Visualising single molecules of HIV-1 and miRNA nucleic acids

BackgroundThe scarcity of certain nucleic acid species and the small size of target sequences such as miRNA, impose a significant barrier to subcellular visualization and present a major challenge to cell biologists. Here, we offer a generic and highly sensitive visualization approach (oligo fluorescent in situ hybridization, O-FISH) that can be used to detect such nucleic acids using a single-oligonucleotide probe of 19–26 nucleotides in length.ResultsWe used O-FISH to visualize miR146a in human and avian cells. Furthermore, we reveal the sensitivity of O-FISH detection by using a HIV-1 model system to show that as little as 1–2 copies of nucleic acids can be detected in a single cell. We were able to discern newly synthesized viral cDNA and, moreover, observed that certain HIV RNA sequences are only transiently available for O-FISH detection.ConclusionsTaken together, these results suggest that the O-FISH method can potentially be used for in situ probing of, as few as, 1–2 copies of nucleic acid and, additionally, to visualize small RNA such as miRNA. We further propose that the O-FISH method could be extended to understand viral function by probing newly transcribed viral intermediates; and discern the localisation of nucleic acids of interest. Additionally, interrogating the conformation and structure of a particular nucleic acid in situ might also be possible, based on the accessibility of a target sequence

Disease activity, severity, and damage in the UK juvenile-onset systemic lupus erythematosus cohort

<p>Objective: The UK Juvenile-Onset Systemic Lupus Erythematosus (JSLE) Cohort Study is a multicenter collaborative network established with the aim of improving the understanding of juvenile SLE. The present study was undertaken to describe the clinical manifestations and disease course in patients with juvenile SLE from this large, national inception cohort.</p> <p>Methods: Detailed data on clinical phenotype were collected at baseline and at regular clinic reviews and annual followup assessments in 232 patients from 14 centers across the UK over 4.5 years. Patients with SLE were identified according to the American College of Rheumatology (ACR) SLE classification criteria. The present cohort comprised children with juvenile SLE (n = 198) whose diagnosis fulfilled ≥4 of the ACR criteria for SLE.</p> <p>Results: Among patients with juvenile SLE, the female:male sex distribution was 5.6:1 and the median age at diagnosis was 12.6 years (interquartile range 10.4–14.5 years). Male patients were younger than female patients (P < 0.01). Standardized ethnicity data demonstrated a greater risk of juvenile SLE in non-Caucasian UK patients (P > 0.05). Scores on the pediatric adaptation of the 2004 British Isles Lupus Assessment Group disease activity index demonstrated significantly increased frequencies of musculoskeletal (82%), renal (80%), hematologic (91%), immunologic (54%), and neurologic (26%) involvement among the patients over time. A large proportion of the patients (93%) were taking steroids and 24% of the patients required treatment with cyclophosphamide. Disease damage was common, with 28% of the patients having a Systemic Lupus International Collaborating Clinics/ACR damage score of ≥1.</p> <p>Conclusion: The data on these patients from the UK JSLE Cohort Study, comprising one of the largest national inception cohorts of patients with juvenile SLE to date, indicate that severe organ involvement and significant disease activity are primary characteristics in children with juvenile SLE. In addition, accumulation of disease-associated damage could be seen.</p&gt

Mucocutaneous manifestations in a UK national cohort of juvenile-onset systemic lupus erythematosus patients

Objective. To determine whether mucocutaneous manifestations are associated with major organ involvement in a UK national cohort of juvenile-onset SLE (JSLE) patients.<p></p> Methods. JSLE patients (n = 241) from 15 different centres whose diagnosis fulfilled four or more of the ACR criteria were divided into two groups: those with at least one ACR mucocutaneous criterion (ACR skin feature positive) and those without (ACR skin feature negative) at diagnosis. The relative frequency of skin involvement was described by the paediatric adaptation of the 2004 British Isles Lupus Assessment Group (pBILAG-2004) index.<p></p> Results. One hundred and seventy-nine patients (74%) had ACR-defined skin involvement with no significant demographic differences compared with those without. ACR skin feature negative patients showed greater haematological (84% vs 67%), renal (43% vs 26%) (P < 0.05) and neurological (16% vs 4%) involvement (P = 0.001). Forty-two per cent of ACR skin feature negative patients had skin involvement using pBILAG-2004, which included maculopapular rash (17%), non-scaring alopecia (15%), cutaneous vasculitis (12%) and RP (12%). ACR skin feature negative patients with moderate to severe skin involvement by pBILAG-2004 showed greater renal and haematological involvement at diagnosis and over the follow-up period (P < 0.05). Higher immunosuppressive drug use in the skin feature negative group was demonstrated.<p></p> Conclusion. Patients who fulfil the ACR criteria but without any of the mucocutaneous criteria at diagnosis have an increased risk of major organ involvement. The pBILAG-2004 index has shown that other skin lesions may go undetected using the ACR criteria alone, and these lesions show a strong correlation with disease severity and major organ involvement

Epidemiology and outcomes of hospital-acquired bloodstream infections in intensive care unit patients: the EUROBACT-2 international cohort study

Purpose In the critically ill, hospital-acquired bloodstream infections (HA-BSI) are associated with significant mortality. Granular data are required for optimizing management, and developing guidelines and clinical trials. Methods We carried out a prospective international cohort study of adult patients (≥ 18 years of age) with HA-BSI treated in intensive care units (ICUs) between June 2019 and February 2021. Results 2600 patients from 333 ICUs in 52 countries were included. 78% HA-BSI were ICU-acquired. Median Sequential Organ Failure Assessment (SOFA) score was 8 [IQR 5; 11] at HA-BSI diagnosis. Most frequent sources of infection included pneumonia (26.7%) and intravascular catheters (26.4%). Most frequent pathogens were Gram-negative bacteria (59.0%), predominantly Klebsiella spp. (27.9%), Acinetobacter spp. (20.3%), Escherichia coli (15.8%), and Pseudomonas spp. (14.3%). Carbapenem resistance was present in 37.8%, 84.6%, 7.4%, and 33.2%, respectively. Difficult-to-treat resistance (DTR) was present in 23.5% and pan-drug resistance in 1.5%. Antimicrobial therapy was deemed adequate within 24 h for 51.5%. Antimicrobial resistance was associated with longer delays to adequate antimicrobial therapy. Source control was needed in 52.5% but not achieved in 18.2%. Mortality was 37.1%, and only 16.1% had been discharged alive from hospital by day-28. Conclusions HA-BSI was frequently caused by Gram-negative, carbapenem-resistant and DTR pathogens. Antimicrobial resistance led to delays in adequate antimicrobial therapy. Mortality was high, and at day-28 only a minority of the patients were discharged alive from the hospital. Prevention of antimicrobial resistance and focusing on adequate antimicrobial therapy and source control are important to optimize patient management and outcomes