Scalable protein production by Komagataella phaffii enabled by ARS plasmids and carbon source-based selection.

BACKGROUND: Most recombinant Komagataella phaffii (Pichia pastoris) strains for protein production are generated by genomic integration of expression cassettes. The clonal variability in gene copy numbers, integration loci and consequently product titers limit the aptitude for high throughput applications in drug discovery, enzyme engineering or most comparative analyses of genetic elements such as promoters or secretion signals. Circular episomal plasmids with an autonomously replicating sequence (ARS), an alternative which would alleviate some of these limitations, are inherently unstable in K. phaffii. Permanent selection pressure, mostly enabled by antibiotic resistance or auxotrophy markers, is crucial for plasmid maintenance and hardly scalable for production. The establishment and use of extrachromosomal ARS plasmids with key genes of the glycerol metabolism (glycerol kinase 1, GUT1, and triosephosphate isomerase 1, TPI1) as selection markers was investigated to obtain a system with high transformation rates that can be directly used for scalable production processes in lab scale bioreactors. RESULTS: In micro-scale deep-well plate experiments, ARS plasmids employing the Ashbya gossypii TEF1 (transcription elongation factor 1) promoter to regulate transcription of the marker gene were found to deliver high transformation efficiencies and the best performances with the reporter protein (CalB, lipase B of Candida antarctica) for both, the GUT1- and TPI1-based, marker systems. The GUT1 marker-bearing strain surpassed the reference strain with integrated expression cassette by 46% upon re-evaluation in shake flask cultures regarding CalB production, while the TPI1 system was slightly less productive compared to the control. In 5 L bioreactor methanol-free fed-batch cultivations, the episomal production system employing the GUT1 marker led to 100% increased CalB activity in the culture supernatant compared to integration construct. CONCLUSIONS: For the first time, a scalable and methanol-independent expression system for recombinant protein production for K. phaffii using episomal expression vectors was demonstrated. Expression of the GUT1 selection marker gene of the new ARS plasmids was refined by employing the TEF1 promoter of A. gossypii. Additionally, the antibiotic-free marker toolbox for K. phaffii was expanded by the TPI1 marker system, which proved to be similarly suited for the use in episomal plasmids as well as integrative expression constructs for the purpose of recombinant protein production.

Efecto del suero aislado de pacientes con infarto agudo de miocardio con elevación del segmento ST en las células endoteliales / Effect of serum from patients with ST-segment elevation myocardial infarction on endothelial cells

Introducción y objetivos La reperfusión coronaria produce un daño en la microcirculación y, en concreto, las células endoteliales. Este estudio evalúa el efecto del suero aislado tras la revascularización de pacientes con un infarto agudo de miocardio con elevación del segmento ST (IAMCEST) en la viabilidad celular, el grado de permeabilidad endotelial in vitro y la asociación de estos parámetros con una mayor extensión de los índices de resonancia magnética cardiaca (RMC) relacionados con el daño por reperfusión (edema, hemorragia y obstrucción microvascular). Métodos Se incubaron células endoteliales de arteria coronaria humana con suero aislado 24 h tras la revascularización de 43 pacientes con IAMCEST evaluados mediante RMC y 14 sujetos de control. Se testó el efecto del suero de pacientes con IAMCEST en la pérdida de viabilidad celular por activación de la apoptosis y la necrosis, así como en la permeabilidad y la estructura de la monocapa endotelial. Resultados El suero de pacientes con IAMCEST aumentó la apoptosis (p <0,01) y la necrosis (p <0,05) de células endoteliales de arteria coronaria humana y causó un incremento de la permeabilidad de la monocapa endotelial in vitro (p <0,01) debido a mayores espacios intercelulares (p <0,05 frente a los controles). Una mayor necrosis inducida por suero se asoció con más permeabilidad endotelial in vitro (p <0,05) y con una mayor extensión de los principales índices de daño tras reperfusión y mayor tamaño de infarto. Conclusiones El suero tras la reperfusión de pacientes con IAMCEST induce la apoptosis y la necrosis in vitro de las células endoteliales y la permeabilidad endotelial. Cuanto más potente sea el efecto inductor de necrosis, más deletéreas son las consecuencias en cuanto al daño estructural resultante. (AU)

