Elevation of brain-type creatine kinase in serum from patients with carcinoma

Creatine Kinase-BB Activity in Malignant Tumors and in Sera from Patients with Malignant Diseases

Creatine kinase (CK EC 2.7.3.2) and CK-BB activity was analyzed in 41 malignant tumors of 6 different sites and different histological structures. The same analyses were done on 150 sera of patients with malignant diseases of various localizations. The rate of CK activity was determined kinetical-ly, whereas tissue and serum CK-BB were separated chromatographically (Mercer). Insofar as malignant tumor tissues are concerned, the highest average rate of CK-BB activity was detected in tumors of the prostate (mean 1450 IU/g), and the lowest in tumors of the parotid gland (mean 5.2 IU/g). CK-BB was detected by the Mercer technique in 56 (37.3 %) of 150 analyzed sera of patients with malignant diseases. The rate of CK activity in sera of patients with malignant diseases was 8 to 74 IU/I. In comparison with the site of the malignant process no significant CK serum activity differences were observed. T2-T3 tumors did not significantly influence the activity of either CK or CK-BB in the case of either tissues or sera (T1-T3). Enzyme activity was found to be much higher - both in tumoral tissue and in sera - with T4 tumors. The highest rate of CK-BB activity was found in sera of patients with malignant tumors of the stomach (mean 8.1 IU/I), and the lowest in malignant tumors of the rectum (mean 1.8 IU/I).

Serum creatine kinase isoenzymes in patients with advanced malignant disease

Serum creatine kinase (CK) B subunit (CK-B) activity, as estimated by the enzymatic anti-M immunoinhibition method, and the CK isoenzyme pattern after agarose gel electrophoresis, were studied in 28 patients with advanced, untreated malignant disease. CK-B was above the decision limit, i.e. the discrimination limit used in the diagnosis of acute myocardial infarction (AMI), in 14 patients (50%). Electrophoresis demonstrated, besides CK-MM, an atypical, cathodically migrating CK band in 10 of these patients. This band may represent mitochondrial CK. The CK-BB isoenzyme was detected in 9 and CK-MB in 3 subjects. Histopathologic findings indicated that the occurrence of these isoenzymes was related to tumour burden and the overall severity of the disease. Survival among patients with CK-B elevation was shorter than among other patients. The present findings are relevant to the enzyme diagnosis of AMI and of potential significance for the evaluation of patients with known or suspected malignant tumours.

Serum creatine kinase elevation in a medical department

Serum creatine kinase (CK) levels are diagnostic markers for acute myocardial infarction. Many other causes however, including neuromuscular disorders, may induce serum CK elevation as well. Aim of the study was to investigate the prevalence of potential causes for serum CK elevation in a medical department. In particular we were interested in the recognition of patients in whom serum CK elevation was due to a neuromuscular disorder. Included in this prospective study were 100 consecutive patients in whom the CK level, determined at admission, was increased (> 70 IU/l in female, > 80 IU/l in male patients). After admission we looked for the presence of causes known to induce CK elevation. Patients with no potential cause for CK elevation were invited for follow-up investigations three months later. If no potential cause could be found and if CK was elevated again on this occasion, the patient was referred for a comprehensive neurological investigation. The prevalence of patients with CK elevation was 11.2%. The 100 patients (44 female, 56 male) were aged from 23 to 94 (mean 67) years. In 95% CK elevation was only up to 500 IU/l. The most frequent cause for serum CK elevation was acute myocardial infarction in 32%. Further frequent causes were drug intake (32%), fall (24%), haematoma (17%), intramuscular injection (16%) and malignancy (11%). In 61% of the cases at least two potential causes for serum CK elevation could be detected. Neuromuscular disorders were found in only 2%. This study shows that serum CK elevation occurs in 11% of patients admitted to a medical department and can be explained by acute myocardial infarction in only 32%. In almost two thirds of the patients, more than one potential cause for serum CK elevation can be found thus making CK elevation a rather unspecific finding. Neuromuscular disorders are rarely found as a cause of serum CK elevation in a medical department.

A complete system for identifying inhibitors of creatine kinase B

We have developed a complete system for discovery of lead compounds as inhibitors of creatine kinase B. In this article, we describe production and purification of the recombinant protein, conditions and features of an optimized high-throughput screening assay, and results of our implementation of the system using a diverse compound library.

