Heterogeneity of SOS response expression in clinical isolates of Escherichia coli influences adaptation to antimicrobial stress.

In recent years, new evidence has shown that the SOS response plays an important role in the response to antimicrobials, with involvement in the generation of clinical resistance. Here we evaluate the impact of heterogeneous expression of the SOS response in clinical isolates of Escherichia coli on response to the fluoroquinolone, ciprofloxacin. In silico analysis of whole genome sequencing data showed remarkable sequence conservation of the SOS response regulators, RecA and LexA. Despite the genetic homogeneity, our results revealed a marked differential heterogeneity in SOS response activation, both at population and single-cell level, among clinical isolates of E. coli in the presence of subinhibitory concentrations of ciprofloxacin. Four main stages of SOS response activation were identified and correlated with cell filamentation. Interestingly, there was a correlation between clinical isolates with higher expression of the SOS response and further progression to resistance. This heterogeneity in response to DNA damage repair (mediated by the SOS response) and induced by antimicrobial agents could be a new factor with implications for bacterial evolution and survival contributing to the generation of antimicrobial resistance.

The mef(A)/msr(D)-carrying streptococcal prophage Φ1207.3 encodes an SOS-like system, induced by UV-C light, responsible for increased survival and increased mutation rate.

Bacterial SOS response is an inducible system of DNA repair and mutagenesis. Streptococci lack a canonical SOS response, but an SOS-like response was reported in some species. The mef(A)-msr(D)-carrying prophage Ф1207.3 of Streptococcus pyogenes contains a region, spanning orf6 to orf11, showing homology to characterized streptococcal SOS-like cassettes. Genome-wide homology search showed the presence of the whole Φ1207.3 SOS-like cassette in three S. pyogenes prophages, while parts of it were found in other bacterial species. To investigate whether this cassette confers an SOS-mutagenesis phenotype, we constructed Streptococcus pneumoniae R6 isogenic derivative strains: (i) FR172, streptomycin resistant, (ii) FR173, carrying Φ1207.3, and (iii) FR174, carrying a recombinant Φ1207.3, where the SOS-like cassette was deleted. These strains were used in survival and mutation rate assays using a UV-C LED instrument, for which we designed and 3D-printed a customized equipment, constituted of an instrument support and swappable-autoclavable mini-plates and lids. Upon exposure to UV fluences ranging from 0 to 6,400 J/m2 at four different wavelengths, 255, 265, 275, and 285 nm, we found that the presence of Φ1207.3 SOS-like cassette increases bacterial survival up to 34-fold. Mutation rate was determined by measuring rifampicin resistance acquisition upon exposure to UV fluence of 50 J/m2 at the four wavelengths by fluctuation test. The presence of Φ1207.3 SOS-like cassette resulted in a significant increase in the mutation rate (up to 18-fold) at every wavelength. In conclusion, we demonstrated that Φ1207.3 carries a functional SOS-like cassette responsible for an increased survival and increased mutation rate in S. pneumoniae. IMPORTANCE Bacterial mutation rate is generally low, but stress conditions and DNA damage can induce stress response systems, which allow for improved survival and continuous replication. The SOS response is a DNA repair mechanism activated by some bacteria in response to stressful conditions, which leads to a temporary hypermutable phenotype and is usually absent in streptococcal genomes. Here, using a reproducible and controlled UV irradiation system, we demonstrated that the SOS-like gene cassette of prophage Φ1207.3 is functional, responsible for a temporary hypermutable phenotype, and enhances bacterial survival to UV irradiation. Prophage Φ1207.3 also carries erythromycin resistance genes and can lysogenize different pathogenic bacteria, constituting an example of a mobile genetic element which can confer multiple phenotypes to its host.

Factors for success of awake prone positioning in patients with COVID-19-induced acute hypoxemic respiratory failure: analysis of a randomized controlled trial.