Introduction and objectives Clinical and experimental studies have shown that, in patients with reperfused ST-segment elevation myocardial infarction (STEMI), abnormalities in the endothelial monolayer are initiated during ischemia but rapidly intensify upon restoration of blood perfusion to the ischemic area. We aimed to evaluate the effect of serum isolated after revascularization from STEMI patients on the degree of endothelial permeability in vitro, by promoting endothelial cell apoptosis and necrosis in vitro. We also investigated the association between the percentage of serum-induced endothelial cell apoptosis or necrosis in vitro and the extent of cardiovascular magnetic resonance (CMR)-derived parameters of reperfusion injury (edema, hemorrhage, and microvascular obstruction). Methods Human coronary artery endothelial cells were incubated with serum isolated 24hours after revascularization from 43 STEMI patients who underwent CMR and 14 control participants. We assessed the effect of STEMI serum on activation of apoptosis and necrosis, as well as on the permeability and structure of the endothelial monolayer. Results Serum from STEMI patients increased apoptosis (P <.01) and necrosis (P <.05) in human coronary artery endothelial cells and caused increased permeability of the endothelial monolayer in vitro (P <.01), due to enlarged intercellular spaces (P <.05 vs control in all cases). Higher serum-induced necrosis was associated with greater endothelial permeability in vitro (P <.05) and with more extensive CMR-derived indices of reperfusion injury and infarct size. Conclusions Postreperfusion serum activates necrosis and apoptosis in endothelial cells and increases the degree of endothelial permeability in vitro. The more potent the necrosis-triggering effect of serum, the more deleterious the consequences in terms of the resulting cardiac structure. (AU)

Synergic kinetic and physiological control to improve the efficiency of Komagataella phaffii recombinant protein production bioprocesses.

The yeast Komagataella phaffii (Pichia pastoris) is currently considered a versatile and highly efficient host for recombinant protein production (RPP). Interestingly, the regulated application of specific stress factors as part of bioprocess engineering strategies has proven potential for increasing the production of recombinant products. This study aims to evaluate the impact of controlled oxygen-limiting conditions on the performance of K. phaffii bioprocesses for RPP in combination with the specific growth rate (µ) in fed-batch cultivations. In this work, Candida rugosa lipase 1 (Crl1) production, regulated by the constitutive GAP promoter, growing at different nominal µ (0.030, 0.065, 0.100 and 0.120 h-1 ) under both normoxic and hypoxic conditions in carbon-limiting fed-batch cultures is analysed. Hypoxic fermentations were controlled at a target respiratory quotient (RQ) of 1.4, with excellent performance, using an innovative automated control based on the stirring rate as the manipulated variable developed during this study. The results conclude that oxygen limitation positively affects bioprocess efficiency under all growing conditions compared. The shift from respiratory to respiro-fermentative metabolism increases bioprocess productivity by up to twofold for the specific growth rates evaluated. Moreover, the specific product generation rate (qp ) increases linearly with µ, regardless of oxygen availability. Furthermore, this hypoxic boosting effect was also observed in the production of Candida antarctica lipase B (CalB) and pro-Rhizopus oryzae lipase (proRol), thus proving the synergic effect of kinetic and physiological stress control. Finally, the Crl1 production scale-up was conducted successfully, confirming the strategy's scalability and the robustness of the results obtained at the bench-scale level.

Effect of serum from patients with ST-segment elevation myocardial infarction on endothelial cells.

