Proof of infectivity of hepatitis E virus particles from the ejaculate of chronically infected patients.

Recently, hepatitis E virus (HEV, Paslahepevirus balayani) particles were detected for the first time in the ejaculate of two chronically infected patients. Since then, we have been able to detect HEV in ejaculate in five further patients, and thus in a total of seven out of nine (78%) chronically infected men (age 36-67 years, median 56 years). In five patients, the HEV RNA concentration was more than 100-fold higher compared to the serum, while in two patients, the viral load was more than 10-fold lower. However, it has remained unclear whether viral particles shed in the ejaculate were infectious, as a previous cell culture model had failed to demonstrate the infectivity. In the current study, we employed an optimized HEV cell culture system based on overconfluent PLC/PRF/5 cells to investigate the infectivity of HEV particles from ejaculate and other body fluids. With this approach, we were able to show for the first time that HEV particles in the ejaculate from several patients were infectious. HEV replicated to high viral loads of 1e9 HEV RNA copies per ml. This indicates that HEV-positive ejaculate could bear a risk of infection for sexual partners.

Is doxycycline post-exposure prophylaxis being utilised in Germany? Insights from an online survey among German men who have sex with men.

PURPOSE: Doxycycline post-exposure prophylaxis (Doxy-PEP) reduces the likelihood of Chlamydia and early syphilis by approximately two-thirds. Currently, data on the frequency of Doxy-PEP use in men who have sex with men (MSM) are limited. This study aimed to assess knowledge, attitude towards, and frequency of Doxy-PEP use among MSM in Germany. METHODS: We conducted a national online survey in Germany from summer to fall 2023, recruiting MSM and transgender women. Participants were invited to complete the online survey through social media, online dating platforms, and print media advertisements with active recruitment and poster advertising in private practices, tertiary outpatient clinics, and MSM community events in Germany. RESULTS: In total, 438 participants completed the survey and were included in the analysis, and 285 (65.1%) were living with the human immunodeficiency virus (HIV) or taking HIV-pre-exposure prophylaxis (PrEP). Overall, 170 participants (38.8%) had heard of Doxy-PEP, and 275 (62.8%) would consider taking it, but only 32 (7.3%) reported having ever taken Doxy-PEP. The most common reason for a negative attitude towards Doxy-PEP were apprehension about insufficient detailed information, and concerns about antibiotic resistance. Doxy-PEP users were more likely to be on HIV-PrEP, had a higher self-reported risk of bacterial sexually transmitted infections (STIs), and often had a history of bacterial STIs. CONCLUSION: The study demonstrated high awareness and strong interest in Doxy-PEP among MSM in Germany, most of whom were living with HIV or taking HIV-PrEP; however, the actual usage of Doxy-PEP remains low in the summer and fall of 2023.

Characteristics of reproductive tract infections caused by common pathogens among the outpatients of reproductive medicine center in Putian: retrospective study.

BACKGROUND: This study aims to explore the infection and age distribution of Ureaplasma urealyticum (UU), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Herpes simplex virus type II (HSV II) among the outpatients of Reproductive Medicine Center in Putian, Fujian Province to provide a clinical basis for the early diagnosis and treatment of various reproductive tract diseases and infertility in this region. METHODS: A total of 1736 samples of secretions and exfoliated cervical cells were collected from the outpatients of the Reproductive Medicine Center of the Affiliated Hospital of Putian University from December 2021 to April 2023. The infections of UU, CT, NG and HSVII were detected by real-time fluorescence polymerase chain reaction (PCR), and the infection statuses of the patients with different genders, ages and diagnoses were analysed. RESULTS: Among the 1736 patients, 611 were male and 1125 were female. The male patients had higher UU infection rate but lower HSV II infection rate than the female patients. No significant difference in CT and NG infection rates was observed between the genders. The CT infection rate gradually decreased with the increase in the age. The difference in UU, NG and HSV II infection rates among the different age groups was not statistically significant. For UU infection, the male infertile patients had the highest rate of 37.72% (172/456). Meanwhile, the differences in CT, NG and HSV II infection rates among the different diagnosis groups were not statistically significant. Among the male and female infertile patients, the CT infection rate was the highest in the 21-25 years of age group at 11.11% (2/18) and 9.47% (9/95), respectively. No statistically significant difference in UU, CT, NG and HSV II infection rates was observed among the different age groups of patients diagnosed in relation to the family planning guidance and between the male and female patients with other diagnoses results. CONCLUSIONS: This study showed that UU was the most frequently identified pathogen in infertile men in Putian, Fujian Province. The CT infection rate was the highest in people under 20 years old, and the infection showed a tendency toward young individuals. Therefore, the publicity of sexual health knowledge must be strengthened, and the prevention and treatment of venereal diseases among young and middle-aged people must be improved. Moreover, the pathogen infection is related to infertility to a certain extent, which is conducive to clinical diagnosis and treatment.