BACKGROUND: Awake prone positioning (APP) improves oxygenation in coronavirus disease (COVID-19) patients and, when successful, may decrease the risk of intubation. However, factors associated with APP success remain unknown. In this secondary analysis, we aimed to assess whether APP can reduce intubation rate in patients with COVID-19 and to focus on the factors associated with success. METHODS: In this multicenter randomized controlled trial, conducted in three high-acuity units, we randomly assigned patients with COVID-19-induced acute hypoxemic respiratory failure (AHRF) requiring high-flow nasal cannula (HFNC) oxygen to APP or standard care. Primary outcome was intubation rate at 28 days. Multivariate analyses were performed to identify the predictors associated to treatment success (survival without intubation). RESULTS: Among 430 patients randomized, 216 were assigned to APP and 214 to standard care. The APP group had a lower intubation rate (30% vs 43%, relative risk [RR] 0.70; CI95 0.54-0.90, P = 0.006) and shorter hospital length of stay (11 interquartile range [IQR, 9-14] vs 13 [IQR, 10-17] days, P = 0.001). A respiratory rate ≤ 25 bpm at enrollment, an increase in ROX index > 1.25 after first APP session, APP duration > 8 h/day, and a decrease in lung ultrasound score ≥ 2 within the first 3 days were significantly associated with treatment success for APP. CONCLUSION: In patients with COVID-19-induced AHRF treated by HFNC, APP reduced intubation rate and improved treatment success. A longer APP duration is associated with APP success, while the increase in ROX index and decrease in lung ultrasound score after APP can also help identify patients most likely to benefit. TRIAL REGISTRATION: This study was retrospectively registered in ClinicalTrials.gov at July 20, 2021. Identification number NCT04477655. https://clinicaltrials.gov/ct2/show/NCT04477655?term=PRO-CARF&draw=2&rank=1.

Lung ultrasound response to awake prone positioning predicts the need for intubation in patients with COVID-19 induced acute hypoxemic respiratory failure: an observational study.

BACKGROUND: Awake prone positioning (APP) reduces the intubation rate in COVID-19 patients treated by high-flow nasal cannula (HFNC). However, the lung aeration response to APP has not been addressed. We aimed to explore the lung aeration response to APP by lung ultrasound (LUS). METHODS: This two-center, prospective, observational study enrolled patients with COVID-19-induced acute hypoxemic respiratory failure treated by HFNC and APP. LUS score was recorded 5-10 min before, 1 h after APP, and 5-10 min after supine in the first APP session within the first three days. The primary outcome was LUS score changes in the first three days. Secondary outcomes included changes in SpO2/FiO2 ratio, respiratory rate and ROX index (SpO2/FiO2/respiratory rate) related to APP, and the rate of treatment success (patients who avoided intubation). RESULTS: Seventy-one patients were enrolled. LUS score decreased from 20 (interquartile range [IQR] 19-24) to 19 (18-21) (p < 0.001) after the first APP session, and to 19 (18-21) (p < 0.001) after three days. Compared to patients with treatment failure (n = 20, 28%), LUS score reduction after the first three days in patients with treatment success (n = 51) was greater (- 2.6 [95% confidence intervals - 3.1 to - 2.0] vs 0 [- 1.2 to 1.2], p = 0.001). A decrease in dorsal LUS score > 1 after the first APP session was associated with decreased risk for intubation (Relative risk 0.25 [0.09-0.69]). APP daily duration was correlated with LUS score reduction in patients with treatment success, especially in dorsal lung zones (r = - 0.76; p < 0.001). CONCLUSIONS: In patients with acute hypoxemic respiratory failure due to COVID-19 and treated by HFNC, APP reduced LUS score. The reduction in dorsal LUS scores after APP was associated with treatment success. The longer duration on APP was correlated with greater lung aeration. Trial registration This study was prospectively registered on clinicaltrials.gov on April 22, 2021. Identification number NCT04855162 .

A psycho-educational intervention programme for parents with SGA foetuses supported by an adaptive mHealth system: design, proof of concept and usability assessment.

