First human surgery using a surgical assistance robotics device for laparoscopic cholecystectomies

BACKGROUND

Over the past 20 years, surgeons involved in soft tissue minimally invasive surgery have experienced the pros and cons of both conventional and tele-robotic laparoscopic approaches. The Maestro System, developed by Moon Surgical (Paris, France) aims to overcome the challenges inherent to both approaches thanks to a new concept that augments the surgeon's performance at the bedside during a laparoscopic procedure.

METHODS

The current study aims to present the first human experience with laparoscopic cholecystectomy with the Maestro system on 10 patients.

RESULTS

All ten procedures were completed successfully. No significant complications related to the use of the Maestro system werenoted.

CONCLUSION

Our preliminary observations appear to support the benefits of the Maestro system in non-emergent laparoscopic cholecystectomies. It goes without saying that further research is necessary to demonstrate the safety of this approach in other procedures.

Establishment of a 96-well transwell system using primary human gut organoids to capture multiple quantitative pathway readouts

Disruptions in the gut epithelial barrier can lead to the development of chronic indications such as inflammatory bowel disease (IBD). Historically, barrier function has been assessed in cancer cell lines, which do not contain all human intestinal cell types, leading to poor translatability. To bridge this gap, we adapted human primary gut organoids grown as monolayers to quantify transcription factor phosphorylation, gene expression, cytokine production, and barrier function. In this work we describe and characterize a novel 96-well human gut organoid-derived monolayer system that enables quantitative assessment of candidate therapeutics. Normal human intestine differentiation patterns and barrier function were characterized and confirmed to recapitulate key aspects of in vivo biology. Next, cellular response to TNF-α (a central driver of IBD) was determined using a diverse cadre of quantitative readouts. We showed that TNF-α pathway antagonists rescued damage caused by TNF-α in a dose-dependent manner, indicating that this system is suitable for quantitative assessment of barrier modulating factors. Taken together, we have established a robust primary cell-based 96-well system capable of interrogating questions around mucosal response. This system is well suited to provide pivotal functional data to support translational target and drug discovery efforts.

Crocodile perception of distress in hominid baby cries

It is generally argued that distress vocalizations, a common modality for alerting conspecifics across a wide range of terrestrial vertebrates, share acoustic features that allow heterospecific communication. Yet studies suggest that the acoustic traits used to decode distress may vary between species, leading to decoding errors. Here we found through playback experiments that Nile crocodiles are attracted to infant hominid cries (bonobo, chimpanzee and human), and that the intensity of crocodile response depends critically on a set of specific acoustic features (mainly deterministic chaos, harmonicity and spectral prominences). Our results suggest that crocodiles are sensitive to the degree of distress encoded in the vocalizations of phylogenetically very distant vertebrates. A comparison of these results with those obtained with human subjects confronted with the same stimuli further indicates that crocodiles and humans use different acoustic criteria to assess the distress encoded in infant cries. Interestingly, the acoustic features driving crocodile reaction are likely to be more reliable markers of distress than those used by humans. These results highlight that the acoustic features encoding information in vertebrate sound signals are not necessarily identical across species.

Is a giant incisional hernia a contraindication for laparoscopic cholecystectomy?

Laparoscopic cholecystectomy (LC) is one of the most commonly performed surgical procedures worldwide. A previous abdominal operation is not considered a significant risk factor for conversion to open cholecystectomy. We describe the case of an 80-year-old woman with a surgical history of a giant uncomplicated incisional midline hernia presenting at our department with choledocholithiasis and acute cholangitis. After an ERCP with extraction of common bile duct stones, a LC was planned. The first trocar was inserted in the right midclavicular line, using an open technique and a careful inspection of the abdominal cavity and the hernia sac content. An uncomplicated cholecystectomy was performed and the postoperative course was uneventful.

Anthropogenic noise does not strengthen multiple-predator effects in a freshwater invasive fish

Anthropogenic noise has the potential to alter community dynamics by modifying the strength of nested ecological interactions such as predation. Direct effects of noise on per capita predation rates have received much attention but the context in which predation occurs is often oversimplified. For instance, many animals interact with conspecifics while foraging and these nontrophic interactions can positively or negatively influence per capita predation rates. These effects are often referred to as multiple-predator effects (MPEs). The extent to which noise can modulate MPEs and thereby indirectly alter per capita predation remains unknown. To address this question, we derived the relationship between per capita predation rate and prey density, namely the functional response (FR), of single and pairs of the invasive topmouth gudgeon Pseudorasbora parva when feeding on water fleas under two noise conditions: control ambient noise estimated at 95 dB re 1 μPa and ambient noise supplemented with motorboat sounds whose relative importance over ambient noise ranged from 4.81 to 27 dB. In addition, we used video recordings to track fish movements. To detect MPEs, we compared the observed group-level FRs to predicted group-level FRs inferred from the individual FRs and based on additive effects only. Regardless of the number of fish and the noise condition, the FR was always of type II, showing predation rate in a decelerating rise to an upper asymptote. Compared to the noiseless condition, the predation rate of single fish exposed to noise did not differ at high prey densities but was significantly lower at low prey densities, resulting in an FR with the same asymptote but a less steep initial slope. Noise also reduced fish mobility, which might explain the decrease in predation rate at low prey densities. Conspecific presence suppressed the individual response to noise, the FRs of two fish (observed group-level FRs) being perfectly similar between the two noise conditions. Although observed and predicted group-level FRs did not differ significantly, observed group-level FRs tended to fall in the low range of predicted group-level FRs, suggesting antagonism and a negative effect of nontrophic interactions on individual foraging performance. Interestingly, the difference between predicted and observed group-level FRs was not greater with noise, which means that noise did not strengthen MPEs. Our results show that when considering the social context of foraging, here through the presence of a conspecific, anthropogenic noise does not compromise foraging in the invasive P. parva.

Sound categorization by crocodilians

Rapidly sorting the information contained in a stream of stimuli is a major challenge for animals. One cognitive mechanism for achieving this goal is categorization, where the receiving individual considers a continuous variation of a stimulus as belonging to discrete categories. Using playback experiments in a naturalistic setup, here we show that crocodiles confronted with an acoustic continuum ranging from a frog call to a crocodile call classify each acoustic variant into one of these two categories, establishing a meaningful boundary where no acoustic boundary exists. With GO/NO-GO experiments, we then observe that this boundary is defined along the continuum following learning. We further demonstrate that crocodilians rely on the spectral envelope of sounds to categorize stimuli. This study suggests that sound categorization in crocodilians is a pre-wired faculty allowing rapid decision-making and highlights the learning-dependent plasticity involved in defining the boundary between sound categories.

