Reference intervals for eight enzymes in blood of adult females and males measured in accordance with the International Federation of Clinical Chemistry reference system at 37 degrees C: part of the Nordic Reference Interval Project.

As part of the Nordic Reference Interval Project we present reference intervals for alanine transaminase (ALT), aspartate transaminase (AST), creatine kinase (CK), lactate dehydrogenase (LD), alkaline phosphatase (ALP), gamma-glutamyltransferase (GT), amylase (AMY) and pancreatic type of AMY in blood of adult males and females. A total of 3036 reference persons, all of whom considered themselves to be in good health, were recruited by 102 Nordic clinical biochemical laboratories. Exclusions were undertaken on the basis of predefined biochemical and clinical criteria. Enzyme activities in serum and plasma were measured in the different laboratories using various commercially available routine measurement systems at 37 degrees C. Only results obtained with the International Federation of Clinical Chemistry (IFCC) compatible measuring systems were selected for estimation of the enzyme reference intervals. The final number of results on each enzyme varied from 459 (LD) to 2300 (ALT). The 2.5 and 97.5 percentile reference limits were calculated by a non-parametric method in accordance with the IFCC recommendations, using the Refval 4.0 data program. Statistical partitioning testing was undertaken to decide whether the reference intervals ought to be partitioned according to gender and/or age. For most of the enzymes, but not for all, the upper reference limits were found to be higher than those that have been in general use until now.

[New cardiac markers--clinical benefits in early diagnosis of acute heart disease]. / Nye hjertemarkører--klinisk nytte ved tidlig diagnose av akutt hjertesykdom.

BACKGROUND: New cardiac markers that may be analysed around the clock in emergency can now be performed in our hospitals with commercially available reagents and equipment. Upon the introduction of a new clinical biochemical regime based on these new markers for the diagnosis of acute coronary syndromes, we evaluated the clinical benefit achieved by the new set-up, especially with respect to early diagnosis. MATERIAL AND METHODS: cTroponinT, CK-MBmass, myoglobin and total-CKactivity were analysed in blood sample taken on admission, after 2-3 hours, and further once or twice over the next 24 hours in 300 patients admitted on suspicion of acute coronary syndromes (ACS). The study was based on results of the cardiac markers and information given on questionnaires by the physicians in charge. RESULTS: With the decision limits applied, CK-MB and myoglobin showed slightly higher sensitivity than cTroponinT for detecting acute myocardial infarction within the first 2-3 hours. cTroponinT showed the highest sensitivity for detecting heart muscle damage in patients with unstable angina. cTroponinT was the most cardiospecific marker. If the patient was considered not having ACS after the first few hours, only 3% ended with a diagnose of unstable angina and none with acute myocardial infarction. Of those considered certain ACS cases after the first few hours, 92% ended up with the diagnosis acute myocardial infarction or unstable angina. Treatment and/or supervision were changed in 68 of 220 patients based on the results of the two first blood samples, 85% of them to a lower level of supervision. INTERPRETATION: cTroponinT and CK-MB are useful markers for early detection of acute myocardial injuries. A prerequisite is that they are determined in two samples with an interval of at least two hours. In this case, myoglobin did not give additional information. Based on the results from two early blood samples, about one quarter of the patients could immediately be transferred to a less expensive level of care.

[Diagnoses and increased levels of troponin T among discharged patients]. / Utskrivningsdiagnoser ved forhøyede troponin T-verdier.

BACKGROUND: New criteria for diagnosing acute myocardial infarction, in which the cardiac troponin T or I plays a central role, have recently been proposed. We wanted to estimate what an application of these criteria would have meant for the diagnoses given patients discharged from our hospital in 2000. MATERIAL AND METHODS: From the hospital data bases, 3,461 in-hospital patients were identified in whom troponin T levels in blood had been determined. Maximal troponin T levels and diagnoses on discharge were recorded. Only one diagnosis was used for each patient. The diagnoses were selected in a priority order favouring those diseases that are known most often to cause increased troponin T levels, starting with the codes for acute myocardial infarction. RESULTS: By applying the new criteria, the number of patients with myocardial infarction was estimated to increase 17%, 33% and 61% depending on the decision level for troponin T used, 0.20, 0.10 or 0.03 microgram/l, respectively. Congestive heart failure and atrial fibrillation were the most frequent cardiac diagnoses in patients with increased troponin T level without evidence of acute coronary syndromes. Other, non-cardiac diagnoses included renal diseases, sepsis, and acute lung diseases. INTERPRETATION: Application of the new diagnostic criteria will markedly increase the recorded incidence of acute myocardial infarction. The number of positive troponin T values in patients without acute coronary syndromes will increase progressively by lowering the diagnostic decision level of troponin T.