INTRODUCTION AND OBJECTIVES: Clinical and experimental studies have shown that, in patients with reperfused ST-segment elevation myocardial infarction (STEMI), abnormalities in the endothelial monolayer are initiated during ischemia but rapidly intensify upon restoration of blood perfusion to the ischemic area. We aimed to evaluate the effect of serum isolated after revascularization from STEMI patients on the degree of endothelial permeability in vitro, by promoting endothelial cell apoptosis and necrosis in vitro. We also investigated the association between the percentage of serum-induced endothelial cell apoptosis or necrosis in vitro and the extent of cardiovascular magnetic resonance (CMR)-derived parameters of reperfusion injury (edema, hemorrhage, and microvascular obstruction). METHODS: Human coronary artery endothelial cells were incubated with serum isolated 24hours after revascularization from 43 STEMI patients who underwent CMR and 14 control participants. We assessed the effect of STEMI serum on activation of apoptosis and necrosis, as well as on the permeability and structure of the endothelial monolayer. RESULTS: Serum from STEMI patients increased apoptosis (P <.01) and necrosis (P <.05) in human coronary artery endothelial cells and caused increased permeability of the endothelial monolayer in vitro (P <.01), due to enlarged intercellular spaces (P <.05 vs control in all cases). Higher serum-induced necrosis was associated with greater endothelial permeability in vitro (P <.05) and with more extensive CMR-derived indices of reperfusion injury and infarct size. CONCLUSIONS: Postreperfusion serum activates necrosis and apoptosis in endothelial cells and increases the degree of endothelial permeability in vitro. The more potent the necrosis-triggering effect of serum, the more deleterious the consequences in terms of the resulting cardiac structure.

Prevention of tobacco use in an adolescent population through a multi-personal intervention model.

INTRODUCTION: The study aimed to assess the impact of a new intervention proposal involving students, teachers, and parents on smoking prevalence in secondary school adolescents. METHODS: A quasi-experimental study was conducted, in which the response to a preventive multi-personal intervention model (intervention) against tobacco consumption was compared with a standard anti-smoking activity carried out by the local government administration (control). The study was carried out during the 2017-2018 academic year. The study population included 306 students (intervention 151, control 155) with a mean age of 13.4 years. The model involved the parents, the students (aged 15-17 years), and the teachers. The primary outcome was the change in smoking status one year after the intervention. RESULTS: The percentage of non-smokers increased from 84.1% to 88.7% in the intervention group and remained almost unchanged among controls (89.3% vs 89.9%). After one year, there was an increase in the prevalence of non-smokers of 4.6% and a decrease in the prevalence of smokers of 4.7% among students who received the multi-personal intervention, whereas changes among controls were almost negligible (there was in fact a slight increase in the prevalence of smokers of 0.9%). The students who received the intervention smoked less or quit smoking more than those in the control group (OR=0.135; 95% CI: 0.019-0.973, p=0.047). CONCLUSIONS: The multi-personal model developed in the study with the participation of teachers and parents focused on students was feasible, and effectively reduced the prevalence of smoking among high school adolescents.

Cancer Patients' Satisfaction with In-Home Palliative Care and Its Impact on Disease Symptoms.

The aim of the study was to determine whether the satisfaction of cancer patients with in-home palliative care is associated with the impact of disease symptoms and with self-perceived quality of life. This was a cross-sectional descriptive study, conducted in the primary health care sector in six clinical management units, where 72 patients were recruited over a period of six months. The severity of symptoms was determined by the Edmonton Symptom Assessment System (ESAS). Quality of life was evaluated with the EORTC QLQ-C30 (version 3) questionnaire, and patients' satisfaction with the care received was evaluated by the Client Satisfaction Questionnaire (CSQ-8). The patients' satisfaction with the health care received was represented by an average score of 6, on a scale of 1-10; thus, there is room for improvement in patient satisfaction. Moreover, it was found that more intense symptoms and lower quality of life are associated with lower satisfaction with health care received (p = 0.001). Similarly, when symptoms are more severe, the quality of life is lower (p < 0.001). The identification of fatigue, reduced well-being, pain, drowsiness, and depression as the symptoms experienced with the highest intensity by our patients provides valuable information for health care providers in developing individualized symptom management plans for patients with advanced cancer.

Characteristics of tobacco use among secondary school students: a cross-sectional study in a school in Valencia, Spain.