Renal medicine in the intensive care unit: a narrative review

Kidney disease, both acute and chronic, is commonly encountered on the intensive care unit. Due to the role the kidneys play in whole body homeostasis, it follows that their dysfunction has wide-ranging implications and can affect prescribing and therapeutic management. This narrative review discusses the pathophysiology of acute kidney injury and chronic kidney disease, and how this relates to critically unwell patients. We cover several aspects of the management of renal dysfunction on the critical care unit, exploring some of the recurrent themes within the literature, including type and timing of kidney replacement therapy, management of acute kidney injury, as well as discussing how novel biomarkers for acute kidney injury may help to identify patients suffering from acute kidney injury as well as risk stratifying these patients. We discuss how early involvement of specialist nephrology services can improve outcomes in patients with kidney disease as well as offer valuable diagnostic and specialist management advice, particularly for patients with established end stage kidney disease and patients who are already known to nephrology services. We also explore some of the ongoing research questions that need to be answered within this arena.

Spatial release from masking in crocodilians

Ambient noise is a major constraint on acoustic communication in both animals and humans. One mechanism to overcome this problem is Spatial Release from Masking (SRM), the ability to distinguish a target sound signal from masking noise when both sources are spatially separated. SRM is well described in humans but has been poorly explored in animals. Although laboratory tests with trained individuals have suggested that SRM may be a widespread ability in vertebrates, it may play a limited role in natural environments. Here we combine field experiments with investigations in captivity to test whether crocodilians experience SRM. We show that 2 species of crocodilians are able to use SRM in their natural habitat and that it quickly becomes effective for small angles between the target signal source and the noise source, becoming maximal when the angle exceeds 15^∘. Crocodiles can therefore take advantage of SRM to improve sound scene analysis and the detection of biologically relevant signals.

The ability to separate target sound signals from masking noise is identified in wild and captive crocodilian species.

Accelerated Identification of Cell Active KRAS Inhibitory Macrocyclic Peptides using Mixture Libraries and Automated Ligand Identification System (ALIS) Technology

Macrocyclic peptides can disrupt previously intractable protein–protein interactions (PPIs) relevant to oncology targets such as KRAS. Early hits often lack cellular activity and require meticulous improvement of affinity, permeability, and metabolic stability to become viable leads. We have validated the use of the Automated Ligand Identification System (ALIS) to screen oncogenic KRAS^G12D (GDP) against mass-encoded mini-libraries of macrocyclic peptides and accelerate our structure–activity relationship (SAR) exploration. These mixture libraries were generated by premixing various unnatural amino acids without the need for the laborious purification of individual peptides. The affinity ranking of the peptide sequences provided SAR-rich data sets that led to the selection of novel potency-enhancing substitutions in our subsequent designs. Additional stability and permeability optimization resulted in the identification of peptide 7 that inhibited pERK activity in a pancreatic cancer cell line. More broadly, this methodology offers an efficient alternative to accelerate the fastidious hit-to-lead optimization of PPI peptide inhibitors.

Discovery of cell active macrocyclic peptides with on-target inhibition of KRAS signaling

Macrocyclic peptides have the potential to address intracellular protein–protein interactions (PPIs) of high value therapeutic targets that have proven largely intractable to small molecules. Here, we report broadly applicable lessons for applying this modality to intracellular targets and specifically for advancing chemical matter to address KRAS, a protein that represents the most common oncogene in human lung, colorectal and pancreatic cancers yet is one of the most challenging targets in human disease. Specifically, we focused on KRpep-2d, an arginine-rich KRAS-binding peptide with a disulfide-mediated macrocyclic linkage and a protease-sensitive backbone. These latter redox and proteolytic labilities obviated cellular activity. Extensive structure–activity relationship studies involving macrocyclic linker replacement, stereochemical inversion, and backbone α-methylation, gave a peptide with on-target cellular activity. However, we uncovered an important generic insight – the arginine-dependent cell entry mechanism limited its therapeutic potential. In particular, we observed a strong correlation between net positive charge and histamine release in an ex vivo assay, thus making this series unsuitable for advancement due to the potentially fatal consequences of mast cell degranulation. This observation should signal to researchers that cationic-mediated cell entry – an approach that has yet to succeed in the clinic despite a long history of attempts – carries significant therapy-limiting safety liabilities. Nonetheless, the cell-active molecules identified here validate a unique inhibitory epitope on KRAS and thus provide valuable molecular templates for the development of therapeutics that are desperately needed to address KRAS-driven cancers – some of the most treatment-resistant human malignancies.

Targeting undruggable intracellular proteins with peptides: novel on-target macrocyclic peptide inhibitors of KRAS with broad inhibition of proliferation of multiple KRAS-dependent cancer cell lines.

NanoClick: A High Throughput, Target-Agnostic Peptide Cell Permeability Assay

Macrocyclic peptides open new opportunities to target intracellular protein-protein interactions (PPIs) that are often considered nondruggable by traditional small molecules. However, engineering sufficient membrane permeability into these molecules is a central challenge for identifying clinical candidates. Currently, there is a lack of high-throughput assays to assess peptide permeability, which limits our capacity to engineer this property into macrocyclic peptides for advancement through drug discovery pipelines. Accordingly, we developed a high throughput and target-agnostic cell permeability assay that measures the relative cumulative cytosolic exposure of a peptide in a concentration-dependent manner. The assay was named NanoClick as it combines in-cell Click chemistry with an intracellular NanoBRET signal. We validated the approach using known cell penetrating peptides and further demonstrated a correlation to cellular activity using a p53/MDM2 model system. With minimal change to the peptide sequence, NanoClick enables the ability to measure uptake of molecules that enter the cell via different mechanisms such as endocytosis, membrane translocation, or passive permeability. Overall, the NanoClick assay can serve as a screening tool to uncover predictive design rules to guide structure-activity-permeability relationships in the optimization of functionally active molecules.

Crocodiles use both interaural level differences and interaural time differences to locate a sound source

To explore how crocodilians locate a sound source, two Nile crocodiles (Crocodylus niloticus) were trained to swim towards an acoustic target. Using filtered versions of synthesized stimuli, the respective roles of interaural level differences (ILDs) and interaural time differences (ITDs), which are the two main cues providing information on sound source position, were tested. This study shows that crocodiles rely on both ILDs and ITDs to locate the spatial direction of a sound source and that their performance is lower when one of the cues is lacking.

Influence of head morphology and natural postures on sound localization cues in crocodilians

As top predators, crocodilians have an acute sense of hearing that is useful for their social life and for probing their environment in hunting situations. Although previous studies suggest that crocodilians are able to localize the position of a sound source, how they do this remains largely unknown. In this study, we measured the potential monaural sound localization cues (head-related transfer functions; HRTFs) on alive animals and skulls in two situations, both mimicking natural positions: basking on the land and cruising at the interface between air and water. Binaural cues were also estimated by measuring the interaural level differences (ILDs) and the interaural time differences (ITDs). In both conditions, HRTF measurements show large spectral variations (greater than 10 dB) for high frequencies, depending on the azimuthal angle. These localization cues are influenced by head size and by the internal coupling of the ears. ITDs give reliable information regarding sound-source position for low frequencies, while ILDs are more suitable for frequencies higher than 1.5 kHz. Our results support the hypothesis that crocodilian head morphology is adapted to acquire reliable localization cues from sound sources when outside the water, but also when only a small part of their head is above the air-water interface.

