Validation of ultrasonic image boundary recognition in abdominal aortic aneurysm

An aneurysm of the abdominal aorta (AAA) is characterized by modified wall properties, and a balloon-like area usually filled by a thrombus. A rupture of an aortic aneurysm can be fatal, yet there is no way to accurately predict such an occurrence. The study of the wall and thrombus cross-sectional distension, due to a pressure wave, is important as a way of assessing the degradation of the mechanical properties of the vessel wall and the risk of a rupture. Echo ultrasound transverse cross-sectional imaging is used here to study the thrombus and the aortic wall distension, requiring their segmentation within the image. Polar coordinates are defined, and a search is performed for minimizing a cost function, which includes a description of the boundary (based on a limited series of sine and cosine functions) and information from the image intensity gradients along the radii. The method is based on filtering by a modified Canny-Deriche edge detector and then on minimization of an energy function based on five parts. Since echoes from blood in the lumen and the thrombus produce similar patterns and speckle noise, a modified version for identifying the lumen-thrombus border was developed. The method has been validated by various ways, including parameter sensitivity testing and comparison to the performance of an expert. It is robust enough to track the lumen and total arterial cross-sectional area changes during the cardiac cycle. In 34 patients where sequences of images were acquired, the border between the thrombus and the arterial wall was detected with errors less than 2%, while the lumen-thrombus border was detected with a mean error of 4%. Thus, a noninvasive measurement of the AAA cross-sectional area is presented, which has been validated and found to be accurate.

[Five days ceftibuten versus 10 days penicillin in the treatment of 2099 patients with A-streptococcal tonsillopharyngitis]

Group A Streptococci have remained sensitive to penicillins and other betalactam antibiotics, e. g. cephalosporins. Since the beginning of the 1950s oral penicillin V given three times daily in a dose of 50,000 IU daily has been the drug of choice against Group A streptococcal infection. The German Society for Pediatric Infectious Diseases (DGPI) undertook a large scale multicenter randomized study of culture-proven A-streptococcal tonsillopharyngitis to compare the efficacy and safety of a five day regimen of ceftibuten (9 mg/kg KG, once daily) with 10 days of penicillin V (50,000 I.E./kg KG, divided in three doses), testing for equivalence of clinical and bacteriological efficacy. A one year follow-up served to assess poststreptococcal sequelae like rheumatic fever or glomerulonephritis.

RESULTS

The clinical efficacy at the clinical end-point 7-9 days after end of treatment was 86.9% (419/482) for ceftibuten and 88.6% (1,198/1,352) for penicillin V. This result is statistically equivalent (P = 0.0152). Resolution of clinical symptoms was significantly faster in the ceftibuten group (P = 0.043/Fisher-Test) and compliance was significantly superior as well (P (0.001). Eradication of group A streptococci at an early control 2-4 days after end of treatment was not equivalent, 78.49% for ceftibuten and 84.42% for penicillin V (P = 0.5713). Both eradication rates were comparable 7-8 weeks after end of treatment (84.65%, 375/443 ceftibuten vs. 86.82%, 1,067/1,229 penicillin V), the difference not being significant. No cases of poststreptococcal sequelae, e.g. rheumatic fever or glomerulonephritis, attributable to either ceftibuten or penicillin were observed in the course of the study.

Bromelain is an accelerator of phagocytosis, respiratory burst and Killing of Candida albicans by human granulocytes and monocytes

OBJECTIVE

The aim of this study was to examine the influence of immuno modulating agents like bromelain and trypsin (e.g. Wobenzym on granulocyte and monocyte functions in healthy volunteers and patients with disorders of the humoral immuno system X-linked agammaglobulinaemia (XLA) and common variable immuno deficiency (CVID) and to find out whether the unspecific immunity could be improved by these enzymes.

METHODS

In a whole-blood assay kinetics of phagocytosis, respiratory burst and killing (PBK) were measured in blood samples incubated with and without bromelain and trypsin (B/T) using Candida albicans as target organism. The time-reaction curves were analysed determining their gradient (T1) and their onset (T2) as well as the half effect time (HET).

RESULTS

Phagocytes from patients with XLA showed a significantly accelerated basal phagocytosis (reduction of HET by 24% p < 0.001) compared to healthy controls. After incubation with B/T (10 microg/ml each) speed of phagocytosis was nearly doubled (phagocyte activity p < 0.0001, Candida uptake p < 0.003), T2 of respiratory burst was reduced by 65 % (p < 0.0001) and killing was accelerated by 27% (p < 0.046). However, the maximal activities of all kinetics were not altered. Incubation of phagocytes from healthy controls with B/T accelerated phagocytosis to a level comparable to that of untreated phagocytes from patients with XLA and also accelerated reactive oxygen species (ROS) production (reduction of HET by 28%, p < 0.012). In contrast to phagocytes from patients with XLA, phagocytes of patients with CVID showed a similar stimulation by B/T like healthy controls. Further experiments with the single substances showed that bromelain was the active compound.

CONCLUSION

Our data suggest, that bromelain possesses immuno stimulatory properties. Phagocytes of XLA patients appear to be particularly susceptible to this stimulation.

