ViscY nuclear magnetic resonance experiments for in situ chemical reaction monitoring under spin diffusion conditions

Viscosity-enhanced spectroscopY (ViscY) offers a new way to analyze complex mixtures of time-varying composition. This communication reports the use of the viscous binary solvent DMSO-d₆/water to induce NMR spin diffusion for in situ chemical reaction monitoring and real-time characterization of a 3-substituted 4-hydroxycoumarin derivative and its side-product.

Use of Diethanolamine as a Viscous Solvent for Mixture Analysis by Multidimensional Heteronuclear ViscY NMR Experiments

Diethanolamine/DMSO-d₆ as a viscous binary solvent is first reported for the individualization of low-polarity mixture components by multidimensional heteronuclear ViscY NMR experiments under spin diffusion conditions. Solvent viscosity induces the slowing down of molecular tumbling, hence promoting magnetization transfer by dipolar longitudinal cross-relaxation. As a result, all ¹H nuclei resonances within the same molecule may correlate in a 2D nuclear Overhauser effect spectroscopy (NOESY) spectrum, giving access to mixture analysis. We offer a new way to analyze mixtures by considering 3D heteronuclear heteronuclear single-quantum coherence-NOESY (HSQC-NOESY) experiments under viscous conditions. We state the individualization of four low-polarity chemical compounds dissolved in the diethanolamine/DMSO-d₆ solvent blend using homonuclear selective 1D, 2D ¹H-¹H NOESY experiments and heteronuclear 1D, 2D ¹H-¹⁹F heteronuclear Overhauser effect spectroscopy, 2D ¹H-¹⁹F, ¹H-³¹P HSQC-NOESY, and 3D ¹H-¹⁹F-¹H, ¹H-³¹P-¹H HSQC-NOESY experiments by taking profit from spin diffusion.

ViscY NMR experiments in phosphoric acid as a viscous solvent for individualization of small molecules within mixtures by spin diffusion

The analysis of small molecules within complex mixtures is a particularly difficult task when dealing with the study of metabolite mixtures or chemical reaction media. This issue has fostered in recent years an active search for effective and practical solutions. In this context, the ViscY NMR approach has been recently proposed. ViscY collectively designates the NMR experiments that take advantage of spin diffusion in highly viscous solvents or solvent blends for the individualization of the NMR spectra of small molecule mixture components. Two viscous media were prepared from ortho-phosphoric acid (85%) solution by dilution with either D2O or DMSO-d6, thus providing solvent blends with slightly different polarities in which all liquid-state NMR experiments can be carried out easily. Two mixtures, one of four structurally close dipeptides and one of four low-polarity phosphorus-containing compounds, were used for the method assessment, using ViscY experiments such as homonuclear selective 1D and 2D 1H NOESY experiments, heteronuclear 2D 1H-15N/1H-31P HSQC-NOESY and 1H-13C/1H-15N/1H-31P NOAH experiments.

The Three Pillars of Natural Product Dereplication. Alkaloids from the Bulbs of Urceolina peruviana (C. Presl) J.F. Macbr. as a Preliminary Test Case

The role and importance of the identification of natural products are discussed in the perspective of the study of secondary metabolites. The rapid identification of already reported compounds, or structural dereplication, is recognized as a key element in natural product chemistry. The biological taxonomy of metabolite producing organisms, the knowledge of metabolite molecular structures, and the availability of metabolite spectroscopic signatures are considered as the three pillars of structural dereplication. The role and the construction of databases is illustrated by references to the KNApSAcK, UNPD, CSEARCH, and COCONUT databases, and by the importance of calculated taxonomic and spectroscopic data as substitutes for missing or lost original ones. Two NMR-based tools, the PNMRNP database that derives from UNPD, and KnapsackSearch, a database generator that provides taxonomically focused libraries of compounds, are proposed to the community of natural product chemists. The study of the alkaloids from Urceolina peruviana, a plant from the Andes used in traditional medicine for antibacterial and anticancer actions, has given the opportunity to test different approaches to dereplication, favoring the use of publicly available data sources.

Practical implementation of automated closed-loop insulin delivery: A French position statement

Automated closed-loop (CL) insulin therapy has come of age. This major technological advance is expected to significantly improve the quality of care for adults, adolescents and children with type 1 diabetes. To improve access to this innovation for both patients and healthcare professionals (HCPs), and to promote adherence to its requirements in terms of safety, regulations, ethics and practice, the French Diabetes Society (SFD) brought together a French Working Group of experts to discuss the current practical consensus. The result is the present statement describing the indications for CL therapy with emphasis on the idea that treatment expectations must be clearly defined in advance. Specifications for expert care centres in charge of initiating the treatment were also proposed. Great importance was also attached to the crucial place of high-quality training for patients and healthcare professionals. Long-term follow-up should collect not only metabolic and clinical results, but also indicators related to psychosocial and human factors. Overall, this national consensus statement aims to promote the introduction of marketed CL devices into standard clinical practice.

[Sequelae in bell's palsy: Prognostic factors for recovery]

OBJECTIVES

Facial palsy can be assessed using objective and subjective tools. The main purpose of this work was to use these tools to determine at 12 months the percentage of patients with sequelae and to specify the type of sequelae.

