全國中小學科展

醫學與健康科學

誘發肺癌細胞產生細胞凋亡之天然物篩選及其機轉探討

癌症多年來為台灣地區十大死亡原因之首,因此,開發治療癌症的藥物有迫切的需要。本實驗先以SRB assay篩選許多天然化合物,並找到天然物「禾本科竹節草(Chrysopogon aciculatus)成分CA-C」對肺癌細胞A549有抑制作用;利用流式細胞儀分析細胞週期,顯示DNA片段化,此為細胞凋亡一大特色;並以Western blot評估其對肺癌細胞造成的細胞凋亡之機轉。

動物血型及血清的研究

人類血清中存在天然的抗體,能認識A型紅血球的A抗原及B型紅血球的B抗原,因此寫型不合的血液混合會導致血液凝結。在我們的實驗中,我們發現一種異體的血清與血球相混合也會產生凝集反應,顯示動物的血清中也存在認識異種異體紅血球抗原的天然抗體。然而在實驗是常用的基因相異的七種不同品系小鼠及一種大鼠血清中,卻看不到存有天然抗體可認識彼此血球的抗體而產生凝集反應,顯示老鼠似乎異於人類,血清中沒有天然抗體來引發彼此的血球凝集。而且抗馬血清可與經電泳分離後的馬血清在洋菜膠上形成三個沉澱線,但不會與老鼠血清及牛血清有任何反應。雖然抗馬血清與人及兔血清有交叉反應,但仍顯示出其結合的特異性。除此之外,我們發現來自不同品系的小鼠及大鼠的白血球彼此會互相反應並聚集在一起,顯示不同品系的小鼠及大鼠白血球可認識同種異體及異種異體的白血球抗原。因此不只是血清中的抗體,白血球本身也可認識同種異體及異種異體的抗原。所以除了人類血清中天然抗體及經由免疫注射產生的抗馬血清之外,為經過免疫注射的人或老鼠身上的白血球也具有認識同種異體及異種異體抗原的能力,因此我們認為不僅是抗體,連白血球都可當作鑑別物種的診斷工具。

臉上真的有蟲嗎?~揭開蠕型?的真面目

I’ve heard a report on the internet that there are mites on the face, even a clean face, and I took an interest in doing a research. First, I found that on the face is Demodex, which lives and depends on human beings; besides, nearly seventy percent of people have these mites on their faces. To know more about the habit of Demodex, I sampled forty people of both sexes and different ages. The analysis, not correlating with sex and times of face washing, showed that more mites are found on the forehead than on other parts of the face, and there is more probability to find Demodex on the face of those who are older, those who have oily skin, and those who suffer from acne. I also observed that these mites are photonegative, often gather together in the hair follicles, and feed on sebum. Moved from the human body, Demodex is livelier in sesame oil than in other kinds of oils, but its life ends in about eight to ten hours and dissolutes at last. In addition, I tried to devitalize Demodex by various kinds of medicine, cleansers and cosmetics, but only those containing sulfer, eau de parfum, and the essence of rosemary or lavender are efficacious. 網路傳聞乾淨的臉上也有蟲,引起我探索的興趣,查探後發現是和人類片利共生的毛囊 蠕形?和皮脂蠕形?,初步調查顯示近70%的人臉上都有蟲。為了更了解蟲的習性,以年齡 與性別區分共在40 人臉上採集樣本,統整結果得知,額頭比其他臉上部位多、年齡越大、膚 質油的發現機率較大,但不受面皰多寡、性別、洗臉次數等影響;觀察後發現蠕形?以人類 的皮脂為食,經常群聚在人體毛囊中,離開人體後在芝麻香油中活動力較佳,但約8~10 小時 後就死亡分解導致無法繼續觀察其生活史,對光有明顯的負趨光性,最後試著用各種藥品減 低蟲的生命力,以薰衣草、迷迭香精油、毒藥香水和蜜花沉澱硫等較有效。

