Hydrocortisone cardioprotection in ischaemia/reperfusion injury involves antioxidant mechanisms.

BACKGROUND: Glucocorticoid (GR) and mineralocorticoid (MR) receptors are highly expressed in cardiac tissue, and both can be activated by corticosteroids. MR activation, in acute myocardial infarction (AMI), worsens cardiac function, and increase NHE activity contributing to the deleterious process. In contrast, effects of GR activation are not fully understood, probably because of the controversial scenario generated by using different doses or potencies of corticosteroids. AIMS: We tested the hypothesis that an acute dose of hydrocortisone (HC), a low-potency glucocorticoid, in a murine model of AMI could be cardioprotective by regulating NHE1 activity, leading to a decrease in oxidative stress. MATERIALS AND METHODS: Isolated hearts from Wistar rats were subjected to regional ischemic protocol. HC (10 nmol/L) was added to the perfusate during early reperfusion. Infarct size and oxidative stress were determined. Isolated papillary muscles from non-infarcted hearts were used to evaluate HC effect on sodium-proton exchanger 1 (NHE1) by analysing intracellular pH recovery from acute transient acidosis. RESULTS: HC treatment decreased infarct size, improved cardiac mechanics, reduced oxidative stress after AMI, while restoring the decreased level of the pro-fusion mitochondrial protein MFN-2. Co-treatment with the GR-blocker Mifepristone avoided these effects. HC reduced NHE1 activity by increasing the NHE1 pro-inhibiting Ser648 phosphorylation site and its upstream kinase AKT. HC restored the decreased AKT phosphorylation and anti-apoptotic BCL-2 protein expression detected after AMI. CONCLUSIONS: Our results provide the first evidence that acute HC treatment during early reperfusion induces cardioprotection against AMI, associated with a non-genomic HC-triggered NHE1 inhibition by AKT and antioxidant action that might involves mitochondrial dynamics improvement.

Development and validation of the Gastrointestinal Symptom Severity Scale in Spanish children and adolescents.

Functional gastrointestinal disorders (FGIDs) are characterized by chronic or recurrent gastrointestinal symptoms (GS) that are not explained by structural or biochemical abnormalities. FGIDs are related to lower quality of life, increased demands on medical resources, and greater somatization and emotional instability. Furthermore, GS appears to be an indicator of dysbiosis in gut-microbiota, affecting the gut-microbiota-brain relationship. To develop and evaluate the psychometric properties of a new instrument called the Gastrointestinal Symptom Severity Scale (GSSS) using a web-based survey in a sample of neurotypical children and adolescents from Spain. Instrument development and validation processes were applied to the GSSS following its administration as part of an online survey. The sample included 1242 neurotypical children and adolescents. The mean age of participants was 13.95 years, with a standard deviation of 1.37 years. Overall, 13.8% suffered infectious diarrhea, 12.6% suffered abdominal pain, 5% suffered dyspepsia and 2.6% suffered gastro-esophageal reflux. A single-factor model produced good fit indices. Furthermore, internal consistency and test-retest reliability outcomes were acceptable. The GSSS was found to have acceptable metric measurement invariance. Significant correlations with other instruments were produced and were of expected direction and magnitude, confirming scale validity for hypothesis testing.     Conclusions: The GSSS shows promising psychometric properties for assessing GS in neurotypical Spanish adolescents and children. What is Known: • To the best of our knowledge, instruments assessing the severity of gastrointestinal symptoms in children and adolescents are still too few. What is New: • The GSSS shows promising psychometric properties for assessing GS in neurotypical adolescents and children. The GSSS may help improve understanding of GS involvement in the gut-brain microbiota axis in children and adolescents.

A Systematic Review of the Effectiveness of Non-Pharmacological Therapies Used by Nurses in Children Undergoing Surgery.

