Search PubMedSearch

SEARCH · Search PubMed

Results for “Viral entry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

99 records · Page 6Linked to original sources

A 4-year longitudinal wastewater surveillance of five gastroenteritis viruses and the correlation with clinical cases in Alberta, Canada.

Viruses are common causes of acute gastroenteritis worldwide. They are detected in large quantities in raw sewage making them amenable to wastewater-based surveillance (WBS). To monitor the prevalence of gastroenteritis viruses in wastewater and assess their correlation with clinical cases, wastewater samples collected between July 2020 and June 2024 from 12 wastewater treatment plants across Alberta, Canada were analyzed for norovirus (NoV) GI & GII, rotavirus (RoV), adenovirus (AdV), sapovirus (SaV) and astrovirus (AsV). Among the 5726 wastewater samples tested, AdV (80.5%) had the highest detection rate followed by NoV GII (75.6%), SaV (63.2%), NoV GI (59.4%), RoV (42.2%) and AsV (20.2%). Winter and spring seasonality was found for NoV and RoV in both wastewater and clinical disease. Public health interventions especially in the 1st year of the COVID-19 pandemic had a significant impact on their burden with marked reduction in wastewater detected viruses and clinical cases. NoV showed a strong correlation between its level in wastewater and the number of clinical cases, while moderate correlation was observed for the other four viruses. Cross-correlation analysis showed that changes of viral RNA concentration in wastewater lagged behind reported gastroenteritis cases by approximately 6 days to 3 weeks. To our knowledge, this is the longest multi-region WBS study monitoring multiple gastroenteritis viruses spanning both COVID-19 pandemic and post-pandemic periods. The data obtained from this study supported WBS as a complementary tool to track population-based circulation of gastroenteritis viruses, providing actionable public health data.

Clinical cases

Characteristics and functions of a cell adhesion molecule PvCadN in Penaeus vannamei during WSSV infection.

Cell adhesion not only maintains the integrity of the organism, but also plays an important role in the immune system, which is involved in modulation in the interaction between host and virus. In this study, a novel cell adhesion molecule from Penaeus vannamei, designated as PvCadN, was investigated. It had the typical molecular characteristics of cadherin family, with multiple extracellular cadherin repeat domains, a transmembrane region, and a conserved β-catenin-binding motif. Pvcadn is expressed ubiquitously across all detected tissues, with the highest transcriptional level in gills. RNA interference-mediated silencing of pvcadn significantly impaired the adhesion ability of shrimp hemocytes. Upon WSSV infection, pvcadn showed a tissue-specific expression pattern, with upregulation in gills and downregulation in hemocytes. Knockdown of pvcadn markedly suppressed the transcription of WSSV immediate-early gene ie1 and replication of the viral genome in vivo, suggesting that PvCadN acted as a potential virus-associated molecule. Furthermore, it was found that PvCadN was regulated by Lvβ-catenin, a core molecule in the Wnt signaling pathway that functions in innate immunity, at the transcriptional and protein levels. Silencing of lvβ-catenin significantly downregulated pvcadn transcription, and Lvβ-catenin bound directly to the Cadherin C domain of PvCadN. In summary, the study revealed that PvCadN was a key cell adhesion molecule involved in WSSV infection, which was regulated by Lvβ-catenin. Our findings will provide fundamental data for further investigation into cadherin-mediated immune regulation in shrimp, and offer new insights for the prevention and control of WSSV.

Animals

Histidine Supplementation Stabilizes Hearing and Vision and Improves Growth in HARS1-Related Autosomal Recessive Disorder Associated With Usher-Like Symptoms.

Autosomal recessive HARS1-related disorder (originally described as Usher syndrome type 3B) caused by a homozygous Y454S variant in the histidyl-tRNA synthetase gene (HARS1) is characterized by progressive sensorineural hearing and vision loss and respiratory deterioration with risk for sudden death following febrile illnesses. In-vitro studies have previously shown that histidine can rescue a humanized yeast model for pathogenic HARS alleles. Fourteen children homozygous for HARS Y454S were treated with supplemental oral histidine (50 mg/kg BID) and monitored with bloodwork and physical, visual, and audiometry assessments during a 3-year clinical trial, then followed for more than 4 years on histidine in the post-trial period. Patient fibroblasts were assessed for response to histidine. Hearing and vision remained stable, and growth improved significantly. Children remained healthy, with no severe deteriorations despite exposure to bacterial and viral infections, including COVID-19. Gains in growth were maintained in the post-trial period on varying levels of histidine supplementation. Daily oral histidine supplementation in children with autosomal recessive HARS1-related disorder can ameliorate or slow the progression of disease and is safe, inexpensive, and well tolerated. This study adds to the growing list of autosomal recessive ARSopathies (aminoacyl-tRNA synthetase disorders) that are amenable to amino acid supplementation.

