Nonactivated titanium-dioxide nanoparticles promote the growth of Chlamydia trachomatis and decrease the antimicrobial activity of silver nanoparticles.

AIMS: Chlamydia trachomatis and herpes simplex virus (HSV) are the most prevalent bacterial and viral sexually transmitted infections. Due to the chronic nature of their infections, they are able to interact with titanium-dioxide (TiO2 ) nanoparticles (NPs) applied as food additives or drug delivery vehicles. The aim of this study was to describe the interactions of these two prevalent pathogens with the TiO2 NPs. METHODS AND RESULTS: Chlamydia trachomatis and HSV-2 were treated with nonactivated TiO2 NPs, silver NPs and silver decorated TiO2 NPs before infection of HeLa and Vero cells. Their intracellular growth was monitored by quantitative PCR. Unexpectedly, the TiO2 NPs (100 µg ml-1 ) increased the growth of C. trachomatis by approximately fourfold, while the HSV-2 replication was not affected. Addition of TiO2 to silver NPs decreased their antimicrobial activity against C. trachomatis up to 27·92-fold. CONCLUSION: In summary, nonactivated TiO2 NPs could increase the replication of C. trachomatis and decrease the antimicrobial activity of silver NPs. SIGNIFICANCE AND IMPACT OF THE STUDY: The food industry or drug delivery use of TiO2 NPs could enhance the growth of certain intracellular pathogens and potentially worsen disease symptoms, a feature that should be further investigated.

Fungaemia caused by Candida pulcherrima.

Although neonatal bloodstream infections may be caused by a variety of fungi, invasive fungaemia due to Candida pulcherrima in a premature neonate has not been previously reported. We describe such a case in which antifungal susceptibility test data led to successful therapy. A colonized catheter used for parenteral nutrition is presumed to have been the main source of this persistent infection.

Epidemiological modelling of risk factors of human papilloma virus in women with positive cytology in the county of Csongrád.

This study was carried out to determine the prevalence and risk factors of genital HPV infection in women diagnosed with non-negative cytology in Southeastern Hungary. Cervical samples were collected for cytology and HPV testing from women seen at gynaecological outpatient clinics and diagnosed with non-negative cytology. The observed overall average HPV infection rate was found to be 61%. A smoking habit was the only risk factor in the logistic regression analysis that related significantly to exposure to HPV infection. Thus, prevention strategies should focus on the regular clinical cytological screening of HPV-infected patients and on the reduction of smoking.

Vulnerability and risk evaluation of agricultural nitrogen pollution for Hungary's main aquifer using DRASTIC and GLEAMS models.

In recent years, the significant improvement in point source depuration technologies has highlighted problems regarding, in particular, phosphorus and nitrogen pollution of surface and groundwater caused by agricultural non-point (diffuse) sources (NPS). Therefore, there is an urgent need to determine the relationship between agriculture and chemical and ecological water quality. This is a worldwide problem, but it is particularly relevant in countries, such as Hungary, that have recently become members of the European Community. The Italian Foreign Ministry has financed the PECO (Eastern Europe Countries Project) projects, amongst which is the project that led to the present paper, aimed at agricultural sustainability in Hungary, from the point of view of NPS. Specifically, the aim of the present work has been to study nitrates in Hungary's main aquifer. This study compares a model showing aquifer intrinsic vulnerability to pollution (using the DRASTIC parameter method; Aller et al. [Aller, L., Truman, B., Leher, J.H., Petty, R.J., 1986. DRASTIC: A Standardized System for Evaluating Ground Water Pollution Potential Using Hydrogeologic Settings. US NTIS, Springfield, VA.]) with a field-scale model (GLEAMS; Knisel [Knisel, W.G. (Ed.), 1993. GLEAMS--Groudwater Leaching Effects of Agricultural Management Systems, Version 3.10. University of Georgia, Coastal Plain Experimental Station, Tifton, GA.]) developed to evaluate the effects of agricultural management systems within and through the plant root zone. Specifically, GLEAMS calculates nitrate nitrogen lost by runoff, sediment and leachate. Groundwater monitoring probes were constructed for the project to measure: (i) nitrate content in monitored wells; (ii) tritium (3H) hydrogen radioisotope, as a tool to estimate the recharge conditions of the shallow groundwater; (iii) nitrogen isotope ratio delta15N, since nitrogen of organic and inorganic origin can easily be distinguished. The results obtained are satisfactory, above all regarding the DRASTIC evaluation method, which is shown to satisfactorily explain both low and high aquifer vulnerability, and furthermore proves to be a good tool for zoning hydrogeological regions in terms of natural system susceptibility to pollution. The GLEAMS model, however, proves not to be immediately usable for predictions, above all due to the difficulty in finding sufficient data for the input parameters. It remains a good tool, but only after an accurate validation, for decision support systems, in the specific case to integrate intrinsic vulnerability, from DRASTIC (or similar methods), with land use nitrate loads from GLEAMS, or similar methods. The PECO project has proved a positive experience to highlight the fundamental points of a decision support system, aimed to mitigate the nitrate risk for groundwater coming from Hungarian agricultural areas.

