolic plasticity, when compared with the population from the habitat with slight pCO2 variation. These results indicate that Cyathura population from stable environments could be vulnerable to ocean acidification because it could trigger detrimental effects on its survival energy budget, and growth. However, ocean acidification has limited effect on the energy budget and survival of C. carinata population from highly variable habitats, suggesting that they are able to cope with the elevated energy demand. The difference showed between populations is likely an indication of genetic differentiation in tolerance to ocean acidification, possibly attributable to local adaptations, which could provide the raw material necessary for adaptation to future conditions. In addition, our results suggest that when assessing marine crustacean responses to changing environments on a global scale, variability in population and metabolic responses need to be considered.

CO2 leakage simulation: Effects of the decreasing pH to the survival and reproduction of two crustacean species.

The effects of CO2-related acidification on two crustacean populations, the isopod Cyathura carinata and the amphipod Elasmopus rapax, were studied. Three pH levels were tested: artificial seawater without CO2 injection and two levels of reduced pH. Even though RNA:DNA ratio was reduced for both species, no statistical significant differences were found between the control and the treatments. Both species experienced a reduction in survivorship, longevity and the body length of surviving animals; although the impairment observed in E. rapax was more severe than in C. carinata. The long life span isopod and the short life span amphipod experienced a high degree of impairment in the reproduction, likely due to the reallocation of resources from reproduction to body maintenance and increasing survival by postponing the brood production. Regardless of the underlying processes and the energetic pathways, both experienced failure to reproduce, which could lead to the local extinction of these species.