Influence of DNA condensation state on transfection efficiency in DNA/polymer complexes: an AFM and DLS comparative study.

Atomic force microscopy (AFM) is used to describe the formation process of polymer/DNA complexes. Two main objectives of this research are presented. The first one is to apply AFM as an effective tool to analyse DNA molecules and different polycation/DNA complexes in order to evaluate their degree of condensation (size and shape). The other one is to search for a relationship between the condensation state of DNA and its transfection efficiency. In this study, linear methacrylate based polymers and globular SuperFect polymers are used in order to induce DNA condensation. Ternary complexes, composed of methacrylate based polymers and polyethylene glycol (PEG)-based copolymers, are also investigated. AFM allows us to confirm good condensation conditions and relate them (or not) to transfection efficiencies. These AFM results (obtained after drying in air) are compared with measurements deduced from Dynamic Light Scattering (DLS) experiments performed in water. This comparison allowed us to identify the structural modifications resulting from deposition on the mica surface.

Ectomorphic habitus, severe mental retardation and characteristic face: a new MCA/MR syndrome?

Here we report on 2 mentally retarded sisters with clinical signs and symptoms not seen in a previously delineated MCA/MR syndrome, i.e., normal pre- and perinatal history, severe mental retardation with severe delay in psychomotor development and without development of primary motor abilities and speech, characteristic face with maxillary hypoplasia, large mouth with down-turned corners, short philtrum and everted lower lip, associated with a remarkable ectomorphic habitus.

Cohen syndrome and de novo reciprocal translocation t(5;7)(q33.1;p15.1).

Here we report on a de novo apparently balanced reciprocal 5q;7p translocation in a 15-year-old girl with apparent Cohen syndrome characterized by hypotonia, obesity, multiple congenital anomalies, and mental retardation. This case may indicate that the gene for Cohen syndrome is at 5q33.1 or 7p15.1.

Maternal tobacco exposure and cotinine levels in fetal fluids in the first half of pregnancy.

OBJECTIVE: To evaluate the distribution of cotinine in fetal fluids and serum during the first half of pregnancy, and compare the fetal and maternal cotinine levels in passive and active smokers. METHODS: Maternal smoking status was determined by questionnaire in 85 pregnant women requesting abortion for psychosocial reasons between 7 and 17 weeks' gestation. Coelomic and amniotic fluid samples were collected between 7 and 11 weeks and fetal blood and amniotic fluid between 11 and 17 weeks. Cotinine levels were measured by radioimmunoassay. RESULTS: Women classified themselves as nonsmokers in 40 cases, passive smokers in 19 cases, and voluntary smokers in 26 cases. Five nonsmokers, 16 passive smokers, and all smokers had cotinine levels above the detection limit of the assay. Cotinine was invariably found in coelomic, amniotic, and fetal serum when maternal serum and urine cotinine levels exceeded 25 and 250 ng/mL, respectively. Higher cotinine levels were found in fetal fluids and serum than in maternal serum. Positive linear correlations were found between maternal urine and amniotic fluid cotinine concentrations (r = .75), between maternal urine cotinine concentration and number of cigarettes smoked per day (r = .66), and between maternal and fetal serum cotinine concentrations (r = .97). CONCLUSION: Cotinine accumulates in the fetal compartments as early as 7 weeks' gestation in both active and passive smokers. Women should be advised to give up smoking from conception and avoid environmental tobacco smoke exposure.

Distribution of iron and iron-binding proteins in first-trimester human pregnancies.

OBJECTIVE: To investigate the iron distribution between the maternal and embryonic compartments in the first trimester of pregnancy. METHODS: Coelomic and amniotic fluids (AF) and maternal serum were collected from 36 apparently normal pregnancies at 7-13 weeks of gestation. Iron, transferrin, ferritin, and lactoferrin were measured in all samples. Iron concentrations were also measured in placental villi, liver, gut, and brain samples collected from two embryos. RESULTS: Significantly (median value) lower iron and transferrin levels and higher levels of ferritin were found in the coelomic fluid (iron 4.8 mumol/L; transferrin 0.22 g/L) than in maternal serum (iron 21 mumol/L; transferrin 2.5 g/L). The AF contained significantly lower levels of iron and ferritin (iron less than 1.8 mumol/L; ferritin 2.0 micrograms/L) than both coelomic fluid (iron 4.8 mumol/L; ferritin 287 micrograms/L) and maternal serum (iron 21 mumol/L; ferritin 49 micrograms/L). Transferrin was undetectable (less than 0.08 g/L) in AF samples, and lactoferrin was undetectable (less than 2 micrograms/mL) in both embryonic fluids. The iron concentration in the coelomic fluid increased significantly (P < .001) with advancing gestation (iron at 7-9 weeks 3.8 mumol/L; 9.1-11 weeks 5.9 mumol/L). There was a nonsignificant correlation between coelomic fluid and maternal serum iron and iron-binding protein levels. The highest iron levels were found in the liver (52 mmol/kg dry weight) and brain (49 mmol/kg dry weight) tissues. CONCLUSIONS: The distribution of iron and iron-binding proteins between the maternal and embryo-placental compartments in the first trimester is comparable to that found later in gestation, suggesting that placental iron transfer may occur as early as tertiary villi are formed. The exocoelomic fluid is probably the main iron reservoir in early pregnancy, and the secondary yolk sac is probably the principal route of entry of iron to the embryo.

