A simple method for detection of mutations in amino acid 452 of the Spike protein of SARS-CoV-2 using restriction enzyme analysis

Variants of Concern or Interest of SARS-CoV-2 (VOC or VOI), the coronavirus responsible for COVID-19, have emerged in several countries. Mutations in the amino acid 452 of the Spike protein are particularly important and associated with some of these variants: L452R, present in Delta VOC, and L452Q, present in Lambda VOI. These mutations have been associated with both increased infectivity and evasion of protective immune response. A search on GISAID to detect the number of sequences harboring the L452R mutation and the frequency of Delta VOC among them, showed that since August 2021, most of these sequences belong to the Delta VOC. Restriction enzyme analysis is proposed as a rapid method to detect L452R. A small amplicon from the Spike gene was digested with MspI. A 100% concordance was observed between digestion and sequencing results. The mutation L452Q can also be detected by restriction analysis, allowing the identification of putative Lambda VOIs. The proposed methodology, which allows screening of a great number of samples, could provide a faster information on the prevalence of Delta VOC cases.

Clinical cardiac alterations and hemostatic toxicities caused by scorpion (Tityus discrepans) venom and its purified fractions on zebrafish (Danio rerio) larvae

Envenomation by the Venezuelan scorpion Tityus discrepans is typified by local and systemic alterations. The current work investigated the in vivo hemostatic processes, cardiac dysfunction and tissue destruction triggered by Tityus discrepans purified toxins 1 (3 kDa) and 2 (5 kDa) fractions. These fractions were obtained by C-18-HPLC chromatography. The hemostatic and cardiovascular toxicities in zebrafish of both fractions was assessed by means of specific phenotypic expressions and larvae behavior at 5, 15, 30, 40 and 60 min post-venom-treatment. The Tityus discrepans venom fractions 1 and 2 produced disseminated intravascular coagulation (presence of thrombus) in the central vein of the larva, heart rate/rhythm alterations, and necrotic events in more than 90% of all the larvae under their action. The outcomes have established the potential hemostatic and cardiovascular toxicities by Tityus discrepans venom, alerting on the possibility of cardiovascular injuries and thromboembolism in humans after scorpion stings envenomation.

Drug-disease interactions of differentially expressed genes in COVID-19 liver samples: an in-silico analysis

While COVID-19 liver injuries have been reported in various studies, concerns are raised about disease-drug reactions in COVID-19 patients. In this study, we examined the hypothesis of gene-disease interactions in an in-silico model of gene expression to seek changes in cytochrome P450 genes. The Gene Expression Omnibus dataset of the liver autopsy in deceased COVID-19 patients (GSE150316) was used in this study. Non-alcoholic fatty liver biopsies were used as the control (GSE167523). Besides, gene expression analysis was performed using the DESeq/EdgeR method. The GO databases were used, and the paths were set at p<0.05. The drug-gene interaction database (DGIdb) was searched for interactions. According to the results, 5,147 genes were downregulated, and 5,122 genes were upregulated in SARS-CoV-2 compared to healthy livers. Compared to the cytochromes, 34 cytochromes were downregulated, while 4 cytochromes were upregulated among the detected differentially expressed genes (DEG). The drug-gene interaction database (DGIdb) provided a list of medications with potential interactions with COVID-19 as well as metacetamol, phenethyl isocyanate, amodiaquine, spironolactone, amiloride, acenocoumarol, clopidogrel, phenprocoumon, trimipramine, phenazepam, etc. Besides, dietary compounds of isoflavones, valerian, and coumarin, as well as caffeine metabolism were shown to have possible interactions with COVID-19 disease. Our study showed that expression levels of cytochrome P450 genes could get altered following COVID-19. In addition, a drug-disease interaction list is recommended to be used for evaluations in clinical considerations in further studies.

Role of the facial artery musculomucosal flap in the reconstruction of palatal defects

The facial artery musculomucosal flap (FAMM flap) is a convenient option for covering complicated palatal defects, as it is a local flap inside the oral cavity with good tissue quality and minimal drawbacks. The present prospective study included 17 patients, 7 males and 10 females. Most of the patients had palatal fistulae, after cleft palate surgical repair; only one had a post-traumatic palatal defect. Superiorly based FAMM flaps were used for eight patients, and inferiorly based FAMM flaps were used for nine patients. A speech specialist assessed all patients, postoperatively. The range of follow-up time was from two to four years. In the majority of cases, reconstruction was successful and uneventful. Patients were satisfied regarding oral function. Complications were minor, which include incomplete coverage, bulkiness, temporary hardness and dimpling. The FAMM flap is a very useful, versatile, and technically easy flap for covering difficult palatal defects.

