P861A quantitative CCTA evaluation in non-obstructive coronary artery disease for the diagnosis of vessel-specific ischemia: results from the prospective, multicenter, international CREDENCE trial

Aim

To improve the diagnosis of coronary vessel-specific ischemia in non-obstructive coronary artery disease (CAD) using a quantitative whole-heart coronary computed tomography angiography (CCTA) evaluation. To date, predictors of ischemia in non-obstructive CAD remain underexplored.

Methods

Within the CREDENCE trial, 612 patients with suspected CAD at 13 sites (64±10 years, 70% men) underwent coronary computed tomography angiography (CCTA) and invasive coronary angiography with 3-vessel fractional flow reserve (FFR) measurements. For this specific analysis, only vessels with non-obstructive plaque (1–49% maximal diameter stenosis) by CCTA were included. The primary endpoint was coronary vessel-specific ischemia which was defined as FFR ≤0.80 (or ≥90% stenosis). Multivariable logistic regression modeling was performed to evaluate the effect of quantitative CCTA features beyond coronary stenosis on the prevalence of vessel-specific ischemia.

Results

FFR ≤0.80 (or ≥90% stenosis) was prevalent in 22.8% of 1,102 vessels with non-obstructive plaque. Using a step-wise approach, in addition to diameter stenosis (χ2=72), non-calcified PAV (χ2=126, P<0.001), lumen volume (χ2=175, P<0.001) and number of lesions with >30% stenosis (χ2=187, P=0.001) were independent CCTA-predictors of coronary vessel-specific ischemia (Figure 1). In the final model, diameter stenosis was no longer significantly associated with ischemia (P=0.236).

Figure 1

Conclusion

In vessels with non-obstructive plaque on CCTA, ischemia was present in approximately 20%. Measures of overall non-calcified plaque burden and smaller lumen volume were more important determinants of vessel-specific ischemia than maximal diameter stenosis.

Acknowledgement/Funding

NIH R01-HLL118019; Dalio Foundation and Michael J. Wolk Foundation

4182Sex specific patterns in the onset and manifestation of coronary atherosclerotic plaque; insights from the multi-center CCTA CONFIRM registry

Background

Pathobiologic data support varied atherosclerotic plaque characteristics which uniquely define risk in women as compared to men (i.e., plaque erosion versus rupture). The advent of noninvasive coronary computed tomographic angiography (CCTA) allows for further exploration as to a sex-specific signature of atherosclerotic plaque features unique to women and different from that of men. In this analysis, we compared sex differences in the age of onset of coronary atherosclerosis and varied plaque findings between women and men.

Methods

From the multicenter CONFIRM registry, the Leiden CCTA score (based on segmental plaque extent, location, severity, and composition) was calculated in women and men without prior CAD, with imputation for missing plaque data. First, women and men were matched on the Leiden CCTA score to allow assessment of differences in atherosclerotic profile. Second, the earliest age of women and men to display a median Leiden CCTA score >0, >2, >6, >8 was evaluated. Third, the prognostic value of previously established thresholds of the Leiden CCTA score was examined for all-cause mortality with Cox-proportional hazard analysis, and specifically a sex interaction.

Results

In total, 11,678 women (age 58.5±12.4 years) and 13,272 men (age 55.6±12.5 years) were included. Of the patient subset matched on Leiden CCTA score (10,266 women, score 4.1±6.0 and 10,266 men, Leiden score 4.1±6.0, P=0.589), women were characterized by less obstructive CAD (≥50% stenosis) (17.5% vs 19.1%, P=0.003), more frequent non-obstructive left main plaque (10.1% vs 8.9%, P=0.004) and a lower number of segments with non-calcified or mixed plaque, but an equal number of calcified plaques. The earliest age when women and men have a median Leiden CCTA score above 0, 2, 4, 6, or 8 was consistently 14 to 16 years later for women. A visual representation of the CAD development delay is shown in Figure 1. Adjusted for age, the hazard ratio for death (827 events) for a score 6–20, and >20 (compared with 0–6) was 1.95 (95% CI 1.56–2.42), and 3.44 (95% CI 2.40–4.93) for women, respectively, and 1.63 (95% CI 1.31–2.03), 2.22 (95% CI 1.64–3.00) for men, respectively (P-interaction 0.006). Despite the low number of events, women <50 years with a score >20 were at 12.8 (95% CI 3.58–45.73) times increased risk.

