Intra-CSF AAV9 and AAVrh10 Administration in Nonhuman Primates: Promising Routes and Vectors for Which Neurological Diseases?

The identification of the most efficient method for whole central nervous system targeting that is translatable to humans and the safest route of adeno-associated virus (AAV) administration is a major concern for future applications in clinics. Additionally, as many AAV serotypes were identified for gene introduction into the brain and the spinal cord, another key to human gene-therapy success is to determine the most efficient serotype. In this study, we compared lumbar intrathecal administration through catheter implantation and intracerebroventricular administration in the cynomolgus macaque. We also evaluated and compared two AAV serotypes that are currently used in clinical trials: AAV9 and AAVrh10. We demonstrated that AAV9 lumbar intrathecal delivery using a catheter achieved consistent transgene expression in the motor neurons of the spinal cord and in the neurons/glial cells of several brain regions, whereas AAV9 intracerebroventricular delivery led to a consistent transgene expression in the brain. In contrast, AAVrh10 lumbar intrathecal delivery led to rare motor neuron targeting. Finally, we found that AAV9 efficiently targets respiratory and skeletal muscles after injection into the cerebrospinal fluid (CSF), which represents an outstanding new property that can be useful for the treatment of diseases affecting both the central nervous system and muscle.

Microvesicles in hepatic and peripheral vein can predict nonresponse to corticosteroid therapy in severe alcoholic hepatitis

BACKGROUND

Severe alcoholic hepatitis patients have high mortality and limited response to corticosteroids. Microvesicles reflect cellular stress and disease conditions.

AIMS

To investigate whether microvesicles are associated with severity, response to steroid therapy and inflammation in severe alcoholic hepatitis.

METHODS

Microvesicles originating from different cells were studied pre-therapy in 101 patients; (71 responder to corticosteroid therapy and 30 nonresponders) and 20 healthy controls. Microvesicles and cells were determined in peripheral and hepatic vein samples using flow cytometry and correlated with outcomes. Inflammatory signalling pathways and functional alterations of immune cells after stimulation with microvesicles were also investigated.

RESULTS

Microvesicles mean levels were higher in nonresponders for T cells (CD3⁺ CD4⁺ ; 10.1 MV/μL vs 5.4; P = 0.06), macrophages (CD68⁺ CD11b⁺ ; 136.5 vs 121.9 MV/μL; P = 0.01), haematopoietic stem-cells (CD45⁺ CD34⁺ ; 116.8 vs 13.4 MV/μL; P = 0.0001) and hepatocytes (ASGPR⁺ ; 470 vs 361 MV/μL; P = 0.01); the latter two predicting steroid nonresponse in 94% patients at baseline in peripheral plasma. Microvesicle levels correlated with histological and liver disease severity indices. Whereas, in non-responders hepatic vein CD34+ cells were lower (P = 0.02), the CD34+ microvesicles there from were higher (P = 0.04), thus suggesting impaired regeneration. Also, microvesicles of 0.2-0.4 μm size were higher in nonresponders (P < 0.03) at baseline. Microvesicles from patients trigger more (P = 0.04) ROS generation, TNF-α production (P = 0.04) and up-regulate pro-inflammatory cytokine related genes in neutrophils in vitro.

CONCLUSIONS

Pre-therapy peripheral plasma levels of CD34⁺ and ASGPR⁺ microvesicles are reliable non-invasive markers of steroid nonresponse and mortality in patients with severe alcoholic hepatitis.

Liver failure determines the outcome in patients of acute-on-chronic liver failure (ACLF): comparison of APASL ACLF research consortium (AARC) and CLIF-SOFA models

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is a progressive disease associated with rapid clinical worsening and high mortality. Early prediction of mortality and intervention can improve patient outcomes. We aimed to develop a dynamic prognostic model and compare it with the existing models.

METHODS

A total of 1402 ACLF patients, enrolled in the APASL-ACLF Research Consortium (AARC) with 90-day follow-up, were analyzed. An ACLF score was developed in a derivation cohort (n = 480) and was validated (n = 922).

RESULTS

The overall survival of ACLF patients at 28 days was 51.7%, with a median of 26.3 days. Five baseline variables, total bilirubin, creatinine, serum lactate, INR and hepatic encephalopathy, were found to be independent predictors of mortality, with AUROC in derivation and validation cohorts being 0.80 and 0.78, respectively. AARC-ACLF score (range 5-15) was found to be superior to MELD and CLIF SOFA scores in predicting mortality with an AUROC of 0.80. The point scores were categorized into grades of liver failure (Gr I: 5-7; II: 8-10; and III: 11-15 points) with 28-day cumulative mortalities of 12.7, 44.5 and 85.9%, respectively. The mortality risk could be dynamically calculated as, with each unit increase in AARC-ACLF score above 10, the risk increased by 20%. A score of ≥11 at baseline or persisting in the first week was often seen among nonsurvivors (p = 0.001).

CONCLUSIONS

The AARC-ACLF score is easy to use, dynamic and reliable, and superior to the existing prediction models. It can reliably predict the need for interventions, such as liver transplant, within the first week.

Neutrophil gelatinase-associated lipocalin is a biomarker of acute-on-chronic liver failure and prognosis in cirrhosis

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in cirrhosis characterized by organ failure(s) and high mortality rate. There are no biomarkers of ACLF. The LCN2 gene and its product, neutrophil gelatinase-associated lipocalin (NGAL), are upregulated in experimental models of liver injury and cultured hepatocytes as a result of injury by toxins or proinflammatory cytokines, particularly Interleukin-6. The aim of this study was to investigate whether NGAL could be a biomarker of ACLF and whether LCN2 gene may be upregulated in the liver in ACLF.