OBJECTIVE: The aim of this study was to identify non-pharmacological pain relief therapies in children undergoing surgery. DESIGN AND DATA SOURCES: Using keywords extracted from Medical Subject Headings and "Descriptores en Ciencias de la Salud" we searched for articles in the Web of Science, Scopus, Cuiden, PubMed, and CINHAL databases from the last five years, and performed a reverse search. We assessed the documentary quality of the articles using various standardized instruments. RESULTS: The final review included eleven studies. In terms of cognitive-behavioral techniques, there is evidence that both music and video therapy are effective in reducing postoperative pain in children in seven studies, and therapeutic play in five studies. Other methods used less frequently but found to be effective included laughter therapy in one study and deep breathing in another. Regarding physical methods of pain relief, massage was found to be an effective non-pharmacological therapy for reducing pediatric postoperative pain in two studies and ineffective in another. CONCLUSIONS: In this study, we highlight the importance of non-pharmacological therapies in pediatric postoperative pain management. Cognitive-behavioral techniques, especially music therapy, video therapy, and therapeutic play, reduce pediatric postoperative pain. They are therefore effective therapies that nurses can use in this area. Further research into the effectiveness of storytelling is necessary, as the evidence is not entirely conclusive. More evidence is also needed on physical methods of pain relief, particularly massage.

Development and validation of assessment instruments for cervical collar and spinal board placement in simulated environments for nursing students in the care of polytrauma patients.

BACKGROUND: Multiple trauma injuries are the leading cause of death and disability in people under the age of 45 and require prompt and specialised care. However, medical and nursing education programmes do not always include specific training in emergency pre-hospital care, resulting in a lack of basic practical skills in trauma management. OBJECTIVE: To develop and validate two instruments for assessing nursing students' competence in cervical collar and spinal board application in simulated pre-hospital emergency scenarios. METHOD: This is an instrumental study that involves the development of two assessment instruments and the evaluation of their psychometric properties in a sample of 392 nursing students. Content validity was assessed using expert judgement, by calculating the content validity ratio (CVR) for each item and the scale level content validity index average (S-CVI/Ave) for the instruments. Exploratory factor analysis using the MINRES extraction method and Promax rotation was performed to analyse the performance of the items and structure of the rubrics. Internal consistency was analysed using the Omega coefficient and inter-rater agreement was assessed using Cohen's Kappa coefficient. RESULTS: Initially, two rubrics were obtained: one with six items for cervical collar placement (S-CVI/Ave = 0.86) and one with nine items for spinal board placement (S-CVI/Ave = 0.81). Both had a single-factor structure, with all items having factor loadings greater than 0.34 for the cervical collar rubric and 0.56 for the spinal board rubric, except for item 2 of the cervical collar rubric (λ = 0.24), which was subsequently removed. The final cervical collar rubric (five items) had an overall internal consistency of 0.84 and the spinal board rubric had an overall internal consistency of 0.90, calculated using the Omega statistic. The weighted Kappa coefficient for each item ranged from acceptable (0.32) to substantial (0.79). These results show that we have successfully developed two sufficiently valid instruments to assess the immobilisation competencies proposed in the objective of the study. CONCLUSION: Whilst further research is needed to fully establish their psychometric properties, these instruments offer a valuable starting point for evaluating nursing students' competence in cervical collar and spinal board application in simulated pre-hospital scenarios.

Psychometric properties of parental stress scales used in paediatric health care settings: A systematic review1.

