Relationships between obesity markers and bone parameters in community-dwelling older adults.

BACKGROUND: Osteoporosis is an age-related condition that can lead to fragility fractures and other serious consequences. The literature data on the impact of obesity on bone health are contradictory. The main reasons for this discrepancy could be the imperfect nature of the body mass index (BMI) as a marker of obesity, the metabolic status (inflammation and metabolically healthy obesity), and/or heterogeneity in bone variables and architecture or sex. AIMS: To examine the relationship between bone variables and three validated obesity criteria. METHODS: In this cross-sectional study, participants were classified as obese according to their BMI, waist circumference (WC), and fat mass (FM). Bone variables and architecture were assessed using dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, respectively. RESULTS: One hundred sixty-eight adults aged 55 or over (men: 68%) were included. 48 (28%) participants were obese according to the BMI, with 108 (64%) according to the FM, and 146 (87%) according to the WC. Bone variables were positively correlated with WC and BMI (Pearson's r = 0.2-0.42). In men only, the obesity measures were negatively correlated with cortical bone density (Pearson's r = - 0.32 to - 0.19) and positively correlated with cortical bone area (Pearson's r = 0.22-0.39). CONCLUSION: Our findings indicate that independent of sex and obesity criteria, when significant, being obese seems to lead to higher bone parameters than being non-obese, except for cortical bone density. Thus, in the obese population, assessing cortical density might help the physician to identify bone alteration. Further researches are needed to confirm our findings.

["Connected device for monitoring patients treated by prostatectomy: Implementation and qualitative assessment"]. / Dispositif connecté de suivi des patients traités par prostatectomie totale : mise en place et évaluation qualitative.

INTRODUCTION: Support care aims to improve the experience of patients. m-health is one of the tools recently developed to promote patient empowerment. The objective of this study was to evaluate the appreciation of an m-health application to enhance prostatectomy path for patients suffering from prostate cancer. METHOD: A prospective monocentric study was conducted in the urology department of the University Hospital of Rennes from February to April 2023. MyCHU application was optimized by integrating information sheets in the postoperative period after prostatectomy on sphincter rehabilitation exercises, erectile dysfunction and urinary incontinence. The questionnaire used to evaluate the usability of "MyCHU" application was the System Usability Scale (SUS). Semi-structured interviews explored the patients' feelings about the content of the information sheets and the impact on their empowerment regarding sexual disorders. RESULTS: Twelve patients participated in this study and 7 agreed to complete an interview The average SUS score was 75.58, which indicate an high usability. Patients appreciated the fact that the application structured their healthcare pathway by centralizing information. The information sheets were clear and accurate. The impact on their empowerment was positive, with a gain in their ability to take ownership of the therapies. CONCLUSION: The role of digital technology in health care has been growing in recent years. Our study has shown the interest that mobile application can bring to the patient who undergoes prostatectomy. It increases his empowerment and favor the dialogue with his surgeon.

[Connected APA tools and prostate cancer: Literature review and experience feedback]. / Outils connectés d'APA et cancer de la prostate : revue de la littérature et retour d'expérience.

Adapted physical activity (APA) appears to be essential for supportive care in oncology. It helps to reduce different side effects inherent to treatment and disease (e.g., fatigue, sarcopenia, balance problems) and could have an impact on patients' survival. However, it is not systematically implemented in daily practice and still too few patients reach the recommendations of physical activity. New tools, such as digital and connected ones, are now developed to overcome barriers to the implementation and daily practice of physical activity (e.g., distance between home and hospital). The aim of this article was to provide an overview of different connected tools that offer exercise training and monitoring programmes in prostate cancer.

[Sexual and reproductive health of adolescents living with HIV in pediatric care programs in Abidjan : Structured provision of care and perceptions of health care workers in 2019]. / Santé sexuelle et reproductive des adolescent(e)s vivant avec le VIH dans les programmes de prise en charge pédiatrique à Abidjan : offre de services des structures et perceptions des professionnels de santé en 2019.

