Characterization of the human B cell stimulatory factor 1 receptor

125I-labeled recombinant human B cell stimulatory factor 1 (BSF-1) was used to characterize receptors specific for this lymphokine on in vitro cell lines representing human B, T, and hematopoietic lineages, as well as on adherent cell lines of epithelial and endothelial origin, and on primary human gingival fibroblasts. BSF-1 binding was extremely rapid and saturable at both 4 and 37 degrees C, with a slow dissociation rate. On all human cell types examined, BSF-1 bound to a single class of high-affinity receptor (less than 3,000 receptors per cell) with a Ka of 0.5-1.0 X 10(10)/M. Human BSF-1 also bound to cell lines of simian but not murine origin. Comparison of kinetic characteristics obtained with a yeast-derived hyperglycosylated form of BSF-1 (Mr 60,000) and N-glycanase-treated, sugar-free BSF-1 (Mr 15,000) showed no significant differences. Among a panel of lymphokines and growth hormones, only unlabeled human BSF-1 was able to compete for the binding of 125I-labeled human BSF-1. Affinity crosslinking experiments resulted in the identification on both Raji cells and on primary human gingival fibroblasts of a receptor subunit with an average Mr of 139,000. These studies show that the BSF-1 receptor on human cells has an extremely broad cellular distribution, while further supporting the notion that the ability of BSF-1 to mediate a spectrum of biological activities cannot be accounted for by overt differences in the receptor for this lymphokine on different cell lineages.     

Induction and upregulation by interleukin 2 of high-affinity interleukin 2 receptors on thymocytes and T cells.

We show that purified recombinant interleukin 2 (rIL-2) alone induces the expression of high- and low-affinity interleukin 2 (IL-2) receptors in vitro on human T cells and thymocytes that have not been activated previously by lectins or other inducing agents. IL-2 receptors are expressed after 24 hr, as determined by the binding of 125I-labeled monoclonal anti-IL-2 receptor antibody 2A3, which binds equally to high- and low-affinity receptors. High-affinity receptors were distinguished from low-affinity receptors by the binding of 125I-labeled IL-2 to T cells and by the proliferative response of thymocytes to IL-2, in concentrations that selectively interact with the high-affinity class of IL-2 receptors. The IL-2-induced proliferation of thymocytes in vitro induced by IL-2 alone is dependent upon the concentration of IL-2 and is inhibited by monoclonal anti-Tac antibody, indicating that the proliferative response is mediated by the binding of IL-2 to the receptors. In addition, we demonstrate that IL-2 augments the number of high-affinity receptors on concanavalin A-activated thymocytes. These results document that IL-2 acts as a hormone that induces the activation of thymocytes and T cells, as evidenced by the de novo induction of biologically active, high-affinity IL-2 receptors. IL-2 also upregulates the expression of high-affinity IL-2 receptors on activated thymocytes. These observations illustrate the biologic importance of the regulatory role of IL-2 in the immune response.     

Creatine kinase BB in blood as index of prognosis and effect of treatment after severe head injury

Summary High concentrations of creatine kinase BB (CK-BB) were found in all blood samples drawn within 6 hours of accident from 45 patients with brain contusion. The highest concentrations of more than 100 microg/1 were measured in blood samples taken shortly after the accident from patients with a Glasgow Coma Score (GCS) of 6 or less.The CK-BB concentrations decreased rapidly to normal within 36 hours of accident in the patients given intensive care guided by intracranial pressure (ICP) monitoring. In patients with less severe injuries according to GCS the initial CK-BB concentrations were generally lower and normalized less rapidly. The outcome after 6 months was moderate or good in all 9 patients who had this rapid normalization of blood CK-BB. On the other hand, of 20 patients who had a more slow CK-BB decrease, only 9 had an acceptable outcome.Delayed ICP increase to more than 40 mm Hg and even delayed brain tamponade did not result in CK-BB levels higher than 5 microg/1. Brain tamponade in the acute stage resulted in rapid CK-BB decrease in the blood.In paired simultaneously drawn samples of lumbar cerebrospinal fluid (CSF) and blood, CK-BB levels were generally higher in the CSF.Hans-Kristian Nordby is a fellow of the Norwegian Research Council for Science and Humanities.     

