The effect of Cissus quadrangularis Salisb. extract on maturation of rat mesenchymal stem cells.

Degenerative diseases, such as osteoporosis, could be treated by stem cells. The aim of this study was to identify the gene expression of bone marrow mesenchymal stem cells (BM-MSC) derived from Sprague Dawley rats and to assess the effect of Cissus quadrangularis Salisb. extract on their maturation into bone cells. The BM-MSC were divided into three groups: (a) BM-MSCs + osteoblast cell growth basal medium as the positive control; (b) BM-MSCs + Dulbecco's modified eagle's medium (DMEM) + 0.3 mg/mL methanol extract of C. quadrangularis as methanol group; and (c) BM-MSC + DMEM + 0.3 mg/mL ethyl acetate extract of C. quadrangularis as ethyl acetate group. A relative quantification approach using was used to analyze the expression of the alp (alkaline phosphatase) gene, with the beta-actin gene was used to normalize the expression of the alp gene. The intra-assay variation was calculated to validate the RT-qPCR data. Our study found that the intra-assay variation value was acceptable, with most of the coefficients of variability (CV) value <5. Ethyl acetate solvent outperformed methanol solvent in extracting the active compound C. quadrangularis. In the ethyl acetate extract group, the expression of the alp gene increased three times compared to the positive control. In methanol extract group, the expression of alp gene was lower six times compared to positive control. This study suggests that C. quadrangularis extracts using ethyl acetate could induce the maturation of BM-MSCs. However, further studies are warrant to confirm this effect using different indicators.

Discordant results of SARS-CoV-2 PCR-based tests in the early phase of pandemic in Indonesia: Infection control consequences.

Introduction: Growing evidence suggest that cycle threshold (CT)-value of reverse transcription polymerase chain reaction (RT-PCR) is correlated with transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and some kits set different CT-value cut-off. This report presents the discordant results of two widely used RT-PCR kits in Indonesia due to different CT-value cut-offs and highlights its potential consequence in SARS-CoV-2 containment. Methods: Nasopharyngeal swab samples with SARS-CoV-2 negative with a RT-PCR kit (manufacture pre-set CT-value cut-off was 35 amplification cycles) were retested with another RT-PCR kit with a higher pre-set CT-value of 40 amplification cycles. All procedures were performed according to the manufacturer protocols. Results: In total, 30 samples with SARS-CoV-2 negative for the first kit were retested. We found that 25 out of 33 samples (75.5%) were positive using the second RT-PCR kit that had a higher manufacture pre-set CT-value cut-off. In addition, among 500 RT-PCR tests using the first RT-PCR kit, 103 of them (20.6%) were categorized as inconclusive results based on the second manufacturer' guideline. Discussion and conclusion: Our data suggest the possibility of discordant results of SARS-CoV-2 detection due to different pre-set cut-offs by the companies. As consequence, this could leave a fraction of individuals who were misclassified that could act as source of virus transmission within community.

Introducción: La evidencia creciente sugiere que el valor del ciclo umbral (CT) de la RT-PCR (reacción en cadena de la polimerasa por transcripción inversa) guarda relación con la transmisión del síndrome respiratorio agudo severo por coronavirus 2 (SARS-CoV-2), y algunos kits establecen diferentes puntos de corte para dicho valor. El presente informe presenta la discordancia de los resultados de dos kits RT-PCR de amplio uso en Indonesia debido a los diferentes puntos de corte del valor CT, y subraya su consecuencia potencial para la contención del SARS-CoV-2. Métodos: Se reanalizaron las muestras de los hisopos nasofaríngeos negativos para SARS-CoV-2 con un kit RT-PCR (el punto de corte del valor CT preestablecido de fábrica fue de 35 ciclos de ampliación) con otro kit para RT-PCR con un valor CT establecido superior, de 40 ciclos de ampliación. Todos los procedimientos fueron realizados con arreglo a los protocolos de fabricación. Resultados: En total se reanalizaron 30 muestras con SARS-CoV-2 negativas para el primer kit. Encontramos que 25 de entre 33 muestras (75,5%) eran positivas utilizando el segundo kit para RT-PCR, que tenía un punto de corte del valor CT preestablecido superior. Además, entre las 500 pruebas RT-PCR que utilizaron el primer kit para RT-PCR, 103 de ellas (el 20,6%) fueron categorizadas como resultados no concluyentes sobre la base de la guía del segundo fabricante. Discusión y conclusión: Nuestros datos sugieren la posibilidad de discordancia en los resultados de detección del SARS-CoV-2 debido a los diferentes puntos de corte preestablecidos por los fabricantes. Por tanto, esto podría suponer que la mala clasificación de una parte de los individuos fuera la causa de la transmisión del virus dentro de la comunidad.