计算法测定肾小球滤过率的临床应用价值

目的 :探讨采用 WCP公式计算方法测定肾小球滤过率 (GFR)的临床应用价值。方法 :采用 99m Tc DTPA清除率测定 6 6例不同疾病住院患者 GFR(Tc GFR) ,并测血清肌酐 (SCr)及尿素氮 (BU N) ,同时以 WCP公式、Robert公式计算 GFR(WCP GFR,Robert GFR) ,以 Cockcroft/ Gault公式计算内生肌酐清除率 (CG CCr) ,所得数据进行对比研究及相关性分析。结果 :除肾功能正常者 CG CCr与 BU N无显著相关外 ,肾功能不全及肾功能正常者的 WCP GFR、Robert GFR、CG CCr均分别与 Tc GFR呈显著正相关(P均 <0 .0 1) ,与 BU N、SCr呈显著负相关 (P<0 .0 1或 P<0 .0 5 ) ;与 Robert GFR、CG CCr比较 ,WCPGFR始终与 Tc GFR最接近 (P均 >0 .0 5 ) ;WCP GFR、Robert GFR、CG CCr与 Tc GFR的平均差绝对值逐渐增大 ,三者间差异显著 (P均 <0 .0 5 )。结论 :WCP GFR、Robert GFR、CG CCr均能在一定程度上准确反映 GFR,而以 WCP GFR更准确 ,且简便、快速、安全而廉价 ,可代替 Tc GFR应用于临床     

血液透析脑型失衡综合征发生机制的研究

目的 探讨血液透析脑型失衡综合征的发生机制。方法 采用急性肾功能衰竭的动物模型,观察血液透析后血浆渗透浓度迅速下降对脑水含量、颅内压、脑脊液生化和酸碱平衡的影响。结果 血液透析使血浆渗透浓度迅速下降,形成明显的脑/血渗透浓度梯度和尿素浓度梯度,使脑水含量明显增加,颅内压显著升高。透析后脑脊液pH下降、碳酸氢根(HCO_3~-)降低、Pco_2升高,与同期血浆相应值比较,差异有显著性意义(P<0.05)。结论 血液透析引起的血浆尿素氮快速下降可以导致脑水增加及颅压增高,其机制主要是由尿素的反向渗透效应引起。     

Synthesis and cytotoxic activity of new alkyl[3-(2-chloroethyl)ureido]benzene derivatives

Several alkyl[3-(2-chloroethyl)ureido] (CEU) benzene derivatives were prepared as potential anticancer agents. These new compounds were readily prepared in good yields by addition of anilines to 2-chloroethylisocyanate. Their cytotoxic activity was evaluated on human breast cancer (MDA-MB-231), human colon adenocarcinoma (LoVo) and mouse lymphocytic leukemia (P388D₁) tumor cell lines. Several new CEUs were significantly more cytotoxic than the nitrogen mustard chlorambucil. The biological activity of these aromatic urea derivatives seems to be related to the nature and position of the alkyl substituents on the aromatic ring. Substitution by branched alkyl groups on position 4 of the aromatic ring led to cytotoxic molecules which are up to 5 times more potent than the standard chlorambucil.     

短期用药对幽门螺杆菌检测结果的影响

目的：研究短期不规则用药对幽门螺杆菌(Hp)检测结果的影响。方法：136名慢性胃炎及消化性溃疡的住院患，根据病史分为服药组即Hp检查前一周内接受过铅剂、抑酸剂治疗的患，共四例。对照组即Hp检查前未接受过药物治疗的患考，共37例。Hp检查方法包括①血清学方法；②快速尿素酶试验(RUT)；③组织学方法；④13c—尿素呼气试验(13C—UBT)。结果：服药组RUT，组织学，13C—UBT方法Hp检出率分别为9．0％，21．2％，27．3％，均显低于对照组相应Hp检出率37．8％、40．5％、48．6％(P＜0．01，P＜0．05，P＜0．05)。两组血清学方法Hp IgG、IgM阳性率各为48．5％，51．5％和54．1％，54．1％(P＞0．05)。单独服用质子泵抑制剂组RUT，组织学方法Hp检出率4．0％，16．0％显低于对照组相应方法Hp检出率(P＜0．01，P＜0．05)。单独服用枸橼酸铋钾、H2受体拮抗剂患中各方法Hp检出率与对照组检出率无显性差异(P＞0．05)。单独服用枸橼酸铋钾、H2受体拮抗剂、质子泵抑制剂三组Hp感染率14．3％、15．0％、16．0％均显低于对照组Hp感染率46．0％(P＜0．05)。结论：Hp检查前短期使用铋剂、抑酸剂可导致Hp检出率下降，短期使用质子泵抑制剂可显降低RUT、组织学方法Hp检出率；各方法中快速尿素酶试验检出率最低。血清学方法检测Hp抗体不受药物影响。     

NPN日粮中添加益生素对绵羊生长性能及消化代谢的影响

选用40只5月龄的杂交绵羊(萨福克×小尾寒羊),随机分为两组,研究了非蛋白氮日粮中添加益生素对绵羊生长性能及消化代谢的影响。对照组饲喂C日粮(2%包被尿素)、试验组饲喂D日粮(2%包被尿素 0.2%益生素)。结果表明:(1)D日粮总增重和日增重要大于C日粮,有增加的趋势;但差异不显著;(2)D日粮能显著提高绵羊的沉积氮和降低尿氮的排出(P<0.05)。两组进食干物质、进食氮、粪氮、可消化氮之间差异不显著(P>0.05);D日粮可以提高沉积氮和可消化氮、沉积氮和进食氮的比例,降低尿氮与进食氮的比例;(3)D日粮可以显著提高绵羊的干物质、ADF的消化率以及酸不容灰分的利用率(P<0.05)。氮表观消化率和NDF消化率差异不显著。本试验结果表明,绵羊非蛋白氮中日粮添加0.2%益生素可以提高绵羊对非蛋白氮的利用率。     

