全國中小學科展

醫學與健康科學

Preparation of a Specific Detector for Aspergillus Niger in Swimming Pools

Swimming pools are one of the transmission routes of superficial and cutaneous fungal infections. Maintenance of environmental hygiene in different parts of swimming pools is of great importance, especially the hygiene of water (1). The conventional fungal detection methods include direct smear preparation, culture, and pathological examinations. However, these methods are not fast enough or do not have sufficient sensitivity (2). Therefore, the present research introduces a novel method for detecting Aspergillus niger in pool water through creating optimal conditions for this fungus, which leads to the citric acid production by the fungus and pH changes of the related culture medium. Four experiments in 10 steps were performed to find the optimal conditions for fungal growth. According to our results, adding each of the variables sucrose, soy, and ferrous sulfate can lead to favorable results. Moreover, the shaker speed increase and fungal aeration are important. Also, we showed that soybean led to the best results compared to other variables. Considering the obtained results, including the shortened detection duration and cost-effectiveness, this method can be presented to the swimming pool owners and pathobiology laboratories as the method of choice for Aspergillus niger detection.

HOST TARGET PROTEINS OF SPIKE PROTEIN OF SARS-COV-2

Coronavirus Disease 2019 (COVID-19) is a newly emerged infectious disease caused by the new severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV-2). In less than one year, the virus has spread around the entire world, killing millions of people and disrupting travel and business worldwide. During infection, the virus uses its Spike protein to dock onto the Ace2 protein on the surface of its human host cell. Spike is 1273 amino acids long and only a short fragment of Spike (319-541) is sufficient to bind Ace2. We hypothesized that the remaining protein sequences of Spike might have functions for viral replication beyond the binding of Ace2. We have performed Split-Ubiquitin protein-protein interaction screens to isolate human proteins by their ability to bind to Spike, and we have identified Annexin2A2 and Cytochrome b as novel human protein interaction partners of Spike. Annexin2A2 is involved in both endocytosis and exocytosis, and the protein interaction with Spike might help the virus to enter and exit its host cell. The presence of the mitochondrial Cytochrome b protein inside the cytosol promotes apoptosis, and the protein interaction with Spike could speed up sapoptosis of the infected human cell. The Nub cDNA libraries that we have generated also allowed us to screen for synthetic peptides that interact with Spike. We have isolated two synthetic peptides, FL1a and FL7a, derived from the non-coding parts of human mRNAs by their ability to interact with Spike. We found that both FL1a and FL7a interact with the C-terminal half of the Spike protein. We also found that FL7a is able to block the Spike-Spike self-interaction at the C-terminal half of the Spike protein and we think that this could block the reassembly of the Spike protein in the host cell during viral reassembly. We hope that those synthetic peptides could be used as drugs due to their ability to block protein-protein interactions of Spike with human host proteins that are essential for viral replication.

探討胞外基質軟硬度對神經突生長發育的影響

文獻指出若神經導管能針對不同組織調整適切軟硬度,將更有效協助神經再生,因此,了解胞外基質軟硬度對神經細胞的影響和其感知路徑非常重要。本研究以神經母細胞瘤Neuro-2a進行研究,分析不同軟硬度基質上N2a細胞面積、神經突長度。結果顯示分化後N2a細胞在100 KPa基質上面積大且神經突較長,說明N2a細胞能偵測基質軟硬度並進行生長調控。同時,advillin、paxillin、myosin IIa和pFAK等細胞骨架蛋白於細胞本體表現量在不同軟硬度基質上有所差異,但未與神經突長度相關。生長錐上細胞骨架蛋白表現量於不同軟硬度基質上具有差異,且與神經突長度趨勢吻合,說明神經細胞透過調控advillin和細胞骨架蛋白在生長錐上的表現量影響神經突生長長度。未分化N2a細胞轉染pAdvillin-IRES-hrGFP和pS1S3-HP-FLAG後長出神經突,且根據基質軟硬度生長情形不同,但轉染pS1S3-HP-FLAG長出的神經突長度較短,說明advillin的nucleation功能在神經突生長扮演重要角色。