AIM: To identify scales that assess parental stress in the paediatric clinical population and to analyse their psychometric properties. METHODS: Four electronic databases (PubMed, Web of Science, PsycINFO, and Scopus) and metasearch engines (Google Scholar and Open Grey) were searched with no time period limitations. Methodological quality was assessed using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach modified by COSMIN. Finally, recommendations were made for the instruments with the highest quality of evidence. RESULTS: A total of 38 studies reporting on 11 different instruments for assessing parental stress in the paediatric clinical setting were included. Six instruments were 'A' rated (recommended) in the final phase in line with COSMIN guidelines. The Paediatric Inventory for Parents was the instrument that evaluated the highest number of psychometric properties and obtained the highest methodological quality, global assessment, and quality of evidence for the different psychometric properties. CONCLUSIONS: This systematic review provides an overview of the measurement properties of the parental stress instruments used in the paediatric clinical setting. The Paediatric Inventory for Parents stands out as being one of the most robust instruments for measuring stress in parents with a hospitalised or sick child. Evidence needs to be generated for all the parental stress scales used in the clinical setting. IMPACT: Given that the psychometric properties of the existing parental stress scales used in paediatric health care settings have not been systematically assessed, the present review utilised comprehensive methods according to COSMIN. NO PATIENT OR PUBLIC CONTRIBUTION: REPORTING METHOD: PRISMA statement and COSMIN reporting guidelines for studies on measurement properties of patient-reported outcome measures.

Factors associated with non-urgent presentations in the paediatric emergency department using Andersen's behavioural model: A cross-sectional descriptive study.

OBJECTIVES: To explore the rate of NUPs and associated factors in the PED of the 'Hospital Universitario y Politécnico La Fe' in Valencia (Spain) using Andersen's Behavioural Model. METHODS: We conducted a descriptive cross-sectional study using Andersen's Behavioural Model in parents visiting the PED with their children at the 'Hospital Universitario y Politécnico La Fe' in Valencia (Spain). RESULTS: The study involved a total of 530 participants, of whom 419 (79%) had made an NUP. The predisposing factors identified were: (I) paediatric patients brought in by their fathers (OR = 0.460; p = 0.005), (II) lower educational attainment (OR = 3.841; p = 0.000), (III) first-time parenthood (OR = 2.335; p = 0.000) and (IV) higher parental stress (OR = 1.974; p = 0.023). The enabling factors included: (I) responsibility for a significant part of the childcare shared with others (OR = 0.348; p = 0.041) and (II) the perception that PEDs provide better care than primary care (PC) services (OR = 1.628; p = 0.005). The need factors were: (I) existing chronic illness in the child seeking care (OR = 0.343; p = 0.000) and (II) the perceived severity of the urgency (OR = 0.440; p = 0.031). CONCLUSIONS: The NUP rates found in this study are similar to those found internationally. In accordance with Andersen's Behavioural Model, we identify predisposing, enabling and need factors to explain the multifactorial nature of NUPs in PEDs. IMPLICATIONS FOR PRACTICE: Identifying the factors associated with NUPs enables interventions to be targeted at those groups most likely to engage in NUPs, thereby optimising the functioning of the PED and improving the well-being of children and families. These interventions should focus on improving parental health literacy, providing education on making appropriate decisions about accessing health services and recognising severe symptoms in children, as well as improving access to high-quality PC services. Providing support to parents during the transition to parenthood would also be beneficial. REPORTING METHOD: This paper adheres to the STROBE initiative guidelines. CONTRIBUTION FROM PATIENTS OR MEMBERS OF THE PUBLIC: Participants, who voluntarily agreed to take part, contributed to the study by completing a paper-based questionnaire containing all the study variables as prepared by the research team.

A descriptive cross-sectional study on eating disorders, suicidal thoughts, and behaviors among adolescents in the Valencian community (Spain). The pivotal role of school nurses.

