C. Heusghem

Effect of the haptoglobin phenotype on the size of a myocardial infarct.

We investigated the relation between haptoglobin (Hp) phenotypes and serum levels of various biochemical markers after myocardial infarction in 496 patients. In 122 subjects selected on the basis of short delays until hospitalization, patients with Hp 2-2 had higher cumulated creatine kinase activity than patients with Hp 1-1, or Hp 2-1 (P less than 0.05), as well as higher myoglobin concentrations (P less than 0.02) 12 to 28 hours after admission. Comparison of serum enzyme activities in the remaining 374 patients confirmed that Hp 2-2 patients had significantly higher total creatine kinase, creatine kinase isoenzyme MB fraction, aspartate aminotransferase, and lactate dehydrogenase peak levels. Complications of left ventricular failure were more frequent in these patients (P = 0.05). Our results suggest that Hp 2-2 patients have more severe myocardial infarctions than Hp 1-1 and Hp 2-1 patients, However, no difference in the distribution of haptoglobin phenotype was found between patients who had a myocardial infarction and healthy subjects, indicating that Hp 2-2 does not predispose to the occurrence of infarction.

Semi-quantitative estimation of serum myoglobin by a rapid latex agglutination method: an emergency screening test for acute myocardial infarction

The present study reports the evaluation of a new latex agglutination test for serum myoglobin (SMb). The time of agglutination of the latex particles coated with antibodies to myoglobin was measured in 172 serum specimens with known concentration of myoglobin quantitated by a radioimmunoassay (RIA), collected from myocardial infarction (MI) patients, subjects suffering from various diseases, and normal controls. Myoglobin levels in the samples were found to decrease exponentially with time of agglutination. Agglutination occurring within 1 min (result coded as + + + +) corresponded to 761 +/- 366 micrograms/l of myoglobin; between 1 and 2 min (+ + +), to 285 +/- 101 micrograms/l; between 2 and 3 min (+ +), to 85 +/- 47 micrograms/l; between 3 and 4 min (+), to 51 +/- 38 micrograms/l; and after more than 4 min (-), to 31 +/- 16 micrograms/l. Blood samples were serially drawn from 24 MI patients with short hospitalization delays; the rapid agglutination which was obtained in the specimens taken upon admission (20 results coded as + + + + and four as + + +) actually corresponded to markedly increased SMb levels. In contrast, serum creatine kinase (CK) activities were still less than 150 U/l in four patients (16.6%); CK-MB was less than 5 U/l in five cases (20.8%). Positive agglutinations for SMb were also obtained 4 and 8 h following admission in all subjects, confirming that the latex test is an early and very sensitive indicator for MI.(ABSTRACT TRUNCATED AT 250 WORDS)

The protection of creatine kinase MM sub-bands by EDTA during storage

We examined the effect of a 5 mmol/l concentration of EDTA on the stabilization of the five serum creatine kinase MM isoenzymes, resolved by thin-layer isoelectric focusing. In patient sera, total CK and CK-MB activities were stable during storage of the samples for two months at 4 degrees C even in the absence of EDTA. However, EDTA stabilized the labile MM and MM1 sub-bands, which are the first to appear in the blood after the release from the damaged tissue and its addition to blood samples intended for determining the MM sub-band pattern is recommended. The stabilizing effect of EDTA was emphasized at higher temperatures. EDTA protected the CK-MM pattern in myocardium extracts made in normal serum and incubated at 37 degrees C during 40 h, but was unnecessary when myocardium was homogenized in heat-inactivated serum. It is thought that EDTA could act by inhibiting a heat-labile component of human serum.

Predictive value of serum enzyme determinations in acute myocardial infarction

Abstract The prognostic significance of serum enzyme measurements in acute myocardial infarction was studied in 146 patients hospitalized shortly after the attack. Creatine kinase (CK), CK-MB, aspartate aminotransferase (ASAT) and lactate dehydrogenase (LDH) were serially determined every four hours during the first three days following admission. Peak enzyme levels correlated well with the cumulated CK release ( r = 0.95, 0.74, 0.70 for CK, ASAT and LDH respectively). Among all enzyme measurements, LDH levels determined when CK reached its peak value provided the best discrimination between acute phase survivors (15 days) and non-survivors. LDH was also the best measurement for identifying patients with ventricular impairment. LDH and ASAT peak levels were more powerful predictors of the patients risk than CK peak levels. CK levels determined later in the course of myocardial infarction were more discriminant, indicating prolonged CK elevation in non-survivors. There was no significant difference in CK-MB levels, nor in cumulated CK-MB amounts for survivors and non-survivors. It is concluded that serum LDH activity is a better predictor of the short term evolution of myocardial infarction than CK levels or infarct size estimations from serial CK determinations.

