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摘要：目的 建立肉及肉制品中 (EPEC) 的快檢方法。
方法 以 EPEC 特異的微絨毛粘連基因 (eae gene) 和菌毛束形成編碼基因 (bfp gene) 作為模板，設計兩對引物對肉及肉制品中的 EPEC 進(jìn)行特異性擴增。
結果 該方法特異性好，對肉及肉制品中 EPEC 的最低檢出量為 10cfu/g ，檢出時(shí)間為 8 ～ 17 小時(shí)。
結論 建立了可檢測肉及肉制品中 EPEC 的快速、敏感、特異 PCR 方法。
關(guān)鍵詞：兩重 PCR 肉及肉制品 腸致病性大腸桿菌
中圖分類(lèi)號： R155 . 55 TS207 . 4 文獻標識碼： A
Development of methods on detection of enteropathogenic escherichia coli by double PCR in meat and meat product
Shi Yun, Li Ye - peng, Ji Rong
Institute of Disease Control and Prevention, Acadimy of Military Medical Sciences, Beijing 100039, China
Abstract ： Objective To establish a rapid method for detecting Enteropathogenic Escherichia coli EPEC) in meat and meat product. Methods Based on attaching and effacing lesion ( eaeA gene) and bundle orming pili ( bfpA gene) of EPEC, two pairs of primers were designed. Then EPEC in meat and meat product were detected by double PCR. Results The method is rapid and specific. The limit of detection is 10cfu/g in 8-17hours. Conclusion\ A simple, rapid, sensitive and specific PCR method can be established to detect EPEC in meat and meat product.
Key words:double PCR ， meat and meat product ， Enteropathogenic Escherichia coli
基金項目：國家科技部十五攻關(guān)重大項目課題 (No.2001BA 804A 03)
作者簡(jiǎn)介：史云，女，博士
1 中國疾病預防控制中心營(yíng)養與食品安全所
用雙標穩定同位素技術(shù)分析乳糖酶缺乏者小腸粘膜乳糖酶活性
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鐘燕 黃承鈺 1 陰文婭 Vonk RJ 2
四川大學(xué)華西公共衛生學(xué)院，成都 610041 1 |
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摘要：目的 應用雙標穩定同位素 13 C - 乳糖 / 2 H - 葡萄糖負荷試驗對乳糖酶缺乏者小腸粘膜乳糖酶活性進(jìn)行定量分析。
方法 選用 43 名乳糖酶缺乏者 ( 呼氣 Δ H 2 濃度 >20 μ mol/mol) 作為實(shí)驗對象，根據乳糖不耐受癥狀記錄分為乳糖吸收不良組 (LM) 和乳糖不耐受組 (LI) 。以 25g 13 C - 乳糖和 0 . 5g 2 H - 葡萄糖作為受試底物，分析受試者攝入底物之后各時(shí) 點(diǎn)血漿中總葡萄糖、 13 C - 葡萄糖和 2 H - 葡萄糖濃度，并計算各時(shí)點(diǎn) 13 C - 葡萄糖 / 2 H - 葡萄糖吸收百分率的比值，以 45min 、 60min 、 75min 三個(gè)時(shí)點(diǎn)所得比值的均值作為乳糖消化指數 (LDI) 來(lái)反應小腸乳糖酶活性。
結果 乳糖吸收不良組和乳糖不耐受組兩組各時(shí)點(diǎn)血漿總葡萄糖、 13 C - 葡萄糖無(wú)顯著(zhù)性差異 ，乳糖吸收不良組的乳糖消化指數顯著(zhù)高于乳糖不耐受組 (0 . 47 ± 0 . 15 vs 0 . 34 ± 0 . 14) ；乳糖消化指數與 6h 累積 H 2 呼出量無(wú)顯著(zhù)性相關(guān)關(guān)系 (r=0 . 12, P=0 . 46) ；經(jīng) H 2 呼氣試驗結果判定為乳糖酶缺乏的個(gè)體，經(jīng) 13 C - 乳糖 / 2 H - 葡萄糖負 荷試驗分析顯示小腸粘膜仍存在一定乳糖酶活性。結論 采用雙標穩定同位素 13 C - 乳糖 / 2 H - 葡萄糖負荷試驗可以準確、靈敏 地定量分析小腸粘膜乳糖酶活性，同時(shí)可以計算體內乳糖消化量。
關(guān)鍵詞：乳糖酶缺乏 穩定同位素 13 C - 乳糖 / 2 H - 葡萄糖 負荷試驗
中圖分類(lèi)號： Q533 . 3 Q591 . 4
文獻標識碼： A
Analysis of lactase activities of small intestine mucous membrane by double labeled stable isotope technique in subjects with lactase deficiency
Zhong Yan, Huang Cheng - yu, Yin Wen - ya, Vonk RJ
Department Huaxi School of Public Health, Sichuan University , Chengdu 610041, China
Abstract ： Objective Low lactase activity in small intestine mucosa is the main reason for the occurrence of lactose malabsorption (LM) and lactose intolerance (LI). It would be the basis for the research on LM and LI to find an accurate method to analyze the activity of lactase. Mehtods In this study, 43 volunteers were selected and divided into LM and LI group according to the results of H 2 breath test and symptoms record. Twenty five grams of 13 C - lactose and 0 . 5g 2 H - glucose in 250ml solution were consumed by all the volunteers. The concentration of total plasma glucose, 13 C - glucose and 2 H - glucose were measured, the ratio of ［ 13 C - glucose ］ / ［ 2 H - glucose ］ and lactose digestion index (LDI)were calculated which could reflect the lactase activities in the mucous membrane of small intestine. Results It was found that there was no significant difference in the concentration of total glucose and 13 C - glucose, while the LDI in LM group (0 . 47 ± 0 . 15) was significantly higher than LI group (0 . 34 ± 0.14). There was no significant relationship between LDI and 6h cumulative breath H 2 amount (r=0 . 12, P=0 . 46). The 13 C - lactose/ 2 H-glucose challenged test showed there was still residual lactase activity in small intestine.Conclusion It was concluded that 13 C - lactose/ 2 H - glucosetest can accurately and sensitively determine the lactase activity on small intestinal mucous membrane and digestible lactose amount.