INTRODUCTION: The majority of adolescents living with HIV (ALHIV) reside in sub-Saharan Africa, with sexual and reproductive health (SRH) needs to be met. The health care facilities and professionals involved have a major role to assume in the quality of SRH services offered to these teenagers. OBJECTIVE: To investigate the SRH services offered to ALHIV subjects in pediatric facilities in Abidjan, Ivory-Coast. METHODS: In 2019 we conducted an exploratory cross-sectional study using qualitative and quantitative methods in three pediatric facilities caring for ALHIV subjects (CIRBA, CTAP and CePReF) and participating in the IeDEA (International epidemiologic databases to Evaluate AIDS project) in Abidjan, Ivory Coast. This study included: (1) an inventory of SRH services, using a questionnaire and direct observation, describing their adaptation to the teenagers' needs and their inclusion in provision of care; (2 an assessment by means of semi-structured interviews of 14 health professionals' perceptions of the SRH needs of the ALHIV subjects with whom they worked. Quantitative data were expressed in percentages and qualitative data from the interviews were analyzed through inductive thematic analysis. RESULTS: The care provided in the three facilities was poorly adapted to the teenagers' needs. Few SRH services were effectively provided to the ALHIV subjects in the different centers. The services essentially consisted in condom distribution and organization of SRH-based focus groups. Exceptionally, hormonal contraception was offered to teenage girls. Barriers to the services were largely due to poorly equipped facilities, particularly in terms of SRH offer, health professionals' experience, and support provided for ALHIV subjects and their parents. The health professionals were desirous of SRH skill-building programs enabling them to deliver optimal, adequately contextualized SRH services to the teenagers. CONCLUSIONS: In pediatric programs addressed to ALHIV subjects in three Abidjan facilities, the teenagers' SRH needs remain unmet. It is urgently necessary to strengthen the health facilities by means of improved equipment, enhanced awareness of teenagers' needs, and training programs enabling the health professionals to provide more adapted sexual and reproductive health services.

Prehabilitation in hepato-pancreato-biliary surgery: A systematic review and meta-analysis. A necessary step forward evidence-based sample size calculation for future trials.

INTRODUCTION: Prehabilitation is defined as preoperative conditioning of patients in order to improve post-operative outcomes. Some studies showed an increase in functional recovery following colorectal surgery, but its effect in hepato-pancreato-biliary (HPB) surgery is unclear. The aim of this study was to realize a systematic literature review and meta-analysis on the current available evidence on prehabilitation in HPB surgery. MATERIALS AND METHODS: A systematic review and a metanalysis were carried out on prehabilitation (physical, nutritional and psychological interventions) in HPB surgery (2009-2019). Assessed outcomes were postoperative complications, length of stay (LOS), 30-day readmission, and mortality. MAIN RESULTS: Four studies among the 191 screened were included in this systematic review (3 randomized controlled trials, 1 case-control propensity score study), involving 419 patients (prehabilitation group, n=139; control group, n=280). After pooling, no difference was observed on LOS ((-4.37 days [95% CI: -8.86; 0.13]) or postoperative complications (RR 0.83 [95%CI: 0.62; 1.10]), reported by all the included studies. Two trials reported on readmission rate, but given the high heterogeneity, a meta-analysis was not realized. No deaths were reported among the included studies. CONCLUSION: No effect of prehabilitation programs in HPB surgery was observed on LOS or postoperative complications rate. Future trials with standardized outcomes of measure, and adequately powered samples calculations are thus required. PROSPERO REGISTRATION: CRD42020165218.

How do we improve adolescent diet and physical activity in India and sub-Saharan Africa? Findings from the Transforming Adolescent Lives through Nutrition (TALENT) consortium.