Evaluation of an emergency department opt-out provider-driven HIV and syphilis screening and linkage-to-care program.

OBJECTIVE: While the effectiveness of emergency departments (ED) in screening for HIV and syphilis is understood, less is known about dual screening programs. We aim to evaluate the impact of an opt-out provider-initiated HIV and syphilis program on screening, diagnosis, and linkage to care outcomes. METHODS: We performed a retrospective review of patients screened pre (2014-2017) and post (2017-2021) program implementation. Primary outcomes include HIV and syphilis screening, incidence of positive tests, and proportion of patients linked to care. Secondary outcomes included pre-exposure prophylaxis (PrEP) referral and successful linkage rates for HIV-negative syphilis-positive patients. RESULTS: Pre-implementation, 882 HIV tests were performed, of which 22 (2.49%) were new cases and 18 (81.82%) were linked to care; 754 syphilis tests were performed, of which 33 (4.38%) were active infections and 30 (90.91%) were treated. No eligible patients received PrEP referral. Post-implementation, 12,999 HIV tests were performed, of which 73 (0.56%) were new cases and 55 (75.34%) were linked to care; 10,885 syphilis tests were performed, of which 216 (1.98%) were active infections and 188 (87.04%) were treated. 25 (9.09%) eligible patients were referred for PrEP, and four (16.0%) attended their appointment. CONCLUSIONS: Post-implementation, there was a 1373.81% and 1343.63% increase in screening, and a 231.82% and 554.55% increase in positive cases of HIV and syphilis, respectively. Dual screening programs can be successfully implemented within the existing ED framework to increase screening and early detection for HIV and syphilis.

Attitudes toward an HPV vaccine for condyloma acuminata and willingness to undergo vaccination among STD clinic attendees in China: Focus on STI prevention with HPV vaccine.

BACKGROUND: Condyloma acuminata (CA) is a common, and recurrent sexually transmitted disease (STD) that greatly contributes to direct health care costs and has a substantial psychosocial impact. Human papillomavirus (HPV) vaccination (containing L1 protein for HPV types 6 and 11) effectively controls CA. OBJECTIVES: We investigated attitudes toward the HPV vaccine for CA and willingness to undergo vaccination among STD clinic attendees in China. METHODS: Attendees at STD clinics at two selected hospitals in Guangdong and Jiangsu Provinces from May to September 2017 were requested to complete a self-administered questionnaire for this cross-sectional study. RESULTS: The participants' median age was 28 years (IQR: 24.0-34.0), and the sex ratio was balanced; 63.5% were from Guangdong, 36.5% were from Jiangsu, and 44.5% had a history of CA. The vaccine acceptance rate was high among the participants (85.8%,235/274) to whom the HPV vaccine for CA was available, especially among those who had heard of CA (89.0%, AOR = 3.14, 95% CI: 1.29-7.63, p = 0.0114). 95 (34.7%) of 274 participants had a positive attitude toward the HPV vaccine for CA. STD clinic attendees who had heard of the connection between HPV and CA (AOR = 2.56, 95% CI: 1.31-5.00, p = 0.0060), had heard of the HPV vaccines or cervical cancer vaccines (AOR = 1.90, 95% CI: 1.02-3.54, p = 0.0444) and had ever proactively discussed CA or the vaccine with others (AOR = 1.95, 95% CI:1.00-3.79, p = 0.0488) had better attitudes toward the HPV vaccine for CA. Over half of the participants (52.5%) expected the price of the HPV vaccine for CA to be under $90. CONCLUSION: The acceptance of the HPV vaccine for CA was high among STD clinic attendees in China, and the participants' self-perceived knowledge of CA and HPV was associated with better attitudes toward the HPV vaccine for CA. Education to improve knowledge is vital for reducing vaccine hesitancy.