Measurement of soluble transferrin receptor by immunoturbidimetry and immunonephelometry.

OBJECTIVE: To evaluate and compare two new commercially available immunoturbidimetric and immunonephelometric assays for measuring soluble transferrin receptor (sTfR) in serum. To adapt the immunonephelometric assay to an automated chemistry analyzer. DESIGN AND METHODS: Total imprecisions and detection limits were calculated and compared. Fifty-six samples were used for methods comparison. The nephelometric assay was adapted to the Hitachi 911 analyzer. RESULTS: Both methods displayed acceptable imprecisions and detection limits. Their correlation was good but a proportional bias was observed. The adaptation of the nephelometric assay to the Hitachi 911 was successful. CONCLUSIONS: These two new immunoassays are analytically acceptable and more practicable than previously developed methods. The differences observed between both methods underscores the need for standardization. The nephelometric assay was easily adaptable to an automated chemistry analyzer.

Systemic and intrastriatal theophylline have opposite effects on dopamine and dopamine metabolites measured by intrastriatal microdialysis in the rat.

Using a model of intrastriatal microdialysis, we studied the effect of theophylline, an A1 and A2A adenosine receptor antagonist on striatal dopamine (DA) and DA metabolites. Systemic administration of theophylline (10 and 50 mg/kg) significantly reduced striatal extracellular (EC) levels of DA and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and 4-hydroxy-3-methoxy-phenylacetic acid (HVA). Intrastriatal administration of theophylline (10(-2) M) significantly increased DA and its metabolites (DA1 + 120%; DOPAC, +28%; HVA, +30%). Contradictory effects of systemic and intrastriatal theophylline point to theophylline interactions with different receptors possibly at different locations.

Kinematics of the foot.

Orthogonal stereoradiographs are frequently utilized in determining three-dimensional geometrical parameters of human body segments. They have been applied here in the estimation of the length and elongation of the ligaments of the normal foot. Three small spherical metallic markers were respectively encrusted into the tibia and fibula, the seven bones of the tarsus and into the five metatarsals of an amputated lower limb to identify uniquely their spatial location. The foot was then positioned on a rotating platform. Standardized antero-posterior and lateral radiographs were taken. Afterwards the foot was dissected and the proximal and distal insertions of most of its ligaments were located by means of spherical markers. A second series of orthogonal radiographs were taken of each of the fourteen bones. The radiographs were digitized. The length of each ligament and elongation for a simple and complex movements were calculated by means of a computer program. The results of a simple movement of rotation representing a normal 20 degree dorsiflexion at the talocrural joint and of complex movements of rotation stimulating an abnormal high arch such as encountered in Friedreich's ataxia are presented and discussed.

Pathomechanics and management of scoliosis in Friedreich ataxia patients: preliminary report.

The preliminary results based on a one year study on the evolution and management of scoliosis are presented. Twenty-one patients were followed in the Neuro-Muscular Disease Clinic at Ste-Justine Hospital where standardized spinal radiographs were taken periodically with the Scoliosis Chariot and the Throne. The short period of observation as well as the relatively small number of Friedreich ataxia patients followed requires that these results and the following remarks be interpreted with caution. Pathomechanics -- Between the age groups I (5 - 10 years) and II (10 - 15 years), a substantial increase in the Cobb values occurs. Associated with it, an increase was observed in the thoracic and thoracolumbar projected surface area indices. The relative rotation between the thoracic and lumbar segments was presumed to be the cause of the sudden increase in the Cobb measurements. For the non-ambulatory patients, a decrease in the lumbar lordosis towards a thoraco-lumbar kyphosis as well as a sudden increase in the sacral angle and a drop in the lumbo-sacral angle were associated with the seated posture assumed by the patient. Management -- Prevention of the progression of established curves was our main objective. Careful examination of the spine, depending on the age of the child, in our preliminary study, stimulated early orthopaedic treatment in any curve of 20 degrees or more. There was always concern for curves of 30 degrees or more. In the growing child, bracing was recommended. In the older child, the curve was usually stable after sixteen years of age. Surgery was usually attempted in curves over 40 degrees in the growing child. The same curve was usually stable after the growth period. For the non-ambulatory patients, the present study suggested the prescription of a molded seat with the following characteristics: i) a posterior lumbar support, ii) low thoracic lateral supports and iii) a slight inclination of the seating system. This was presumed to be beneficial in maintaining stability of the spine. Presently, an evaluation of such a device is under investigation.