Associations between central obestiy and indexes of hemostatic, carbohydrate and lipid metabolism. Results of a 1-year intervention from the Oslo Diet and Exercise Study

The relationships of central obesity and physical fitness to indexes of hemostatic, lipid and glucose metabolism both at baseline and after 1 year of diet and exercise intervention were examined in 209 sedentary middleaged men and women with increased coronary risk factor levels. Central obesity was measured as either waist circumference or waist/hip ratio. Maximal oxygen uptake was used as a measure of physical fitness. The cross-sectional results show that there were significant correlations between waist circumference and euglobuline clot lysis time (r=0.23), factor VII (r=0.16), glucose and insulin before and after 1 h glucose load (r ranging from 0.32 to 0.50). The 1-year intervention gave the following associations between changes in waist circumference and changes in: euglobuline clot lysis time (r=0.27), factor VII (r=O. 19), carbohydrate variables and lipids (IrI ranging from 0.19 to 0.43). Also the other indexes of obesity and physical fitness showed significant correlations to indexes of hemostatic, lipid and glucose variables, both cross-sectionally and for changes after the 1 -year intervention. The associations between changes in central obesity and changes in indexes of hemostatic, carbohydrate and lipids were generally stronger during 1 year of diet and exercise intervention than those found at baseline. Multiple regression analyses with waist circumference, waistlhip ratio, percent body fat and Vo_2max as independent variables and indexes of hemostatic, carbohydrate and lipid metabolism as dependent variables showed that waist circumference was a significant predictor for indexes of the hemostatic, carbohydrate and lipid metabolism, mostly independent of physical fitness. The cross-sectional and 1-year change results support each other and therefore underscore the importance of abdominal obesity as an important risk factor for cardiovascular disease.     

The diagnostic value of measuring creatine kinase BB activity in cerebrospinal fluid following acute head injury

Summary During a period of 2 months the activity of creatine kinase BB (CK-BB) was measured in the cerebrospinal fluid (CSF) from 93 consecutive patients admitted as emergencies to the Neurosurgical Department.Fourteen of the 15 patients with verified brain contusion showed an increased activity of CK-BB in the CSF whereas all patients with various other acute neurological disorders, such as epilepsy and acute headache, had a normal CK-BB activity. Two of 5 patients with subarachnoidal haemorrhage and 13 of 58 patients classified as concussion also showed an increased CK-BB activity. Spinal fluid pressure, number of red cells and activity of CK (total) were less useful than CK-BB in diagnosing acute brain damage. Even diagnostic ventricular puncture with a Fisher cannula, producing a tiny (diameter=2.8 mm) brain lesion, gave rise to an increased CK-BB activity.CSF sampled repeatedly from 10 other patients with brain contusion showed CK-BB activities that suggest the optimum period for sampling to be between one and 15 hours after head injury. The results obtained suggest that CK-BB is a reliable indicator of brain damage following head injury.Petter Urdal is a fellow of the Norwegian Research Council for Science and Humanities.     

The prognosis of patients with concussion and increased creatine kinase BB in the cerebrospinal fluid

Summary In a series of 93 emergency patients, 58 were classified as concussions on a clinical basis. Thirteen of the patients with concussion had increased levels of creatine kinase isoenzyme BB (CK-BB) in their cerebrospinal fluid (CSF). We performed a prospective, follow-up investigation comparing 10 patients with a CK-BB increase and 10 patients without a CK-BB increase after concussion.Within 24 hours, at 6 months and 3 years after concussion, each patient was subject to a special interview to obtain pre-concussional baseline data and post-concussional follow-up data concerning their complaints and capacity for daily activities. We found a definite change towards increasing disability in 8 of the 10 patients with a raised CK-BB, and in only 1 of the 10 patients with normal levels of CK-BB. A careful neuropsychological examination confirmed inferior performance in tests especially sensitive to brain injury in patients with a CK-BB increase.Our results suggest that increased levels of CK-BB after concussion signify a more severe injury which is not found in the clinical examination during the first days after the accident, and that these patients are a high-risk group for the development of post-concussional problems and symptoms.     