Consumption of Health-Related Videos and Human Papillomavirus Awareness: Cross-Sectional Analyses of a US National Survey and YouTube From the Urban-Rural Context.

BACKGROUND: Nearly 70% of Americans use the internet as their first source of information for health-related questions. Contemporary data on the consumption of web-based videos containing health information among American adults by urbanity or rurality is currently unavailable, and its link with health topic awareness, particularly for human papillomavirus (HPV), is not known. OBJECTIVE: We aim to describe trends and patterns in the consumption of health-related videos on social media from an urban-rural context, examine the association between exposure to health-related videos on social media and awareness of health topics (ie, HPV and HPV vaccine), and understand public interest in HPV-related video content through search terms and engagement analytics. METHODS: We conducted a cross-sectional analysis of the US Health Information National Trends Survey 6, a nationally representative survey that collects data from civilian, noninstitutionalized adults aged 18 years or older residing in the United States. Bivariable analyses were used to estimate the prevalence of consumption of health-related videos on social media among US adults overall and by urbanity or rurality. Multivariable logistic regression models were used to examine the association between the consumption of health-related videos and HPV awareness among urban and rural adults. To provide additional context on the public's interest in HPV-specific video content, we examined search volumes (quantitative) and related query searches (qualitative) for the terms "HPV" and "HPV vaccine" on YouTube. RESULTS: In 2022, 59.6% of US adults (152.3 million) consumed health-related videos on social media, an increase of nearly 100% from 2017 to 2022. Prevalence increased among adults living in both urban (from 31.4% in 2017 to 59.8% in 2022; P<.001) and rural (from 22.4% in 2017 to 58% in 2022; P<.001) regions. Within the urban and rural groups, consumption of health-related videos on social media was most prevalent among adults aged between 18 and 40 years and college graduates or higher-educated adults. Among both urban and rural groups, adults who consumed health-related videos had a significantly higher probability of being aware of HPV and the HPV vaccine compared with those who did not watch health videos on the internet. The term "HPV" was more frequently searched on YouTube compared with "HPV vaccine." Individuals were most commonly searching for videos that covered content about the HPV vaccine, HPV in males, and side effects of the HPV vaccine. CONCLUSIONS: The consumption of health-related videos on social media in the United States increased dramatically between 2017 and 2022. The rise was prominent among both urban and rural adults. Watching a health-related video on social media was associated with a greater probability of being aware of HPV and the HPV vaccine. Additional research on designing and developing social media strategies is needed to increase public awareness of health topics.

Studying the interaction of glycans with intact virions and virus-like particles by ligand-observed NMR spectroscopy.

Virus-glycan interactions play a crucial role in the infection process of many viruses. NMR spectroscopy has emerged as a powerful tool for studying these interactions at the molecular level. In this article, we review several published papers and reports that have highlighted the application of NMR spectroscopy in understanding the complex questions of how viruses engage with and bind to receptor glycans. The use of saturation transfer difference (STD) NMR spectroscopy has demonstrated itself as highly advantageous in investigating the interaction between glycans and intact virions or virus-like particles (VLPs). The broad NMR signal linewidth of virions and VLPs allows efficient saturation without affecting the glycan signals. The advantage of this approach is that the viral capsid environment in protein organization and function is not ignored and therefore provides a more biologically relevant model for exploring the interactions between the virus and the host cell glycans. We will review some examples of using NMR spectroscopy to study influenza cell tropism, rotaviruses, and noroviruses.

Differential Solvent DEEP-STD NMR and MD Simulations Enable the Determinants of the Molecular Recognition of Heparin Oligosaccharides by Antithrombin to Be Disentangled.

The interaction of heparin with antithrombin (AT) involves a specific sequence corresponding to the pentasaccharide GlcNAc/NS6S-GlcA-GlcNS3S6S-IdoA2S-GlcNS6S (AGA*IA). Recent studies have revealed that two AGA*IA-containing hexasaccharides, which differ in the sulfation degree of the iduronic acid unit, exhibit similar binding to AT, albeit with different affinities. However, the lack of experimental data concerning the molecular contacts between these ligands and the amino acids within the protein-binding site prevents a detailed description of the complexes. Differential epitope mapping (DEEP)-STD NMR, in combination with MD simulations, enables the experimental observation and comparison of two heparin pentasaccharides interacting with AT, revealing slightly different bound orientations and distinct affinities of both glycans for AT. We demonstrate the effectiveness of the differential solvent DEEP-STD NMR approach in determining the presence of polar residues in the recognition sites of glycosaminoglycan-binding proteins.

