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693 result(s) for "Schmidt, Axel"
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Changes in the prevalence of self-reported sexually transmitted bacterial infections from 2010 and 2017 in two large European samples of men having sex with men–is it time to re-evaluate STI-screening as a control strategy?
Many European countries reported increased numbers of syphilis, gonorrhoea and chlamydia diagnoses among men who have sex with men (MSM) in recent years. Behaviour changes and increased testing are thought to drive these increases. In 2010 and 2017, two large online surveys for MSM in Europe (EMIS-2010, EMIS-2017) collected self-reported data on STI diagnoses in the previous 12 months, diagnostic procedures, STI symptoms when testing, number of sexual partners, and sexual behaviours such as condom use during the last intercourse with a non-steady partner in 46 European countries. Multivariate regression models were used to analyse factors associated with diagnoses of syphilis, gonorrhoea/chlamydia, and respective diagnoses classified as symptomatic and asymptomatic. If applicable, they included country-level screening rates. Questions on STI diagnoses and sexual behaviours were answered by 156,018 (2010) and 125,837 (2017) participants. Between 2010 and 2017, overall diagnoses with gonorrhoea/chlamydia and syphilis increased by 76% and 83% across countries. Increases were more pronounced for asymptomatic compared to symptomatic infections. The proportion of respondents screened and the frequency of screening grew considerably. Condomless anal intercourse with the last non-steady partner rose by 62%; self-reported partner numbers grew. Increased syphilis diagnoses were largely explained by behavioural changes (including more frequent screening). Gonorrhoea/chlamydia increases were mainly explained by more screening and a change in testing performance. A country variable representing the proportion of men screened for asymptomatic infection was positively associated with reporting symptomatic gonorrhoea/chlamydia, but not syphilis. The positive association of country-level screening rates with the proportion of symptomatic infections with gonorrhoea/chlamydia may indicate a paradoxical effect of screening on incidence of symptomatic infections. Treatment of asymptomatic men might render them more susceptible to new infections, while spontaneous clearance may result in reduced susceptibility. Before expanding screening programmes, evidence of the effects of screening and treatment is warranted.
Flavan-3-ols are an effective chemical defense against rust infection
Phenolic secondary metabolites are often thought to protect plants against attack by microbes, but their role in defense against pathogen infection in woody plants has not been investigated comprehensively. We studied the biosynthesis, occurrence, and antifungal activity of flavan-3-ols in black poplar (Populus nigra), which include both monomers, such as catechin, and oligomers, known as proanthocyanidins (PAs). We identified and biochemically characterized three leucoanthocyanidin reductases and two anthocyanidin reductases from P. nigra involved in catalyzing the last steps of flavan-3-ol biosynthesis, leading to the formation of catechin [2,3-trans-(+)-flavan-3-ol] and epicatechin [2,3-cis-(−)-flavan-3-ol], respectively. Poplar trees that were inoculated with the biotrophic rust fungus (Melampsora larici-populina) accumulated higher amounts of catechin and PAs than uninfected trees. The de novo-synthesized catechin and PAs in the rust-infected poplar leaves accumulated significantly at the site of fungal infection in the lower epidermis. In planta concentrations of these compounds strongly inhibited rust spore germination and reduced hyphal growth. Poplar genotypes with constitutively higher levels of catechin and PAs as well as hybrid aspen (Populus tremula × Populus alba) overexpressing the MYB134 transcription factor were more resistant to rust infection. Silencing PnMYB134, on the other hand, decreased flavan-3-ol biosynthesis and increased susceptibility to rust infection. Taken together, our data indicate that catechin and PAs are effective antifungal defenses in poplar against foliar rust infection.