研究傳統降火氣食品是否具有抗發炎效果

在炎炎夏日總希望來點可以「降火氣」的食品,依據古籍記載某些中藥材具有降火氣的效應,而中醫所謂的降火氣與西醫的抗發炎反應密切相關。本實驗利用巨噬細胞株受到LPS (Lipopolysaccharide,革蘭氏陰性菌細胞壁表面所含有的脂多醣體)刺激後,會分泌發炎介質的現象,再分別加入各項傳統認為可降火氣(以菊花、薏仁、仙草作為樣品)或上火氣(選用龍眼作為樣品)的中藥食材,來評估中藥材對巨噬細胞分泌發炎介質能力的影響。經由實驗,我們發現市售的『降火氣』中藥食材,在適當的濃度下,確實具有降低IL-6、TNF-α 分泌量的能力,但濃度過高時卻會造成細胞凋亡。另外,傳統以水熬煮的方式比冷凍乾燥取得的樣品有更好的降低IL-6、TNF-α 分泌量的能力。 我們期望以此一系列的實驗,來建立篩選『降火氣』食材的抗發炎效用的研究模式,並在後續實驗中可用以篩選出更多具抗發炎效應的中藥材。In summer, people always consider eating some special things to refresh themselves. According to ancient books, there are some Chinese herbal medicines that were recorded to have the function of cooling us down, which is related to anti-inflammation in the Western. Macrophage cell lines can be stimulated by LPS (Lipopolysaccharide) and secrete proinflammatory mediators. Thus, it is often used to evaluate the anti-inflammatory effects of different herbs. In our experiment, we also use macrophage cell lines to test different anti-inflammatory effects between chrysanthemum, Job’s tears and grass jelly. In addition, some Chinese herbs such as longan that can parch us are also tested in our experiment. In our results, we found these herbs that are available indeed have ability to anti-inflame in appropriate consistency; however, high dose does harm to cells. In addition, the samples that are poached in ancient ways have better ability to show the low dose of IL-6 and TNF-α. Finally, we would set up a model to test the anti-inflammatory ability of different herbs that were said to be able to cool us down, and then we could test more herbs in the future.

免疫治療的新展望:從一個疾病的動物模式,探討樹突狀細胞的培養與分析

胰島素依賴型糖尿病(insulin-dependent diabetes mellitus; IDDM)是一種胰島素無法正常分泌的自體免疫疾病;而NOD老鼠(non-obese diabetic mouse,NOD)的病徵與其非常相似。藉由觀察NOD老鼠發病前後外顯行為及疑導組織切片的差異,我們認為胰島素依賴型糖尿病的致病機轉是因為T細胞工及胰島組織中製造胰島素的β細胞,使胰島素分泌不足而引起糖尿病;而樹突狀細胞(dendritic cell,DC)是調控淋巴細胞反映的重要調節細胞,未來可望利用樹突狀細胞進行胰島素依賴型糖尿病的免疫調控治療。本實驗即是利用IL-4、GM-CSF使NOD老鼠的骨隨幹細胞分化樹突狀細胞,並藉由控制NOD老鼠的年紀與的數突狀細胞培養天數,希望取得較多的數突狀細胞,以利未來免疫治療之用。Insulin-dependent diabetes mellitus (IDDM) is a spontaneously occurring autoimmune disease in which cellular immune components mediate destruction of the insulin-producing βcells of the pancreas. It begins with an asymptomatic stage during theβcells are gradually destroyed. These patients have to depend on injecting insulin to lower their blood glucose, facing the dander of being infected. So we want to research into the cause of IDDM by model animal- NOD mouse (non-obese diabetic mouse). We observe the differences of exterior behavior and sections of pancreas organization between NOD mice and normal ones. It has been shown that the immunophological mechanism of IDDM is T cells destroy βcells of genetically predisposed individuals and result in insufficiency of insulin-producing. Dendritic cells(DC), having great Ag-presenting ability, are related to IDDM. We cultivate bone marrow stem cells of 5-week-old,8-week-old, and 21-week-old NOD mice treated with IL-4,GM-CSF and make them differentiate into dendritic cells. The result shows that using 8-week-old NOD mice to cultivate will get the largest amount of dendritic cells. We also compare the percentage of differentiated DCs for 6 days’ culture with 9 days’,and we find that 9 days’is better. Dendritic cells are the effect Antigen-presenting cells which can be used for immunotherapy of IDDM , though , its complicated mechanism still needs further researching and developing. We hope in the future IDDM patients could get rid of the suffering of injecting insulin in their whole life.