Saturation Transfer Difference NMR and Molecular Docking Interaction Study of Aralkyl-Thiodigalactosides as Potential Inhibitors of the Human-Galectin-3 Protein.

Human Galectin-3 (hGal-3) is a protein that selectively binds to ß-galactosides and holds diverse roles in both normal and pathological circumstances. Therefore, targeting hGal-3 has become a vibrant area of research in the pharmaceutical chemistry. As a step towards the development of novel hGal-3 inhibitors, we synthesized and investigated derivatives of thiodigalactoside (TDG) modified with different aromatic substituents. Specifically, we describe a high-yielding synthetic route of thiodigalactoside (TDG); an optimized procedure for the synthesis of the novel 3,3'-di-O-(quinoline-2-yl)methyl)-TDG and three other known, symmetric 3,3'-di-O-TDG derivatives ((naphthalene-2yl)methyl, benzyl, (7-methoxy-2H-1-benzopyran-2-on-4-yl)methyl). In the present study, using competition Saturation Transfer Difference (STD) NMR spectroscopy, we determined the dissociation constant (Kd) of the former three TDG derivatives produced to characterize the strength of the interaction with the target protein (hGal-3). Based on the Kd values determined, the (naphthalen-2-yl)methyl, the (quinolin-2-yl)methyl and the benzyl derivatives bind to hGal-3 94, 30 and 24 times more strongly than TDG. Then, we studied the binding modes of the derivatives in silico by molecular docking calculations. Docking poses similar to the canonical binding modes of well-known hGal-3 inhibitors have been found. However, additional binding forces, cation-π interactions between the arginine residues in the binding pocket of the protein and the aromatic groups of the ligands, have been established as significant features. Our results offer a molecular-level understanding of the varying affinities observed among the synthesized thiodigalactoside derivatives, which can be a key aspect in the future development of more effective ligands of hGal-3.

A systematic review and clinical atlas on mucocutaneous presentations of the current monkeypox outbreak: With a comprehensive approach to all dermatologic and nondermatologic aspects of the new and previous monkeypox outbreaks.

Monkeypox is a zoonotic disease, endemic in central and west African regions, and has re-emerged, currently causing an outbreak as of May 2022. In this systematic review, we aimed to characterize the current face of the disease, with a detailed categorization of mucocutaneous, as well as systemic symptoms of the disease. We searched four main online databases with the keywords "monkeypox" and "Orthopoxvirus". A total of 46 articles were included, with a cumulative number of 1984 confirmed cases. Patients were predominantly men who have sex with men, who were mostly in their 30s, with a history of unprotected sexual contact or international travel. Among mucocutaneous manifestations, anogenital lesions were the most commonly observed, followed by lesions on the limbs, face, trunk, and palms or soles. Among lesion types, vesiculopustular, pustular or pseudo-pustular, vesicular-umbilicated and papular lesions were the most common, mainly presenting asynchronously, with less than 10 lesions on each patient. Almost all patients also reported systemic manifestations, namely fever, lymphadenopathy, fatigue, myalgia, headaches, pharyngitis, and proctitis. Sexual contact is the main pathway of transmission in the current outbreak, with viral shedding in bodily fluids playing a key role. We've compared these idiosyncratic findings of the new outbreak with previous outbreaks. We've also gathered and categorized images from our included studies to make a "clinical atlas" for this "new" face of monkeypox, which can be of utmost importance for clinicians to be familiarized with, and have a clear picture of monkeypox for their differential diagnoses.

Toxicologic Pathology Forum: Opinion on Approaches for Reporting Toxic and Adverse Dose Levels in Nonclinical Toxicology Studies Supporting the Development of Anticancer Pharmaceuticals.