Humans

Pathogenic Variants in HEPACAM Alter Protein Localization and Interactome in Astrocytes of the Developing Mouse Cortex.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukodystrophy characterized by early-onset macrocephaly, white matter edema, seizures, and motor and cognitive decline. Approximately 25% of MLC patients carry HEPACAM pathogenic variants, many of which are dominant missense variants causing remitting MLC Type 2b. HEPACAM encodes hepatic and glial cell adhesion molecule (hepaCAM), also known as GlialCAM, an astrocyte-enriched transmembrane protein with important roles in astrocyte territory establishment, gap junction coupling, branching organization, synaptic function, and development of the gliovascular unit. The molecular mechanisms through which pathogenic variants in HEPACAM alter hepaCAM protein function in vivo and facilitate MLC pathogenesis during brain development remain largely unknown. Here, we used new viral tools and proximity-based proteomics to examine how three different dominant pathogenic variants alter hepaCAM subcellular localization and protein interactome in astrocytes of the developing mouse cortex. We found dramatic changes in hepaCAM distribution throughout the astrocyte, which were common to all mutants tested. We also observed significant changes in protein interactome between wild type and mutant hepaCAM, including decreased association with previously described hepaCAM-interacting proteins Connexin 43 and CLC-2. Moreover, we identified the epilepsy-associate potassium channel KCNQ2 as a novel hepaCAM interaction partner and found reduced association between KCNQ2 and pathogenic variants. Collectively, our data provide new insights into hepaCAM protein function in astrocytes during brain development, reveal altered protein dynamics of pathogenic variants, and provide a new resource to explore the molecular underpinnings of MLC pathogenesis.

Animals

Ruling out pediatric bacterial epididymo-orchitis with urinalysis - The case for minimizing unnecessary antibiotic prescription.

INTRODUCTION: Epididymo-orchitis in pediatric patients is predominantly non-bacterial, often stemming from viral or reactive etiologies. Despite guidelines recommending conservative management for non-bacterial cases, antibiotic overtreatment remains prevalent in the outpatient setting. We evaluated the diagnostic accuracy of urinalysis in ruling out bacterial infection to support antibiotic stewardship in this population. METHODS: We conducted a cross-sectional diagnostic accuracy study using electronic health records from a large health maintenance organization in Israel. The cohort included patients younger than 18 years with a diagnosis of epididymo-orchitis or clinically overlapping entities (acute scrotum, appendage torsion) who had paired urinalysis and urine culture results within one week of diagnosis. Logistic regression and ROC curve analysis were performed to assess the ability of urinalysis parameters to predict positive urine cultures. RESULTS: Of 682 eligible cases, confirmed bacterial infection was rare, occurring in only 17 patients (2.5%). Nitrite positivity was the strongest independent predictor of infection (OR 43.98; p < 0.001). A prediction model incorporating all urinalysis parameters yielded an area under the curve (AUC) of 0.825 and achieved a 97.7% classification accuracy for correctly predicting negative cultures. Despite the low prevalence of infection, antibiotics were prescribed in 237 cases (34.7%). Urinary anatomic abnormalities were significantly associated with culture positivity. CONCLUSIONS: Bacterial coinfection in pediatric epididymo-orchitis is uncommon. Urinalysis serves as a highly accurate screening tool to rule out bacterial etiology. A negative urinalysis supports withholding antibiotics in this setting, reserving treatment for children with positive markers or known anatomic abnormalities. This evidence-based approach This evidence-based approach has the potential to reduce unnecessary antibiotic exposure, however prospective studies are needed to validate these findings before broad implementation.

Humans

Transdermal 17&#x3b2;-Estradiol for the Treatment of COVID-19: Protocol of an Early Terminated Phase 2 Randomized Controlled Trial.