Thymosin β4 regulates endothelial cell function via activating the AKT pathway

The vascular eendothelial cells are highly heterogeneous and associated with numerous diseases. Thymosin β4 (Tβ4) plays pleiotropic roles in endothelial cell differentiation, migration and angiogenesis. However, the underlying mechanisms played by Tβ4 in the regulation of endothelial cells have not yet been well investigated. In the present study, Tβ4 -GFP adenovirus, transfected into human umbilical vein endothelial cells (HUVECs), and cell morphology were analyzed by fluorescence microscopy. ELISA was used to determine the concentration of Tβ4 expression. Furthermore, the effects of Tβ4 overexpression on HUVECs proliferation, apoptosis and migration were investigated. Real-time quantitative PCR and western blot were conducted to examine mRNA and protein expression in HUVECs with Tβ4 overexpression. Moreover, the underlying molecular mechanism of Tβ4 in HUVECs function was tested through treatment with LY294002, a PI3K/AKT inhibitor. Overexpression of Tβ4 increased the cell ability of HUVECs, and up-regulated the expression of the proliferation markers PCNA and Cyclin D1. In addition, overexpression of Tβ4 reduced HUVECs apoptosis, both under normoxic and hypoxic conditions. Moreover, overexpression of Tβ4 increased the ability of HUVECs to migrate through the membrane and up-regulated levels of MMP-2 and MMP-9. The use of LY294002 decreased the p-AKT (Ser473) level, which was induced by Tβ4 overexpression. Importantly, LY294002 reduced Tβ4-induced HUVECs proliferation and migration. In conclusion, our results suggest that Tβ4 is a major regulator of HUVECs function by activating the AKT signaling pathway.

Características tomográficas de las lesiones pulmonares en pacientes hospitalizados con COVID-19 y su valor pronóstico

La gravedad de las imágenes en la tomografía (TC) de tórax en pacientes con COVID-19 puede tener valor pronóstico. Este estudio evalúa el tipo, gravedad y frecuencia de las lesiones pulmonares de pacientes hospitalizados con COVID-19 y las diferencias en las características clínicas y desenlaces intrahospitalarios según la gravedad tomográfica. Se trata de un estudio observacional (cohorte retrospectiva) de pacientes hospitalizados con COVID-19. Se usó el formulario de ISARIC-OMS para recopilar datos. Se determinó el tipo de lesiones pulmonares, lóbulos afectados y puntuación de gravedad total en la TC de ingreso. Se calcularon el primer, segundo y tercer cuartiles de la puntuación total, para dividir la muestra en cuatro partes iguales (Q1, Q2, Q3 y Q4). Se incluyeron 556 pacientes, 336 hombres (60,4%) y 220 mujeres (39,6%), con edad promedio 61,9±15,8 años y 532 tenían TC al ingreso. Los pacientes en los cuartiles más graves tenían más días de evolución de síntomas (Q1 6,4±3,5, Q2 7,9±4,1, Q3 8,2±4,1, Q4 8,1±4,4), desaturación (Q1 95,3±3,7%, Q2 94,4±3,1%, Q3 91,7±4,8%, Q4 86,5±9,1%), alteración de marcadores inflamatorios, días de hospitalización (Q1 6,4±2,9, Q2 7,4±4,1, Q3 9,6±5,8, Q4 13,1±10,4), admisión a UCI (Q1-2,5%, Q2-5,8%, Q3-12,5%, Q4- 49,1%), mortalidad (Q1-3,8%, Q2-4,5%, Q3-9,4%, Q4-33,3%), lesiones combinadas (vidrio deslustrado-consolidado) en la TC, opacidades lineales, patrón-empedrado, halo-invertido y bronquiectasia. La puntuación de la TC se correlacionó significativamente con el recuento de leucocitos, neutrófilos, linfocitos y otros marcadores inflamatorios. La evaluación semicuantitativa del compromiso pulmonar en la TC de tórax, puede ayudar a establecer la gravedad y predecir desenlaces clínicos en pacientes con COVID-19.

