Resting energy expenditure in argininosuccinic aciduria and in other urea cycle disorders

No data are available on the specific energy needs of patients affected with Urea Cycle disorders (UCD) and especially argininosuccinic aciduria (ASA). In our experience, ASA patients tend to develop central adiposity and hypertriglyceridemia when treated with apparently adequate energy intake, while the other UCD do not. The aim of this study was to evaluate anthropometric parameters, body composition, risk of metabolic syndrome (MS) and resting energy expenditure (REE), both by indirect calorimetry (IC) and predictive equations, in UCD patients. Hypertension (5/13), pathological waist circumference-to-height ratio (WtHr) (6/13), hypertriglyceridemia (12/13), reduced HDL cholesterol (12/13), and MS (5/13) were found in ASA group. In the ASA cohort, the mean and median IC-REE were 88% of what was predicted by Food and Agriculture Organization of the United Nations and Harris-Benedict equations. The "other UCD" cohort did not show hypertension, dyslipidaemia nor MS; IC-REE was similar to the REE predicted by equations. A significant difference was seen for the presence of hypertension, dyslipidaemia, pathological WtHr, MS and IC-REE/predictive equations-REE in the two cohorts. ASA patients have a risk of overfeeding if their energy requirement is not assessed individually with IC. Excessive energy intake might increase the cardiovascular risk of ASA patients. We suggest to test ASA individuals with IC every year if the patient is sufficiently collaborative. We speculate that most of the features seen in ASA patients might depend on an imbalance of Krebs cycle. Further studies are needed to verify this hypothesis.

P11.24 CR13626, an oral tyrosine kinase inhibitor crossing the blood brain barrier, reduces tumour growth and prolongs survival in a mouse model of glioblastoma

BACKGROUND

Glioblastoma multiforme (GBM) is the most malignant primary brain cancer. Several mutations and alterations of key cellular pathways including tyrosine kinases (TKs) are involved in GBM etiopathogenesis. Currently there is no cure for GBM. Tumour heterogeneity and the presence of the blood brain barrier (BBB), with efflux transporters, are some of the causes of failure of novel therapeutic agents. Thus, appropriate target selectivity and pharmacokinetics (including brain penetration) are critical issues for the generation of potential drug candidates. The main in-vitro and in-vivo properties and antitumour activity of CR13626, a novel brain penetrant TK inhibitor, are presented.

MATERIAL AND METHODS

CR13626 inhibitory activity against a panel of 173 kinases was assessed. The effect on cellular proliferation was verified in different 2D human glioblastoma cell lines (U87MG, U373, U87MG vIII) and in a U87MG 3D spheroid model by ViaCount assays. The in-vivo antitumour activity was determined in a mouse model of glioblastoma based on the orthotopic injection of U87MG-Luciferase GBM cells in nude mice: oral treatment started on day 9 post-implantation and continued for 10 days (50 mg/kg/daily). Tumour progression was evaluated through the measurement of bioluminescence (BLI) at the end of dosing (day 19) and during follow-up (day 26–33). Survival was also monitored. The pharmacokinetics and brain exposure of CR13626 were assessed by LC/MS/MS in plasma and brain homogenate tissues of CD1 and tumour-bearing nude mice.

RESULTS

CR13626 potently inhibited FYN, YES, KDR and EGFR kinases, relevant for GBM development, with IC50 values of 69 nM, 3.6 nM, 82 nM and 6 nM, respectively. The compound reduced the proliferation of different human glioblastoma cell lines (GI50 1–3 µM). In CD1 mice, CR13626 had a good oral bioavailability (72%) and brain penetration (brain/plasma ratio of 1.4). In-vivo BLI analysis indicated a time-dependent reduction of tumour growth, reaching 60% on the last BLI evaluation 33 days post-implantation (i.e. 15 days after the end of dosing). Tumour growth inhibition translated into an increase of 25% of the median survival time of animals treated with CR13626 compared to the vehicle group (p<0.05). The observed antitumour effects agreed with the exposure of tumour-bearing mice to CR13626, which was above the TKs in-vitro IC50 values.