BACKGROUND: Technology-based approaches during pregnancy can facilitate the self-reporting of emotional health issues and improve well-being. There is evidence to suggest that stress during pregnancy can affect the foetus and result in restricted growth and preterm birth. Although a number of mobile health (mHealth) approaches are designed to monitor pregnancy and provide information about a specific aspect, no proposal specifically addresses the interventions in parents at risk of having small-for-gestational-age (SGA) or premature babies. Very few studies, however, follow any design and usability guidelines which aim to ensure end-user satisfaction when using these systems. RESULTS: We have developed an interactive, adaptable mHealth system to support a psycho-educational intervention programme for parents with SGA foetuses. The relevant results include a metamodel to support the task of modelling current or new intervention programmes, an mHealth system model with runtime adaptation to changes in the programme, the design of a usable app (called VivEmbarazo) and an architectural design and prototype implementation. The developed mHealth system has also enabled us to conduct a proof of concept based on the use of the mHealth systems and this includes data analysis and assesses usability and acceptance. CONCLUSIONS: The proof of concept confirms that parents are satisfied and that they are enthusiastic about the mHealth-supported intervention programme. It helps to technically validate the results obtained in the other stages relating to the development of the solution. The data analysis resulting from the proof of concept confirms that the stress experienced by parents who followed the mHealth-supported intervention programme was significantly lower than among those who did not follow it. This implies an improvement in the emotional health not only of the parents but also of their child. In fact, the babies of couples who followed the mHealth-supported programme weigh more than the babies of couples under traditional care. In terms of user acceptance and usability, the analysis confirms that mothers place greater value on the app design, usefulness and ease of use and are generally more satisfied than their partners. Although these results are promising in comparison with more traditional and other more recent technology-based approaches.

Evaluation of the AJCC Eighth-Edition Prognostic Staging System for Breast Cancer in a Latin American Cohort.

BACKGROUND: The staging of breast cancer has been based on tumor size, lymph node involvement, and presence or absence of distant metastases. The American Joint Committee on Cancer (AJCC) staging system in its eighth edition incorporates hormone receptors, human epidermal growth factor receptor 2 (HER2), and histologic grade due to their prognostic importance. In Latin America, however, the impact of the new edition is unknown. This article evaluates the performance of the AJCC eighth-edition staging system in a cohort of patients with breast cancer at a reference center in Colombia. METHODS: The study investigated a descriptive cohort of 912 patients who received complete treatment for non-metastatic invasive breast cancer and had information on the anatomic stage and biologic factors,. All the patients were restaged using the AJCC eighth-edition classification. Changes in clinical stages and differences between the two classifications were compared. RESULTS: The study enrolled 912 patients. Changes in staging occurred for 54.82% (downstaging for 40.3% and upstaging for 14.47%) of these patients. For recurrence-free survival, the C-Index of the eighth-edition AJCC was 0.726, and the AIC was 1323.7, whereas the C-Index of the seventh-edition AJCC was 0.731, and the AIC was 1314.3 (p = 0.99). CONCLUSIONS: The seventh and eighth editions of the AJCC staging system have similar predictive values in our population for recurrence-free survival. Future studies are necessary to evaluate the performance of the AJCC eighth-edition staging system in predicting overall survival.

Effect of a brief motivational intervention in the immediate postpartum period on breastfeeding self-efficacy: Randomized controlled trial.

Brief motivational intervention (bMI) is a therapeutic approach that encourages self-efficacy and may have a positive effect on breastfeeding self-efficacy (BSE). The purpose of this study was to analyze the effectiveness of a bMI in increasing BSE in women who started breastfeeding in the immediate postpartum period and to explore the roles of general self-efficacy and other baseline variables in this relationship. A randomized, parallel-group clinical trial was carried out. A bMI was compared with an educational session on breastfeeding. Changes in BSE and its dimensions and the interaction and mediation/moderation of general self-efficacy and other variables were analyzed. BSE increased in the bMI group from a mean baseline score of 59.14 (±9.35) to 64.62 (±7.91) at 1st month (p < 0.001). An interaction was found in that only women with higher education had an improvement in BSE during the follow-up period that was attributable to the bMI (mean difference between the bMI and the attention control group: 18.25 (95% confidence interval: 5.86-30.19; p = 0.006). This interaction was not found for the changes produced in the intrapersonal thoughts dimension of BSE, whose scores were higher in the bMI group at 3 and 6 months. General self-efficacy exerted a moderating effect on the association of bMI with BSE change. The effect of bMI was no longer significant when the general self-efficacy score was above 84. Thus, bMI is effective in increasing BSE. This effectiveness was limited by the mother's educational level and moderated by baseline general self-efficacy.

