129 research outputs found
The DEAD-box protein MEL-46 is required in the germ line of the nematode Caenorhabditis elegans
Background: In the hermaphrodite of the nematode Caenorhabditis elegans, the first germ cells differentiate as sperm. Later the germ line switches to the production of oocytes. This process requires the activity of a genetic regulatory network that includes among others the fem, fog and mog genes. The function of some of these genes is germline specific while others also act in somatic tissues. DEAD box proteins have been shown to be involved in the control of gene expression at different steps such as transcription and pre-mRNA processing.Results: We show that the Caenorhabditis elegans gene mel-46 (maternal effect lethal) encodes a DEAD box protein that is related to the mammalian DDX20/Gemin3/DP103 genes. mel-46 is expressed throughout development and mutations in mel-46 display defects at multiple developmental stages. Here we focus on the role of mel-46 in the hermaphrodite germ line. mel-46(yt5) mutant hermaphrodites are partially penetrant sterile and fully penetrant maternal effect lethal. The germ line of mutants shows variable defects in oogenesis. Further, mel-46(yt5) suppresses the complete feminization caused by mutations in fog-2 and fem-3, two genes that are at the top and the center, respectively, of the genetic germline sex determining cascade, but not fog-1 that is at the bottom of this cascade.Conclusion: The C. elegans gene mel-46 encodes a DEAD box protein that is required maternally for early embryogenesis and zygotically for postembryonic development. In the germ line, it is required for proper oogenesis. Although it interacts genetically with genes of the germline sex determination machinery its primary function appears to be in oocyte differentiation rather than sex determination
Role of the C. elegans U2 snRNP protein MOG-2 in sex determination, meiosis, and splice site selection
In Caenorhabditis elegans, germ cells develop as spermatids in the larva and as oocytes in the adult. Such fundamentally different gametes are produced through a fine-tuned balance between feminizing and masculinizing genes. For example, the switch to oogenesis requires repression of the fem-3 mRNA through the mog genes. Here we report on the cloning and characterization of the sex determination gene mog-2. MOG-2 is the worm homolog of spliceosomal protein U2A′. We found that MOG-2 is expressed in most nuclei of somatic and germ cells. In addition to its role in sex determination, mog-2 is required for meiosis. Moreover, MOG-2 binds to U2B″/RNP-3 in the absence of RNA. We also show that MOG-2 associates with the U2 snRNA in the absence of RNP-3. Therefore, we propose that MOG-2 is a bona fide component of the U2 snRNP. Albeit not being required for general pre-mRNA splicing, MOG-2 increases the splicing efficiency to a cryptic splice site that is located at the 5′ end of the exon
Prognostic value of the fibrosis-4 index in human immunodeficiency virus type-1 infected patients initiating antiretroviral therapy with or without hepatitis C virus
Objective: To evaluate the Fibrosis (FIB)-4 index as a predictor of major liver-related events (LRE) and liver-related death (LRD) in human immunodeficiency virus (HIV) type-1 patients initiating combination antiretroviral therapy (cART).
Design: Retrospective analysis of a prospective cohort study.
Setting: Italian HIV care centers participating to the ICONA Foundation cohort.
Participants: Treatment-naive patients enrolled in ICONA were selected who: initiated cART, had hepatitis C virus (HCV) serology results, were HBsAg negative, had an available FIB-4 index at cART start and during follow up.
Methods: Cox regression models were used to determine the association of FIB4 with the risk of major LRE (gastrointestinal bleeding, ascites, hepatic encephalopathy, hepato-renal syndrome or hepatocellular carcinoma) or LRD.
Results: Three-thousand four-hundred seventy-five patients were enrolled: 73.3% were males, 27.2% HCV seropositive. At baseline (time of cART initiation) their median age was 39 years, had a median CD4+ T cell count of 260 cells/uL, and median HIV RNA 4.9 log copies/mL, 65.9% had a FIB-4 <1.45, 26.4% 1.45–3.25 and 7.7% >3.25. Over a follow up of 18,662 person-years, 41 events were observed: 25 major LRE and 16 LRD (incidence rate, IR, 2.2 per 1,000 PYFU [95% confidence interval, CI 1.6–3.0]). IR was higher in HCV seropositives as compared to negatives (5.9 vs 0.5 per 1,000 PYFU). Higher baseline FIB-4 category as compared to <1.45 (FIB-4 1.45–3.25: HR 3.55, 95% CI 1.09–11.58; FIB-4 >3.25: HR 4.25, 1.21–14.92) and time-updated FIB-4 (FIB-4 1.45–3.25: HR 3.40, 1.02–11.40; FIB-4 >3.25: HR 21.24, 6.75–66.84) were independently predictive of major LRE/LRD, after adjusting for HIV- and HCV-related variables, alcohol consumption and type of cART.