Chronic creatine kinase elevation not associated with HMG-CoA reductase inhibitor treatment

OBJECTIVE

To report a case of chronically elevated creatine kinase (CK) concentration that is possibly associated with renal insufficiency and prostatic carcinoma. The goal is to raise awareness among clinicians who monitor CK concentrations in patients receiving hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors.

CASE SUMMARY

Because of an elevated CK concentration, a 64-year-old African-American man with a history of chronic heart disease and renal insufficiency was assessed for possible myositis relating to his treatment with HMG-CoA reductase inhibitors. However, an association between the elevated enzyme concentration and drug treatment could not be clearly established. The patient was subsequently diagnosed with prostatic cancer and underwent a radical retropubic prostatectomy. The CK enzyme concentration declined following the surgery despite continuation of the drug therapy.

DISCUSSION

CK is relatively nonspecific because of its wide distribution in human tissues. Although several findings of elevated CK concentrations, particularly the CK-BB isoenzyme, in patients with carcinoma or chronic renal insufficiency have been documented, these may not be common knowledge among clinicians. This case report provides an example of an unusually high CK enzyme concentration that may be linked to prostatic carcinoma and renal insufficiency.

CONCLUSIONS

It is important to be aware of different causes for CK enzyme concentration elevation, especially when it is used as a monitoring parameter during HMG-CoA reductase inhibitor treatment. In a case of persistent elevated CK enzyme concentration without evidence of myositis, renal insufficiency may be a contributing factor and malignancy must be ruled out.

Creatine kinase activity and isoenzymes in lung, colon and liver carcinomas

We have compared the levels of creatine kinase (CK) activity and the distribution of CK isoenzymes determined by agarose gel electrophoresis in normal colon, liver and lung tissues, and in colon, liver and lung adenocarcinomas, lung squamous cell carcinomas and lung carcinoids. Colon and lung adenocarcinomas, and squamous cell carcinomas presented lower CK activity than the normal tissues and no differences were found between hepatocarcinoma and normal liver tissue. In contrast, lung carcinoids had higher CK activity than normal lung tissue. Type BB-CK was the predominant isoenzyme in normal lung, colon and liver tissues. Type MM isoenzyme was detected in normal lung and type MB-CK was found in normal colon. In most lung tumours the CK isoenzyme electrophoretic pattern did not change. However, no type BB-CK was detected in some hepatocarcinomas, type MM-CK decreased in lung carcinoids and type MB isoenzyme was not observed in colon adenocarcinomas. It is concluded that in most tumours there is a decrease in the expression of type B- and type M-CK subunits, whereas in lung carcinoid the expression of type B-CK activity increases. Thus, the increase in type BB-CK observed in the serum of patients with lung and colon adenocarcinomas is probably due mainly to enhanced enzyme release as a result of tumour cell necrosis.

Quantification of creatine kinase BB isoenzyme in tumor cytosols and serum with an ultrasensitive time-resolved immunofluorometric technique

OBJECTIVES

To develop a highly sensitive immunofluorometric procedure for creatine kinase BB isoenzyme and use it to measure CK-BB in tumor cytosolic extracts and serum of cancer patients and healthy volunteers.

DESIGN AND METHODS

For assay development, we used two monoclonal antibodies in combination with time-resolved fluorometry and the biotin-avidin system. We measured CK-BB in breast tumor cytosols and studied its association with steroid hormone receptors. We also measured CK-BB in the serum of healthy subjects and patients with prostate cancer. We have examined the molecular weight of CK-BB in serum using high performance liquid chromatography.