探討組蛋白脫乙醯酶HDAC7對於癌細胞DNA損傷修復機制之影響

DNA損傷導致的基因體不穩定是癌症的共同特徵,而細胞依賴DNA損傷反應 (DDR) 來感知和修復受損的DNA,以維持基因體完整。DDR由DNA損傷傳感信號和修復網絡組成, DDR的活化可阻滯細胞週期並啟動DNA修復,是應對DNA損傷的關鍵步驟。其過程受許多因素調控,包括多種轉譯後修飾如乙醯化、脫乙醯化、小泛素化等。HDAC7是組蛋白脫乙醯酶,該家族成員有多個已被證實參與DDR且在多種癌細胞中常過量表現。最近研究發現HDAC7具小泛素蛋白E3連接酶活性,但相關研究甚少,因此欲探討HDAC7在DDR所扮演的角色。 本研究使用西方墨點法、免疫螢光染色、流式細胞儀分析、細胞存活率測試和細胞群落形成能力實驗,發現以RNAi技術將細胞的HDAC7基因沉默後會降低DNA損傷引起的ATR-Chk1及ATM-Chk2訊號強度,使不能有效率活化檢查點,並對DNA損傷藥物較敏感。由以上結果顯示,HDAC7有潛力做為抗癌藥物研發的新目標。

Preparation of a Specific Detector for Aspergillus Niger in Swimming Pools

Swimming pools are one of the transmission routes of superficial and cutaneous fungal infections. Maintenance of environmental hygiene in different parts of swimming pools is of great importance, especially the hygiene of water (1). The conventional fungal detection methods include direct smear preparation, culture, and pathological examinations. However, these methods are not fast enough or do not have sufficient sensitivity (2). Therefore, the present research introduces a novel method for detecting Aspergillus niger in pool water through creating optimal conditions for this fungus, which leads to the citric acid production by the fungus and pH changes of the related culture medium. Four experiments in 10 steps were performed to find the optimal conditions for fungal growth. According to our results, adding each of the variables sucrose, soy, and ferrous sulfate can lead to favorable results. Moreover, the shaker speed increase and fungal aeration are important. Also, we showed that soybean led to the best results compared to other variables. Considering the obtained results, including the shortened detection duration and cost-effectiveness, this method can be presented to the swimming pool owners and pathobiology laboratories as the method of choice for Aspergillus niger detection.

香杉芝誘導黑色素癌細胞凋亡與自噬性死亡

香杉芝(Antrodia salmonea)是台灣特有的食藥用菇,具抗血癌、抗發炎及抗動脈硬化的功能。我們研究發現,香杉芝發酵液會誘導人類黑色素癌(A2058/A375)細胞毒性;比較香杉芝抗癌活性發現毒殺A2058強於A375細胞。我們亦發現,香杉芝作用黑色素癌(A2058)細胞,會誘導晚期凋亡(Annexin V-PI 雙染法)、Caspase-3增加及PARP裂解;產生自噬酸性囊泡(AVO)、促自噬蛋白LC3-II增加。加入細胞凋亡抑制劑 Z-VAD-FMK及自噬抑制劑3-MA/CQ可保護香杉芝誘導癌細胞死亡。此外,香杉芝會誘導黑色素癌細胞Bax/Bcl-2及Beclin-1/Bcl-2比例增加。推論,香杉芝可同時誘發黑色素癌細胞凋亡(Apoptosis)及自噬性死亡(Autophagy)。香杉芝會誘導黑色素癌細胞活性氧化物(ROS)生成;抗氧化劑N-acetylcysteine可減緩香杉芝對黑色素癌細胞毒殺。推測,香杉芝是透過ROS來殺死黑色素癌細胞。我們亦發現,香杉芝可與抗癌藥物Paclitaxe對黑色素癌細胞產生協同作用(CI<1)。總結,香杉芝發酵液具抗黑色素癌功效,可開發成抗癌的藥品/保健食品。

探討病毒配體與樹突細胞間的交互作用

由於新冠肺炎的影響,引發了世界的一陣恐慌,也促使我對於免疫系統及病毒之間的交互作用有了更濃厚的興趣。而在疾病的肆虐之下,疫苗儼然成為對抗病原體的重要武器。試想我們若能找到某些化合物,在未找到特定疾病的疫苗之前,能藉由化合物刺激增強人體免疫能力,進而達到對抗病毒的功效,或許會是未來萬用疫苗的首選。 目前已知一種配體R848在RNA病毒界具有一定的代表性,在動物實驗中對冠狀病毒的感染也有一定的功效,因此我希望進一步探究此配體在免疫系統中的作用。本研究以細胞株及小鼠骨髓細胞為材料,以R848、CpG等2種不同的配體刺激,發現R848濃度會影響細胞的分化種類及活性,而經過CpG再刺激的細胞將會被活化。且若於發育過程受到持續高濃度R848刺激,將會使細胞活性下降,進以避免自體免疫反應的發生。透過此研究,可初步了解R848影響免疫系統的途徑。