Functional Analysis of Four Terpene Synthases in Rose-Scented Pelargonium Cultivars (Pelargonium × hybridum) and Evolution of Scent in the Pelargonium Genus

Pelargonium genus contains about 280 species among which at least 30 species are odorant. Aromas produced by scented species are remarkably diverse such as rose, mint, lemon, nutmeg, ginger and many others scents. Amongst odorant species, rose-scented pelargoniums, also named pelargonium rosat, are the most famous hybrids for their production of essential oil (EO), widely used by perfume and cosmetic industries. Although EO composition has been extensively studied, the underlying biosynthetic pathways and their regulation, most notably of terpenes, are largely unknown. To gain a better understanding of the terpene metabolic pathways in pelargonium rosat, we generated a transcriptome dataset of pelargonium leaf and used a candidate gene approach to functionally characterise four terpene synthases (TPSs), including a geraniol synthase, a key enzyme responsible for the biosynthesis of the main rose-scented terpenes. We also report for the first time the characterisation of a novel sesquiterpene synthase catalysing the biosynthesis of 10-epi-γ-eudesmol. We found a strong correlation between expression of the four genes encoding the respective TPSs and accumulation of the corresponding products in several pelargonium cultivars and species. Finally, using publically available RNA-Seq data and de novo transcriptome assemblies, we inferred a maximum likelihood phylogeny from 270 pelargonium TPSs, including the four newly discovered enzymes, providing clues about TPS evolution in the Pelargonium genus. Notably, we show that, by contrast to other TPSs, geraniol synthases from the TPS-g subfamily conserved their molecular function throughout evolution.

Appraisal of unimodal cues during agonistic interactions in Maylandia zebra

Communication is essential during social interactions including animal conflicts and it is often a complex process involving multiple sensory channels or modalities. To better understand how different modalities interact during communication, it is fundamental to study the behavioural responses to both the composite multimodal signal and each unimodal component with adequate experimental protocols. Here we test how an African cichlid, which communicates with multiple senses, responds to different sensory stimuli in a social relevant scenario. We tested Maylandia zebra males with isolated chemical (urine or holding water coming both from dominant males), visual (real opponent or video playback) and acoustic (agonistic sounds) cues during agonistic interactions. We showed that (1) these fish relied mostly on the visual modality, showing increased aggressiveness in response to the sight of a real contestant but no responses to urine or agonistic sounds presented separately, (2) video playback in our study did not appear appropriate to test the visual modality and needs more technical prospecting, (3) holding water provoked territorial behaviours and seems to be promising for the investigation into the role of the chemical channel in this species. Our findings suggest that unimodal signals are non-redundant but how different sensory modalities interplay during communication remains largely unknown in fish.

Cross-sensory modulation in a future top predator, the young Nile crocodile

Animals routinely receive information through different sensory channels, and inputs from a modality may modulate the perception and behavioural reaction to others. In spite of their potential adaptive value, the behavioural correlates of this cross-sensory modulation have been poorly investigated. Due to their predator life, crocodilians deal with decisional conflicts emerging from concurrent stimuli. By testing young Crocodylus niloticus with sounds in the absence or presence of chemical stimuli, we show that (i) the prandial (feeding) state modulates the responsiveness of the animal to a congruent, i.e. food-related olfactory stimulus, (ii) the prandial state alters the responsiveness to an incongruent (independent of food) sound, (iii) fasted, but not sated, crocodiles display selective attention to socially relevant sounds over noise in presence of food odour. Cross-sensory modulation thus appears functional in young Nile crocodiles. It may contribute to decision making in the wild, when juveniles use it to interact acoustically when foraging.

Baseline HBsAg and HBcrAg titres allow peginterferon-based 'precision medicine' in HBeAg-negative chronic hepatitis B patients

Quantitative hepatitis B core-related antigen (qHBcrAg) has been proposed as an additional marker to quantitative HBsAg (qHBsAg), for management of chronic hepatitis B. Evaluate baseline combination of qHBsAg and qHBcrAg for identification of patients that could benefit from pegylated interferon-alpha-2a (PegIFN)-based therapy. Sixty-two HBeAg-negative patients treated with PegIFN or PegIFN plus tenofovir disoproxil fumarate (PegIFN+TDF). HBsAg and HBcrAg titres were evaluated at baseline. Thirty patients received PegIFN and 32 PegIFN+TDF. SR was 10 of 30 and 17 of 32 in PegIFN and PegIFN+TDF patients, respectively. Cut-offs determined by maximized Youden's index for identifying patients likely to respond to therapy were as follows: 3.141 log₁₀ IU/mL and 3.450 log₁₀ U/mL for HBsAg and HBcrAg, respectively. At the end of 3 years post-treatment follow-up, HBsAg loss was observed in 7 of 30 and 6 of 32 in PegIFN and PegIFN+TDF patients, respectively. The AUC was estimated to be 0.716 (95% CI [0.578, 0.855]) for HBsAg and 0.668 (95% CI [0.524, 0.811]) for HBcrAg (P=.5541). PPVs for AUCs(95%CI) were 0.762(0.590-0.947), 0.714(0.533-1.000) and 0.800(0.611-1.000), and NPVs for AUCs(95%CI) were 0.756(0.660-0.899), 0.718(0.630-0.857) and 0.765(0.675-0.889) for qHBsAg, qHBcrAg and the combination of both markers, respectively. Baseline qHBsAg 3.141 log₁₀ IU/mL and qHBcrAg 3.450 log₁₀ U/mL thresholds used separately or in combination allow prediction of response, prior to PegIFN-based therapy, with a PPV of 80.3% and NPV of 76.5%. Baseline qHBsAg is predictive of HBsAg loss. Both markers could be used, separately or in combination, for PegIFN-based 'precision therapy'. Our results emphasize that the combination of PegIFN alpha-2a plus TDF with 53% of SR might be an alternative to finite therapy.

A Model-Based Illustrative Exploratory Approach to Optimize the Dosing of Peg-IFN/RBV in Cirrhotic Hepatitis C Patients Treated With Triple Therapy

Hézode et al. recently reported the frequent occurrence of anemia and thrombocytopenia in the ANRS-CO20-CUPIC cohort of hepatitis C virus (HCV) cirrhotic experienced patients treated with pegylated-interferon (Peg-IFN), ribavirin (RBV), and telaprevir or boceprevir.1,2 Using frequent measurements of serum drug concentrations, hemoglobin, and platelet concentrations obtained in 15 patients of this cohort, we show how an on-treatment model-based approach could be used to individualize dose regimen and avoid the occurrence of RBV-induced anemia and Peg-IFN-induced thrombocytopenia.