OBJECTIVE: Adolescent diet, physical activity and nutritional status are generally known to be sub-optimal. This is an introduction to a special issue of papers devoted to exploring factors affecting diet and physical activity in adolescents, including food insecure and vulnerable groups. SETTING: Eight settings including urban, peri-urban and rural across sites from five different low- and middle-income countries. DESIGN: Focus groups with adolescents and caregivers carried out by trained researchers. RESULTS: Our results show that adolescents, even in poor settings, know about healthy diet and lifestyles. They want to have energy, feel happy, look good and live longer, but their desire for autonomy, a need to 'belong' in their peer group, plus vulnerability to marketing exploiting their aspirations, leads them to make unhealthy choices. They describe significant gender, culture and context-specific barriers. For example, urban adolescents had easy access to energy dense, unhealthy foods bought outside the home, whereas junk foods were only beginning to permeate rural sites. Among adolescents in Indian sites, pressure to excel in exams meant that academic studies were squeezing out physical activity time. CONCLUSIONS: Interventions to improve adolescents' diets and physical activity levels must therefore address structural and environmental issues and influences in their homes and schools, since it is clear that their food and activity choices are the product of an interacting complex of factors. In the next phase of work, the Transforming Adolescent Lives through Nutrition consortium will employ groups of adolescents, caregivers and local stakeholders in each site to develop interventions to improve adolescent nutritional status.

[Management of hormone deprivation therapies in prostate cancer: Role of the nurse]. / Hormonothérapie dans le cancer de la prostate : quel rôle pour l'IDE en 2020 ?

Hormone deprivation therapies play a key role in the treatment of prostate cancer. These treatments require standardized care and regular monitoring. The objective of this work was to review the different hormonal therapies available, their side effects and the role of a coordinating nurse in the management of these therapies. First generation hormone therapy is the standard treatment for metastatic prostate cancer. In the past years, second generation hormone therapies have been indicated in combination with first-generation hormone therapies at different stages of the disease. These molecules are responsible for several side effects that should be monitored and prevented. Thus, after an initial assessment, clinical and paraclinical follow-up are essential. Our center has set up monitoring by a coordinating nurse (IDEC) to optimize the education and follow-up of the patient, but also to provide psychosocial support adapted throughout the patient's care path under hormone therapy. This monitoring and information function by IDEC can be facilitated by new digital solutions.

[Patients with prostate cancer treated by androgen deprivation therapy: Impact of adapted physical activity]. / Patients avec un cancer de la prostate traités par hormonothérapie : impact de l'activité physique adaptée.

OBJECTIVES: The purpose of this article is to present adapted physical activity (APA) and its potential impact on the androgen deprivation therapy (ADT) adverse effects, the limits and measures to promote its use among prostate cancer (PCa) patients treated with ADT. MATERIAL AND METHODS: A non-systematic review of the literature was performed with pubmed referenced articles, using the keywords "prostate cancer", "androgen deprivation" and "physical activity", and the main publications and recommendations of national and international health agencies, published between January 2010 and June 2019. RESULTS: APA represents an effective action to reduce adverse effects of ADT. Its integration into health care of PCa patients treated with ADT remains limited. CONCLUSION: To promote a APA development in this population, a multidisciplinary collaboration between healthcare and APA professionals is essential. This collaboration should enable implementation of standard and innovative APA programs and therapeutic education tools for patients, as well as development of information and promotion for healthcare professionals.

Using longitudinal targeted maximum likelihood estimation in complex settings with dynamic interventions.

