Changes in creatine kinase activity in the course of acute myocardial infarction

Peak activity of creatine kinase (CK; EC 2.7.3.2) and its decline were determined in 380 patients with acute myocardial infarction (AMI) whose CK values had peaked after admission to the hospital. During hospitalization, 26 patients either died (14 patients) or experienced nonfatal re-infarction (12 patients). In 22 of these 26 patients CK activity decreased by less than 50% within 48 h after the peak value was measured. In all patients who did not die or develop re-infarction, CK activity decreased by greater than 50% during the 48 h after the peak. Evidently the rate of decline of CK (i.e., whether more than or less than 50%) from its peak value during the 48 h after AMI may be helpful in assessing which patients are at high risk for developing re-infarction or dying.

Atrial fibrillation. Cause and time of onset

To characterize groups of patients presenting at the emergency room with atrial fibrillation (AF) according to the various causes of AF and the time of its onset, 704 medical files from the Beilinson Medical Center (Petah Tikva, Israel), during an eight-year period, were reviewed. Two thirds of all patients converted to sinus rhythm (SR) within a seven-day in-hospital treatment. The most frequent causes associated with AF were atherosclerotic cardiovascular disease, 55%; rheumatic heart disease, 22.8%; chronic obstructive pulmonary disease, 2.8%; Wolf-Parkinson-White syndrome, 2.6%; and thyrotoxicosis, 2.6%. There was a relatively large group of idiopathic AF (4.5%). Best convertors to SR were patients with idiopathic AF (93.9%), then patients with Wolf-Parkinson-White syndrome (88.8%), followed by atherosclerotic cardiovascular disease (71.6%), and thyrotoxicosis (63.2%). Patients with rheumatic heart disease and chronic obstructive pulmonary disease had the lowest percentage of successful conversion to SR--46% and 55%, respectively. We conclude that there are differences regarding gender, age, and possible conversion of AF to SR according to the different causes of AF.

Patterns of lactate dehydrogenase isoenzymes 1 and 2 in serum of patients performing an exercise test

Values for total lactate dehydrogenase (LD, EC 1.1.1.27) activity and LD isoenzymes were determined in serum from 56 patients and 40 healthy subjects before and 24, 48, and 72 h after they performed an exercise test. The mean (for all four times) total LD activity concentration and proportion of LD-2 were within the normal range for all 96 subjects. Mean LD-1 values for serum, although within the normal range in all subjects, were significantly higher in patients with positive exercise test results than in subjects with negative results: 75 (SD 12) U/L in 35 patients with ST depression greater than 2 mm; 63 (SD 14) U/L in 16 patients with ST depression of 1-2 mm; 43 (SD 11) U/L in subjects with negative test results, by 48 h after the test. The LD 1:2 ratio was also markedly higher in the group of patients with positive test exercise results, especially in those with ST depression greater than 2 mm (1.02, SD 0.06), compared with those subjects with negative results (0.60, SD 0.04). A similar trend was also found 24 and 72 h after the exercise test. We conclude that exercise-myocardial ischemia may lead to an increased LD 1:2 ratio in serum, and demonstrate a correlation between the degree of ischemia and the LD 1:2 ratio. Determination of the LD 1:2 ratio, even in the presence of normal total LD activity, may assist in the clinical evaluation of patients performing an exercise test.

Patterns of lactate dehydrogenase isoenzymes 1 and 2 in serum of patients performing an exercise test

Values for total lactate dehydrogenase (LD, EC 1.1.1.27) activity and LD isoenzymes were determined in serum from 56 patients and 40 healthy subjects before and 24, 48, and 72 h after they performed an exercise test. The mean (for all four times) total LD activity concentration and proportion of LD-2 were within the normal range for all 96 subjects. Mean LD-1 values for serum, although within the normal range in all subjects, were significantly higher in patients with positive exercise test results than in subjects with negative results: 75 (SD 12) U/L in 35 patients with ST depression greater than 2 mm; 63 (SD 14) U/L in 16 patients with ST depression of 1-2 mm; 43 (SD 11) U/L in subjects with negative test results, by 48 h after the test. The LD 1:2 ratio was also markedly higher in the group of patients with positive test exercise results, especially in those with ST depression greater than 2 mm (1.02, SD 0.06), compared with those subjects with negative results (0.60, SD 0.04). A similar trend was also found 24 and 72 h after the exercise test. We conclude that exercise-myocardial ischemia may lead to an increased LD 1:2 ratio in serum, and demonstrate a correlation between the degree of ischemia and the LD 1:2 ratio. Determination of the LD 1:2 ratio, even in the presence of normal total LD activity, may assist in the clinical evaluation of patients performing an exercise test.