Introduction: Cigarette smoking is a significant public health problem, and it is essential to work actively with young people to limit the incorporation of this addiction. This study aimed to identify characteristics associated with tobacco use in adolescents in a real setting. Methods: Epidemiologic, cross-sectional study including secondary school students aged 12-17 years in the 1st, 2nd, and 3rd grades of "Joan Fuster High School" in the city of Sueca, Valencia (Spain). An anonymous, self-administered questionnaire was used to collect data on demographics, cigarette smoking history, alcohol consumption, nicotine dependence, and exposure to parental cigarette smoking. Results: The final sample of individuals surveyed included 306 students (50.6% females) with a median age of 13 years. The prevalence of cigarette smoking was 11.8% (13.5% in females and 9.9% in males). The mean age of cigarette smoking onset was 12.7 ± 1.6 years. Ninety-three students (30.4%) were repeaters, and 114 (37.3%) reported alcohol consumption. Significant factors associated with tobacco use were being a repeater (odds ratio [OR] 4.19, 95% confidence interval [CI] 1.75-10.55, p = 0.002), alcohol consumption (OR 4.06, 95% CI 1.75-10.15, p = 0.002) and parental cigarette smoking (OR 3.76, 95% CI 1.52-10.74, p = 0.007). Discussion: An operational profile of features associated with tobacco consumption was identified in the presence of parental cigarette smoking, alcohol consumption, and poor academic performance. Consideration of these factors could be useful in the operational design of cigarette smoking cessation interventions for young people in a context where there is a great need for better prevention and control of cigarette smoking.

Enabling growth-decoupled Komagataella phaffii recombinant protein production based on the methanol-free PDH promoter.

The current transition towards the circular bioeconomy requires a rational development of biorefineries to sustainably fulfill the present demands. The use of Komagataella phaffii (Pichia pastoris) can meet this challenge, since it has the capability to use crude glycerol as a carbon-source, a by-product from the biodiesel industry, while producing high- and low-added value products. Recombinant protein production (RPP) using K. phaffii has often been driven either by the methanol induced AOX1 promoter (P AOX1 ) and/or the constitutive GAP promoter (P GAP ). In the last years, strong efforts have been focused on developing novel expression systems that expand the toolbox variety of K. phaffii to efficiently produce diverse proteins that requires different strategies. In this work, a study was conducted towards the development of methanol-free expression system based on a heat-shock gene promoter (PDH) using glycerol as sole carbon source. Using this promoter, the recombinant expression is strongly induced in carbon-starving conditions. The classical P GAP was used as a benchmark, taking for both strains the lipase B from Candida antarctica (CalB) as model protein. Titer of CalB expressed under PDH outperformed P GAP controlled expression in shake-flask cultivations when using a slow-release continuous feeding technology, confirming that PDH is induced under pseudo-starving conditions. This increase was also confirmed in fed-batch cultivations. Several optimization rounds were carried out for PDH under different feeding and osmolarity conditions. In all of them the PDH controlled process outperformed the P GAP one in regard to CalB titer. The best PDH approach reached 3.6-fold more specific productivity than P GAP fed-batch at low µ. Compared to the optimum approach for P GAP -based process, the best PDH fed-batch strategy resulted in 2.3-fold higher titer, while the specific productivity was very similar. To summarize, PDH is an inducible promoter that exhibited a non-coupled growth regulation showing high performance, which provides a methanol-free additional solution to the usual growth-coupled systems for RPP. Thus, this novel system emerges as a potential alternative for K. phaffii RPP bioprocess and for revaluing crude glycerol, promoting the transition towards a circular economy.

Effect of Self-Chosen Music in Alleviating the Burden on Family Caregivers of Patients with Advanced Cancer: A Randomised Controlled Trial.

The experience of caregiver burden among family members of patients with advanced cancer is a common problem. The aim of this study was to determine whether the burden may be alleviated by means of a therapeutic approach based on self-chosen music. This randomised controlled trial (ClinicalTrials.gov, NCT04052074. Registered 9 August 2019) included 82 family caregivers of patients receiving home palliative care for advanced cancer. The intervention group (n = 41) listened to pre-recorded, self-chosen music for 30 min/day for seven consecutive days, while the control group (n = 41) listened to a recording of basic therapeutic education at the same frequency. The degree of burden was assessed by the Caregiver Strain Index (CSI), calculated before and after the seven-day intervention. According to this measure, caregiver burden fell significantly in the intervention group (CSI change: -0.56, SD 2.16) but increased in the control group (CSI change: +0.68, SD 1.47), with a significant group x moment interaction F(1, 80) = 9.30, p = 0.003, η2p = 0.11. These results suggest that, in the short term at least, the use of therapy based on self-chosen music alleviates the burden on family caregivers of palliative cancer patients. Moreover, this therapy is easy to administer at home and does not present any problems in practice.

