Abstracts of papers presented at the Japanese–European Kobe Symposium on Thrombosis, 6–7 November 2000, Kobe Gakuin University,Kobe, Japan

Platelet activation leads to the initiation of intracellular signalling processes, many of which are triggered by Ca²⁺. We have studied the involvement of exogenous Ca²⁺ in platelet response to collagen activation. Platelet suspensions were prepared with and without adding external calcium in the suspension buffers. Activation with collagen (Col-I) was carried out, before and after incubation with cytochalasin B (Cyt-B) to block the actin assembly and the cytoskeletal reorganization. We evaluated changes in (i) tyrosine phosphorylation of proteins, in platelet lysates and associated with the cytoskeletal fraction, (ii) the association of contractile proteins to the cytoskeleton, (iii) expression of intraplatelet substances at the surface, and (iv) cytosolic Ca²⁺ levels ([Ca²⁺]_i). Ultrastructural evaluation of platelets by electron microscopy was also performed. Platelet activation by Col-I in the absence of added Ca²⁺ was followed by mild association of actin and other contractile proteins, low phosphorylation of proteins at tyrosine residues, lack of expression of intraplatelet substances at the membrane, and absence of aggregation. In the presence of millimolar Ca²⁺, Col-I induced intense actin filament formation with association of contractile proteins with the cytoskeleton, resulting in profound morphological changes. Under these conditions, Col-I induced signalling through tyrosine phosphorylation, with increases in the [Ca²⁺]_i, release of intragranule content and aggregation. Inhibiting actin polymerization with Cyt-B prevented all these events. Our data indicates that platelet activation by collagen requires external Ca²⁺. Studies with Cyt-B indicate that assembly of new actin and cytoskeleton-mediated contraction, both dependent on exogenous Ca²⁺, are key events for platelet activation by collagen. In addition, our results confirm that entrance of exogenous Ca²⁺ depends on a functional cytoskeleton.     

Abstracts presented at the 14th European Colorectal Congress (#ECCStGallen), 29.11.2020–2.12.2020, St.Gallen,Switzerland

Techniques in Coloproctology -     

Abstracts of papers presented at the XVth European Symposium on Blood Platelets, 19–21 October 2000, Bischenberg,Alsace, France

To establish the possible influence of isatin (2,3-dioxo-indole) on the activity of platelets, the effects of isatin on platelet eicosanoid synthesis were studied in rats. Different doses (12.5–50?mg/kg) of isatin were injected intraperitoneally (i.p.) and the effects on the arachidonate cascade of isolated platelets were investigated. Cells were labeled with [¹⁴C]arachidonic acid, then the eicosanoids were separated with overpressure thin-layer chromatography and were quantitatively determined with a liquid scintillation analyzer. The lipoxygenase pathway was significantly inhibited by isatin (50?mg/kg) treatment and also the overall activity of the arachidonate cascade was diminished; however, the cyclooxygenase system was significantly stimulated. A 50-mg/kg i.p. dose of isatin significantly increased the production of vasoconstrictor cyclooxygenase metabolites. Among the vasodilator cyclooxygenase products, the synthesis of PGE2 and PGD2 were significantly decreased while that of 12-hydroxyheptadecatrienoic acid (HHT) increased upon isatin (50?mg/kg) administration. Our results provide further evidence on the peripheral actions of isatin and suggest that this endogenous indole may induce significant changes in the production of blood platelet arachidonic acid metabolites, which are important regulatory substances, thus isatin may potentially affect an even broader range of functions than was previously assumed.     

Abstracts of the 27th Annual Conference of APASL,March 14–18, 2018, New Delhi,India

Background and aims

Spontaneous bacteremia is a poorly characterized infection in patients with cirrhosis. We compared the incidence of mortality and acute kidney injury in patients with spontaneous bacterial peritonitis and spontaneous bacteremia, and identified risk factors for mortality and acute kidney injury in patients with spontaneous bacteremia.

Methods

We performed a retrospective cohort study of patients with cirrhosis and spontaneous bacteremia or spontaneous bacterial peritonitis from 2008 to 2016 at Hospital Italiano, Buenos Aires. We compared the cumulative incidence of acute kidney injury and death between the two infections, and identified risk factors for these outcomes in patients with spontaneous bacteremia.

Results

Seventy-one patients with spontaneous bacteremia and 55 patients with spontaneous bacterial peritonitis were included. Most infections were nosocomial. Overall, 26% of bacteria were resistant and 11% multi-resistant. We found no significant association between acute kidney injury [subhazard ratio (sHR) 1.05 (95% confidence interval, CI 0.67–1.63, p = 0.83)] or death [sHR 1.15 (95% CI 0.60–2.20, p = 0.68)] and type of spontaneous infection in multivariate analyses adjusting for basal Model for End-Stage Liver Disease (MELD) score. In patients with spontaneous bacteremia, baseline MELD score was independently associated with acute kidney injury [sHR 1.07 (95% CI 1.03–1.11, p = 0.001)] and death [sHR 1.07 (95% CI 1.02–1.15, p = 0.03)].

Conclusions

Short-term acute kidney injury and mortality rates were similar in patients with spontaneous bacteremia and spontaneous bacterial peritonitis. Risk assessment of patients with spontaneous bacteremia can be performed with baseline MELD score.

     

Hungarian Hospital Antibiotic Consumption at the Regional Level, 1996–2005

Abstract Background:   Regional variations in antibiotic consumption in outpatients have been reported previously, but nothing is as yet known about the regional distribution of antibiotic consumption in the hospital sector in Hungary. This study was designed to explore regional variations and investigate determinants of antibiotic consumption in hospital care in Hungary. Materials and Methods:   Regional distribution-based antibiotic sales data were obtained for a 10-year period (1996–2005) for the 20 Hungarian counties. Systemic antibacterial use (Anatomical Therapeutic Chemical code: J01) was expressed as the number of defined daily doses (DDD) per 100 patient-days. The multiple linear regression model was applied to investigate the determinants of regional differences in hospital antibiotic consumption. Independent variables related to health care access, utilization of hospital resources, doctors’ workload, type of hospital care provided, and patient’s characteristics and infections were considered as possible determinants, and data on these variables were obtained for 2 years (2004, 2005). We also tested the association between hospital and ambulatory care antibiotic consumption in Hungarian regions using the Pearson correlation test. Results:   For each year during the 1996–2005 study period, there were large and stable variations in total hospital antibiotic consumption (e.g., min–max₁₉₉₆: 16.0–28.2; min–max₂₀₀₅: 15.2–32.2 DDD per 100 patient-days) depending on the region. In the two developed models (Model 1 and Model 2), the number of reported infections accounted for 53% of the observed regional variations in hospital antibiotic consumption (Model 1), and the number of reported infections together with the case-mix index were responsible for 61% (Model 2) . Total antibiotic consumption in hospitals showed a positive correlation (R = 0.71, p = 0.002) with total antibiotic consumption in ambulatory care. Conclusion:   The case-mix index and the number of reported infections explained some of the observed regional variations. However, the moderate value of the models in explaining these regional variations suggest that determinants which could not be explored in this preliminary study may also contribute to regional differences. Future studies should aim at collecting data for each individual hospital as well as data on possible determinants for hospital antibiotic consumption.