RESULTS

The evaluation of the method revealed good precision and accuracy. Study of 336 breast tumor cytosols and 9 normal breast cytosols has shown that CK-BB is overexpressed by 95% of breast tumors and that CK-BB is present in its 80 kDa form. A close association between CK-BB and estrogen but not progesterone receptors was found, suggesting that CK-BB overexpression is another marker of estrogen sensitivity of these tumors. Previous studies, using CK-BB radioimmunoassay could not detect CK-BB in the serum of about 50% of healthy subjects. We have assessed CK-BB levels in 80 male volunteers, detected CK-BB in all sera and provided a detailed distribution of values. We further demonstrated that 30% of prostate cancer patients in remission (PSA < 0.4 microgram/L) post radical prostatectomy and 50% of patients with active prostate cancer (PSA > 20 microgram/L) have elevated serum CK-BB levels. The patients with highly elevated CK-BB also had highly elevated serum PSA. We have demonstrated that some patients who have elevated serum CK-BB also have macromolecular CK complexes in their serum with molecular weights of 700 and 350 kDa as well as the 80 kDa CK-BB isoenzyme. Only the latter was recognized by the assay developed.

CONCLUSIONS

CK-BB is a marker of estrogen sensitivity in breast cancer; Patients with prostate cancer have elevated CK-BB in their serum; The new highly specific and sensitive assay may be further used to study the role of CK-BB in various malignancies.

Concomitant monitoring of serum neuron-specific enolase and creatine kinase BB in small cell lung cancer

Serum neuron-specific enolase (NSE) and serum creatine kinase isoenzyme BB (CK-BB) were measured in 43 small cell lung cancer (SCLC) patients. The overall sensitivity of NSE (greater than 12.5 ng/ml) was 65%; in limited disease (LD) 48% and in extensive disease (ED) 100%. CK-BB was detected in 14 patients (32%); the sensitivity was 17% in LD and 64% in ED. During treatment NSE declined or stabilized to normal level in LD together with objective response in 75% (21/28), and rose again with progression in 28% (6/21). CK-BB fell to normal in all 5 patients with LD, in 3 of them with objective response. In ED elevated NSE and CK-BB declined to normal with objective response in 73% (8/11) and in 25% (2/8) of the evaluable patients respectively. We conclude that serum NSE is a potential marker for staging and response monitoring in SCLC, but that CK-BB gives additional information of limited value.

Elevated creatine kinase and malignancy

Increased serum levels of CK isoenzymes variously signal heart, brain, or skeletal muscle damage. They may also be markers for advanced tumors with poor prognosis.

The diagnostic and prognostic value of pretreatment serum creatine kinase BB levels in patients with neuroblastoma

The serum levels of the BB isozyme of creatine kinase (CK-BB) and neuron-specific enolase (NSE) were measured before therapy in 35 patients with neuroblastoma. Sixty percent (21 of 35) of neuroblastoma patients had CK-BB levels higher than 11 ng/ml. The extent of disease was associated with an increased incidence of elevated serum CK-BB levels. The highest pretreatment serum CK-BB titers were found in patients with Stage IV disease. A strong correlation between the pretreatment CK-BB level and the outcome in patients with neuroblastoma was observed. Eleven (79%) of 12 patients who had a serum CK-BB level greater than 15 ng/ml died, and eight of ten (80%) who had a serum level less than 11 ng/ml were alive and tumor free after 2 years. A positive linear correlation between the pretreatment CK-BB and NSE (n = 35, r = 0.695) levels was found.

Non-M CK--a practical measure of creatine kinase isoenzymes in cancer patients

The individual creatinine kinase (CK) isoenzymes CK-BB and CK-Macro II have previously been investigated as potential tumour markers. We believe there is a need for a system to measure those CK forms not usually present in serum. We have studied a CK-MB immunoinhibition kit which measures all residual CK activity following inactivation of M-subunit activity. In 162 patients with cancer we found no difference in grading (+ or -) between detailed isoenzyme studies and the simple non-M assay. In 33 samples with elevated non-M CK, detailed analysis showed BB alone (45%), Macro II alone (9%), or both (36%). Raised activities were mainly found in patients with small cell lung cancer (SCLC) (17/40; 43%) and GI Tumours (6/11; 55%). In patients with SCLC, elevated activities were associated with disseminated disease. Preliminary evidence indicates that Non-M CK may also be a simple means of monitoring initial treatment response.