Myocardial protection by 2-mercaptopropionylglycine during global ischemia in dogs

The hypothesis was tested, if the addition of 2-mercaptopropionylglycine (MPG, Thiola) to a crystalloid cardioplegic solution provides superior myocardial protection as assessed by biochemical and morphological parameters. Five mongrel dogs underwent a 60-min hypothermic cardioplegic arrest (untreated group). In six dogs, MPG (1.5 mmol/l) was added to the crystalloid cardioplegic solution (treated group). Thereafter a reperfusion phase of 60 min was established. At the end of the reperfusion phase samples for mitochondrial respiration parameters and for mitochondrial energization were collected. Samples for ultrastructure and negative staining were taken at the end of ischemia, and after 15, 30 and 60 min of reperfusion. Hearts which were treated with the MPG-enriched cardioplegic solution showed a better ultrastructure (1 (1/1) vs 2 (2/2), p less than 0.001) and superior preservation of the mitochondrial ATPases (2.4 +/- 2.0 versus 8.4 +/- 2.7, p less than 0.05) as compared to the untreated group at the end of ischemia. At the end of reperfusion, mitochondrial respiration, and energization of the mitochondria was improved significantly with the addition of MPG as compared to the untreated group.

Does determination of serum aspartate aminotransferase contribute to the diagnosis of acute myocardial infarction?

Values for total lactate dehydrogenase (LD), LD isoenzymes, and serum aspartate aminotransferase (AST) were determined in 150 patients with acute myocardial infarction (AMI) and 130 non-AMI patients 24, 48, and 72 hours after admission. The authors assessed the diagnostic yield of a single determination of AST, LD, and three LD isoenzymes tests: LD-1 greater than LD-2; LD-1 greater than 90 U/L; LD-1/LD greater than 0.4. They also assessed the diagnostic accuracy of combined determination of AST with LD and AST with each of the above three LD isoenzymes tests. The efficiency of single determination of AST was better than that of LD (88% vs. 80%, 48 hours after admission). The most efficient single test for diagnosing AMI was the LD-1 greater than 90 U/L test (92%, 48 hours after admission). The efficiency of the combined AST/LD test was better than that of a single determination of each of the two enzymes (90% vs. 88% and 80%, 48 hours after admission). The highest efficiency was achieved, however, with combined determination of AST and any of the three LD isoenzymes tests. It was found to be more efficient than single determination of each of the LD isoenzymes tests (95.5-96% vs. 89-92.5%) and more efficient than the combined determination of the AST/LD test (95.5-96% vs. 89-90%). The authors conclude that AST should be determined in every patient with suspected AMI because its determination may contribute to the diagnostic yield of LD isoenzymes tests, especially in patients with AMI admitted 48-72 hours after onset of symptoms, when creatine kinase declined to near normal values.

Degree of myopia in relation to intelligence and educational level

Intelligence test scores and educational levels were compared for 5943 myopic and 9891 non-myopic 18-year-old men being drafted for military service in Denmark. The former were grouped by degree of myopia, in the range -0.25 diopters (D) to -7.75 D, according to the power of correcting lenses required. Myopes of all degrees had significantly higher test scores and educational levels than non-myopes. However, the relation of these two variables to degree of myopia was not linear; for both variables there were no significant differences among myopia groups in the range -2.0 to -7.75 D. Whereas factors associated with intelligence and education seem to be important in triggering the onset of myopia, they seem to be much less important in determining the degree to which myopia progresses.

Cellular immunity in lobomycosis (keloidal blastomycosis)

The cellular immune response of twelve patients from the Brazilian Amazon basin with lobomycosis were assessed. Delayed skin reaction to bacterial and fungal antigens, skin allograft rejection, and sensitization to dinitrochlorobenzene were studied. Ninety-two percent of the patients were not reactive to dinitrochlorobenzene after sensitization; skin allograft rejection occurred in an average of 17 days. Delayed skin reaction to streptococcal, staphylococcal, trichophytin and candida antigens was negative in the majority of the patients. Reactivity to mycobacterial antigens, however, was very high. The results suggest that patients with lobomycosis are partially cellular immunodeficient.