PURPOSE: The aims of this study were: 1) to describe the rates of risk of having an Eating Disorder (ED) and the rates of suicidal thoughts and behaviors, and 2) to examine the relationship between the risk of having an ED with suicidal thoughts and behaviors in adolescents enrolled in educational centers in the Community of Valencia (Spain). DESIGN AND METHODS: A cross-sectional study was conducted with 718 adolescents between September 2019 and July 2020 in five schools in the Community of Valencia (Spain). RESULTS: The adolescents studied, mostly females, are at risk of having an ED (18.6% to 30.8%) and experiencing suicidal thoughts (23% to 30.7%) and behaviors (2.2% to 6.2%). A strong association was found between EDs and suicidal thoughts and behaviors in both sexes. This association was higher in females with positive EAT-26 scores (OR: 2.09; 95% CI: 1.35-3.24) and in males with positive SCOFF scores (OR: 4.66; 95% CI: 2.40-9.02). Suicidal behaviors were positively associated with both EAT-26 (OR: 2.58; 95% CI: 1.17-5.67) and SCOFF (OR: 1.89; 95% CI: 1.21-2.26) scores in females. CONCLUSIONS: A considerable number of adolescents, females in particular, are at risk of having an ED and of experiencing suicidal thoughts and behaviors, establishing a strong link between EDs and suicidal tendencies. PRACTICAL IMPLICATIONS: The study highlights the importance of establishing national and regional regulations to ensure the availability of school nurses in the Community of Valencia (Spain). Collaboration between school nurses, educators, and policy makers is critical to the early detection of problems and the provision of support to both adolescents and families.

A comprehensive study of glucose and oxygen gradients in a scaled-down model of recombinant HuGM-CSF production in thermoinduced Escherichia coli fed-batch cultures.

The effect of gradients of elevated glucose and low dissolved oxygen in the addition zone of fed-batch E. coli thermoinduced recombinant high cell density cultures can be evaluated through two-compartment scale-down models. Here, glucose was fed in the inlet of a plug flow bioreactor (PFB) connected to a stirred tank bioreactor (STB). E. coli cells diminished growth from 48.2 ± 2.2 g/L in the stage of RP production if compared to control (STB) with STB-PFB experiments, when residence time inside the PFB was 25 s (34.1 ± 3.5 g/L) and 40 s (25.6 ± 5.1 g/L), respectively. The recombinant granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) production decreased from 34 ± 7% of RP in inclusion bodies (IB) in control cultures to 21 ± 8%, and 7 ± 4% during the thermoinduction production phase when increasing residence time inside the PFB to 25 s and 40 s, respectively. This, along with the accumulation of acetic and formic acid (up to 4 g/L), indicates metabolic redirection of central carbon routes through metabolic flow and mixed acid fermentation. Special care must be taken when producing a recombinant protein in heat-induced E. coli, because the yield and productivity of the protein decreases as the size of the bioreactors increases, especially if they are carried at high cell density.

Thermoinduced recombinant E. coli grew less in a two-compartment scale-down model.Heat-inducible E. coli cultures at a large scale significantly decrease recombinant protein production.The accumulation of acetic and formic acid increases when E. coli is exposed to glucose and oxygen gradients.The axial flow pattern inside the PFB mimics glucose and dissolved oxygen gradients at the industrial scale.

Patchy colloidal gels under the influence of gravity.

In this contribution, gravitational effects in gel-forming patchy colloidal systems are studied. We focus on how the gel structure is modified by gravity. Through Monte Carlo computer simulations of gel-like states recently identified by the rigidity percolation criterion [J. A. S. Gallegos et al., Phys. Rev. E 104, 064606 (2021)], the influence of the gravitational field, characterized by the gravitational Péclet number, Pe, on patchy colloids is studied in terms of the patchy coverage, χ. Our findings point out that there exists a threshold Péclet number, Peg, that depends on χ above which the gravitational field enhances the particle bonding and, in consequence, promotes the aggregation or clustering of particles; the smaller the χ value, the higher the Peg. Interestingly, when χ ∼ 1 (near the isotropic limit), our results are consistent with an experimentally determined threshold Pe value where gravity affects the gel formation in short-range attractive colloids. In addition, our results show that the cluster size distribution and the density profile undergo variations that lead to changes in the percolating cluster, i.e., gravity is able to modify the structure of the gel-like states. These changes have an important impact on the structural rigidity of the patchy colloidal dispersion; the percolating cluster goes from a uniform spatially network to a heterogeneous percolated structure, where an interesting structural scenario emerges, namely, depending on the Pe value, the new heterogeneous gel-like states can coexist with both diluted and dense phases or they simply reach a crystalline-like state. In the isotropic case, the increase in the Pe number can shift the critical temperature to higher temperatures; however, when Pe > 0.01, the binodal disappears and the particles fully sediment at the bottom of the sample cell. Furthermore, gravity moves the rigidity percolation threshold to lower densities. Finally, we also note that within the values of the Péclet number here explored, the cluster morphology is barely altered.

