CRISPR/Cas9-Mediated Disruption of the pcz1 Gene and Its Impact on Growth, Development, and Penicillin Production in Penicillium rubens.

Penicillium rubens is a filamentous fungus of great biotechnological importance due to its role as an industrial producer of the antibiotic penicillin. However, despite its significance, our understanding of the regulatory mechanisms governing biological processes in this fungus is still limited. In fungi, zinc finger proteins containing a Zn(II)2Cys6 domain are particularly interesting regulators. Although the P. rubens genome harbors many genes encoding proteins with this domain, only two of them have been investigated thus far. In this study, we employed CRISPR-Cas9 technology to disrupt the pcz1 gene, which encodes a Zn(II)2Cys6 protein in P. rubens. The disruption of pcz1 resulted in a decrease in the production of penicillin in P. rubens. This decrease in penicillin production was accompanied by the downregulation of the expression of pcbAB, pcbC and penDE genes, which form the biosynthetic gene cluster responsible for penicillin production. Moreover, the disruption of pcz1 also impacts on asexual development, leading to decreased growth and conidiation, as well as enhanced conidial germination. Collectively, our results indicate that pcz1 acts as a positive regulator of penicillin production, growth, and conidiation, while functioning as a negative regulator of conidial germination in P. rubens. To the best of our knowledge, this is the first report involving a gene encoding a Zn(II)2Cys6 protein in the regulation of penicillin biosynthesis in P. rubens.

Interferon-Alpha Decreases Cancer Stem Cell Properties and Modulates Exosomes in Malignant Melanoma.

Malignant melanoma (MM) can spread to other organs and is resistant in part due to the presence of cancer stem cell subpopulations (CSCs). While a controversial high dose of interferon-alpha (IFN-α) has been used to treat non-metastatic high-risk melanoma, it comes with undesirable side effects. In this study, we evaluated the effect of low and high doses of IFN-α on CSCs by analyzing ALDH activity, side population and specific surface markers in established and patient-derived primary cell lines. We also assessed the clonogenicity, migration and tumor initiation capacities of IFN-α treated CSCs. Additionally, we investigated genomic modulations related to stemness properties using microRNA sequencing and microarrays. The effect of IFN-α on CSCs-derived exosomes was also analyzed using NanoSight and liquid chromatography (LC-HRMS)-based metabolomic analysis, among others. Our results showed that even low doses of IFN-α reduced CSC formation and stemness properties, and led to a significant decrease in the ability to form tumors in mice xenotransplants. IFN-α also modulated the expression of genes and microRNAs involved in several cancer processes and metabolomics of released exosomes. Our work suggests the utility of low doses of interferon, combined with the analysis of metabolic biomarkers, as a potential clinical approach against the aggressiveness of CSCs in melanoma.

[Dietary and physical activity practices and preferences in children: An approach from school parliaments in educational public establishments]. / Prácticas y preferencias alimentarias y de actividad física en niños y niñas: Una aproximación desde los Parlamentos Escolares en establecimientos educacionales.

In Chile, overnutrition continues to increase, especially affecting children. Solving this public health problem requires the development of promotion and prevention strategies that consider the suggestions of the communities, especially those of the children themselves. OBJECTIVE: To know the opinions and suggestions of third and fourth-grade children from schools in the southern area of Santiago, Chile, regarding their eating practices and physical activity, as part of the FONDEF IT 1810016 project. SUBJECTS AND METHOD: Seven School Meetings were held in seven schools using a participatory qualitative methodology, collecting the opinions of 176 children regarding both their food and physical activity habits and preferences. RESULTS: The most consumed and preferred foods are those easy to prepare and highly available, such as bread, pasta, and milk. Foods that require preparation or are less available, such as fish, legumes, fruits, vegetables, and homemade preparations, are less consumed and have less preference. Regarding physical activities, video games and soccer stand out. Students propose increasing the hours of physical education and recesses and improving the availability and access to healthy foods in school environments as a solution strategy. CONCLUSIONS: School Meetings as a participatory strategy contribute to the joint generation of knowledge. The need to include communities as participants in health initiatives recognizes, through their role, children as subjects of rights.

