Jiri Benes

Acute bacterial meningitis in adults : Predictors of outcome

Case fatality ratio and permanent sequelae of acute bacterial meningitis remain high in recent decades. A prospective longitudinal study of adult patients admitted with community acquired acute bacterial meningitis at a tertiary infectious diseases unit aimed to identify predictors of unfavourable outcome – death and sequelae. Anamnestic, clinical and laboratory data and clinical outcome were recorded. From 1997 to 2006, 279 adults (122F, 157M) with a median age of 51 y were admitted with acute bacterial meningitis. Predisposing condition and comorbidity were recorded in 42% and 38% of patients, respectively. Time between symptoms onset and antibiotic treatment ranged from 6 to 160 h. An aetiological agent was identified in 77% of patients: Streptococcus pneumoniae (29%) and Neisseria meningitidis (27%) were the most frequent. 55 patients (20%) died and 63 (23%) had neurological sequelae 6 months after discharge. In multivariate analysis, 7 independent predictors of unfavourable outcome were identified: internal comorbidity, time to treatment >48 h, coma, hypotension, high CSF protein, low glucose ratio, and non-meningococcal aetiology. The results suggest that acute bacterial meningitis remains associated with significant morbidity and mortality. Maintaining a high clinical suspicion and initiating appropriate diagnostic testing and therapeutic interventions promptly are essential for an optimal clinical outcome.

Localized damage of tissues induced by focused shock waves

A novel method for generation of focused shock waves has been developed. A cylindrical pressure wave, created by a high-voltage multichannel discharge in water with an increased electrical conductivity, is focused by a metallic parabolic reflector. The discharge is formed on a composite anode consisting of a cylindrical stainless steel electrode covered by a thin porous ceramic layer. In such an arrangement at the applied voltage of 30 kV, a large number of short discharge channels distributed homogeneously on the anode surface is initiated. Each discharge channel creates a semi-spherical pressure wave, and by superposition of all of the waves, a cylindrical pressure wave propagating from the anode is formed. The cylindrical pressure wave is focused by a metallic parabolic reflector (cathode) and near the focus it is transformed into a strong shock wave. The focal volume is 2.5 mm in diameter and 32 mm long. We have demonstrated that the focused shock waves destroy human red blood cells (erythrocytes) very efficiently. Interaction of the focused shock waves with fresh potatoes that have high water content have been used to assess the mechanical effects of the waves. The 6-cm-thick slab of potato was placed next to the focal region and exposed to 10 shocks at 30 kV. The experiment demonstrated that only the focal region inside the potato had been damaged and no damage was seen between the potato surface and the focal region. Local injury of animal liver tissues exposed to the shock waves were observed in vitro. Livers of three rabbits have been exposed in vivo. Histological analysis of the exposed tissues revealed injuries and hemorrhages at the focal region of the shock waves.

Hypothermic anticoagulation: testing individual responses to graded severe hypothermia with thromboelastography.

Selective incircuit blood cooling could be an effective anticoagulation strategy during hemodialysis. However, it is currently unknown what blood temperature would ensure sufficient anticoagulation. Similarly, no information exists about potential interindividual variability in response to graded hypothermia. Therefore, the aim of this study was to analyze effects of profound hypothermia on human coagulation. Furthermore, a mathematical relationship between blood temperatures and coagulation was sought to predict individual responses to blood cooling. It was designed as a laboratory study. Thromboelastography (TEG) measurements were taken at a temperature range of 38–12°C. To enable measurements below 20°C, the TEG device was placed into an air conditioned chamber allowing for setting of the temperatures over a wide range. The data were analyzed by regression analysis for pooled and individual measurements. Decreasing temperatures always led to a progressive reduction in blood coagulation by delaying the initiation of thrombus formation, as well as by decreasing the speed of its creation and growth. However, the response to cooling was not uniform and the interindividual variability exists. The relationship between blood temperature and coagulation is not linear but exponential (parameters R and K) and sigmoid (parameter &agr;-angle). The lower the blood temperature, the more significant effect on blood coagulation decline. To predict an individual response of the coagulation system over a wide range of temperatures, a mathematical modeling can be used.

Movement of the patient and the cone beam computed tomography scanner: objectives and possible solutions

OBJECTIVE This study aimed (1) to determine whether scanner arm rotation causes significant movement of the head restraint and (2) to measure patient movement and its variation during the scan. STUDY DESIGN The iCAT scanner and a high-speed camera were used. The 40 patients were divided into 2 groups: the open-eyed group and the blindfolded group. RESULTS The mean level of head restraint movement was 0.130 mm, with a significantly higher level at the beginning, probably owing to the accelerating arm. Mean movement of patients was 1.135 mm and 1.119 mm in the open-eyed and blindfolded groups, respectively. Patient movement was also significantly higher at the beginning of the scan, when noise and vibrations are likely to surprise the patient. CONCLUSIONS Patient instruction and a dry-run scan should be done by clinicians. Manufacturers should consider separating the seat and head restraint from the rest of the scanner to avoid vibration transfer.

Incidence, predisposing factors, and aetiology of infective endocarditis in the Czech Republic.