CONCLUSION

The combined abilities of CR13626 to inhibit the activity of TKs involved in GBM development, to cross the BBB, and to reduce tumour growth in-vivo leading to increased survival, warrant its further development as a drug candidate in GBM.

A case of dysgraphia induced by sertraline and a review of official spontaneous adverse reaction databases

WHAT IS KNOWN AND OBJECTIVES

The occurrence of dysgraphia after sertraline intake has never been reported. The objective was to describe a case of this adverse drug reaction and present a review of similar cases held in international databases with a discussion of the possible pharmacological mechanisms.

CASE SUMMARY

We observed a 60-year-old man who experienced resting tremors, dyskinesia and dysgraphia 2 months after a stepwise increase in sertraline dosing from 50 to 200 mg/day.

WHAT IS NEW AND CONCLUSION

Dysgraphia is a possible adverse drug reaction to sertraline, and we suggest that inhibition of extrapyramidal dopaminergic activity might be the pharmacological mechanism.

Targeting of ADAMTS5's ancillary domain with the recombinant mAb CRB0017 ameliorates disease progression in a spontaneous murine model of osteoarthritis

OBJECTIVE

ADAMTS5 (aggrecanase-2) has been demonstrated to be crucial in the development of osteoarthritis (OA), by use of several mouse mutants carrying either truncated, catalytically inactive enzymes or aggrecanase-resistant mutant aggrecan. We have selected recombinant monoclonal antibodies directed against ADAMTS5, by using Intracellular Antibody Capture Technology (IACT). CRB0017 revealed very high affinity for the enzyme in Biacore analyses and very good specificity in a panel of binding assays. Therefore, we tested CRB0017 in a relevant spontaneous OA model, the STR/ort mouse.

DESIGN

STR/ort male mice were recruited at 5 months of age, and treated intra-articularly in each knee with CRB0017 1.2 μg, CRB0017 12 μg, or vehicle. After 6 weeks, the intra-articular administration of CRB0017 was repeated with the same doses. After 3 months from recruitment, the animals were sacrificed and the femorotibial joints processed for histology and scored in a blind fashion according to both Mankin's and the OARSI methods.

RESULTS AND CONCLUSIONS

All histological scores were significantly decreased in the CRB0017 12 μg/knee group compared to vehicle, while administration of CRB0017 1.2 μg was associated with a trend to a decrease in the same parameters. Therefore, CRB0017 administered twice in 3 months could modify the course of OA in the STR/ort mouse, by delaying cartilage breakdown as assessed histologically. The procedure of blind scoring of the histological samples clearly showed that knee intra-articular administration of CRB0017, an anti-ADAMTS5 antibody, dose-dependently improved disease progression in a relevant animal model of OA.

The VEPSY UPDATED Project: clinical rationale and technical approach

More than 10 years ago, Tart (1990) described virtual reality (VR) as a technological model of consciousness offering intriguing possibilities for developing diagnostic, inductive, psychotherapeutic, and training techniques that can extend and supplement current ones. To exploit and understand this potential is the overall goal of the "Telemedicine and Portable Virtual Environment in Clinical Psychology"--VEPSY UPDATED--a European Community-funded research project (IST-2000-25323, www.cybertherapy.info). Particularly, its specific goal is the development of different PC-based virtual reality modules to be used in clinical assessment and treatment of social phobia, panic disorders, male sexual disorders, obesity, and eating disorders. The paper describes the clinical and technical rationale behind the clinical applications developed by the project. Moreover, the paper focuses its analysis on the possible role of VR in clinical psychology and how it can be used for therapeutic change.