The advancement of an investigational new drug in humans is a significant developmental milestone. In first-in-human (FIH)-enabling toxicology studies, the highest dose without a test article-related adverse effect (no-observed-adverse-effect-level [NOAEL]) serves as the basis for deriving a safe FIH starting dose. For anticancer pharmaceuticals, the FIH dose may be calculated using the highest non-severely toxic dose (HNSTD) in nonrodent models or the dose severely toxic to 10% (STD10) in rodents. Given the practice of reporting the NOAEL, but the lack of regulatory requirements to do so for anticancer pharmaceuticals, we conducted an informal survey of 20 companies to answer the question "How is our industry reporting toxic/adverse dose levels in FIH-enabling toxicology studies for anticancer indications?" The data indicated 4 reporting approaches, each providing a path to regulatory acceptance. Within the integrated toxicology study report, 45% of respondents report the HNSTD/STD10, 25% report the NOAEL, 20% report both the HNSTD/STD10 and NOAEL, and 10% do not define either, reserving definitions for regulatory submissions. One reporting approach may be preferred over another for reasons including consistency across indications, repurposing pharmaceuticals, regulatory feedback, or simplicity. The reporting approach should be defined in advance of study initiation, and the pathologist should provide context to support the chosen approach.

HIV/STD prevalence and test uptake among african in Guangzhou, China: an analysis of data from hospital-based surveillance.

Human immunodeficiency virus (HIV) and sexually transmitted diseases (STDs) cause substantial morbidity and mortality both in African and China. However, there is limited data available on the prevalence of HIV/STDs and the uptake of testing experience ever during in China among African migrants. A venue-based survey was conducted at a tertiary hospital in Guangzhou to investigate the prevalence of HIV/STDs through laboratory testing and identify the associated factors. A total of 200 eligible participants completed the survey and bring into the analysis from April to October 2019, and the temporary visitors were excluded. The prevalence rates of HIV, syphilis, NG, CT, and HBsAg among the participants were 1.0%, 2.5%, 1.0%, 1.5%, and 5.5%, respectively. The overall reported rate of HIV/STD testing was 37.0%, with rates of 23.0% for HIV, 16.5% for syphilis, 12.5% for NG, 6.5% for genital herpes, 5.0% for condyloma acuminata, and 2.5% for CT. HIV/STD testing was associated with living environment in Guangzhou, having medical insurance in China, and utilizing health services in China in the past year. HIV/STDs are prevalent among Africans in Guangzhou, and the epidemic is likely to spread due to a significant proportion of unprotected sexual behaviors and low rates of HIV/STD testing. Urgent interventions, including targeted health education, promotion of health service utilization, and active surveillance of HIV/STDs, are needed to reduce the risk of HIV/STD transmission.

Multivalent calix[4]arene-based mannosylated dendrons as new FimH ligands and inhibitors.

We report the synthesis and biological characterization of a novel class of multivalent glycoconjugates as hit compounds for the design of new antiadhesive therapies against urogenital tract infections (UTIs) caused by uropathogenic E. coli strains (UPEC). The first step of UTIs is the molecular recognition of high mannose N-glycan expressed on the surface of urothelial cells by the bacterial lectin FimH, allowing the pathogen adhesion required for mammalian cell invasion. The inhibition of FimH-mediated interactions is thus a validated strategy for the treatment of UTIs. To this purpose, we designed and synthesized d-mannose multivalent dendrons supported on a calixarene core introducing a significant structural change from a previously described family of dendrimers bearing the same dendrons units on a flexible pentaerythritol scaffold core. The new molecular architecture increased the inhibitory potency against FimH-mediated adhesion processes by about 16 times, as assessed by yeast agglutination assay. Moreover, the direct molecular interaction of the new compounds with FimH protein was assessed by on-cell NMR experiments acquired in the presence of UPEC cells.

A hybrid approach reveals the allosteric regulation of GTP cyclohydrolase I.