METHODS

We analyzed urine and plasma NGAL levels in 716 patients hospitalized for complications of cirrhosis, 148 with ACLF. LCN2 expression was assessed in liver biopsies from 29 additional patients with decompensated cirrhosis with and without ACLF.

RESULTS

Urine NGAL was markedly increased in ACLF vs. no ACLF patients (108(35-400) vs. 29(12-73)μg/g creatinine; p<0.001) and was an independent predictive factor of ACLF; the independent association persisted after adjustment for kidney function or exclusion of variables present in ACLF definition. Urine NGAL was also an independent predictive factor of 28day transplant-free mortality together with MELD score and leukocyte count (AUROC 0.88(0.83-0.92)). Urine NGAL improved significantly the accuracy of MELD in predicting prognosis. The LCN2 gene was markedly upregulated in the liver of patients with ACLF. Gene expression correlated directly with serum bilirubin and INR (r=0.79; p<0.001 and r=0.67; p<0.001), MELD (r=0.68; p<0.001) and Interleukin-6 (r=0.65; p<0.001).

CONCLUSIONS

NGAL is a biomarker of ACLF and prognosis and correlates with liver failure and systemic inflammation. There is remarkable overexpression of LCN2 gene in the liver in ACLF syndrome.

LAY SUMMARY

Urine NGAL is a biomarker of acute-on-chronic liver failure (ACLF). NGAL is a protein that may be expressed in several tissues in response to injury. The protein is filtered by the kidneys due to its small size and can be measured in the urine. Ariza, Graupera and colleagues found in a series of 716 patients with cirrhosis that urine NGAL was markedly increased in patients with ACLF and correlated with prognosis. Moreover, gene coding NGAL was markedly overexpressed in the liver tissue in ACLF.

The use of an exoskeleton to investigate the self advantage phenomenon

This paper presents an upper extremity exoskeleton with an original application in neuroscience. The novelty of this study is the investigation of the self-advantage phenomenon under various experimental conditions. Usually this kind of experiments lies only on human visual ability to explicitly and/or implicitly recognize their own arm movements. Using an exoskeleton to replay recorded trajectories allows to give another perspective to the previous studies in including the proprioceptive ability of humans. Twelve healthy subjects were involved in this study. The results show that the self advantage phenomenon is even more present in the implicit tasks.

Pneumatic evoked potential. Sensory or auditive potential?

STUDY AIM

In this study, evoked potentials (EPs) to a pneumatic, innocuous, and calibrated stimulation of the skin were recorded in 22 volunteers.

METHODS

Air-puff stimuli were delivered through a home-made device (INSA de Lyon, Laboratoire Ampère, CHU de Saint-Étienne, France) synchronized with an EEG recording (Micromed(®)).

RESULTS

A reproducible EP was recorded in 18 out of 22 subjects (82% of cases) with a mean latency of about 120-130ms, and maximal amplitude at Cz. This EP actually consisted of two components, an auditory and a somatosensory one. Indeed, it was significantly decreased in amplitude, but did not disappear, when the noise generated by the air-puff was masked. We also verified that a stimulation close to the skin but not perceived by the subject was not associated with any EP. Conduction velocity between hand and shoulder was calculated around 25m/s.

CONCLUSIONS

This preliminary study demonstrates that pneumatic EPs can be recorded in normal volunteers.

[Community pharmacist and vaccination: actuality and opportunity]

Improving the vaccinal policy has become a major stake in France as in many other developed countries. The neglect of vaccination strategies by citizens has complex and multiple causes. Some are directly linked with recent media controversies about vaccination and with a global lack of confidence toward producers and regulators. Other causes are directly linked with individual behaviors, professional practices and primary care organization. Community pharmacists have a good observing position of this phenomenon, as they are prepositioned on the territory, in constant contact with both outpatients and healthy people. Pharmacist's sociological and technical observations appear to be useful in designing new approaches for improving vaccinal strategies. While the 2012-2017 "vaccine policy" should emphasize the central role of general practitioners in France, these observations invite to develop innovative collaboration with pharmacists in the search of a better vaccine coverage.

Gravity compensation of an upper extremity exoskeleton

This paper presents a new gravity compensation method for an upper extremity exoskeleton mounted on a wheel chair. This new device is dedicated to regular and efficient rehabilitation training for post-stroke and injured people without the continuous presence of a therapist. The exoskeleton is a wearable robotic device attached to the human arm. The user provides information signals to the controller by means of the force sensors around the wrist and the arm, and the robot controller generates the appropriate control signals for different training strategies and paradigms. This upper extremity exoskeleton covers four basic degrees of freedom of the shoulder and the elbow joints with three additional adaptability degrees of freedom in order to match the arm anatomy of different users. For comfortable and efficient rehabilitation, a new heuristic method have been studied and applied on our prototype in order to calculate the gravity compensation model without the need to identify the mass parameters. It is based on the geometric model of the robot and accurate torque measurements of the prototype's actuators in a set of specifically chosen joint positions. The weight effect has been successfully compensated so that the user can move his arm freely while wearing the exoskeleton without feeling its mass.

Molecular epidemiology of Escherichia coli bacteremia in liver transplant recipients

The characteristics of Escherichia coli strains causing bacteremia in profoundly immunosuppressed patients such as transplant recipients are undefined. The phylogenetic group and the virulence genotype of 57 distinct E. coli strains that caused bacteremia in 53 liver transplant recipients were investigated, and the association of these characteristics with host factors and in-hospital mortality was examined. Phylogenetic groups A, B1, B2, and D accounted for 39%, 10%, 25%, and 26% of the isolates, respectively. The most prevalent virulence genes were fyuA (yersiniabactin system: 70%) and iutA (aerobactin system: 63%), whereas hlyA (alpha-hemolysin) and cnf1 (cytotoxic necrotizing factor 1) occurred in only 14% and 12% of isolates, respectively. Most virulence genes were significantly more prevalent among group B2 and D isolates, vs. group A and B1 isolates. The overall rate of in-hospital mortality after E. coli bacteremia was 20%. Predictors of mortality included onset of bacteremia within 30 days of transplantation or during the intensive care unit stay, and non-urinary source and cutaneous source, but not E. coli phylogenetic group or virulence profile. Compared with historical E. coli bloodstream isolates from non-transplant patients, those from liver transplant recipients are characterized by a higher prevalence of groups A and B1 isolates and reduced virulence gene content. This finding can be explained by the severely immunocompromised status of the patients and the predominance of abdominal-source bacteremic episodes. Time of onset and source of bacteremia, not bacterial characteristics, predict mortality.

