Oleate metabolism in isolated hepatocytes from lean and obese Zucker rats. Influence of a high fat diet and in vitro response to glucagon

The uptake and metabolism of [1-¹⁴C]oleate (0.3 mmol/L) were studied in isolated hepatocytes from lean and obese Zucker rats fed either a control (low-fat) diet or a high-fat diet. With the control diet, [1-¹⁴C]oleate uptake was increased by 70% in the obese rats, and fat-feeding decreased this uptake to values comparable to that of their lean littermates. Interestingly, the hepatocyte mean surface area was increased in the obese mutants by 21% with the control diet and by 30% with the high-fat diet. The possible reasons for the differences in oleate uptake are discussed. With the control diet, cells from the obese rats showed a four-fold rise in [1-¹⁴C]oleate esterification, while ketogenesis (β-hydroxybutyrate + acetoacetate production) as well as the radioactive acid-soluble products were greatly depressed. Production of CO₂ was very low and similar in both groups of animals. Adaptation to the high-fat diet in the obese rats resulted in a reversal between esterification and oxidation of oleate: the latter became the major metabolic pathway as in the lean rats. The ketogenic capacity was greatly if not completely restored. In the lean animals, glucagon stimulated ketogenesis both in the presence or absence of oleate and decreased [1-¹⁴C]oleate esterification. In the obese rats, the hormone exerted a significant ketogenic effect only if oleate was present and did not influence its esterification. The data demonstrate the following abnormalities in the hepatocytes of obese Zucker rats: (1) an enlargement of cell size, (2) an increased oleate uptake, (3) a virtual absence of a ketogenic response to exogenous oleate, and (4) a markedly increased esterification of the latter. The metabolic defects, but not the cell size, appear to be largely corrected by an adaptation to a high-fat diet. The hepatic response to glucagon was decreased in the obese rats at the level of endogenous ketogenesis.     

七叶一枝花种子萌发不同阶段生理生化变化研究

目的探讨七叶一枝花Paris polyphylla var.chinensis种子萌发不同阶段的酶和内源激素调控机制,为其种子解除休眠、萌发不同阶段采取有效处理措施,提高出苗率提供科学依据。方法通过观察和测定变温层积处理后七叶一枝花种子萌发不同阶段形态差异,采用常规的生理生化方法测定超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、苹果酸脱氧酶(MDH)、6-磷酸葡萄糖脱氢酶(G-6-PDH)5种酶活性,采用质谱定量方法测定吲哚乙酸(IAA)、赤霉素(GA3)、脱落酸(ABA)、水杨酸(SA)、反玉米素(TZ)、茉莉酸(JA)量;研究种子萌发过程中胚率与酶活性和内源激素量变化之间的相关性。结果七叶一枝花种子从未萌动、上胚轴休眠到即将出苗阶段,种子质量和胚率逐步上升;SOD和POD活性逐步升高;CAT和MDH活性逐步减弱,G-6-PDH活性出现双峰,未萌动阶段和萌动后上胚轴未伸长阶段显著高于其他阶段;IAA、GA3、ABA、JA的量逐步升高,IAA和JA量在即将出苗阶段显著高于其他阶段(P0.01);TZ和SA的量先升高后降低,TZ的量在子叶分化形成期和胚乳成熟期显著高于其他阶段(P0.01),SA出苗前期量最高,已萌动胚根刚突破种皮阶段和胚乳形成阶段量次之;CAT酶活性变化与胚率呈显著负相关,IAA和JA的量变化与胚率呈显著正相关。结论CAT对种胚的生长有抑制作用,IAA与JA对种胚的生长有正向促进作用。     