Continuous administration of leuprolide acetate improves urinary function in male rats with severe thoracic spinal cord injury.

AIMS: To determine if a continuous administration of leuprolide acetate (LA), a synthetic agonist for the gonadotrophin-releasing hormone receptor, facilitates the recovery of urinary function in spinal cord injured male rats. MAIN METHODS: Male Wistar rats were randomized into spinal cord injury (SCI; n = 7), SCI with continuous administration of LA for two weeks via implantation of a subcutaneous osmotic pump (SCI + LA; n = 7), Sham SCI (SH-SCI; n = 6) or no surgery (Intact; n = 6) groups. Micturition, hind-limb nociception and locomotor behaviors were analyzed before and after surgical procedures on days 7, 14, 21 and 28. After behavioral studies, electromyography of the external urethral sphincter (EUS-EMG) and cystometric (CMG) studies were performed in all groups. KEY FINDINGS: SCI significantly decreased frequency of voids and CMG parameters (p < 0.001), abolished the bursting activity of the EUS during CMG, significantly increased hind limb sensory threshold and decreased locomotor performance in comparison to the other groups (p < 0.001). Continuous LA treatment significantly increased the frequency of voids and improved CMG parameters (p < 0.001), exhibiting bursting EUS activity during CMGs, and enhanced locomotor performance in comparison to SCI rats (p < 0.001). SIGNIFICANCE: SCI severely affected behavioral and functional micturition processes, including sensory and locomotor functions. Systemic and uninterrupted treatment with LA improves the recovery of micturition behavior and the synergistic function of the EUS. Furthermore, sensory and locomotor responses were also improved in SCI rats. This procedure may have a therapeutic potential to facilitate urinary function recovery in patients with SCI.

Food Availability in Different Food Environments Surrounding Schools in a Vulnerable Urban Area of Santiago, Chile: Exploring Socioeconomic Determinants.

The analysis of the food environment is used to identify areas with gaps in the availability of healthy foods and can be used as a public policy assessment tool. In recent decades, Chile has implemented several strategies and regulations to improve food environments, with encouraging results. Little is known about the scope of these measures in socially vulnerable environments. This study is part of a project that seeks to build an integrated intervention model for healthy school environments in a vulnerable area of Santiago, Chile. The objective of this study was to evaluate the availability of healthy and unhealthy foods around schools and the relationship between it and socioeconomic determinants of the school community in the Chilean context. A cross-sectional study to measure the food environment of informal markets (street food), formal markets (stores), and institutions (schools) was conducted in and around 12 schools (100 m surrounding schools) in a vulnerable urban area of Santiago, Chile. A lack of healthy foods was observed, which was related to some socio-economic determinants and the multidimensional poverty was the most relevant. The diagnosis of food environments around schools can represent an important target for governments to implement policies focused at improving the availability of healthy foods.

Synthesis of New Chitosan from an Endemic Chilean Crayfish Exoskeleton (Parastacus Pugnax): Physicochemical and Biological Properties.

Chitin is one of the most abundant natural polysaccharides in the world and it is mainly used to produce chitosan by a deacetylation process. In the present study, the extraction of chitin and chitosan from the Parastacus pugnax (P. pugnax) crayfish exoskeleton was studied for the first time. Thus, the P. pugnax crayfish exoskeleton was converted to chitosan following the steps of depigmentation, deproteinization, and deacetylation. The produced chitosan (Chitosan-CGNA) was characterized in terms of the protein content, solubility, degree of deacetylation, viscosity, molecular weight, FTIR, SEM, XRD, antimicrobial, and antioxidant activity. The results showed that the obtained chitosan had a high degree of deacetylation (91.55%) and a medium molecular weight (589.43 kDa). The antibacterial activity of the chitosan was tested against bacterial strains relevant for the food industry and the lowest minimum inhibitory concentration (MIC) values were evidenced with Salmonella tiphymurium (S. typhimurium), Staphylococcus aureus (S. aureus), Enterococcus faecalis (E. faecalis) and Listeria. Monocytogenes (L. monocytogenes). Moreover, the Chitosan-CGNA showed an effect on DPPH radical scavenging activity, and its antioxidant activity was dependent on concentration and deacetylation degree. These results suggest that P. pugnax exoskeleton could be an excellent natural source for the production of chitosan with potential applications in the health system, and to prevent infections associated with pathogens strains.