Conclusion

There is an approximate 15-year delay in onset of coronary atherosclerosis for women compared to men. The burden of atherosclerotic plaque is associated with a higher relative hazard for death among women than men. The pattern of more nonobstructive CAD, especially in the left main coronary artery, but also less non-calcified plaque supports a sex-specific plaque signature which may uniquely define risk among women as compared to men.

Acknowledgement/Funding

The research reported in this manuscript was funded, in part, by the National Institute of Health (Bethesda, MD, USA) under award number R01 HL115150.

[Urinary symptoms and urodynamic findings in Parkinson's disease]

INTRODUCTION

Urinary symptoms in Parkinson's disease (PD) are minor but disabling. We have analyzed correlation of urinary symptoms with motor symptoms, duration and severity of PD and urodynamic abnormalities observed. Response to treatment with tolterodine was also assessed.

METHODS

PD male patients with a score in IPSS questionnaire over 7 and female patients with a score in IU-4 scale over 5 were included in the study. Intensity of neurological symptoms (UPDRS score), seriousness of PD (Hohen-Yahr stage), urodynamic parameters, and urinary sediment were analyzed in each patient. Abdominal ultrasonography and rectal examination were performed in males to exclude obstructive prostatic pathology. Patients without evidence of urinary flow obstruction were treated with tolterodine.

RESULTS

Three out of the 19 patients were excluded because of abnormal urinary sediment and the rest (n = 16) were included. Urinary symptoms correlated with rigidity severity (p < 0.01) and years of evolution of PD (p < 0.01). Rigidity (p < 0.01) was the neurological sign with the highest UPDRS motor scale score. Overactive bladder was present in 13 cases (81.2%) and 4 of them had urinary flow obstruction. Clinical improvement in nine patients treated with tolterodine was mild (33%).

CONCLUSIONS

Urinary symptoms correlate with rigidity severity and with years of evolution of PD. The use of both the urinary questionnaire and urodynamic study allow us to identify the type of bladder dysfunction and select the patients who would benefit the most from anticholinergics. Tolterodine reduced miccional urgency and frequency in PD, but was ineffective on urinary incontinence.

Mutations in HIV-1 Reverse Transcriptase during Therapy with Abacavir, Lamivudine and Zidovudine in HIV-1-Infected Adults with No Prior Antiretroviral Therapy

Objective

To evaluate HIV-1 reverse transcriptase (RT) drug resistance in patients receiving abacavir, lamivudine and zidovudine therapy.

Methods

In a randomized, double-blind study, 173 anti-retroviral treatment-naive HIV-1-infected adults received abacavir/lamivudine/zidovudine or lamivudine/zidovudine for up to 48 weeks. After week 16, patients could switch to open-label abacavir/lamivudine/zidovudine, and those with plasma HIV-1 RNA (vRNA) >400 copies/ml could add other antiretrovirals. From weeks 16 to 48, samples with vRNA >400 copies/ml were collected for genotyping and phenotyping.

Results

At baseline, 90% of isolates were wild-type (WT). At week 16, vRNA was >400 copies/ml in seven of 72 (10%) patients receiving abacavir/lamivudine/zidovudine and in 41 of 66 (62%) receiving lamivudine/ zidovudine. At week 16, the genotypes in isolates from the abacavir/lamivudine/zidovudine group were M184V alone ( n=3 cases), WT ( n=3) and M184V plus thymidine analogue mutations (TAMs) ( n=1). The genotypes in isolates from the lamivudine/zidovudine group were M184V alone ( n=37), WT ( n=1) and M184V plus TAMs ( n=3). In the four cases where M184V plus TAMs were detected some mutations were present at baseline. Despite detectable M184V in 74% of patients on lamivudine/zidovudine, addition of abacavir with or without another antiretroviral therapy resulted in a reduction in vRNA, with 42 of 65 (65%) patients having week 48 vRNA <400 copies/ml (intent-to-treat with missing=failure). At week 48, the most common genotype was M184V alone in the abacavir/ lamivudine/zidovudine group (median vRNA 1–2 log10 below baseline), and M184V with or without TAMs in patients originally assigned to lamivudine/zidovudine. At week 48, phenotypic results were obtained for 11 isolates for patients from both arms, and all had reduced susceptibility to lamivudine but all remained sensitive to stavudine, all protease inhibitors and all non-nucleoside reverse transcriptase inhibitors. Three, three and two isolates had reduced susceptibility to abacavir, didanosine and zidovudine, respectively.