Serum CK-BB as a tumor marker in patients with carcinoma confirmed histologically

We determined serum CK-BB mass concentration using a specific RIA method, in 267 patients with carcinoma confirmed histologically distributed as follows: 46 prostatic adenocarcinoma, 52 lung neoplasies, 70 colon carcinoma, 52 breast carcinoma and 41 gastric carcinoma; and also in 135 patients with histologically proved non-neoplastic diseases distributed as follows: 28 prostatic hyperplasy, 31 lung tuberculosis, 29 inflammatory bowel disease, 27 fibrocystic mastopathy and 20 gastroduodenal ulcer. Reference values in healthy subjects (n = 360) were 5.46 +/- 2.68 (SD) ng/ml. We found that serum CK-BB mass concentration is not a specific tumor marker but it is a valuable indicator of responsing to therapy and metastatic widespread. However, in prostatic carcinoma--prevalence 0.25, predictive positive value (PPV) 0.51 and predictive negative value (PNV) 0.88--and breast carcinoma--prevalence 0.32, PPV 0.60 and PNV 0.87--serum CK-BB can be used as a tumor marker. Only 12 over 268 patients with different neoplastic disease (4.47%) showed detectable serum CK-BB catalytic concentrations.

Clinical value of an amplified electrophoretic determination of enolase isoenzymes in small cell lung carcinoma patients

Neurone specific enolase (NSE); alpha gamma and gamma gamma isoenzymes of the glycolytic enzyme enolase, is found in considerable quantity in serum of patients with small cell lung cancer (SCLC). The spectrophotometric measurement of serum enolase activity, plus the electrophoretic separation of isoenzymes (alpha alpha, alpha gamma and gamma gamma) using an amplification reaction constitute a simple method, the application of which has not yet been demonstrated. In patients, serum values of higher than 25 U/l of total enolase activity, with more than 10% NSE, were considered to be positive. Seventy patients diagnosed as SCLC were classified before treatment as having either limited (LD) or extensive (ED) disease, and after chemotherapy as being in complete (CR) or partial remission (PR), stable state (SS) or in relapse (R). The levels of enolase activity and NSE (M +/- SE) in these patients (enolase: 67 +/- 7 U/l, NSE 27 +/- 2%) were different from those in a control group of 19 patients with non-small cell lung cancer (enolase: 29 +/- 2 U/l, NSE: 7 +/- 1%) (p less than 0.001) at the time of diagnosis. Mean enolase and NSE levels in patients with SCLC were seen to differ significantly according to the clinical stage. The results of those patients with ED differed from those of patients with LD (p less than 0.001). The results of the group of patients that achieved remission differed from that of patients during relapse (p less than 0.0001). Serial measurements demonstrated a good correlation between enolase and NSE serum levels and the progression of the disease. The usefulness of this method in the early assessment of treatment was also demonstrated. The clinical usefulness of the dosage of NSE with that of two other tumour markers CKBB and mitochondrial CK was compared.

Creatine Kinase Isoenzyme BB: A Lung Cancer Associated Marker

We investigated the diagnostic role of creatine kinase isoenzyme BB (CK-BB) in lung cancer. CK-BB was assayed using a radioimmunological system by saturation with Mallinchrodt double antibody 125I labelled (RIA Quant-CPK-BB).

Sensitivity was 97% and specificity 90% in 44 cancers (T2-T3), in 36 non-cancers (chronic bronchitis) and in 48 healthy controls.

Mean serum CK-BB values for patients with chronic bronchitis (2.64 ± 1.1 ng/ml) were virtually the same as in normal subjects. Patients with lung cancer had markedly higher serum CK-BB values (9.17 ± 2.6 ng/ml) than either the control group (healthy subjects) or the chronic bronchitis patients (p < 0.01). These results lead us to suggest that CK-BB serum determination might prove useful in screening pulmonary disorders. However, further studies are essential to establish: 1) the relationship between serum levels of the isoenzyme and the histology and stage of the neoplastic disease; 2) the relation between CK-BB and the aggressive potential of the neoplastic clone.