CPV of the Future: AI-Powered Continued Process Verification for Bioreactor Processes.

According to the standard guidelines by the FDA, process validation in biopharma manufacturing encompasses a life cycle consisting of three stages: process design (PD), process qualification (PQ), and continued process verification (CPV). The validity and efficiency of the analytics methods employed during the CPV require extensive knowledge of the process. However, for new processes and new drugs, such knowledge is often not available from Process performance qualification and Validation (PPQV). In this work, the suitability of methods based on machine learning/artificial intelligence (ML/AI) for the CPV applied in bioprocess monitoring and cell physiological control of the yeast Pichia pastoris (Komagataella phaffii) was studied with limited historical data. In particular, the production of recombinant Candida rugosa lipase 1 (Crl1) under hypoxic conditions in fed-batch cultures was considered as a case study. Supervised and unsupervised machine learning models using data from fed-batch bioprocesses with different gene dosage clones under normoxic and hypoxic conditions were evaluated. Firstly, a multivariate anomaly detection (isolation forest) model was applied to the batch phase of the bioprocess. Secondly, a supervised random forest model for prediction of required operator's control actions during the semiautomated fed-batch phase under hypoxic conditions was assessed to maintain the respiratory quotient (RQ) within the desired range for maximizing the specific production rate (qP ). The performance of these models was tested on historical data using independent evaluation of the process by the process control engineer (subject matter expert-SME), and on real-time data in the case of manual action prediction, where the model was implemented to guide the control of the bioprocess. The work presented here constitutes a proof-of-concept that multivariate analytics methods, based on machine learning, can be a valuable tool for real-time monitoring and control of biopharma manufacturing bioprocesses to improve its efficiency and to assure product quality.

The influence of symptom severity of palliative care patients on their family caregivers.

BACKGROUND: This study anlyzed whether family caregivers of patients with advanced cancer suffer impaired sleep quality, increased strain, reduced quality of life or increased care burden due to the presence and heightened intensity of symptoms in the person being cared for. METHOD: A total of 41 patient-caregiver dyads (41 caregivers and 41 patients with advanced cancer) were recruited at six primary care centres in this cross-sectional study. Data were obtained over a seven-month period. Caregiver's quality of sleep (Pittsburgh Sleep Quality Index), caregiver's quality of life (Quality of Life Family Version), caregiver strain (Caregiver Strain Index), patients' symptoms and their intensity (Edmonton Symptom Assessment System), and sociodemographic, clinical and care-related data variables were assessed. The associations were determined using non-parametric Spearman correlation. RESULTS: Total Edmonton Symptom Assessment System was significantly related to overall score of the Pittsburgh Sleep Quality Index (r = 0.365, p = 0.028), the Caregiver Strain Index (r = 0.45, p = 0.005) and total Quality of Life Family Version (r = 0.432, p = 0.009), but not to the duration of daily care (r = -0.152, p = 0.377). CONCLUSIONS: Family caregivers for patients with advanced cancer suffer negative consequences from the presence and intensity of these patients' symptoms. Therefore, optimising the control of symptoms would benefit not only the patients but also their caregivers. Thus, interventions should be designed to improve the outcomes of patient-caregiver dyads in such cases.

Innovative Bioprocess Strategies Combining Physiological Control and Strain Engineering of Pichia pastoris to Improve Recombinant Protein Production.

