Certification of the mass concentration of creatine kinase isoenzyme 2 (CK-MB) in the reference material BCR 608.

We describe the certification of a mass concentration value in the already prepared creatine kinase-2 reference material (BCR 608). Creatine kinase-2 was purified from human heart. The purified enzyme was diluted in order to measure its protein concentration by the Doetsch method. A protein concentration value of 124.30+/-13.17 mg/l was assigned to the stock solution of purified creatine kinase-2. This stock solution was diluted in 25 mmol/l piperazine-N,N'-bis[2-ethanesulfonic acid] (PIPES) pH 7.2, containing 2 mmol/l ADP, 5 mmol/l 2-mercaptoethanol, 154 mmol/l sodium chloride and 50 g/l human albumin to obtain a stable liquid standard of known creatine kinase-2 mass concentration (80.36 microg/l). This standard was then used to recalculate the creatine kinase-2 mass concentration measured in the BCR 608 material by immunoassay. The mass concentration of creatine kinase-2 in samples of reconstituted BCR 608 was certified to be 93.30+/-9.65 microg/l.

Comparative study of a microporous cholestyramine analogue (filicol) and gemfibrozil for treatment of severe primary hypercholesterolemia. Short- and long-term results.

The hypolipidemic effect of gemfibrozil in severe hypercholesterolemia is not well established. Fifty patients with primary hypercholesterolemia (including 18 patients with familial hypercholesterolemia) and stable low-density lipoprotein cholesterol levels greater than 3.90 mmol/L (greater than 150 mg/dL) (6.10 +/- 1.30 [SD] mmol/L; 236 +/- 50 mg/dL) while on a hypolipidemic diet were assigned to treatment for 12 weeks with either 9 g/d of filicol, a microporous cholestyramine analogue, or 1.2 g/d of gemfibrozil in a randomized clinical trial. Tolerance was good with both drugs. Filicol and gemfibrozil caused similar decrements of total cholesterol (14% for both), low-density lipoprotein cholesterol (20% and 18%, respectively), and apolipoprotein B (16% and 21%, respectively). Close to 40% of the patients had decreases of greater than 25% in low-density lipoprotein cholesterol levels with both drugs. Gemfibrozil, but not filicol, significantly increased plasma high-density lipoprotein cholesterol (16%) and apolipoprotein A-I (17%) levels and reduced triglyceride levels (35%). No loss of efficacy was observed with either drug in subsets of patients who had a good 12-week response rate and had extended therapy for up to 12 months. This study demonstrates that gemfibrozil may have a beneficial effect on all aspects of the plasma lipid profile in patients with severe hypercholesterolemia, a clinical situation where it can be used with potential advantages over standard doses of anion-exchange resins.

[Excessive intake of fats and cholesterol in hypercholesterolemic individuals. Effects of dietary intervention on plasma lipids and lipoprotein cholesterol]. / Ingesta excesiva de grasas y colesterol en individuos hipercolesterolémicos. Efectos de la intervención dietética sobre los lípidos plasmáticos y colesterol lipoproteico.

Preliminary evidences suggest that both the frequency of ischemic heart disease and the plasma cholesterol levels are increasing in the Spanish population, whose dietary habits are becoming progressively "westernized". In the present work we used the food frequency method to evaluate the dietary habits of 30 hypercholesterolemic subjects. These and another 65 free-living individuals of both sexes, ages 18-77 yrs, with plasma cholesterol 301 +/- 41 mg/dl or 7.80 +/- 1.06 mmol/l (means +/- SD) were submitted to a hypolipidemic diet similar to the mediterranean diet in order to assess effects on plasma lipids and lipoprotein cholesterol. The usual diet contained (% kcal/day): total fat 37, saturated fat (S) 12, monoinsaturated fat 16 and poliinsaturated fat (P) 6, with P/S = 0.5 and a daily cholesterol intake of 506 mg. During dietary intervention, respective changes were: -7%, -5%, -1%, +2%, +0.6, and -304 mg. After a 3 - month dietary period, significant (p less than 0.001) decreases occurred in total plasma cholesterol (-40 mg/dl or -1.04 mmol/l, -14%), LDL-cholesterol (-35 mg/dl or -0.91 mmol/l, -16%) and triglycerides (-5 mg/dl or -0.28 mmol/l, -14%), while HDL-cholesterol and body weight did not change. Similar effects were obtained when diet was continued for 1 yr in a subgroup of 40 individuals. The responses of plasma cholesterol to dietary change had a normal distribution, with 17% hyporresponses and 15% hyperresponses. A marked decrease (-36%) of plasma triglycerides was observed in 12 subjects with IIb hyperlipidemia. The total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios improved in both men and women.(ABSTRACT TRUNCATED AT 250 WORDS)

Prostaglandin precursor fatty acids in cirrhosis with ascites: effect of linoleic acid infusion in functional renal failure.