Anti-bacterial Crab bio-bandages with Bio-dressings 2.0

Commercially available bandages such as hydrocolloid are neither biodegradable nor anti-bacterial. Chitin is known to be the second most naturally available polysaccharide which could be transformed to chitosan which is known to be anti-bacterial (Hasan, 2018) (Chao, 2019) and haemostatic (Okamoto, 2003) (Hu, 2018). Chitosan can be further converted to hydrogel which is bio-degradable and has good water absorbance. Anti-bacterial crab bio-bandages and crab bio-dressings should be bio-degradable as it took 42 days and a month for complete bio-degradation respectively, so they should be better than commercial bandages such as Nexcare Hydrocolloid as the disposal of anti-bacterial crab bio-bandages with bio-dressings would no longer pose burden to landfilling or threat to our environment. Anti-bacterial crab bio-bandages with bio-dressings are anti-bacterial with degree of deacetylation of DD% (measured using FTIR Spectrum II) 82.6% (due to the presence of chitosan) even without the application of other anti-bacterial agents and hence can provide complete protection of wounds from skin and soft tissues infections and haemostatic (due to the presence of chitosan). After testing and certification based on IS997:2004 and BS EN 13726-1, they should meet many requirements specified. Anti-bacterial crab bio-bandages should be eligible for marketing. Some results were as follows: 1.4 Anti-bacterial effect of crab hydrogels and roasted crab hydrogels Pure chitosan, crab chitosan, crab hydrogels and roasted crab hydrogels showed significant anti-bacterial effect. NO oral bacterial colonies were present in drinking water with crab hydrogels. Thus crab hydrogels could serve as effective anti-bacterial wound dressings. 1.6 Basing on IS997:2004 standard, the load per unit of area of anti-bacterial bio-bandages was 342g/m2 which met the minimum requirement of 36g/m2, the anti-bacterial bio-bandages had stronger tension strength (>20N both in dry and wet conditions) than commercial hydrocolloid. (2.7N dry 2.8N wet) which was comparable with that required (50-67N) and pH of about 7 which met the pH range of 4.5-8. 1.7 The FSA Free-Swell Absorbency of synthetic blood of crab hydrogel bio-dressings was 1.86g per 5cm x 5cm dressing which was much higher than that of commercial hydrocolloid (0.299g per 5cm x 5cm dressing) based on BS EN 13726-1.

尿液中不同物質對磷酸鈣、草酸鈣與尿酸結晶速率的影響

本研究主要研究人類尿液中,腎結石中的奈米細菌(nanobacteria)是礦物結晶或細菌成長作用,使用自製分光光度計,以OD值的差異劃分,結果顯示奈米細菌呈現礦物結晶特徵,成分分析亦證為磷酸鈣。之後研發腎結石抑制劑時,使用自製人工尿液,以磷酸鈣Ca3(PO4)2、草酸鈣CaC₂O₄和尿酸(C5H4N4O3)為主體,分別測試維他命C、(•OH)、模擬管壁發炎、模擬尿液pH值變化,並觀察其結晶型態變化,結果發現模擬管壁發炎OD值最高1.4,尿液pH值5時OD值 1.3次之。推斷腎結石主因與管壁發炎最密切,其次是pH值變化,偏酸與過鹼皆易產生結晶。最後以自製的結石抑制劑比較傳統C6H5K3O7(檸檬酸鉀) 抑制劑,本研究抑制劑OD值呈現較佳抑制效果。

癌症治療新利器-奈米氧化鐵藥物磁性複合微粒之應用

溫熱化學治療(Hyperthermic Intraperitoneal Chemotherapy, 簡稱HIPEC),為將化療藥物加熱後灌注到腹腔內殺死癌細胞,但溫熱化學治療只能在開刀時使用,治療次數有限。為達到多次的熱化療效果,本研究開發奈米氧化鐵藥物磁性複合微粒(Nano iron oxide magnetic drug complex particles, NIOMP),可利用開刀時包覆複合微粒於腹腔,術後用磁場加熱,加上微粒化療藥物釋放,達到多次溫熱化學治療。NIOMP以鐵氧化物奈米粒子為核心,海藻酸鈉為外殼體,利用電紡法將前其與氯化鈣交聯產生凝聚性微粒。數據顯示最佳製作條件為16 kv高電壓、距離4 cm、噴速5μm/s,可得直徑大小約為200~450 μm穩定性高微粒。藥物釋放實驗顯示,NIOMP於2~7小時藥物釋放速率較穩定。利用可變磁場之電磁效應加熱NIOMP中氧化鐵磁顆粒,可於30分鐘內快速升溫至43℃。細胞相容性測試結果得知,NIOMP對細胞無毒性。本研究改善HIPEC的治療限制,可多次針對腫瘤患部局部熱化學治療,未來將可改善病人存活率。