Lipid-Like Biofilm from a Clinical Brain Isolate of Aspergillus terreus: Quantification, Structural Characterization and Stages of the Formation Cycle.

Invasive infections caused by filamentous fungi have increased considerably due to the alteration of the host's immune response. Aspergillus terreus is considered an emerging pathogen and has shown resistance to amphotericin B treatment, resulting in high mortality. The development of fungal biofilm is a virulence factor, and it has been described in some cases of invasive aspergillosis. In addition, although the general composition of fungal biofilms is known, findings related to biofilms of a lipid nature are rarely reported. In this study, we present the identification of a clinical strain of A. terreus by microbiological and molecular tools, also its in vitro biofilm development capacity: (i) Biofilm formation was quantified by Crystal Violet and reduction of tetrazolium salts assays, and simultaneously the stages of biofilm development were described by Scanning Electron Microscopy in High Resolution (SEM-HR). (ii) Characterization of the organizational structure of the biofilm was performed by SEM-HR. The hyphal networks developed on the surface, the abundant air channels created between the ECM (extracellular matrix) and the hyphae fused in anastomosis were described. Also, the presence of microhyphae is reported. (iii) The chemical composition of the ECM was analyzed by SEM-HR and CLSM (Confocal Laser Scanning Microscopy). Proteins, carbohydrates, nucleic acids and a relevant presence of lipid components were identified. Some structures of apparent waxy appearance were highlighted by SEM-HR and backscatter-electron diffraction, for which CLSM was previously performed. To our knowledge, this work is the first description of a lipid-type biofilm in filamentous fungi, specifically of the species A. terreus from a clinical isolate.

Factors associated with the inappropriate use of the pediatric emergency department. A systematic review.

BACKGROUND: Pediatric emergency department (PED) admissions have risen in recent years, a trend not justified by the severity of the pathologies presented. The aim of this study is to analyse factors related to the inappropriate use of pediatric emergency departments. METHODS: This is a systematic review reported in accordance with the PRISMA statement. We searched the PubMed, Web of Science and Science Direct databases, using keywords extracted from MeSH, and conducted a reverse search using Google Scholar and Open Grey, for the period January 2017 to August 2022. The quality of the papers was assessed using STROBE, CASPe, AMSTAR-2, GRADE, Levels Of Evidence and Grades Of Recommendation. RESULTS: A total of 20 studies were selected. Factors related to inappropriate use included the younger age of children, black caregivers, lower socioeconomic status, lower parental educational attainment, perceived urgent demand for care, parental emotions in response to their children's health problems, psychological distress, the ineffective exercise of the parental role, the advantages of the PED and the nature of health insurance. CONCLUSIONS AND IMPLICATIONS: The results illustrate the heterogeneous nature of the phenomenon under investigation. Gaining an understanding of the factors related to the inappropriate demand of PEDs, from the perspective of health professionals, can help in developing interventions to reduce unnecessary consultations and relieve pressure on these healthcare services.

Development and validation of a parental competence questionnaire in the paediatric hospital emergency setting (ECP-U).