Roentgenographic study of cavus foot deformity in Friedreich ataxia patients: preliminary report.

The preliminary results based on a three year retrospective study in cavus foot deformity of forty-four Friedreich ataxia patients regularly seen at the Neuromuscular Disease Clinic of Sainte-Justine Hospital have been presented. An accurate "weight-bearing" foot stereoradiographic technique has been recently developed by our group. Since the follow-up period with this device is not sufficient to provide statistical information, the conventional non-weight bearing technique has been utilized in this study to enable a possible comparison between the radiographs of ambulant and non-ambulant patients. Due to the present technique, the results of this study must be interpreted with caution. For 132 pairs of radiographs, 28 parameters have been analyzed. Four of these, namely the calcaneal inclination angle, the first metatarsal inclination angle, the inferior cortex of calcaneus-first metatarsal angle and the first-fifth metatarsals angle, were of particular interest. From these parameters, a preliminary quantitative description of cavus foot deformity in Friedreich's ataxia has been attempted. Three stages of evolution have been tentatively identified for this type of neurological disorder.

Analyzer transfer of a broad range high-sensitivity C-reactive protein immunoassay.

C-reactive protein (CRP) is measured in two main clinical situations: inflammation, where levels in the range of 5-300 mg/L are expected, and, more recently, assessment of the cardiovascular risk, where concentrations between 0.1 and 10 mg/L shoud be determined. Few commercially available methods display a measuring range covering both zones and laboratories are compelled to use two different assay protocols or even two different methods. The aim of the study was to adapt the Roche C-Reactive Protein (Latex) kit, initially developed for the Roche Cobas Integra analyzers, to the Hitachi Modular P800 analyzer in order to obtain on this instrument a broad range assay for CRP measurement. The method was successfully adapted and validated against a high-sensitivity and a traditional assay. The resulting method correlates well with the other two and displays a measuring range of 0.10-171 mg/L with an imprecision lower than 5.5%. This assay could be particularly practical in the routine clinical laboratory, being suitable for every use of CRP measurements.

Whole blood cyclosporin monitoring in liver and heart transplant patients: evaluation of the specificity of a fluorescence polarization immunoassay and an enzyme-multiplied immunoassay technique.

The specificity of two cyclosporin immunoassays were evaluated. Eleven patients were followed for the first four weeks after heart (n = 3) or liver (n = 8) transplantation. Cyclosporin A (CsA) monitoring was performed concomitantly by a monoclonal fluorescence polarization immunoassay (mFPIA) and enzyme-multiplied immunoassay technique (EMIT) during this period. For several patients, cyclosporin monitoring was also performed by high performance liquid chromatography (HPLC) or by polyclonal fluorescence polarization immunoassay (pFPIA). Liver function was assessed by follow-up of plasma total bilirubin, gamma-glutamyl transferase and alkaline phosphatase and renal function by plasma creatinine. All the patients presented episodes of impaired liver function. Higher CsA levels were found using mFPIA measurements as compared to the EMIT measurements (ratio mFPIA:EMIT (medium range) = 1.4 (1.0-2.3)). A higher degree of cross-reactivity of the antibody used in the mFPIA as compared to the EMIT was demonstrated by specific measurements of CsA and its primary metabolite, AM1, by HPLC.

Modelling of a composite prosthesis for quasi-cylindrical ligaments.

A prosthesis for a cruciate ligament of the knee involves the problem of implanting a short and small spring for which the load-deformation response cannot be duplicated by any single man-made material. This work presents a model of the elastic behavior of a two material composite prosthesis made of high-strength fibers spirally wound around a soft elastic core. At each end of the core, the fibers are attached to a pulling device. Under a tension load, the fibers exert a pressure on the core which deforms radially, permitting the elongation of the prosthesis. This allows the achievement of large deformation while both the fibers and the core remain in the elastic domain. The high strength of the spring is provided by the high yield strength of the fibers. The results show the influence of the design variables on the deformation of the prosthesis.