[Troponins and other biochemical cardiac markers--time for a change]. / Troponiner og andre nye biokjemiske hjertemarkører--tid for et skifte.

BACKGROUND: During the last ten years new, more sensitive and specific cardiac markers in blood for detection of acute myocardial injuries have been characterised and clinically evaluated. Of practical importance is also the fact that rapid and robust methods and equipments suitable for emergency service have been developed. MATERIAL AND METHODS: Based on literature study and on own experiences we give a survey of the most promising cardiac markers with emphasis on the troponin T and troponin I. RESULTS: Methodological and pathobiochemical aspects are discussed. The diagnostic characteristics and advantages of the new markers are in focus, especially with respect to early detection of acute myocardial injuries. Finally, we discuss their potential use for stratification of patients with acute coronary syndromes with respect to optimal treatment, resource-saving monitoring, and more precise prognostication. INTERPRETATION: It is recommended that one of the troponins, either I or T, should be included in the diagnostic regime for detecting acute coronary syndromes in Norwegian hospitals. CKMB, determined as mass and not as activity, ought to be retained, at least until more clinical experience with the troponins have been gained by the hospital. Myoglobin may only be of interest if early exclusion of myocardial injuries has practical consequences. In this connection the transaminases and LDH are no longer of any interest.

Serial measurements of cardiac markers to rule in or out acute myocardial damage less than 3 h after admission in acute chest pain patients without ECG-signs of acute myocardial infarction.

Acute chest pain patients without ECG-signs of acute myocardial infarction (AMI) on admission need to be earlier and better diagnosed to reduce use of expensive intensive care beds and to treat more patients with acute recirculation therapy. We investigated whether total CK-activity, CK-MB mass, CK-MB2, myoglobin, cardiac troponin I (cTnI) and T (cTnT) measured in venous blood on admission and after 1 and 2 h could be used to identify or exclude acute myocardial damage (AMD) in 22 acute chest pain patients without ECG-signs of AMI admitted to hospital within 6 h after onset of pain. Increases in CK-MB mass, CK-MB2, myoglobin and cTnI identified AMD in three patients classified retrospectively as AMI. Likewise, CK-MB mass, CK-MB2, cTnI and cTnT increased with time in three of seven patients classified as having unstable angina pectoris. CK-MB2 and cTnI increased with time in two patients with tachycardia belonging to the other heart disease group. The remaining seven patients of the non-heart disease group showed no change in any of the cardiac markers. Thus, early serial measurements of selected cardiac markers appear useful in identifying or excluding AMD 3 h after admission in these acute chest pain patients.

Severe organophosphate (demeton-S-methyl) poisoning in a two-year-old child.

A previously healthy 2-y-old boy was admitted to the hospital 30 min after the ingestion of 10 ml of demeton-S-methyl (META-SYSTOX). Treatment consisted of gastric decontamination, atropine, reactivator (obidoxime) and supportive therapy. Atropine was given to control the muscarinic features. Assisted ventilation was required for 6 h; however, this treatment was able to be discontinued following the second injection of obidoxime 11.5 h after the ingestion. Excess salivation and slight bradycardia were easily controlled with small doses of atropine for 5 d following admission to Ullevaal Hospital. Further course was uneventful, and the patient was discharged on the 8th d without any sequelae. Plasma cholinesterase levels were initially low (<400 U/l), but returned to reference values upon discharge. In this case, adequate supportive therapy and the rapid administration of both atropine and obidoxime were clearly associated with a favorable outcomes

Myocardial damage during percutaneous transluminal coronary angioplasty as evidenced by troponin T measurements.

AIM: The present study was undertaken to assess the effect of balloon inflation during percutaneous transluminal coronary angioplasty on markers of myocardial damage. METHODS AND RESULTS: Seventy-five patients undergoing elective percutaneous transluminal coronary angioplasty were evaluated with serum creatine kinase MB and cardiospecific troponin T before and 1 and 4 days after the procedure. On day 1, 28% of the patients had increased cardiospecific troponin T values and 18% had increased creatine kinase MB values. On day 4, 24% had increased cardiospecific troponin T values, whereas all creatine kinase MB values were normal. A high degree of correlation between creatine kinase MB and cardiospecific troponin T on day 1, as well as between both markers on day 1 and cardiospecific troponin T on day 4 were found. The increased levels of cardiospecific troponin T on day 4 was significantly correlated with the total balloon inflation time (P < 0.001). CONCLUSION: We conclude that irreversible myocardial damage, as evidenced by increased cardiospecific troponin T values on day 4, occurs in an appreciable number of patients during percutaneous transluminal coronary angioplasty, and that this damage is strongly correlated with the total balloon inflation time.