[Value of pneumococcal vaccination in infants and young children]

Streptococcus pneumoniae is a common cause of meningitis, sepsis, pneumonia, acute otitis media, and sinusitis in children. Children younger than 24 months have the highest rates of invasive pneumococcal infections (Germany 1997-1999: 19.5/100,000/year). Pneumococcal infections cause in Germany 220-250 cases of meningitis, about 50,000 of pneumonia (children younger than 5 years) and more than 1 million cases of otitis media (children) annually. The case-fatality rate for invasive pneumococcal diseases is high (1997-1999 5.5%, meningitis 8.3%). 20-30% of survivors from meningitis suffer from CNS-related sequelea. In children up to 2 years vaccination with the heptavalent pneumococcal conjugate vaccine can reduce invasive pneumococcal diseases by about 80% and otitis media and recurrent otitis media by 6% and 9-16%, respectively. Due to the increased risk of pneumococcal infections in the first two years of live all children of this age group should be vaccinated. The high rate of resistance of pneumococci against macrolides in Germany, the high rate of non-licensed antibiotics in infants and the inefficacy of the 23-valent vaccine in children younger than 2 years makes the new vaccine to a necessary alternative.

Management of sepsis and septic shock in infants and children

Sepsis and septic shock constitute an important cause of morbidity and mortality in critically ill children. Thus, the systemic response to infection and its management remains a major challenge in clinical medicine. Apart from antibiotic administration, the majority of available therapies are limited to supportive strategies, although considerable efforts are being undertaken to devise innovative approaches that modulate host inflammatory responses. In suspected sepsis, 2 or 3 days' empiric antibiotic therapy should begin immediately after cultures have been obtained without awaiting results. Antibiotics should be re-evaluated when the results of the cultures and susceptibility tests are available. The initial antibiotic (combination) is determined by the likely causative agent, susceptibility patterns within a specific institution, CNS penetration, toxicity, and the patient's hepatic and renal function. The likely offending micro-organism in turn depends primarily on the patient's age, coexistence of any premorbid condition leading to impaired immune response, and the presenting signs and symptoms. Close attention to cardiovascular, respiratory, fluid and electrolyte, haematological, renal and metabolic/nutritional support is essential to optimise outcome. Fluid resuscitation is of utmost importance to overcome hypovolaemia on the basis of a diffuse capillary leak. Monitoring and normalisation of the heart rate is essential. In case of nonresponse to fluid resuscitation, inotropic and vasoactive agents are commonly used to increase cardiac output, maintain adequate blood pressure and enhance oxygen delivery to the tissue. Because respiratory distress syndrome is seen in about 40% of critically ill children with septic shock, increased inspired oxygen is essential. To provide optimal relief from respiratory muscle fatigue and facilitate the provision of positive airway pressure, early intubation and mechanical ventilation should be considered. Renal support is essential to avoid prolonged renal shutdown in hypoperfusion states. Haematological support comprises replacement therapy of clotting factors to overcome disseminated intravascular coagulation. Metabolic support may include glucose support, extraction of ammonia from the body and recognition of liver dysfunction. Nutritional support may modify the inflammatory host response, and early enteral feeding can improve outcome in critical illness. To date, glucocorticoid and non-glucocorticoid anti-inflammatory agents have not shown significant benefit in septic patients.

Comparative efficacy of clarithromycin modified-release and clarithromycin immediate-release formulations in the treatment of lower respiratory tract infection

BACKGROUND

A modified-release (MR) formulation of clarithromycin, distinct from the extended-release formulation, has recently been developed and has efficacy and tolerability similar to standard immediate-release (IR) clarithromycin, with the advantage of once-daily dosing.

OBJECTIVE

The purpose of this study was to compare the efficacy (as measured by relief of clinical symptoms and eradication of specific pathogens) and tolerability of clarithromycin MR 500 mg administered once daily versus clarithromycin IR 250 mg administered twice daily for 5 days.

METHODS

In this randomized, double-blind (with matching placebo), parallel-group. multicenter, controlled trial, patients with lower respiratory tract infection were randomized to 1 of 2 treatment regimens: clarithromycin MR 500 mg once daily plus clarithromycin IR 250 mg placebo twice daily or clarithromycin IR 250 mg BID plus clarithromycin MR 500 mg placebo once daily.

RESULTS

Statistically equivalent clinical cure and success rates, overall symptomatic improvement, and bacteriologic responses were achieved with both treatments. In the clarithromycin MR group, the clinical cure rate was 72.5% (87/120), and the clinical success rate (cure plus symptomatic improvement) was 97.5% (117/120). Of the 124 patients treated with clarithromycin IR 250 mg BID, 98 (79.0%) achieved a clinical cure, and 120 (96.8%) achieved clinical success. There were no statistically significant between-group differences in clinical cure or success rates. More than 85% of patients in both study groups experienced improvement in dyspnea, cough, wheezing, chest discomfort, fatigue, and fever, and the visual appearance of sputum: these symptoms resolved completely in the majority of patients. Bacteriologic response (efficacy against specific pathogens), which was assessed as an objective efficacy criterion, was assessable for 40 patients treated with clarithromycin MR and 49 patients treated with clarithromycin IR. Bacteriologic eradication of the pretreatment target pathogen was achieved in 95.0% (38/40) of assessable patients treated with clarithromycin MR 500 mg once daily and 91.8% (45/49) of patients treated with clarithromycin IR 250 mg BID. Treatment-related adverse events were mild to moderate in all cases. Nausea (n = 9), diarrhea (n = 6), abdominal pain (n = 5), and gastric pain (n = 3) were the only study drug-related adverse events reported by > or = 1 patient in each treatment arm. Diarrhea was reported only in the clarithromycin IR group (n = 6) (P = 0.029 vs clarithromycin MR).

CONCLUSIONS

Clarithromycin MR 500 mg administered once daily for 5 days is as effective and well tolerated as the IR formulation, with the advantage of once-daily dosing and fewer episodes of diarrhea.