Macrocephaly and mental retardation. The unique association with short stature, spastic paraplegia and CNS malformations.

During a systematic clinical genetic survey of the institutionalized moderately to severely mentally retarded we had the occasion to examine two nonrelated adult patients who presented a similar MCA/MR syndrome: 1) macrocephaly (OFC > 60 cm) with high and broad forehead and contrasting relative midfacial hypoplasia; 2) short stature with small and broad hands and feet; 3) neurological symptoms of a variable degree of spastic paraplegia and severe CNS malformations on CT-scan i.e. internal hydrocephalus and Dandy-Walker variant malformation.

Fryns syndrome: another example of non-lethal outcome with severe mental handicap.

In this report we present clinical data of a patient with Fryns syndrome who survived the neonatal period. Two sibs died intra-uterine. The syndrome is characterized by craniofacial dysmorphism, diaphragmatic hernia and distal limb hypoplasia. Lethality in most cases is caused by the diaphragmatic hernia with concomitant lung hypoplasia. In patients with Fryns syndrome presenting without the diaphragmatic defect and lung-hypoplasia, survival beyond the neonatal period is possible; mental retardation is present in all four patients described so far. This report illustrates, once more, the great intrafamilial variation of the syndrome and emphasises its important consequences for genetic counseling and prenatal diagnosis.

Angelman syndrome in three adult patients with atypical presentation and severe neurological complications.

Angelman syndrome (AS) is a distinct neurogenetic disorder and the phenotype is well known in childhood and adolescence. However, with advancing age the clinical and behavioral phenotype changes. In adulthood, the phenotype can be rather aspecific. We report on AS in 3 severely to profoundly mentally retarded patients, who developed severe neurologic complications of severe tremor, spasticity and coordination problems, resulting into severe loss of function. They presented atypical craniofacial features, short stature, epileptic seizures, microcephaly, brachytelephalangy and absent speech. Two patients presented at an older age a change in day-night rhythm. Based on this experience, we conclude that all severely to profoundly mentally retarded patients with atypical phenotype, spasticity, absent speech, epileptic seizures and changed day-night rhythm are candidates for further cytogenetic and molecular investigation for AS. Clinical photographs of the patient at a younger age can be helpful. The presence of the typical EEG pattern with frontal triphasic delta waves may direct to the diagnosis of AS.

[The medical chemistry department]. / Le Service de Chimie Médicale.

The laboratory of clinical chemistry performs more than 300 different tests in biochemistry, hormone and tumor markers analysis, therapeutic drug monitoring and toxicology. For the most basic tests it has followed the trend of clinical chemistry towards automation and since 2001 the heart of the laboratory is a modular automated system (MODULAR) including a preanalytical platform, unique in Belgium. For more sophisticated tests, the most recent techniques have been implemented, in particular capillary electrophoresis and ICP-MS ("inductively coupled plasma-mass spectrometry). Since 1994, the laboratory has become a reference center in the field of erythrocyte hereditary diseases, combining screening, diagnosis and research. The other research themes are the physiopathology of first trimester pregnancy and the P2Y receptors of extracellular nucleotides.

Neuropsychopathology in 7 Patients with the 22q13 Deletion Syndrome: Presence of Bipolar Disorder and Progressive Loss of Skills.

The 22q13 deletion syndrome is characterised by intellectual disability (ID), delayed or absent speech, autistic-like behaviour and minor, nonspecific dysmorphic features. The deletion of the SHANK3 gene is thought to be responsible for these features. In this study, the clinical data of 7 patients with the 22q13 deletion syndrome are presented, obtained by clinical genetic examination, direct behavioural observation and by interview of family members and/or caregivers, complemented by behavioural questionnaires. The specific focus was on behaviour, psychopathology and the level of functioning during life course in order to determine common features that might contribute to the delineation of the syndrome. Major findings were a high incidence of psychiatric disorders, more in particular bipolar disorder (BPD) and attention deficit hyperactivity disorder (ADHD), and a sudden deterioration after acute events, in addition to a progressive loss of skills over years. Therefore, a deletion of SHANK3 may result in a dysfunctional nervous system, more susceptible to developmental problems and psychiatric disorders on the one hand, less able to recuperate after psychiatric and somatic events, and more vulnerable to degeneration at long term on the other hand. These results are exploratory and need to be confirmed in a larger sample.