Evaluation of the Vickers D300 for routine analysis of urea, bilirubin, total protein and albumin in plasma

The Vickers D300 analyser was tested using the manufacturer's recommended methods for urea, bilirubin, total protein and albumin. Precision, “accuracy”, correlation with the existing laboratory procedures, and carry over were evaluated. The results indicated that the machine was a valuable addition to the equipment of a routine Chemical Pathology laboratory.     

The effect of different buffers and amounts of intestinal alkaline phosphatase isoforms on total alkaline phosphatase activity

BACKGROUND: The transphosphorylating accepter buffers (2-amino-2-methyl-1-propanol, AMP; N-methyl-D-glucamine, MEG; diethanolamine, DEA and 2-ethylaminoethanol, EAE) have been widely used for the measurement of serum total alkaline phosphatase activity (ALP) in clinical laboratories, and the individual isozyme are activated differently by respective buffers. MATERIALS AND METHODS: We examined the activity of serum ALP using four buffers with levels of both high molecular weight intestinal alkaline phosphatase (HIAP) and normal molecular weight intestinal alkaline phosphatase (NIAP). We classified 80 healthy subjects into two groups of blood group B or O secretors (n=36) and other blood groups (n=44). RESULTS: The mean ALP activities at fasting in blood group B or O secretors from AMP, MEG, DEA and EAE methods were 15.5%, 24.0%, 11.0% and 22.1% higher than those in other blood groups, respectively. The reference ranges of ALP activity at fasting with the AMP method in blood group B or O secretors and other blood groups were 63.5+/-17.4 U/l (mean+/-S.D.) and 55.0+/-14.5 U/l (mean+/-S.D.), respectively. The difference between the reference ranges of ALP activity in blood group B or O secretors and other blood groups was statistically significant (p<0.01). HIAP and NIAP in serum at fasting only appeared in blood group B or O secretors, and the activities of HIAP and NIAP were 4.7+/-3.4 U/l (mean+/-S.D.) and 2.2+/-1.2 U/l (mean+/-S.D.), respectively. The activity of ALP-(HIAP+NIAP) in blood group B or O secretors was 56.6+/-15.1 U/l (mean+/-S.D.), and this reference range was approximately the same as the ALP activity (55.0+/-14.5 U/l) of other blood groups. The same results were observed with MEG, DEA and EAE methods. CONCLUSIONS: These results suggested that the differences in ALP activity in blood group B or O secretors and other blood groups were closely related to the HIAP and NIAP levels.     

新生儿血清胆红素总量与血浆白蛋白比值对胆红素脑损伤的预测作用

目的：探讨胆红素总量和血浆白蛋白量的比值与神经行为评分之间的关系及在预测胆红素脑损伤中的作用.方法：选择2003-01/2004-12南阳市第一人民医院儿科收治,胆红素总量＞205μmol/L的足月新生儿56例,以同期妇产科出生胆红素总量＜205 μmol/L的正常足月新生儿50例为对照组.所有新生儿在入院时及黄疸消失时进行两次新生儿行为神经测定（20项,每项0～2分,总分40分,＜37分为异常）评估其行为,同时测定血清总胆红素值、白蛋白量,并进行直线相关分析血清胆红素的总量和白蛋白的比值、血清胆红素与行为神经评分的相关性.结果：按意向处理分析,106例患儿全部进入结果分析.[1]新生儿行为神经测定评分结果：治疗前高胆红素组低于对照组（37.80&;#177;2.10,39.20&;#177;0.8,t=4.43,P＜0.01）;治疗后两组无差异（P＞0.05）.[2]胆红素总量/血浆白蛋白量：治疗前高胆红素组高于对照组[（5.54&;#177;1.45）&;#215;10^-3,（3.56&;#177;1.29）&;#215;10^-3,t=6.82,P＜0.01],治疗后两组无差异（P＞0.05）.[3]胆红素总量/白蛋白和行为神经评分相关性：直线相关分析显示两者之间有高度负相关关系（r=-0.97,P＜0.01）,直线回归显示存在着回归关系（回归方程y=42.17-0.79 X,回归系数为-0.79,P＜0.01）.高胆红素组患儿当神经行为评分＜37分时胆红素/白蛋白为6.54&;#215;10^-3.[4]血清胆红素总量和行为神经评分的相关性：直线相关分析显示两者之间无明显的相关性（r=-3.5,P＞0.05）.结论：在预测神经毒性方面,胆红素总量/白蛋白较胆红素的量更准确、更直接.对于高胆红素血症足月新生儿当胆红素总量和白蛋白的比值达到6.54&;#215;10^-3时,应引起高度的重视并积极采取重要措施.     