IFNL3 (IL28B) polymorphism does not predict long-term response to interferon therapy in HBeAg-positive chronic hepatitis B patients

The impact of IFNL3 (IL28B) polymorphism on response to interferon (IFN) treatment in patients infected with hepatitis B virus (HBV) is controversial. We aimed to investigate whether IFNL3 polymorphism (rs12979860) influences the long-term response of chronic hepatitis B (CHB) treatment to conventional IFN.

DESIGN

Ninety-seven HBeAg-positive patients treated with IFN were evaluated in this study. Associations were investigated between IFNL3 genotypes and (i) HBeAg seroconversion at the end of treatment (EOT), (ii) sustained virological response (SVR) and (iii) HBsAg seroconversion through long-term follow-up (LTFU). Patients were followed for a median of 14 years. The majority of patients were infected with HBV genotype A (69.6%) and were Caucasian (77.9%). Ninety-five patients were genotyped at rs12979860. Similar IFNL3 distribution was observed among the different ethnicities (P = 0.62) or across HBV genotypes A through G (P = 0.70). Thirty-six patients experienced HBeAg seroconversion at EOT; HBeAg seroconversion rates were 37.0 and 35.5% in patients with CC and CT/TT genotypes, respectively (P = 0.82). Among the 44 patients (45%) who achieved a SVR, SVR rates were 48.9 and 39.6% in patients with CC and CT/TT IL28B genotypes, respectively (P = 0.80). HBsAg seroconversion occurred through LTFU in 28 patients. HBsAg seroconversion rates were 25.5 and 31.2% in patients with CC and CT/TT genotypes, respectively (P = 0.51). No significant relationship between IFNL3 rs12979860 and fibrosis stage was observed (P = 0.85). IFNL3 genotype was neither associated with SVR, nor with HBeAg seroconversion and long-term HBsAg seroconversion in HBeAg-positive CHB patients responding to IFN therapy.

Design, Synthesis, and Optimization of Balanced Dual NK1/NK3 Receptor Antagonists

In connection with a program directed at potent and balanced dual NK1/NK3 receptor ligands, a focused exploration of an original class of peptidomimetic derivatives was performed. The rational design and molecular hybridization of a novel phenylalanine core series was achieved to maximize the in vitro affinity and antagonism at both human NK1 and NK3 receptors. This study led to the identification of a new potent dual NK1/NK3 antagonist with pK i values of 8.6 and 8.1, respectively.

The nucleus raphe magnus OFF-cells are involved in diffuse noxious inhibitory controls

Diffuse noxious inhibitory controls (DNIC) are very powerful long-lasting descending inhibitory controls which are pivotal in modulating the activity of spinal and trigeminal nociceptive neurons. DNIC are subserved by a loop involving supraspinal structures such as the lateral parabrachial nucleus and the subnucleus reticularis dorsalis. Surprisingly, though, whether the nucleus raphe magnus (NRM), another supraspinal area which is long known to be important in pain modulation, is involved in DNIC is still a matter of discussion. Here, we reassessed the role of the NRM neurons in DNIC by electrophysiologically recording from wide dynamic range (WDR) neurons in the trigeminal subnucleus oralis and pharmacologically manipulating the NRM OFF- and ON-cells. In control conditions, C-fiber-evoked responses in trigeminal WDR neurons are inhibited by a conditioning noxious heat stimulation applied to the hindpaw. We show that inactivating the NRM by microinjecting the GABAA receptor agonist, muscimol, both facilitates C-fiber-evoked responses of trigeminal WDR neurons and strongly attenuates their inhibition by heat applied to the hindpaw. Interestingly, selective blockade of ON-cells by microinjecting the broad-spectrum excitatory amino acid antagonist, kynurenate, into the NRM neither affects C-fiber-evoked responses nor attenuates DNIC of trigeminal WDR neurons. These results indicate that the NRM tonically inhibits trigeminal nociceptive inputs and is involved in the neuronal network underlying DNIC. Moreover, within NRM, OFF-cells might be more specifically involved in both the tonic and phasic descending inhibitory controls of trigeminal nociception.

Design and synthesis of potential dual NK(1)/NK(3) receptor antagonists

The tachykinin NK1 and NK3 receptors are a novel drug target for schizophrenia in order to treat not only the positive and cognitive symptoms, but also the associated co-morbid depression and sleep disturbances associated with the disease. A novel class of peptidomimetic derivatives based on a versatile phenylglycine central core was synthesized and tested in vitro as dual NK1/NK3 receptor antagonists. From this series emerged compounds with good NK1 receptor affinity, although only modest dual NK1/NK3 receptor affinity was observed with one of these analogs.

Abstract C212: Discovery of high affinity cyclic peptidomimetics binding Mcl-1 and Ras

Many well-validated oncology targets regulate signaling pathways through interactions with other proteins. Addressing these targets, which often lack suitable small molecule binding sites, requires larger and more complex molecules that are capable of binding relatively large or flat surfaces. We are testing whether this target class can be addressed by using in vitro selection to screen extremely large cyclic peptidomimetic libraries with novel design features.

Peptide-mRNA display libraries comprised of approximately 1 trillion cyclic peptidomimetics were created by in vitro translation using a mixture of natural, unnatural, and N-methylated amino acids. Pooled libraries were subjected to multiple rounds of selection and amplification to identify sequences that bound with high affinity to immobilized Mcl-1 or Ras.

Selected Mcl-1 cyclic peptidomimetics were synthesized and their binding and specificity were studied by surface plasmon resonance (SPR) using immobilized Mcl-1 and Bcl-2. Fluorescence polarization (FP) was used to demonstrate that isolated peptidomimetics competed with Bim-derived peptides (IC50≈100-400 nM), a measure of their ability to block the interactions between Mcl-1 and binding partners. The co-crystal structure of one Mcl-1 inhibitor revealed that the cyclic peptidomimetic bound the BH3 helix-binding grove by forming a β-hairpin, an unprecedented type of interaction with Bcl-2 family members. The cell permeability of analogs of this compound was verified by fluorescence microscopy and by induction of apoptosis.

In a second example, a cyclic peptidomimetic selected against mutant H-Ras was shown to bind both H-Ras and K-Ras with high affinity by SPR (KD=2.5 nM) and FP (Ki≈£10 nM). Despite its high affinity, this compound did not significantly impact Ras activity in several in vitro assays (GST-Raf-RBD binding, GTPase, and GDP/GTP exchange). A co-crystal structure with mutant K-Ras, however, revealed that this compound binds a novel site in the C-terminus of the Ras G-domain. Remarkably, this compound also forms a β-hairpin, and like the Mcl-1 compound, also appears to enter cells. Experiments to test how this compound may affect Ras signaling or localization, and the function of this novel site in cells or in vitro with full-length lipid modified Ras are in progress.