The combination of strain and bioprocess engineering strategies should be considered to obtain the highest levels of recombinant protein production (RPP) while assuring product quality and process reproducibility of heterologous products. In this work, two complementary approaches were investigated to improve bioprocess efficiency based on the yeast P. pastoris. Firstly, the performance of two Candida rugosa lipase 1 producer clones with different gene dosage under the regulation of the constitutive P GAP were compared in chemostat cultures with different oxygen-limiting conditions. Secondly, hypoxic conditions in carbon-limited fed-batch cultures were applied by means of a physiological control based on the respiratory quotient (RQ). Stirring rate was selected to maintain RQ between 1.4 and 1.6, since it was found to be the most favorable in chemostat. As the major outcome, between 2-fold and 4-fold higher specific production rate (q P ) values were observed when comparing multicopy clone (MCC) and single-copy clone (SCC), both in chemostat and fed-batch. Additionally, when applying oxygen limitation, between 1.5-fold and 3-fold higher q P values were obtained compared with normoxic conditions. Thus, notable increases of up to 9-fold in the production rates were reached. Furthermore, transcriptional analysis of certain key genes related to RPP and central carbon metabolism were performed. Results seem to indicate the presence of a limitation in post-transcriptional protein processing steps and a possible transcription attenuation of the target gene in the strains with high gene dosage. The entire approach, including both strain and bioprocess engineering, represents a relevant novelty involving physiological control in Pichia cell factory and is of crucial interest in bioprocess optimization, boosting RPP, allowing bioproducts to be economically competitive in the market, and helping develop the bioeconomy.

Tabaquismo en pacientes hospitalizados. Una gran oportunidad / Smoking in hospitalized patients. A great opportunity

El objetivo de este estudio es conocer las características de los fumadores ingresados en diferentes servicios médicos y quirúrgicos en un hospital universitario y la percepción de los pacientes respecto a la necesidad de una intervención especializada. La muestra comprende un total de 307 pacientes (edad media de 59,4 años), siendo un 40% (n = 123) no fumadores, 42,7% (n = 131) exfumadores, y un 17,3% (n = 53) fumadores. El consumo medio de los fumadores era de 22,2 cigarrillos/día y la gravedad de la dependencia a la nicotina evaluado con el test de Fagerström sobrepasaba los 5 puntos en más de la mitad de la muestra. Por otra parte, el 77,7% había realizado al menos un intento previo de abandono del consumo de tabaco. Casi la totalidad de la muestra (89,9%) de los fumadores y ex fumadores consideraba necesario desarrollar programas de tratamiento del tabaquismo en la hospitalización. Finalmente se argumenta la importancia del contexto hospitalario como oportunidad para abordar la cesación del hábito tabáquico. Los datos obtenidos en el presente estudio permitirán enfocar más adecuadamente el manejo de estos pacientes y optimizar los recursos.(AU)

The objective of this study is to describe the characteristics of smokers admitted to different medical and surgical services in a university hospital and the perception of patients regarding the need for a specialized intervention. The sample comprises a total of 307 patients (mean age of 59.4 years), being 40% (n = 123) nonsmokers, 42.7% (n = 131) ex-smokers, and 17.3% (n = 53) smokers. The average consumption of smokers was 22.2 cigarettes / day and the severity of nicotine dependence evaluated with the Fagerström test exceeded 5 points in more than half of the sample. On the other hand, 77.7% had made at least one previous attempt to quit tobacco use. Almost the entire sample (89.9%) of smokers and ex-smokers considered it necessary to develop tobacco treatment programs during hospitalization. Finally, the importance of the hospital context is argued as an opportunity to address the cessation of smoking. The data obtained in this study will allow focusing more appropriately on the management of these patients and optimizing resources.(AU)

Smoking in hospitalized patients. A great opportunity. / Tabaquismo en pacientes hospitalizados. Una gran oportunidad.