Changes in the Cellular Distribution of Tyrosine Phosphorylation and Its Relationship with the Acrosomal Exocytosis and Plasma Membrane Integrity during In Vitro Capacitation of Frozen/Thawed Bull Spermatozoa.

During sperm capacitation, intracellular signaling leads to protein tyrosine phosphorylation (PTP) of multiple cellular structures. However, the connection of this molecular signaling to the physiology of capacitated spermatozoa is not completely understood. This is the case of the short lifespan of capacitated spermatozoa and their increased susceptibility to initiate acrosomal exocytosis (AE) during incubation. Herein, by employing frozen/thawed bull spermatozoa, we aimed to study the relationship between PTP with AE and with plasma membrane integrity (PMI) at the cellular level. For this, we employed double staining following immunofluorescence for PTP combined with fluorescence probes for the acrosome (PNA-FITC) and PMI (LIVE/DEAD Fixable Dead Cell Stain Kit). Our results revealed that the presence of PTP at sperm head was less abundant in the sperm fraction that triggered the AE after 3 h of incubation under capacitating conditions, or by its induction with calcium ionophore, compared to the unreacted fraction. Furthermore, PTP at the equatorial region of the head (PTP-EQ) was enriched in the fraction showing damaged membrane while induction of AE with calcium ionophore did not alter the PMI and its relation to PTP-EQ. These results suggest that spontaneous AE and induced AE trigger similar cellular events regarding PTP and the spermatozoa showing PTP-EQ are more prone to suffer plasma membrane damage.

Pathological Response to Neoadjuvant Chemotherapy and the Molecular Classification of Locally Advanced Breast Cancer in a Latin American Cohort.

BACKGROUND: The majority of patients with breast cancer in Colombia are admitted into oncological centers at locally advanced stages of the disease (53.9%). The aim of this study was to describe the pathological response obtained with neoadjuvant chemotherapy (NACT) according to the molecular classification of breast cancer in patients with locally advanced tumors treated within the National Cancer Institute (NCI) Functional Breast Cancer Unit (FBCU) in Bogotá, Colombia. MATERIALS AND METHODS: This was an observational, descriptive, historical cohort study of patients with locally advanced breast cancer treated within the NCI FBCU. RESULTS: We included 414 patients who received NACT and surgical management. Most patients had luminal B HER2-negative tumors (n = 134, 32.4%). The overall rate of pathological complete response (pCR) ypT0/ypN0 was 15.2% (n = 63). Tumors that presented the highest rate of pCR were pure HER2, at 40.5% (n = 15; odds ratio [OR], 6.7); however, with a follow-up of 60 months, only the triple negative tumors presented a statistically significant difference for event-free survival (EFS; median recurrence time, 18 months; range, 1-46) and overall survival (OS; median follow-up, 31 months; range 10-57). The molecular subtype that most recurrences presented was luminal B HER2 negative, at 38.3% (n = 28). The majority of recurrences (93.2 %; n = 68; OR, 5.9) occurred in patients in whom no pathological response was obtained (Chevallier 3 and 4). CONCLUSION: Pathological response in locally advanced tumors is related to the molecular subtype of breast cancer, finding higher pCR rates in pure HER2 and triple-negative tumors. A direct relationship was found between disease recurrences and the pathological response, evidencing greater tumor recurrence in patients who did not respond to NACT (Chevallier 3 and 4). EFS and OS were greater in patients with pCR, with statistical significance only in triple-negative tumors. IMPLICATIONS FOR PRACTICE: This research article is of scientific interest, because it describes the clinical and pathological features and analyzes the correlation between pathological response to neoadjuvant chemotherapy and the molecular classification of locally advanced breast cancer in patients treated in the National Cancer Institute in Bogotá, Colombia. It was found that pathological response is related to the molecular subtype of breast cancer. In addition, there is a direct relationship between disease recurrences and pathological response. The survival results were greater in patients with pathological complete response.