Three-dimensional gesture comparison using curvature analysis of position and orientation

This paper describes a new analysis method dedicated to the comparison of human gestures. The orientations and the positions of the gestures are first digitized using active 3D sensors and then compared to a 6-D template using curvature analysis. The proposed algorithm first starts by computing the invariant curvature of 3D position and orientation of a surgical tool using Frenet-Serret frames in 3D and quaternion space. The resulting curvature calculation is matched and compared to the template using a Dynamic Time Warping method. The proposed method is invariant to sensor position and orientation. An experimental study shows the efficiency of the new algorithm for an application in obstetrics, where the aim is to compare forceps blade placements between a senior medical doctor and a novice.

Evaluation of medical gestures based on a global performance index

This paper presents a method to evaluate medical gestures. The objective is to objectively assess a gesture carried out by novice doctors. The proposed method is based on the study of the curvature of the 3D gesture and provide a global performance index for one manipulation. The study of the number of peaks on the curvature indicates if the gesture is smooth or not. The application is the obstetric gestures linked to the forceps use but the method can be applied to different gestures without loss of generality. Seven residents carried out 30 forceps blade placements. The results clearly show a difference between the gestures carried out. This highlights the difficulty of the gesture according to the fetal head presentation.

[Progress in portal hypertension]

In patients with portal hypertension due to cirrhosis, the mechanisms responsible for circulatory modifications are well-known. An elevation in intrahepatic vascular resistance related to a hepatic endothelin hyperproduction and an arterial nitric oxide (NO) hyperproduction. The presence and the degree of portal hypertension might be determined by the measurement of the hepatic venous pressure gradient but non-invasive technique as FibroTest or FibroScan might be useful to estimate the presence of severe portal hypertension. Numerous substances decrease portal pressure either by reducing hepatic vascular resistance or by reducing portal tributary blood flow. The combination of both types of substances is probably the best pharmacological treatment of portal hypertension but further hemodynamic and clinical studies are needed.

Gene expression and hepatitis C virus infection

Hepatitis C virus (HCV) is a major cause of chronic liver disease, with about 170 million people infected worldwide. Up to 70% of patients will have persistent infection after inoculation, making this disease a significant cause of morbidity and mortality. The severity of disease varies widely, from asymptomatic chronic infection to cirrhosis and hepatocellular carcinoma. Since the discovery of HCV, the treatment of hepatitis C has considerably improved. Recently, combination of pegylated interferons with ribavirin gives a response rate of about 55%. Treatment is indicated in patients with moderate or severe fibrosis. The tolerability of combination treatment is relatively poor, with a frequent flu-like syndrome and an impaired quality of life. In addition to viral and environmental behavioural factors, host genetic diversity is believed to contribute to the spectrum of clinical outcomes in HCV infection. The sequencing of the human genome, together with the development of high-throughput technologies that measure the function of the genome, have afforded unique opportunities to develop profiles that can distinguish, identify and classify discrete subsets of disease, predict the disease outcome or predict the response to treatment. This paper reviews the published literature on gene expression associated with HCV infection (HCV infection, fibrosis progression), and also according to response to treatment.

Evaluation of obstetric gestures: an approach based on the curvature of quaternions

This paper presents a method to evaluate a gesture carried out by a resident obstetrician by comparing it to a gesture carried out by an expert obstetrician. The studied gesture is the forceps blade placement. Resident paths were recorded on a childbirth simulator while placing forceps blades instrumented with six degrees of freedom sensors. The path is characterized by the positions and the orientations. In this paper we particularly focus on the orientations. Forceps orientations are expressed in the quaternion unit space and the curvature of quaternion path is compared by correlation to a reference defined by an expert. Residents have been trained on a simulator and their gestures are evaluated by comparing their orientation path curvatures to reference path curvatures. Quantitative results confirm the qualitative analysis, residents become more similar to the reference while training on simulator.

Genetic background of Escherichia coli isolates from patients with spontaneous bacterial peritonitis: relationship with host factors and prognosis

Spontaneous bacterial peritonitis (SBP) is a severe complication in patients with cirrhosis and ascites. It is predominantly caused by Escherichia coli. The phylogenetic group and virulence genotype of E. coli isolates causing SBP were investigated, and the association of these characteristics with host factors and prognosis was examined. Seventy-six episodes of E. coli SBP that occurred over a 9-year period were studied. The phylogenetic group of the isolates and the presence of 36 virulence factor genes were investigated. The influence of bacterial and host factors on in-hospital mortality was assessed by multiple logistic regression. Phylogenetic groups A, B1, B2 and D were found in 26%, 4%, 46% and 24% of the isolates, respectively. Virulence factor genes were more frequent in B2 isolates than in non-B2 isolates (mean virulence score 15.4 vs. 7.3, p <10(-4)). Ciprofloxacin resistance was significantly associated with non-B2 groups and a low virulence score. Host factors independently associated with a shift from B2 to non-B2 isolates were norfloxacin prophylaxis (OR 13.01, p 0.0213) and prothrombin ratio (OR 1.04 for a 10% decrease, p 0.0211). The model for end-stage liver disease (MELD) score (OR 1.83, p 0.0007) and hospital-acquired SBP (OR 4.13, p 0.0247) were independent predictors of in-hospital mortality. In contrast, outcome was not influenced by the phylogenetic group or the virulence profile. These findings indicate that the characteristics of E. coli isolates causing SBP vary with the severity of liver disease and with fluoroquinolone prophylaxis. Host factors are more important than bacterial factors in predicting in-hospital mortality.

