Probable role of endogenous endotoxins in hepatocytolysis during murine hepatitis caused by frog virus 3

Three new observations bear out the role of endogenous endotoxins in the pathogenesis of murine hepatitis caused by frog virus 3. First, the LD50 of endotoxin is 20 times lower in mice pretreated for 2.5 hr with a sublethal dose of frog virus 3 than in untreated mice. Animals inoculated with one sublethal dose of lipopolysaccharide 2.5 hr after injection of one sublethal dose of virus die, all having developed extensive hepatocellular necrosis. This hypersensitivity varies according to the intensity of virus-induced destruction of Kupffer cells, which are the intrahepatic target of the virus. Second, mortality is significantly lower and the interval between infection and death longer in axenic mice, which are largely protected from portal endotoxemia. Third, the impairment of some biologic activities of endotoxin (through treatment with polymyxin B or indomethacin, for example) protects mice against hepatic damage and death. Likewise, mice rendered tolerant to endotoxins, and C3H/HeJ mice, which are genetically resistant to endotoxins, survive challenge with frog virus 3 and are refractory with regard to hepatocytolysis . These findings suggest that, in hepatitis caused by frog virus 3, endogenous endotoxins are responsible for extensive hepatocytolysis since virus-induced damage to the hepatic reticuloendothelial system prevents their detoxification.     

Echocardiographic diagnosis of anomalous origin of the left coronary artery from the pulmonary artery.

We found increased systolic coronary flow in transthoracic pulsed wave (PW) Doppler in a 42-year-old patient with anomalous origin of left main coronary artery from the pulmonary artery. This is a characteristic echocardiographic finding in this anomaly in the presence of collateral circulation and coronary L-R shunt. In comparison with so far used echocardiographic criteria this parameter when present allows quick recognition of anomalous origin of left coronary artery from the pulmonary artery, and its differentiation from other potentially lethal coronary anomalies.     

Utility of a new assay for carbohydrate-deficient transferrin (Biorad %CDT TIA) to monitor abstinence during a treatment outcome study

BACKGROUND: The ability to reliably detect heavy alcohol use is important in both clinical and research populations. The current study evaluates the utility of the newest method of measuring carbohydrate deficient transferrin (CDT) in monitoring the abstinence during a treatment outcome study. METHODS: Blood from 40 alcohol dependent individuals was obtained at baseline and at weeks 4, 8, and 12 of treatment. Differences in percent of baseline GGT and %CDT levels were analyzed in people who remained abstinent throughout treatment (abstainers) and in those who consumed alcohol during treatment (drinkers). RESULTS: There was a significant decrease in the percent of baseline %CDT levels in the subjects who abstained at week 4 and a trend at weeks 8 and 12. Conversely, there were no significant differences in percent of baseline GGT levels between drinkers and abstainers at any time point. CONCLUSIONS: Although small in nature, this study provides preliminary evidence for the use of the relatively new Biorad %CDT assay to monitor drinking status during treatment outcome studies. This study is also consistent with previously reported findings that GGT appears to be less sensitive than %CDT in detecting the consumption of alcohol. A larger trial focusing on sex differences in the utility of % CDT to monitor outcome would be of interest.     

Use of abciximab prior to primary angioplasty in STEMI results in early recanalization of the infarct-related artery and improved myocardial tissue reperfusion - results of the Austrian multi-centre randomized ReoPro-BRIDGING Study.

AIMS: The aim of the ReoPro-BRIDGING Austrian multi-centre study was to investigate the effects of abciximab (ReoPro) on early reperfusion in ST-elevation myocardial infarction prior to or during primary percutaneous coronary angioplasty (pPCI). METHODS AND RESULTS: Fifty-five patients with STEMI were randomized either to start abciximab (0.25 mg/kg bolus followed by 10 microg/min infusion) during the organization phase for pPCI (Group 1, n=28) or immediately before pPCI (Group 2, n=27). The time between first bolus of abciximab and first balloon inflation of pPCI was 83+/-18 vs 21+/-13 min in Group 1 vs 2. The pre-pPCI ST-segment resolution (55+/-21.4% vs 42.4+/-18.2%, p=0.005), TIMI flow grade 3 (29% vs 7%, p=0.042), corrected TIMI frame count (58.4+/-32.7 vs 78.9+/-28.4 frame, p=0.018) %diameter stenosis (76.3 /63.5-100/ vs 100 /73.5-100/; median /interquartile range/, p=0.023), were significantly higher in Group 1 vs Group 2. Quantitative myocardial dye intensity measurement revealed a significantly higher grade of myocardial tissue perfusion (1 /0-9.25/ vs 0 /0-3.0/ grey pixel unit, p=0.048) in Group 1 before pPCI. Rapid release of cardiac enzymes was observed in Group 1 as compared with Group 2: rate of rise of CK was 210+/-209 vs 97+/-95 U/l/h (p=0.015). QRS score indicated a smaller infarct size in Group 1 (4.8+/-3.8 vs 7.6+/-3.5, p=0.011) on day 7. CONCLUSION: The use of abciximab in the organization phase for pPCI results in signs of early recanalization of the infarct-related artery and a subsequent improved myocardial tissue reperfusion.     