Mitochondrial sulfhydryl groups under oligomycin-inhibited, aging, and uncoupling conditions: beneficial influence of cardioprotective drugs

Uncoupling, oligomycin-inhibited, and aging/swelling conditions comprise three models for mitochondrial dysfunction. In these models, the effects of cardioprotective agents on rat heart mitochondrial membrane -SH reactivity have been studied. For -SH detection two different chromophores were used: dithionitrobenzoate (NbS2) and monobromobimane (MB). The objective of this study is to reveal the influence of three cardioprotective substances against the loss of membrane -SH reactivity: (i) The thiol reagent 2-mercaptopropionylglycine (MPG) prevents the decrease of thiols caused by carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP), aging, and oligomycin measured with MB and NbS2, and the diminution by oleate detected with MB. The small amount of MPG (6 nmol/mg protein), necessary for the protection, agrees with oligomycin sensitivity of the -SH groups concerned. (ii) The active metabolite of molsidomine, 3-morpholinosydnonimine (SIN-1), protects against the decrease of thiols by FCCP, oleate, and aging monitored with MB. In the case of oligomycin -SH groups accessible to NbS2 are protected. (iii) Another antianginal drug, isosorbidedinitrate (ISDN) does not protect membrane thiol groups. In contrast to SIN-1, ISDN probably requires enzymatic activation. It is suggested that MPG as well as SIN-1 may help to restitute the original -SH status of the mitochondrial membrane.

Reactivity of mitochondrial sulfhydryl groups toward dithionitrobenzoic acid and bromobimanes under oligomycin-inhibited and uncoupling conditions

Thiol reactivity was determined in rat heart mitochondria using chromophores of differing polarities: monobromobimane (MB), dithionitrobenzoate (NbS2), and bromobimane-q (MQ). The purpose of this study is to correlate reaction rates of protein thiols in the mitochondrial membrane with the oligomycin-inhibited and uncoupled states: In all cases investigated the reactivity of -SH groups toward MB decreases under the above conditions. In parallel with an increase of their uncoupling activities the uncouplers reduce the reaction rate of thiol groups toward NbS2 and, progressively, toward MQ, indicating differences in sensitivity of thiol groups to uncouplers depending on the polarity of the environment. The pattern of -SH reactivity under inhibition by oligomycin resembles that of carbonylcyanide-p-trifluoromethoxyphenylhydrazone. Functional changes of the mitochondrial membrane probably correlate with reactivity/polarity changes of membrane -SH groups. Masking of membrane thiol groups thus is not specific for uncouplers but is also observed under inhibition with oligomycin.

Elevated serum creatine kinase levels. An early diagnostic sign of acute dissection of the aorta

Twenty-two patients suffering from acute dissection of the aorta were analyzed for their serum creatine kinase levels within six hours of onset of acute chest pain. Elevated serum levels were found in 14 patients (64%). In five patients, creatine kinase isoenzyme analysis was performed. These five patients showed more than 95% creatine phosphokinase MM isoenzyme of the total creatine kinase level. The finding of elevated levels of total creatine kinase in patients presenting with acute chest pain does not exclude acute dissection of the aorta. Determination of creatine kinase isoenzymes may be helpful in the differential diagnosis of acute chest pain.

The efficiency of lactate dehydrogenase isoenzyme determination for the diagnosis of acute myocardial infarction

Values for total lactate dehydrogenase (LDH; EC 1.1.1.27) activity and LDH isoenzymes 1 and 2 were determined in 80 patients with acute myocardial infarction (AMI) and in 40 without AMI every 24 hours up to 15 days after admission, when total serum LDH level returned to normal. The sensitivity, specificity, and efficiency of three LDH isoenzyme factors (LDH-1, greater than 90 U/L; LDH-1 greater than LDH-2; LDH-1/LDH ratio, greater than 0.4) for diagnosing AMI were assessed in three groups of patients according to total serum LDH values--group A, LDH level over 600 U/L; group B, 400 to 599 U/L; group C, 225 to 399 U/L--and in five groups of patients according to the time after admission--(1) first 48 hours; (2) three to five days; (3) six to eight days; (4) nine to 11 days; (5) 12 to 15 days. All three factors were found to be highly efficient for diagnosing AMI (91.5% to 97.5%) in groups A and B, but the most efficient factor in each group was LDH-1 value above 90 U/L. In group C, the only efficient factor was the LDH-1 value over 90 U/L (96%). The most efficient factor for diagnosing AMI in relation to time after admission up to 15 days after AMI was the LDH-1 value over 90 U/L (96% to 97.5%). The factors LDH-1 greater than LDH-2 and LDH-1/LDH above 0.4 were more efficient in patients up to five days after AMI (91.5% to 97.5%) than in patients six to 15 days after admission. We conclude that the most efficient LDH value for diagnosing AMI is the absolute value of LDH-1 above 90 U/L. Its superiority over other LDH isoenzyme values is best documented in a group of patients six to 15 days after admission and with only slight to moderate elevation of total serum LDH values (225 to 399 U/L).