Markers of myocardial injury in blood following PTCA: a comparison of CKMB, cardiospecific troponin T and troponin I.

In 74 patients undergoing elective PTCA, CKMB, cTnT, cTnI-Access (cTnI-Acc) and cTnI-Abbott (cTnI-Abb) were measured in serum before and days 1 and 4 after the procedure. Two of the patients had pronounced biochemical evidence of AMI. In addition, a minor to moderate increase in CKMB, cTnT, cTnI-Acc and cTnI-Abb were found on day 1 in 13, 22, 18 and 25 patients, respectively. Excluding the two with AMI, cTnT was also increased on day 4 in 16 patients and cTnI-Abb in 15 patients, whereas CKMB and cTnI-Acc levels were essentially normal in all. Thus, an unexpected discrepancy between the two methods for cTnI was revealed on day 4. In these 16 patients, there was no statistically significant relationship between the level of cTnT on day 4 and the levels of CKMB or cTnI-Acc on day 1. This is in contrast to a significant correlation to cTnT and cTnI-Abb on day 1. Based on these results, it is speculated that the marker levels on day 1 are due to reversible as well as irreversible damage, whereas cTnT and cTnI-Abb on day 4 more selectively reflect the degree of myocardial necrosis. cTnT and TnI-Abb on day 4 are therefore proposed as valuable markers for further study of the clinical implications of myocardial damage following PTCA and related interventions.

Effects of clodronate on cortical and trabecular bone in ovariectomized rats on a low calcium diet.

The aim of this study was to evaluate the contribution of a low calcium diet to the cortical and trabecular osteoporosis seen in ovariectomized rats after 7 weeks on a low calcium diet and to investigate the effects of the bisphosphonate clodronate on this development of osteoporosis. Thirty-six mature, female Wistar rats were randomized into four groups: Ovx-B (bisphosphonate) and Ovx-C (control) were ovariectomized, and Sham-Ca (low calcium) and Sham+Ca (normal calcium) were sham operated. The first three groups were fed a low calcium diet (0.01%) and Sham+Ca normal rat chow (Ca 1.1%). The Ovx-B received 10 mg/kg s.c. clodronate daily for nine weeks, and Ovx-C, Sham-Ca, and Sham+Ca received the same volumes of saline. Bone mineral turnover measured as 85Sr-uptake was increased in all low calcium groups compared to Sham+Ca. The Sham+Ca femora had higher dry weight and ash weight than the other groups, and Ovx-C had higher dry weight compared with Ovx-B and Sham-Ca. Calcium content was lower in both Ovx groups compared to both Sham groups. Magnesium was lower in all groups compared to Sham+Ca and higher in Ovx-B compared with Ovx-C. In the femoral shaft, Sham+Ca had significantly higher ultimate bending moment, energy absorption, and deflection compared to the other three groups. Ultimate bending moment was higher in Sham-Ca than in Ovx-C. Stiffness was increased in both Sham+Ca and Ovx-B compared to Ovx-C. The maximum stress in the femoral midshaft was higher in Sham+Ca than in the other groups, and higher in Ovx-B than in Ovx-C. Histomorphometry showed increased medullary area in all low calcium groups compared to Sham+Ca and larger cortical area in Sham+Ca and Ovx-B compared to Ovx-C. Compared to Sham+Ca the trabecular bone volume was decreased to 30% in Sham-Ca and to 9% in Ovx-C, but was unchanged in Ovx-B. The low calcium diet generally increased bone mineral turnover and reduced the tibial bone volume. Femoral changes led to a reduction of cortical fracture strength and maximal stress. Ovariectomy in addition to a low calcium diet reduced femoral strength even more. Daily injections of clodronate to ovariectomized rats on a low calcium diet increased femoral shaft stiffness and maximum stress, and clodronate preserved both trabecular and cortical tibial bone volume completely.

The development of femoral osteopenia in ovariectomized rats is not reduced by high intensity treadmill training: a mechanical and densitometric study.