The VEPSY UPDATED project: technical and clinical rationale

The emergence of new shared media, such as the Internet and virtual reality are changing the ways in which people relate, communicate, and live. Health care, and in particular clinical psychology, is one of the areas that could be most dramatically reshaped by these new technologies. To exploit and understand this potential is the overall goal of the "Telemedicine and Portable Virtual Environment in Clinical Psychology"--VEPSY UPDATED--an European Community funded research project (IST-2000-25323, http://www.vepsy.com) whose specific goal is the development of different PC based virtual reality modules to be used in clinical assessment and treatment. In particular the developed modules have been using to address the following pathologies: anxiety disorders; male impotence and premature ejaculation; obesity, bulimia and binge-eating disorders. The chapter details the general technical and clinical characteristics of the developed modules.

The VEPSY updated project: virtual reality in clinical psychology

Many of us grew up with the naive assumption that couches are the best used therapeutic tools in psychotherapy. But tools for psychotherapy are evolving in a much more complex environment than a designer's chaise lounge. In particular, virtual reality (VR) devices have the potential for appearing soon in many consulting rooms. The use of VR in medicine is not a novelty. Applications of virtual environments for health care have been developed in the following areas: surgical procedures (remote surgery or telepresence, augmented or enhanced surgery, and planning and simulation of procedures before surgery); preventive medicine and patient education; medical education and training; visualization of massive medical databases; and architectural design for health care facilities. However, there is a growing recognition that VR can play an important role in clinical psychology, too. To exploit and understand this potential is the main goal of the Telemedicine and Portable Virtual Environment in Clinical Psychology--VEPSY Updated--a European Community-funded research project (IST-2000-25323, http://www.vepsy.com). The project will provide innovative tools-telemedicine and portable-for the treatment of patients, clinical trials to verify their viability, and action plans for dissemination of its results to an extended audience-potential users and influential groups. The project will also develop different personal computer (PC)-based virtual reality modules to be used in clinical assessment and treatment. In particular, the developed modules will address the following pathologies: anxiety disorders; male impotence and premature ejaculation; and obesity, bulimia, and binge-eating disorders.

Communication and cooperation in networked environments: an experimental analysis

Interpersonal communication and cooperation do not happen exclusively face to face. In work contexts, as in private life, there are more and more situations of mediated communication and cooperation in which new online tools are used. However, understanding how to use the Internet to support collaborative interaction presents a substantial challenge for the designers and users of this emerging technology. First, collaborative Internet environments are designed to serve a purpose, so must be designed with intended users' tasks and goals explicitly considered. Second, in cooperative activities the key content of communication is the interpretation of the situations in which actors are involved. So, the most effective way of clarifying the meaning of messages is to connect them to a shared context of meaning. However, this is more difficult in the Internet than in other computer-based activities. This paper tries to understand the characteristics of cooperative activities in networked environments--shared 3D virtual worlds--through two different studies. The first used the analysis of conversations to explore the characteristics of the interaction during the cooperative task; the second analyzed whether and how the level of immersion in the networked environments influenced the performance and the interactional process. The results are analyzed to identify the psychosocial roots used to support cooperation in a digital interactive communication.

Characterization of SURF-1 expression and Surf-1p function in normal and disease conditions

Loss-of-function mutations of the SURF-1 gene have been associated with Leigh syndrome with cytochrome c oxidase (COX) deficiency. Mature Surf-1 protein (Surf-1p) is a 30 kDa hydrophobic polypeptide whose function is still unknown. Using antibodies against a recombinant, hemagglutinin-tagged Surf-1p, we have demonstrated that this protein is imported into mitochondria as a larger precursor, which is then processed into the mature product by cleaving off an N-terminal leader polypeptide of approximately 40 amino acids. By using western blot analysis with specific antibodies, we showed that Surf-1p is localized in and tightly bound to the mitochondrial inner membrane. The same analysis revealed that no protein is present in cell lines harboring loss-of-function mutations of SURF-1, regardless of their type and position. Northern blot analysis showed the virtual absence of specific SURF-1 transcripts in different mutant cell lines. This result suggests that several mutations of SURF-1 are associated with severe mRNA instability. To understand better whether and which domains of the protein are essential for function, we generated several constructs with truncated or partially deleted SURF-1 cDNAs. None of these constructs, expressed into Surf-1p null mutant cells, were able to rescue the COX phenotype, suggesting that different regions of the protein are all essential for function. Finally, experiments based on blue native two-dimensional gel electrophoresis indicated that assembly of COX in Surf-1p null mutants is blocked at an early step, most likely before the incorporation of subunit II in the nascent intermediates composed of subunit I alone or subunit I plus subunit IV. However, detection of residual amounts of fully assembled complex suggests a certain degree of redundancy of this system.