Abstract Objectives: The aim of this study was to evaluate the incidence and epidemiological characteristics of infective endocarditis (IE) in the Czech Republic. These results represent the first data on the epidemiology of IE from the post-communist countries. Methods:This was a prospective multi-centre observational study monitoring the occurrence of IE in the catchment areas of 29 hospitals during a 12-month period. The total monitored territory involved a population of 3.9 million people (37.7% of the total Czech population). Patients were included in the study if they had a diagnosis of possible or definite endocarditis according to the modified Duke criteria. Results: One hundred and thirty-four episodes of IE in 132 patients were reported. Thus the crude incidence of IE was 3.4 cases/100,000 inhabitants/y. Vegetations were most frequently found on the aortic and mitral valves. The most frequent agent was Staphylococcus aureus (29.9%). The aetiology remained unexplained in 33.6% of cases, mainly because of previous antibiotic therapy. Surgical intervention during antibiotic therapy was performed in 36 patients (27.5%). Thirty-six patients died during hospitalization (in-hospital mortality rate 27.5%). The most common predisposing cardiac factors were remote cardiac surgery (19.4%) and degenerative valvular changes (11.9%). The most common extracardiac factors were pyogenic infections of skin and soft tissues (13.0%) and chronic haemodialysis (8.2%). Conclusions: Our results document the changing epidemiological characteristics of IE, namely an increasing incidence of the disease and an increasing role of Staphylococcus aureus as a major pathogen. A shift was evident in predisposing factors for IE: almost 39% of IE episodes were associated with both cardiac and extracardiac modern medical procedures.

Tricuspid valve endocarditis due to Neisseria cinerea.

Reported here is a case of infective endocarditis caused by the saprophytic species Neisseria cinerea. To the best of our knowledge, this etiology has not been documented in the medical literature previously. The patient was an intravenous drug addict who developed tricuspid endocarditis with lung embolism. The disease was cured after treatment with ampicillin/clavulanate that was changed to ceftriaxone after an embolic event.

In vivo effects of focused shock waves on tumor tissue visualized by fluorescence staining techniques

Shock waves can cause significant cytotoxic effects in tumor cells and tissues both in vitro and in vivo. However, understanding the mechanisms of shock wave interaction with tissues is limited. We have studied in vivo effects of focused shock waves induced in the syngeneic sarcoma tumor model using the TUNEL assay, immunohistochemical detection of caspase-3 and hematoxylin-eosin staining. Shock waves were produced by a multichannel pulsed-electrohydraulic discharge generator with a cylindrical ceramic-coated electrode. In tumors treated with shock waves, a large area of damaged tissue was detected which was clearly differentiated from intact tissue. Localization and a cone-shaped region of tissue damage visualized by TUNEL reaction apparently correlated with the conical shape and direction of shock wave propagation determined by high-speed shadowgraphy. A strong TUNEL reaction of nuclei and nucleus fragments in tissue exposed to shock waves suggested apoptosis in this destroyed tumor area. However, specificity of the TUNEL technique to apoptotic cells is ambiguous and other apoptotic markers (caspase-3) that we used in our study did not confirmed this observation. Thus, the generated fragments of nuclei gave rise to a false TUNEL reaction not associated with apoptosis. Mechanical stress from high overpressure shock wave was likely the dominant pathway of tumor damage.

Listeria monocytogenes meningitis in adults: the Czech Republic experience.

Background. Listeria monocytogenes (LM) is currently the third most frequent pathogen of bacterial meningitis in adults. Methods. A prospective study of patients with LM meningitis in a Czech tertiary care hospital, carried out from 1997 to 2012. Results. Thirty-one patients were diagnosed with LM meningitis, which was 7% of a total of 440 adult patients with acute bacterial meningitis (ABM) over a 16-year period. Their median age was 63 years, range 26–80 years. Nineteen patients (61%) had underlying immunocompromising comorbidity; 15 patients (48%) were older than 65 years. Fourteen patients (45%) had arterial hypertension. The typical triad of fever, neck stiffness, and altered mental status was present in 21 patients (68%). The median count of cerebrospinal fluid (CSF) leukocytes was 680/μL, protein level 2.6 g/L, and glucose ratio 0.28. Four patients (13%) died, and nine (29%) survived with moderate to severe sequelae. Conclusion. LM meningitis is known to affect immunosuppressed and elderly patients. Arterial hypertension seems to be another important predisposing factor. Clinical symptoms, CSF findings, and disease outcomes, did not significantly differ from other community-acquired ABM in our study, although the CSF leukocyte count was lower. Ampicillin showed good clinical and bacteriological efficacy in the majority of patients.

Listerial endocarditis in a penicillin-allergic woman successfully treated with a combination of 4 drugs.

A 69-y-old woman with bioprosthetic endocarditis due to Listeria monocytogenes developed an allergic reaction after beginning ampicillin treatment. She was cured with the combination of trimethoprim-sulfamethoxazole, rifampicin and teicoplanin. No immune deficiency was found in the patient.

Biological effects of tandem shock waves demonstrated on magnetic resonance.

OBJECTIVES The shock wave is used for the treatment of kidney stones, eventually of gall stones, for more than 20 years. It is a pressure wave, which breaks through soft tissues easily and it is possible to focus it into a small volume. The excellent results of the treatment of concrements led to considerations about another usage of the shock wave. The research is now concentrated on the possibility of the damage to tumour tissues. METHODS In contrast to concrements tumour tissues are not different from healthy tissues as for their acoustic attributes. That is why a new source of shock waves was used in this work. The source allows generating two successive shock waves focused into a common focus, so-called tandem shock waves. The biological effects of the tandem shock waves generated by the new source on rats hepatic tissue and rabbit femoral muscle in vivo were studied in this work. The damage is demonstrated by magnetic resonance imaging. RESULTS MR images showed tissue damage in focus. There was damage of the liver tissue, muscle and also stomach wall. CONCLUSIONS We found that the tandem shock waves are able to damage the acoustically homogeneous soft tissue in the focus, i.e. in the depth. In tissues in front of the focus, there is, however, no damage (Fig. 10, Ref. 15).