The effect of treadmill running on the development of osteopenia was investigated in adult ovariectomized (OVX) rats compared with sedentary OVX and sedentary sham-operated rats. The rats were 3 months old with a mean weight of 214 g. OVX rats were fed a low calcium diet (0.01%), and the sham rats received the normal diet (1.1% calcium). The training consisted of treadmill running at a speed of 27 m/minute for 1 hour 5 out of 7 days during a period of 8 1/2 weeks. The weight gain was higher in the sedentary OVX (108 g) than in the training OVX (62 g) and sham-operated rats (61 g) (P < 0.001). Comparing the two OVX groups, training had no significant effects on the development of femoral osteopenia as assessed by mechanical testing of the femoral shaft and neck, and by bone mass measurements by dual energy X-ray absorptiometry (DXA) or by ashing. Comparing all three groups bone mineral content (BMC) and bone mineral density (BMD) were reduced by more than 40% in both the OVX groups compared with the sham-operated rats (P < 0.001). Ash weight and calcium content were reduced by approximately 40% in both OVX groups. Femoral volume and length were 10% higher in the sedentary OVX animals compared with the trained (P < 0.05), indicating that the training had had a negative effect on the growth changes induced by ovariectomy. The fracture strength of the femoral shaft was reduced by 26% and 22% in the trained and sedentary OVX rats, respectively compared with the sham-operated group (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum cardio-specific troponin T after open heart surgery in patients with and without perioperative myocardial infarction.

One hundred and sixteen consecutive patients undergoing open heart surgery were studied to evaluate the diagnostic use of cardiac specific troponin T in serum (S-TnT) measured preoperatively, at day 1 and day 4 postoperatively. The results were related to perioperative myocardial infarction (POMI), diagnostically based on ECG-changes, as well as to other perioperative variables. Cardiac surgery resulted in increased levels of S-TnT day 1 in all patients, and the level of this increase was dependent on the type of surgical procedure performed and the duration of cardiac perioperative ischaemia. Similar results were observed for serum creatine kinase isoenzyme (mass determination) (S-CKMB), but differences were generally less well correlated with other perioperative variables. At day 1, patients with POMI had higher levels of S-TnT as well as S-CKMB when compared to patients without POMI. At day 4, most patients still had elevated levels of S-TnT, but the difference in S-TnT levels between patients with POMI and patients without POMI was more pronounced. In contrast, the levels of S-CKMB were essentially normalized in both groups. Measurements of S-TnT at day 4 appears to be of significant value in diagnosing POMI. However, most of the patients without POMI had increased levels of S-TnT at day 4, suggesting that some irreversible operatively induced myocardial damage had occurred. Thus, even at a late postoperative stage the perioperative duration of ischaemia and type and extent of the surgical procedure should be taken into consideration.

[Metabolic acidosis--a diagnostic challenge]. / Metabolsk acidose--en diagnostisk utfordring.

Metabolic acidosis can be caused by a variety of pathological conditions, but intoxication with ethylene glycol or methanol should be suspected in cases of a combined increase of osmolal and anion gaps. The determination of the gaps is based on readily available laboratory tests, and the results is known soon after the blood sample is taken. This procedure is of particular interest for hospitals where specific analyses for methanol and ethylene glycol are not available, since calculation of the gap can give an early indication of what treatment to use. Therefore, the gaps should be calculated as a routine in patients with metabolic acidosis of unknown origin. The authors describe the principles for calculating and using the gaps, and report three cases which illustrate their usefulness in practice.

Effects of the prostaglandin E2 analogue enprostil on the carbon tetrachloride-induced necrosis of liver cells in mice.

Female mice, eight weeks old, were injected with carbon tetrachloride (CCl4) (10 mg subcutaneously). Groups of mice (n = 10-30) were then injected with enprostil (E) 2, 20 or 50 micrograms/kg body weight (bw) intraperitoneally 15 min and two h after, or E 100 micrograms/kg bw two h after the CCl4 injection. The mice were killed after 24, 48 or 72 h. Plasma activity concentrations of alanine aminotransferase (ALAT) were determined in blood specimens from the iliac veins. The extent of liver cell necrosis in histological sections was recorded on a 100 mm Visual Analogue Scale (VAS) and measured using the electronic Mini Mop method. In the group given the highest single dose of E (100 micrograms/kg) a significant lowering of the CCl4-induced liver cell necrosis was found after 24 h. No significant differences were found after 48 and 72 h. In the other groups injected with lower doses of E after CCl4, no significant differences were found compared to groups injected with CCl4 alone.

Co-variation of alanine aminotransferase levels with relative weight in blood donors.

The association between alanine aminotransferase (ALAT) and body mass, sex and age was examined in 6036 consecutively tested blood donors. ALAT, age and body mass were higher in male donors than in female donros. The non-normal ALAT distribution curve normalized after 1n transformation, which made statistical analysis of the data more feasible. Multiple regression analysis demonstrated that ALAT was influenced by sex and relative weight, in that order, and very poorly by age. It is concluded that obesity is a major cause of raised ALAT in this predominantly healthy donor population.

