High-temperature deep-level transient spectroscopy system for defect studies in wide-bandgap semiconductors.

Full investigation of deep defect states and impurities in wide-bandgap materials by employing commercial transient capacitance spectroscopy is a challenge, demanding very high temperatures. Therefore, a high-temperature deep-level transient spectroscopy (HT-DLTS) system was developed for measurements up to 1100 K. The upper limit of the temperature range allows for the study of deep defects and trap centers in the bandgap, deeper than previously reported by DLTS characterization in any material. Performance of the system was tested by carrying out measurements on the well-known intrinsic defects in n-type 4H-SiC in the temperature range 300-950 K. Experimental observations performed on 4H-SiC Schottky diodes were in good agreement with the literature. However, the DLTS measurements were restricted by the operation and quality of the electrodes.

New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector.

A new beam line for medium energy ion mass scattering (MEIS) has been designed and set up at the Ångström laboratory, Uppsala University, Sweden. This MEIS system is based on a time-of-flight (ToF) concept and the electronics for beam chopping relies on a 4 MHz function generator. Repetition rates can be varied between 1 MHz and 63 kHz and pulse widths below 1 ns are typically obtained by including beam bunching. A 6-axis goniometer is used at the target station. Scattering angle and energy of backscattered ions are extracted from a time-resolved and position-sensitive detector. Examples of the performance are given for three kinds of probing ions, (1)H(+), (4)He(+), and (11)B(+). Depth resolution is in the nanometer range and 1 and 2 nm thick Pt layers can easily be resolved. Mass resolution between nearby isotopes can be obtained as illustrated by Ga isotopes in GaAs. Taking advantage of the large size detector, a direct imaging (blocking pattern) of crystal channels are shown for hexagonal, 4H-SiC. The ToF-MEIS system described in this paper is intended for use in semiconductor and thin film areas. For example, depth profiling in the sub nanometer range for device development of contacts and dielectric interfaces. In addition to applied projects, fundamental studies of stopping cross sections in this medium energy range will also be conducted.

Guidelines for the laboratory diagnosis of genital herpes in eastern European countries.

These guidelines aim to provide comprehensive information about sexually transmitted herpes simplex virus (HSV) infection and its laboratory diagnosis in eastern European countries. They are primarily intended for professionals testing specimens from patients at a sexual healthcare clinic but may also be helpful for community-based screening programmes. In particular, the guidelines recommend: (i) either viral culture or validated and approved nucleic acid amplification tests (NAATs) as the tests of choice for symptomatic patients, which should be promoted for laboratory confirmation of HSV infection; (ii) if culture or NAATs are not available, antigen detection--a direct immunofluorescence test or enzyme immunoassay from samples from symptomatic patients--could be employed, but HSV type determination is of importance; (iii) only type-specific serology should be used for detecting asymptomatic individuals, testing pregnant women at risk of acquiring HSV infection close to delivery, men who have sex with men and people who are HIV positive; (iv) widespread screening for HSV antibodies should be discouraged; and (v) any non-validated diagnostic tests should be validated against a recommended, approved gold standard.

Gene expression profiling identifies STAT3 as a novel pathway for immunomodulation by cholera toxin adjuvant.

Earlier studies have reported on both proinflammatory and anti-inflammatory activities of cholera toxin (CT). As CT is a powerful adjuvant, we were interested in identifying genes with a possible involvement in these functions. A global gene expression analysis in mouse B cells showed that CT regulated <100 annotated genes, which encoded transcription factors, G proteins, cell-cycle regulators, and immunoregulating molecules. Interestingly, CT regulated the expression of the signal transducer and activator of transcription (STAT)3 gene and influenced the level and activation of both isoforms STAT3 alpha and STAT3 beta, in vitro in a B-cell line and in Peyer's patch (PP) B cells and in vivo in freshly isolated splenic B cells from CT-treated mice. This effect was cAMP dependent and was not seen with CTB. B cells pre-exposed to CT were significantly more susceptible to the activation of STAT3 by interleukin (IL)-6 and IL-10. This exerted a stronger inhibitory effect of IL-10 on lipopolysaccharide (LPS)-stimulated B-cell proliferation and cytokine production (IL-6). Moreover, IgG1 and IgA production induced by LPS and IL-10 were enhanced by the addition of CT to cultures of PP or splenic B cells. This is the first study to provide a molecular mechanism that can reconcile previous findings of proinflammatory and anti-inflammatory effects by CT adjuvant.