Conclusions

Abacavir retained efficacy against isolates with the M184V genotype alone. TAMs did not develop during 48 weeks of abacavir/lamivudine/zidovudine therapy and were uncommon when abacavir was added after 16 weeks of lamivudine/zidovudine therapy. Limited mutations upon rebound on this triple nucleoside combination allows for several subsequent treatment options.

Design and tolerance analysis of a router with an amplified resonator and Bragg gratings

A novel ring resonator configuration with Bragg gratings is presented. The stability of this configuration is studied by a z-transform technique. A router design with a FWHM of 17 MHz, a -40-dB rejection ratio, and a 15-dB gain at the output port is reported. The influence of temperature and of fabrication tolerance on parameters of this router configuration implemented with fiber technology is reviewed. Deviations in design specification owing to parameter variations are studied and compensated for with a gain control of 2.4% in a specific design.

Determination of total and specific IgE using UNICAP 100: comparative study with the CAP system

The methods of serum determination of specific IgE to different allergens have showed lower diagnostic sensitivity than the alternative in vivo methods, the skin tests. The CAP system from Pharmacia, owing to its solid phase, has ameliorated this disadvantage, showing in various studies greater diagnostic sensitivity than the classic RAST, without affecting specificity. However, this system is still semi-automatic and requires daily calibration. UNICAP 100 is a completely automatic autoanalyser for total IgE, specific IgE and Eosinophil Cationic Protein, which combines the high sensitivity of the CAP system with complete automation and monthly calibration. The aim of the present study is to assess the practicality and reliability of UNICAP 100, when compared to the CAP System, for the determination of total IgE and specific IgE, as well as the sensitivity and diagnostic specificity; using as a reference skin tests in 150 paediatric patients. The coefficients of variation in the study of intraseries imprecision ranged between 2.1% and 3.6% for total IgE and between 2.2% and 5.1% for specific IgE, depending on the allergen and the level studied. The intraseries imprecision ranged between 3.3% and 7.7% for total IgE and between 5.2% and 8.9% for specific IgE. The coefficients of correlation of the study of interchangeability with the results of the CAP System varied between 0.985 and 0.998, all the allergens tested (9) being interchangeable. Finally, the diagnostic sensitivity varied between 70% and 95% and the specificity between 87% and 100%. In conclusion, UNICAP 100 showed results that were interchangeable with the CAP System, noticeably improving the benefits owing to its complete automation and its calibration system.

Evolution of salmonella aortitis towards the formation of abdominal aneurysm

We present a case of salmonella aortitis with necrosis of the arterial wall and its evolution to the formation of an abdominal aneurysm over a 6-day period. Computed tomography was performed before and after the development of a mycotic aneurysm. Presurgical aortography was also performed. The findings obtained give a dynamic concept to this pathology and show its rapid evolution in a short period of time.

Cutaneous lymphangiectases associated with severe photoaging and topical corticosteroid application

We report an elderly patient with lymphangiectases arising within skin affected by photoaging, steroid atrophy, and inflammation. Bullous lesions appeared in several sites following a year of topical corticosteroid applications for neurodermatitis. Light and electron microscopy showed that the bullae consisted of dilated lymphatic vessels within the dermis. There was also marked nodular elastosis and attenuation of dermal collagen. We suggest that this patient's lymphangiectases resulted from abnormal structure and function of the dermis due to photoaging and steroid atrophy.