Relationship between cellular ATP content and cellular functions of primary cultured rat hepatocytes in hypoxia

The importance of oxygen in maintaining the functional integrity of hepatocytes has been well established in a variety of experimental models, such as in vivo , perfused liver and isolated hepatocytes. However, one of the shortcomings of these systems is their short life span. Therefore, we have examined the effects of long-term hypoxia on cellular adenine nucleotide content and cellular functions, such as albumin production, urea production and DNA synthesis, in adult rat hepatocytes in primary culture. Hepatocytes were cultured at a density of 11 × 10⁴ and 5 × 10⁴ cells/0.18 mL per cm² for the study of albumin and urea production and DNA synthesis, respectively, at various oxygen tensions (20, 12, 8 and 5%) for 24 h. Cellular ATP content in cultured hepatocytes in hypoxia gradually declined, corresponding to the decrease in oxygen tension, and the cellular ATP level at 5% oxygen was approximately 20% of that at 20% oxygen. Albumin production also decreased in parallel with the decrease in cellular ATP content in cultured hepatocytes in hypoxia. However, even when cellular ATP content gradually declined corresponding with the decrease in oxygen tension in cultured hepatocytes in hypoxia, such as at 8 or 5% oxygen, urea production remained at a high level; in contrast, DNA synthesis was completely suppressed. These results suggest that the cellular ATP content decreases in cultured hepatocytes during long-term hypoxia in relation to oxygen tension and that the relationship between decreased ATP levels and liver function in cultured hepatocytes during hypoxia differs for albumin production, urea production and DNA synthesis.     

区域动脉插管注射尿素治疗头面部血管瘤

本文报道6例头面部血管瘤采用区域动脉插管注射尿素治疗。其中3例单用尿素治愈。3例结合外科手术治愈。最后讨论尿素治疗的机理及优点。     

Identification of 16 novel mutations in the argininosuccinate synthetase gene and genotype-phenotype correlation in 38 classical citrullinemia patients

Classical citrullinemia (CTLN1), a rare autosomal recessive disorder, is caused by mutations of the argininosuccinate synthetase (ASS) gene, localized on chromosome 9q34.1. ASS functions as a rate-limiting enzyme in the urea cycle. Previously, we identified 32 mutations in the ASS gene of CTLN1 patients mainly in Japan and the United States, and to date 34 different mutations have been described in 50 families worldwide. In the present study, we report ASS mutations detected in 35 additional CTLN1 families from 11 countries. By analyzing the entire coding sequence and the intron-exon boundaries of the ASS gene using RT-PCR and/or genomic DNA-PCR, we have identified 16 novel mutations (two different 1-bp deletions, a 67-bp insertion, and 13 missense) and have detected 12 known mutations. Altogether, 50 different mutations (seven deletion, three splice site, one duplication, two nonsense, and 37 missense) in 85 CTLN1 families were identified. On the basis of primary sequence comparisons with the crystal structure of E. coli ASS protein, it may be concluded that any of the 37 missense mutations found at 30 different positions led to structural and functional impairments of the human ASS protein. It has been found that three mutations are particularly frequent: IVS6-2A>G in 23 families (Japan: 20 and Korea: three), G390R in 18 families (Turkey: six, U.S.: five, Spain: three, Israel: one, Austria: one, Canada: one, and Bolivia: one), and R304W in 10 families (Japan: nine and Turkey: one). Most mutations of the ASS gene are "private" and are distributed throughout the gene, except for exons 5 and 12-14. It seems that the clinical course of the patients with truncated mutations or the G390R mutation is early-onset/severe. The phenotype of the patients with certain missense mutations (G362V or W179R) is more late-onset/mild. Eight patients with R86H, A118T, R265H, or K310R mutations were adult/late-onset and four of them showed severe symptoms during pregnancy or postpartum. However, it is still difficult to prove the genotype-phenotype correlation, because many patients were compound heterozygotes (with two different mutations), lived in different environments at the time of diagnosis, and/or had several treatment regimes or various knowledge of the disease.     

Dialysate-side urea kinetics. Neural network predicts dialysis dose during dialysis

Determination of the adequacy of dialysis is a routine but crucial procedure in patient evaluation. The total dialysis dose, expressed as Kt/V, has been widely recognised to be a major determinant of morbidity and mortality in haemodialysed patients. Many different factors influence the correct determination of Kt/V, such as urea sequestration in different body compartments, access and cardiopulmonary recirculation. These factors are responsible for urea rebound after the end of the haemodialysis session, causing poor Kt/V estimation. There are many techniques that try to overcome this problem. Some of them use analysis of blood-side urea samples, and in recent years, on-line urea monitors have become available to calculate haemodialysis dose from dialysate-side urea kinetics. All these methods require waiting until the end of the session to calculate the Kt/V dose. In this work, a neural network (NN) method is presented for early prediction of the Kt/V dose. Two different portions of the dialysate urea concentration-time profile (provided by an on-line urea minitor) were analysed: the entire curve A and the first half B, using an NN to predict the Kt/V and compare this with that provided by the monitor. The NN was able to predict Kt/V is the middle of the 4h session (B data) without a significant increase in the percentage error (B data: 6.69%±2.46%; A data: 5.58%±8.77%, mean±SD) compared with the monitor Kt/V.