Guidelines for the laboratory diagnosis of trichomoniasis in East European countries.

The laboratory diagnosis of sexually transmitted infections in many Eastern European countries remains suboptimal. The main objective of the present evidence-based guidelines is to provide comprehensive information regarding the laboratory diagnosis of infections caused by Trichomonas vaginalis in East European countries. In particular, the present guidelines recommend: (i) to encourage examination of the wet mounts of vaginal exudates, instead of stained smears, at all clinical settings; (ii) nucleic acid amplification tests (NAATs) or culture could be employed if no trichomonads are detected on microscopic examination of the wet preparation and there is a strong indication of infection and (iii) the use of NAATs is encouraged in screening, using non-invasive specimens, or high volume testing situations. In the absence of internationally recognized commercial NAAT systems, tests developed in-house should be validated using obtainable international standards and quality assured strictly. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country.

Stoma-related complications and stoma size - a 2-year follow up.

AIM: The purpose of the study was to prospectively describe stoma configuration and evaluate stoma-related complications and their association with possible risk factors. METHOD: All elective patients (n = 180) operated on with a formation of colostomy, ileostomy or loop-ileostomy between 2003 and 2005 were included in the study. Follow up took place on the ward postoperatively and five times during 2 years after discharge. On these occasions the diameter and height of the stoma were recorded. Complications such as peristomal skin problems, necrosis, leakage caused by a low stoma, stenosis, granuloma formation, prolapse and peristomal hernia formation were evaluated. RESULTS: Most complications occurred 2 weeks after discharge; 53% of patients with colostomies, 79% with loop-ileostomies and 70% of patients with end-ileostomy had one or more complications. The most common complication was skin problems and it was most common in patients with end-ileostomies (60%) and loop-ileostomies (73%). Postoperatively at ward review, the most common complication was necrosis, which occurred in 20% of patients with a colostomy. Granuloma formation was most frequent in colostomies. Almost all patients with an end-ileostomy and loop-ileostomy with a height lower than 20 mm had leakage and skin problems as had half of the patients with a colostomy height lower than 5 mm. CONCLUSION: To prevent stoma-related complications, it is important to produce an adequate height of the stoma, with early and regular follow ups and adjustment of the appliance. To work closely in collaboration with the colorectal surgeons is of utmost important to provide feedback and in turn, to improve stoma outcome.

Variability in diagnosis of clue cells, lactobacillary grading and white blood cells in vaginal wet smears with conventional bright light and phase contrast microscopy.

OBJECTIVE: Study the reproducibility of wet smear interpretation of clue cells, lactobacillary grades and leukocyte dominance with conventional bright light and phase contrast microscopy. STUDY DESIGN: Sets of vaginal specimens were taken from unselected consecutive women attending an outpatient gynaecology clinic. Air-dried vaginal fluid on a microscope slide was rehydrated with isotonic saline before examination by six independent international investigators. Some investigators initially used a conventional bright light microscope, followed by phase contrast technique. RESULTS: Using phase contrast microscopy, an excellent inter-observer agreement was obtained among all investigators for clue cells detection (Kappa values from 0.69 to 0.94) and lactobacillary grades (Kappa 0.73-0.93). When conventional light microscopes were used, poor agreement was obtained for these criteria (Kappa index 0.37-0.72 and 0.80, respectively), but switching to phase contrast microscopy by the same investigators, improved Kappa to 0.83-0.85 and 0.88, respectively. The inter-observer agreement for estimation of the leukocyte/epithelial cell ratio (Kappa index 0.17-0.67) was poor, irrespective of the type of microscopy applied. Intra-observer agreement of clue cell detection and lactobacillary grading was also found to be excellent if phase contrast microscopy was used (Kappa 0.87-0.93), and poor with conventional bright light microscopy (Kappa 0.45-0.66). CONCLUSION: Clue cells and the lactobacillary grades are reliably identified by phase contrast microscopy in wet smears, with excellent intra- and inter-observer reproducibility agreement, and better than when simple bright light microscopy was used. Evaluation of leukocyte grading, on the other hand, was inconsistent among the different microscopists, irrespective of the type of microscope used. We propose to grade the leukocytes in a different way than searching for leukocyte dominance over epithelial cells, namely by counting them per high power field and per epithelial cell.