MATERIAL AND METHODS

Twenty-three patients with facial palsy were followed in this prospective and longitudinal study. They have been evaluated every 3 months during a year with the House and Brackmann grading scale and the Sunnybrook Facial Grading System. At 12 months, group A was composed of patients with complete recovery and group B, patients with sequelae.

RESULTS

At 3 months, in patients of group B, the House-Brackmann grading scale (P=0.0134), the Sunnybrook Facial Grading System global score (P=0.0283) and dynamic score (P=0.0148) were lower than group A. Moreover, the movement "brow lift" (P=0.0181) seems to be relevant to predict follow-up. Synkinesis on "brow lift" (P=0.0270) and the treatment delay (P=0.0384) increased for group B. Sex, age, paralyzed side and recurrence of facial palsy had no influence.

CONCLUSION

Objective and subjective tools determine thresholds and predictive scores of recovery with sequelae at 1 year. Nevertheless, it is relevant to assess clinically specific facial movements, such as "brow lift", to specify a recovery potential and to predict sequelae a year after the onset of facial palsy. As the treatment delay influences recovery, drug treatment should be recommended as early as possible.

Optimization of a hot-cavity type resonant ionization laser ion source

Resonant Ionization Laser Ion Source (RILIS) is nowadays an important technique in many Radioactive Ion Beam (RIB) facilities for its reliability and ability to ionize efficiently and element selectively. Grand Accélérateur National d'Ions Lourds (GANIL) Ion Source using Electron Laser Excitation (GISELE) is an off-line test bench for RILIS developed to study a fully operational resonant laser ion source at GANIL facility. The ion source body has been designed as a modular system to investigate different experimental approaches by varying the design parameters, to develop the future on-line laser ion source. The aim of this project is to determine the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. Latest results concerning emittance and time profile development as a function of the temperature for different ion source versions will be presented.

Reference centres for adults with rare and complex cancers - Policy recommendations to improve the organisation of care in Belgium

BACKGROUND

Rare and/or complex cancers call for a very specific expertise and adequate infrastructure. In Belgium, every hospital with a programme in oncology can deliver care for adults with rare and/or complex cancer types, without having demonstrated a specific know-how to adequately manage these patients. Therefore, the Minister of Health ordered a scenario for the organisation of care for adults with rare and/or complex cancers, taking into account the current Belgian situation and relevant foreign experience.

METHODS

Combined methods were used in this study: a literature review, the consultation of stakeholders, in depth discussions in 14 multidisciplinary groups leading to concrete proposals for several rare/complex cancers and the consultation of a panel of expert pathologists.

RESULTS

The core recommendation is the set-up of shared care networks around reference centres, with multidisciplinary teams of recognised expertise in specific rare/complex cancers. The definition of minimum caseloads for hospitals and medical specialists, the evaluation of the quality of care, a model of diagnostic confirmation and the set-up of a national portal website which provides information on rare and/or complex cancers and reference centres are highly recommended.

CONCLUSION

It is no longer practicable, efficient or ethical that every hospital or every practitioner continues to offer care for every rare/complex cancer. Improving the quality of rare/complex cancer care requires to concentrate expertise and sophisticated infrastructure in reference centres. Furthermore, the formation of networks between reference centres and peripheral centres will allow a delivery of care combining expertise and proximity. The next step is the translation of the recommendations into policy decisions. It is very well realised that this will take some courage and that a certain degree of resistance will have to be surmounted, but eventually, the best interest of the patient should prevail.

Treating diabetes with islet transplantation: lessons from the past decade in Lille

Type 1 diabetes (T1D) is due to the loss of both beta-cell insulin secretion and glucose sensing, leading to glucose variability and a lack of predictability, a daily issue for patients. Guidelines for the treatment of T1D have become stricter as results from the Diabetes Control and Complications Trial (DCCT) demonstrated the close relationship between microangiopathy and HbA1c levels. In this regard, glucometers, ambulatory continuous glucose monitoring, and subcutaneous and intraperitoneal pumps have been major developments in the management of glucose imbalance. Besides this technological approach, islet transplantation (IT) has emerged as an acceptable safe procedure with results that continue to improve. Research in the last decade of the 20th century focused on the feasibility of islet isolation and transplantation and, since 2000, the success and reproducibility of the Edmonton protocol have been proven, and the mid-term (5-year) benefit-risk ratio evaluated. Currently, a 5-year 50% rate of insulin independence can be expected, with stabilization of microangiopathy and macroangiopathy, but the possible side-effects of immunosuppressants, limited availability of islets and still limited duration of insulin independence restrict the procedure to cases of brittle diabetes in patients who are not overweight or have no associated insulin resistance. However, various prognostic factors have been identified that may extend islet graft survival and reduce the number of islet injections required; these include graft quality, autoimmunity, immunosuppressant regimen and non-specific inflammatory reactions. Finally, alternative injection sites and unlimited sources of islets are likely to make IT a routine procedure in the future.