Key words:lactose deficiency, stable isotopes, 13 C - lactose/ 2 H - glucose challenged test
基金項目：國家自然科學(xué)基金資助項目 (No. 30271126)
作者簡(jiǎn)介：鐘燕，女，博士，現為第二軍醫大學(xué)長(cháng)海醫院臨床營(yíng) 養 博士后
1 通訊作者
2 Groningen 大學(xué)，荷蘭
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維生素 A 和鋅聯(lián)合在體外誘導人外周血單核細胞 DNA 損傷的研究
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李婷欣 李云 1 鹿子龍
四川大學(xué)華西公共衛生學(xué)院，成都 610041 |
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摘要：目的 通過(guò)堿性單細胞電泳凝膠技術(shù)和流式細胞術(shù)，研究維生素 A 和鋅聯(lián)合在體外誘導人的外周血單核細胞 (PBMC)DNA 的損傷。
方法 分離健康人 PBMC 在體外培養，分別加入不同劑量的維生素 A 和鋅改變培養基環(huán)境，通過(guò)單細胞電泳凝膠技術(shù)和流式細胞術(shù)，分別檢測各個(gè)劑量組 PBMC 的細胞凋亡率與 DNA 斷裂情況。結果 體外培養時(shí)補充適量的鋅和維生素 A 尚未使 PBMC 凋亡率增加，沒(méi)有加重 DNA 損傷，但同時(shí)補充過(guò)量的鋅和維生素 A 就會(huì )引起 PBMC 的廣泛凋亡和嚴重的 DNA 損傷（ P<0 . 05 ），且比由于維生素 A 或鋅單獨過(guò)量引起的損傷更嚴重。當維生素 A 過(guò)量時(shí)，補充適量鋅對已損傷的細胞有一定的修復作用，但可能會(huì )擴大受損的細胞范圍；當鋅過(guò)量時(shí)，補充適量維生素 A 對正常細胞有一定的保護作用，但可能會(huì )加劇已受損細胞的損傷程度。
結論 在體外試驗中，過(guò)量的補充維生素 A 和鋅可能會(huì )造成人的 PBMC 的 DNA 單鏈嚴重損傷，具體機理尚須進(jìn)一步研究。
關(guān)鍵詞：維生素 A 鋅 單核細胞 DNA 損傷 彗星試驗 流式細胞術(shù) 細胞凋亡
中圖分類(lèi)號： Q562 Q581 R151 . 2 文獻標識碼： A
Combination effects of vitamin A and zinc on human's
PMBC DNA damage in vitro
Li Ting - xin, Li Yun,Lu Zi - long
West China School of Public Health, Sichuan University , Chengdu 610041, China
Abstract ： Objective To study the combination effects of vitamin A (Vit.A) and zinc on human's PBMC DNA damage in vitro. Methods The PBMC from healthy volunteer was purification and cultured in the basic culture medium with Vit.A of 10 -4 , 10 -5 and 10 -6 mol/L, or/and with Zn of 10 -6 , 10 -5 , 10 -4 and 10-3mol/L. The basic culture medium with K 2 Cr 2 O 7 of 1mmol/L was the male control. The damage of PBMC DNA was respectively examined by SCGE and the image analyzer measured the comet tail rate and length. The apoptosis of each group PBMC was detected by FCM. Results The overdose supplement of zinc and Vit.A can damage the PBMC DNA in vitro culture (P<0 . 01), while the suitable supplement doesn't find. When the Vit.A supplement has been excessive, giving suitable zinc could repair the damage of DNA, but would expand the injured cell. While when the zinc supplement has been excessive, giving suitable Vit.A could protect the healthy cells, but would aggravate the damage degree of injured cell. Conclusion In vitro culture, the overdose Vit.A and zinc supplement could damage the human's PBMC DNA significantly. This need more researches to provide.
Key words:vitamin A, zinc, PBMC, DNA damage, SCGE, apoptosis, FCM
基金項目：國家自然科學(xué)青年基金資助 (No.39600122)
作者簡(jiǎn)介：李婷欣，女，碩士研究生
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