Modelling treatment-response rates.
Ontology highlight
ABSTRACT:
SUBMITTER: Grassberger C
PROVIDER: S-EPMC8682812 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Hepatitis C virus (HCV) antiviral treatment for people who inject drugs (PWID) could prevent onwards transmission and reduce chronic prevalence. We assessed current PWID treatment rates in seven UK settings and projected the potential impact of current and scaled-up treatment on HCV chronic prevalence. Data on number of PWID treated and sustained viral response rates (SVR) were collected from seven UK settings: Bristol (37-48% HCV chronic prevalence among PWID), East London (37-48%), Manchester (48-56%), Nottingham (37-44%), Plymouth (30-37%), Dundee (20-27%) and North Wales (27-33%). A model of HCV transmission among PWID projected the 10-year impact of (i) current treatment rates and SVR (ii) scale-up with interferon-free direct acting antivirals (IFN-free DAAs) with 90% SVR. Treatment rates varied from <5 to over 25 per 1000 PWID. Pooled intention-to-treat SVR for PWID were 45% genotypes 1/4 [95%CI 33-57%] and 61% genotypes 2/3 [95%CI 47-76%]. Projections of chronic HCV prevalence among PWID after 10 years of current levels of treatment overlapped substantially with current HCV prevalence estimates. Scaling-up treatment to 26/1000 PWID annually (achieved already in two sites) with IFN-free DAAs could achieve an observable absolute reduction in HCV chronic prevalence of at least 15% among PWID in all sites and greater than a halving in chronic HCV in Plymouth, Dundee and North Wales within a decade. Current treatment rates among PWID are unlikely to achieve observable reductions in HCV chronic prevalence over the next 10 years. Achievable scale-up, however, could lead to substantial reductions in HCV chronic prevalence.
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2022-05-05 | PXD010889 | Pride
Project description:High prices of direct acting antivirals (DAAs) for hepatitis C virus (HCV) can lead to restrictions on access to treatment in high- and middle-income countries. An increasing number of people in these countries are treating their HCV infection with generic drugs produced in India, China, Bangladesh or Egypt. This analysis assessed the efficacy of generic imported DAAs.Patients sourced generic versions of sofosbuvir (SOF), ledipasvir (LDV) and daclatasvir (DCV) from suppliers in India, Bangladesh, China and Egypt via three buyers' clubs. The choice of DAAs and the length of treatment were determined on baseline RNA levels, HCV genotype and stage of fibrosis. Patient HCV RNA levels were evaluated pre-treatment, during treatment, at end of treatment (EOT) and then for sustained virological response (SVR) at 4, 12, and 24 weeks, normally by a treating clinician.Overall 616 patients submitted results: 199 from an Australian buyers' club, 205 from a South-east Asian buyers' clubs, and 212 from an Eastern European buyers' club. Of the 616 patients treated, 276 received SOF/LDV (35 with ribavirin [RBV]) and 340 received SOF/DCV (61 with RBV). At baseline, 61% were male, 52% had HCV genotype 1 and 11% had liver cirrhosis. The mean age was 44.3 years and the mean baseline HCV RNA was 6.9 log10 IU/mL. A rapid virological response (RVR) was observed in 314/375 (84%) of the patients treated. Based on currently available data, the percentage of patients with HCV RNA below the lower limit of quantification (LLoQ) was 99% (234/237) at EOT, 99% (299/303) at SVR4 and 99% (247/250) at SVR12.In this analysis, treatment with imported generic DAAs achieved high rates of HCV RNA undetectability at the end of treatment, and SVR12 in 99% of patients evaluated to date. Mass treatment with generic DAAs is a feasible and economical alternative route of accessing curative DAAs, where the high prices for branded alternatives prevent access to treatment.
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Project description:IntroductionVibration perception threshold (VPT) examination using a neurothesiometer provides objective, sensitive and specific information, and has been utilized mainly in patients with diabetic polyneropathy.ObjectivesExplore the utility of VPT examination in CIDP patients.MethodsCIDP subjects attending the Neuromuscular clinic between 01/2013 and 12/2014 were evaluated. Demographic data, clinical history, physical examination, VPT values, and electrophysiologic data from their charts were extracted.Results70 charts were reviewed. 55 CIDP patients had elevated VPT, associated with higher frequency of abnormal sensory testing for various modalities (92.7% vs. 46.7%, p<0.0001), lower sensory and motor amplitudes and reduced conduction velocities on nerve conduction studies, and lower treatment response rates (54% vs. 93%, p = 0.01).ConclusionVPT examination is a simple tool, which is a reliable and sensitive measure not only for diabetic neuropathy, but also for CIDP. Moreover, in CIDP, elevated VPT values are also associated with lower treatment response rates.