Angiogenic growth factors and hypertension

Emerging evidence supports a novel view of hypertension as a disease of inadequate or aberrant responses to angiogenic growth factors (AGF). Patients with hypertension have reduced microvascular density, with some evidence supporting a primary role for rarefaction in causing hypertension. Two clinical models have demonstrated a link between inhibition of AGF activity and hypertension. A major side effect of bevacizumab, a monoclonal antibody to vascular endothelial growth factor (VEGF), is hypertension. Pre-eclampsia is accompanied by high circulating levels of soluble VEGF receptor-1, which forms inactive complexes with VEGF and placental growth factor (PlGF). Paradoxically, early studies have demonstrated high circulating levels of AGF in hypertension. Several mechanisms may account for this finding including increased vascular stretch, tissue ischemia, compensatory responses, decreased clearance or a combination of these mechanisms. High AGF in hypertension could contribute to clinical sequelae such as peripheral and pulmonary edema, microalbuminuria, and progression of atherosclerosis. However, a role for altered angiogenesis in the pathogenesis of hypertension or its sequelae has not been established. Novel studies to understand the roles of AGF in hypertensive patients are warranted.     

Impact of patient-prosthesis mismatch and aortic valve design on coronary flow reserve after aortic valve replacement.

OBJECTIVES: This prospective-randomized study investigated the effect of aortic valve design and patient-prosthesis mismatch (PPM) on coronary flow reserve (CFR) after mechanical or biological aortic valve replacement (AVR) in patients with aortic stenosis (AS). BACKGROUND: Coronary flow reserve may be an important parameter of long-term survival after AVR in patients with AS. Reduced CFR may contribute to more cardiovascular events and greater rates of mortality. METHODS: A total of 48 patients undergoing AVR underwent magnetic resonance imaging for the measurement of coronary flow preoperatively, 5 days postoperatively, and at 6-month follow-up with measurement of CFR. Patients scheduled for mechanical AVR were randomized to a tilting disc or bileaflet prosthesis (n = 12 in each group). For biological AVR, patients were scheduled to receive a stented (n = 12) or stentless (n = 12) valve. Patients also underwent echocardiography with measurement of transvalvular pressure gradients and left ventricular mass regression. RESULTS: Postoperatively, coronary flow increased significantly in all groups (p < 0.001). Only stentless valves demonstrated a normal CFR (3.4 +/- 0.3 vs. 2.3 +/- 0.1 for stented biological valves, 2.1 +/- 0.2 for tilting disc, and 2.2 +/- 0.3 for bileaflet mechanical valves). Patient-prosthesis mismatch with an indexed effective orifice area <0.85 cm2/m2 led to decreased rates of CFR in the tilting disc, stentless, and stented groups. Pressure gradients were 14 +/- 3 mm Hg for tilting disc, 12 +/- 4 mm Hg for bileaflet, 19 +/- 6 mm Hg for stented, and 10 +/- 4 mm Hg for stentless valves. CONCLUSIONS: Normalization of CFR after AVR in patients with AS was observed only for stentless valves. Coronary flow reserve might explain the excellent long-term results for stentless valves. (Impact of Patient-Prosthesis Mismatch on Coronary Flow Reserve; http://www.clinicaltrials.gov/ct/show/NCT00310947?order=1; NCT00310947).     

Effects of epoprostenol on right ventricular hypertrophy and dilatation in pulmonary hypertension

OBJECTIVES: To gain more knowledge of changes in main pulmonary artery flow and right ventricular mass and volumes in patients with pulmonary hypertension during epoprostenol therapy. METHODS: Eleven patients (9 women) were evaluated before the start of therapy and every 4 months thereafter. Right and left ventricular volumes and masses were measured by cine MRI. Flow was measured with MRI velocity quantification. At the same times, 6-min walking tests were performed. Right-heart catheterizations were performed at baseline and after 1 year. RESULTS: Right ventricular mass in the patient group was significantly higher from that in a control group of healthy volunteers (95 +/- 26 g vs 42 +/- 10 g, p < 0.05 [mean +/- SD]), whereas the stroke volume was lower (34 +/- 11 mL vs 81 +/- 11 mL, p < 0.05). The greatest improvement in right ventricular stroke volume (to 41 +/- 11 mL, p < 0.05) took place in the first 4 months. During the 1-year follow-up, right ventricular end-diastolic volume and mass did not change, and mean pulmonary artery pressure remained nearly stable at 55 mm Hg at baseline and 53 mm Hg after 1 year. Pulmonary vascular resistance decreased by 12.5% (p = 0.06). CONCLUSIONS: From these data we conclude that epoprostenol lowers pulmonary vascular resistance, leading to an increase in pulmonary artery flow. This increase in pulmonary artery flow corresponds well with the increase in 6-min walking distance and can be noninvasively monitored by MRI (flow quantification). Right ventricular dilatation and hypertrophy are not reversed by epoprostenol therapy, but do not progress either.     