High frequency intragenic recombination during macronuclear development in Tetrahymena thermophila restores the wild-type SerH1 gene.

Macronuclear development in ciliates is characterized by extensive rearrangement of genetic material, including sequence elimination, chromosome fragmentation and telomere addition. Intragenic recombination is a relatively rare, but evolutionarily important phenomenon occurring in mitosis and meiosis in a wide variety of organisms. Here, we show that high frequency intragenic recombination, on the order of 30%, occurs in the developing amitotic macronucleus of the ciliate Tetrahymena thermophila. Such recombination, occurring between two nonsense transition mutations separated by 726 nucleotides, reproducibly restores wild-type expression of the SerH1 surface protein gene, thus mimicking complementation in trans heterozygotes. Recombination must be considered a potentially important aspect of macronuclear development, producing gene combinations not present in the germinal micronucleus.

Sequence, codon usage and cysteine periodicity of the SerH1 gene and in the encoded surface protein of Tetrahymena thermophila.

The temperature-regulated SerH1 gene coding for an immunodominant surface glycoprotein (i-Ag H1) of Tetrahymena thermophila has been sequenced. The gene is reproducibly rearranged during macronuclear development and steady state mRNA levels are present at < 36 degrees C. The deduced i-Ag H1 amino acid (aa) sequence is rich in Ser, Thr and Cys, and contains three periods each consisting of 85 aa punctuated by eight Cys with the general formula, CX6CX17CX2CX18CX2CX11CX2CX19 (where X = any aa). Such Cys periodicity is common to ciliate i-Ag. Codon usage in Tt, Paramecium primaurelia and P. tetraurelia i-Ag encoding genes is similar, with approx. 80% A+T in the 3' position which is in marked contrast to the approx. 54% 3' A+T in other ciliate genes.

The detection of hepatitis C virus in South Hungary.

BACKGROUND: More than 100 million people are infected with hepatitis C virus (HCV) worldwide. The prevalence of HCV infection varies from country to country and the natural history of hepatitis C infection is not well understood. OBJECTIVES: The prevalence of anti-HCV positive blood donors in South Hungary was determined. Potential risk factors of HCV transmission were investigated and compared to anti-HCV-negative blood donors. Furthermore, the rate of anti-HCV positivity in children who had received one or more blood transfusions prior to the implementation of anti-HCV blood donor screening was evaluated. STUDY DESIGN: A total of 45719 blood donors and 120 children were tested for the presence of anti-HCV antibodies by second- and third-generation enzyme immunoassays. Positive results were confirmed by a recombinant immunoblot assay. Data on potential sources of HCV transmission were obtained by interviews. RESULTS: Among blood donors, the rate of confirmed HCV antibody-positives was 0.4% (195 of 45719 donors). Previous surgery, transfusion, more than three pregnancies, and tattoos were significantly correlated with confirmed anti-HCV positivity. Two of 120 children (1.7%) were confirmed anti-HCV positives. In both of them, serum HCV RNA could be detected. CONCLUSIONS: The prevalence of anti-HCV positive blood donors in South Hungary is low. Nosocomial infections and tattooing were found to be the most important risk factors for transmission of HCV. Because of the low prevalence of anti-HCV positive blood donors, only a small number of children, who received blood transfusions prior to the implementation of anti-HCV blood donor screening, are infected with HCV.

Bluetongue virus: production and study of viral antigen for serological diagnosis.

A soluble antigen, produced from the culture supernatant of VERO cells infected with bluetongue virus serotype 4 (BTV-S4) and concentrated by sequential ultrafiltration with membranes with cut-off values 10(3) and 25 x 10(3) NMWP, showed complete identity to standard antigens when compared by agar gel immunodiffusion (AGID) and SDS-PAGE profiles, revealing that the main protein component responsible for the AGID reaction has a molecular weight of about 60 kDa corresponding probably to the NS1 protein.

Quinone reductase (NQO1), a sensitive redox indicator, is increased in Alzheimer's disease.