Longitudinal targeted maximum likelihood estimation (LTMLE) has very rarely been used to estimate dynamic treatment effects in the context of time-dependent confounding affected by prior treatment when faced with long follow-up times, multiple time-varying confounders, and complex associational relationships simultaneously. Reasons for this include the potential computational burden, technical challenges, restricted modeling options for long follow-up times, and limited practical guidance in the literature. However, LTMLE has desirable asymptotic properties, ie, it is doubly robust, and can yield valid inference when used in conjunction with machine learning. It also has the advantage of easy-to-calculate analytic standard errors in contrast to the g-formula, which requires bootstrapping. We use a topical and sophisticated question from HIV treatment research to show that LTMLE can be used successfully in complex realistic settings, and we compare results to competing estimators. Our example illustrates the following practical challenges common to many epidemiological studies: (1) long follow-up time (30 months); (2) gradually declining sample size; (3) limited support for some intervention rules of interest; (4) a high-dimensional set of potential adjustment variables, increasing both the need and the challenge of integrating appropriate machine learning methods; and (5) consideration of collider bias. Our analyses, as well as simulations, shed new light on the application of LTMLE in complex and realistic settings: We show that (1) LTMLE can yield stable and good estimates, even when confronted with small samples and limited modeling options; (2) machine learning utilized with a small set of simple learners (if more complex ones cannot be fitted) can outperform a single, complex model, which is tailored to incorporate prior clinical knowledge; and (3) performance can vary considerably depending on interventions and their support in the data, and therefore critical quality checks should accompany every LTMLE analysis. We provide guidance for the practical application of LTMLE.

Hepatitis C subtype distribution in chronically infected patients with mild liver fibrosis in France: the GEMHEP study.

Treatment options for Hepatitis C infection have greatly improved with direct-acting antiviral (DAA) combinations achieving high cure rates. Nevertheless, the cost of this treatment is still high and access to treatment in many countries has been preferentially reserved for patients with more severe fibrosis (F3 and F4). In this French nationwide study, we investigated the epidemiological characteristics and genotype distribution of hepatitis C virus (HCV) in treatment-naive patients with METAVIR fibrosis stages between F0 and F2 in order to identify patient profiles that became eligible for unrestricted treatment in a second period. Between 2015 and 2016 we collected data from nine French university hospitals on a total of 584 HCV positive patients with absent, mild or moderate liver fibrosis. The most represented genotypes were genotype 1b (159/584; 27.2%), followed by genotype 1a (150/584; 25.7%); genotype 3 (87/584: 14.9%); genotype 4 (80/584; 13.7%). Among genotype 4: 4a was predominantly encountered with 22 patients (27.5% of genotype 4). Genotypes 1b and 1a are currently the most frequent virus types present in treatment-naive patients with mild fibrosis in France. They can be readily cured using the available DAA. Nevertheless, non-a/non-d genotype 4 is also frequent in this population and clinical data on the efficacy of DAA on these subtypes is missing. The GEMHEP is the French group for study and evaluation of viral hepatitis on a national scale. Data collection on epidemiological and molecular aspects of viral hepatitis is performed on a regular basis in all main French teaching hospitals and serves as a basis for surveillance of these infections. Analysis and trends are regularly published on behalf of the GEMHEP group. Data collection was performed retrospectively over the 2015-2016 period, covering nine main university hospitals in France. A total of 584 hepatitis C positive patients were included in this study. Genotyping of the circulating viruses showed a high prevalence of genotypes 1b and 1a in our population. The epidemiology of hepatitis C is slowly changing in France, particularly as a consequence of the rise of 'non-a non-d' genotype 4 viruses mainly originating from African populations. More data concerning treatment efficacy of these genotypes is needed in order to guide clinical care.

[HIV Disclosure to the Child/Adolescent in Central and West Francophone Africa]. / Annonce à l'enfant et à l'adolescent de son statut VIH en Afrique francophone centrale et de l'Ouest.