Mechanical alignment for primary TKA may change both knee phenotype and joint line obliquity without influencing clinical outcomes: a study comparing restored and unrestored joint line obliquity
Purpose In total knee arthroplasty (TKA), knee phenotypes including joint line obliquity are of interest regarding surgical realignment strategies. The hypothesis of this study is that better clinical results, including decreased postoperative knee pain, will be observed for patients with a restored knee phenotype. Methods A retrospective analysis was performed on prospective data, including 1078 primary osteoarthritic knees in 936 patients. The male:female ratio was 780:298, mean age at surgery was 71.3 years ± 8.0. International Knee Society Scores and standardized long-leg radiographs (LLR) were collected preoperatively and at 2 years follow-up after TKA. Patients were categorized using the Coronal Plane Alignment of the Knee (CPAK) classification including the lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) measured on LLR by a single observer, allowing knee phenotypes to be categorized considering the arithmetic hip–knee–ankle (aHKA) angle (MPTA-LDFA) as measure of constitutional alignment, and joint line obliquity (JLO) (MPTA + LDFA). Clinical results were compared between patients with surgically restored preoperative constitutional knee phenotype to patients without restored constitutional knee phenotypes. Descriptive data analysis such as means, standard deviations and ranges were performed. T tests for independent samples were performed to compare group differences. Comparisons of categorical data were performed using the χ 2 test. Significance was set at p  < 0.05. Results A third of patients (33.4%) had constitutional knee varus with apex distal JLO. 63.5% of patients had preoperative apex distal JLO. Postoperatively, 57.8% of patients had a neutral HKA (− 2° to 2°) and a neutral JLO (− 3° and 3°), with only 18% of patients with restored constitutional knee phenotype. Of these patients, statistically less postoperative pain was observed in patients where apex distal JLO was restored compared to non-restored apex distal JLO (pain score 46.7 vs. 44.6; p  = 0.02) without clinical relevance. Other categories of restored JLO or arithmetic HKA angle were not associated with improved outcomes. Conclusion This study showed that performing mechanical alignment for primary TKA resulted in most cases in a change of the preoperative knee phenotype. These results emphasize the relevance of considering joint line obliquity to better understand preoperative knee deformity and better restore knee phenotypes with a more personalized realignment strategy to potentially improve TKA postoperative results. Level of evidence III.
Trouble with Bleeding: Risk Factors for Acute Hepatitis C among HIV-Positive Gay Men from Germany—A Case-Control Study
To identify risk factors for hepatitis C among HIV-positive men who have sex with men (MSM), focusing on potential sexual, nosocomial, and other non-sexual determinants. Outbreaks of hepatitis C virus (HCV) infections among HIV-positive MSM have been reported by clinicians in post-industrialized countries since 2000. The sexual acquisition of HCV by gay men who are HIV positive is not, however, fully understood. Between 2006 and 2008, a case-control study was embedded into a behavioural survey of MSM in Germany. Cases were HIV-positive and acutely HCV-co-infected, with no history of injection drug use. HIV-positive MSM without known HCV infection, matched for age group, served as controls. The HCV-serostatus of controls was assessed by serological testing of dried blood specimens. Univariable and multivariable regression analyses were used to identify factors independently associated with HCV-co-infection. 34 cases and 67 controls were included. Sex-associated rectal bleeding, receptive fisting and snorting cocaine/amphetamines, combined with group sex, were independently associated with case status. Among cases, surgical interventions overlapped with sex-associated rectal bleeding. Sexual practices leading to rectal bleeding, and snorting drugs in settings of increased HCV-prevalence are risk factors for acute hepatitis C. We suggest that sharing snorting equipment as well as sharing sexual partners might be modes of sexual transmission. Condoms and gloves may not provide adequate protection if they are contaminated with blood. Public health interventions for HIV-positive gay men should address the role of blood in sexual risk behaviour. Further research is needed into the interplay of proctosurgery and sex-associated rectal bleeding.