The use of PC based VR in clinical medicine: the VREPAR projects

Virtual reality (VR) is an emerging technology that alters the way individuals interact with computers: a 3D computer-generated environment in which a person can move about and interact as if he actually was inside it. Given to the high computational power required to create virtual environments, these are usually developed on expensive high-end workstations. However, the significant advances in PC hardware that have been made over the last three years, are making PC-based VR a possible solution for clinical assessment and therapy. VREPAR - Virtual Reality Environments for Psychoneurophysiological Assessment and Rehabilitation - are two European Community funded projects (Telematics for health - HC 1053/HC 1055 - http://www.psicologia.net) that are trying to develop a modular PC-based virtual reality system for the medical market. The paper describes the rationale of the developed modules and the preliminary results obtained.

Loss-of-function mutations of SURF-1 are specifically associated with Leigh syndrome with cytochrome c oxidase deficiency

Mutations of SURF-1, a gene located on chromosome 9q34, have recently been identified in patients affected by Leigh syndrome (LS), associated with deficiency of cytochrome c oxidase (COX), the terminal component of the mitochondrial respiratory chain. To investigate to what extent SURF-1 is responsible for human disorders because of COX deficiency, we undertook sequence analysis of the SURF-1 gene in 46 unrelated patients. We analyzed 24 COX-defective patients classified as having typical Leigh syndrome (LS(COX)), 6 patients classified as Leigh-like (LL(COX)) cases, and 16 patients classified as non-LS(COX) cases. Frameshift, stop, and splice mutations of SURF-1 were detected in 18 of 24 (75%) of the LS(COX) cases. No mutations were found in the LL(COX) and non-LS(COX) group of patients. Rescue of the COX phenotype was observed in transfected cells from patients harboring SURF-1 mutations, but not in transfected cell lines from 2 patients in whom no mutations were detected by sequence analysis. Loss of function of SURF-1 protein is specifically associated with LS(COX), although a proportion of LS(COX) cases must be the result of abnormalities in genes other than SURF-1. SURF-1 is the first nuclear gene to be consistently mutated in a major category of respiratory chain defects. DNA analysis can now be used to accurately diagnose LS(COX), a common subtype of Leigh syndrome.

Mutations of SURF-1 in Leigh disease associated with cytochrome c oxidase deficiency

Leigh disease associated with cytochrome c oxidase deficiency (LD[COX-]) is one of the most common disorders of the mitochondrial respiratory chain, in infancy and childhood. No mutations in any of the genes encoding the COX-protein subunits have been identified in LD(COX-) patients. Using complementation assays based on the fusion of LD(COX-) cell lines with several rodent/human rho0 hybrids, we demonstrated that the COX phenotype was rescued by the presence of a normal human chromosome 9. Linkage analysis restricted the disease locus to the subtelomeric region of chromosome 9q, within the 7-cM interval between markers D9S1847 and D9S1826. Candidate genes within this region include SURF-1, the yeast homologue (SHY-1) of which encodes a mitochondrial protein necessary for the maintenance of COX activity and respiration. Sequence analysis of SURF-1 revealed mutations in numerous DNA samples from LD(COX-) patients, indicating that this gene is responsible for the major complementation group in this important mitochondrial disorder.