We report the attitudes and practices of health care workers involved in the disclosure process to adolescents living with HIV (ALHIV) in a network including West and Central African French-speaking countries, and the experiences of young living with HIV (YLHIV). During a three-day workshop in Abidjan, Côte d'Ivoire, caregivers (doctors, psychologists, social workers) from 19 pediatric HIV treatment sites shared their practices and difficulties, and four YPLHIV their own disclosure experience. Thirty five participants from eight West/Central African countries (Benin, Burkina Faso, Ivory Coast, Cameroon, Mali, Democratic Republic of Congo, Senegal, Togo) contributed: 14 doctors, eight psychologists, six counselors, three social workers. The experience of the centers was variable, but the age at disclosure was late: 34% of 1296 adolescents between 10 and 12 years of age knew their status. The median age at disclosure was 13 years (range: 11-15 years). The practice of the disclosure was often complex, because of multiple factors (fear of the parents of the breaking of the secrecy, lack of communication between professionals). The individual disclosure was the main practice. Four centers practiced HIV disclosure in group sessions to facilitate mirror support, and one used peer-to-peer support. YPLHIV have advocated for an earlier disclosure, from 10 years. In West and Central Africa, the process of HIV disclosure remains complex for parents and caregivers, and occurs too late. The development of a good practice guideline for HIV disclosing adapted to socio-cultural contexts should help to improve this process.

Nous rapportons les attitudes et pratiques des soignants en Afrique francophone concernant l'annonce du statut VIH aux adolescents, et les témoignages de jeunes vivant avec le VIH (jvVIH). Lors d'un atelier de trois jours à Abidjan, Côte d'Ivoire, en novembre 2016, les soignants (médecins, psychologues, travailleurs sociaux) de 19 sites de prise en charge pédiatrique du VIH ont partagé leurs pratiques et difficultés et 4 jvVIH leur vécu de l'annonce. Au total, 35 participants de 8 pays d'Afrique de l'Ouest/centrale (Bénin, Burkina Faso, Côte d'Ivoire, Cameroun, Mali, République démocratique du Congo, Sénégal, Togo) ont contribué : 14 médecins, 8 psychologues, 6 conseillers, 3 travailleurs sociaux. L'expérience des centres était variable, mais l'âge à l'annonce restait tardif : 34 % des 1 296 adolescents âgés entre 10 et 12 ans connaissaient leur statut. L'âge médian à l'annonce était de 13 ans (étendue : 11-15 ans). La pratique de l'annonce s'avérait complexe, en raison de multiples facteurs (crainte des parents de la rupture du secret, manque de communication entre professionnels). L'annonce individuelle était la pratique majoritairement adoptée. Quatre centres pratiquaient une annonce en séances de groupe pour faciliter le soutien en miroir, et un avait recours à l'appui de pairs-adolescents. Les jvVIH ont plaidé pour une annonce plus précoce, dès 10 ans. En Afrique de l'Ouest/centrale francophone, le processus de l'annonce reste complexe pour parents et soignants, et l'annonce trop tardive. L'élaboration d'un guide de bonnes pratiques de l'annonce du VIH, adapté aux contextes socio-culturels devrait permettre d'améliorer ce processus.

Using high-throughput sequencing for investigating intra-host hepatitis C evolution over long retrospective periods.

Collections of biological samples held by hospitals represent invaluable resources for conducting retrospective evolutionary studies of chronic infections. Using high-throughput sequencing, those collections permit analysis of within-host genetic diversity over long follow-up periods, and allow a better understanding of resistance to treatment regimes during disease evolution. Here, we studied the evolution of hepatitis C virus (HCV) populations in two patients with an absence of response to dual therapies. We implemented amplicon sequencing to survey genomic variation at the Core and NS5B regions of HCV over a period of 13 years from blood samples obtained at multiple time points. We observed mixed infection by multiple HCV genotypes in both patients. Genetic heterogeneity and sample composition analysis provided information about the changes in viral population over the course of clinical treatment, with NS5B experiencing an increase in diversity after treatment initiation. Secondary infections were estimated to predate treatment year, and our results pointed towards diversifying selection occurring post-treatment, acting on standing genomic variation and maintaining high genetic heterogeneity during infection. For these two patients infected with multiple HCV genotypes, the maintenance of viral diversity was explained with the hypothesis of soft selective sweep started at the same time as antiviral treatment was initiated.