NAD(P)H:quinone oxidoreductase 1 (NQO1), a redox-regulated flavoenzyme, plays a central role in monitoring cellular redox state. NQO1 acts to protect against oxidative stress induced by a variety of metabolic situations, including metabolism of quinones and other xenobiotics, by: (i) functioning as a two electron donor to provide a shunt that competes with the formation of reactive oxygen species; (ii) maintaining reduced coenzyme Q; and (iii) regulating the stress activated kinase pathway. In Alzheimer's disease, while there is abundant evidence for the involvement of oxidative stress, the cause or the consequences are largely unresolved. We suspected that increased NQO1 could signal a major shift in redox balance in Alzheimer's disease and, in this study, found that NQO1 is localized not only to neurofibrillary tangles but also the cytoplasm of hippocampal neurons. By marked contrast, there is very little NQO1 in the same neuronal populations in young and age-matched controls. This novel association of NQO1 further buttresses the nexus of oxidative stress, via free radicals, with selective neuronal vulnerability and also supports a fundamental abnormality in redox balance in Alzheimer's disease.

The frequency and the role of Chlamydia trachomatis infection in premature labor.

OBJECTIVE: The importance of Chlamydia trachomatis (C. tr.) infection in the etiology of premature labor was examined in a prospective, representative, multicenter study. METHOD: Specimens were collected from 6161 subjects in seven centers and examined by the Gen-Probe method. RESULTS: The infection rate was 5.74%. There were no significant correlations between low birth weight, premature rupture of the membranes, dysmaturity and C. tr. infection. In cases of threatening premature labor, the infection rate was significantly higher in C. tr.-positive patients. In the event of combined low birth weight and perinatal death, the maternal C. tr. infection rate was significantly higher than in normal pregnancies. C. tr.-positive patients treated with roxithromycin had term deliveries. A correlation between poor social circumstances and a high C. tr. infection rate could be proved. CONCLUSION: Cases with a poor obstetric history and/or socially high-risk patients should be screened for C. tr. infection, and in positive cases treatment is recommended.

Different electrophoretypes of human rotaviruses in Hungary.

Polyacrylamide gel electrophoresis of rotaviral double-stranded ribonucleic acid (RNA) extracted directly from faecal specimens collected in three different parts of Hungary was applied to characterize and distinguish 21 randomly selected viral isolates. This technique made it possible to define 7 different electrophoretypes. Of the isolates 11 exhibited an identical "long" electrophoretic migration pattern. "Short" RNA pattern was found in two cases, and one atypical rotavirus was also revealed. This is the first description of rotavirus RNA electrophoretypes in Hungary.

Burden of human rotavirus-associated hospitalizations in three geographic regions of Hungary.

Data on hospital admissions and laboratory reports were used to estimate the number of hospitalizations of children aged 14 y or less in three geographic regions of Hungary due to group A rotavirus infection. Between January 1993 and December 1996, 9182 hospitalizations for gastroenteritis occurred, of which 1946 (21%) were associated with rotavirus infection. Most (90%) of the rotavirus detections were among children aged 4 y or less. By extrapolation, an estimated 5000 rotavirus-related hospitalizations (8.4/1000 children aged 4 y or less/y) occurred in Hungary during the study period. Marked seasonality of rotavirus infections was observed, with a peak of incidence from December to February. Rotaviruses with "long" RNA electropherotypes predominated each year, but in 1995/1996 20% of electropherotypes in the Budapest area were "short". Effective surveillance is required for all children hospitalized for diarrhoea as part of a rotavirus immunization program in Hungary.

[Antibiotic therapy of infections in patients on dialysis]. / Antibiotická liecba infekcií u dialyzovaných pacientov.

The results obtained in treating infections in 53 patients involved in a chronic dialysis-transplantation program are reported. Higher susceptibility to infections and reduced immune functions were observed in dialyzed patients. The problem of the occurrence rate of individual infections was analyzed and infections of the respiratory system, particularly bronchopneumonia, were found to be predominant. No patient died of infection; in two patients the prescribed antibiotic of first choice had to be changed; positive clinical and laboratory effect was recorded in 51 of the 53 patients treated, and after change of the antibiotic in all the patients. Particular regimens of individual antibiotics in dialyzed patients are given along with the dialyzability of the drugs. The best results were obtained with ofloxacin and doxycycline of Czecho-Slovak make in monotherapy, in combined treatment gentamycin an amikacin with cefamezin or with cefotaxim proved to be most effective. Of the 45 pathogenic agents isolated, Staphylococcus aureus, Klebsiella spp, and Acinetobacter lwoffi, which have a good sensitivity to antibiotics, had the highest occurrence rates. (Tab. 4, Ref. 6.).

[Acute renal insufficiency after the administration of tetracycline and gentamycin]. / Akútna renálna insuficiencia po podávaní tetracyklínu a gentamicínu.