Predominance of deterministic microbial community dynamics in salterns exposed to different light intensities.

While the dynamics of microbial community assembly driven by environmental perturbations have been extensively studied, our understanding is far from complete, particularly for light-induced perturbations. Extremely halophilic communities thriving in coastal solar salterns are mainly influenced by two environmental factors-salt concentrations and high sunlight irradiation. By experimentally manipulating light intensity through the application of shading, we showed that light acts as a deterministic factor that ultimately drives the establishment of recurrent microbial communities under near-saturation salt concentrations. In particular, the stable and highly change-resistant communities that established under high-light intensities were dominated (>90% of metagenomic reads) by Haloquadratum spp. and Salinibacter spp. On the other hand, under 37-fold lower light intensity, different, less stable and change-resistant communities were established, mainly dominated by yet unclassified haloarchaea and relatively diverse photosynthetic microorganisms. These communities harboured, in general, much lower carotenoid pigment content than their high-irradiation counterparts. Both assemblage types appeared to be highly resilient, re-establishing when favourable conditions returned after perturbation (i.e. high-irradiation for the former communities and low-irradiation for the latter ones). Overall, our results revealed that stochastic processes were of limited significance to explain these patterns.

The peripheral atherosclerotic profile in patients with type 1 diabetes warrants a thorough vascular assessment of asymptomatic patients.

AIMS: Epidemiological data on subclinical atherosclerotic disease in type 1 diabetes mellitus (DM1) are scarce. We aimed to estimate the subclinical atherosclerosis profile of asymptomatic patients with DM1 and an abnormal ankle-brachial index (ABI). MATERIAL AND METHODS: In a cross-sectional design (ClinicalTrials.gov Identifier: NCT02910271), we estimated ABI in 289 consecutive asymptomatic patients with DM1. An abnormal ABI led to measurements of toe-brachial index (TBI) and peripheral doppler ultrasound (DUS) to diagnose peripheral artery disease (PAD) and/or atherosclerotic carotid plaques (ACP). RESULTS: A reduced (≤0.9) or increased (>1.2) ABI was detected in 17 (6%) and 75 (26%) patients, respectively. PAD was confirmed by TBI and DUS in 9 (53%) patients with a reduced ABI and 28 (37%) patients with an increased ABI, resulting in a 12.8% (9.4-17.2) prevalence of asymptomatic PAD. Fourteen patients with an abnormal ABI also exhibited ACP [4.8% (2.9-7.9)], with 64% of these patients showing bilateral disease. Artery stenosis was mild or moderate in 21% and 29% of patients, respectively. Thus, 46 [16% (12-21)] patients showed asymptomatic PAD, ACP, or both. According to our data, we would have to explore three asymptomatic patients with DM1 and normal pulses to unmask one case of PAD, and seven asymptomatic patients showing abnormal ABI values to detect one carotid disease. CONCLUSIONS: Peripheral artery disease is often undiagnosed in asymptomatic patients with DM1. However, its presence may change medical management in a substantial percentage of cases, highlighting the potential benefit of a thorough vascular assessment on these patients.