Craniectomía descompresiva como tratamiento primario de la hipertensión intracraneal por traumatismo encefalocraneano: Experiencia observacional en 24 pacientes

Introducción: el traumatismo encéfalo craneano es una de las principales causas de muerte en nuestro medio, El tratamiento médico y quirúrgico en la etapa inicial de un TEC severo se enfoca en evitar la elevación de la Presión Intracraneana. Objetivo : describir características asociados y sus principales complicaciones en aquellos pacientes sometidos a Craniectomía Descompresiva. Métodos : Estudio retrospectivo observacional descriptivo, realizado entre febrero de 2018 a julio de 2020 de pacientes operados de Craniectomía Descompresiva unilateral, admitidos por traumatismo encefalocraneano. Resultados : 66.7% fueron personas menores de 40 años; 87,5% fueron de sexo masculino; 16,7% de la población ingresaron con una ECG de 13-15, 37,5% de la población con una ECG de 9-12; 42.9% presentaron asimetría pupilar; 33,3% ingresaron por accidente de tránsito; 21,7% fueron Marshall II, 65,2% Marshall III y en 13,0% se halló un Marshall IV. Conclusiones : Los resultados sugieren que las características asociadas a la Craniectomía Descompresiva por TEC contribuyen en el manejo de esta patología.

Introduction: Head trauma is one of the main causes of death in Peru. Medical and surgical therapy during the initial stages of severe head trauma focus in preventing the elevation of intracranial pressure. Objective: To describe the associated characteristics and main complications in patients undergoing decompressive craniectomy. Methods: This is a retrospective observational study performed between February 2018 and July 2020 in patients who had been admitted because of head trauma and who had undergone unilateral decompressive craniectomy. Results: Two-thirds (66.7%) of patients were persons less than 40 years of age; 87.5% were males; 16.7% were admitted with Glasgow Coma Score (GCS) scores between 13 and 15; 37.5% were admitted with GCS between 9 and 12; 42.9% had asymmetric pupils; 33.3% were admitted because of traffic accidents; 21.7% were Marshall II, 65.2% were Marshall III, and 13.0% were Marshall IV. Conclusions: Our results suggest that characteristics associated to decompressive craniectomy because of head trauma contribute for its proper management.

Classical markers like ER and ki-67, but also survivin and pERK, could be involved in the pathological response to gemcitabine, adriamycin and paclitaxel (GAT) in locally advanced breast cancer patients: results from the GEICAM/2002-01 phase II study.

INTRODUCTION: The identification and validation of biomarkers of chemotherapy sensitivity is critical in order to individualise therapy in breast cancer. We evaluated pathological complete response (pCR) to GAT, and its correlation with tumour biomarkers before and after neoadjuvant chemotherapy. MATERIALS AND METHODS: Stage III (and stage II with T≥5 cm) breast cancer patients were included. Treatment consisted of adriamycin (40 mg/m(2)) day 1, and paclitaxel (150 mg/ m(2)) followed by gemcitabine (2000 mg/m(2)) day 2, every 14 days for six cycles. Tissue from pre-treatment biopsy and surgery was evaluated for biologic markers by immunohistochemistry. Two XPD single nucleotide polymorphisms (SNP) were also analysed. RESULTS: Forty-six patients entered the trial. Median age was 49.5 years (range 31-72); 25 patients (54%) were pre-menopausal; 12 (26%) were ER-PgR-negative; pCR was observed in 17% (95% CI: 6.4-28.4) of patients. Significant differences in marker expression (mean±SD) in correlation to pathological response were only found in Ki- 67. After treatment, tumours showed lower Ki-67-, surviving- and pERK-positive cells. No correlation between XPD polymorphisms and pCR was found. The overall response rate was 89% (95% CI: 80.1-98.1). Fifteen patients (33%) underwent breast-conserving surgery. The most frequent grade 3 or 4 toxicities were neutropenia (with one febrile neutropenia) and asthenia. CONCLUSION: These results show an effective regimen with acceptable tolerability. Our data suggest that not only classical markers (ER, Ki-67), but also survivin and pERK could be involved in the response to GAT, which may contribute to therapy individualisation in future study designs.