Safety of sofosbuvir-based regimens after liver transplantation: longitudinal assessment of renal function in the prospective ANRS CO23 CUPILT study.

BACKGROUND: In liver transplant recipients with hepatitis C virus recurrence, there is concern about renal safety of sofosbuvir-based regimens. Changes in serum creatinine or in the estimated glomerular filtration rate (eGFR) under treatment are used to look for possible renal toxicity. However, serum creatinine and eGFR are highly variable. AIM: To analyse renal function trajectory with numerous assays of serum creatinine over a long period of time. METHODS: In a multicentre cohort of 139 patients, the eGFR was obtained from serum creatinine using the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation. Slopes of eGFR were defined as a change in eGFR during a period divided by time. Pre-treatment, on-treatment and post-treatment periods were 9 months, 3-9 months and 4.5 months. Interactions between eGFR slopes and the pre-treatment eGFR, use of ribavirin or mycophenolate mofetil, and stage of fibrosis were addressed. On-treatment eGFR slopes were separated in tertiles. Pre- and post-treatment eGFR slopes were compared globally and according to tertiles. RESULTS: The post-treatment eGFR slope was significantly better than pre-treatment eGFR slope (+0.18 (IQR -0.76 to +1.32) vs -0.11 (IQR -1.01 to +0.73) mL/min/1.73 m2 /month, P = 0.03) independently of the pre-treatment eGFR (P = 0.99), ribavirin administration (P = 0.26), mycophenolate mofetil administration (P = 0.51) and stage of fibrosis (F3 and F4 vs lower stages, P = 0.18; F4 vs lower stages, P = 0.08; F4 Child-Pugh B and C vs lower stages, P = 0.38). Tertiles of on-treatment eGFR slopes were -1.71 (IQR -2.54 to -1.48), -0.78 (IQR -1.03 to -0.36) and +0.75 (IQR +0.28 to +1.47) mL/min/1.73 m2 /month. Pre- and post-treatment eGFR slopes were not significantly different according to tertiles (respectively, P = 0.34, 0.08, 0.73). CONCLUSION: The eGFR varies during treatment and gives a confusing picture of the renal safety of sofosbuvir-based regimens. In contrast, longitudinal assessment of the eGFR shows a rising trajectory over longer time, meaning that these therapies are safe for the kidneys in our cohort of liver transplant recipients.

Efficacy, safety and patient-reported outcomes of ledipasvir/sofosbuvir in NS3/4A protease inhibitor-experienced individuals with hepatitis C virus genotype 1 and HIV coinfection with and without cirrhosis (ANRS HC31 SOFTRIH study).

OBJECTIVES: Studies evaluating the efficacy and safety of the fixed-dose combination ledipasvir (LDV)/sofosbuvir (SOF) in patients coinfected with HIV-1 and hepatitis C virus (HCV) have mainly included treatment-naïve patients without cirrhosis. We aimed to evaluate the efficacy and safety of this combination in treatment-experienced patients with and without cirrhosis. METHODS: We conducted a multicentre, open-label, double-arm, nonrandomized study in patients coinfected with HIV-1 and HCV genotype 1 with and without cirrhosis, who had good viral suppression on their antiretroviral regimens. All patients were pretreated with a first-generation NS3/4A protease inhibitor (PI) plus pegylated interferon/ribavirin. Patients received a fixed-dose combination of LDV/SOF for 12 weeks, or for 24 weeks if cirrhosis was present. The primary endpoint was a sustained virological response (SVR) 12 weeks after the end of therapy. Secondary endpoints included safety, pharmacokinetics and patient-reported outcomes. RESULTS: Of the 68 patients enrolled, 39.7% had cirrhosis. Sixty-five patients [95.6%; 95% confidence interval (CI): 87.6-99.1%; P < 0.0001] achieved an SVR, with similar rates of SVR in those with and without cirrhosis. Tolerance was satisfactory, with mainly grade 1 or 2 adverse events. Among patient-reported outcomes, only fatigue significantly decreased at the end of treatment compared with baseline [odds ratio (OR): 0.36; 95% CI: 0.14-0.96; P = 0.04]. Mean tenofovir area under the plasma concentration-time curve (AUC) at week 4 was high, with mean ± SD AUC variation between baseline and week 4 higher in cirrhotic than in noncirrhotic patients (3261.57 ± 1920.47 ng/mL vs. 1576.15 ± 911.97 ng/mL, respectively; P = 0.03). Mild proteinuria (54.4%), hypophosphataemia (50.0%), blood bicarbonate decrease (29.4%) and hypokalaemia (13.2%) were reported. The serum creatinine level was not modified. CONCLUSIONS: LDV/SOF provided a high SVR rate in PI-experienced subjects coinfected with HCV genotype 1 and HIV-1, including patients with cirrhosis.