Clostridium difficile infection in patients with chronic kidney disease in Mexico
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BACKGROUND: Clostridium difficile infection (CDI) is a leading cause of healthcare-associated diarrhea worldwide. Patients with chronic kidney disease (CKD) are especially vulnerable, as they are exposed to CDI risk factors including frequent antibiotics. MATERIALS AND METHODS: In order to identify the risk factors for CDI in CKD patients, a 33-month long case-control study was carried out at a tertiary-care hospital in Mexico. CDI was confirmed at the genetic level, and univariate and multivariate analyses were performed to identify the association between risk factors, biomarkers, and outcome options (survival, relapse, death). RESULTS: Among the 1,198 patients with healthcare-associated diarrhea, 354 (29.5%) were CDI cases. 105 (29.6%) CDI cases and 192 (22.7%) controls had CKD. 84 (80%) CKD+CDI cases had a favorable outcome, 10 (9.5%) relapsed, and the 3-month mortality rate included 11 (10.4%) patients. Compared with controls, CDI cases had more previous hospitalizations (63.8 vs. 46.9%, p = 0.005), abdominal distension (46.7 vs. 36.5%, p = 0.056), abdominal pain (60.0 vs. 41.1%, p = 0.002), and polymorphonuclear leukocyte in stools (71.4 vs. 40.5%, p = 0.001) as well as poorer outcomes at 3 months. The patients in the 027-strain group were older, and most of the patients had CKD stage 5 (88.5% vs. 71.1%, p = 0.007), while CKD stage-4 patients were more frequently infected with non-027 strains. In the multivariate analysis of risk factors for CDI, only previous antibiotic exposure (odds ratio = 2.01, 95% confidence interval: 1.05 - 3.84; p = 0.034) was independently associated with CDI in patients with CKD stage 5. CONCLUSION: Mexican patients with CKD are at risk for CDI. This susceptible group should be protected by promoting appropriate guidelines.
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Economic Analysis of the Reduction of Blood Transfusions during Surgical Procedures While Continuous Hemoglobin Monitoring Is Used.

BACKGROUND: Two million transfusions are performed in Spain every year. These come at a high economic price for the health system, increasing the morbidity and mortality rates. The way of obtaining the hemoglobin concentration value is via invasive and intermittent methods, the results of which take time to obtain. The drawbacks of this method mean that some transfusions are unnecessary. New continuous noninvasive hemoglobin measurement technology can save unnecessary transfusions. METHODS: A prospective study was carried out with a historical control of two homogeneous groups. The control group used the traditional hemoglobin measurement methodology. The experimental group used the new continuous hemoglobin measurement technology. The difference was analyzed by comparing the transfused units of the groups. The economic savings was calculated by multiplying the cost of a transfusion by the difference in units, taking into account measurement costs. RESULTS: The percentage of patients needing a transfusion decreased by 7.4%, and the number of transfused units per patient by 12.56%. Economic savings per patient were €20.59. At the national level, savings were estimated to be 13,500 transfusions (€1.736 million). CONCLUSIONS: Constant monitoring of the hemoglobin level significantly reduces the need for blood transfusions. By using this new measurement technology, health care facilities can significantly reduce costs and improve care quality.

The low diverse gastric microbiome of the jellyfish Cotylorhiza tuberculata is dominated by four novel taxa.

Cotylorhiza tuberculata is an important scyphozoan jellyfish producing population blooms in the Mediterranean probably due to pelagic ecosystem's decay. Its gastric cavity can serve as a simple model of microbial-animal digestive associations, yet poorly characterized. Using state-of-the-art metagenomic population binning and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH), we show that only four novel clonal phylotypes were consistently associated with multiple jellyfish adults. Two affiliated close to Spiroplasma and Mycoplasma genera, one to chlamydial 'Candidatus Syngnamydia', and one to bacteroidetal Tenacibaculum, and were at least one order of magnitude more abundant than any other bacteria detected. Metabolic modelling predicted an aerobic heterotrophic lifestyle for the chlamydia, which were found intracellularly in Onychodromopsis-like ciliates. The Spiroplasma-like organism was predicted to be an anaerobic fermenter associated to some jellyfish cells, whereas the Tenacibaculum-like as free-living aerobic heterotroph, densely colonizing the mesogleal axis inside the gastric filaments. The association between the jellyfish and its reduced microbiome was close and temporally stable, and possibly related to food digestion and protection from pathogens. Based on the genomic and microscopic data, we propose three candidate taxa: 'Candidatus Syngnamydia medusae', 'Candidatus Medusoplasma mediterranei' and 'Candidatus Tenacibaculum medusae'.