Characterization of oxidized low-density lipoprotein-induced hormesis-like effects in osteoblastic cells

Epidemiological studies indicate that patients suffering from atherosclerosis are predisposed to develop osteoporosis. Atherogenic determinants such as oxidized low-density lipoprotein (oxLDL) particles have been shown both to stimulate the proliferation and promote apoptosis of bone-forming osteoblasts. Given such opposite responses, we characterized the oxLDL-induced hormesis-like effects in osteoblasts. Biphasic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reductive activity responses were induced by oxLDL where low concentrations (10-50 microg/ml) increased and high concentrations (from 150 microg/ml) reduced the MTT activity. Cell proliferation stimulation by oxLDL partially accounted for the increased MTT activity. No alteration of mitochondria mass was noticed, whereas low concentrations of oxLDL induced mitochondria hyperpolarization and increased the cellular levels of reactive oxygen species (ROS). The oxLDL-induced MTT activity was not related to intracellular ROS levels. OxLDL increased NAD(P)H-associated cellular fluorescence and flavoenzyme inhibitor diphenyleneiodonium reduced basal and oxLDL-induced MTT activity, suggesting an enhancement of NAD(P)H-dependent cellular reduction potential. Low concentrations of oxLDL reduced cellular thiol content and increased metallothionein expression, suggesting the induction of compensatory mechanisms for the maintenance of cell redox state. These concentrations of oxLDL reduced osteoblast alkaline phosphatase activity and cell migration. Our results indicate that oxLDL particles cause hormesis-like response with the stimulation of both proliferation and cellular NAD(P)H-dependent reduction potential by low concentrations, whereas high concentrations lead to reduction of MTT activity associated with the cell death. Given the effects of low concentrations of oxLDL on osteoblast functions, oxLDL may contribute to the impairment of bone remodeling equilibrium.

Incidence and characteristics of type 2 hepatorenal syndrome in patients with cirrhosis and refractory ascites

BACKGROUND AND AIM

Type 2 hepatorenal syndrome (HRS) is a well described progressive impairment of renal function in patients with cirrhosis but its natural history, especially in patients with refractory ascites, is not well known. The aim of this study was to assess the incidence, predictive factors and outcome of type 2 HRS in patients with cirrhosis and refractory ascites.

PATIENTS AND METHODS

Thirty patients with refractory ascites were followed-up for 17.5 +/- 26.3 months. The clinical characteristics, biological findings and outcome were analysed. The occurrence of renal dysfunction, and type 2 HRS in particular, was systematically analysed.

RESULTS

Twenty-five patients (83.3%) developed renal dysfunction. Type 2 HRS was diagnosed in 16 patients (53.3%). Patients with type 2 HRS were older than patients without (64.8 +/- 9.1 yr vs 52.8 +/- 9.0 yr ; p < 0.001). All the others studied variables were similar between type 2 HRS and non-type 2 HRS patients. There was no significant difference in the overall probability of survival between these 2 groups.

CONCLUSIONS

In patients with cirrhosis and refractory ascites, the development of type 2 HRS is frequent but does not occur in more severe liver disease and does not affect prognosis.

Capacitative calcium entry and proliferation of human osteoblast-like MG-63 cells

Adult bone tissue is continuously being remodelled and bone mass is maintained by a balance between osteoclastic bone resorption and osteoblastic bone formation. Alteration of osteoblastic cell proliferation may account in part for lack of balance between these two processes in bone loss of osteoporosis. There is calcium (Ca2+) control in numerous cellular functions; however, involvement of capacitative Ca2+ entry (CCE) in proliferation of bone cells is less well investigated.

OBJECTIVES

The study described here was aimed to investigate roles of CCE in the proliferation of osteoblast-like MG-63 cells.

MATERIALS AND METHODS

Pharmacological characterizations of CCE were undertaken in parallel, with evaluation of the expression of transient receptor potential canonical (TRPC) channels and of cell proliferation.

RESULTS

Intracellular Ca2+ store depletion by thapsigargin induced CCE in MG-63 cells; this was characterized by a rapid transient increase of intracellular Ca2+ followed by significant CCE, induced by conditions that stimulated cell proliferation, namely serum and platelet-derived growth factor. Inhibitors of store-operated Ca2+ channels (2-APB and SKF-96365) prevented CCE, while voltage-dependent Ca2+ channel blockers had no effect. Expression of various TRPC channels was shown in the cells, some having been shown to be responsible for CCE. Voltage-dependent Ca2+ channel blockers had no effect on osteoblast proliferation while thapsigargin, 2-APB and SKF-96395, inhibited it. Cell cycle analysis showed that 2-APB and SKF-96395 lengthen the S and G2/M phases, which would account for the reduction in cell proliferation.

CONCLUSIONS

Our results indicate that CCE, likely attributed to the activation of TRPCs, might be the main route for Ca2+ influx involved in osteoblast proliferation.

Importance of melastatin-like transient receptor potential 7 and cations (magnesium, calcium) in human osteoblast-like cell proliferation

Bone tissue in the adult is continuously being remodelled, and overall bone mass is maintained constant by the balance between osteoclastic bone resorption and osteoblastic bone formation. Adequate osteoblastic proliferation is essential for both appropriate formation and for regulation of resorption, and thereby the maintenance of bone remodelling equilibrium.