Conclusions: The FIB-4 index at cART initiation, and its modification over time are risk factors for major LRE or LRD, independently of infection with HCV and could be used to monitor patients on cART
Access and response to direct antiviral agents (DAA) in HIV-HCV co-infected patients in Italy: Data from the Icona cohort
Background Real-life data on access and response to direct antiviral agents (DAA) in HIV-HCV coinfected individuals are lacking. Methods HCV viremic, HIV-positive patients from Icona and Hepaicona cohorts nave to DAA by January 2013 were included. Access and predictors of starting DAA were evaluated. Switches of antiretroviral drugs at starting DAA were described. We calculated sustained virological response (SVR12) in those reaching 12 weeks after end-of-treatment (EOT), and defined treatment failure (TF) as discontinuation of DAA before EOT or non-SVR12. Statistical analyses included Kaplan-Meier curves, univariable and multivariable analyses evaluating predictors of access to DAA and of treatment outcome (non-SVR and TF). Results 2,607 patients included. During a median follow-up of 38 (IQR:30-41) months, 920 (35.3%) patients started DAA. Eligibility for reimbursement was the strongest predictor to access to treatment: 761/1,090 (69.8%) eligible and 159/1,517 (10.5%) non-eligible to DAA reimbursement. Older age, HIV-RNA50 copies/mL were associated to faster DAA initiation, higher CD4 count and HCV-genotype 3 with delayed DAA initiation in those eligible to DAA reimbursement. Up to 28% of patients (36% of those on ritonavir-boosted protease inhibitors, PI/r) underwent antiretroviral (ART) modification at DAA initiation. 545/595 (91.6%) patients reaching EOT achieved SVR12. Overall, TF occurred in 61/606 patients (10.1%), with 11 discontinuing DAA before EOT. Suboptimal DAA was the only independent predictor of both non-SVR12 (AHR 2.52, 95%CI:1.24-5.12) and TF (AHR: 2.19; 95%CI:1.13-4.22). Conclusions Only 35.3% had access to HCV treatment. Despite excellent rates of SVR12 rates (91.6%), only 21% (545/2,607) of our HIV-HCV co-infected patients are cured. © 2017 d'Arminio Monforte et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Determinants of worse liver-related outcome according to HDV infection among HBsAg positive persons living with HIV: Data from the ICONA cohort
Objectives: We aimed to study hepatitis D virus (HDV) prevalence and risk of progression to severe liver-related events (SLRE) in HBsAg positive people living with HIV (PLWH) in Italy; role of HDV-RNA copy levels, HCV coinfection and nadir CD4 counts were also investigated.Methods: People living with HIV (PLWH) from Italian Foundation cohort Naive antiretrovirals (ICONA) with available HBsAg and HDV Ab were enrolled. HBsAg, HDV Ab, HDV-RNA and HDV genotypes were tested. Primary end-point: time from first HDV screening to Severe Liver Related Events (SLRE: decompensated cirrhosis, liver transplantation, HCC). Fine-grey regression models were used to evaluate the association of HDV Ab, HDV-RNA, HDV/HCV coinfection, CD4 nadir and outcome. Secondary end-points: time to SLRE or death; HDV Ab and HDV-RNA prevalence.Results: A total of 152/809 (18.8%) HBsAg positive PLWH showed HDV Ab reactivity; 63/93 (67.7%) were HDV-RNA positive. Being male, persons who inject drugs (PWID), HCV Ab positive, with FIB-4 > 3.25 were independent factors of HDV Ab positivity. In a median follow-up of 5 years, 37 PLWH (4.1% at 5-year) developed SLRE and 97 (12.0%) reached the SLRE or death end-point. HDV-RNA positive (independently from HDV-RNA copy level) PLWH had a 4.6-fold (95%CI 2.0-10.5) higher risk of SLRE than HDV negatives. PLWH positive for both HCV Ab and HDV Ab showed the highest independent risk of SLRE (ASHR: 11.9, 95%CI: 4.6-30.9 vs. HCV neg/HDV neg). Nadir CD4 < 200/mL was associated with SLRE (ASHR: 3.9, 95% 1.0-14.5).Conclusions: One-fifth of the HBsAg positive PLWH harbour HDV infection, and are at high risk of progression to advanced liver disease. HCV contributes to worse outcomes. This population needs urgently effective treatments
Advanced liver disease outcomes after hepatitis C eradication by human immunodeficiency virus infection in PITER cohort
Liver disease progression after Hepatitis C Virus (HCV) eradication following direct-acting antiviral (DAA) treatment in the real-life setting according to Human Immunodeficiency Virus (HIV) coinfection was evaluated
Real-life data on potential drug-druginteractions in patients with chronic hepatitis C viral infection undergoing antiviral therapy with interferon-free DAAs in the PITER Cohort Study
Background
There are few real-life data on the potential drug-drug interactions (DDIs) between anti-HCV direct-acting antivirals (DAAs) and the comedications used. Aim To assess the potential DDIs of DAAs in HCV-infected outpatients, according to the severity of liver disease and comedication used in a prospective multicentric study.