Progress of resonant ionization laser ion source development at GANIL

SPIRAL2 (Système de Production d'Ions Radioactifs Accélérés en Ligne) is a research facility under construction at GANIL (Grand Accélérateur National d'Ions Lourds) for the production of radioactive ion beams by isotope separation on-line methods and low-energy in-flight techniques. A resonant ionization laser ion source will be one of the main techniques to produce the radioactive ion beams. GISELE (GANIL Ion Source using Electron Laser Excitation) is a test bench developed to study a fully operational laser ion source available for Day 1 operations at SPIRAL2 Phase 2. The aim of this project is to find the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. Latest results about the new ion source geometry will be presented.

Effects of pro-cholinergic treatment in patients suffering from spatial neglect

Spatial neglect is a neurological condition characterized by a breakdown of spatial cognition contralateral to hemispheric damage. Deficits in spatial attention toward the contralesional side are considered to be central to this syndrome. Brain lesions typically involve right fronto-parietal cortices mediating attentional functions and subcortical connections in underlying white matter. Convergent findings from neuroimaging and behavioral studies in both animals and humans suggest that the cholinergic system might also be critically implicated in selective attention by modulating cortical function via widespread projections from the basal forebrain. Here we asked whether deficits in spatial attention associated with neglect could partly result from a cholinergic deafferentation of cortical areas subserving attentional functions, and whether such disturbances could be alleviated by pro-cholinergic therapy. We examined the effect of a single-dose transdermal nicotine treatment on spatial neglect in 10 stroke patients in a double-blind placebo-controlled protocol, using a standardized battery of neglect tests. Nicotine-induced systematic improvement on cancellation tasks and facilitated orienting to single visual targets, but had no significant effect on other tests. These results support a global effect of nicotine on attention and arousal, but no effect on other spatial mechanisms impaired in neglect.

Measuring determinants of oral health behaviour in parents of preschool children

OBJECTIVE

The aim of this study was to develop a valid and reliable measure for oral health behaviour and its determinants in five-year-old Flemish children, based on the Theory of Planned Behaviour (TPB) and to test its predictive validity.

METHODS

1157 parents of five-year-olds completed a questionnaire measuring three behaviours related to oral health among children (dietary habits, oral hygiene, dental attendance) and their determinants (attitude, subjective norms, perceived behavioural control, intention). The sample was randomly split in two halves and principal component analyses were performed on one half sample to identify the factor structure. Confirmatory factor analyses were performed on the remaining half sample to obtain a cross-validation. Predictive validity was tested using multiple regression analyses.

RESULTS

For each behaviour four component structures reflecting the TPB-dimensions, accounting for 44% to 55% of the variance were retrieved and confirmed in the cross-validation. Internal consistency (Cronbach's alpha) of the scales ranged from 0.52 to 0.80. A sizeable percentage of variance of intentions and behaviours was explained by the model.

CONCLUSIONS

The TPB components were significant predictors of intentions and behaviours. These findings argue for the reliability and validity of the questionnaire for exploring determinants underlying parental oral health behaviour.

Oral health and oral health-related behaviour in preschool children: evidence for a social gradient

This study aims to investigate the social gradient in the reported oral health-related behaviour and oral health status of preschool children. Participants were 1,057 children born between October 2003 and July 2004 in Flanders, Belgium. Oral health examinations were performed by trained dentists when the children were 3 and 5 years old (respectively, in 2007 and 2009); data on dietary habits, oral hygiene habits and dental attendance of the children were obtained through structured questionnaires completed by the parents. Maternal educational level, measured in four categories, was used as a proxy of socio-economic status. Logistic and ordinal regressions showed a social gradient for the oral health-related behaviours: a lower educational level of the mother was related to a higher consumption of sugared drinks between meals and to a lower brushing frequency and dental attendance of the child. Children from low-educated mothers also had seven times more chance to present with caries experience than children from mothers with a bachelor degree. Contrary to the expectations, there was a deviation from the gradient in 3-year-olds from the highest educational group showing an increased risk for caries experience (OR = 3.84, 95 % CI = 1.08-13.65). Conclusion. Already in very young children, a graded relationship is observed between socio-economic position, oral health and related behaviours. The results suggest that different approaches are required to promote oral health during early childhood depending on the mother's educational background. As children from the highest social group also have an increased caries risk, specific techniques may be needed.

The oral health status of special olympics athletes in Belgium

OBJECTIVES

To describe and evaluate the oral condition and oral treatment needs of the participants of the Special Olympics Special Smiles program organised in Belgium in 2008.

DESIGN

A cross-sectional study where the data were collected through interviews and clinical examinations.

PARTICIPANTS

687 Belgian Special Smiles athletes participated, mean age 33 years.

RESULTS

More than 70% had at least one missing tooth. Distinct signs of gingivitis and visible caries experience were observed in 44% and 22% of dentate athletes respectively. Dutch-speaking athletes were less likely to present with untreated caries (OR: 0.46; 95% CI: 0.31-0.68) or with gingivitis (OR: 0.51; 95% CI: 0.37-0.71) compared to their French-speaking colleagues. Signs of past injury were identified in 12% of athletes. Of those athletes with an edentulous mandible, only 53% presented with a removable denture; 73% of athletes missing some maxillary anterior teeth and 30% of those missing all anterior teeth had no prosthetic replacement in the maxilla. Nearly two fifths of athletes were referred for treatment: in 12% of athletes dental treatment was considered urgent.