氧化壓力影響基因轉換表現對脂肪分化之作用

細胞脂肪分化是造成肥胖、骨質疏鬆、和糖尿病的重要前置因素。我們若要維持良好身材又想省去減肥藥的問題,那麼我們必須了解造成脂肪化的原因,才可能擁有好的預防之道。利用人類骨髓間質細胞可以分化成骨質與脂肪等細胞的特性,我們研究氧化壓力對間質細胞\r Ras基因轉換表現後骨質與脂肪分化的影響。結果發現以添加超氧根 (O2-,l5nM)形成氧化壓力,可促進正常Ras基因表現的間質細胞朝骨質分化;相反地,超氧根會促進\r Ras基因突變而不表現的細胞,朝向脂肪分化的現象。進一步研究其作可原理,發現氧化壓力可促進 RaS蛋白質啟動細胞外訊息活化酵素(ERK),接著驅動骨質轉錄因子(CBFA1)表現,再到骨鈣蛋白質與骨結節形成。而抗氧化酵素(超氧根轉化酵素;SOD,5OOU/ml)的作用,可以抑制正常Ras基因細胞氧化壓力下骨質分化的進行;但不能防止氧化壓力促進Ras基因突變細胞,朝向脂肪分化的作用。總結而言:Ras基因的表現與否,是決定脂肪分化的關鍵切換點;也是影響氧化壓力對間質細胞朝骨質分化的樞紐。這種基因與氧化壓力互動影響骨質與脂肪分化的剖析,將有助於提醒人們:使用抗氧化劑來調節抗衰老、肥胖、和美容時,必須是在不同情況和不同基因體質的人,有所不同。 \r Human\r mesenchymal stem cells are able to differentiate into bone, muscle, cartilage or\r fat tissues. Our preliminary study with human mesenchymal cell line (HS-5) showed\r that HS-5 cells could differentiate to bone, cartilage and muscle but not fat cells\r as determined by histochemical staining of phenotypes. We have further studied the\r influence of oxidative stress on the switch between bone and fat cell differentiation.\r Results showed that oxidative stress started with exogenous superoxide, produced\r by the interaction of xanthine oxidase and hypoxanthine, promoted the differentiation\r of osteogenic lineage showing expression of osteocalcin and bone nodule formations.\r The mechanism was investigated and superoxide was found to induce ERK (extracellular\r regulated signal kinase) activation; and then the expression of osteogenic specific\r transcriptional factor (CBFA1). A plasmid containing ras-mutant (Ser 17 Asn) which\r can inactivate the expression of ERK was transfected into the HS-5 cells for studying\r the influence of oxidative stress on ras-mutated mesenchymal cells. Surprisingly,\r it was found that oxidative stress did not promote osteogenesis but it enhanced\r adipogenesis from the ras-mutated HS-5 cells. Further studies indicated that superoxide\r neither induced ERK activation nor CBFA1 expression, but it did enhance expression\r of adipogenic specific transcriptional factor (C/EBPα) and lipoprotein lipase in\r the ras-mutated mesenchvmal cells. Taken together, the study model to induce the\r bone cell differentiation from human mesenchymal stem cells may be employed to make\r bone cells for tissue engineering.