OBJECTIVES

Here, we have investigated the roles of melastatin-like transient receptor potential 6 and 7 (TRPM6, TRPM7), which are calcium (Ca2+) and magnesium (Mg2+) conducting channels, during proliferation of human osteoblasts.

RESULTS

Genetic expression of TRPM6 and TRPM7 was shown in human osteoblast-like MG-63, SaOS and U2-OS cells, and reduction of extracellular Mg2+ or Ca2+ led to a decrease of cell proliferation. Concomitant reduction of both ions further accentuated reduction of cell proliferation. Expression of TRPM7 channels was increased under conditions of reduced extracellular Mg2+ and Ca2+ levels whereas expression of TRPM6 was not modified, suggesting compensatory mechanisms afforded by TRPM7 in order to maintain intracellular ion homeostasis. Pre-incubation of cells in reduced extracellular Mg2+ conditions led to activation of Ca2+ and Mg2+ influx. Reduction of TRPM7 expression by specific siRNA prevented latter influx and inhibited cell proliferation.

CONCLUSIONS

Our results indicate that extracellular Mg2+ and Ca2+ deficiency reduces the proliferation of human osteoblastic cells. Expression and activity of TRPM7 is modulated by extracellular Mg2+ and Ca2+ availability, indicating that TRPM7 channels are involved in intracellular ion homeostasis and proliferation of osteoblasts.

Design of a medical simulator for subcutaneous contraceptive implant insertion

New contraceptive methods like the subcutaneous implant offers a new kind of comfort for women with an efficiency similar to the contraceptive pill. Unfortunately, the few numbers of unintended pregnancies that have been reported, are generally due to a bad insertion of the implant. In order to give more security to patients, we have designed, in close collaboration with physicians, a new kind of medical simulator. This simulator can be used for two purposes: one for training novice physicians in the correct gesture and the other for doctor certification which will help to determine if they are capable of inserting the implant in vivo. This paper describes the approach which has led to the design of this simulator. It describes its functionalities, its several components but also methods used to analyze the gesture of the implant insertion inside the patient. Finally, first experimental results are reported and discussed.

Relationship between the Fibrotest and portal hypertension in patients with liver disease

BACKGROUND

The best technique to estimate portal hypertension (PHT) is to measure the hepatic venous pressure gradient (HVPG), which is an invasive method.

AIM

To assess the relationship between the Fibrotest (Biopredictive, Paris, France) and the presence and degree of PHT in patients with liver disease, and to determine if the Fibrotest can diagnose severe PHT, defined by HVPG >or= 12 mmHg, in cirrhotic patients.

METHODS

Patients who underwent a transjugular liver biopsy were prospectively included. HVPG was measured, and classification of histological lesions assessed. The same day, blood samples for Fibrotest were performed.

RESULTS

A total of 130 patients were included (no or minimal fibrosis: 12%, moderate fibrosis 17%, cirrhosis 71%). There was a significant correlation between Fibrotest and HVPG (Pearson correlation coefficient = 0.58, P < 0.0001), also weaker in cirrhotic patients (Pearson correlation coefficient = 0.24, P = 0.02). In cirrhotic patients, Fibrotest was significantly higher when there was a severe PHT (0.87 +/- 0.15 vs. 0.73 +/- 0.14, respectively, P = 0.02). The areas under the receiver operating characteristic curves for the diagnosis of severe PHT was 0.79 +/- 0.07, not different from that of platelets and Child-Pugh score.

CONCLUSION

In patients with liver disease or cirrhosis, Fibrotest is correlated with the presence and degree of PHT. Other studies are needed to confirm these results, especially in non-decompensated cirrhotic patients.

Evaluation of obstetric gestures: an approach based on the curvature of 3-D positions

This paper presents a method to evaluate a gesture carried out by a resident obstetrician doctors by comparing it to a gesture carried out by an expert obstetrician doctors. The studied gesture is the forceps blade placement. Residents were recorded on a childbirth simulator while placing forceps blades. Their paths were compared in order to evaluate how similar they are to a reference path defined by an expert. The comparison method is developed with respect to expert requests: time independence and in considering the whole set of data and not only particular points. In order to respect these requests, the developed method lies on the correlation coefficient between the path curvatures. Residents have been trained on a simulator and their gestures were evaluated by comparing their path curvatures to reference path curvatures. Quantitative results confirm the qualitative analysis, residents become more similar to the reference while training on simulator.

[Obstetrical forceps: yesterday, today and tomorrow. Toward a new classification of obstetrical forceps]

OBJECTIVE

Obstetrical forceps are used worldwide since more than 400 years. In 2003 forceps deliveries accounted for 6.3% of all deliveries of the AURORE Grand-Lyon perinatal network. Although more than 400 different forceps have been described, obstetrics handbooks neither describe experimental forceps nor provide any chapter dedicated to instrumental delivery training. Our aim was to provide junior obstetricians with information that will allow them to select the best instrument and to let them know about experimental as well as pedagogic forceps.

PATIENTS AND METHODS

International literature review using the terms "forceps" and "delivery" and a four year experimental work involving a close collaboration between obstetricians and biomechanics of the INSA engineering school.

RESULTS

Two instruments are presented as well as a new forceps classification.

DISCUSSION AND CONCLUSION

This classification distinguishes between three types of forceps: operational forceps designed to delivers neonates, experimental forceps designed to study biomechanics and training forceps designed for resident training. For the first time the classic blind forceps procedure is transformed in a full screen real time procedure.

Rapidité d’extraction respective des césariennes et des forceps réalisés en urgence

AIM

Comparison of the decision to delivery interval in cases of forceps delivery and in cases of cesarean sections.

MATERIAL AND METHOD

A retrospective analysis was performed on 137 cases of forceps deliver (n = 63) and cesarean section (n = 74) indicated for abnormal fetal heart rhythm. All cases were observed in a level 3 maternity unit between October 2003 and August 2004.