The anatomical outcome of robotic sacrocolpopexy for treatment of pelvic organ prolapse: a comparison of obese and non-obese patients.

The purpose of this study is to compare the anatomical outcome of robotic sacrocolpopexy for pelvic organ prolapse in women with a body mass index (BMI) of 30 and higher to those with a BMI under 30. This is a retrospective chart review. POP-Q measurements preoperatively and 12 months postoperatively were evaluated using non-parametric statistical analysis. The primary outcome was to compare postoperative POPQ measurements at 12 months following surgery. Secondary outcomes were age at the time of surgery, mesh erosion rate, blood loss, length of hospital stay, and baseline anatomical support. A total of 71 patients were identified: 44 patients had a BMI below 30, and 27 had a BMI equal to or greater than 30. We found no significant relationship between BMI and anatomical support at 12 months post operation. However, obese patients were younger at the time of prolapse surgery (53.6 versus 60.6 years of age, p=0.0022). In regards to the ICS prolapse stage, no difference was found between obese and non-obese patients (2.81 versus 2.95, p=0.17).

Characterization of Microalgae Biomass-Based Composites Obtained through Rotational Molding.

The wide range of applications and the numerous advantages of plastics have led to their excessive use, with subsequent damage to ecosystems. As an environmentally friendly alternative, biocomposites have gained much attention, and microalgae have become a potential source for their production. In this study, the use of washed and unwashed Spirulina in polyethylene-based composites has been evaluated as a way to prevent the thermooxidation of polyethylene, while at the same time, reducing the amount of virgin plastic used. Biocomposites were produced by rotomolding, testing different biomass contents and determining their mechanical and thermal performances as well as their water uptake level. Composites with up to 15% of biomass (by weight), a particularly high ratio for rotomolding, were satisfactorily produced. Using 5% of both biomasses did not significantly modify the behavior when compared with the neat PE samples' properties. For higher loadings, the use of non-washed biomass allowed us to obtain better properties, with added benefits related to using an unwashed biomass (less water consumption, lower costs and fewer environmental impacts). On the other hand, this study showed a promising beneficial effect on the thermooxidative resistance of composites, as the oxidation induction times were notably increased with biomass addition.

Impact of suppression of the SOS response on protein expression in clinical isolates of Escherichia coli under antimicrobial pressure of ciprofloxacin.

Introduction/objective: Suppression of the SOS response in combination with drugs damaging DNA has been proposed as a potential target to tackle antimicrobial resistance. The SOS response is the pathway used to repair bacterial DNA damage induced by antimicrobials such as quinolones. The extent of lexA-regulated protein expression and other associated systems under pressure of agents that damage bacterial DNA in clinical isolates remains unclear. The aim of this study was to assess the impact of this strategy consisting on suppression of the SOS response in combination with quinolones on the proteome profile of Escherichia coli clinical strains. Materials and methods: Five clinical isolates of E. coli carrying different chromosomally- and/or plasmid-mediated quinolone resistance mechanisms with different phenotypes were selected, with E. coli ATCC 25922 as control strain. In addition, from each clinical isolate and control, a second strain was created, in which the SOS response was suppressed by deletion of the recA gene. Bacterial inocula from all 12 strains were then exposed to 1xMIC ciprofloxacin treatment (relative to the wild-type phenotype for each isogenic pair) for 1 h. Cell pellets were collected, and proteins were digested into peptides using trypsin. Protein identification and label-free quantification were done by liquid chromatography-mass spectrometry (LC-MS) in order to identify proteins that were differentially expressed upon deletion of recA in each strain. Data analysis and statistical analysis were performed using the MaxQuant and Perseus software. Results: The proteins with the lowest expression levels were: RecA (as control), AphA, CysP, DinG, DinI, GarL, PriS, PsuG, PsuK, RpsQ, UgpB and YebG; those with the highest expression levels were: Hpf, IbpB, TufB and RpmH. Most of these expression alterations were strain-dependent and involved DNA repair processes and nucleotide, protein and carbohydrate metabolism, and transport. In isolates with suppressed SOS response, the number of underexpressed proteins was higher than overexpressed proteins. Conclusion: High genomic and proteomic variability was observed among clinical isolates and was not associated with a specific resistant phenotype. This study provides an interesting approach to identify new potential targets to combat antimicrobial resistance.