Guidelines for the laboratory diagnosis of Chlamydia trachomatis infections in East European countries.

The present guidelines aim to provide comprehensive information regarding the laboratory diagnosis of infections caused by Chlamydia trachomatis in East European countries. These recommendations contain important information for laboratory staff working with sexually transmitted infections (STIs) and/or STI-related issues. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country.

Guidelines for the laboratory diagnosis of syphilis in East European countries.

The present guidelines aim to provide comprehensive and precise information regarding the laboratory diagnosis of the sexually transmitted infection (STI) syphilis in East European countries. These recommendations contain important information for laboratory staff working with STIs and/or STI-related issues. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country.

Mailed urine samples are not an effective screening approach for Chlamydia trachomatis case finding among young men.

BACKGROUND: Frequency of testing is known to be low for sexually transmitted infections (STIs) in men aged 20-24 years. The use of mailed, home-obtained urine specimens could increase the uptake of young men and facilitate screening programmes for the detection of asymptomatic Chlamydia trachomatis. OBJECTIVE: The aim of the present study is to evaluate the home screening approach as a tool for recruitment of asymptomatic men for screening of genital C. trachomatis infections. METHODS: Men aged 19-24 years old (n = 1936) were invited to participate in home-based testing for genital C. trachomatis infection. Persons who agreed to be tested were provided with a testing kit. Self-collected first void urine was sent for testing to the microbiology laboratory. The test result was accessible on the study's web-page 1 week after testing. Individuals with a diagnosed infection were instructed to contact the venereal disease department. RESULTS: The response rate was 24% (462/1936). The responders' main reason for not participating was a feeling of being safe regarding STIs (87%; 159/182). The primary reason for this feeling of safety was that the responders were in a steady relationship (59%; 107/159). Having sex outside a steady relationship was reported by 36% (90/250) of the responders. The prevalence of C. trachomatis infection among the responders was 2.02% and the reported history of chlamydial infection was 36% (34/95). Out of the responders, 92% (229/249) were, to varying degrees, concerned about getting STIs; however, the majority (72%; 174/242) estimated the risk to be low. CONCLUSION: Home screening using web-based answer management is a feasible tool for STI screening, which lowers the threshold for people at risk. In this particular population, however, the response rate was too low to be routinely introduced.

Diagnosis of non-viral sexually transmitted infections in Lithuania and international recommendations.

The aim of this study is to evaluate the range, quality and availability of diagnostic services for non-viral sexually transmitted infections (STIs), i.e. C. trachomatis, N. gonorrhoeae, T. vaginalis and T. pallidum, in Lithuania from September 2002 to December 2003. Surveillance data describing the organisation and performance characteristics of non-viral STI diagnostic services in Lithuania were collected using a questionnaire and subsequent site-visits. International evidence-based recommendations for non-viral STI diagnosis were used to evaluate the quality of the STI diagnostics. There were 171 facilities providing non-viral STI diagnostic services for the 3.5 million inhabitants of Lithuania. However, only 6% (n=9) of the respondents (n=153) could provide a confirmatory diagnosis, in accordance with international recommendations, for the full minimum range of relevant non-viral STIs in Lithuania, i.e. C. trachomatis, N. gonorrhoeae, T. pallidum, and T. vaginalis. In addition, accessibility to STI diagnostic services differed significantly among the different counties in Lithuania. Several of the respondents analysed low numbers of samples each year, and overall the sampling size was extremely low, especially for C. trachomatis diagnostics. In Lithuania, optimisation of non-viral STI diagnostics as well as of epidemiological surveillance and management of STIs is crucial. It may be worth considering a decrease in the number of laboratories, with those remaining having the possibility of performing STI diagnostic services that are optimised, in concordance with international recommendations, standardised, and quality assured using systematic internal and external quality controls and systems. In addition, establishment of national inter-laboratory networks and reference centres for non-viral STIs is recommended.