RESULTS

The mean decision-to-delivery interval was significantly shorter in the forceps group (14.84 min +/- 6.54 versus 29.31 min +/- 11.79 p < 0.0001). Maternal and neonatal morbidity were comparable.

CONCLUSION

This study suggest that once the fetal head is engaged, forceps delivery can significantly reduced the decision-to-delivery interval.

Sepsis in cirrhosis: report on the 7th meeting of the International Ascites Club

Sepsis is a systemic inflammatory response to the presence of infection, mediated via the production of many cytokines, including tumour necrosis factor (TNF-), interleukin (IL)-6, and IL-1, which cause changes in the circulation and in the coagulation cascade. There is stagnation of blood flow and poor oxygenation, subclinical coagulopathy with elevated D-dimers, and increased production of superoxide from nitric oxide synthase. All of these changes favour endothelial apoptosis and necrosis as well as increased oxidant stress. Reduced levels of activated protein C, which is normally anti-inflammatory and antiapoptotic, can lead to further tissue injury. Cirrhotic patients are particularly susceptible to bacterial infections because of increased bacterial translocation, possibly related to liver dysfunction and reduced reticuloendothelial function. Sepsis ensues when there is overactivation of pathways involved in the development of the sepsis syndrome, associated with complications such as renal failure, encephalopathy, gastrointestinal bleed, and shock with decreased survival. Thus the treating physician needs to be vigilant in diagnosing and treating bacterial infections in cirrhosis early, in order to prevent the development and downward spiral of the sepsis syndrome. Recent advances in management strategies of infections in cirrhosis have helped to improve the prognosis of these patients. These include the use of prophylactic antibiotics in patients with gastrointestinal bleed to prevent infection and the use of albumin in patients with spontaneous bacterial peritonitis to reduce the incidence of renal impairment. The use of antibiotics has to be judicious, as their indiscriminate use can lead to antibiotic resistance with potentially disastrous consequences.

Transjugular intrahepatic portosystemic shunt in refractory ascites: a meta-analysis

Transjugular intrahepatic portosystemic shunt (TIPS) is a more effective treatment for refractory ascites than large volume paracentesis (LVP), but the magnitude of its effect in terms of control of ascites, encephalopathy and survival has not been established.

AIM

This meta-analysis compare TIPS to LVP in terms of control of ascites at 4 and 12 months, encephalopathy and survival at 1 and 2 years.

RESULTS

Five randomized controlled trials involving 330 patients were included. In the TIPS group, control of ascites was more frequently achieved at 4 months (66% vs 23.8%, mean difference: 41.4%, 95% confidence interval (CI): 29.5-53.2%, P < 0.001) and 12 months (54.8% vs 18.9%, mean difference: 35%, 95% CI: 24.9-45.1%, P < 0.001), whereas encephalopathy was higher (54.9% vs 38.1%, mean difference: 17%, 95% CI: 7.3-26.6%, P < 0.001). Survival at 1 year (61.7% vs 56.5%, mean difference: 3.2%, 95% CI: -14.7 to 21.9%) and 2 years (50% vs 42.8%, mean difference: 6.8%, 95% CI: -10 to 23.6%) were not significantly different.

CONCLUSIONS

TIPS is a more effective treatment for refractory ascites than LVP. However, TIPS increase encephalopathy and does not improve survival.

Tezosentan, an endothelin receptor antagonist, limits liver injury in endotoxin challenged cirrhotic rats

BACKGROUND/AIMS

Lipopolysaccharide (LPS) induces liver injury which is associated with upregulated endothelin (ET)-1 production. The aim of this study was to investigate the effects of tezosentan, a non-selective ETA and ETB receptor antagonist, in LPS challenged rats with cirrhosis.

METHODS

Rats with cirrhosis received LPS and then tezosentan or placebo one hour later. Four hours after LPS administration, rats were killed to measure serum transaminase activity and plasma tumour necrosis factor alpha (TNF-alpha) levels. Hepatic inducible nitric oxide synthase (iNOS), myeloperoxidase (MPO), a marker of neutrophil infiltration, and cyclooxygenase (COX)-2 expression were also measured.

RESULTS

LPS administration significantly decreased arterial pressure and significantly increased plasma endothelin levels. Following LPS and tezosentan administration, serum aspartate aminotransferase and alanine aminotransferase activities were similar to those in the control group while they were increased by more than 700% with LPS alone. Plasma TNF-alpha levels were significantly lower in rats receiving LPS and tezosentan (182 (38) pg/ml) compared with those receiving LPS alone (821 (212) pg/ml). Tezosentan significantly decreased hepatic MPO activity and hepatic neutrophils but had no effect on LPS induced iNOS or COX-2. Survival rate was significantly higher in rats receiving LPS plus tezosentan (80%) than in rats receiving LPS alone (50%).

CONCLUSION

In LPS challenged cirrhotic rats, tezosentan administration prevents LPS induced liver injury by decreasing intrahepatic neutrophil infiltration. In addition, tezosentan increases survival in these rats.