OBJECTIVE: To develop and validate a parental competence questionnaire for parents of children seeking care in hospital emergency departments. METHODS: An instrumental study of the development of an assessment questionnaire was carried out in three phases: 1) review of relevant measures and item generation, 2) content validity evaluation, 3) psychometric evaluation. Exploratory factor analysis was performed to examine the factorial structure. Internal consistency was evaluated using ordinal alpha. Hypothesis testing was determined between the resulting factors, the Parental Stress Scale and the State-Trait Anxiety Inventory. RESULTS: The participants were 270 parents of children aged 0-14 years old from a referral hospital in Valencia (Spain). An 18-item questionnaire was developed, comprising five factors that explain 53.0% of the variance: 1) "emotional management and expression", 2) "passive social support", 3) "parental agency", 4) "basic needs and care" and 5) "active social support". The internal consistency for the different factors was modest (>0.70). A negative correlation between the Parental Stress Scale and the parental competence questionnaire was found for most of the factors. CONCLUSIONS: This questionnaire on parental competence in the hospital emergency department (ECP-U) is a useful and simple self-report instrument for assessing the parental competence of parents with children in the emergency department. PRACTICAL IMPLICATIONS: The resulting questionnaire is of practical value to both healthcare professionals and researchers in this field. It can be administered quickly in clinical practice and used to identify parents' levels of parental competence and refer those with difficulties to appropriate support services.

Factor structure and validity of the Parental Competence Questionnaire in the Paediatric Hospital Emergency Setting (ECP-U).

OBJECTIVE: To confirm the structure and examine the psychometric properties of the Parental Competence Questionnaire in the Paediatric Hospital Emergency Setting (ECP-U). METHODS: An instrumental validation study of the ECP-U questionnaire and an examination of its psychometric properties were carried out. RESULTS: The participants were 260 mothers and fathers seeking care in the paediatric emergency department of a hospital in Valencia (Spain) with children aged 0 to 14 years old. The five-factor structure of the ECP-U was confirmed with excellent statistical fits. Second-order models and a more parsimonious four-factor structure with adequate but marginal fits are proposed. With the exception of the "parental agency" factor (in both models examined) and the "active social support" factor (in the original five-factor structure), the internal consistency of the different factors was modest (≥ 0.70). A negative correlation was found between the Parental Stress Scale and the ECP-U for most factors. CONCLUSIONS: Validity and reliability analyses indicate that the ECP-U is an instrument with modest psychometric properties. IMPLICATIONS FOR PRACTICE: The ECP-U is an instrument that can be used by future researchers to identify different levels of parental competence in paediatric hospital emergency departments. This will enable help to be given to families with parenting issues and problems. The underlying concern is to reduce the number of frequent users and "Non-Urgent Presentations" to paediatric emergency departments due to low parental competence.

The pre-induction temperature affects recombinant HuGM-CSF aggregation in thermoinducible Escherichia coli.

The overproduction of recombinant proteins in Escherichia coli leads to insoluble aggregates of proteins called inclusion bodies (IBs). IBs are considered dynamic entities that harbor high percentages of the recombinant protein, which can be found in different conformational states. The production conditions influence the properties of IBs and recombinant protein recovery and solubilization. The E. coli growth in thermoinduced systems is generally carried out at 30 °C and then recombinant protein production at 42 °C. Since the heat shock response in E. coli is triggered above 34 °C, the synthesis of heat shock proteins can modify the yields of the recombinant protein and the structural quality of IBs. The objective of this work was to evaluate the effect of different pre-induction temperatures (30 and 34 °C) on the growth of E. coli W3110 producing the human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) and on the IBs structure in a λpL/pR-cI857 thermoinducible system. The recombinant E. coli cultures growing at 34 °C showed a ~ 69% increase in the specific growth rate compared to cultures grown at 30 °C. The amount of rHuGM-CSF in IBs was significantly higher in cultures grown at 34 °C. Main folding chaperones (DnaK and GroEL) were associated with IBs and their co-chaperones (DnaJ and GroES) with the soluble protein fraction. Finally, IBs from cultures that grew at 34 °C had a lower content of amyloid-like structure and were more sensitive to proteolytic degradation than IBs obtained from cultures at 30 °C. Our study presents evidence that increasing the pre-induction temperature in a thermoinduced system allows obtaining higher recombinant protein and reducing amyloid contents of the IBs. KEY POINTS: • Pre-induction temperature determines inclusion bodies architecture • In pre-induction (above 34 °C), the heat shock response increases recombinant protein production • Inclusion bodies at higher pre-induction temperature show a lower amyloid content.

