视黄酸及干扰素对胃癌细胞系MKN45中p16,p21,c-myc基因表达的影响

目的探讨全反式视黄酸及干扰素两种因子对胃癌MKN45细胞的影响.方法将视黄酸及干扰素同时加入胃癌细胞系MKN45中进行细胞培养,用MTT法测定细胞的生长状况,并通过Northern blot和免疫组化测定p16,p21及c-myc的表达情况.结果干扰素（IFN）协同全反式视黄酸（ATRA）可有效地抑制MKN45细胞生长,癌细胞经联合用药诱导后p16和p21基因的表达水平提高,c-myc基因表达水平下降.视黄酸受体RARα基因在MKN45细胞中呈低水平表达,经ATRA和IFN诱导后表达水平提高.结论 ATRA联合IFN诱导可调节p16和p21基因的表达水平,抑制胃癌MKN45细胞生长,这可能与细胞中RARα基因高水平表达有一定关系.     

Differential responses in anterior pituitary luteinizing hormone (LH) content and LHβ- and α-subunit MRNA, and plasma concentrations of LH and testosterone, in bulls treated with the LH-releasing hormone agonist deslorelin

Anterior pituitary gland contents of LH and LHß- and α-subunit mRNAs, and circulating concentrations of LH and testosterone, were determined in bulls treated with the LH-releasing hormone (LHRH) agonist deslorelin. Brahman (Bos indicus) bulls (14-month-old) were allocated to two groups and received the following: Control (n = 5), no treatment; Deslorelin (n = 4), four deslorelin implants (approximately 200 μg total deslorelin/day) for 36 d. Plasma concentrations of LH were higher in bulls treated with deslorelin on Day 1, had returned to typical levels by Day 8, and did not differ for control bulls and bulls treated with deslorelin from Day 8 to Day 29. Pituitary content of LH on Day 36 was reduced (P < 0.001) in bulls treated with deslorelin (33 ± 4 ng/mg) compared with control bulls (553 ± 142 ng/mg). Relative pituitary content of LHß-subunit mRNA was also reduced on Day 36 in bulls treated with deslorelin (Control, 0.65 ± 0.10; Deslorelin, 0.22 ± 0.04; P = 0.003). However, α-subunit mRNA relative content did not differ (Control, 0.73 ± 0.15; Deslorelin, 1.06 ± 0.12; P > 0.05). Plasma concentrations of testosterone were increased over the period of the experiment in the bulls treated with deslorelin compared with control bulls. This is the first demonstration of reduced pituitary content of LHß-subunit mRNA and LH, and unaltered content of α-subunit mRNA, in bulls treated with LHRH agonist. This was associated with apparently typical plasma concentrations of LH and elevated plasma testosterone. The anterior pituitary in bulls treated with LHRH agonist, therefore, undergoes classical desensitization and downregulation, but plasma LH and testosterone are not suppressed.     

海拨高度与肉鸡腹水征的相关性研究

选择云南省海拔高度76．4m～3200m不同的5个地、县自然发生的肉鸡腹水综合征（ASB）与同品种的健康鸡进行对比研究。结果证实,同品种肉鸡喂同种饲料并在相同的饲养管理条件下,无论在低海拔地区还是高海拔地区发病相同,肉鸡腹水综合征的发生与海拔高低无关。     

Relative bio-availability and utilisation of phosphatic fertilisers as sources of phosphorus in broilers and layers

1. Different concentrations of non-phytate phosphorus (NPP, 2.5, 3.0, 3.5, 4.0 and 4.5 g/kg diet) were given to broilers (8 to 42 d of age) to establish regressions between dietary NPP concentration and body weight gain and tibia ash content. Second and third experiments were conducted to study the feasibility of utilisation of different phosphatic fertilisers [ammonium phosphate (AP), ammonium polyphosphate (APP), single super phosphate (SSP), NPK (17:17:17, NPK) and NP (28:28:0, NPK)] in commercial broilers (8 to 42 d) and White Leghorn layers (252 to 364 d). 2. Phosphatic fertilisers were incorporated both in broiler (10 g calcium and 4.5 g NPP/kg) and layer (35 g calcium and 3.5 g NPP/kg) diets by replacing dicalcium phosphate (DCP) in toto. 3. The logarithmic curves obtained for predicting the body weight gain and tibia ash content at different levels of NPP used in experiment 1 were Y = 156.27 + 2,468.8 logX (r2= 0.958) and Y = 530.82 + 144.26 log X (r2 = 0.916), respectively. 4. Body weight gain and food intake in broilers given APP- or NP-supplemented diets were comparable to these in the DCP-fed group. Feeding of NPK, AP or SSP resulted in significant depression in weight gain and food intake and high excreta moisture content. Food/gain, Ca and P contents in tibia ash and serum were not influenced by the use of phosphatic fertilisers as P sources in broiler diets. 5. Tibia ash content in broilers fed on diets containing fertilisers was either similar to or significantly higher than that in the DCP-fed group. Broilers on AP or SSP retained more P and had higher tibia ash content than those on DCP. AP, SSP or NPK caused degenerative and necrotic changes in liver, kidney and intestine of broilers. 6. Relative bio-availability of P from APP or NP was better for body weight gain than AP, SSP or NPK, while the reverse was true for bone calcification. 7. APP and NP gave hen-d egg production similar to that of DCP-fed layers. Food intake was significantly reduced in layers fed on diets containing fertilisers. However, food/egg mass, egg weight and serum Ca and inorganic P contents were not influenced by inclusion of fertilisers in layer diets. 8. Except for AP, inclusion of fertilisers in layer diets reduced shell weight and shell thickness compared with the DCP-fed group. However, no apparent eggshell defects were found which could be attributable to diet. 9. Results of these experiments suggest that APP and NP can be used as the sole source of P both in broiler and layer diets, replacing DCP in toto. However, when utilising these P sources in layers, due attention should be given to shell quality. Fertilisers containing high F (AP and SSP) or K (NPK) reduced performance in broilers and layers and caused microscopic changes in liver, kidney and intestine in broilers.     

利用质量控制图监控不同实验条件对布鲁氏菌试管凝集实验结果的影响

运用建立的质量控制图,监控不同实验条件对布鲁氏菌试管凝集实验结果可能造成的影响。在每次日常检测时对标准阳性血清进行试管凝集实验并使用浊度仪测量其上清液的光密度(OD值),在收集足够有效数据后,绘制当前条件下的质量控制图。通过模拟日常实验条件下孵育温度、时间等容易产生偏离的条件,记录不同实验条件下标准阳性血清试管凝集实验后上清液的OD值,绘制控制用控制图。运用绘制的质量控制图对不同实验条件进行监控,发现孵育温度和孵育时间均对实验结果产生较大影响,从而导致失控。采用质量控制图对布鲁氏菌试管凝集实验进行监控,可提高质量监控的有效性、科学性。严格控制实验条件是保证实验结果的重要前提。