Immunogenicity and safety of rapid scheme vaccination against tick-borne encephalitis in HIV-1 infected persons.

Tick-borne encephalitis (TBE) is a vector-borne infection associated with a variety of potentially serious complications and sequelae. Vaccination against TBE is strongly recommended for people living in endemic areas. There are two TBE vaccination schemes - standard and rapid - which differ in the onset of protection. With vaccination in a rapid schedule, protection starts as early as 4 weeks after the first dose and is therefore especially recommended for non-immune individuals travelling to endemic areas. Both schemes work reliably in immunocompetent individuals, but only little is known about how TBE vaccination works in people with HIV infection. Our aim was to assess the immunogenicity and safety of the rapid scheme of TBE vaccination in HIV-1 infected individuals. Concentrations of TBE-specific IgG > 126 VIEU/ml were considered protective. The seroprotection rate was 35.7% on day 28 and 39.3% on day 60. There were no differences between responders and non-responders in baseline and nadir CD4 + T lymphocytes. No serious adverse events were observed after vaccination. The immunogenicity of the TBE vaccination was unsatisfactory in our study and early protection was only achieved in a small proportion of vaccinees. Therefore, TBE vaccination with the rapid scheme cannot be recommended for HIV-1 infected individuals.

Mifepristone potentiates etoposide toxicity in Hep G2 cells by modulating drug transport.

Etoposide is a well-known and widely used anticancer drug that displays several side effects. In addition, tumors often acquire resistance to this drug. Our aim is to develop a combination therapy that would augment toxicity of etoposide in malignant cells. Based on literature and our experiments, we selected mifepristone (RU486) as a potential supporting molecule that is able to enhance etoposide toxicity against cancer cells. All experiments were performed with Hep G2 cells, a well-known and described human hepatocellular carcinoma cell line. By using xCELLigence system, we demonstrated that mifepristone enhances toxicity of etoposide in a dose dependent manner with concomitant caspase-3 activity. We evaluated upregulation of Bax because mifepristone was demonstrated to modulate proapoptotic Bax protein expression. Our data show only weak and not statistically significant increase of Bax expression. On the other hand, we show that mifepristone increases etoposide toxicity via inhibition of ABC transporters, coupled with significant increase of intracellular etoposide concentration. In conclusion, we demonstrate that mifepristone has a synergistic effect with etoposide treatment in the Hep G2 cells and that the effect is related to ABC transporters inhibition.

[Clinical manifestations of pneumococcal infections and the current prevention options]. / Klinické projevy pneumokokových infekcí a soucasné moznosti prevence.

Pneumococcal infections continue to pose a serious medical problem. A broad range of serotypes, increasing resistance to antibiotics and high pathogenic potential of pneumococci are associated with development of various clinical forms of diseases. Some chronic diseases are an important predisposing factor for development of pneumococcal infections. The most common noninvasive forms of the disease are otitis, sinusitis, conjunctivitis; pneumonia is on the borderline between the invasive and noninvasive forms. Meningitis, sepsis, endocarditis and arthritis all belong to invasive pneumococcal diseases. The diagnosis is based on the so-called classic microbiological and molecular biology methods aimed at determining the pneumococcal serotype. The treatment recommendations are varied, depending on the resistance status in particular geographic regions. Prevention of the infections is primarily based on vaccination. In the past, only polysaccharide vaccine (PPSV23) was available; currently, there are conjugate vaccines (PCVs), either 10-valent (PCV10) or 13-valent (PCV13). Initially, PCVs were used exclusively in children; later, PCV13 was approved for selected indications in the adult population. Since 2013, it has been indicated for both children and adults of all ages. These facts have been incorporated into updated guidelines in various specialties. The future of pneumococcal infection prevention rests with the development of protein vaccines.

[Pneumococcal meningitis in children]. / Pneumokoková meningitida u detí.

OBJECTIVE: Presented are the authors' own experiences with invasive pneumococcal diseases in a group of pediatric inpatients with pneumococcal meningitis treated in the Department of Infectious Diseases, University Hospital and Charles University Faculty of Medicine in Hradec Králové over the last 10 years. MATERIAL AND METHODS: A group of patients aged 0-18 years and hospitalized in the above facility in 2002-2011 was retrospectively assessed. The patients' basic clinical characteristics and treatment outcomes are shown below. RESULTS: Over the study period, 27 children with pneumococcal meningitis were treated; of those, 15 were boys and 12 were girls. The patients' ages ranged from 2 days to 17 years; seventeen children (63 %) were younger than 2 years. On admission, 11 children (40 %) had the infection in the middle ear or paranasal sinuses; intracranial complications were noted in 10 cases. Cerebrospinal fluid culture was positive for Streptococcus pneumoniae in 21 cases. In 6 patients, pneumococcal DNA was determined in the cerebrospinal fluid by PCR. None of the studied patients died. Eight children (29 %) were left with permanent damage; of those, seven had hearing impairment. CONCLUSION: Even today, pneumococcal meningitis in children remains a serious condition posing a risk of dangerous consequence or even death. To the maximum extent possible, prevention should include vaccination, especially in infants and children with the predisposing factors.

Disposition of sanguinarine in the rat.