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Project description:The development of transcriptomic tools has allowed exhaustive description of stress responses. These responses always superimpose a general response associated to growth rate decrease and a specific one corresponding to the stress. The exclusive growth rate response can be achieved through chemostat cultivation, enabling all parameters to remain constant except the growth rate. We analysed metabolic and transcriptomic responses of Lactococcus lactis in continuous cultures at different growth rates ranging from 0.09 to 0.47 h-1. Growth rate was conditioned by isoleucine supply. Although the metabolism was constant and homolactic, a widespread transcriptomic response involving 30 % of the genome was observed. The expression of genes encoding physiological functions associated with biogenesis increased with growth rate (transcription, translation, fatty acid and phospholipids metabolism). Many phages, prophages and transposons related genes were down regulated by growth rate suggesting genome plasticity to be involved in the adaptation to slow growth. The growth rate response was compared to carbon and amino-acid starvation transcriptomic responses, revealing constant and significant involvement of growth rate regulations in these two stressful conditions (overlap 26%). Although stringent response mechanism is considered as the one governing growth deceleration in bacteria, the rigorous comparison of the two transcriptomic responses clearly indicated the mechanisms are distinct. Moreover it was established that genes positively regulated by growth rate are preferentially located in the vicinity of replication origin while those negatively regulated are mainly encountered at the opposite. This result demonstrates the often neglected relationship between genes expression and their location on chromosome. Keywords: growth rate impact, continuous cultures
2009-04-28 | GSE10256 | GEO
Project description:The treatment of cancer using targeted radionuclide therapy is of interest to nuclear medicine and radiation oncology because of its potential for killing tumor cells while minimizing dose-limiting toxicities to normal tissue. The ionizing radiations emitted by radiopharmaceuticals deliver radiation absorbed doses over protracted periods of time with continuously varying dose rates. As targeted radionuclide therapy becomes a more prominent part of cancer therapy, accurate models for estimating the biologically effective dose (BED) or equieffective dose (EQD2?/?) will become essential for treatment planning. This study examines the radiobiological impact of the dose rate increase half-time during the uptake phase of the radiopharmaceutical. MDA-MB-231 human breast cancer cells and V79 Chinese hamster lung fibroblasts were irradiated chronically with 662 keV ? rays delivered with time-varying dose rates that are clinically relevant. The temporal dose-rate patterns were: 1. acute, 2. exponential decrease with a half-time of 64 h (Td = 64 h), 3. initial exponential increase to a maximum (half time Ti = 2, 8 or 24 h) followed by exponential decrease (Td = 64 h). Cell survival assays were conducted and surviving fractions were determined. There was a marked reduction in biological effect when Ti was increased. Cell survival data were tested against existing dose-response models to assess their capacity to predict response. Currently accepted models that are used in radiation oncology overestimated BED and EQD2?/? at low-dose rates and underestimated them at high-dose rates. This appears to be caused by an adaptive response arising as a consequence of the initial low-dose-rate phase of exposure. An adaptive response function was derived that yields more accurate BED and EQD2?/? values over the spectrum of dose rates and absorbed doses delivered. Our experimental data demonstrate a marked increase in cell survival when the dose-rate-increase half-time is increased, thereby suggesting an adaptive response arising as a consequence of this phase of exposure. We have modified conventional radiobiological models used in the clinic for brachytherapy and external beams of radiation to account for this phenomenon and facilitate their use for treatment planning in targeted radionuclide therapy.
| S-EPMC5669265 | biostudies-literature
Project description:Recent studies have suggested a negative impact of hepatocellular carcinoma (HCC) on sustained virologic response (SVR) to hepatitis C virus (HCV) direct acting antivirals (DAAs). We compared the effectiveness of DAAs in patients with cirrhosis, with and without HCC, and in those with HCC partially treated or untreated (PT/UT-HCC) versus completely treated (CT-HCC). HCC status was based on imaging 6 months before or 2 months after start of DAA therapy. Absence and presence of enhancing lesions after HCC treatment defined CT-HCC and PT/UT-HCC, respectively. Using minimally adjusted logistic regression, the association between the presence of HCC and SVR rates was estimated. Among the 1,457 patients with cirrhosis from HCV-TARGET with complete virologic data (per-protocol population) who did not undergo liver transplantation during treatment and followup, 1,300 were without HCC, 91 with CT-HCC, and 66 with PT/UT-HCC. Most patients were genotype 1 (81%) and treatment-experienced (56%), 41% had history of prior decompensation, and the median pretreatment Model for End-Stage Liver Disease was 9 (range 6-39). The SVR rates were 91% for patients without HCC, 84% for CT-HCC, and 80% for PT/UT-HCC. The presence of HCC (versus not having HCC) was associated with significantly lower odds of achieving SVR (odds ratio [OR] = 0.51, 95% confidence interval [CI]: 0.33-0.81; P = 0.003). However, among those with HCC, HCC treatment status (PT/UT-HCC versus CT-HCC) did not show association with SVR (OR = 0.79, 95% CI: 0.35-1.79, P = 0.569). Conclusions: The presence of HCC reduces the likelihood of SVR by 50%, but with no evident difference in those with completely treated HCC versus partially treated/untreated HCC.
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