CONCLUSION

The results suggest that there is a tremendous unmet need for dental treatment in the Belgian Special Smiles population, with French-speaking athletes in greatest need. Improvements in data collection should be encouraged for example. more detailed screening methods (e.g. caries screening including enamel lesions, full periodontal examination) and questionnaires (e.g. inclusion of questions related to dietary habits, dental attendance). In this way barriers to optimal oral health (care) in this population could be further explored, attempts made to reduce them and so reduce health inequalities.

Pantechnik new superconducting ion source: PantechniK Indian Superconducting Ion Source

The new ECR ion source PantechniK Indian Superconducting Ion Source (PKISIS) was recently commissioned at Pantechnik. Three superconducting coils generate the axial magnetic field configuration, while the radial magnetic field is done with the multi-layer permanent magnets. Special care was devoted to the design of the hexapolar structure, allowing a maximum magnetic field of 1.32 T at the wall of the 82 mm diameter plasma chamber. The three superconducting coils using low temperature superconducting wires are cooled by a single double stage cryo-cooler (4.2 K). Cryogen-free technology is used, providing reliability and easy maintenance at low cost. The maximum installed RF power (18.0 GHz) is of 2 kW. Metallic beams can be produced with an oven (T(max) = 1400 °C) installed with an angle of 5° with respect to the source axis or a sputtering system, mounted on the axis of the source. The beam extraction system is constituted of three electrodes in accel-decel configuration. The new source of Pantechnik is conceived for reaching optimum performances at 18 GHz RF frequencies. PKISIS magnetic fields are 2.1 T axial B(inj) and 1.32 T radial field in the wall, variable B(min) with an independent coil and a large and opened extraction region. Moreover, PKISIS integrates modern design concepts, like RF direct injection (2 kW availability), dc-bias moving disk, out-of-axis oven and axial sputtering facility for metal beams. Finally, PKISIS is also conceived in order to operate in a high-voltage platform with minor power consumption.

Multigan®: first experimental results

A new design of a multicharged ion source based on the MONO1000 ECRIS has been presented at the last ECR ion source (ECRIS) Workshop 2010. [L. Maunoury et al., in Proceedings of the XIXth International Workshop on ECR Ion Sources, Grenoble, France, 23-26 August 2010] This source has not only two opening at both ends but also a large space in the middle of the source enabling a direct contact with the ECR plasma. The source has been assembled mechanically and put on a test bench at the Pantechnik company. The primary tests have shown that the plasma ignition occurred at low pressure (10(-6) mbar) and low RF power (10 W). The first experimental results (<Q> = 1.30 for Ar and 1.85 for Xe) demonstrated the potential of this ion source in production of multicharged ion beams.

What do patients with diabetes and diabetologists--especially those in private practice--expect from the new technologies for diabetes care in the future?

Thanks to the high volume of patients'consultations delivered, and especially in private practice, diabetologists are able to accurately describe the expectations of diabetic patients with the new and mostly future technologies. In addition, diabetologists are also able to imagine how these technologies will change their medical practices in future.

Oral hygiene and gingival health in Flemish pre-school children

OBJECTIVES

The study aimed to describe oral hygiene habits, oral hygiene status and gingival health in Flemish pre-school children and to explore factors associated with these clinical oral health variables.

METHODS

Cross-sectional data from 1,071 3-year-old and 1,119 5-year-old children from four geographical areas in Flanders (Belgium) were analysed Buccal plaque accumulation and gingival health were assessed on six index teeth. Data on oral hygiene and dietary habits, oral health behaviour and socio-demographic variables were obtained through questionnaires.

RESULTS

34% of 3-year-olds and 25% of 5-year-olds started brushing before the age of one, 17% of 3-year-olds and 23% of 5-year-olds brushed twice a day. Roughly, 30% of 3-year-olds and 37% of 5-year-olds presented with visible plaque accumulation. In both age groups, only 3 to 4% of children presented with signs of gingival inflammation. Multiple logistic regression models revealed that in both age groups children whose mothers had a college or university degree, had a smaller chance of presenting with visible plaque than children whose mothers had a lower educational level. With gingival health as dependent variable, multiple logistic regression analysis confirmed the major association between bacterial plaque accumulation and the presence of gingivitis. In the oldest age group, children's former exposure to passive smoking was also significantly associated with gingivitis.

CONCLUSION

Parents should be motivated to start brushing at an early age and brush thoroughly in order to maintain good oral health in their offspring. Special attention should go to children raised by mothers with a lower educational level.

GISELE: a resonant ionization laser ion source for the production of radioactive ions at GANIL

SPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz (Germany) and TRIUMF, Vancouver (Canada). A description of this project called GISELE (GANIL Ion Source using Electron Laser Excitation) is presented.

