Influenza A(H1N1) viruses of the 1977/78 outbreak: isolation and haemagglutination properties.

During the H1N1 outbreak of 1977/8, the virus was isolated in embryonated eggs from 59 out of 76 patients (78%) with the serologically confirmed infection. A similar isolation frequency has been achieved during a period of six H3N2 outbreaks since 1972/3. The H1N1 strains were isolated less frequently from late specimens (collected 4--6 days from the onset of illness) and more often only in the second passage compared with the H3N2 viruses. The new H1N1 strains resembled those prevalent in the 1950s with respect to their ability to agglutinate erythrocytes of certain laboratory animals and to be eluted from these, and thus differed from the H3N2 viruses.     

Liver echogenicity: relation to systemic blood pressure and other components of the metabolic syndrome

We studied the impact of liver echogenicity among other potential predictors of systemic blood pressure (BP) and the metabolic syndrome. 38 persons (32 males, six females, aged 29 to 66) had their liver echogenicities scored, BPs measured and standard serum laboratory tests studied. There was a significant correlation between both systolic (r=0.438, p=0.006) and diastolic (r=0.498, p=0.001) BP and liver echogenicity. Liver echogenicity was the strongest predictor for systolic BP and the second strongest (after body mass index, BMI) for diastolic BP. Body height may modify the relation between liver echogenicity and systolic BP. Liver echogenicity also correlated significantly with BMI (r=0.527, p=0.001), serum triglycerides (r=0.472, p=0.003) and, to a lesser degree, with serum total cholesterol (r=0.305, p=0.066). Incidentally found increased liver echogenicity should alert the US performer and the clinician reading the report on the possibility of elevated BP or other features of the metabolic syndrome.     

Virtual screening of novel CB2 ligands using a comparative model of the human cannabinoid CB2 receptor

To identify novel selective CB2 lead compounds, a comparative model of the CB2 receptor was constructed using the high-resolution bovine rhodopsin X-ray structure as a template. The CB2 model was utilized both in building the database queries and in filtering the hit compounds by a docking and scoring method. In G-protein activation assays, 1-isoquinolyl[3-(trifluoromethyl)phenyl]methanone (40, NRB 04079) was found to act as a selective agonist at the human CB2 receptor.     

The gene for polycomb group protein enhancer of zeste homolog 2 (EZH2) is amplified in late-stage prostate cancer

Overexpression of the polycomb group protein enhancer of zeste homologue 2 (EZH2) has been found in several malignancies, including prostate cancer, with an aggressive phenotype. Amplification of the gene has previously been demonstrated in several malignancies, but not in prostate cancer. Our goal was to evaluate the gene copy number and expression alterations of EZH2 in prostate cancer. The copy number of EZH2 in cell lines (LNCaP, DU145, PC‐3, 22Rv1), xenografts (n = 10), and clinical tumors (n = 191) was studied with fluorescence in situ hybridization. All cell lines had a gain of EZH2. Eight of the ten xenografts showed an increased copy number of the gene, including one case of high‐level amplification (≥5 copies of the gene and EZH2/centromere ratio ≥2). 34/125 (27%) of untreated prostate carcinomas showed increased copy number, but only one case of low‐level amplification (≥5 copies of the gene and EZH2/centromere ratio <2), whereas half (25/46) of the hormone‐refractory carcinomas showed increased copy number, including seven cases of low‐level amplification and three cases of high‐level amplification (P < 0.0001). Expression of EZH2 was significantly (P = 0.0009) higher in hormone‐refractory prostate cancer compared with that in benign prostatic hyperplasia or untreated cancer, according to quantitative real‐time RT‐PCR assay. Also, the expression of EZH2 protein was found to be higher in hormone‐refractory tumors than in hormone‐naïve tumors by immunohistochemistry. The EZH2 gene amplification was significantly (P < 0.05) associated with increased EZH2 protein expression. The data show that amplification of the EZH2 gene is rare in early prostate cancer, whereas a fraction of late‐stage tumors contains the gene amplification leading to the overexpression of the gene, thus indicating the importance of EZH2 in the progression of prostate cancer. © 2006 Wiley‐Liss, Inc.     