Diagnosis of non-viral sexually transmitted infections in Lithuania and international recommendations.

The aim of this study is to evaluate the range, quality and availability of diagnostic services for non-viral sexually transmitted infections (STIs), i.e. C. trachomatis, N. gonorrhoeae, T. vaginalis and T. pallidum, in Lithuania from September 2002 to December 2003. Surveillance data describing the organisation and performance characteristics of non-viral STI diagnostic services in Lithuania were collected using a questionnaire and subsequent site-visits. International evidence-based recommendations for non-viral STI diagnosis were used to evaluate the quality of the STI diagnostics. There were 171 facilities providing non-viral STI diagnostic services for the 3.5 million inhabitants of Lithuania. However, only 6% (n=9) of the respondents (n=153) could provide a confirmatory diagnosis, in accordance with international recommendations, for the full minimum range of relevant non-viral STIs in Lithuania, i.e. C. trachomatis, N. gonorrhoeae, T. pallidum, and T. vaginalis. In addition, accessibility to STI diagnostic services differed significantly among the different counties in Lithuania. Several of the respondents analysed low numbers of samples each year, and overall the sampling size was extremely low, especially for C. trachomatis diagnostics. In Lithuania, optimisation of non-viral STI diagnostics as well as of epidemiological surveillance and management of STIs is crucial. It may be worth considering a decrease in the number of laboratories, with those remaining having the possibility of performing STI diagnostic services that are optimised, in concordance with international recommendations, standardised, and quality assured using systematic internal and external quality controls and systems. In addition, establishment of national inter-laboratory networks and reference centres for non-viral STIs is recommended.

Trimethylamine and trimethylamine oxide levels in normal women and women with bacterial vaginosis reflect a local metabolism in vaginal secretion as compared to urine.

The smell of rotten fish is one of the characteristics of bacterial vaginosis (BV), and is due to trimethylamine (TMA). Trimethylamine can be found in human urine, although most of it occurs as the nonvolatile oxide (TMAO) form. The fraction TMA/TMAO can be expected to be the same in different body fluids if no local production of TMA occurs. In women with BV, TMAO in the vaginal fluid is expected to be chemically reduced by the local bacterial flora to the much more odorous TMA. We have therefore studied the local vaginal production of TMA in vaginal secretion compared to the general TMA-TMAO metabolism that was measured in urine using gas chromatography. Both vaginal fluid and random urine samples were collected from women, with and without BV, attending a Swedish clinic for sexually transmitted diseases, and these samples were analyzed for TMA and TMAO. The results show that a local production of TMA occurs in the vagina that is not part of the general metabolism of TMA-TMAO.

Chlamydia trachomatis infections in eastern Europe: legal aspects, epidemiology, diagnosis, and treatment.

OBJECTIVES: Knowledge concerning genital Chlamydia trachomatis infections in eastern Europe is scarce. Data on the legal aspects, epidemiology, diagnosis, and treatment of the infection have never been collected, summarised, and presented to the international scientific community. The aim of this study was to present the current situation on the main aspects of chlamydial infections in the countries of eastern Europe. METHODS: Written questionnaires concerning legal aspects, epidemiology, diagnosis, and treatment of the infection were distributed among national STI operating administrators as well as researchers who had presented papers at earlier meetings of European chlamydia or STI societies. RESULTS: Most of the countries have not legalised reporting of chlamydial infections and in those who have done so, the quality of the reporting system is poor. Contact tracing is mostly done on a voluntary basis. Reported chlamydia incidence varies from 21 to 276 per 100000 inhabitants. The most commonly used diagnostic test remains the direct immunofluorescence test; however, some tendencies towards nucleic acid amplification are in evidence. Diagnostic services are paid for by the patient himself, while treatment in many countries is partially or completely covered by public insurance. CONCLUSIONS: This is the first report summarising data concerning the situation on C trachomatis infections in eastern Europe. The reporting system and diagnosis of C trachomatis infections remain suboptimal, which allows neither control of the epidemiological situation nor optimal treatment of the patients. The most urgent work currently necessary is the education of professionals and the general population.