Virtual reality environments for psycho-neuro-physiological assessment and rehabilitation

Virtual Reality Environments for Psychoneurophysiological Assessment and Rehabilitation-is an European Community funded project (Telematics for health-HC 1053 http:/(/)www.etho.be/ht_projects/vrepar/) whose aim is: to develop a PC based virtual reality system (PC-VRS) for the medical market that can be marketed at a price which is accessible to its possible end-users (hospitals, universities and research centres) and which would have the modular, connectability and interoperability characteristics that the existing systems lack; to develop three hardware/software modules for the application of the PC VRS in psychoneurophysiological assessment and rehabilitation. The chosen development areas are eating disorders (bulimia, anorexia and obesity), movement disorders (Parkinson's disease and torsion dystonia) and stroke disorders (unilateral neglect and hemiparesis). This paper presents the rationale of the different approaches and the methodology used.

A study of interactions among markers of macrophage functions in metastatic solid tumors: neopterin levels in relation to those of tumor necrosis factor-alpha and of soluble interleukin-2 receptors

High levels of the macrophage activation marker neopterin have been described in metastatic cancer patients. Since macrophages may either counteract or stimulate tumor development, it is important to establish which macrophage activity is mainly related to neopterin release. The present study was carried out to evaluate neopterin levels in metastatic solid tumor patients in respect with the antitumor macrophage cytokine TNF and with soluble IL-2 receptor (SIL-2R), whose secretion is stimulated by macrophages and it is associated with the immunosuppressive status of cancer patients. The study included 35 patients with metastatic solid neoplasms. Serum levels of neopterin, TNF and SIL-2R were measured in blood samples collected during the morning. Abnormally high concentrations of neopterin were seen in 18/35 (51%) patients. Patients with high levels of neopterin showed significantly higher concentrations of SIL-2R than those with normal neopterin values, whereas no difference was found in TNF levels. This study would suggest that the increased secretion of neopterin may reflect macrophage-mediated immunosuppression in metastatic solid neoplasms, rather than to be associated with the antitumor activity of macrophages.

Uptake of broxaterol by cultured human cells

The mechanism of uptake of the sympathomimetic drug broxaterol by Chang liver and HepG2 cell lines was investigated. When cells were incubated in the presence of low concentrations of broxaterol cell cultures take up (t1/2 = 5-10 min) and, depending on the experimental conditions, accumulate the drug such that the intracellular concentration is over 200-1000 times that in the incubation medium. The uptake was saturable and influenced by the presence of sodium and variations in external pH. These data may represent a model for tissue uptake in vivo in an attempt to investigate that selective uptake of broxaterol is involved in withdrawal of the molecule during drug therapy.

Determination of N-acetylcysteine in human plasma by gas chromatography-mass spectrometry

An automatic mass spectrometric method for the quantitation of N-acetylcysteine (NAC) in human plasma has been developed. NAC was extracted from plasma with ethyl acetate and derivatized in two steps with 2-propanol and pentafluoropropionic anhydride. The volatile derivative obtained was ideal for gas chromatographic-mass spectrometric analysis. Data obtained by analysing the plasma of healthy volunteers to whom 600 mg of NAC had been orally given are reported.

N-pyrene dodecanoyl sulfatide as membrane probe: a study of glycolipid dynamic behavior in model membranes

An N-linked pyrene-dodecanoyl sulfatide was employed to measure the ratio of excimer fluorescence to monomer fluorescence intensities (E/M). The E/M values provided information about both the dynamic behavior and the structural distribution of the labelled glycolipid in note dispersion of micellar sulfatides and multilamellar vesicles of different phospholipids. Most of the labelled sulfatide seems to be located in domains sequestered from the surrounding phospholipids still above the phase transition temperature of the vesicles. The glycolipids sequestered in these domain environments are less sensitive to the structural changes that the addition of cholesterol or Ca2+ can induce in the phospholipid regions during the phase transition.