Guanosine triphosphate (GTP) cyclohydrolase I (GCH1) catalyzes the conversion of GTP to dihydroneopterin triphosphate (H2NTP), the initiating step in the biosynthesis of tetrahydrobiopterin (BH4). Besides other roles, BH4 functions as cofactor in neurotransmitter biosynthesis. The BH4 biosynthetic pathway and GCH1 have been identified as promising targets to treat pain disorders in patients. The function of mammalian GCH1s is regulated by a metabolic sensing mechanism involving a regulator protein, GCH1 feedback regulatory protein (GFRP). GFRP binds to GCH1 to form inhibited or activated complexes dependent on availability of cofactor ligands, BH4 and phenylalanine, respectively. We determined high-resolution structures of human GCH1-GFRP complexes by cryoelectron microscopy (cryo-EM). Cryo-EM revealed structural flexibility of specific and relevant surface lining loops, which previously was not detected by X-ray crystallography due to crystal packing effects. Further, we studied allosteric regulation of isolated GCH1 by X-ray crystallography. Using the combined structural information, we are able to obtain a comprehensive picture of the mechanism of allosteric regulation. Local rearrangements in the allosteric pocket upon BH4 binding result in drastic changes in the quaternary structure of the enzyme, leading to a more compact, tense form of the inhibited protein, and translocate to the active site, leading to an open, more flexible structure of its surroundings. Inhibition of the enzymatic activity is not a result of hindrance of substrate binding, but rather a consequence of accelerated substrate binding kinetics as shown by saturation transfer difference NMR (STD-NMR) and site-directed mutagenesis. We propose a dissociation rate controlled mechanism of allosteric, noncompetitive inhibition.

Molecular Basis for the Selectivity of DHA and EPA in Sudlow's Drug Binding Sites in Human Serum Albumin with the Combined Use of NMR and Docking Calculations.

Medium- and long-chain saturated and unsaturated free fatty acids (FFAs) are known to bind to human serum albumin (HSA), the main plasma carrier protein. Atomic-level structural data regarding the binding mode in Sudlow's sites I (FA7) and II (FA4, FA3) of the polyunsaturated ω-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), however, are largely unknown. Herein, we report the combined use of saturation transfer difference (STD) and Interligand NOEs for Pharmacophore Mapping (INPHARMA) NMR techniques and molecular docking calculations to investigate the binding mode of DHA and EPA in Sudlow's sites Ι and ΙΙ of HSA. The docking calculations and the significant number of interligand NOEs between DHA and EPA and the drugs warfarin and ibuprofen, which are stereotypical ligands for Sudlow's sites I and II, respectively, were interpreted in terms of competitive binding modes and the presence of two orientations of DHA and EPA at the binding sites FA7 and FA4. The exceptional flexibility of the long-chain DHA and EPA and the formation of strongly folded structural motives are the key properties of HSA-PUFA complexes.

NMR and Docking Calculations Reveal Novel Atomistic Selectivity of a Synthetic High-Affinity Free Fatty Acid vs. Free Fatty Acids in Sudlow's Drug Binding Sites in Human Serum Albumin.

Saturation transfer difference (STD), inter-ligand NOEs (INPHARMA NMR), and docking calculations are reported for investigating specific binding sites of the high-affinity synthetic 7-nitrobenz-2-oxa-1,3-diazoyl-4-C12 fatty acid (NBD-C12 FA) with non-labeled human serum albumin (HSA) and in competition with the drugs warfarin and ibuprofen. A limited number of negative interligand NOEs between NBD-C12 FA and warfarin were interpreted in terms of a short-range allosteric competitive binding in the wide Sudlow's binding site II (FA7) of NBD-C12 FA with Ser-202, Lys-199, and Trp-214 and warfarin with Arg-218 and Arg-222. In contrast, the significant number of interligand NOEs between NBD-C12 FA and ibuprofen were interpreted in terms of a competitive binding mode in Sudlow's binding site I (FA3 and FA4) with Ser-342, Arg-348, Arg-485, Arg-410, and Tyr-411. NBD-C12 FA has the unique structural properties, compared to short-, medium-, and long-chain saturated and unsaturated natural free fatty acids, of interacting with well-defined structures with amino acids of both the internal and external polar anchor sites in Sudlow's binding site I and with amino acids in both FA3 and FA4 in Sudlow's binding site II. The NBD-C12 FA, therefore, interacts with novel structural characteristics in the drug binding sites I and II and can be regarded as a prototype molecule for drug development.

Factors affecting risk-taking behaviors among sexually active adolescents tested for HIV/STD.

OBJECTIVE: The purpose of this secondary data analysis was to identify potential contributors to high-risk sexual behaviors among sexually active adolescents who were tested for HIV and STDs compared to those who did not test for HIV and STDs. METHOD: Data from the 2019 Youth Risk Behavior Survey (YRBS) was used to explore potential predictors of risky behaviors among those tested for HIV/STD. A sample size of 3226 from the YRBS data base was used to explore predictors using Chi-square and logistic regressions analyses. RESULTS: Most adolescents reported not being tested for HIV (77.4%) and STD (83.9%). There were statistical differences between those tested for HIV and condom use, sexual intercourse before the age of 13 years, sexual intercourse with multiple people, and use of marijuana. Similar findings were found with adolescents tested for STDs. CONCLUSION: Findings of this study support the recommendations for a better understanding of the associations between drug use, early initiation of sexual activity, and condom use. Development of appropriate public health educational interventions can help decrease risky behaviors among these adolescents.