The target-bound conformation of both inhibitors reveled a network of intramolecular hydrogen bonds that are predicted to reduce interactions with water and may help to explain the intrinsic cell permeability of these molecules. The use of extremely large peptidomimetic libraries built with novel chemical diversity appears to be an extremely efficient platform for isolating high affinity binders for hard-to-target intracellular targets, yielding novel binding modes and binding sites that are unlikely to be identified by typical small molecule approaches or rational design.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C212.

Citation Format: Kristopher Josephson, Zhong Ma, Zhaolin Wang, Yili Sun, Sylvia Tobe, Sarah Perlmutter, Rohit Vyasamneni, Ping Ye, Nicolas Boyer, Micelle Arata, Kelli Pattavina, Kathleen Seyb, Hong Zheng, Imelda Sollomoni, Ezekiel Nims, Emily de Koning, Alonso Ricardo, Douglas Treco. Discovery of high affinity cyclic peptidomimetics binding Mcl-1 and Ras. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C212.

Synthesis and Anticancer Activity of Epipolythiodiketopiperazine Alkaloids

The epipolythiodiketopiperazine (ETP) alkaloids are a highly complex class of natural products with potent anticancer activity. Herein, we report the application of a flexible and scalable synthesis, allowing the construction of dozens of ETP derivatives. The evaluation of these compounds against cancer cell lines in culture allows for the first expansive structure-activity relationship (SAR) to be defined for monomeric and dimeric ETP-containing natural products and their synthetic cognates. Many ETP derivatives demonstrate potent anticancer activity across a broad range of cancer cell lines, and kill cancer cellsviainduction of apoptosis. Several traits thatbode well for the translational potential of the ETP class of natural products includeconcise and efficient synthetic access, potent induction of apoptotic cell death, activity against a wide range of cancer types, and a broad tolerance for modifications at multiple sitesthat should facilitate small-molecule drug development, mechanistic studies, and evaluation in vivo.

Concise Total Synthesis of (+)-Gliocladins B and C

The first total synthesis of (+)-gliocladin B is described. Our concise and enantioselective synthesis takes advantage of a new regioselective Friedel-Crafts-based strategy to provide an efficient multigram-scale access to the C3-(3'-indolyl)hexahydropyrroloindole substructure, a molecular foundation present in a significant subset of epipolythiodiketopiperazine natural alkaloids. Our first-generation solution to (+)-gliocladin B involved the stereoselective formation of (+)-12-deoxybionectin A, a plausible biosynthetic precursor. Our synthesis clarified the C15 stereochemistry of (+)-gliocladin B and allowed its full structure confirmation. Further studies of a versatile dihydroxylated diketopiperazine provided a concise and efficient synthesis of (+)-gliocladin B as well as access to (+)-gliocladin C.

Sequential therapy with adefovir dipivoxil and pegylated interferon alfa-2a for HBeAg-negative patients

To assess the impact of sequential therapy with adefovir dipivoxil (ADV) and pegylated interferon alfa-2a (PEG-IFN) on virological (serum HBV-DNA) and serological (serum HBsAg) response in 20 consecutive HBeAg-negative patients. Patients received ADV for 20 weeks, then ADV and PEG-IFN for 4 weeks and lastly PEG-IFN for 44 weeks. Serum HBV-DNA and HBsAg were assessed at baseline, during therapy (weeks 20, 44 and 68) and follow-up (weeks 92 and 116). Sustained virological response (SVR) was defined as serum HBV-DNA <10 000 copies/mL (partial) or <70 copies/mL (complete) 24 weeks after stopping treatment. A serological response was defined as a serum HBsAg decrease ≥1 log(10) IU/mL at the end of treatment. Baseline median serum HBV-DNA and HBsAg levels were 7.6 log(10) copies/mL and 3.8 log(10) IU/mL, respectively. Ten patients (50%) achieved SVR, six of them had partial response and four complete response. Four patients (20%) achieved serological response. Complete SVRs showed a major and steep decline in HBsAg level with a median decrease of 0.5, 1.6 and 2.0 log(10) IU/mL at treatment week 20, 44 and 68, respectively. Partial SVRs showed a slight and slow decline in serum HBsAg level (0.1, 0.4, and 0.6 log IU/mL at weeks 20, 44 and 68, respectively). On-treatment serum HBsAg decrease had a high accuracy to predict SVR (AUROC = 0.88). Our results suggest that sequential therapy might be an interesting strategy for HBeAg-negative patients. Serum HBsAg kinetics seem to be an accurate tool to predict SVR. Large clinical trials are needed to explore this strategy with more potent analogues.

Total synthesis of oidiodendrolides and related norditerpene dilactones from a common precursor: metabolites CJ-14,445, LL-Z1271gamma, oidiolactones A, B, C, and D, and nagilactone F

An efficient, high-yielding strategy has been developed for the asymmetric total synthesis of seven norditerpenoid dilactones known for their diverse biological properties. The three key steps employed to obtain a tricyclic lactone intermediate involved a Morita-Baylis-Hillman reaction, the stereocontrolled construction of a gamma-lactone through bromolactonization, and an efficient catalytic Reformatsky-type reaction. Access to CJ-14,445, LL-Z1271gamma, oidiolactones A, B, C, and D, and nagilactone F was possible from a common intermediate. Structures and stereochemistry were determined by X-ray analysis.

Insulin resistance and geographical origin: major predictors of liver fibrosis and response to peginterferon and ribavirin in HCV-4

BACKGROUND AND AIMS

Hepatitis C virus (HCV) genotype 4 (HCV-4) is increasing in prevalence in Western countries. However, little is known about the severity of the disease and response to treatment. The aim of this study was to assess the predictors (logistic regression) of severe fibrosis (METAVIR score F3-F4), and sustained virological response (SVR) to peginterferon and ribavirin in 226 consecutive HCV-4 patients (Egyptians 40%, Europeans 35% and Africans 24%).

PATIENTS AND METHODS

Insulin resistance was assessed using the homeostasis model (HOMA-IR). Serum HCV-RNA level (bDNA) and subtypes of HCV (LiPA) were determined for all patients.