結合奈米金粒與DNA適體的金黃色葡萄球菌快速檢測系統

金黃色葡萄球菌是生活中常見的病原菌之一,因其抗藥性日益嚴重,是大家所熟知的超級細菌。 目前醫院對此菌的檢測方式,從培養到獲得結果大約需要兩天,對許多感染此菌的重症患者是無法接受的醫療時間延誤。 有鑑於此,本研究利用創新的適體、光電及奈米技術發展一個可以快速偵檢金黃色葡萄球菌的系統。 適體為具有與抗體同樣分子辨識功能的寡核酸。我們利用DNA適體篩選技術,獲得能夠專一地辨識金黃色葡萄球菌的適體序列,進一步發展高敏感度細菌檢測系統,並測得靈敏度近個位數的金黃色葡萄球菌。本研究亦結合奈米金與共振光散射原理,以簡便的二極體雷射與偵測裝置,可快速判定檢測樣品中是否有金黃色葡萄球菌,大大縮短檢驗所需的時間。

小鼠骨骼肌細胞分化過程中SMN 基因mRNA剪接型之變化

脊髓性肌內萎縮症為常見之體染色體隱性遺傳性疾病,在台灣罹病率約為萬分之一,罹病者會造成幼兒期致死或因肌肉萎縮導致殘障。大多罹病者致病成因為SMN基因突變,脊髓前角運動神經元凋亡退化,導致上下肢肌肉發生漸進性萎縮

安非他命對小鼠中腦紋狀體之細胞凋亡相關蛋白質表現的影響

安非他命的濫用在台灣是非常嚴重的公眾健康及社會問題。安非他命會導致一連串的行\r 為異常,包括在中腦紋狀體內釋放多巴胺及阻止多巴胺回收來增加使用者的活動力。由於安\r 非他命會對腦細胞造成傷害,本研究的目的為探討低劑量、無立即毒性之安非他命(類似於人\r 類使用習慣)於短期內是否會對老鼠大腦紋狀體內的蛋白質表現有影響。因此利用西方點墨法\r 分析施打低劑量安非他命(2 到6 mg/kg)約一星期之後,C57BL6 小鼠的大腦紋狀體中一些重\r 要蛋白質[包括腺?酸受體A2A-R、第五亞型腺?酸環化?AC5、caspase-8、PARP、NF-κB\r 及血紅素加氧?-1(HO-1)]的表現是否有改變。實驗結果顯示,低劑量安非他命處理對大部分\r 蛋白質的表現並沒有明顯的差異,但在施打安非他命老鼠之大腦紋狀體中,HO-1 有些微但明\r 顯的增加,顯示安非他命可能對腦組織產生氧化性傷害。因此長期使用安非他命對中腦紋狀\r 體是否造成傷害是值得關心及繼續探討的課題。The wide spreading use of amphetamine (AMPH) in Taiwan has become a serious\r public health and social problem. AMPH evokes a series of behavior abnormality including\r enhanced locomotor behavior by releasing dopamine and inhibiting dopamine-uptake in the\r striatum. Since AMPH is known to cause brain damage, the purpose of this study is to\r investigate the expression of several important proteins in the mouse striatum after\r treatment with low and non-toxic dosages of AMPH for a short period (mimicking the\r common usage pattern of humans). C57BL6 mice were daily IP-injected with various doses\r of AMPH (0 to 6 mg/kg) for one week. Expression levels of adenosine receptor A2A-R,\r adenyl cyclase type 5,caspase-8, PARP, NF-κB and heme oxygenase-1 (HO-1) in the\r striatum were analyzed by Western blotting technique. Most proteins examined were not\r affected by the 1-week AMPH treatment, except HO-1. A slight but significant increase of\r HO-1 by AMPH treatment indicated that AMPH may cause oxidative damage in brain.\r These results suggest that the injury induced by long-term AMPH exposure warrants our\r further concerns and investigation.

Automatic Sterilization System for Operating Rooms?

The ASSOR is a device that allow to perform the sterilization function in hospital areas, the most important sectors of the hospital where it is required to implement this type of systems are the operating rooms, intensive cares, baby care, pathology, etc. The principle of the present project is a system that enables or either disables a valve that allows the fluid of the product, antiseptic or sterilizing, inside the room to be sterilized. The main application of this system is, after the manual cleansing of the room, in a control board, the procedure is turned on. The ASSOR consists, in general, of an electro valve that controls the fluid of the antiseptic into the room, a fan system, the electronic control circuit for the application of the product and electronic circuit to have a synchronized control of the system, and finally the product application in the target room.