Determination of creatine kinase isozymes in sera and tissues of patients with various lung carcinomas

Three creatine kinase isozymes (CK-BB, CK-MB and CK-MM) were estimated by immunoassay in tumor tissues and in sera of patients with various lung carcinomas. CK-BB was increased in small cell carcinoma, but not in other lung carcinomas. CK-MM and CK-MB were not increased in any types of carcinoma. Serum CK-BB was increased in all types of lung carcinoma examined, while serum CK-MM and CK-MB were within normal limits in all patients. Serum CK-BB of healthy adults was estimated as 0.32 +/- 0.14 (mean +/- SD) ng/ml, ranging from 0.11-0.68 ng/ml. If CK-BB values above 1.0 ng/ml were considered abnormal, elevation occurred in 28/40 (70%) of patients with small cell carcinoma, 25/67 (37%) with adenocarcinoma, 21/51 (41%) with squamous cell carcinoma, 4/11 (36%) with other carcinoma of the lung and 10/42 (24%) with lung tuberculosis. Since serum CK-BB with lung cancer changed in parallel with the clinical course, this isozyme may be a marker for monitoring the clinical course, especially in small cell carcinoma of the lung.

Enteric coronavirus in symptomless homosexuals

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Myelin basic protein and creatine kinase BB isoenzyme as CSF markers of intracranial tumors and stroke

In patients with intracranial tumors (ICT) and acute cerebral infarctions (CI), both necrosis and reversible changes occur in central nervous system (CNS) tissue. The damaged CNS cells release specific substances into the cerebrospinal fluid (CFS). Radioimmunoassay (RIA)-determined myelin basic protein (MBP) and RIA-determined creatine kinase BB (CK-BB) are markers of damage to CNS specific structures. The elevated CSF level of MBP is considered a marker of myelin damage and the increased concentration of CSF CK-BB may be of combined neuronal and astrocytic origin. CSF was collected from 57 patients with the diagnosis of CI (n = 30) and ICT (n = 27) and the concentration of MBP and CK-BB were measured by RIA. Our study shows increased CSF levels of MBP and CK-BB in patients with CI and patients with ICT. We have also found a linear correlation between MBP and CK-BB in both CI and ICT, and for a given CK-BB level, MBP was significantly higher in patients with ICT than in patients with CI. These facts suggest that lesion markers behave differently in the different pathologic processes affecting the CNS.

Creatine kinase and its isoenzymes in neoplastic disease

The CK-BB isoenzyme is ubiquitous in neoplastic tissue, but with low activity. Accordingly, it might be a nonspecific and insensitive tumor marker. Evaluation of BB isoenzyme in serum might indicate the extent of diseases or the response to therapy. The presence of CK-MB in patients with cancers may cause confusion with AMI. Serial determinations of both CK and lactate dehydrogenase isoenzymes are of great help in differential diagnosis. The presence of mit-CK is a poor prognostic sign in patients with malignancy. The greatest clinical significance of CK-BB and macro-CK isoenzyme lies in their effect on various assays for CK-MB. Macro-CK types 1 and 2 are much more heat stable than are CK-MB and CK-BB, and so by heating samples for 20 min at 45 degrees C the presence of thermostable macro types can be demonstrated. Macro-CK type 2 has a much higher activation energy than macro-CK type 1. If macro-CK is present, determination of the activation energy easily differentiates between types 1 and 2. CK-Bi seems to be glycosylated protein, and it is thought that glycosylation may be a general way of enzyme inactivation. If inactivation inside the cell is postulated, it has to be shown that enzymes indeed pass into the cell compartments where glycosylating enzymes are located. Another possible mechanism is within the circulation. Whether malignant cells themselves produce Ck-Bi or if inactivation occurs in the blood is still unknown. In this connection, one finding is that in plasma of cancer patients, CK-Bi can be reactivated to CK-BB by mercaptoethanol to 95%, whereas in plasma of normal persons there is no reactivation of the much lower CK-Bi concentrations.

Serum creatine kinase BB isoenzyme as a diagnostic aid in occult small cell lung cancer

Four patients with metastatic small cell carcinoma of the lung who had initial chest x-rays that did not reveal the cancer showed striking elevations of serum creatine kinase BB isoenzyme, which suggested the diagnosis and directed the subsequent evaluation. Creatine kinase BB isoenzyme elevation with widespread small cell carcinoma of the lung is probably more common than currently recognized, and is a useful diagnostic indicator for extensive stage small cell lung cancer, even in the absence of central nervous system metastases.