新生儿血清胆红素总量与血浆白蛋白比值对胆红素脑损伤的预测作用

目的:探讨胆红素总量和血浆白蛋白量的比值与神经行为评分之间的关系及在预测胆红素脑损伤中的作用。方法:选择2003-01/2004-12南阳市第一人民医院儿科收治,胆红素总量>205μmol/L的足月新生儿56例,以同期妇产科出生胆红素总量<205μmol/L的正常足月新生儿50例为对照组。所有新生儿在入院时及黄疸消失时进行两次新生儿行为神经测定(20项,每项0～2分,总分40分,<37分为异常)评估其行为,同时测定血清总胆红素值、白蛋白量,并进行直线相关分析血清胆红素的总量和白蛋白的比值、血清胆红素与行为神经评分的相关性。结果:按意向处理分析,106例患儿全部进入结果分析。①新生儿行为神经测定评分结果:治疗前高胆红素组低于对照组(37.80±2.10,39.20±0.8,t=4.43,P<0.01);治疗后两组无差异(P>0.05)。②胆红素总量/血浆白蛋白量:治疗前高胆红素组高于对照组犤(5.54±1.45)×10-3,(3.56±1.29)×10-3,t=6.82,P<0.01犦,治疗后两组无差异(P>0.05)。③胆红素总量/白蛋白和行为神经评分相关性:直线相关分析显示两者之间有高度负相关关系(r=-0.97,P<0.01),直线回归显示存在着回归关系(回归方程Y=42.17-0.79X,回归系数为-0.79,P<0.01)。高胆红素组患儿当神经行为评分<37分时胆红素/白蛋白为6.54×10-3。④血清胆红素总量和行为神经评分的相关性:直线相关分析显示两者之间无明显的相关性(r=-3.5,P>0.05)。结论:在预测神经毒性方面,胆红素总量/白蛋白较胆红素的量更准确、更直接。对于高胆红素血症足月新生儿当胆红素总量和白蛋白的比值达到6.54×10-3时,应引起高度的重视并积极采取重要措施。     

The effect of reduction in blood volume on plasma renin activity in man.

1. The blood volume was reduced by approximately 10% in nine adult humans. 2. Plasma renin activity was measured before and at intervals after the venesection. In seven subjects there was no significant change. In two subjects there was a slight but significant increase in plasma renin activity. 3. It is concluded that reduction in blood volume is not a major short-term factor in regulating renin production in humans.     

The contribution of endogenous urea to faecal ammonia in man, determined by 15N labelling of plasma urea

To establish the role of endogenous urea as a source of faecal ammonia, the plasma urea of two healthy men was labelled with 15N at a constant level for several days and its 15N enrichment was compared with that of faecal ammonia and total nitrogen. Faeces collected after one complete gastrointestinal transit from the onset of plasma labelling had ammonia 15N enrichments which were only 8.5 +/- 1.2% and total nitrogen enrichments which were 6.8 +/- 0.7% of the plasma urea 15N enrichment. These results show that endogenous urea is not the main precursor of faecal ammonia, which is probably derived by bacterial deamination from the protein of dietary residues, intestinal secretions and shed epithelial cells. The minor contribution of endogenous urea to faecal ammonia suggests that the lumen of the large bowel is not the main site of endogenous urea hydrolysis. The similar labelling of faecal total nitrogen and ammonia nitrogen supports other evidence that these faecal nitrogen fractions are in a constant state of exchange.     

The influence of ABO blood groups, secretor status and fat ingestion on serum alkaline phosphatase

Two experiments have been performed in an attempt to clarify the relationship between liver and intestine alkaline phosphatase iso-enzymes and ABO blood group and secretor phenotype.     

Changes in plasma volume, in transcapillary escape rate of albumin and in subcutaneous blood flow during hypoglycaemia in man

Hypoglycaemia was induced by insulin injected intravenously (0.15 i.u./kg body weight) in seven healthy young males. Plasma volume was measured before and during hypoglycaemia by intravenous injection of 125I before hypoglycaemia and of 131I during hypoglycaemia. Plasma volume decreased and transcapillary escape rate increased significantly during hypoglycaemia. Skin temperature and local subcutaneous adipose tissue blood flow were measured in four different regions. Both tended to decrease during hypoglycaemia and decreased significantly 2 h after hypoglycaemia. There was no correlation between changes in the two measurements, suggesting that there is no simple relationship between subcutaneous blood flow and skin temperature during hypoglycaemia.     

Displacement effect of ceftriaxone on bilirubin bound to human serum albumin

The effects of ceftriaxone, a 'third-generation' cephalosporin, on bilirubin-serum albumin complexes were investigated. This study was performed on human adult samples at various bilirubin-albumin ratios. Ceftriaxone caused a decrease of unconjugated bilirubin and simultaneously an increase of erythrocyte-bound bilirubin. These variations were proportionally more important for low concentrations of antibiotic, including therapeutic values. It was concluded that ceftriaxone competes with bilirubin and displaces it from albumin-binding sites.     

Effect of isoenzyme composition on Kodak Ektachem test results for creatine kinase, lactate dehydrogenase, alkaline phosphatase, and amylase.

Seventy-four patients' sera containing macroenzymes or other uncommon enzyme forms were analyzed for total creatine kinase, lactate dehydrogenase, alkaline phosphatase, or amylase activity on an Ektachem 700XR analyzer. The Ektachem test results correlated well with activities obtained by means of liquid reagents on RA-1000. For each enzyme tested, linear-regression analysis yielded data comparable with those for sera containing exclusively the more common isoenzymes. Increased concentrations of intestinal ALP, however, resulted in higher activities of total ALP being reported for the Ektachem.