Mapping of Methyl Epitopes of a Peptide-Drug with Its Receptor by 2D STDD-Methyl TROSY NMR Spectroscopy.

The current trend in the biopharmaceutical market has boosted the development and production of biological drugs with high efficacy and fidelity for receptor binding. While high-resolution structural insights into binding epitopes of the receptor are indispensable for better therapeutic design, it is tedious and costly. In this work, we develop a protocol by integrating two well-known NMR-based solution-state methods. Saturation transfer double-difference with methyl-TROSY (STDD-Methyl TROSY NMR) was used to probe methyl binding epitopes of the ligand in a label-free environment. This study was carried out with Human insulin as a model peptide drug, with the insulin growth factor receptor (IGFR), which is an off-target receptor for insulin. Methyl epitopes identified from STDD-Methyl TROSY NMR spectroscopy were validated through the HADDOCK platform to generate a drug-receptor model. Since this method can be applied at natural abundance, it has the potential to screen a large set of peptide-drug interactions for optimum receptor binding. Thus, we propose STDD-Methyl TROSY NMR spectroscopy as a technique for rapid screening of biologics for the development of optimized biopharmaceutics.

Binding of Glycans to the SARS CoV-2 Spike Protein, an Open Question: NMR Data on Binding Site Localization, Affinity, and Selectivity.

We have used NMR experiments to explore the binding of selected glycans and glycomimetics to the SARS CoV-2 spike glycoprotein (S-protein) and to its receptor binding domain (RBD). STD NMR experiments confirm the binding of sialoglycans to the S-protein of the prototypic Wuhan strain virus and yield dissociation constants in the millimolar range. The absence of STD effects for sialoglycans in the presence of the Omicron/BA.1 S-protein reflects a loss of binding as a result of S-protein evolution. Likewise, no STD effects are observed for the deletion mutant Δ143-145 of the Wuhan S-protein, thus supporting localization of the binding site in the N-terminal domain (NTD). The glycomimetics Oseltamivir and Zanamivir bind weakly to the S-protein of both virus strains. Binding of blood group antigens to the Wuhan S-protein cannot be confirmed by STD NMR. Using 1 H,15 N TROSY HSQC-based chemical shift perturbation (CSP) experiments, we excluded binding of any of the ligands studied to the RBD of the Wuhan S-protein. Our results put reported data on glycan binding into perspective and shed new light on the potential role of glycan-binding to the S-protein.

Quantitative Evaluation of Noncovalent Interactions between 3,4-Dimethyl-1H-pyrazole and Dissolved Humic Substances by NMR Spectroscopy.

Nitrification inhibitors (NI) represent a valid chemical strategy to retard nitrogen oxidation in soil and limit nitrate leaching or nitrogen oxide emission. We hypothesized that humic substances can complex NI, thus affecting their activity, mobility, and persistence in soil. Therefore, we focused on 3,4-dimethylpyrazole phosphate (DMPP) by placing it in contact with increasing concentrations of model fulvic (FA) and humic (HA) acids. The complex formation was assessed through advanced and composite NMR techniques (chemical shift drift, line-broadening effect, relaxation times, saturation transfer difference (STD), and diffusion ordered spectroscopy (DOSY)). Our results showed that both humic substances interacted with DMPP, with HA exhibiting a significantly greater affinity than FA. STD emphasized the pivotal role of the aromatic signal, for HA-DMPP association, and both alkyl methyl groups, for FA-DMPP association. The fractions of complexed DMPP were determined on the basis of self-diffusion coefficients, which were then exploited to calculate both the humo-complex affinity constants and the free Gibbs energy (Kd and ΔG for HA were 0.5169 M and -1636 kJ mol-1, respectively). We concluded that DMPP-based NI efficiency may be altered by soil organic matter, characterized by a pronounced hydrophobic nature. This is relevant to improve nitrogen management and lower its environmental impact.