Novel Approach to Screening Mutations Causing Retinoblastoma, a Childhood Cancer of Retina
Retinoblastoma (RB) is a childhood retinal cancer caused by mutations in the RB1 gene. Molecular diagnosis is crucial for early detection and treatment. Current DNA diagnostic screening requires substantial amounts of tumour and blood samples. However current screening methods face the challenges of limited DNA templates from minute retinal tumours and too much blood samples drawn from young patients. In addition, the starting DNA template amount and quality are important to ensure confident detection of disease-causing mutations. As the majority of RB1 mutations are unique and distributed throughout the RB1 gene with no real hot spots, the entire gene needs to be thoroughly analysed. This investigation proposes to enrich DNA samples using a whole genome amplification (WGA) step prior to RB1 mutation screening by RB1 gene-specific PCR amplification as well as high resolution melt (HRM) analysis and sequencing. It also identifies RB1 mutations in two RB patients and explores whether WGA and saliva products can be a source of DNA templates for RB1 analysis. In addition, this study was conducted based on the hypotheses that RB1 mutations were the underlying cause of the disease in the two patients, and that the products from WGA could be used specifically for RB1 gene analysis to overcome the constraint of insufficient DNA samples. Two anonymised genomic DNA samples from two unrelated RB patients and five normal healthy DNA samples were used in this project. WGA kits were compared according to three criteria, namely amplification yield, product fragment size and whether DNA is amplifiable. Prior to and after amplification, the optical density of two normal samples was measured to determine the increase in DNA yield. The amplicons were subjected to gel electrophoresis to determine the product fragment size. Exons 6, 14 and 25 of the original and amplified samples undergone PCR, and were examined again using gel electrophoresis to ascertain that the amplicons were amplifiable. Mutation analysis using HRM was carried out with pre-existing primers for all 27 exons and the promoter of RB1. Samples from patients were analysed against 83 saliva DNAs extracted using Oragene•DNA (OG-500) Kit. REPLI-g was observed to produce higher yield and products of reliable fragment size. Single distinct bands were also seen for exons amplified using REPLI-g, indicating that REPLI-g is more accurate and suitable in the amplification of DNA. Abnormal melt profiles were obtained for exon 6 in RB477 and exon 14 in RB572 for HRM. These exons were sequenced to determine the exact mutation. Exon 6 was found to have a splice-site mutation g.607+1G>T, while a point mutation, g.1363C>T (p.Arg455X) was identified in exon 14. Both the uses of saliva as a non-invasive DNA source and the WGA approach for enriching DNA sample for application in RB1 gene analysis have never been reported for RB. Although HRM analysis has been used for other diseases, this is its first instance applied in work on RB1 gene. In short, this report offers novel and promising approaches which would contribute significantly to the molecular analysis of mutations in RB.
探討抗憂鬱症藥物phenelzine對於發生在小鼠巨噬細胞中的細胞凋亡所產生的保護作用及機制
之前有研究指出，使用一些單胺氧化酶(monoamine oxidase, MAO)的抑制劑如pargyline和clorgyline，皆可以保護serum starvation所導致的細胞凋亡，表示MAO可能在細胞凋亡的路徑中扮演重要的角色。 本研究著重於一個臨床上被拿來當抗憂鬱症藥物的MAO抑制劑苯乙肼(phenelzine, PZE)對於沿著腫瘤壞死因子-α (tumor necrosis factor-α, TNF-α)途徑而產生細胞凋亡的小鼠骨髓巨噬細胞(bone marrow-derived macrophages, BMDM)所產生的保護作用。 本研究的結果顯示PZE的確可以保護循TNF-α途徑死亡的細胞，同時使活性氧化物質(reactive oxygen species, ROS)的量下降。我們推論造成此現象的原因是PZE藉由抑制MAO，使得ROS的量下降，進而保護細胞。
Geographic Belts for Hurricane Landfall Location Prediction
When predicting a hurricane’s landfall location, small improvements in accuracy result in large savings of lives, property, and money. The project’s purpose was to apply a breakthrough method that can predict the geographic location of a hurricane’s landfall with high accuracy. Researchers have known for a long time that there are strong correlations between a hurricane’s landfall location and the geographic regions its track passes through. However, no methods have been developed to mathematically and explicitly describe these correlations. Consequently, the correlations can only serve to meteorologists as vague guidelines for their guestimates and are not usable in making practical forecasts. By studying the correlations and performing numerical optimization on historical hurricane data, this research discovered a set of geographic belt regions in the Gulf of Mexico that can be used as landfall location predictors. When a hurricane passes through any one of these belt lines, a prediction can be made by extending the hurricane’s moving direction vector towards land – the intersection point of this extension line with the coastline is the predicted landfall location. This prediction method is simple and straightforward. It only uses basic measurements from meteorological satellites: the hurricane’s real-time locations and moving directions. In conclusion, when compared to existing methods, the predictive belt method (PBM) created in this research provides a landfall location forecast with higher accuracy. Verification with historical hurricane data demonstrated that the PBM’s average error is less than 50% of the National Hurricane Center models’ error.
Biodegrable Roof
It became necessary to implement a project for the use of vegetable waste generated in the process of handling plantain cultivation, harvest and postharvest, since in Mexico at harvest large quantities of vegetable waste is produced, since only the fruit is used wasting the Pseudostem with leaves and spine. Based on this information, you can take advantage of banana fiber as raw materials in the manufacture of biodegradable sheets and support options that are feasible and possible to make alternative. This is an inexpensive process, also friendly with the environment, so that thousands of banana plants that bear fruit after they become sterile and are discarded without realizing their Pseudostem.