Latest developments at GANIL for stable and radioactive ion beam production

In the frame of the SPIRAL II (Système de Production d'Ions Radioactifs Accélérés en Ligne Partie II) project, several developments of stable and radioactive ion production systems have been started up. In parallel, GANIL has the ambition to preserve the existing stable and radioactive beams and also to increase its range by offering new ones. In order to identify the best directions for this development, a new group called GANISOL has been formed. Its preliminary conclusions and the latest developments at GANIL are presented.

Development of a surface ionization source for the SPIRAL 2 project

Development of new radioactive beams, and thus of new target ion sources (TISs) for isotope-separator-on-line production systems are in progress at GANIL for the SPIRAL 2 project. The efficiency and time response measurements of each step in the production process are crucial to predict and maximize the available yields, in particular, for short lived isotopes. This paper presents a method for measuring these quantities that makes use of a stable alkali chopped beam of controlled intensity. This method was applied to surface ionization source test for high efficiency. Results of recent experiments are presented that include ionization efficiency measurements for Cs, Rb, K, Na, and Li with a graphite and rhenium ionizer and dwell time of these alkalis on graphite. The results enabled to design a first surface ionization source prototype which will be installed in the SPIRAL 2 TIS.

Parental smoking behavior and caries experience in preschool children

OBJECTIVES

The study aimed to explore the association between parental smoking behavior and caries experience in young children, taking into account the socioeconomic status and oral health-related behavior.

METHODS

Cross-sectional data from 1250 3-year-old and 1283 5-year-old children from four geographical areas in Flanders (Belgium) were analyzed. Children were examined at school by trained dentist-examiners, using standard criteria and calibrated examination methodology. Data on oral hygiene and dietary habits, oral health behavior, sociodemographic variables, and parental smoking behavior were obtained through structured questionnaires, completed by the parents.

RESULTS

Visible caries experience (i.e. d(3)mft > 0) was seen in 7% of 3-year olds and 31% of 5-year olds. In both age groups, 30% of the parents reported smoking behavior. Univariable logistic regression analysis with caries prevalence as the dependent variable, revealed that parental smoking was a significant independent variable. After controlling for age, gender, sociodemographic characteristics, oral hygiene, and dietary habits, the effect of family smoking status was no longer significant in 3-year-old children (OR = 1.98; 95% CI: 0.68-5.76). In 5-year olds the significant relationship between parental smoking behavior and caries experience persisted after adjusting for the other evaluated variables (OR = 3.36; 95% CI: 1.49-7.58).

CONCLUSION

The results of this study illustrate the existence of a significant association between parental smoking behavior and caries experience in 5-year-old children.

Measuring oral health behaviour in Flemish health care workers: an application of the theory of planned behaviour

OBJECTIVE

This study describes the development and validation of a questionnaire to measure the determinants of oral health related behaviour in health care workers, based on the Theory of Planned Behaviour (TPB).

RESEARCH DESIGN

A preliminary questionnaire was drafted containing 78 self report items measuring three behaviours related to oral health (i.e. dietary habits, oral hygiene habits and dental attendance), as well as the attitudes, perceived social norms and self-efficacy for each behaviour. The questionnaire was completed by 201 health care workers for the initial validation and 966 other health care workers for a replication.

OUTCOMES

A principal component analysis with Procrustes rotation toward an a priori three component structure on the original sample yielded high congruence measures for reported dental attendance, but not for dietary habits and oral hygiene habits. Subsequent exploratory Varimax rotations and discarding of redundant items resulted in three component solutions explaining 43% of the variance in dietary habits, 57% in oral hygiene habits and 66% in dental attendance, respectively. For all three behaviours, these components corresponded to the dimensions of the TPB. Internal consistency of the scales was satisfactory, with Chronbach's alpha's ranging from 0.51 to 0.87. Scale scores accounted for a significant proportion of the variance in the intention to avoid sweet snacks, to brush teeth, and to attend dental check-ups, and of the frequency of consumption of sweet drinks and frequency of brushing. A confirmatory factor analysis on the larger sample of 966 health care workers provided excellent goodness of fit indices, confirming the construct validity of the scales.

Development of a 1+/N+ setup for the production of multicharged radioactive alkali ions in SPIRAL

In the framework of the production of radioactive ion beams by the isotope separator online method, a new system has been developed at GANIL/SPIRAL I to produce multicharged alkali ions. The principle, referred to as the "direct 1+/N+ method," consists of a surface ionization source associated with a multicharged electron-cyclotron-resonance ion source without an intermediate mass separator. This new system has been tested online using a (48)Ca primary beam at 60.3 A MeV. The experimental evidence of the direct 1+/N+ process has been obtained for a potential difference between the two sources of 11 V and with a 1+/N+ charge breeding efficiency of 0.04% for (47)K(5+). This value is significantly lower than the value of 6% obtained for stable K ions with the standard 1+/N+ method. A possible explanation is given in the text.