Elevated CK-MB and CK-BB in serum and tumor homogenate of a patient with lung cancer

Elevated serum levels of creatine kinase (CK) were found in a patient with small-(oat) cell carcinoma of the lung. Fractionation of the enzyme showed markedly elevated CK-MB and CK-BB isoenzymes. Clinical and subsequent pathological examination showed no evidence of infarction, inflammation, or tumor involvement of the heart; however, analysis of tumor tissue for CK showed predominance of CK-MB and CK-BB isoenzymes, thus implicating tumor as the source of the circulating levels of CK-MB and CK-BB. Our case is the first to document CK-MB from neoplastic tissue homogenates, and illustrates that markedly elevated circulating levels of CK-MB, or increased levels of CK-MB in combination with CK-BB may point away from a myocardial source, and toward the existence of a malignancy.

Creatine kinase isoenzyme (CK-BB) by RIA as a follow-up marker in stage D cancer of the prostate: comparison with PAP RIA

Fifty-nine patients with stage D carcinoma of the prostate under different modalities of treatment were studied for creatine phosphokinase isoenzyme BB (CK-BB) and prostatic acid phosphatase (PAP) levels in serum by radioimmunoassay (RIA) technique, in order to study the possible use of CK-BB as a follow-up marker compared to PAP. Thirty-three patients were in stable, 19 in progressive, and seven in regressive clinical state. CK-BB was above normal level in 52 (88%) out of 59 patients with no statistically significant difference between the three clinical states. On the other hand, PAP was above normal level in only 23 patients (38.98%) with statistically significant difference between the three clinical states (P less than 0.001). The PAP/CK-BB index was below 1 in stable and regressive condition, while it was above 1 in eight out of 19 patients with progressive disease. The PAP/CK-BB index may be of prognostic importance. CK-BB by RIA was abnormal in more cases than PAP. In this way CK-BB reflects the presence of the tumor and may be used for diagnosis; however, it does not reflect the clinical response as PAP does.

Creatine phosphokinase isoenzymes in human prostatic tissues: a comparison between benign hyperplasia and adenocarcinoma

The objective of this study was to determine the distribution of creatine phosphokinase (CPK) into its three isoenzymes, MM, MB, and BB, in human prostatic tissue, in patients with benign hyperplasia (BPH) and adenocarcinoma. Specimens were obtained from 23 patients with adenocarcinoma of the prostate and 25 patients with benign hyperplasia. We also had the opportunity to analyze the CPK content in two normal prostates, the first from a 16 1/2-year-old boy and the second from a 9 1/2-year-old child. Our results showed prostate tissue to contain almost exclusively the BB isoenzyme with traces of the MB and MM dimers in both cancer and BPH as well as the specimen of normal prostate from the 16 1/2-year-old boy. As for the 9 1/2-year-old child, we found the following distribution: 39% MM, 21% MB, and 40% BB dimer. A comparison of the CPK-BB content in benign hyperplasia and adenocarcinoma revealed no significant difference between the two groups. Furthermore, we tried to correlate prostatic tissue CPK-BB levels with another possible tumor marker of the prostate, prostatic acid phosphatase (PAP) measured in the cytosol. No correlation was found between these two markers. We also studied the relationship of CPK-BB and PAP content in prostatic tissue to nuclear and cytosolic androgen receptor content in human prostatic tissue. We found some correlation between CPK-BB and androgen cytosolic receptors as well as between PAP content and androgen cytosolic receptors in patients with benign hyperplasia. No such correlation was found in the group with adenocarcinoma. In conclusion, this study does not show that the measurement of CPK-BB in the prostatic tissue could be used as an index of tissue malignancy.

Creatine kinase isoenzymes and prostatic carcinoma: metastatic disease or acute myocardial infarction?

The measurement of creatine kinase isoenzymes, particularly the MB fraction, is a major determinant for acute myocardial infarction. Patients with metastatic carcinoma of the prostate may have an elevated serum creatine kinase-BB fraction, which by some automated laboratory techniques may be read mistakenly as creatine kinase-MB. We report such a case and discuss the creatine kinase isoenzyme measurement.