Patterns of lactate dehydrogenase isoenzymes in serum of patients with acute pulmonary edema

Total lactate dehydrogenase (LD; EC 1.1.1.27) activity in serum and proportions of LD isoenzymes were quantified on admission and discharge in 170 selected (from 240) patients with acute pulmonary edema (APE). The patients were divided into group A, 75 patients with normal LD values (less than 225 U/L); and groups B-E, with increased LD activity in serum: group B, 40 patients with increase in the proportion of LD-3 (greater than 38%); group C, 12 patients with increased LD-5; group D, 36 patients with an isomorphic pattern of LD isoenzymes; and group E, seven patients with LD-1/LD-2 greater than 0.75. Nine patients in group C (75%) had also signs of right-sided congestive heart failure, 30 in group D (83%) had hypotension on admission, and six in group E (86%) had signs of recent myocardial infarction. Evidently, half of patients with APE may show increased total LD activity in serum at the time of admission. LD isoenzyme proportions should be determined in such patients, because there is no one typical pattern of LD isoenzymes and some LD isoenzyme patterns may be associated with specific clinical situations.

Patterns of lactate dehydrogenase isoenzymes in serum of patients with acute pulmonary edema

Total lactate dehydrogenase (LD; EC 1.1.1.27) activity in serum and proportions of LD isoenzymes were quantified on admission and discharge in 170 selected (from 240) patients with acute pulmonary edema (APE). The patients were divided into group A, 75 patients with normal LD values (less than 225 U/L); and groups B-E, with increased LD activity in serum: group B, 40 patients with increase in the proportion of LD-3 (greater than 38%); group C, 12 patients with increased LD-5; group D, 36 patients with an isomorphic pattern of LD isoenzymes; and group E, seven patients with LD-1/LD-2 greater than 0.75. Nine patients in group C (75%) had also signs of right-sided congestive heart failure, 30 in group D (83%) had hypotension on admission, and six in group E (86%) had signs of recent myocardial infarction. Evidently, half of patients with APE may show increased total LD activity in serum at the time of admission. LD isoenzyme proportions should be determined in such patients, because there is no one typical pattern of LD isoenzymes and some LD isoenzyme patterns may be associated with specific clinical situations.

Significance of isolated increases in total lactate dehydrogenase and its isoenzymes in serum of patients with bacterial pneumonia

Total lactate dehydrogenase (LD, EC 1.1.1.27) activity in serum and LD isoenzymes were quantified at the time of diagnosis in 320 patients with bacterial pneumonia. In eighty, LD activity was increased, but this was accompanied by either other pathological results for liver-function tests or associated diseases that could explain it. The remaining 240 patients were divided into four groups, based on their total serum LD values: group A, less than 225 U/L (normal limit); group B, 226-350 U/L; group C, 351-499 U/L; and group D, greater than 500 U/L. Total LD was above normal at diagnosis in 40% of the patients. Recovery time was twice as long in group D as in groups A, B, and C. In five patients from group D, the pneumonia reflected underlying lung cancer. In groups B and C, the LD-3 ratio was increased in comparison with group A; in group D, LD-4 and LD-5 were increased up to twice the normal limit. Evidently nearly half of patients with bacterial pneumonia may show isolated increases in total LD activity (mostly LD-3) in serum. In cases with high activity, prolonged recovery time is expected. Intensive follow-up and extensive investigation are warranted in these patients, because some may have underlying lung cancer.

Isolation and partial characterization of insulin of the honeybee (Apis mellifica)

In the honeybee (Apis mellifica), insulin-like material was partially purified with acid ethanol extractions by a classic method for recovering insulin and following gel filtration on a Sephadex G-50 column. The preparations were characterized by their ability to cross-react with porcine insulin antibodies. Insulin-like biological activity was demonstrated using the insulin bioassay. Stimulation of glucose oxidation or lipogenesis was measured by isolated rat adipocytes. Insulin seems to be more widespread in invertebrates than was previously assumed.