滇重楼内生真菌转化万古霉素的研究

目的 利用滇重楼内生真菌生物转化万古霉素.方法 分离滇重楼内生真菌并筛查它们的生物转化能力.鉴定具有转化能力的内生真菌.结果 有2株内生真菌可以转化万古霉素.经鉴定为产黄青霉和Fusarium nematophilum.菌株G01和G03在添加万古霉素的液体培养基中培养6d后,HPLC （High Performance LiquidChromatography）分析发现,万古霉素的峰面积下降并有新吸收峰出现.结论 内生真菌发酵产生了某些新成分。     

反相高效液相色谱法同时测定重楼药材中4种皂苷的含量

目的建立RP-HPLC法测定重楼中4种甾体皂苷的含量。方法采用色谱柱:Zorbax eclipse XDB C8,(150 mm×4.6 mm,5μm);流动相:乙腈-水(40∶60),流速1.0 ml.min-1;检测波长:203 nm;柱温:40℃。结果4种甾体皂苷范围在0.401~4.028μg线性良好,R=0.999 6~0.999 9,回收率99.1%~103.1%。不同来源的重楼药材中4种甾体皂苷的含量差异较大。结论该方法准确、简捷,为重楼药材的质量控制提供了一定方法和依据。     

Benefits of 3D printing applications in jaw reconstruction: A systematic review and meta-analysis

BackgroundThree-dimensional (3D) printing has changed surgical practice over the past few years, especially in maxillofacial surgery. However, little is known about its real clinical impact. The objectives of our study were to identify clinical outcomes that have been evaluated in the literature regarding 3D printing applications in jaw reconstruction, and to quantify the impact of this technology on operating times.MethodsA systematic review was conducted by searching PubMed and EMBASE to collect comparative studies on 3D printing applications in jaw reconstruction. A meta-analysis of operating times was then performed. A Cochran's Q test was used to determine heterogeneity, and the overall effect size was calculated using a random effects model.ResultsFourteen studies were included in our review. Eighteen clinical end-points were identified, of which the most frequently reported were operating time (n = 5; 35.7%) and the final aesthetic result (n = 4; 28.6%). Operating times were significantly lower in the 3D printing groups, with an overall estimated effect of 21.2% (95% CI 10–33%; p < 0.001).ConclusionThe use of 3D printing in jaw reconstruction was associated with a significant reduction in operating times. The end-points evaluated differed largely among the studies. More studies with higher levels of evidence are needed to confirm our results.     

接种解有机磷细菌对滇重楼光合和生理生化的影响

目的 研究接种不同解有机磷细菌或复合菌对滇重楼叶片光合作用和生理生化特性的影响,为滇重楼的人工栽培找到合适的菌肥提供参考。方法 采用室内盆栽的方式,试验设为空白（CK）、接种Bacillus mycoides（S1）、接种B. wiedmannii（S2）、接种B. proteolyticus（S3）、接种B. mycoides和B. wiedmannii（S4）、接种菌株B. mycoides和B. proteolyticus（S5）、接种B. wiedmannii和B. proteolyticus（S6）、接种B. mycoides、B. wiedmannii和B. proteolyticus（S7）8个处理,观察接种不同解有机磷细菌或复合菌对滇重楼叶片生长发育、光合作用及各项生理生化指标的影响。结果 与空白组比较,处理组中滇重楼叶片的丙二醛含量显著降低（P<0.05）,以S7组最为显著,含量仅为CK组的1/3左右;而叶片的叶面积、光合参数、光合色素含量、可溶性糖、可溶性蛋白、超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性均有不同程度的提高。其中叶面积、可溶性糖和可溶性蛋白含量最高均为S7组,分别是CK组的2.8、2.1、2.2倍;SOD活性最高的为S6组,较CK组增长了2.9倍;POD和CAT活性最高的为S5组,较CK组分别增长了1.5倍和2.1倍。结论 接种不同解有机磷细菌或复合菌能促进滇重楼的生长发育,并提高其对环境的抗逆性。混合接种B. mycoides和B. proteolyticus及3种菌混合接种对滇重楼各方面的影响效果最佳,为滇重楼人工栽培在菌肥选择方面提供了参考依据。