RESULTS

Insulin resistance (HOMA-IR >3) was present in 105 patients (46%), and was associated with: age >45 years (OR, 2.614; 95% CI, 1.316 to 5.194), body mass index (BMI) >25 kg/m(2) (OR, 2.105; 95% CI, 1.048 to 4.229), serum HCV-RNA >800 000 IU/ml (OR, 3.143; 95% CI, 1.503 to 6.574), severe fibrosis (OR, 2.657; 95% CI, 1.214 to 5.818), and steatosis >30% (OR, 2.488; 95% CI, 1.105 to 5.602). Severe fibrosis was present in 67 patients (29%) and was associated with Egyptian origin (OR, 5.872; 95% CI, 2.747 to 12.553), excessive alcohol intake (OR, 5.311; 95% CI, 1.287 to 21.924), and HOMA-IR >3 (OR, 3.864; 95% CI, 1.859 to 8.034). 108 patients received a 48 week course of peginterferon plus ribavirin. SVR (undetectable serum HCV-RNA (TMA) 24 weeks after treatment stopping) was achieved in 59 patients (55%) and was associated with Egyptian origin (OR, 13.119; 95% CI, 3.089 to 55.706), HOMA-IR <2 (OR, 5.314; 95% CI, 1.953 to 14.459), and non-severe fibrosis (OR, 8.059; 95% CI, 2.512 to 25.855).

CONCLUSION

Insulin resistance and geographical origin are major predictors of liver fibrosis and response to peginterferon and ribavirin in HCV-4 patients. Insulin resistance is frequently encountered in these patients, and correlated independently with serum HCV-RNA.

[Treatment of chronic hepatitis B]

SUMMARY

In recent years, marked progress has been made in the treatment of chronic hepatitis B. Several agents have been approved: interferon alpha-(IFN), pegylated interferon alpha2a (PEG-IFN alpha2a), lamivudine, adefovir, entecavir, telbivudine and recently, tenofovir. Each drug has advantages and limitations. IFN and PEG-IFN alpha2a have the advantage of inducing a sustained virologic response after a defined, limited course of treatment. However, these drugs are only effective in a minority of patients and have frequent side effects. Analogues have the advantage of being administered orally, with good safety profiles and a potent antiviral effect. However, these drugs need to be administered indefinitely since withdrawal of therapy is generally associated with reactivation, and a sustained response is uncommon except in HBeAg positive patients who develop HBe seroconversion. In case of HBe seroconversion, therapy should usually be continued for at least another 24 weeks. The efficacy of lamivudine is limited by the emergence of lamivudine-resistant HBV. Adefovir is associated with a moderate incidence of resistance but its antiviral effect is not optimal. Entecavir has shown to be more effective with a favourable safety profile and a low incidence of resistance. Telbivudine is more potent and has a lower rate of resistance than lamivudine but the resistance rate is significantly higher than other approved drugs. Tenofovir has a potent antiviral effect with a good resistance profile. The future of chronic hepatitis B therapy appears to be different drug combinations. Normally the advantage of drug combinations versus monotherapy should be additive or synergistic antiviral effects and a decrease in viral resistance. Unfortunately, there are few data available and none of the evaluated analogue combinations have been shown to be better than monotherapy. The only combination which has shown a synergistic effect is of pegylated interferon alpha2a with lamivudine. Therefore, combinations of pegylated interferon with the most potent analogues need to be evaluated. The ultimate goal of therapy is HBsAg seroconversion which is more often observed with interferon. Indeed, quantification of serum HBsAg will be a useful tool to predict the treatment outcome. More potent drugs and new combinations as well as understanding the mechanisms of viral resistance should be evaluated to improve the efficacy of treatment.

Liver gene expression signature to predict response to pegylated interferon plus ribavirin combination therapy in patients with chronic hepatitis C

BACKGROUND AND AIMS

The gold standard treatment of chronic hepatitis C (CHC) is combined pegylated interferon and ribavirin. Considering side effects and treatment cost, prediction of treatment response before therapy is important. The aim of this study was to identify a liver gene signature to predict sustained virological response in patients with CHC.

METHODS

Group A (training set) comprised 40 patients with CHC including 14 non-responders (NRs) and 26 sustained virological responders (SVRs). Group B (validation set) comprised 29 patients including 9 NRs and 20 SVRs. Eleven responder-relapsers were also included. A total of 58 genes associated with liver gene expression dysregulation during CHC were selected from the literature. Real-time quantitative RT-PCR assays were used to analyse the mRNA expression of these 58 selected genes in liver biopsy specimens taken from the patients before treatment.

RESULTS

From the Group A data, three genes whose expression was significantly increased in NRs compared with SVRs were identified: IFI-6-16/G1P3, IFI27 and ISG15/G1P2. These three genes also showed significant differences in their expression profiles between NRs and SVRs in the independent sample (Group B). Supervised class prediction analysis identified a two-gene (IFI27 and CXCL9) signature, which accurately predicted treatment response in 79.3% (23/29) of patients from the validation set (Group B), with a predictive accuracy of 100% (9/9) and of 70% (14/20) in NRs and SVRs, respectively. The expression profiles of responder-relapsers did not differ significantly from those of NRs and SVRs, and 73% (8/11) of them were predicted as SVRs with the two-gene classifier.

CONCLUSION

NRs and SVRs have different liver gene expression profiles before treatment. The most notable changes occurred mainly in interferon-stimulated genes. Treatment response could be predicted with a two-gene signature (IFI27 and CXCL9).

Management of chronic hepatitis C

Chronic hepatitis C is a major cause of cirrhosis and primary liver cancer (hepatocellular carcinoma). Decompensated cirrhosis or hepatocellular carcinoma secondary to hepatitis C is the first cause of liver transplantation in Europe and in the United States. The prognosis of chronic hepatitis C depends on the progression of fibrosis which determines the risk of developing cirrhosis and its complications. Knowledge of the natural history and the factors associated with the progression of fibrosis is essential for the patient's management. The risk of the progression of fibrosis is difficult to predict in one particular patient. Liver biopsy remains the best test to evaluate the severity of fibrosis, determine its prognosis and discuss the therapeutic options. At present, in a patient with hepatitis C, combined therapy associating pegylated alpha interferon and ribavirin results in a sustained response in approximately 55% of cases. Based on existing results, the sustained virological response with this treatment option appears to be long lasting, to be associated with a histological benefit and is also probably associated with a reduction in the risk of cirrhosis and hepatocellular carcinoma. The management of hepatitis C virus infections must include better knowledge of the natural history of the disease and existing available antiviral treatments (pegylated interferon and ribavirin) as well as in depth knowledge of the aims of treatment, the results obtained, the predictive factors of response and side effects. With close follow-up, doses can be rapidly modified and erythropoietin more frequently administered; new molecules may also be developed in this context. This paper will discuss the natural history, the factors associated with the progression of fibrosis, the predictive factors of response to treatment, and existing and future treatments for hepatitis C.