The radioactive ion beam production systems for the SPIRAL2 project

The SPIRAL2 project, currently under construction at GANIL, will include an isotope separator on line based facility for the production and acceleration of radioactive ion beams. A superconducting linear accelerator will accelerate 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. These primary beams will be used to bombard both thick and thin targets. We are investigating three different techniques to produce the radioactive ion beams: (1) the neutron induced fission of uranium carbide, (2) the direct interaction of deuterons in a uranium carbide target, and (3) the interaction of a heavy ion beam with a target. All these production systems will be coupled to an ion source. Four kinds of ion sources are foreseen for the ionization of the radioactive atoms: an electron cyclotron resonance ion source, a surface ionization ion source, a forced electron beam induced arc discharge ion source, and a laser ion source depending on the characteristics of the desired radioactive ion beam in terms of intensity, efficiency, purity, etc. A presentation of the SPIRAL2 project and of the different production systems is given.

Status report of stable and radioactive ion beam production at GANIL

GANIL has been producing many stable and radioactive ion beams for nearly 25 years. Constant progresses have been made in terms of intensity, stability, and reliability. The intensity for some stable metallic beams now exceeds or approaches the p microA level at an energy up to 95 MeV/u, e.g., 1.14 p microA for (36)S (65% enriched) at 77 MeV/u, 0.35 p microA for (58)Ni (63% enriched) at 74 MeV/u. Some recent results with Magnesocene using the metallic ions from volatile compounds method should also make possible the production of metallic beams with an intensity greater than 1 p microA. This has still to be measured. The ISOL facility SPIRAL I has been in operation for almost six years. Up to now, 17 exotic He experiments have been done with 14 target/ion-source (TIS) units; 19 other experiments (with O, Ne, Ar, and Kr) have been achieved with 14 TISs. Statistics show a fairly good ratio of available beam time to scheduled beam time. The radioactive beams and available intensities are compiled in this report. Future developments on radioactive ion beam production are briefly presented, while more details will be discussed elsewhere at this conference.

Effect of caries experience in primary molars on cavity formation in the adjacent permanent first molar

This study sought to address the influence of a sound versus affected first and/or second deciduous molar on the incidence of visible caries experience in the adjacent permanent first molar. Clinical and questionnaire data were obtained from a 6-year prospective oral health screening project in Flanders, Belgium (Signal-Tandmobiel project), where 4,468 children (born in 1989) were examined annually during their primary school time. A multiple survival model allowing for dependent data with possible censoring was applied. The impact of timing of tooth emergence (determining the period at risk), gender, presence of sealants and reported oral hygiene habits was also considered. Cavity formation in permanent first molars was clearly influenced by the status of the adjacent primary molars;the effect of the second deciduous molar was most pronounced. Moreover, if both deciduous molars experienced caries and the child presented with poor oral hygiene, a peak in cavity formation of the permanent first molar 1-2 years after emergence was noticed. On the other hand, if a child presented with good oral hygiene, no peak was observed; caries risk increased slightly over time. No significant benefit from restoring primary molars could be demonstrated, possibly because of methodological limitations.

Variables associated with oral hygiene levels in 7-year-olds in Belgium

OBJECTIVES

The present investigation aimed to delineate the extent of the correlation between each of a number of possible associated variables and the amount of plaque (as measured by a plaque index) present in 7-year-old Flemish children and to investigate the potential relation between caries experience and the amount of dental plaque.

PARTICIPANTS

A sample of 4,468 children representative of children living in Flanders and born in 1989 was obtained. Their mean age was 7.1 (SD = 0.4) years with a boys/girls ratio of 51.8%-48.2%.

METHODS

Analyses were performed with ordinal plaque index outcome, considering the children's school (i.e. class) as a random effect. Random effect models were estimated with the SAS procedure Proc NLMIXED.

RESULTS

From the multiple logistic regression analysis, it could be concluded that the older the subjects the more dental plaque was observed (OR = 1.35; CI 1.08-1.68; p = 0.0081). Moreover, four explanatory variables could be identified as significant determinants for dental plaque in the mixed dentition: 'start of brushing after the age of 2' (OR = 1.161; CI: 1.09-1.23; p < 0.0001), 'brushing frequency of < 1x/day' (OR = 1.369; CI: 1.012-1.66; p = 0.0019), 'more than two in between meal snacks' (OR = 1.18; CI: 1.023-1.36; p = 0.0111) and 'daily intake of sugar containing drinks' (OR = 1.24; CI: 1.08-1.42; p = 0.0023). Further, being male was associated with a higher amount of plaque (OR = 1.16; CI: 1.00-1.34; p = 0.0506) and finally, a weak but significant correlation (Spearmans' rho: r = 0.23, p < 0.0001) between caries experience and the amount of cervical plaque was shown.

CONCLUSION

The amount of cervical plaque in the mixed dentition was significantly related to variables associated with oral hygiene and dietary habits. A low but significant correlation between the amount of dental plaque and caries experience was observed.

Modelling tooth emergence data based on multivariate interval-censored data

Studies on emergence of (permanent) teeth are published regularly in the dental literature. Besides descriptive statistics (mean or median values) on emergence times, comparisons between boys and girls are of interest. Gender comparisons are intersubject analyses, but also intrasubject questions, like 'Is there a left-right symmetry with respect to the mean (median) emergence times?' are of interest. Studies on emergence times most often are faced with interval-censored data. We will extend a GEE-type test proposed by Huster et al. for bivariate right-censored data to the multivariate setting with interval-censored data. Central to our paper is to provide appropriate statistical models to resolve some dental questions on emergence. The analyses are based on data from the longitudinal Signal-Tandmobiel study.