Prevalence of anti-HCV in Norwegian blood donors with anti-HBc or increased ALT levels.

Testing for hepatitis B core antibodies (anti-HBc) was performed in 12,104 consecutive blood donors, 139 (1.15%) of whom were found to be positive. The first 6036 donors were also screened for ALT; 91 (1.51%) had repeatedly elevated values. ALT screening was of no help in detecting anti-HBc-positive donors. Those with anti-HBc or repeatedly raised ALT levels were further tested for hepatitis C virus antibodies (anti-HCV), and 3 (2.16%) and 1 (1.10%) anti-HCV-positive donors were detected, respectively. This prevalence of anti-HCV (0.5%) is not significantly different from that found in 1000 unselected donors at our blood bank. Testing for ALT and anti-HBc as surrogate markers for hepatitis C is therefore not recommended in Norwegian blood donors and should be replaced by anti-HCV screening.

[Organophosphate poisoning]. / Organofosfatforgiftning.

Three cases of poisoning by organophosphate dimethoate are described and the importance of correct diagnosis and adequate treatment emphasized. Therapy consists of large doses of atropine, to counteract the muscarinic and other effects on the central nervous system, followed by a reactivator (e.g. toxogonin) to reverse muscle weakness (nicotinic effects).

Ethanol elimination-rates determined by breath analysis as a marker of recent excessive ethanol consumption.

The rate of ethanol elimination was studied in two groups of men by means of an Alcotest 7010 breath analyser. The experimental group consisted of 15 skid-row alcoholics undergoing detoxification. Their median daily ethanol consumption was 211 (range 26-476) g pure ethanol during the last year. The control group was made up of 12 age-matched healthy social drinkers consuming 9 (range 4-23) g day-1 pure ethanol during the last year. The median ethanol elimination-rate in the elimination phase was 0.25 (range 0.13-0.31) g 1-1 h-1 during the detoxification period in the experimental group. This value was approximately 70% higher than in the control group (0.14(0.12-0.17) g 1-1 h-1). Some correlation was found between reported ethanol intake, and the calculated ethanol elimination-rate, as well as gamma glutamyl transferase (GGT), alanine amino transferase (ALAT), aspartate amino transferase (ASAT), glutamate dehydrogenase (GLDH), mean corpuscular volume (MCV) and HDL-cholesterol. Of these measures, ethanol elimination-rate showed highest sensitivity and efficiency for detection of ethanol consumption above the limit of 50 g per day.

[Enzyme status in myocardial infarction]. / Enzymstatus ved hjerteinfarkt.

Less than 50% of the patients sent to hospital with suspected acute myocardial infarction do in fact suffer from myocardial necrosis. Changes in serum-enzyme levels are important findings when diagnosing acute myocardial infarction. Blood sampling frequency and which enzymes to measure are crucial for obtaining maximum information. We have studied different enzyme-regimes for the purpose of diagnosing acute myocardial infarction quickly and reliably. It is also necessary to consider consumption of resources. In our study, myoglobin was the best early parameter. The efficiency was only 66%, however, and the specificity was low. We therefore conclude that reliable early diagnosis of acute myocardial infarction based on serum-analyses is not yet possible. The best results were achieved using a strategy consisting of five blood samples (every eight hours during the first 24 hours and a final sample about 48 hours after hospitalisation). Changes in the activities of CK and LD in this period gave valuable information for the diagnosis, the size (measured as an increase in enzyme activity) of an eventual acute myocardial infarction, and the dynamic development of the disease. The sensitivity of the Nordic recommended regime, i.e. two samplings 10-20 hours after start of symptoms, was low (75%). The problem was estimating when the necrotic process had started.

Beta-glucuronidase activity related to bacterial growth in common bile duct bile in gallstone patients.

Beta-glucuronidase activity in the bile may be of importance in the etiology of pigment gallstones. This enzyme is of hepatic or bacterial origin. We have described a method to measure the activity of bacterial beta-glucuronidase in human bile, using 4-nitrophenyl-beta-D-glucopyranosiduronic acid as substrate. The method was used to measure the beta-glucuronidase activity in the bile from 51 patients with gallstone disease. This activity was related to the presence of beta-glucuronidase-producing bacteria in the bile. Escherichia coli, Bacteroides species, and Clostridium perfringens were the only species found to produce beta-glucuronidase. Patients with beta-glucuronidase-producing bacteria had on an average significantly higher enzyme activity in the bile than patients without such bacteria (p less than 0.01). The limitations of using artificial substrates in this type of studies are discussed.