Quantitative measurement of hepatitis C virus core antigen is affected by the presence of cryoglobulins

Mixed cryoglobulinaemia is associated strikingly with HCV infection. The aim of this study was to assess whether the adherence to proper methods of collecting samples for cryoglobulin detection was critical or not on virological parameters in hepatitis C virus (HCV) patients. We studied 56 consecutive patients. Blood samples were collected using a conventional method and a blood collection method at 37 degrees C adapted to cryoglobulin detection. HCV core antigen and HCV RNA were measured in sera and cryoglobulins issued from both blood collection methods. In cryoglobulin-positive patients, serum concentrations of HCV core antigen, but not that of HCV RNA, were significantly higher when a conventional method was used, compared to a blood collection method at 37 degrees C (P = 0.001). In the cryoprecipitates, concentration of HCV core antigen was optimum when the blood collection method at 37 degrees C, rather than the conventional method, was applied for cryoglobulin detection (P < 10(-4)). The recovery of HCV core antigen in the cryoprecipitate was improved when cryoglobulins were isolated using the blood collection method at 37 degrees C rather than the conventional method (P < 0.001). HCV parameter measurements and cryoglobulin study should not be performed on the same serum samples due to the potential impact of blood collection methods on results.

Accurate model predicting sustained response at week 4 of therapy with pegylated interferon with ribavirin in patients with chronic hepatitis C

Current models used to predict response to peginterferon plus ribavirin treatment, based on viral decline during the first 12 weeks of therapy, have focused on creating an early stopping rule to avoid unnecessary prolongation of therapy. We developed a multivariate model that predicted sustained virological response and nonresponse at baseline and during the first 12 weeks of therapy using collected data from 186 unselected patients with chronic hepatitis C treated with peginterferon plus ribavirin. This model employed ordinal regression with similarity least squares technology to assign the probability of a given outcome. Model variables include sex, age, prior treatment status, genotype, baseline serum alanine aminotransferase levels, histologic necroinflammation and fibrosis scores and serum hepatitis C virus RNA concentration at baseline and weeks, 4, 8, and 12. A multivariate model demonstrated high performance values at all time points. At baseline, the model demonstrated a negative predictive value (NPV) and a positive predictive value (PPV) of 91% and 95%, respectively. At week 4, these values improved to 97% and 100%, respectively, with 95% sensitivity, 89% specificity and 93% accuracy. At week 4, the model was equally efficient for naïve or previously treated patients. Internal validation demonstrated 90% PPV, 94% NPV, 95% sensitivity, 88% specificity and 92% accuracy. A week 4 stopping rule for patients with chronic hepatitis C treated with peginterferon with ribavirin might be proposed by using the model developed in our study.

Medical therapy of patients affected by HBeAg-negative chronic hepatitis B

Five agents are currently approved for the treatment of chronic hepatitis B: standard interferon-alpha (IFN-alpha), pegylated interferon-alpha 2a (PEG-IFN-alpha 2a), lamivudine, adefovir and entecavir. Each agent has inherent limitations. IFN and PEG-IFN-alpha 2a are effective in a minority of patients and have frequent side effects that limit their tolerability. The efficacy of lamivudine is limited by the emergence of drug-resistant hepatitis B virus (HBV) mutants, restricting its utility as a long-term therapy. Adefovir is well tolerated and associated with a low incidence of resistance but its antiviral effect is not optimal. Entecavir, which has been recently registered, has a more potent anti-viral effect but its long term efficacy and resistance profile is still not known. These antivirals induce a sustained response after withdrawal of therapy in only a minority of patients and therefore the treatment needs to be indefinitely administered in the majority of patients. After a brief summary of the natural history of chronic hepatitis B in order to understand the indications and the objectives of therapy, this review focuses on treatment of HBeAg-negative chronic hepatitis B with IFN and PEG-IFN-alpha 2a.

Treatment of chronic hepatitis B

In the last years, marked progress has been made in the treatment of chronic hepatitis B. The efficacy of lamivudine, the first nucleoside analogue available, is limited by the high incidence of resistance. Adefovir, which was recently approved has a comparable efficacy with a very low frequency of resistance. However, adefovir needs to be indefinitely administered as withdrawal of therapy is generally associated with reactivation and sustained response is uncommon. Recent large randomized controlled trials showed that PEG IFNs induce relatively high sustained response rates both in HBeAg positive and HBeAg negative chronic hepatitis B. So far, the combination of PEG IFN with lamivudine, used simultaneously, is disappointing in terms of short-term efficacy. However, long-term efficacy needs to be assessed and different schedules of combination (for example sequential) need to be evaluated. A number of nucleoside analogues, with favourable toxicity profiles and a promise of increased effectiveness against HBV, are at various stages of clinical development. Results of phase III trials of entecavir and emtricitabine confirmed their efficacy. However, while entecavir is associated with a low incidences of resistance, emtricitabine is associated with a relatively high incidence of resistance which limits its use as a monotherapy. The efficacy and safety of new and more potent drugs like telbivudine and clevudine need to be confirmed. The future of chronic hepatitis B therapy seems to be in the combination of different drugs. Ideally, the optimal drugs to combine would meet the following criteria: they should have different sites of action on HBV DNA replication, a potent antiviral effect, an excellent safety profile and they should induce a sustained response with a limited duration of therapy. Indeed, the concept of combination therapy has been recently developed in order to increase efficacy and to decrease the occurrence of viral resistance. However, so far few combinations have been evaluated. No combination therapy demonstrated a benefit as compared with monotherapy. More potent drugs and new combinations together with the understanding of the mechanisms of resistance to therapy are important challenges to improve the efficacy of treatment and decrease in the future the global burden related to chronic hepatitis B.

Safety and efficacy of peginterferon plus ribavirin in patients with chronic hepatitis C and bridging fibrosis or cirrhosis

The combination of pegylated interferon and ribavirin is the most effective therapy in patients with chronic hepatitis C. We evaluated this combination in unselected patients with bridging fibrosis or cirrhosis. Eighty patients were treated with peginterferon alpha-2b plus ribavirin. Hepatitis C virus serum RNA was monitored. Tolerance and safety were evaluated by the rate of treatment's discontinuation for any reason, and occurrence of serious clinical adverse events, respectively. Sustained virologic response (SVR) rate was 36.3% overall, and was observed in every group of patients except those who had previously failed to respond to the combination of interferon and ribavirin. No serious clinical adverse event occurred. Treatment was withdrawn in 18.7% of patients. Variables associated with discontinuation of treatment were low prothrombin index [OR: 1.16 (1.05;1.27)] and low body mass index [OR: 1.47 (1.12;1.92)]. Initial blood count abnormalities were not associated with cessation of treatment. Furthermore, early virologic response at week 8 and week 12 of treatment had similar predictive value for SVR. Combination therapy with peginterferon plus ribavirin seems effective in this group of patients, except in those who had previously failed to respond to the combination of interferon and ribavirin. This therapy is safe with appropriate monitoring, but tolerance seems worse in patients with the most advanced liver disease.