Effect of conditions in obtaining blood samples for ECP testing in children

Eosinophil Cationic Protein (ECP) is a basic protein found in eosinophil granules. This cell and its mediators are currently considered to be potential indicators of the severity of inflammation in the organism. ECP concentration can be reliably tested using several RIA or ELISA methods. It is well known that the conditions of sample obtention can affect the ECP values in blood. The aim of this study is to establish which parameters affect ECP testing during regular blood sample collection and how they affect it. Blood samples taken for the routine study of five children attended in our department were analysed: four were asthmatic and one child had atopic dermatitis. In the results we observed that ECP was not detected in the blood samples taken with EDTA tripotassium. In both the plasma samples taken with heparin as well as with serum, more ECP was released at a higher temperature. In the release of ECP obtained by coagulation, samples at 37 degrees showed values of between 4 and 20 higher than those obtained for an hour at 0 degrees. There is a considerable variability in the testing of ECP depending on the blood test extraction conditions, the range is bigger in the samples with eosinophils. These results imply the need to define a stricter protocol for obtaining samples than that suggested at present.

Specific IgE determination using the CAP system: comparative evaluation with RAST

The CAP system's main contribution is its solid phase, which consists of a cellulose polymer activated within a capsule (the ImmunoCAP). This solid phase can bind more protein to it, and, in addition, the conditions of reaction seem to make the system more sensitive at detecting antibodies to certain antigens. It is therefore important to assess the new analytical and diagnostic performance in comparison with previous systems. In this context, we studied the reliability and comparison with the RAST and with skin tests carried out on 144 pediatric patients. Skin tests and specific IgE for radioimmunological RAST (radio-allergosorbent test) and for the fluoroimmunological CAP system were performed on all the patients. The RAST/CAP correlation quotients for the different allergens tested varied between 0.971 and 0.991. Diagnostic sensitivity increased for all the allergens studied and specificity remained unchanged. The system provides reliable results, with better diagnostic capacity than RAST, but it must be quantified for each allergen because its results are not interchangeable.

Visible persistence decay rates for schizophrenics and substance abusers

Information-processing deficits are consistently reported for schizophrenics. The findings from the majority of psychophysical tasks indicate that the deficit is specific to schizophrenics and thus may represent a marker for schizophrenia. The present study evaluated for specificity of impairment by including controls using methadone. A two-pulsed forced choice information-processing task that required the detection of a line or a blank-field during an interstimulus interval (ISI) indexed efficiency of processing (i.e., visible persistence). There were 19 schizophrenic, 9 schizoaffective, 8 depressed, 12 on methadone, and 12 normal subjects. The visual stimuli were low and high spatial frequency gratings. Either a line of equivalent width to those of the gratings or a blank field was presented during the ISI. The gratings were presented for 150 msec prior to and following an ISI of 30, 60, 90, 120, 150, and 350 msec. The results support previous findings for impaired processing during a 90-150 msec interval for schizophrenics. Also, the methadone-using controls were not significantly different from schizophrenics. Normal and depressed controls' profiles did not differ from each other, however, they were significantly different from the other groups. The results support an early information-processing deficit in schizophrenic individuals and may implicate dysregulation of dopaminergic neuromodulation.

Outcome of psychoeducation for HIV risk reduction

Our objectives were to assess the effects of a psychoeducational (PE) program designed to reduce HIV risk behaviors in recovering drug abusers and to evaluate mediating variables associated with risk reduction as described by the AIDS Risk Reduction Model (ARRM). Consecutive admissions to a Department of Veterans Affairs drug dependence inpatient treatment program (n = 152) were randomly assigned to PE or a standard information (INFO) condition. PE involved a 6-hour small group intervention designed to enhance knowledge and attitudes regarding HIV prevention, improve skills in condom use and needle sterilization, and modify high-risk sex- and drug-related behaviors. The INFO condition involved presentation of audiovisual and printed HIV prevention material with similar content. Following intervention, PE subjects showed significantly enhanced self-efficacy, condom use skills, and sexual communication skills relative to the INFO group. At 3-month follow-up, the PE group showed significantly greater reductions on some measures of sexual HIV risk behaviors relative to the INFO group. Hypotheses derived from the ARRM regarding presumed relationships between positive changes in mediating variables (e.g., self-efficacy and sexual communication) and ultimate outcome variables (e.g., condom use) were supported.