Abnormal cytokine and adrenocortical hormone regulation in myotonic dystrophy

Metabolic-endocrine dysfunctions, including hyperinsulinemia, hypertriglyceridemia, increased fat mass, and dysregulation of the hypothalamic-pituitary-adrenal axis, are common in myotonic dystrophy (MD). We hypothesized that increased production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) may be important underlying mechanisms. We studied the diurnal rhythmicity of cytokines and cortisol, ACTH, and dehydroepiandrosterone in 18 men with adult onset MD and 18 controls. Morning levels of androstenedione, 17-hydroxyprogesterone, testosterone, and insulin were also determined. Genetic analyses were performed, including calculation of allele sizes. Median circulating 24-h levels of IL-6 (P < 0.001), TNF-alpha (P = 0.05), ACTH (P < 0.05), and cortisol (P < 0.05) were all significantly increased in MD, whereas dehydroepiandrosterone levels were decreased (P < 0.001). The diurnal rhythms of these cytokines/ hormones were disturbed in patients. Morning testosterone levels were decreased and insulin levels increased (P < 0.01 for both). Patients with high body fat mass had significantly increased insulin levels and decreased morning levels of cortisol, ACTH, and testosterone. IL-6 and TNF-alpha levels are increased and adrenocortical hormone regulation is disturbed in MD. Adiposity may contribute to these disturbances, which may be of importance for decreased adrenal androgen hormone production and metabolic, muscular, and neuropsychiatric dysfunction in MD.     

The occurrence of graft-versus-host disease is the major predictive factor for response to donor lymphocyte infusions in multiple myeloma

The graft-versus-myeloma (GVM) effect of donor lymphocyte infusions (DLIs) is well established. We now report the outcome of DLI in 54 patients with relapsed myeloma following allogeneic transplantation. Twenty-eight patients (52%) responded, 19 patients (35%) with a partial response and 9 patients (17%) with a complete response. Progression-free and overall survival were 19 and 23 months, respectively. We found that acute and chronic graft-versus-host disease (GVHD) observed in 57% and 47% of patients, respectively, following DLI were the strongest predictors for response. This suggests that targets for GVHD and GVM are identical. In a subgroup analysis, deletion of chromosome 13, as determined by double-color fluorescence in situ hybridization (FISH), had no impact on outcome, indicating that these patients are candidates for early allogeneic transplantation followed by DLI, in case of insufficient response.     

Investigation of the Lith6 candidate genes APOBEC1 and PPARG in human gallstone disease.

BACKGROUND: Genetic susceptibility contributes to the aetiology of gallbladder diseases as shown by multiple epidemiological studies. A major gallstone susceptibility locus (Lith6) was identified in 2003 by quantitative trait locus mapping in mice. Two attractive positional and functional candidate genes in apolipoprotein B mRNA-editing protein (APOBEC1) and peroxisome proliferator-activated receptor gamma (PPARG) are located in this interval. AIMS: To investigate APOBEC1 and PPARG as candidate genes for common symptomatic gallstone disease in humans. PATIENTS AND METHODS: Eight hundred and ten patients who underwent cholecystectomy for symptomatic gallstone disease (median age of onset 50) were compared with 718 sex-matched control individuals. An independent additional sample included 368 gallstone patients and 368 controls. Control individuals were sonographically free of gallstones. Haplotype tagging and all known coding single nucleotide polymorphisms were genotyped for PPARG (N=32) and APOBEC1 (N=11). RESULTS: The investigated high-risk patient sample provides a power of greater than 80% for the detection of odds ratios down to 1.45. No evidence of association of the two genes in the single-point tagging markers, coding variants and in the sliding window haplotype analysis was detected (all nominal single point P-values >0.04). A logistic regression analysis including age, sex and BMI as covariates was also negative (nominal P-values > or =0.08). CONCLUSIONS: In the investigated German samples, no evidence of association of APOBEC1 and PPARG with gallstone susceptibility was detected. Systematic fine mapping of the complete Lith6 region is required to identify the causative genetic variants for gallstone in mice and humans.