Usefulness of T-wave loop and QRS complex loop to predict mortality after acute myocardial infarction

The aim of the study was to assess whether parameters based on the T-wave loop and QRS loop predict mortality, and cardiac mortality in particular, during follow-up of consecutive survivors of acute myocardial infarction (AMI). Patients with AMI (n = 437), treated according to contemporary guidelines, underwent digital high-resolution electrocardiography in orthogonal Frank leads (X, Y, Z) 5 to 14 days after AMI. Several T-wave and QRS loop parameters, such as the width and height of the loops and their ratio, T-wave loop dispersion (TWLD), QRS loop dispersion, and co-sine of the angle between the main vectors of the T-wave and QRS loops (TCRT), were calculated using a custom-made software package. During an average follow-up period of 43 +/- 14 months, 53 patients (12%) died. Of these 53 deaths, 35 were cardiac. TWLD and TCRT were the T-wave loop/QRS loop parameters that best predicted for cardiac mortality on univariate comparison (35.4 +/- 5.62 vs 32.8 +/- 2.87 for TWLD, p < 0.001 and -0.135 +/- 0.665 vs -0.657 +/- 0.518 for TCRT, p < 0.001, alive vs cardiac death, respectively). After adjustment for clinical risk markers in the Cox regression analysis, TWLD still significantly predicted for cardiac mortality (p < 0.05); however, TCRT had lost its predictive power. TWLD did not have significant univariate or multivariate association with noncardiac mortality. In conclusion, TWLD that describes the shape of the T-wave loop is a specific predictor of cardiac death and independent of the clinical risk markers in the current treatment era of patients with AMI.     

Differences in the activation patterns between sustained and self-terminating episodes of human ventricular fibrillation

BACKGROUND. Experimental studies have suggested that R-R interval dynamics during ventricular fibrillation (VF) have organized features, but whether dynamic behavior of non-sustained VF differs from sustained VF is unknown. AIM. The purpose of this study was to investigate whether the dynamics of R-R intervals during non-sustained VF differs from the dynamics during sustained VF. METHODS. A group of 67 patients undergoing routine implantable cardioverter defibrillator (ICD) testing was studied. Forty-three VF events containing mean of 38 local cardiac activation intervals before the termination by ICD shock were analyzed. From intracardiac electrogram recordings, the ratio between the short and long term variability (SD1/SD2) and fractal scaling exponent ( &#102 ) were analyzed. After the initial analyses, data sets were randomized and reanalyzed. Local activation dynamics were then also compared in seven patients with both sustained and spontaneously terminating VF episodes. RESULTS. Randomization caused a change in the VF dynamics from organized toward less organized dynamics ( &#102 ) from 1.08 &#45 0.57 to 0.81 &#45 0.45, P < 0.05 and SD1/SD2 from 0.80 &#45 0.23 to 1.04 &#45 0.20, P < 0.01). Spontaneously terminating VF showed more organized dynamics than sustained VF terminated by shock (P < 0.05). CONCLUSIONS. Local cardiac activation dynamics during initial phase of human VF shows organized dynamics. Spontaneously terminating VF episodes have more structured dynamics than sustained VF. Thus, the dynamic behavior of local cardiac activation intervals may be related to the maintenance of ventricular tachyarrhythmias.     

Muscle sympathetic nerve activity at rest compared to exercise tolerance

Cardiovascular autonomic function is associated with physical performance and exercise training adaptation. The association between physical performance and sympathetic regulation is not well known. We hypothesized that sympathetic nervous system activity is associated with physical performance among male runners. The study population included 26 healthy male club runners [age 33 ± 5 years, body mass index (BMI) 24 ± 1 kg/m², VO_2max 58 ± 5 ml kg⁻¹ min⁻¹; mean ± SD]. Muscle sympathetic nerve activity (MSNA) was assessed from the peroneal nerve by the microneurography technique during 5 min of supine rest. Physical performance was assessed by time to exhaustion during treadmill running. The mean resting MSNA was 20 ± 6 bursts min⁻¹ (range 6–34). The mean time to exhaustion was 1,005 ± 136 s (range 720–1260). When the study group was divided into tertiles according to their running performance (866 ± 69, 994 ± 30 and 1154 ± 71 s in time to exhaustion, P < 0.0001 between the groups), MSNA was lower (P = 0.032) in the group with the best running performance (16 ± 5 bursts min⁻¹) compared to those with the worst running performance (23 ± 7 bursts min⁻¹). In conclusion, baseline sympathetic activity, measured by a microneurography at rest, may be associated with the maximal running performance of healthy subjects.