Photodegradation of Rituximab and Critical Evaluation of Its Sensibility to Electromagnetic Radiation.

Rituximab is a monoclonal antibody used in the treatment of lymphoma non-Hodgkin. This mAb is photosensitive as it is administrated to the patient by infusion/perfusion; therefore, photostability is a decisive factor in the efficacy of this biologic. To better understand the photodegradation mechanisms of Rituximab, this biologic was exposed to different irradiance conditions. We show in this study that this mAb photodegrade proportionally to irradiance intensities. The main modifications of Rituximab by irradiance correlate to the increase in aggregates, decrease in its Tm, acidic charge variants, oxidation of the Trp (36) in the heavy chain, and decrease in complement-dependent cytotoxicity (CDC) potency. To understand the relationship between real-life photo-exposition conditions and ICH standardized light tests, a full characterization was set up. Worst photo-stress cases were evaluated, 1 and 2 h under direct sunlight through a window, mimicking the ID65 electromagnetic radiation profile. Our results show that only exposition to direct sun irradiance during 2 h, (≈ 150 kluxes•h), increases critically soluble and insoluble aggregates, diminishing Tm, increasing acidic charge variants, and the photooxidation of the Trp (36) in the heavy chain measured by peptide mapping-RP-UPLC-MS. A decrease in CDC below 80% resulted under this condition, which correlates with physicochemical analyses. While inside light-room exposition (similar to ICH test) and ICH conditions do not have any contribution to the degradation of Rituximab measured by these physicochemical and biological analytical methods. These results indicate that exposition of Rituximab to below ≈ 75 kluxes•h of sun light cannot photodegrade critically this biologic inside of its primary container.

Potential-invariant network structures in Asakura-Oosawa mixtures with very short attraction range.

We systematically investigated the structure and aggregate morphology of gel networks formed by colloid-polymer mixtures with a moderate colloid volume fraction and different values of the polymer-colloid size ratio, always in the limit of short-range attraction. Using the coordinates obtained from confocal microscopy experiments, we determined the radial, angular, and nearest-neighbor distribution functions together with the cluster radius of gyration as a function of size ratio and polymer concentration. The analysis of the structural correlations reveals that the network structure becomes increasingly less sensitive to the potential strength with the decreasing polymer-colloid size ratio. For the larger size ratios, compact clusters are formed at the onset of network formation and become progressively more branched and elongated with increasing polymer concentration/attraction strength. For the smallest size ratios, we observe that the aggregate structures forming the gel network are characterized by similar morphological parameters for different values of the size ratio and the polymer concentration, indicating a limited evolution of the gel structure with variations of the parameters that determine the interaction potential between colloids.

Generalized equation of state for fluids: From molecular liquids to colloidal dispersions.

In this work, a new parameterization for the Statistical Association Fluid Theory for potentials of Variable Range (SAFT-VR) is coupled to the discrete potential theory to represent the thermodynamic properties of several fluids, ranging from molecular liquids to colloidal-like dispersions. In this way, this version of the SAFT-VR approach can be straightforwardly applied to any kind of either simple or complex fluid. In particular, two interaction potentials, namely, the Lennard-Jones and the hard-core attractive Yukawa potentials, are discretized to study the vapor-liquid equilibrium properties of both molecular and complex liquids, respectively. Our results are assessed with Monte Carlo computer simulations and available and accurate theoretical results based on the self-consistent Ornstein-Zernike approximation.

Detection and quantification of leached ethylene glycol in biopharmaceuticals by RP-UHPLC.