Challenges and perspectives of compliance with pediatric antiretroviral therapy in Sub-Saharan Africa.

More than 3 million children aged less than 15years are infected with HIV worldwide, mainly in Sub-Saharan Africa. The survival of HIV-infected children depends on their access to antiretroviral therapy whose success mainly depends on a good life-long compliance with antiretroviral therapy. Given its complexity and specificity, assessment and monitoring of pediatric compliance with antiretroviral therapy is a major challenge. There is no consensus on a gold standard for monitoring compliance with antiretroviral therapy. Compliance is also influenced by many factors related to the child, the caregiver, the healthcare staff, the healthcare system, and antiretroviral drugs. This review aimed to assess scientific knowledge on pediatric compliance with antiretroviral therapy in Sub-Saharan Africa, and to identify areas for future interventions to improve compliance. Good compliance is essential to achieve the "90% coverage of children on antiretroviral therapy" gold standard of the World Health Organization, and to eliminate HIV infection by 2030.

Ultrasonic subwavelength phase conjugated mirror with a layer of bubbles.

A single layer of gas bubbles in a yield-stress fluid is experimentally shown to behave as a phase-conjugated (PC) mirror with a thickness 250 times smaller than the wavelength (0.14mm-diameter bubbles for phase-conjugation at 40kHz). A high amplitude pump wave at frequency 80kHz interacts with a lower amplitude probe wave centered at 40kHz. A PC-reflection coefficient of 0.15 is obtained for a 50kPa pump. A perturbative second-order theory is shown to quantitatively describe the experimental observations.

Amplification and pyrosequencing of near-full-length hepatitis C virus for typing and monitoring antiviral resistant strains.

Directly acting antiviral drugs have contributed considerable progress to hepatitis C virus (HCV) treatment, but they show variable activity depending on virus genotypes and subtypes. Therefore, accurate genotyping including recombinant form detection is still of major importance, as is the detection of resistance-associated mutations in case of therapeutic failure. To meet these goals, an approach to amplify the HCV near-complete genome with a single long-range PCR and sequence it with Roche GS Junior was developed. After optimization, the overall amplification success rate was 73% for usual genotypes (i.e. HCV 1a, 1b, 3a and 4a, 16/22) and 45% for recombinant forms RF_2k/1b (5/11). After pyrosequencing and subsequent de novo assembly, a near-full-length genomic consensus sequence was obtained for 19 of 21 samples. The genotype and subtype were confirmed by phylogenetic analysis for every sample, including the suspected recombinant forms. Resistance-associated mutations were detected in seven of 13 samples at baseline, in the NS3 (n = 3) or NS5A (n = 4) region. Of these samples, the treatment of one patient included daclatasvir, and that patient experienced a relapse. Virus sequences from pre- and posttreatment samples of four patients who experienced relapse after sofosbuvir-based therapy were compared: the selected variants seem too far from the NS5B catalytic site to be held responsible. Although tested on a limited set of samples and with technical improvements still necessary, this assay has proven to be successful for both genotyping and resistance-associated variant detection on several HCV types.