European Men-Who-Have-Sex-With-Men Internet Survey (EMIS-2017): Design and Methods
Men-who-have-sex-with-men (MSM) carry a disproportionate burden of sexually transmitted infections across Europe. Health planners require sexual health needs assessment data to respond appropriately. In addition, surveillance of risk and precaution behaviours in this population enables evaluative judgements of policy responses. The European MSM Internet Survey (EMIS-2017) aimed to repeat the pan-European online survey on male homosexual behaviour conducted in 2010, both to update information required to plan and monitor health promotion interventions and consolidate harmonisation of existing behavioural surveillance approaches. Our study team collaborated with more than 200 partners from academia, public health and civil society across 50 countries. Starting from our previous EMIS-2010 questionnaire, partners engaged in three rounds of iterative survey development and piloting until the final content was agreed. Transfer to an online survey application was followed by further pre-testing before translation into 32 additional languages, final testing and sign-off. The survey was available to complete online in 33 languages simultaneously from 18 October 2017 to 31 January 2018. Ten international MSM dating mobile apps were paid to send short promotional messages, and national partners promoted the survey via at least another 272 websites and social media accounts. Real-time monitoring of responses facilitated targeted advertising by country and recruitment source. Ultimately 144,305 cases were submitted of which 137,358 (95.2%) were eligible for inclusion. EMIS-2017 demonstrated the feasibility of multi-country online MSM surveying with public funding. Meaningful involvement of a large number of collaborators in the survey design and its execution ensured successful recruitment. Careful design, piloting and presentation ensured the survey was acceptable and had authority and perceived community benefit. Partners in 38 countries have already been supplied with a national database of 100 or more respondents for national analysis, while the study team has focussed on international comparisons among 137,358 respondents in 50 countries.
Isoprenyl diphosphate synthases
The highly diverse structures of all terpenes are synthesized from the five carbon precursors dimethylallyl diphosphate and a varying number of isopentenyl diphosphate units through 1’-4 alkylation reactions. These elongation reactions are catalyzed by isoprenyl diphosphate synthases (IDS). IDS are classified depending on the configuration of the ensuing double bond as trans-and cis-IDS. In addition, IDS are further stratified by the length of their prenyl diphosphate product. This review discusses analytical techniques for the determination of product length and the factors that control product length, with an emphasis on alternative mechanisms. With recent advances in analytics, multiple IDS of Arabidopsis thaliana have been recently reinvestigated and demonstrated to yield products of different lengths than originally reported, which is summarized here. As IDS dictate prenyl diphosphate length and thereby which class of terpenes is ultimately produced, another focus of this review is the impact that altering IDS expression has on terpenoid natural product accumulation. Finally, recent findings regarding the ability of a few IDS to not catalyze 1’-4 alkylation reactions, but instead produce irregular products, with unusual connectivity, or act as terpene synthases, are also discussed.
Latin American Internet Survey for Men who have Sex with Men (LAMIS-2018): Design, methods and implementation
Despite men-who-have-sex-with-men (MSM) from Latin America (LA) are still a vulnerable population for known health-related conditions and social problems, availability of comparable data across LA countries for assessment and monitoring purposes is limited. The objective of this article is to present the study design and the questionnaire of LAMIS-2018 (Latin America MSM Internet Survey), its recruitment strategy, rates and sources by country, and the lessons learned from its implementation. LAMIS-2018 was a cross-sectional, internet-based survey targeting MSM living in 18 LA countries (Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela) that gathered data about sexual behaviors, HIV/STI and viral hepatitis knowledge, prophylactic use of antiretrovirals, psychosocial health, and access to sexual health services. The survey went online for four months and was available in three languages (Spanish, Portuguese, and Dutch). Promotion was carried out using dating apps, websites, social networks, and by community-based and academic organizations of each participating country directly in gay venues and in their own premises. Overall, 64,655 MSM participated in LAMIS-2018. Dating apps and websites were the most important recruitment source in most countries, except for Honduras, Nicaragua, and Suriname, where community-based organizations recruited most of the participants. Beyond the LAMIS-2018 implementation description, we highlight the feasibility of such a study in this context, based on the collaboration between community-based and academic organizations to obtain a large sample of MSM in the region. LAMIS-2018 data will contribute to identify determinants of risk behaviors and prevention needs of vulnerable MSM populations in each country of the region.