Cervical, urine and vaginal specimens for detection of Chlamydia trachomatis by ligase chain reaction in women: a comparison.

Screening for Chlamydia trachomatis in women is generally done using only one specimen from each patient in order to minimize costs. In this study the aim was to compare the performances of vaginal, cervical and urinary specimens in a population of young women with sparse symptoms. During 1998, specimens from 1,001 women at the Departments of Venereology and Youth Health Care at the University Hospital of Uppsala, Sweden were examined by both ligase chain reaction and cell culture for detection of C. trachomatis. The samples from the cervix, vagina and urine were tested by ligase chain reaction, while specimens for cell culture were collected from the cervix and urethra. The prevalence of genital C. trachomatis infections was 5.1%. A single urine specimen had a sensitivity of 80.0%, while the sensitivity of a single vaginal specimen was 96.0%. The specificity was 100% for the urine specimens and 99.4% for the vaginal specimens. The sensitivity and specificity of a single cervical specimen was 92.0% and 99.6%, respectively. Although the urine ligase chain reaction seemed to have the lowest sensitivity of the compared specimens for testing of C. trachomatis infections in this population, the differences in sensitivity between urine, cervical and vaginal specimens were not statistically significant.

Silencing of the Epstein-Barr virus latent membrane protein 1 gene by the Max-Mad1-mSin3A modulator of chromatin structure.

The tumor-associated latent membrane protein 1 (LMP1) gene in the Epstein-Barr virus (EBV) genome is activated by EBV-encoded proteins and cellular factors that are part of general signal transduction pathways. As previously demonstrated, the proximal region of the LMP1 promoter regulatory sequence (LRS) contains a negative cis element with a major role in EBNA2-mediated regulation of LMP1 gene expression in B cells. Here, we show that this silencing activity overlaps with a transcriptional enhancer in an LRS sequence that contains an E-box-homologous motif. Mutation of the putative repressor binding site relieved the repression both in a promoter-proximal context and in a complete LRS context, indicating a functional role of the repressor. Gel retardation assays showed that members of the basic helix-loop-helix transcription factor family, including Max, Mad1, USF, E12, and E47, and the corepressor mSin3A bound to the E-box-containing sequence. The enhancer activity correlated with the binding of USF. Moreover, the activity of the LMP1 promoter in reporter constructs was upregulated by overexpression of USF1 and USF2a, and the transactivation was inhibited by the concurrent expression of Max and Mad1. This suggests that Max-Mad1-mediated anchorage of a multiprotein complex including mSin3A and histone deacetylases to the E-box site constitutes the basis for the repression. Removal of acetyl moieties from histones H3 and H4 should result in a chromatin structure that is inaccessible to transcription factors. Accordingly, inhibition of deacetylase activity with trichostatin A induced expression of the endogenous LMP1 gene in EBV-transformed cells.

Evaluation of an STD-prevention program for Swedish university students.

The authors evaluated a sexually transmitted disease (STD)-prevention program that combined a mass media campaign with peer education. The program was designed to increase Swedish university students' knowledge about STDs, improve attitudes toward condom use, and tell students where to get an STD checkup. Preintervention and postintervention postal questionnaires wer used with an intervention group and two types of control groups. Responses ranged from 32% to 67% for the randomly selected students and from 93% to 99% for classroom and clinic participants. The intervention was noticed by a majority of the students (85-98%) and discussed by 43% to 57%; more women than men observed and discussed the campaign. Knowledge about STDs, where to turn for STD checkups, and the intention of having an STD checkup increased. Attitudes toward condom use were equally positive before and after the intervention. Although it was successful in attracting attention and leading to discussion of STD prevention, the campaign did not encourage students to have an STD checkup.