Psychosocial factors associated with condom use among African-American drug abusers in treatment

Although strategies for decreasing injection drug use have met with moderate success, efforts to decrease high-risk sexual behaviors have been less successful. Because condom use reduces HIV transmission, it is critically important to identify the attitudinal, emotional, and behavioral factors associated with using condoms. This study evaluated the relationship between condom use and various psychological and behavioral variables among heterosexual, African-American, cocaine-dependent men within the context of the AIDS Risk Reduction Model (ARRM). Subjects who used condoms (n = 52) reported significantly higher levels of self-efficacy, condom use skills, and sexual communication with partners than non-users (n = 84). However, the groups did not differ in perceived susceptibility, anxiety concerning HIV transmission, response efficacy, or knowledge regarding HIV. These findings suggest that future interventions focus on enhancing self-efficacy and condom use skills, as well as eroticizing condom use.

Specific IgE antibodies in nasal secretions: correlation with serum values and clinical tests

The presence of specific IgE in external secretions and the possibility of quantifying it has aroused the interest of many research workers. Nevertheless, there is still disagreement with regard to how useful this practice is from a clinical point of view. We have compared the presence of Dermatophagoides pteronyssinus (Dp) specific-IgE in the nasal secretion of 17 patients suffering from rhinitis with the results of prick tests and nasal and/or conjunctival challenge tests. As a preliminary step we have updated techniques and made a correlation between the parameters mentioned. The results for total IgE (n = 17) show a correlation coefficient (r = .39, NS) between serum values (251 +/- 239) U/L and those obtained in nasal secretion (28 +/- 36) U/L. (2) Serum and nasal-Dp-specific-IgE values (13 +/- 15 and 5 +/- 9, respectively: (r = .72, P = .0011) match in 14 of the 17 determinations. In two of them, the serum values of Dp-specific-IgE, but not the nasal ones, match the in vivo tests. In the others, it is the nasal secretion determination that matches the in vivo tests while the serum and nasal determinations match (82%). These results match in 86% of cases with prick tests and in 93% with nasal/conjunctival challenge tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Deficits in initial feature registration of schizophrenics and substance abusers

Information processing deficits are consistently reported for schizophrenics. The present study evaluated if the longer duration required by schizophrenics to visually recognize a target may qualify, as proposed by previous studies, as a vulnerability and/or trait biological marker. Critical stimulus duration (CSD) was used as the index of initial target registration and recognition. The CSD is the minimal duration, in ms, to meet task criterion, which in the present study was seven consecutive identifications of the target letter 'T' or 'A'. There were 13 normal controls, 11 methadone maintenance experimental controls, 21 chronic schizophrenics and 12 subacute schizophrenics. Analysis of variance revealed that the CSDs of normal controls and subacute schizophrenics were not statistically different (p > 0.05); the CSDs of chronic schizophrenics were not statistically different from methadone controls (p > 0.05), while the chronic schizophrenics and the methadone controls' CSDs were statistically different from the normal controls and the subacute schizophrenics. The results support earlier reports of long target duration required by chronic schizophrenics for feature recognition. Since retarded CSDs were obtained for methadone control but not for acute schizophrenics, the CSD does not qualify as a specificity or a vulnerability index for schizophrenia. A neurophysiological explanation is proposed for the findings.

Cocaine and speedball users: differences in psychopathology

Affective distress and related symptoms associated with co-injected cocaine and opioid ("speedball") use are incompletely explored, and the extent to which they diverge from problems shown by cocaine abusers who do not prefer opioids is unknown. This investigation compared groups of speedball and non-speedball cocaine users on global measures of depression and anxiety and modal groupings of personality characteristics measured by the MMPI. Compared to men who use cocaine without opioids, compulsive speedball users evidenced significantly greater problems with depression, trait anxiety, and related symptomatology, and were more uniformly characterized by modal profiles reflecting severe psychopathology and maladjustment. These results agree with descriptions of severe pathology associated with speedball use.

Reagent strip for semiquantitative total and specific IgE measurement: a comparison to radioisotopic methods

Determination of total and specific IgE using reactive test strips may afford a useful screening method in the in vitro diagnosis of allergens owing to easy use and possible correlation with established methods. T.D. LETI reactive strips for the semiquantitative determination of total IgE is a method combining classical fundamentals (sandwich anti-IgE-IgE-labeled anti-IgE) and the use of strip methods. It also permits determination of specific IgE levels in a wide range of Mediterranean and food (10) allergens. In a preliminary assessment, this method was correlated with isotopic PRIST for total IgE and with Phadebas RAST for specific IgE. The most important features are: a) no additional equipment besides serum or whole blood; b) cheaper and faster than PRIST for total IgE; c) correlation coefficient of 0.88 in the proposed range (n = 20) and 0.91 (n = 25) in the 10-500 U/ml range for PRIST/T.D. LETI for total IgE; d) specific IgE determination strips present sensitivity and specificity of 88 and 91%, respectively, in 180 allergens assayed in relation to Phadebas RAST. In conclusion, the in vitro diagnosis of allergens using reactive strips is currently a practical and simple method. By optimizing the top of the scale for total IgE and reducing the volume and/or time in specific IgE, it may prove to be an important screening method.