Rubber Tree (Hevea brasiliensis) Bark Necrosis Syndrome II: First Comprehensive Report on Causal Stresses

Bark necrosis (BN), described and first studied in Côte d'Ivoire in the 1980s (2), affects most modern rubber plantations (i.e., grafted trees with high-yielding clones, intensive exploitation due to tapping frequency, and use of Ethrel as a yield stimulant) worldwide with a wide range of severity across sites. While previous (3) and recent (4) etiological analyses remain inconclusive, environmental factors were shown associated with BN. Numerous epidemiological surveys conducted in various African and Asian plantations on recently tapped blocks (less than 10-year-old trees) revealed the nonrandom location of the earliest single diseased trees. These risky areas are mainly characterized by the proximity of a swamp, plantation road, windrow, old bulldozer track, residual forest stump, or slope break. In BN emergence areas, while no significant correlation was found with chemical soil parameters, physical soil analyses (e.g., penetrometer) revealed higher soil compaction often associated with poorer rhizogenesis in BN trees (comparative root counts made in pits close to healthy or BN trees). Furthermore, initial BN symptoms were preferentially observed near the grafted bud at the rootstock/scion junction (RS/S). Numerous comparative ecophysiological measurements of leaf water potential, stem water potential, and predawn base potential using a plant moisture stress (PMS) pressure chamber indicated water stress in BN trees. These results and preliminary dye transfer studies at the RS/S junction suggested a nonoptimal vascular relation between the root system and the trunk of BN trees. In conclusion, compaction-associated reduced water availability of the soil and poor root capacity to meet the water demand during drier dry seasons combined with disturbed sap flows and recurrent local water drainage (latex flows) are now suspected to jointly act as the main exogenous causal stresses that induce the BN process at the RS/S bud zone before spreading upward to the tapping cut. This multidisciplinary approach gives a new comprehensive scenario for the emergence of this multifactorial physiological disease, now suspected to involve cyanide release (1) into the inner phloem of the rubber tree. References: (1) H. Chrestin. Plant Dis. 88:1047, 2004. (2) D. Nandris et al. Eur. J. For. Pathol. 21:325, 1991. (3) D. Nandris et al. Eur. J. For Pathol. 21:340, 1991. (4) F. Pellegrin et al. Plant Dis. 88:1046, 2004.

Review article: hepatorenal syndrome--definitions and diagnosis

Hepatorenal syndrome (HRS) is a severe complication of cirrhosis that develops in the final phase of the disease. Two types of HRS exist. Type 1 is defined by a rapid reduction of renal function and in type 2 HRS the reduction of renal function is slowly progressive. Type 1 HRS is diagnosed when the serum creatinine level increases by more than 50% of the baseline value to above 133 micromol/L. According to the International Ascites Club, HRS is defined by the presence of five criteria: (1) severe cirrhosis; (2) glomerular hypofiltration; (3) no other functional or organic causes; (4) failure of plasma volume expansion; (5) no proteinuria. Additional diagnostic criteria may be present. The diagnosis of HRS may be difficult in patients with severe cirrhosis. Other types of acute renal failure may occur. For example, ischaemic or toxic tubular necrosis or sepsis may cause renal failure in these patients. Furthermore, uncontrolled HRS may lead to ischaemic tubular necrosis; thus, these patients must be managed as soon as possible in an intensive care unit.

Nosocomial and community-acquired spontaneous bacterial peritonitis: comparative microbiology and therapeutic implications

In order to compare the microbiological characteristics of nosocomial and community-acquired episodes of bacterial peritonitis, 95 consecutive, spontaneous episodes were reviewed. Seventy of these episodes were bacteriologically documented. Fifty-three (55.8%) episodes were nosocomial and 42 (44.2%) were community acquired. A total of 78 pathogens were isolated, including 40 gram-positive cocci (34 streptococci, 6 Staphylococcus aureus), 35 gram-negative bacilli (including 23 Escherichia coli), 2 gram-positive bacilli and 1 yeast. Streptococci were found more frequently in community-acquired episodes (53.8%) than in nosocomial episodes (33.3%). Gram-negative bacilli were significantly more frequent in nosocomial episodes than in community-acquired episodes (56.4% vs. 33.3%, P<0.05). Nosocomial isolates were significantly more resistant to amoxicillin-clavulanic acid (48.7% vs. 18.4%, P<0.01) and cefotaxime (33.3% vs. 13.2%, P<0.05) than community-acquired isolates, but no difference was detected regarding resistance to ciprofloxacin. The results indicate that the empirical treatment of spontaneous bacterial peritonitis should differ for nosocomial and community-acquired cases.

Comparison of the effect of terlipressin and albumin on arterial blood volume in patients with cirrhosis and tense ascites treated by paracentesis: a randomised pilot study

BACKGROUND

Patients with cirrhosis and tense ascites treated by paracentesis alone have a decrease in effective arterial blood volume after ascites removal. Although intravenous albumin is effective in preventing paracentesis induced decreased arterial blood volume, its clinical use is controversial. As paracentesis induces arteriolar vasodilation which plays a role in the development of decreased effective arterial blood volume, administration of a vasoconstrictor (terlipressin) could prevent circulatory alterations due to paracentesis.

AIMS

To perform a pilot study comparing the effects of terlipressin and albumin on effective arterial blood volume in patients with cirrhosis treated by paracentesis for tense ascites.

METHODS

Twenty patients with cirrhosis and tense ascites were randomly assigned to be treated by either paracentesis and terlipressin or paracentesis and albumin. Terlipressin (3 mg) or albumin (8 g/l of removed ascites) were administered on the day of paracentesis. Effective arterial blood volume was assessed by measuring plasma renin concentrations at baseline and on the day of hospital discharge (4-6 days after treatment). Decreased effective arterial blood volume was defined as an increase in plasma renin concentrations on the day of hospital discharge of more than 50% of baseline values.

RESULTS

Irrespective of the treatment group, mean values for plasma renin concentrations at hospital discharge did not differ from their respective baseline values (p=0.10). Baseline plasma levels of renin concentrations did not differ between the terlipressin and albumin groups (p=0.61). Changes from baseline in plasma renin concentrations did not differ between groups (p=0.39). Three patients in the terlipressin group and three in the albumin group developed decreased arterial blood volume.

CONCLUSIONS

This randomised pilot study suggests that terlipressin may be as effective as intravenous albumin in preventing a decrease in effective arterial blood volume in patients with cirrhosis treated by paracentesis for tense ascites.