The objective of this study is to describe the characteristics of smokers admitted to different medical and surgical services in a university hospital and the perception of patients regarding the need for a specialized intervention. The sample comprises a total of 307 patients (mean age of 59.4 years), being 40% (n = 123) non-smokers, 42.7% (n = 131) ex-smokers, and 17.3% (n = 53) smokers. The average consumption of smokers was 22.2 cigarettes / day and the severity of nicotine dependence evaluated with the Fagerström test exceeded 5 points in more than half of the sample. On the other hand, 77.7% had made at least one previous attempt to quit tobacco use. Almost the entire sample (89.9%) of smokers and ex-smokers considered it necessary to develop tobacco treatment programs during hospitalization. Finally, the importance of the hospital context is argued as an opportunity to address the cessation of smoking. The data obtained in this study will allow focusing more appropriately on the management of these patients and optimizing resources.

El objetivo de este estudio es conocer las características de los fumadores ingresados en diferentes servicios médicos y quirúrgicos en un hospital universitario y la percepción de los pacientes respecto a la necesidad de una intervención especializada. La muestra comprende un total de 307 pacientes (edad media de 59,4 años), siendo un 40% (n = 123) no fumadores, 42,7% (n = 131) exfumadores, y un 17,3% (n = 53) fumadores. El consumo medio de los fumadores era de 22,2 cigarrillos/día y la gravedad de la dependencia a la nicotina evaluado con el test de Fagerström sobrepasaba los 5 puntos en más de la mitad de la muestra. Por otra parte, el 77,7% había realizado al menos un intento previo de abandono del consumo de tabaco. Casi la totalidad de la muestra (89,9%) de los fumadores y ex fumadores consideraba necesario desarrollar programas de tratamiento del tabaquismo en la hospitalización. Finalmente se argumenta la importancia del contexto hospitalario como oportunidad para abordar la cesación del hábito tabáquico. Los datos obtenidos en el presente estudio permitirán enfocar más adecuadamente el manejo de estos pacientes y optimizar los recursos.

Second- and third-generation biodiesel production with immobilised recombinant Rhizopus oryzae lipase: Influence of the support, substrate acidity and bioprocess scale-up.

Rhizopus oryzae lipase immobilised onto differently functionalised polymethacrylate (Purolite®) and magnetite superparamagnetic supports was assessed as a catalyst for biodiesel production with pomace oil. The presence of surface hydrocarbon chains increased the operational stability of the biocatalysts supported on Purolite® and superparamagnetic particles up to 9 and 2 times, respectively. By contrast, the presence of functional groups had no effect on the initial transesterification rate, which was twice higher with the lipase immobilised onto Purolite®. Also, functionalising Purolite® with epoxide and octadecyl groups led to the highest biodiesel and volumetric productivity. This biocatalyst with other substrates including makauba, jatropha, waste cooking oil, and microbial oil, led to similar initial reaction rates. However, simply raising substrate acidity from 0.5 to 2% increased the operational stability of the biocatalysts 15 times. A synergistic effect between acyl-acceptor concentration and substrate acidity was observed. The transesterification reaction was successfully scaled up to 50 mL.

Scalable production and application of Pichia pastoris whole cell catalysts expressing human cytochrome P450 2C9.

BACKGROUND: Currently, the numerous and versatile applications in pharmaceutical and chemical industry make the recombinant production of cytochrome P450 enzymes (CYPs) of great biotechnological interest. Accelerating the drug development process by simple, quick and scalable access of human drug metabolites is key for efficient and targeted drug development in response to new and sometimes unexpected medical challenges and needs. However, due its biochemical complexity, scalable human CYP (hCYP) production and their application in preparative biotransformations was still in its infancy. RESULTS: A scalable bioprocess for fine-tuned co-expression of hCYP2C9 and its essential complementary human cytochrome P450 reductase (hCPR) in the yeast Pichia pastoris (Komagataella phaffii) is presented. High-throughput screening (HTS) of a transformant library employing a set of diverse bidirectional expression systems with different regulation patterns and a fluorimetric assay was used in order to fine-tune hCYP2C9 and hCPR co-expression, and to identify best expressing clonal variants. The bioprocess development for scalable and reliable whole cell biocatalyst production in bioreactors was carried out based on rational optimization criteria. Among the different alternatives studied, a glycerol carbon-limiting strategy at high µ showed highest production rates, while methanol co-addition together with a decrease of µ provided the best results in terms of product to biomass yield and whole cell activity. By implementing the mentioned strategies, up to threefold increases in terms of production rates and/or yield could be achieved in comparison with initial tests. Finally, the performance of the whole cell catalysts was demonstrated successfully in biotransformation using ibuprofen as substrate, demonstrating the expected high selectivity of the human enzyme catalyst for 3'hydroxyibuprofen. CONCLUSIONS: For the first time a scalable bioprocess for the production of hCYP2C9 whole cell catalysts was successfully designed and implemented in bioreactor cultures, and as well, further tested in a preparative-scale biotransformation of interest. The catalyst engineering procedure demonstrated the efficiency of the employment of a set of differently regulated bidirectional promoters to identify transformants with most effective membrane-bound hCYP/hCPR co-expression ratios and implies to become a model case for the generation of other P. pastoris based catalysts relying on co-expressed enzymes such as other P450 catalysts or enzymes relying on co-expressed enzymes for co-factor regeneration.