The value of serum CK-MB and myoglobin measurements for assessing perioperative myocardial infarction after cardiac surgery

In 41 patients who underwent coronary bypass surgery, creatine kinase (CK)-MB mass concentration was repeatedly measured in serum during and after the intervention using a new two-site immunoenzymetric assay (IEMA). Serum CK-MB activity was determined with the use of four different techniques: immunoinhibition, immunoinhibition-immunoprecipitation, column chromatography and electrophoresis. Myoglobin (Mb) was also measured in each specimen by radioimmunoassay. In the 33 patients who followed a completely uneventful postoperative course, the cumulated CK-MB release was, on the average, 12.2-fold less than after acute myocardial infarction. The CK-MB peak concentrations using the IEMA were 33 +/- 3 micrograms/l (X +/- SEM) and occurred 6.4 +/- 0.5 h after the intervention was started; CK-MB levels had decreased to 2.9 +/- 0.4 micrograms/l at the end of the first postoperative day. The evolution of the CK-MB concentration was parallel to that of the enzyme activity. The serum Mb maximum concentrations (518 +/- 39 micrograms/l) were reached after 3.3 +/- 0.1 h. The other eight patients developed perioperative myocardial infarction (PMI); in this group, the cumulated CK-MB release was higher, and the serum CK-MB postoperative curves were of three different types. The patients with delayed CK-MB peaks (type I pattern) or sustained elevations (type III) of this isoenzyme also showed increased serum Mb levels at the end of the first postoperative day. The PMI patients with early (10 h) CK-MB elevations (type II) did not demonstrate abnormal serum Mb levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Variations enzymatiques dans le plasma du rat aprés injection d'une dose radioprotectrice de cysteamine.

Abstract Various intracellular enzymes (TGO, LDH, MDH, G1DH, β/glycuronidase) have been titrated in the plasma of adult rats after an i.p. injection of 100 mg kg of cysteamine (base). A large increase in the level of these enzymes is observed after 25 min; the maximum is reached in 2 hr; normal levels are observed after 6 hr. Regular variations in the LDH isoenzymes have not been seen, but in a number of rats a doubling of the fifth fraction has been observed in late (4 or 6 hr) plasma samples. These facts show that a large radioprotective dose of cysteamine induced an intense and rapid, but easily reversible, cellular “shock”; they are compatible with the observations of various authors using electron microscopy.

Critical evaluation of serum uric acid levels in acute myocardial infarction.

Serial measurements of serum uric acid were performed on patients suffering from acute myocardial infarction. Nearly 80 percent of the cases demonstrated a fall in uric acid concentrations during the first two days of hospitalization and a subsequent return to initial levels within six to eight days. There was a relationship between the decrease in uric acid levels and the serum lactate dehydrogenase activity. No evidence could be found that male patients were hyperuricemic as compared to control subjects. However, female patients between 40 and 60 years of age demonstrated significantly higher uric acid levels than healthy women of corresponding ages, even after adjustment for diuretic use.

Influence du β-mercaptoethanol sur certains enzymes plasmatiques du rat

Abstract Intraperitoneal injection of 160 mg/kg of β-mercaptoethanol in rats does not change the plasma levels of various enzymes (TGO, LDH, MDH, G1DH, β-glucuronidase) which are much increased by β-mercaptoethylamine. This amine protects against ionizing radiation; mereaptoethanol does not.

Improved Detection of Perioperative Myocardial Infarction After Cardiac Surgery Using CK-MB Mass Measurements

After coronary bypass surgery (CBS), late survival is reduced in patients who develop perioperative myocardial infarction (PMI) as compared with the uncomplicated cases [4, 8]. Therefore the improvement of individual therapy in these patients depends on our capacity reliably to select high-risk cases during the early postoperative period.

Serum creatine kinase isoenzyme MB concentration after endomyocardial biopsy

Serum total creatine kinase (CK), CK-MB and myoglobin (Mb) were serially determined in 17 patients who underwent endomyocardial biopsy. Mean total CK levels increased from 36 +/- 27 U/l 30 min before biopsy to a maximum of 112 +/- 77 U/l 8 h following the procedure (p less than 0.05). Similarly, Mb concentrations rose from 57 +/- 55 micrograms/l to 119 +/- 57 micrograms/l 30 min after biopsy (p less than 0.05). Normalization of total CK and Mb levels occurred within 16 and 8 h, respectively. A new immunoenzymetric assay (IEMA) was used to measure the mass concentration of the CK-MB molecule. The initial CK-MB levels were 0.2 +/- 0.4 microgram/l; a small but significant elevation was recorded as early as 2 h after biopsy (1.6 +/- 1.5 micrograms/l, p less than 0.05). CK-MB returned to initial concentration 16 h after the beginning of the procedure. Comparison with the maximum CK-MB levels recorded in 16 myocardial infarction patients (258 +/- 172 micrograms/l, range 90-680 micrograms/l) indicated that the modest increase of CK-MB level detected after biopsy probably reflects a limited endomyocardium lesion at the sampling site, excluding any significant myocardial damage. Total CK and Mb, which showed more pronounced elevations than CK-MB, are likely to originate from other sources than the myocardium.