Sanguinarine is an alkaloid with known antibiotic and anti-inflammatory activity and its pharmacokinetics have been studied in the rat after a single oral dose (10 mg kg(-1) body weight). Alkaloid determination in the plasma and liver was carried out by high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC/ESI-MS). The pharmacokinetic parameters (t(max), c(max), AUC(0-->t) and AUC(0-->infinity)) were determined for sanguinarine and dihydrosanguinarine, the major components detected in plasma. The first step in sanguinarine metabolism in the rat was the reduction of the iminium bond resulting in formation of the less toxic dihydrosanguinarine. Both compounds were completely eliminated from the plasma and liver after 24 h and not detected in urine. After a single oral dose of (3)H-sanguinarine, more than 42% of the ingested radioactivity was present in gastrointestinal tract. Benz[c]acridine, up to date the only sanguinarine metabolite referred to in the literature, was not detected in the plasma, liver or urine.

[Invasive streptococcal infections]. / Invazivní streptokokové infekce.

The severity of streptococcal infections depends upon different virulence of individual strains of its causative agent. The most important species are beta-haemolytic group A streptococci (GAS). Clinical manifestations include skin affections, respiratory tract infections and, in particular, serious systemic invasive infections. The pathogenicity of GAS is derived from cell wall components and extracellular products, especially toxins with properties of the so-called superantigens. Less invasive forms of the disease are include necrotizing fasciitis, myositis, pneumonia, sepsis without focus, arthritis, meningitis, puerperal sepsis, streptococcal toxic shock syndrome (STSS) and severe course of erysipelas and cellulitis with blood culture positive for GAS. In most cases, soft tissue infections dominate, often accompanied by chronic diseases of lower extremities in elderly patients. The other clinical forms are rather rare. In children, the condition is clearly frequently related to chickenpox. The generally accepted therapeutic management comprises comprehensive intensive care, early administration of penicillin in combination with clindamycin, and surgical intervention. The use of intravenous immunoglobulins (IVIG), elimination methods and hyperbaric oxygen are under discussion. The slight increase in cases and ineffective prevention require rapid assessment of diagnosis and adequate treatment as a protracted course of the condition is connected with a high mortality rate.

[Mumps--a reemerging infection? The current incidence of mumps in the East Bohemian region in the Czech Republic]. / Príusnice--znovu se vracející infekce? Soucasná situace ve výskytu príusnic ve východoceském regionu.

A review of mumps outbreaks among both non-vaccinated and vaccinated children and young adults in the East Bohemian region in 2003-2005 is presented. A significant increase in mumps cases was observed over this period. The clinical diagnosis was confirmed serologically by ELISA detection of IgM antibodies and/or IgG seroconversion and increased levels of IgG antibodies. A reverse transcriptase nested PCR was introduced for direct detection of mumps virus RNA from clinical specimens (nasopharyngeal secretion, saliva, CSF and serum). The isolated RNA will be stored for further analysis and mumps virus genotyping attempts, helpful in tracing the virus circulation in the East Bohemia region. Possible causes of the recent significant increase in mumps cases among the vaccinated population in the Czech Republic are discussed.

Chemoenzymatic preparation of silybin beta-glucuronides and their biological evaluation.

Chemoenzymatic glucuronidation of the optically pure silybin A (1) using ovine liver glucuronyl transferase afforded three beta-glucuronides of silybin, substituted at phenolic OH groups at the positions C-20 (2), C-7 (3), and C-5 (4) formed in the yields 27, 62.5, and 2.5%, respectively. Using these standards, it was shown that the main silybin conjugate in humans is its 20-beta-D-glucuronate (2), while the C-7 regioisomer (3) was formed in lower proportion. The rate of conjugation of (natural) silybin diastereomers 10S, 11S and 10R, 11R, and therefore also their metabolism in humans is rather different. The radical scavenging activity of 2 is considerably lower than that of its aglycone (1); however, the activity of 3 is higher than in the silybin. These findings corroborate the hypothesis that, at physiological pH, the exclusive target for one-electron oxidation of the silybin molecule is the o-methoxy-phenolic structure at C-19, C-20. This is first pharmacological study using optically pure silybin.

[The human hepatocyte: I. A model for studying metabolism and toxicity of xenobiotics]. / Lidský hepatocyt: I. Model pro studium metabolizmu a toxicity xenobiotik.

Isolated human hepatocytes have become one of the most attractive experimental approaches to the study of the specific metabolic functions of the human liver, interactions between liver cells and infectious agents, and metabolism and pharmacotoxicity of drugs. Particularly the primary cell culture model provides an in vitro system for investigating specific mechanisms in a precisely controlled conditions. In the present paper the legislative and ethical problems concerning availability of human liver samples, techniques developed for isolation, preservation and cultivation of hepatocytes are discussed. In addition, a comparison of human and rat hepatocyte models in the study of the metabolism and cytotoxicity of taxol is reviewed.

Effect of silymarin on serum cholesterol levels in rats.

Previously we have shown that perorally administered silymarin, a mixture of flavonolignans extracted from the seeds of Silybum marianum, possesses a hypocholesterolemic effect in rats fed high cholesterol diet enriched with fat. The aim of this paper was to complete the data concerning peroral and parenteral administration of silymarin. The rats fed standard laboratory diet did not respond to peroral administration of silymarin by decrease of serum cholesterol, but the mild increase in HDL cholesterol was found. Parenterally injected silymarin failed to reduce serum cholesterol both in rats fed high cholesterol diet and standard laboratory diet. The results suggest that silymarin could act either due to the fat-mediated improved bioavailability and/or by inhibiting of resorption of dietary cholesterol.