[Factors determining dental plaque and their relation to the assessment of caries among 7-year-old Flemish children]

The present investigation aimed to assess the impact of a number of variables on the variation on the amount of dental plaque present in the mixed dentition of 7-year-old Flemish children and to investigate a potential correlation between caries experience and the amount of dental plaque. Analyses were performed with ordinal plaque index as outcome measure, considering the children's school (i.e. class) as a random effect. This random effect turned out to be of great importance when dealing with large clustered samples. From the multiple logistic regression analysis, it was concluded that the older the subjects the more dental plaque was observed (or = 1.35; CI: 1.08-1.68; P = 0.0081). Four exploratory variables, could be identified as important risk indicators for dental plaque accumulation in the mixed dentition: 'start of brushing after the age of 2 years' (or = 1.161; CI: 1.09-1.23; P < 0.0001), 'brushing frequency of < 1 x/day (or = 1.37; CI: 1.12-1.66; P = 0.0019), more than two in between meal snacks (or = 1.18; CI: 1.03-1.36; P = 0.02) and daily intake of sugar containing drinks (or = 1.24; CI: 1.08-1.42; P = 0.002). Further, being male was linked to a higher amount of plaque (or = 1.16; CI: 1.00-1.34; P = 0.0506). Finally a weak but significant correlation (spearman's rho: r = 0.23; P < 0.0001) between caries experience and the amount of cervical plaque was shown.

[In the interests of taking one's time even when one reads a scientific article! Critical review of the literature on tooth eruption]

Nowadays everybody has access to the medical literature, not only through the libraries of the universities, but even more conveniently via Medline and Pubmed. It is very tempting only to read abstracts and summaries instead of "wasting time" by reading the whole article. Reading the article itself however enables the reader to select only these articles that have a good methodological and statistical basis. In this contribution several topics will be discussed that may help the reader to read scientific articles with a critical mind: definitions, quality of the data, study concepts, composition of the sample, control group, statistical analysis, sample size and interpretation of the results. Different items are exemplified with articles that deal with the emergence of permanent teeth.

Short-term clinical study comparing supragingival plaque removal and gingival bleeding reduction of the Philips Jordan HP735 to a manual toothbrush in periodontal patients in a maintenance program

The Philips Jordan HP735 was compared to a manual brush for plaque removal efficacy and reduction of gingival bleeding. Subjects in a periodontal maintenance program were randomly divided into two groups; Group I (n = 27), average age 36.9 years, brushed with the manual brush; and Group II (n = 22), average age 32.9 years, brushed with the Philips Jordan HP735 electric brush. A dichotomous plaque and bleeding index was used at six sites on all teeth at baseline, three, six and nine weeks. The subjects did not use any other cleaning devices during the study. No significant statistical difference in plaque score or bleeding score was found between the two groups at baseline. Plaque scores did not statistically significantly decrease over time in either group, and there was no significant difference in plaque removal between groups during the study. The bleeding index decreased significantly in the electric toothbrushing group; however, due to the large variation in bleeding scores between subjects, the difference in the number of bleeding sites was not statistically significant between the two groups. In conclusion, in a group of periodontal patients in a maintenance phase, using an electric toothbrush did not significantly enhance plaque removal, but did decrease bleeding compared to baseline. The difference in bleeding percentages was not statistically significant compared to a manual brush.

[Diabetes before pregnancy, apropos of 143 cases]

OBJECTIVE

The authors want to appraise the management of diabetes prior to pregnancy in a local population treated in the Lille University Hospital.

METHOD

This is a retrospective study of 143 pregnancies occurring in 111 patients with diabetes prior to pregnancy, between 1987 and 1997, in the Obstetrics Department at the Lille University Hospital.

RESULTS

Only one-third of the patients benefited from preconception management; the stability of diabetes during the first trimester was satisfactory in 50% of the cases. The maternal complications are represented by preeclampsia (20%), metabolic complications specific to diabetes (hypoglycemia, ketoacidosis), the aggravation or the emergence of a retinopathy (10%) and polyhydramnios (19%). Concerning the termination of the pregnancies, of the 147 fetuses (four twin pregnancies), 140 newborns in good health, two neonatal deaths, three in-utero deaths and two therapeutic terminations of pregnancy were observed. The fetal malformation rate was 9.5% (14 cases/147). The cesarean section rate was 63%, whereas the fetal macrosomatia rate was 35%, with dystocia in 26% of the deliveries (outside of planned cesareans). Three shoulder dystocia were observed (two requiring the Jacquemier's maneuver and one with transitory plexus brachial palsy for a newborn weighing 5,650 g).

CONCLUSION

The authors conclude that preconception management (one-third of the patients in this series) and management of during the first trimester of pregnancy (50% in this series) was insufficient. This fact is perhaps due to the confusion, for many practitioners, with gestational diabetes, which is a very mediatized affection, though much less severe for the fetus and mother.