The clinical course of eight case reports of patients with acute renal failure after administration of nephrotoxic antibiotics--specially of tetracycline and gentamycin--is demonstrated. All patients were suffering on preexisting nephropathy, many of them in stage of chronic renal failure according to various etiopathogenesis. As concomitant factor inducing acute renal failure together with antibiotics are: elderly, hepatopathy, surgical interventions, administration of other nephrotoxic drugs. In 6 patients, where acute renal failure induced by nonreducted doses of antibiotics appeared, the treatment was successful, in five cases due to short term haemodialysis, once conservatively with diuretics and volume diuresis. Two patients died before the therapeutic measures and dialysis could be performed. Algorithms in diagnosis and treatment of chronic renal failure--patients where antibiotic treatment is necessary are discussed.

[Lymphogranuloma venereum]. / Lymphogranuloma venereum.

A young couple's case of Lymphogranuloma venereum was reviewed by the authors. They described the case's medical history and then they reviewed those tissue--cultural and immunological--methods which made sure the assumed diagnose by clinical and histological datas. The symptomless and painless wife's subclinically process was discovered. They called attention for that in spite of correct diagnose rareness the illness occurs more often. On the pathological process was influenced therapeutical by tetracyclin. We can treat successfully with tetracyclin the so called "blind-cured' cases. This situation made comfortable the diagnostics activity and it contributed to the wrong surface that the illness occurs rarely.

[Comparative studies in the diagnosis of Chlamydia trachomatis infections]. / Osszehasonlító vizsgálatok a Chlamydia trachomatis fertözések diagnosztikájában.

Comparative evaluation of different methods for diagnosis of chlamydial infections was carried out. During the culture of the bacteria cycloheximide treated McCoy cell line was used, and elementary and reticulate bodies were detected by monoclonal antibodies with immunofluorescent (IF) method. Chlamydia specific IgM and IgG antibodies were determined with ELISA using S. minnesota mR 595 lipopolysaccharide (LPS) as antigen and by indirect IF with C. trachomatis L2 antigen. According to the results the LPS-ELISA developed in their laboratory proved to be an applicable method for the serodiagnosis of chlamydial infections parallel with the culture method.

[Role of Chlamydia trachomatis in diseases of the urogenital system]. / A Chlamydia trachomatis jelentösége az urogenitális rendszer megbetegedéseiben.

The authors carried out 402 examinations to detect Chlamydia trachomatis. The agent was detected by serological methods. The cultivation and serological methods proved to give significant results. Doxycyclin and Eryc capsules were successful in the therapy. The great number of positive chlamydia cases suggest to focus attention on detecting the agent on the therapy and on the prevention of the spreading of infection.

[Potentials of screening for Chlamydia trachomatis in Hungary: cost-benefit analysis]. / A Chlamydia trachomatis-szúrés lehetósége Magyarországon--költség-haszon elemzés.

Untreated chlamydial infections of the genital tract may cause a wide range of serious complications, which could be prevented by screening. Cost-effectiveness analysis based on previously reported epidemiological study among pregnant women was carried out to develop and evaluate cost-effectiveness of age-based screening (women younger than 20 years old) for Chlamydia trachomatis in Hungary. Three kind of screening strategies were used: a) no screening, b) screening by using ELISA test and c) screening by amplified Gen-Probe diagnostic test. Young age and unmarried status were significant predictors of the chlamydial infection. Prevalence of chlamydial infection was 11.4% in the group of age younger then 20 years. Strategy b) was more cost-effective than neither testing nor treating. Strategy c) was less cost-effective than non screening, unless certain conditions were satisfied. If the cost of the diagnostic test were less or equal than 2,000 HUF or the prevalence of infection in women were greater than 17%, screening strategy c) would be more cost-effective than no screening. Although screening by using ELISA test was more cost-effective than screening by amplified Gen-Probe test, additionally 10,000 infected cases could be prevented using amplified Gen-Probe method for screening Chlamydia trachomatis.

[Unusual manifestations of Bartonella infections]. / Bartonella-infekciók szokatlan megjelenési formái.

The authors review the cases of two patients with an atypical form of cat scratch disease. The first case exhibited ileocoecal and hepatoportal lymphadenitis, and the second case the emerging symptoms of a non-specific granulomatous process in the middle third of the right forearm, which caused a differential-diagnostic problem. Establishment of a diagnosis was possible only on the basis of the disease process and the pathological, serological and histopathological pictures of the lymphatic glands after other causes of the lymphadenopathy had been excluded. Following two weeks of antibiotic treatment, the patients were free of complaints- and symptoms. Bartonella antibody tests were performed on 5 cats living in the neighbourhood of the patients with titer determinations too in 3 cases.