1. Functional renal failure (FRF) in cirrhosis with ascites could be related to an inappropriately low renal prostaglandin (PG) production. To investigate whether the impaired renal PG synthesis in these patients is related to a PG precursor fatty acid deficiency, serum levels of linoleic and arachidonic acids and the urinary excretion of PGE2, 6-keto-PGF1 alpha and thromboxane B2 (TxB2) were measured in 10 normal subjects, 17 non-azotaemic cirrhotic patients with ascites and 10 cirrhotic patients with ascites and FRF. 2. Serum linoleic acid levels were similar in the three groups studied. Both groups of cirrhotic patients showed lower arachidonic acid levels than normal subjects; however, non-azotaemic cirrhotic patients and patients with FRF did not differ in relation to serum arachidonic acid. 3. Non-azotaemic cirrhotic patients had higher urinary PGE2, 6-keto-PGF1 alpha and TxB2 excretion than normal subjects and cirrhotic patients with FRF. Patients with FRF showed similar urinary PGE2 and TxB2 and lower urinary 6-keto-PGF1 alpha than normal subjects. In all cirrhotic patients no significant correlation was found between serum linoleic and arachidonic acid levels and urinary PGs. 4. In seven patients with FRF an acute intravenous infusion of linoleic acid induced a marked increase in serum levels of this fatty acid. However, no increase in serum arachidonic acid levels and urinary PG excretion and no improvement in renal function was observed. 5. This study suggests that an arachidonic acid deficiency is present in cirrhotic patients with ascites but that this abnormality is not a major determinant of renal function and PG production in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Methane production and colon cancer.

The cause of the high incidence of methane producers in patients with colorectal cancer is not clear. A total of 270 individuals were studied for methane production, using an end-expiratory breath sampling technique. They were divided into eight groups: 156 healthy controls (group 1); 47 patients with colorectal cancer (group 2); 36 patients (34 of them included in the previous group) after resection of the tumor (group 3); 7 (also included in group 2) with nonresectable tumor (group 4); 29 with nonmalignant diseases of the colon (group 5); 12 with extensive ulcerative colitis (group 6); 12 with ulcerative proctosigmoiditis (group 7); and 12 with colonic polyposis (group 8). Significantly more patients (91.4%) with colorectal cancer in group 2 produced methane than either healthy controls (42.9%) (p less than 0.001) or patients with benign diseases of the colon (41.3%) (p less than 0.001). In 36 patients (group 3) in whom the cancer was resected, the incidence of methane producers fell to 47.2%, similar to the control group, but significantly different from group 2 (p less than 0.001). The percentage of methane producers in patients operated on, but with unresectable cancer, remained very high (87.7%). A significantly higher proportion of patients with extensive ulcerative colitis (group 6) and colonic polyposis (group 7) produced methane than patients with ulcerative proctosigmoiditis (group 7), benign diseases of the colon (group 5), and healthy controls (p less than 0.05). The results suggest that the presence of cancer in the large bowel directly influences methane production. In addition, in the group of diseases with a high risk of malignancy, the prevalence of methane-producing individuals was significantly higher than in the healthy population and in patients with benign diseases of the colon.

Fat digestion and exocrine pancreatic function in primary biliary cirrhosis.

Intestinal bile salt deficiency marginally impairs fat absorption in cholestatic patients. The finding of massive steatorrhea in some patients with primary biliary cirrhosis led us to systematically study and compare fat digestion in control subjects (n = 4) and patients with biliary cirrhosis with (n = 11) and without (n = 3) steatorrhea. The jejunum was anatomically and functionally intact in all subjects, as demonstrated by normal gastrointestinal radiology and xylose absorption, respectively. The intestinal contents were recovered during digestion of a fat meal. Lipolysis, pH, and trypsin activity were measured in whole intestinal contents, whereas bile salts, total lipid, and fatty acid were determined in both total and aqueous phases. The results obtained in controls and patients without steatorrhea were similar. Percentage of lipolysis and intraluminal pH were normal in controls and in both patient groups. The intestinal contents of the patients with steatorrhea had a significantly lesser capacity to solubilize both total lipid and fatty acid in relation to abnormally low aqueous bile salt concentrations. No bile salt deconjugation and only minimal bile salt precipitation were found, thus low aqueous bile salts were strictly related to bile secretory failure. Steatorrhea was always present when aqueous bile salt levels were below 3.0 mM. Intestinal trypsin activity was subnormal in patients with steatorrhea; decreased trypsin activity was related (r = 0.82, p less than 0.001) to reduced intestinal bile salt levels. One patient was found to have severe exocrine pancreatic failure. Administration of medium chain triglycerides was uniformly effective in improving nutrition in patients with steatorrhea, but the course of the disease was unaffected. These results indicate that overt pancreatic failure is uncommon in primary biliary cirrhosis, and that fat maldigestion and steatorrhea, regardless of what degree, are due mainly to low intestinal bile salt levels secondary to bile secretory failure. Finally, subnormal pancreatic function in this disease appears to be related to the bile secretory failure, suggesting either that the lack of bile or bile salts in the intestine depresses pancreatic exocrine function or that both biliary and pancreatic secretions decrease in parallel as part of a widespread secretory failure syndrome.