Sialyltransferase activity in tumor tissues

Sialyltransferase (ST) activity was examined in tumor and control tissues. Within each group of control tissues a wide variation in the levels of ST activity was observed. Only in 20% of the tumors was the ST activity above the range of enzyme activity of the corresponding group of control tissues. Compared with its corresponding normal counterpart from the same individual, ST was elevated in tumor tissue by a factor of 2.1 on average. The distribution function indicates an increase in enzyme activity in 74% of the tumors. Other tumor markers were also determined for comparison. The ratio of the lactate dehydrogenase (LDH) subunits (M/H) was increased in tumors by a factor of 1.3 on average; the frequency of increase was 75%. From the distribution function of our data it follows that a decrease in the ratio of the creatine kinase (CK) subunits (B/M) occurs in 56% of tumors, the average factor being 0.8. The Regan isoenzyme of the alkaline phosphatase (AP) could be demonstrated in 13% of the tumors. In serum and in tissues ST was found to be composed of multiple forms. However, an isoenzyme of higher tumor specificity has not yet been established.

The mechanisms relating to increases in plasma enzymes and isoenzymes in diseases of animals

Changes in plasma or serum enzymes and isoenzymes are useful indicators of tissue damage in many diseases. Enzyme increases are usually related to leakage of enzymes from damaged cells. The amount of increase depends on factors such as the concentration of enzyme in the cells, the rate of leakage of enzyme from cells and the rate of clearance of enzyme from plasma. There are important species variations in the tissue concentrations and plasma clearance rates of enzymes and isoenzymes.

Alterations of creatine kinase isoenzymes in colon washings from patients with colonic and rectal diseases

Mucus samples obtained from 61 patients with different types of colon and rectal disease were assayed for CK isoenzyme fractionation. Twelve additional patients without evidence of such diseases were used as reference subjects. The diseases surveyed were hemorrhoids, proctocolitis, polyps, and cancer of the colon and rectum. The CK BB fraction was predominant in the mucus of the reference subjects and in mild cases of hemorrhoids and polyps. With inflammation of degeneration of the colonic mucosa, the present CK BB decreased and the percent of CK MM increased. It is speculated that the increased CK MM possibly derives from increased permeability of degeneration of the colonic wall, permitting plasma CK MM to admix with the mucus. Mucin CK isoenzyme fractionation may be useful in assessing the pathogenesis of colonic and rectal diseases, as a marker to monitor the efficacy of the therapeutic regimen, and as a technique for monitoring conversion of a premalignant process into a malignant one.

Creatine kinase from the bovine myometrium: purification and characterization

Creatine kinase from the smooth muscle of the cow uterus was extracted and purified by procedures involving precipitation of the enzyme in the presence of ethanol, cation exchange chromatography on phosphocellulose, gel filtration in Sephadex G-150 and anion exchange chromatography on DEAE-cellulose. The purified enzyme eluted as a single active peak after rechromatography on Sephadex G-150 with a molecular weight of about 82 000. Electrophoresis in polyacrylamide gels in tris-glycine buffer (pH 8.6) under non-denaturing conditions revealed a single enzymatically active protein band. In the presence of sodium dodecyl sulphate, the enzyme migrated as a single band in polyacrylamide gels at a mobility corresponding to a molecular weight of about 40 000 per subunit. Reaction with iodoacetamide indicated the presence of sulphydryl groups of differing susceptibility to alkylation. The purified enzyme was optimally active over a wide pH range (6.5-8.0). The Michaelis constants (Km) of the enzyme for MgADP and phosphoryl creatine (PCr) are 0.12 mM and 0.7 mM respectively, which are significantly lower than those for skeletal muscle CK. MgADP lowered the dissociation constant of the enzyme for PCr (from about 3.6 mM to 0.7 mM). Evidence is presented that the high affinity of the smooth muscle CK to MgADP and the MgADP-mediated facilitation of PCr binding might be key factors in the role of this enzyme in harnessing the energy reserves of the cell.

Anomalous creatine kinase isoenzymes in serum from patients with rectal carcinoma

Sera from eight patients with biopsy-proven rectal carcinoma were assayed for creatine kinase (CK). Two of the patients had enzyme activity: one with the BB and the other with an MB isoenzyme. We think that our results may be of interest because the detection of anomalous isoenzymes of CK in serum ma serve as a diagnostic marker or as an indicator of the effectiveness of treatment.