Random walks and chemical graph theory.

Simple random walks probabilistically grown step by step on a graph are distinguished from walk enumerations and associated equipoise random walks. Substructure characteristics and graph invariants correspondingly defined for the two types of random walks are then also distinct, though there often are analogous relations. It is noted that the connectivity index as well as some resistance-distance-related invariants make natural appearances among the invariants defined from the simple random walks.

Cloning and comparison of ten gene sequences of a Chilean H. pylori strain with other H. pylori strains revealed higher variability for VacA and CagA virulence factors.

We have cloned and sequenced ten Helicobacter pylori genes from a Chilean strain (CH-CTX1) including: a cytotoxin VacA fragment, a CagA fragment (A17), a species-specific protein (TsaA), urease subunits (UreA, UreB), a flagellin subunit (FlaB), heat shock proteins (HspA and HspB), adhesin (HpaA) and a lipoprotein (Lpp20). We compared their deduced amino acid sequences with the corresponding sequences from three unrelated H. pylori strains, including fully sequenced strains 26695(UK) and J99(USA), and found that eight of them (UreA, UreB, FlaB, HspA, HspB, Lpp20, TsaA and HpaA) presented more than 97.3% identity. In contrast, VacA partial sequence showed lower identity values (93.2-94.9%). Moreover, we found major differences in the A17 region respect to the number and arrangement of the internal repeated elements when sequences from different strains were aligned. The A17 regions from strains CH-CTX1 and 26695 are very similar (91.8% identity) but lacked 6 repeated elements when compared to the Australian strains ATCC 43526 and NCTC 11637. The CCUG 17874 A17 region showed the largest deletion involving 9 repeats. A17 size differences between strains CCUG 17874 and CH-CTX1 were verified by PCR and polypeptide size. Such differences may explain variations in virulence among H. pylori strains as well as diversity in serum immunoreactivity.

Cloning and comparison of ten gene sequences of a Chilean H. pylori strain with other H. Pylori strains revealed higher variability for VacA and CagA virulence factors

We have cloned and sequenced ten Helicobacter pylori genes from a Chilean strain (CH-CTX1) including: a cytotoxin VacA fragment, a CagA fragment (A17), a species-specific protein (TsaA), urease subunits (UreA, UreB), a flagellin subunit (FlaB), heat shock proteins (HspA and HspB), adhesin (HpaA) and a lipoprotein (Lpp20). We compared their deduced amino acid sequences with the corresponding sequences from three unrelated H. pylori strains, including fully sequenced strains 26695(UK) and J99(USA), and found that eight of them (UreA, UreB, FlaB, HspA, HspB, Lpp20, TsaA and HpaA) presented more than 97.3% identity. In contrast, VacA partial sequence showed lower identity values (93.2-94.9%). Moreover, we found major differences in the A17 region respect to the number and arrangement of the internal repeated elements when sequences from different strains were aligned. The A17 regions from strains CH-CTX1 and 26695 are very similar (91.8% identity) but lacked 6 repeated elements when compared to the Australian strains ATCC 43526 and NCTC 11637. The CCUG 17874 A17 region showed the largest deletion involving 9 repeats. A17 size differences between strains CCUG 17874 and CH-CTX1 were verified by PCR and polypeptide size. Such differences may explain variations in virulence among H. pylori strains as well as diversity in serum immunoreactivity.