BACKGROUND: Early epidemiological studies suggested that pre- and postmenopausal women receiving estrogen therapy were less likely to develop severe disease or die from COVID-19 infection. Potential mechanisms include estrogen-mediated immunomodulation and 17&#x3b2;-estradiol-induced downregulation of angiotensin-converting enzyme type 2 (ACE2), the cellular receptor for SARS-CoV-2. OBJECTIVE: This study aimed to evaluate the feasibility, safety, and preliminary efficacy of transdermal 17&#x3b2;-estradiol as an adjunctive treatment for COVID-19 in men and postmenopausal women. METHODS: We designed and conducted a randomized controlled trial comparing 17&#x3b2;-estradiol transdermal gel plus standard care with standard care alone in adults with confirmed COVID-19. Initial ethics and funding approvals were obtained in March 2021. Owing to changes in the epidemiology of COVID-19 in Qatar and revisions to national quarantine policies, protocol amendments were required before recruitment commenced in February 2022. The treatment duration was reduced from 10 to 7 days due to changes in national quarantine guidelines. Recruitment and follow-up were conducted between February 2022 and June 2022. RESULTS: Recruitment was substantially lower than anticipated because widespread COVID-19 vaccination, declining disease severity, and revised national quarantine policies markedly reduced the number of eligible hospitalized patients. Consequently, the planned sample size was not achieved, and the study was terminated in June 2022. A total of 29 men with mild COVID-19 were enrolled, with 44.8% (n=13) randomized to standard care and 55.2% (n=16) to transdermal 17&#x3b2;-estradiol plus standard care. The intervention was well tolerated, with no adverse safety signals or thromboembolic events reported. CONCLUSIONS: Although the study was underpowered to assess efficacy because recruitment targets were not achieved, it showed that transdermal 17&#x3b2;-estradiol was well tolerated, with no major safety concerns among enrolled participants. The experience also provided important operational lessons for conducting clinical trials during rapidly evolving pandemics. Adequately powered studies are required to determine whether transdermal estrogen has therapeutic potential against COVID-19, other ACE2-mediated coronavirus infections, or potentially other severe viral illnesses.

Humans

Pre-clinical immunogenicity and safety evaluation of H2 strain Hepatitis A Inactivated Vaccine in rhesus macaques.

BACKGROUND: Hepatitis A is a viral infection of the liver that can cause mild to severe illness. Currently, two types of HAV vaccines are used worldwide, inactivated hepatitis A vaccines, which are used in most countries, and live attenuated vaccines (H2 and L-A-1 strain), which are mainly used in China. The major disadvantage of live attenuated virus to cause secondary infections among contacts and mutation shifts of the live vaccine strain. The H2 strain was selected for the development of an inactivated hepatitis A vaccine to further reduce biosafety risks. Rhesus macaques high genomic homology with humans and the incubation period after hepatitis A vaccination and human natural infections are similar. We use rhesus macaques to assess immunogenicity and safety of the H2 strain Hepatitis A Inactivated Vaccine. METHODS: The vaccine was assessed in rhesus macaques, divided into four groups (n&#x202f;=&#x202f;10 per group): the control group (adjuvant buffer; aluminum content 0.35&#x202f;mg/mL; 2&#x202f;mL per dose), the low-dose group (320EU, 0.5&#x202f;mL of 640EU/mL with aluminum content 0.35&#x202f;mg/mL), the medium-dose group (640EU, 1&#x202f;mL of 640EU/mL with aluminum content 0.35&#x202f;mg/mL), and the high-dose group (1280EU, 2&#x202f;mL of 640EU/mL with aluminum content 0.35&#x202f;mg/mL). Animals were injected intramuscularly at multiple sites in the hind limbs and received four inoculations at 4-week intervals. Test items including Clinical indicators, immunogenicity indicators and Histopathological examination. RESULTS: No abnormalities were observed in any group in terms of general clinical condition throughout the study period except for slight decreases in body temperature after immunization. Hematological parameters, serum biochemistry indices, and histopathological findings showed fluctuated to different degrees of fluctuation after immunization across all groups. Immunogenicity assessments showed that the inactivated hepatitis A vaccine (H2) induced both humoral and cellular immune responses effectively, and the levels of antibodies increased with certain dose- and time-response trends. CONCLUSION: The inactivated hepatitis A vaccine (H2 strain, human diploid cell) was safe and immunogenic in non-human primates. The results provide strong preclinical support for the further clinical development of this vaccine candidate.

Animals

Whole cell inactivated poly-bacterial preparation MV130 effect on nasal mucosal immunity and experimental human pneumococcal carriage: double-blind randomised controlled trial with controlled human infection model.