El médico: su satisfacción como paciente o como tratante de otro médico. Comparación con la población general en Venezuela: estudio piloto

La forma como el médico aborda su salud, la de su familia y la de los colegas a los que atiende es un tema de interés práctico y humanístico. Sin embargo, las publicaciones sobre este tema son escasas y la discusión se basa a menudo en información anecdótica. En el presente estudio se determinó en Mérida, Venezuela, el grado de satisfacción de los médicos con la atención que han recibido como pacientes, y se comparó en forma concurrente con la de sujetos de la población general (PG). Se evaluó igualmente el nivel de satisfacción de los médicos en su condición de profesionales tratantes de otro colega. La hipótesis de trabajo fue que un porcentaje significativo de médicos tiene una opinión negativa, influida por su edad y sexo. La variable objeto de estudio se analizó en tres niveles: 1) opinión positiva o satisfacción; 2) opinión neutra, y 3) opinión negativa o insatisfacción. El marco temporal fue el nivel de satisfacción/insatisfacción ‘en general’, y la ‘última vez’ que se brindó o se recibió asistencia profesional. Se seleccionaron en forma probabilística 52 médicos especialistas, 84 médicos residentes y 494 sujetos de la PG. Se utilizó una encuesta autoadministrada cuyo análisis psicométrico demostró un coeficiente de validez de contenido de 0,82, el cual califica como ‘bueno’. Los especialistas masculinos reportaron las frecuencias más elevadas de insatisfacción con el trato recibido de sus pacientes médicos (28,6%, p = 0,05-0,1) y en su desempeño profesional con los colegas (7,1%, p >0,05). De igual forma, los especialistas masculinos presentaron las frecuencias más elevadas de insatisfacción como pacientes (38,4-42,9%, p <0,05). Las residentes reportaron los niveles más bajos de insatisfacción como pacientes o tratantes entre los médicos, aunque los valores no alcanzaron significación estadística. La PG masculina reportó valores significativamente más bajos de insatisfacción que todos los médicos (6,6%, p <0,05). En conclusión, una frecuencia significativa de médicos, particularmente los hombres especialistas, está insatisfecha tanto como tratante de otros médicos, como en su rol de paciente. Deben diseñarse programas de educación profesional ad hoc para abordar esta importante dinámica asistencial.

Cáncer y Microbiota

El cuerpo humano está expuesto continuamente a microorganismos tanto fijos como transitorios, así como sus metabolitos tóxicos, lo cual puede conducir a la aparición y progresión del cáncer en sitios distantes al hábitat particular de cada microbio. Diversos estudios científicos han hecho posible entender la relación estrecha que existe entre microbioma y cáncer, ya que los componentes del primero, al tener la capacidad de migrar a diferentes zonas del cuerpo, pueden contribuir al desarrollo de diversas enfermedades crónicas. Los estudios de metagenómica sugieren que la disbiosis, en la microbiota comensal, está asociada con trastornos inflamatorios y varios tipos de cáncer, los cuales pueden ocurrir por sus efectos sobre el metabolismo, la proliferación celular y la inmunidad. La microbiota puede producir el cáncer cuando existen condiciones predisponentes, como en la etapa inicial de la progresión tumoral (iniciación), inestabilidad genética, susceptibilidad a la respuesta inmune del huésped, a la progresión y la respuesta a la terapia. La relación más estrecha, entre el microbioma y el cáncer, es a través de la desregulación del sistema inmune. En este trabajo revisamos las actuales evidencias sobre la asociación entre la microbiota y algunos tipos de cáncer como el cáncer gástrico, colorrectal, próstata, ovario, oral, pulmón y mama.

Primary Dysmenorrhea: pathophysiology

The present study was conducted to investigate and analyze the recent and relevant studies about primary dysmenorrhea and its pathophysiology. Literature searches were performed electronically in PubMed, Medline, ISI, DOAJ, Springer, Embase. Web of Knowledge, DOAJ, Google Scholar and the Cochrane Library for original articles written in English and in Scielo, Lantidex, Imbiomed-L, Redalyc and Google Scholar for original articles written in Spanish. The searches included the key words (Mesh): menstruation, menstrual period, menstrual cycle, dysmenorrhea, primary dysmenorrhea, inflammatory substance and inflammatory markers. Publications from January 1980 to February 2021 were reviewed. Dysmenorrhea is the most common gynecologic condition experienced by menstruating women. It is characterized by crampy lower abdominal pain that can range widely in severity, and associated to others symptoms. Its overall impact often has significant medical and psychosocial implications. The hallmark of primary dysmenorrhea is painful menses in the absence of any associated macroscopic pathologic process, and it occurs in up to 50% of menstruating females and causes significant disruption in quality of life and absenteeism. An excessive or imbalanced amount of prostanoids and possibly eicosanoids released from the endometrium during menstruation have been mentioned as the main cause of primary dysmenorrhea. The uterus is induced to contract frequently and dysrhythmically, with increased basal tone and increased active pressure. Uterine hypercontractility, reduced uterine blood flow and increased peripheral nerve hypersensitivity induce pain. Diagnosis rests on a good history with negative pelvic evaluation findings. This narrative review investigated and analyzed the pathophysiology of primary dysmenorrhea and the implications of other chemical substances.