A Risk Score Derived from the Analysis of a Cluster of 27 Serum Inflammatory Cytokines to Predict Long Term Outcome in Patients with Acute Myocardial Infarction: a Pilot Study.

BACKGROUND: The aim of our study was to evaluate the clinical utility and prognostic significance of a cluster of 27 serum cytokines for risk stratification after myocardial infarction. MATERIALS AND METHODS: We enrolled 33 consecutive patients admitted to our institution for acute myocardial infarction and prospectively followed. We evaluated traditional cardiovascular risk factors and assayed, during the acute phase, 27 serum cytokines (IL-1, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL -7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, EOTAXIN, FGF, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, MIP-1ß, PDGF, RANTES, TNF-α, VEGF) potentially associated with cardiovascular risk. Patients were divided into two groups during follow-up according to the occurrence or absence of adverse cardiovascular events (recurrence of angina, re-infarction, death, need of new revascularization, occurrence of heart failure). We developed an additive risk score by assigning one point for each cytokine that had a value greater than the median value (range 0-27). Cytokines alone and the cytokines score were related to cardiovascular events. RESULTS: Patients with and without major adverse cardiovascular events (MACEs) at follow up had a homogenous distribution of the main cardiovascular risk factors; differences were detected only for sex and age. Patients who experienced MACE had a significantly different distribution of I troponin (p=0.036), IL-8 (p=0.006), IL-13 (p=0.06), IL-10 (p=0.02), IL-17 (p=0.015), IP-10 (p=0.02), MIP-1ß (p=0.05). At univariate analysis, IL -8 (p=0.046 OR 1.13), IL-10 (p=0.05 OR 1.14) and MIP-1ß (p=0.016, OR 1.02) were significantly associated with the occurrence of MACE. This association was not confirmed at multivariate analysis. At the analysis of variance, a higher score was significantly associated with the occurrence of adverse events at follow up (F=5.07, p=0.03). At ROC curve analysis, a score greater than 13 better predicted the occurrence of adverse events at follow-up (AUC 0.72, p=0.03, sensibility 59.1%, specificity 81.8%). CONCLUSIONS: In our study we did not identify a single inflammatory cytokine able to predict adverse events in a long term follow up, whereas the presence of more than 13 cytokines above the median value was useful for risk stratification.

Early subclinical ventricular dysfunction in patients with insulin resistance.

AIMS: The aim of our study was to evaluate the relationship between insulin resistance and the detection of precocious echocardiographic signs of heart failure in patients with cardiovascular risk factors. METHODS: We enrolled 34 consecutive patients with cardiovascular risk factors. All patients underwent coronary angiography, echocardiography, and laboratory tests. Exclusion criteria were diabetes (fasting glucose greater than 126 mg/dl or treatment with insulin or oral hypoglycemic agents), coronary artery disease, creatinine above 1.5 mg/dl, left-ventricular hypertrophy, valvular heart disease, ejection fraction below 50%, atrial fibrillation, or other severe arrhythmia. The presence of insulin resistance was assessed by using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Ventricular function was investigated by echocardiography. RESULTS: Distinguishing patients with insulin resistance, based on the median value of HOMA-IR (<4.06 and >4.06), we observed that in the group with higher levels of HOMA-IR, there were echocardiographic signs of subclinical ventricular dysfunction statistically more frequent (E/A in group with HOMA <4.06: 1.159 + 0.33 vs. group with HOMA >4.06: 0.87 + 0.29, P = 0.0136; E/E': 6.42 + 4 vs. 15.52 + 3.26, P = 0.001; Tei index: 0.393 + 0.088 vs. 0.489 + 0.079, P = 0.0029; S wave: 0112 + 0.015 vs. 0.114 + 0.027, P = 0.0001; ejection fraction 59.11 + 4.75 vs. 58.88 + 6.81, P = 0.9078). Grade II diastolic dysfunction was observed in 5 patients, grade I in 12 patients, and 17 patients had normal diastolic function. On multivariate analysis, HOMA-IR (P = 0.0092), hypertension (P = 0.0287), waist circumference (P = 0.0009), high-density lipoprotein (P = 0.0004), and fasting blood glucose (P = 0.0003) were variables independently associated with diastolic dysfunction. On analysis of covariance, we found that the variables that influence diastolic dysfunction are HOMA-IR, waist circumference, BMI, and age, and that the only variable that influences Tei index is HOMA-IR. CONCLUSION: Insulin resistance is frequently associated with subclinical left-ventricular dysfunction. Patients with cardiovascular risk factors and increased HOMA-IR levels, although without diabetes mellitus, overt coronary artery disease, or hypertensive cardiomyopathy, may represent a target population for screening programs, recommended changes in lifestyle, and possibly the use of pharmacological interventions to prevent the onset of heart failure.

Biochemical analysis of TEM-134, a new TEM-type extended-spectrum beta-lactamase variant produced in a Citrobacter koseri clinical isolate from an Italian hospital.

OBJECTIVES: Kinetic characterization of TEM-134, a new TEM-type extended-spectrum beta-lactamase variant isolated from Citrobacter koseri during an Italian nationwide survey. TEM-134 is a natural derivative of TEM-2 with the following substitutions: E104K, R164H and G238S. METHODS: Recombinant TEM-134 was purified from Escherichia coli HB101 (pMGP-134) by three chromatographic steps (cation-exchange chromatography, gel permeation and fast chromatofocusing). Steady-state kinetic parameters (K(m) and k(cat)) were determined by measuring substrate hydrolysis under initial rate conditions using the Hanes linearization of the Michaelis-Menten equation. Modelling was carried out using the software Modeller (version 9.1). RESULTS: TEM-134 hydrolysed with variable efficiency (k(cat)/K(m) ranging from 5 x 10(3) to 8.0 x 10(5) M(-1) . s(-1)) penicillins, narrow-spectrum cephalosporins, cefepime, cefotaxime, ceftazidime and aztreonam, which appeared to be the best substrate. Molecular modelling of the enzyme indicated that the R164H substitution may result in a compromised omega loop in TEM-134 and this may be responsible for its narrower spectrum of activity. CONCLUSIONS: Kinetic data and molecular modelling suggested that R164H has a mild detrimental effect on the global activity of the enzyme.

Novel TEM-type extended-spectrum beta-lactamase, TEM-134, in a Citrobacter koseri clinical isolate.

A new natural TEM derivative with extended-spectrum beta-lactamase activity, TEM-134, was identified in a ceftazidime-resistant clinical isolate of Citrobacter koseri. Compared to TEM-1, TEM-134 contains the following mutations: Q39K, E104K, R164H, and G238S. The bla(TEM-134) gene was not transferable by conjugation and, apparently, was chromosomally encoded. Expression studies with Escherichia coli revealed efficient cefotaximase and ceftazidimase activity for TEM-134.