Rapid immunometric measurement of C-reactive protein in whole blood.

We examined an instrument-free test for C-reactive protein (CRP) in whole blood. The NycoCard CRP Whole Blood test uses a cell-solubilizing dilution liquid, a membrane-bound antibody that binds CRP, and a gold-conjugated antibody for making visible the bound CRP. We obtained essentially identical dose-response curves in citrate-, heparin-, and EDTA-treated blood. CVs were 6.7-12.5% within series and 10.1-14.7% between series. The detection limit was 12 mg/L. Intralipid added to blood increased measured CRP by 10-20%, whereas no change was seen with added bilirubin, added serum amyloid P component, or the presence of rheumatoid factor. In 234 patients' blood samples the results of the NycoCard Whole Blood test correlated well (r = 0.96) with those of a turbidimetric serum method. The test allows reliable measurement of CRP from a small volume of whole blood (25 microL) without using expensive equipment; it should be useful for decentralized testing in hospital departments, emergency units, and primary health care centers.     

Brown pigment stones in the common bile duct: reduced bilirubinate diconjugate in bile

BACKGROUND: Bilirubin is the main component of most common bile duct stones. Normally, almost all bilirubin in bile is conjugated to glucuronic acid or some other sugar moiety. These conjugates are unstable and liable to deconjugation. Unconjugated bilirubin is insoluble and may precipitate as the calcium salt found in brown pigment stones. The pattern of bilirubin conjugates in common duct bile of patients with choledocholithiasis has been unknown. METHODS: In a clinical series of 55 patients with choledocholithiasis common-duct bile was aspirated, and the bilirubin conjugates analyzed with high-performance liquid chromatography. One stone from each patient was analyzed for cholesterol and bilirubin content to determine stone type. RESULTS: Sixteen patients had cholesterol stones, 38 patients had brown pigment stones, and 1 patient had a black stone. Patients with pigment stones had a lower percentage of bilirubin diglucuronide (median, 60.3%; interquartile range, 49.7%-67.3%) than patients with cholesterol stones (64.0%; 60.2%-73.3%) (Mann-Whitney, P=0.015). No significant difference was found for the other bilirubin conjugates, total bilirubin, or biliary pH when pigment and cholesterol stone patients were compared. The time of bile sampling in relation to papillotomy and treatment of cholestasis was not associated with the low percentage of bilirubin diglucuronide. The observation of reduced values for bilirubin diglucuronide could not be ascribed to duodenal diverticula or Billroth-II gastric resection. CONCLUSION: The percentage of the main bilirubinate conjugate, bilirubin diglucuronide, is decreased in the common duct bile of patients with pigmented compared with cholesterol stones.     

Macro creatine kinase BB in serum, and some data on its prevalence.

We report the case of a patient with persistently above-normal activity of creatine kinase (CK) in serum, a major fraction of which on electrophoresis moved as a band between the MM and MB isoenzymes and on anion-exchange column chromatography eluted in the MB fraction. Measurements in the presence of specific M or B subunit-inhibitory antibodies indicated that 93% of the activity consisted of B-isomers. From these experiments we conclude that the abnormal CK is of BB nature. Gel filtration and immunoglobulin precipitation showed that the CK-BB was complexed with IgG. Normal CK-BB, when mixed with the patient's serum, was converted to macro CK-BB. In vitro stability of 37 degrees C of the abnormal enzyme was much greater than that of normal BB and MM isoenzymes. Following this finding, we then assessed 310 sera, received for enzyme assay by the clinical laboratory, for electrophoretically abnormally migrating CK isoenzymes. Of these, five (1.6%) contained such enzymes, all being of BB nature. They were of increased molecular mass, and at least three of them were complexed with IgG.