Bioprocess performance analysis of novel methanol-independent promoters for recombinant protein production with Pichia pastoris.

BACKGROUND: Pichia pastoris is a powerful and broadly used host for recombinant protein production (RPP), where past bioprocess performance has often been directed with the methanol regulated AOX1 promoter (PAOX1), and the constitutive GAP promoter (PGAP). Since promoters play a crucial role in an expression system and the bioprocess efficiency, innovative alternatives are constantly developed and implemented. Here, a thorough comparative kinetic characterization of two expression systems based on the commercial PDF and UPP promoters (PPDF, PUPP) was first conducted in chemostat cultures. Most promising conditions were subsequently tested in fed-batch cultivations. These new alternatives were compared with the classical strong promoter PGAP, using the Candida antarctica lipase B (CalB) as model protein for expression system performance. RESULTS: Both the PPDF and PUPP-based expression systems outperformed similar PGAP-based expression in chemostat cultivations, reaching ninefold higher specific production rates (qp). CALB transcription levels were drastically higher when employing the novel expression systems. This higher expression was also correlated with a marked upregulation of unfolded protein response (UPR) related genes, likely from an increased protein burden in the endoplasmic reticulum (ER). Based on the chemostat results obtained, best culture strategies for both PPDF and PUPP expression systems were also successfully implemented in 15 L fed-batch cultivations where qp and product to biomass yield (YP/X*) values were similar than those obtained in chemostat cultivations. CONCLUSIONS: As an outcome of the macrokinetic characterization presented, the novel PPDF and PUPP were observed to offer much higher efficiency for CalB production than the widely used PGAP-based methanol-free alternative. Thus, both systems arise as highly productive alternatives for P. pastoris-based RPP bioprocesses. Furthermore, the different expression regulation patterns observed indicate the level of gene expression can be adjusted, or tuned, which is interesting when using Pichia pastoris as a cell factory for different products of interest.

Predictors of sleep disturbances in caregivers of patients with advanced cancer receiving home palliative care: A descriptive cross-sectional study.

PURPOSE: To evaluate the quality of sleep in caregivers of patients with advanced cancer receiving home palliative care, basing the analysis on subjective and objective measures, and to develop a predictive model of sleep disturbances among this population. METHOD: A descriptive cross-sectional study was conducted in six clinical management units within primary healthcare centres. Data were obtained during a period of six months, from a sample population of 41 caregivers. The Pittsburgh Sleep Quality Index (PSQI) and a 7-day accelerometry evaluation were performed to assess sleep quality. Daytime sleepiness, caregiver strain and quality of life were also evaluated. RESULTS: According to the PSQI, 90.2% of participants had poor sleep quality. The average duration of night-time sleep, measured by accelerometry and the PSQI, was 6 h. Taking PSQI as the dependent variable, the study model predicted 40.7% of the variability (p < 0.01). The variables "Caregiver strain" and "Daily hours dedicated to care" produced the following results: B coefficient 0.645; p = 0.001; and B coefficient 0.230; p = 0.010, respectively. CONCLUSIONS: The caregivers presented significant health-related alterations, including sleep disturbances, which were directly related to two variables: the index of caregiver strain and the number of hours per day dedicated to providing care.