Biopharmaceuticals are in direct contact with different plastic materials, which can contribute to process-related impurities. Polyethylene terephthalate glycol (PETG) is used for storage and transportation of biopharmaceuticals and it is synthetized from the poly-condensation reaction between ethylene glycol, 1,4-cyclodimethanol and dimethyl terephthalate. PETG bottles are analyzed for such impurities prior to release; however, the nature of the pharmaceutical matrix can extract impurities, so it is important to measure these contaminants in biopharmaceuticals. This study shows a liquid chromatography method for the quantification of ethylene glycol in PETG materials as an alternative to the standard USP colorimetric method. The method is based on the derivatization of ethylene glycol with benzoyl chloride in a Schotten-Baumann reaction. We present a comprehensive method development and validation. The method allows the detection and quantification of leached and extracted ethylene glycol directly in biopharmaceuticals after years of storage in contact with PETG bottles. Results showed residual ethylene glycol in drug substances to a level of ≈  0.1-0.5 µg/mL exposed during 2-6 years of storage in PETG bottles and ≈ 0.2-0.9 µg/mL in biopharmaceuticals. Graphical abstract Biopharmaceuticals must be free or low concentration for leachables, FR-UHPLC-UV analysis is a precise and accurate analytical method for ethylene glycol measurement. This leachable is commonly present in products in direct contact with PETG plastic.

p38-MAP Kinase Negatively Regulates the Slow Force Response to Stretch in Rat Myocardium through the Up-Regulation of Dual Specificity Phosphatase 6 (DUSP6).

BACKGROUND/AIMS: Myocardial stretch increases cardiac force in two consecutive phases: The first one due to Frank-Starling mechanism, followed by the gradually developed slow force response (SFR). The latter is the mechanical counterpart of an autocrine/paracrine mechanism involving the release of angiotensin II (Ang II) and endothelin (ET) leading to Na⁺/H⁺ exchanger 1 (NHE-1) phosphorylation and activation. Since previous evidence indicates that p38-MAP kinase (p38-MAPK) negatively regulates the Ang II-induced NHE1 activation in vascular smooth muscle and the positive inotropic effect of ET in the heart, we hypothesized that this kinase might modulate the magnitude of the SFR to stretch. METHODS: Experiments were performed in isolated rat papillary muscles subjected to sudden stretch from 92 to 98% of its maximal length, in the absence or presence of the p38-MAPK inhibitor SB202190, or its inactive analogous SB202474. Western blot technique was used to determine phosphorylation level of p38-MAPK, ERK1/2, p90RSK and NHE-1 (previously immunoprecipitated with NHE-1 polyclonal antibody). Dual specificity phosphatase 6 (DUSP6) expression was evaluated by RT-PCR and western blot. Additionally, the Na⁺-dependent intracellular pH recovery from an ammonium prepulse-induced acid load was used to asses NHE-1 activity. RESULTS: The SFR was larger under p38-MAPK inhibition (SB202190), effect that was not observed in the presence of an inactive analogous (SB202474). Myocardial stretch activated p38-MAPK, while pre-treatment with SB202190 precluded this effect. Inhibition of p38-MAPK increased stretched-induced NHE-1 phosphorylation and activity, key event in the SFR development. Consistently, p38-MAPK inhibition promoted a greater increase in ERK1/2-p90RSK phosphorylation/activation after myocardial stretch, effect that may certainly be responsible for the observed increase in NHE-1 phosphorylation under this condition. Myocardial stretch induced up-regulation of the DUSP6, which specifically dephosphorylates ERK1/2, effect that was blunted by SB202190. CONCLUSION: Taken together, our data support the notion that p38-MAPK activation after myocardial stretch restricts the SFR by limiting ERK1/2-p90RSK phosphorylation, and consequently NHE-1 phosphorylation/activity, through a mechanism that involves DUSP6 up-regulation.