Natural history of hepatitis B

The natural course of hepatitis B virus (HBV) chronic infection is variable, ranging from an inactive HBsAg carrier state to a more or less progressive chronic hepatitis, potentially evolving to cirrhosis and hepatocellular carcinoma (HCC). Chronic hepatitis may present as typical HBeAg-positive chronic hepatitis B or HBeAg-negative chronic hepatitis B. HBeAg-positive chronic hepatitis is due to wild type HBV; it represents the early phase of chronic HBV infection. HBeAg-negative chronic hepatitis is due to a naturally occurring HBV variant with mutations in the precore or/and basic core promoter regions of the genome; it represents a late phase of chronic HBV infection. The latter form of the disease has been recognized as increasing in many countries within the last decade and it represents the majority of cases in many countries. HBeAg-negative chronic hepatitis B is generally associated with a more severe liver disease with a very low rate of spontaneous disease remission and a low sustained response rate to antiviral therapy. Longitudinal studies of patients with chronic hepatitis B indicate that, after diagnosis, the 5-year cumulative incidence of developing cirrhosis ranges from 8-20%. Morbidity and mortality in chronic hepatitis B are linked to evolution to cirrhosis or HCC. The 5-year cumulative incidence of hepatic decompensation is approximately 20%. The 5-year probability of survival is approximately 80-86% in patients with compensated cirrhosis. Patients with decompensated cirrhosis have a poor prognosis (14-35% probability of survival at 5 years). HBV-related end-stage liver disease or HCC are responsible for at least 500,000 deaths per year.

Long term clinical outcome of chronic hepatitis C patients with sustained virological response to interferon monotherapy

BACKGROUND

The key end point for treatment efficacy in chronic hepatitis C is absence of detectable virus at six months after treatment. However, the incidence of clinical events during long term follow up of patients with sustained virological response is still poorly documented and may differ between the Eastern and Western world.

AIMS

To assess clinical end points during long term follow up of European patients with a sustained virological response to interferon monotherapy.

METHODS

Meta-analysis of individual patient data from eight European protocolled follow up studies of interferon treatment for chronic hepatitis C.

RESULTS

A total of 286 sustained virological responders and 50 biochemical responders (detectable virus but normal alanine aminotransferase levels) were followed up for 59 months. Fifteen sustained virological responders (5.2%) had cirrhosis before treatment and 112 (39%) had genotype 1. The late virological relapse rate after five years of follow up was 4.7% (95% confidence interval (CI) 2.0-7.4) among sustained virological responders; all late relapses occurred within four years after treatment. Among sustained virological responders, the rate of decompensation after five years of follow up was 1.0% (95% CI 0.0-2.3) and none developed hepatocellular carcinoma (HCC). Survival was comparable with the general population, matched for age and sex, the standard mortality ratio being 1.4 (95% CI 0.3-2.5). Clinical outcome of patients with cirrhosis was similar to other sustained virological responders. For biochemical responders, the rates of development of decompensation and HCC during long term follow up were 9.1% (95% CI 0.5-17.7) and 7.1% (95% CI 0-15.0), respectively.

CONCLUSIONS

Five year survival of European sustained virological responders was similar to the overall population, matched for age and sex. No HCCs were detected during long term follow up.

Treatment of chronic hepatitis c

Since the discovering of the hepatitis C virus in 1989, the treatment of hepatitis C has considerably improved. Initially, with interferon alpha used as a single drug, the sustained virological response rate was below 20%. Then, with the use of combination therapy of interferon a with ribavirin, the response rate increased to 41%. More recently, combination of pegylated interferons with ribavirin give a response rate of about 54-63%. The long-term follow-up studies showed that sustained virological response is generally associated with clinical and histological improvement. The indication of therapy is mainly based on the results of the liver biopsy which is the best way to assess the prognosis of the liver disease. Therefore, treatment is indicated in patients with moderate or severe necroinflammation or fibrosis. The tolerability of combination therapy is relatively poor with a frequent flu-like syndrome and an impaired quality of life. Factors associated with a poor response to treatment are essentially genotype 1 and high viral load. To further improve the efficacy of therapy, different new drugs are under investigation (amantadine, cytokines). These drugs may be candidates for new combinations. In addition, intensive research is currently done for the development of inhibitors of viral enzymes (helicase, protease or polymerase) and anti-sense oligonucleotides, ribozymes and therapeutic vaccine.

Liver fibrosis is not associated with steatosis but with necroinflammation in French patients with chronic hepatitis C

BACKGROUND

In chronic hepatitis C, it has been suggested that steatosis could accelerate progression of fibrosis. However, results of the few published studies are controversial.

AIM

To determine the characteristics (epidemiological, biological, and histological) associated with steatosis and its relationship with liver lesions (grade of necroinflammation and stage of fibrosis) in patients with chronic hepatitis C.

METHODS

From November 2000 to July 2001, untreated consecutive adults with chronic hepatitis C admitted for liver biopsy were included in this study. On the day of liver biopsy, a questionnaire for risk factors was completed prospectively, and a blood sample was obtained for laboratory analysis.

RESULTS

Our study included 290 patients (143 men, 147 women). Mean body mass index (BMI) was 24 (3.8) kg/m(2). Proportions of patients with genotypes 1 and 3 were, respectively, 48% and 18%. A total of 135 patients (46.6%) had steatosis. Liver steatosis, in multivariate analysis, was associated with hepatitis C virus genotype 3, higher grade of necroinflammation, and higher BMI. There was no significant association between stage of fibrosis and liver steatosis. In multivariate analysis, high stage of fibrosis was associated with male sex, age over 50 years, high BMI, and high grade of necroinflammation.

CONCLUSION

In our population of patients with chronic hepatitis C, steatosis does not seem to be an important determinant of liver fibrosis. High grade of necroinflammation is associated with a high stage of fibrosis.

Second infection with a different hepatitis C virus genotype in a intravenous drug user during interferon therapy

The prevalence of antibodies against hepatitis C virus (anti-HCV) among intravenous drug users (IVDU) has consistently been very high. Cross challenge studies in chimpanzees provide evidence that reinfection with different HCV strains may occur. In humans, reinfection with different HCV strains has been reported in multitransfused haemophiliacs and recently in IVDU but no case has been reported while on interferon (IFN) therapy. We report on a 22 year old woman who was treated with IFN alpha for HCV genotype 3a chronic infection. At six months, HCV RNA was undetectable by reverse transcription-polymerase chain reaction. In October 1997, while still on IFN, she developed an acute hepatitis after an intravenous drug injection and HCV genotype 1a infection was identified using genotyping and sequencing methods. IFN therapy was continued until August 1998, and in January 1999 HCV-RNA was not detectable. Our case indicates that the previous HCV infection might have prevented development of chronicity. An alternative explanation is that IFN, while not preventing acute hepatitis C, may prevent chronicity. The risk of multiple infection in IVDU underlines the need for preventive strategies.