Semiquantitative determination of serum IgE by reagent strips: PRIST/TOTALE correlation

Due to its great simplicity, the determination of total and specific IgE with a reagent strip could be a screening method for in vitro allergy diagnosis if a correlation with classical techniques is verified. The TOTALE reagent strip for semiquantitative determination of total serum IgE is one of these methods and unites the now classical foundation (anti-IgE/IgE/anti-IgE labeled sandwich) and the ease of the reagent strip technique. In a preliminary evaluation of these methods we compared the PRIST isotopic method to the TOTALE one for serum total IgE. In summary, the most relevant consequences from this comparison are the following ones: a) The initial sample is the same for both: serum. b) No additional equipment or materials other than the serum sample are needed for TOTALE practising. c) The reagent strip has a lower cost and is faster than the PRIST method. d) Correlation coefficients were 0.89 (n = 35) in the range of measurement under study and 0.93 (n = 23) in the range from 5 to 200 U/L.

Phosphorylation of fibrinogen by casein kinase 2

Casein kinase 2 from rat liver cytosol phosphorylated human fibrinogen in a reaction that was not stimulated by Ca2+ or cyclic AMP, but was markedly inhibited by heparin, and proceeded at a similar rate when either ATP or GTP was used as phosphate donor. Analysis of casein kinase 2 by glycerol-density-gradient centrifugation showed that the activities towards fibrinogen, casein, phosvitin, high-mobility-group protein 14 and glycogen synthase coincided. Maximal incorporation into fibrinogen by casein kinase 2 averaged 1 mol of phosphate/mol of protein substrate, most of it in the alpha-chain, although some phosphorylation of the beta-chain was also detected. Analysis of phosphorylated alpha-chain revealed that most of the phosphate was incorporated on serine. Phosphorylation of human fibrinogen was also performed by casein kinase 2 from human polymorphonuclear leucocytes, lymphocytes and platelets.

Intralipid and free plasmatic tryptophan in vitro

In an attempt to investigate the role of the lipidic emulsion Intralipid in the development of metabolic encephalopathy in a patient showing high free tryptophan levels, the relationship between lipidic emulsion and free tryptophan was examined in in vitro experiments. The addition of intralipid to normal serum produces an immediate increase in non-esterified fatty acids and a parallel rise in free tryptophan. Moreover, when serum with intralipid is incubated at 37 degrees C, the lipases release new non-esterified fatty acids and the free tryptophan increases proportionally. The non-esterified fatty acid content of intralipid was found to be 12 +/- 2 mEq X 1(-1). An inverse correlation was seen between free tryptophan and different serum albumin concentrations. It is concluded that intralipid causes an increase in free tryptophan levels. It is known that in vivo free tryptophan modulates 5-hydroxytryptamine synthesis and thus may be considered a possible causal agent for encephalopathy.

Cyclic adenosine 3':5'-monophosphate-dependent and -independent protein kinases in human leukemic cells

The pattern of protein kinase activity in leukemic cells from patients with chronic myelocytic leukemia, acute myeloblastic leukemia, acute monocytic leukemia, chronic lymphocytic leukemia, and acute lymphoblastic leukemia was studied and compared with normal peripheral blood granulocytes and lymphocytes. Our data showed that: (a) histone kinase activity was slightly lower in leukemic cells than in normal cells, whereas casein kinase activity was 2- to 3-fold higher in leukemic cells; (b) cyclic adenosine 3':5'-monophosphate stimulated 1.4- to 1.6-fold histone kinase activity of both normal and leukemic cells, whereas it did not stimulate casein kinase activity; (c) the ratio of histone kinase activities to casein kinase activities correlated directly with the maturation of the white blood cells; and (d) histone and casein kinase activities of extracts from normal and leukemic cells behaved similarly on chromatography on phosphocellulose and casein/Sepharose 4B. These results suggest that the increase in casein kinase activity is not due to the appearance of a new type of casein kinase but to an increase of the casein kinases 1 and 2 present in normal cells.