Methods
Data from patients in 15 clinical centers who had started a DAA regimen and were receiving comedications during March 2015 to March 2016 were prospectively evaluated. The DDIs for each regimen and comedication were assigned according to HepC Drug Interactions (www.hep-druginteractions.org)
Results
Of the 449 patients evaluated, 86 had mild liver disease and 363 had moderate-to-severe disease. The use of a single comedication was more frequent among patients with mild liver disease (p = 0.03), whereas utilization of more than three drugs among those with moderate- to-severe disease (p = 0.05). Of the 142 comedications used in 86 patients with mild disease, 27 (20%) may require dose adjustment/closer monitoring, none was contraindicated. Of the 322 comedications used in 363 patients with moderate-to-severe liver disease, 82 (25%) were classified with potential DDIs that required only monitoring and dose adjustments; 10 (3%) were contraindicated in severe liver disease. In patients with mild liver disease 30% (26/86) used at least one drug with a potential DDI whereas of the 363 patients with moderate-to-severe liver disease, 161 (44%) were at risk for one or more DDI.
Conclusions
Based on these results, we can estimate that 30 - 44% of patients undergoing DAA and taking comedications are at risk of a clinically significant DDI. This data indicates the need for increased awareness of potential DDI during DAA therapy, especially in patients with moderate- to-severe liver disease. For several drugs, the recommendation related to the DDI changes from "dose adjustment/closer monitoring", in mild to moderate liver disease, to "the use is contraindicated" in severe liver disease
Response to First-Line Ritonavir-Boosted Protease Inhibitors (PI/r)-Based Regimens in HIV Positive Patients Presenting to Care with Low CD4 Counts: Data from the Icona Foundation Cohort
Different Mi-2 Complexes for Various Developmental Functions in Caenorhabditis elegans
Biochemical purifications from mammalian cells and Xenopus oocytes revealed that vertebrate Mi-2 proteins reside in multisubunit NuRD (Nucleosome Remodeling and Deacetylase) complexes. Since all NuRD subunits are highly conserved in the genomes of C. elegans and Drosophila, it was suggested that NuRD complexes also exist in invertebrates. Recently, a novel dMec complex, composed of dMi-2 and dMEP-1 was identified in Drosophila. The genome of C. elegans encodes two highly homologous Mi-2 orthologues, LET-418 and CHD-3. Here we demonstrate that these proteins define at least three different protein complexes, two distinct NuRD complexes and one MEC complex. The two canonical NuRD complexes share the same core subunits HDA-1/HDAC, LIN-53/RbAp and LIN-40/MTA, but differ in their Mi-2 orthologues LET-418 or CHD-3. LET-418 but not CHD-3, interacts with the Krüppel-like protein MEP-1 in a distinct complex, the MEC complex. Based on microarrays analyses, we propose that MEC constitutes an important LET-418 containing regulatory complex during C. elegans embryonic and early larval development. It is required for the repression of germline potential in somatic cells and acts when blastomeres are still dividing and differentiating. The two NuRD complexes may not be important for the early development, but may act later during postembryonic development. Altogether, our data suggest a considerable complexity in the composition, the developmental function and the tissue-specificity of the different C. elegans Mi-2 complexes
How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons
COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice
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