Characterization of mutations in the gene doublecortin in patients with double cortex syndrome

Mutations in the X-linked gene doublecortin, which encodes a protein with no dear structural homologues, are found in pedigrees in which affected females show "double cortex" syndrome (DC; also known as subcortical band heterotopia or laminar heterotopia) and affected males show X-linked lissencephaly. Mutations in doublecortin also cause sporadic DC in females. To determine the incidence of doublecortin mutations in DC, we investigated a cohort of eight pedigrees and 47 sporadic patients with DC for mutations in the doublecortin open reading frame as assessed by single-stranded conformational polymorphism analysis. Mutations were identified in each of the eight DC pedigrees (100%), and in 18 of the 47 sporadic DC patients (38%). Identified mutations were of two types, protein truncation mutations and single amino acid substitution mutations. However, pedigrees with DC displayed almost exclusively single amino acid substitution mutations, suggesting that patients with these mutations may have less of a reproductive disadvantage versus those patients with protein truncation mutations. Single amino acid substitution mutations were tightly clustered in two regions of the open reading frame, suggesting that these two regions are critical for the function of the Doublecortin protein.

The results of computer-assisted ambulatory 16-channel EEG

The objective of this study was to examine the results of 16-channel computer-assisted outpatient long-term EEG monitoring (CO-LTM) and to compare those results to previously published reports using 4- and 8-channel ambulatory cassette-based continuous recordings. Patients were referred to a community-based outpatient EEG service for further diagnostic evaluation using this 16-channel bipolar recording system. 344 patients were recorded for an average of 1.4 days. EEG was reviewed for the presence of patient identified events, computer identified interictal and ictal abnormalities, and periodic time samples. A push-button recording that signified a clinical event was obtained in 166 patients (48.3%); 41 (11.9%) of these recordings included a seizure and 125 (36.3%) showed no EEG changes during the habitual event. An EEG abnormality was identified by the computer in an additional 90 recordings (26.2%), for an overall clinical usefulness of 74.4%. Among the 191 patients referred with previously normal routine EEGs, a total of 129 (67.5%) of these recordings were useful. 48 (25.1%) of these tracings were abnormal and an additional 81 push-button events (42.4%) showing no changes from background EEG were recorded. In conclusion, computer-assisted outpatient EEG monitoring provides good success rates for clinically useful information.

[Postpartum thyroiditis. 31 cases]

Postpartum thyroiditis. 31 cases. Between 1977 and 1986, 29 women consulted in three internal medicine and endocrinology departments for clinical disorders which could be ascribed to 31 episodes of thyroiditis developed within 9 months of giving birth. Thyroiditis was diagnosed clinically on the basis of acute diffuse (11 cases) or nodular (7 cases) goitre formation, signs of dysthyroidism (16 cases) revealed by menstrual disturbances and/or galactorrhoea (11 cases). A thyrotoxic episode was observed in 9 patients; it was either without sequelae (5 cases) of followed by transient hypothyroidism (4 cases). In other patients transient hypothyroidism was observed in 11 cases and permanent hypothyroidism in 5 cases. Six patients showed no sign of dysthyroidism, and the diagnosis was made by immunological, cytological and/or histological examination of the thyroid gland. Circulating anti-thyroid antibodies were present in two-thirds of the patients. The results of radioisotope scanning varied according to the stage of the disease. In these patients, only the absence of goitre was predictive, in 4 out of 5 cases, of subsequent permanent hypothyroidism; in all other patients the prognosis was highly favourable, even without specific treatment.

Current concepts in primary hyperparathyroidism

622 patients were operated on between 1966 and 1988. Urolithiasis was the most common presenting symptom (26%) but routine measurements of serum calcium led to detect 50% cases. At present, the disease is three times more frequent in women than in men. Estrogenic deprivation, neck irradiation (3.4%) and lithium therapy favor the occurrence of hyperparathyroidism (HPT); frequent association with goiter (19.8%), diabetes (8.3%) and multiple endocrine neoplasia (3.5%) has been noticed. Bone Gla protein concentrations correlate with calcium and HPT blood concentrations but do not reflect the severity of bone damage. Dual photon absorptiometry is now available for quantification and follow-up of bone demineralization, especially in asymptomatic forms of HPT.

Long term treatment with the somatostatin analog SMS 201-995 in a patient with a thyrotropin- and growth hormone-secreting pituitary adenoma

A patient with a mixed pituitary tumor secreting TSH and GH was treated, starting 3 months after partial adenomectomy, with the somatostatin analog SMS 201-995 for 8 months. Somatostatin itself inhibited TSH, GH, and alpha-subunit release by the tumor both in vivo and in vitro. Long term treatment with twice daily sc injections of SMS 201-995 resulted in decreased TSH secretion and lower serum thyroid hormone levels. However, euthyroidism was achieved only when the patient was treated with three daily 200-micrograms injections of SMS 201-995. After 30 weeks of SMS 201-995 therapy, TSH secretion increased, while GH secretion remained suppressed. After withdrawal for 6 months, SMS 201-995 (100 micrograms, sc, twice daily) again completely inhibited TSH secretion. SMS 201-995 did not alter the volume of the residual adenomatous tissue. We conclude that SMS 201-995 may be a valuable therapeutic agent for the management of patients with a thyrotroph adenoma. However, desensitization may occur during long term treatment.