Significance of isolated increases in total lactate dehydrogenase and its isoenzymes in serum of patients with bacterial pneumonia

Total lactate dehydrogenase (LD, EC 1.1.1.27) activity in serum and LD isoenzymes were quantified at the time of diagnosis in 320 patients with bacterial pneumonia. In eighty, LD activity was increased, but this was accompanied by either other pathological results for liver-function tests or associated diseases that could explain it. The remaining 240 patients were divided into four groups, based on their total serum LD values: group A, less than 225 U/L (normal limit); group B, 226-350 U/L; group C, 351-499 U/L; and group D, greater than 500 U/L. Total LD was above normal at diagnosis in 40% of the patients. Recovery time was twice as long in group D as in groups A, B, and C. In five patients from group D, the pneumonia reflected underlying lung cancer. In groups B and C, the LD-3 ratio was increased in comparison with group A; in group D, LD-4 and LD-5 were increased up to twice the normal limit. Evidently nearly half of patients with bacterial pneumonia may show isolated increases in total LD activity (mostly LD-3) in serum. In cases with high activity, prolonged recovery time is expected. Intensive follow-up and extensive investigation are warranted in these patients, because some may have underlying lung cancer.

Atypical patterns of lactate dehydrogenase isoenzymes in acute myocardial infarction

Total lactate dehydrogenase (LD; EC 1.1.1.27) activity in serum and LD isoenzymes were quantified in 190 patients with acute myocardial infarction (AMI) 24, 48, and 72 h after admission. In 90% of the 570 blood specimens an LD isoenzyme pattern typical of AMI (LD-1/LD-2 greater than 0.76) was found. The other 56 blood specimens showed an LD isoenzyme pattern atypical of AMI (LD-1/LD-2 less than 0.76). They were divided into three groups: 28 specimens with isomorphic pattern (relative increase in all five LD isoenzymes); 18 with relatively increased LD-3 proportion (greater than 35%); and 10 specimens with increased LD-5 proportion (greater than 10%). No difference was found in mean total LD activity in serum between the typical isoenzyme group and the three atypical groups. The LD isomorphic pattern was found in 60% of AMI patients complicated by cardiogenic shock. Fifty percent of AMI patients admitted with pulmonary edema showed increased LD-3 proportion and half of the patients with AMI and congestive heart failure, predominant right, demonstrated increased LD-5 proportion. We conclude that although most patients with AMI present at diagnosis with a typical LD isoenzyme pattern, it is important to recognize that some may present with atypical LD isoenzyme patterns, which may be associated with specific AMI complications.

Atypical patterns of lactate dehydrogenase isoenzymes in acute myocardial infarction

Total lactate dehydrogenase (LD; EC 1.1.1.27) activity in serum and LD isoenzymes were quantified in 190 patients with acute myocardial infarction (AMI) 24, 48, and 72 h after admission. In 90% of the 570 blood specimens an LD isoenzyme pattern typical of AMI (LD-1/LD-2 greater than 0.76) was found. The other 56 blood specimens showed an LD isoenzyme pattern atypical of AMI (LD-1/LD-2 less than 0.76). They were divided into three groups: 28 specimens with isomorphic pattern (relative increase in all five LD isoenzymes); 18 with relatively increased LD-3 proportion (greater than 35%); and 10 specimens with increased LD-5 proportion (greater than 10%). No difference was found in mean total LD activity in serum between the typical isoenzyme group and the three atypical groups. The LD isomorphic pattern was found in 60% of AMI patients complicated by cardiogenic shock. Fifty percent of AMI patients admitted with pulmonary edema showed increased LD-3 proportion and half of the patients with AMI and congestive heart failure, predominant right, demonstrated increased LD-5 proportion. We conclude that although most patients with AMI present at diagnosis with a typical LD isoenzyme pattern, it is important to recognize that some may present with atypical LD isoenzyme patterns, which may be associated with specific AMI complications.

Pyruvate carboxylase from Pseudomonas citronellolis: shape of the enzyme, and localization of its prosthetic biotin group by electron microscopic affinity labeling

Pseudomonas citronellolis is known to contain a pyruvate carboxylase with an alpha 4 beta 4 composition. All the other pyruvate carboxylases investigated so far are made up of four seemingly identical subunits. Nevertheless, this exceptional pyruvate carboxylase exhibits a size and overall shape similar to other pyruvate carboxylases. Electron microscopic affinity labeling with avidin revealed that the prosthetic biotin groups (one per alpha beta unit, i.e. four per enzyme particle) are located close to the inter-unit junctions of pairs of alpha beta units making up the enzyme. This position of the prosthetic biotin groups is very similar to the location of the biotin in the other carboxylases.