Purification and characterization of two cyclic AMP-independent casein/glycogen synthase kinases from rat liver cytosol

Two cyclic AMP-independent protein kinases (ATP: protein phosphotransferase, EC 2.7.1.37) (casein kinase 1 and 2) have been purified from rat liver cytosol by a method involving chromatography on phosphocellulose and casein-Sepharose 4B. Both kinases were essentially free of endogeneous protein substrates and capable of phosphorylating casein, phosvitin and I-form glycogen synthase, but were inactive on histone IIA, protamine and phosphorylase b. They were neither stimulated by cyclic AMP, Ca2+ and calmodulin, nor inhibited by the cyclic AMP-dependent protein kinase inhibitor protein. The casein and glycogen synthase kinase activities of each enzyme decreased at the same rate when incubated at 50 degrees C. Casein kinase 1 and casein kinase 2 showed differences in molecular weight, sensitivity to KCl, Km for casein and phosvitin and Ka for Mg2+, whereas their Km values for ATP and I-form glycogen synthase were similar. The phosphorylation of glycogen synthase by these kinases correlated with a decrease in the +/- glucose 6-phosphate activity ratio (independence ratio). However, casein kinase 1 catalyzed the incorporation of about 3.6 mol of 32P/85000 dalton subunit, decreasing the independence ratio from 83 to about 15, whereas the phosphorylation achieved by casein kinase 2 was only about 1.9 mol of 32P/850000 dalton subunit, decreasing the independence ratio to about 23. The independence ratio decrease was prevented by the presence of casein but was unaffected by phosphorylase b. These data indicate that casein/glycogen synthase kinases 1 and 2 are different from cyclic AMP-dependent protein kinase and phosphorylase kinase.

Cyclic AMP-independent casein/glycogen synthase kinases from pig polymorphonuclear leucocytes

1. Two cyclic AMP-independent casein/glycogen synthase kinases were purified from pig polymorphonuclear leucocytes by chromatography on phosphocellulose followed by affinity chromatography on casein-Sepharose 4B or gel filtration on Bio-Gel A-1.5m. When the affinity step was used, the specific activities were 86 and 43units/mg of protein for casein kinase 1 and 2, respectively, whereas these values were 94 and 90units/mg of protein when the gel-filtration step was used. 2. These kinases differ as follows: (a) the molecular weight of casein kinase 1 (38000) is very much lower than that of casein kinase 2 (185000); (b) the K(m) for casein (0.46mg/ml) and K(a) for Mg(2+) (0.3mm) of casein kinase 1 are lower than those of casein kinase 2 (0.90mg/ml and 1.7mm respectively); (c) KCl stimulates the phosphorylation of casein by casein kinase 1, whereas it inhibits phosvitin phosphorylation by this enzyme; on the contrary, the effect of KCl on casein kinase 2 is very similar with either casein or phosvitin as substrate; (d) although both kinases phosphorylate rabbit muscle glycogen synthase I, the ratio of glycogen synthase to casein phosphorylation by casein kinase 1 is about 4-fold greater than that by casein kinase 2. Furthermore, (32)P incorporation into glycogen synthase promoted by casein kinase 1 (3.6mol of (32)P/mol of 85000-dalton subunit) is twice that observed with casein kinase 2 (1.8mol of (32)P/mol of 85000-dalton subunit). Such a phosphorylation results in a decrease in the glucose 6-phosphate-independence ratio of glycogen synthase to 10-15 with casein kinase 1 and to 35-45 with casein kinase 2. 3. The activity of both kinases is neither stimulated by cyclic AMP, Ca(2+) and calmodulin nor inhibited by cyclic AMP-dependent protein kinase inhibitor protein. 4. No phosphorylation kinase activity was observed with casein kinase 1 and 2 at either pH6.8 or 8.2 in the presence of Ca(2+). 5. Activities of both kinases on casein and glycogen synthase decreased in parallel when incubated at 50 degrees C.