BACKGROUND: Bacterial mucosal immunotherapy has shown protection of children and adults from both viral and bacterial respiratory infections, offering the potential to reduce antimicrobial use, and hence also control antimicrobial resistance (AMR). Pneumococcal carriage of vaccine type Streptococcus pneumoniae remains high in Malawi despite infant conjugate vaccination and AMR is increasing. We compared nasal inflammation following sublingual bacterial immunotherapy including S. pneumoniae (MV130, Inmunotek, Spain) or placebo and determined the effect in an experimental human pneumococcal carriage model. METHODS: A double-blind, randomised, placebo-controlled trial in healthy adult volunteers was conducted at Queen Elizabeth Central Hospital in Blantyre, Malawi. Participants were randomly allocated to receive MV130 or placebo sublingually once daily for 42 days. Mucosal inflammation (neutrophil to T cell ratio, NTR) was measured in nasal micro-biopsies. Post-treatment, participants were challenged with 160,000 CFU/naris S. pneumoniae 6B (Spn6b). Experimental pneumococcal carriage rates post inoculation were compared between the two arms. All participants completing the study were included in the analysis. Prospective trial registration: PACTR202403820001276. FINDINGS: 107 participants were enrolled and randomised to MV130/placebo between May and December 2024. There were no serious adverse events, complete compliance was good (72%) and all adverse events were mild. 96 participants (53 male, 43 female) completed the study with 52 participants randomised to MV130 and 44 to placebo. There was no difference in mucosal inflammation (neutrophil to T cell ratio) at day 14 of the intervention MV130 NTR median = 0.737 (IQR 0.294, 2.059) and placebo NTR = 0.831 (IQR 0.450, 2.073), p = 0.64. Secondary analyses showed a rise in mucosal neutrophils after MV130 treatment and after experimental pneumococcal inoculation. There was no difference in nasal or serum anti-pneumococcal immunoglobulin or in experimental pneumococcal carriage proportion between MV130 (12/52, 23%) and placebo (10/44, 23%) groups (unadjusted risk ratio 1.02 (CI 0.49-2.12) p = 1.0). INTERPRETATION: MV130 induced non-specific mild neutrophil inflammation of the nasal mucosa but had no protective effect against experimental human pneumococcal carriage. FUNDING: Wellcome Trust.

Humans

Contact tracing for hepatitis C: perspectives of people with experience of substance use and hepatitis C on intervention acceptability.

INTRODUCTION: Chronic hepatitis C (HCV) is a major cause of cirrhosis and hepatocellular carcinoma. In the UK, the principal risk factor for HCV is injecting drug use. The introduction of direct acting anti-virals (DAA's) have transformed HCV care, with cure rates of over 95%. However, HCV is often asymptomatic, and reinfection is a concern. Modelling and real-life studies demonstrate the potential effectiveness of a contact tracing approach for finding people who have acquired HCV through injecting drug use. However, it is not used routinely in the UK. This qualitative study was undertaken to assess the acceptability of a contact tracing approach to identify people who have injected drugs with an index patient recently diagnosed with HCV. METHODS: Twelve people with lived or living experience of injecting drug use and an HCV diagnosis were interviewed using semi-structured interview topic guides. Participants were purposefully selected according to the inclusion criteria and to ensure there was an even spread of male and female participants. Sekhon's Theoretical Framework of Acceptability, incorporating seven components (affective attitude, burden, ethicality, intervention coherence, opportunity cost, perceived effectiveness, and self-efficacy) was used to analyse data from interview transcripts. RESULTS: A sample of 12 people who inject drugs in the UK indicated that a contact tracing approach was acceptable across two components of Sekhon's acceptability framework: affective attitude and ethicality. Participants broadly found the idea of tracing people who may be at risk of contracting HCV acceptable, and the approach aligned with their value systems. A contact tracing approach would help alleviate concerns about putting other people's lives at risk through HCV transmission and was seen as a 'sensible' way of finding people at risk. However, there were caveats to this acceptability. Contact tracing approaches delivered by mainstream health, or governmental organisations increased burden, opportunity costs and perceived effectiveness of a contact tracing approach for HCV, particularly within contexts of exclusion and criminalisation of people who inject drugs. Burden and opportunity costs were also affected by individual experiences and risks of violence, sexual violence and abuse. There was a lack of knowledge of contact tracing approaches amongst respondents, leading to a lack of intervention coherence and misunderstandings of what contact tracing was and how it would work. Trusted relationships with NGOs and HCV specialist nurses reduced burden and increased confidence and ability (self-efficacy) to engage with a contact tracing approach. CONCLUSION: People who inject drugs broadly perceive contact tracing as an acceptable method of finding people who are at risk of HCV. However, this acceptability is based on specific modes of delivery through trusted organisations. Findings further highlight the importance of naming and describing contact tracing approaches appropriately, as well as assessing and mitigating against potential risk to index patients, to increase self-efficacy and capacity to engage. Considering these findings, the potential for expanding existing contact tracing approaches should be explored to ensure the UK reaches and maintains its elimination targets.

Humans