Diagnostic performance of sixteen biomarkers for MASLD: A study in a Mexican cohort.

BACKGROUND AND AIMS: Metabolic Dysfunction-associated Steatotic Liver Disease (MASLD) poses a heightened cardiovascular risk. Identifying efficient biomarkers for early MASLD detection in resource-limited Latin American regions is crucial. We aimed to evaluate the diagnostic efficacy of sixteen biomarkers for MASLD in Mexican individuals. METHODS: In this cross-sectional and analytical study, steatosis was assessed using vibration-controlled transient elastography. MASLD was defined according to international standards. Assessed biomarkers included: Visceral Fat (VF), Waist Circumference (WC), Waist-Height Ratio (WHtr), Waist-Hip Ratio (WHr), Visceral Adiposity Index (VAI), Hepatic Steatosis Index (HSI), Body Mass Index (BMI), Homeostatic Model Assessment (HOMA), Weight-Adjusted-Waist Index (WWI), Lipid Accumulation Product (LAP), Uric Acid-Creatinine Ratio (UACR), Triglyceride-Glucose Index (TyG) and its variants TyG-WC, TyG-HDL, TyG-BMI, TyG-WHtr. RESULTS: 161 participants were included, of which 122 met MASLD criteria (56 % women, age 53.9 years [47.5-64]) and 39 were healthy controls (76 % women, age 52 [45-64]). The AUROCs of the biomarkers for MASLD were: TyG-WC (0.84), LAP (0.84), TyG-BMI (0.82), TyG-WHtr (0.80), WC (0.78), TyG (0.77), WHtr (0.75), BMI (0.76), VF (0.75), HSI (0.75), TyG-HDL (0.75), WHr (0.72), VAI (0.73), UA/CR (0.70), HOMA (0.71), and WWI (0.69). Sex-based differences were observed. After adjusting for sociodemographic variables, the TyG-WC index was the best predictor of MASLD. CONCLUSIONS: In conclusion, our results underscore the potential of several noninvasive biomarkers for MASLD assessment in a Mexican population, highlighting variations in diagnostic efficacy and cut-off values between sexes. After adjusting, TyG-WC was the best MASLD predictor.

DUSP1 and SOX2 expression determine squamous cell carcinoma of the salivary gland progression.

Salivary gland squamous cell carcinomas (SG-SCCs) constitute a rare type of head and neck cancer which is linked to poor prognosis. Due to their low frequency, the molecular mechanisms responsible for their aggressiveness are poorly understood. In this work we studied the role of the phosphatase DUSP1, a negative regulator of MAPK activity, in controlling SG-SCC progression. We generated DUSP1 KO clones in A253 human cells. These clones showed a reduced ability to grow in 2D, self-renew in ECM matrices and to form tumors in immunodeficient mice. This was caused by an overactivation of the stress and apoptosis kinase JNK1/2 in DUSP1-/+ clones. Interestingly, RNAseq analysis revealed that the expression of SOX2, a well-known self-renewal gene was decreased at the mRNA and protein levels in DUSP1-/+ cells. Unexpectedly, CRISPR-KO of SOX2 did not recapitulate DUSP1-/+ phenotype, and SOX2-null cells had an enhanced ability to self-renew and to form tumors in mice. Gene expression analysis demonstrated that SOX2-null cells have a decreased squamous differentiation profile -losing TP63 expression- and an increased migratory phenotype, with an enhanced epithelial to mesenchymal transition signature. In summary, our data indicates that DUSP1 and SOX2 have opposite functions in SG-SCC, being DUSP1 necessary for tumor growth and SOX2 dispensable showing a tumor suppressor function. Our data suggest that the combined expression of SOX2 and DUSP1 could be a useful biomarker to predict progression in patients with SG-SCCs.