Links between transactional sex and HIV/STI-risk and substance use among a large sample of European men who have sex with men
Background In Europe, the highest proportion of HIV diagnoses are in gay men and other men who have sex with men (MSM). Globally, HIV prevalence is particularly high among males who report selling sex, but rates among men who buy sex from other men are less clear. This study analyzed the association of transactional sex (TS) and HIV diagnosis, sexually transmitted infection (STI) diagnoses, and various drug use; and examined the variations in TS by payment direction. Methods We conducted a cross-sectional, non-randomized, observational study. This European MSM Internet Survey recruited MSM from 38 European countries. For descriptive purposes we stratified according to TS behavior (frequently selling sex, frequently buying sex, neither frequently selling nor buying sex in the previous 12 months), and we constructed separate multivariable logistic regression models to investigate whether engaging in TS accounted for some of the HIV- and STI diagnoses and drug use in this population. Results Of almost 161,000 sexually active MSM, 12.2% engaged in TS. The multivariable logistic regression results showed that relative to not frequently engaging in TS, frequently selling sex was independently associated with a higher odds of reporting diagnosed HIV (ever, adjusted odds ratio [aOR] 1.60, confidence interval [CI] 95% 1.39 to 1.85), bacterial STIs (past 12 months, aOR 1.75 CI 95% 1.54 to 2.00), using heroin or crack cocaine or injecting drugs (aOR 3.17, CI 95% 2.70 to 3.73), and using benzodiazepines (aOR 2.13, CI 95% 1.88 to 2.41). Compared to men not engaging in frequent TS, frequently buying sex was associated with a higher odds of using benzodiazepines (aOR 2.13, CI 95% 1.88 to 2.41). Conclusions MSM who frequently sell sex suffer greater sexual- and substance use risks than other MSM, but both men who frequently sell and those who buy sex are more likely to use benzodiazepines. MSM who sell sex to other men constitute an important at-risk population who must be offered targeted health services.
Tick-borne encephalitis (TBE) in Switzerland: does the prolongation of vaccine booster intervals result in an increased risk of breakthroughs?
Abstract Background In 2006, the Swiss Federal Office of Public Health (FOPH) decided recommending a prolongation of vaccine booster intervals after the third dose for the prevention of tick-borne encephalitis (TBE) from 3 to 10 years. Methods To ascertain whether this amendment resulted in an increased rate of vaccine breakthroughs, we conducted a retrospective analysis of surveillance data collected 2000–19 by mandatory reporting to the Swiss FOPH. Fractions of breakthroughs [with 95% confidence intervals (CIs)]—0–3 years vs >3–10 years after the third vaccination dose—were compared across time periods and age groups. Results Among 3205 notified TBE cases, known vaccination status was reported in 2562 (79.9%), including 103 patients with ≥3 vaccine doses (4.0%). Among those, there were 39 patients who had received the last dose within 3 years and 48 patients in the >3–10 years group. During the 2010–19 period in which the new booster strategy was implemented there were 23 and 38 breakthroughs, respectively, and the annual breakthrough rate was 7.7 (95% CI 5.0–11.7) cases during the first 3 years after the last dose, and 5.4 (95% CI 3.9–7.5) cases in following 7 years. We observed no significant trend of TBE breakthroughs with increasing age. Increasing numbers of TBE and of vaccine breakthroughs over time have been associated with spreading endemicity and higher vaccination coverage in Switzerland. Conclusions There is no indication that extended booster intervals resulted in an increased rate of breakthroughs, but there was a marked public health benefit with respect to increased acceptability of TBE immunization in the general population.
Reemergence of Clade IIb–Associated Mpox, Germany, July–December 2023
In July 2023, clade IIb-associated mpox reemerged in Germany at low levels, mainly affecting men who have sex with men. We report a representative case and phylogeny of available genome sequences. Our findings underscore the need for standardized surveillance and indication-based vaccination to limit transmission and help prevent endemicity.