Role of small-conductance Ca2+-dependent K+ channels in in vitro nitric oxide-mediated aortic hyporeactivity to alpha-adrenergic vasoconstriction in rats with cirrhosis

BACKGROUND/AIMS

In vitro studies have shown that cirrhotic aortas are hyporeactive to the contractile effect of vasoconstrictors because upregulated endothelial nitric oxide-synthase (NOS) overproduces nitric oxide (NO). Although stimulation of endothelial small-conductance Ca2+-dependent K+ (SK(Ca)) channels may elicit vasorelaxation in normal arteries, the role of these channels in cirrhosis-induced hyporeactivity is unknown. Thus, the aim of the present study was to investigate the role of endothelial SK(Ca) channels in cirrhosis-induced, NO-mediated, in vitro aortic hyporeactivity to alpha1-adrenergic vasoconstrictors.

METHODS

Isolated thoracic aortas from cirrhotic and normal rats were used. The effects of apamin, a selective SK(Ca) channel blocker, were measured on the vascular reactivity to phenylephrine. In addition, SK(Ca) channel protein expression was studied. The effects of iberiotoxin and charybdotoxin, blockers of other K(Ca) channels, were also studied in cirrhotic aortas.

RESULTS

Apamin suppressed cirrhosis-induced aortic hyporeactivity to phenylephrine in an endothelium-dependent, NOS-inhibitor-sensitive manner. SK(Ca) channel protein was overexpressed in cirrhotic aortic walls. Iberiotoxin abolished cirrhosis-induced aortic hyporeactivity to phenylephrine in an endothelium-dependent but NOS-inhibitor-resistant manner. Charybdotoxin did not induce any significant increase in phenylephrine-elicited contraction.

CONCLUSIONS

In cirrhotic aortas, the overexpression and overactivity of endothelial SK(Ca) channels contributes to in vitro NO-mediated hyporeactivity to the contractile action of alpha1-adrenergic agonists.

Characteristics of calcium uptake by BeWo cells, a human trophoblast cell line

Placental transfer of maternal calcium (Ca(2+)) is a crucial process for fetal development although the biochemical mechanisms responsible for this transfer are largely unknown. We have investigated the characteristics of Ca(2+)uptake by the human placental trophoblast cell line BeWo. The kinetics studies revealed an active extracellular Ca(2+)uptake by BeWo cells, which was rapid in the first 2 min (initial velocity (V(i)) of 4.17+/-0.25 nmol/mg/min), and showed a subsequent plateau. Uptake experiments performed at V(i)with increasing concentrations of Ca(2+)resulted in a typical saturation curve (K(m)of 0.54+/-0.07 m m and V(max)of 7.07+/-0.28 nmol/mg protein/min). Lowering the pH of the incubation medium from 7.4 to 5.5 led to Ca(2+)uptake inhibition of 40-50 per cent. The presence of voltage-sensitive (l -type) Ca(2+)channels in BeWo cells was demonstrated by Western blot. Therefore, the implication of such channels in basal Ca(2+)uptake of BeWo cells was investigated. Cell depolarization with extracellular high potassium concentration (40 m m), and hyperpolarization with extracellular high chloride concentration (60 m m) or with valinomycin (10 microm) did not influence the basal Ca(2+)uptake of BeWo cells. The L-type Ca(2+)channel modulators (Bay K 8644 and Nitrendipine) had no effect on the Ca(2+)uptake. An antagonist of receptor-mediated, store-operated and voltage-gated Ca(2+)channels (SKF-96365) also did not modulate the Ca(2+)uptake of BeWo cells. Therefore, our results indicate that the basal Ca(2+)uptake of BeWo cells is inhibited by lowering pH of the incubation medium, is voltage independent, and is not influenced by l -type Ca(2+)channel and capacitative Ca(2+)conductance modulators.

Role of nitric oxide in hepatopulmonary syndrome in cirrhotic rats

The hepatopulmonary syndrome (HPS) is characterized by intrapulmonary vascular dilatations and an increased alveolar-arterial oxygen difference (AaPO(2)). Exhaled nitric oxide (NO) concentrations are elevated, suggesting that pulmonary NO overproduction may be the mechanism underlying HPS. We investigated whether common bile duct ligation in rats results in lung NO overproduction and whether normalization of NO synthesis by a 6-wk course of N(G)-nitro-L-arginine methyl ester (L-NAME) (5 mg x kg(-)(1) x d(-)(1)) prevents HPS. Untreated cirrhotic rats showed increases in AaPO(2) and in cerebral uptake of intravenous (99m)Tc-labeled albumin macroaggregates (indicating intrapulmonary vascular dilatations), with decreases in pulmonary vascular resistance and in pulmonary vasoconstriction induced by angiotensin II and hypoxia. Increases were found in exhaled NO; pulmonary total and calcium-dependent NO synthase (NOS) activities; and pulmonary expression of inducible and, to a lesser extent, endothelial NOS. Accumulation of intravascular macrophages accounted for the inducible NOS expression. L-NAME normalized AaPO(2), brain radioactivity, pulmonary vascular resistance, reactivity to hypoxia and angiotensin II, exhaled NO, and NOS activities. These findings suggest that HPS and the associated reduced response to pulmonary vasoconstrictors seen in untreated cirrhotic rats are related to increased pulmonary NO production dependent primarily on increases in the expression and activities of inducible NOS within pulmonary intravascular macrophages.

Pathogenesis of portal hypertension

Portal hypertension is defined by an elevation in portal pressure and is associated with haemodynamic alterations. Haemodynamic changes are characterized by a hyperdynamic circulation in the splanchnic and systemic territories and a reduced pressure effect of vasoconstrictive substances. They were observed in both patients and animals with different types of portal hypertension. In this review, the main results and their mechanisms of the splanchnic and systemic haemodynamic alterations in portal hypertension are discussed.