Use of illicit substances in a psychosis incidence cohort: a comparison among different ethnic groups in the Netherlands

OBJECTIVE

Use of illicit substances has been suggested as an explanation for the increased incidence of psychosis among some immigrant groups. The aim of the present study is to compare the rates of illicit substance use among immigrants with a first psychosis with that among non-migrants.

METHOD

A population-based, first-contact incidence study in the Netherlands. Patients and key informants were interviewed about drug use in the preceding year.

RESULT

One hundred and eighty-one subjects were examined. Proportions of patients who misused any illicit substance were 23% for Dutch, 17% for Moroccans, 27% for Surinamese, 30% for Turkish subjects, and 33% for other immigrants. Logistic regression analysis, controlling for age and sex, showed that ethnicity did not significantly contribute to the prediction of substance misuse.

CONCLUSION

A higher rate of drug misuse is an unlikely explanation for the increased incidence of psychotic disorders among Moroccan and Surinamese immigrants to the Netherlands.

FIP: a highly automated beamline for multiwavelength anomalous diffraction experiments

FIP is a French Collaborating Research Group (CRG) beamline at the European Synchrotron Radiation Facility (ESRF) dedicated exclusively to crystallography of biological macromolecules, with a special emphasis on multiwavelength anomalous diffraction data collection in the 0.7-1.81 A wavelength range. The optics, consisting of long cylindrical grazing-angle mirrors associated with a cryocooled double-crystal monochromator, delivers an optimal beam in the corresponding energy range. The high level of automation, which includes automated crystal centring, automated data-collection management and data processing, makes the use of this beamline very easy. This is illustrated by the large number of challenging structures that have been solved since 1999.

High-pressure protein crystallography (HPPX): instrumentation, methodology and results on lysozyme crystals

A new set-up and associated methodology for the collection of angle-dispersive diffraction data from protein crystals submitted to high hydrostastic pressure have been developed on beamline ID30 at the ESRF. The instrument makes use of intense X-rays of ultra-short wavelength emitted by two collinear undulators, and combines a membrane-driven diamond-anvil cell mounted on a two-axis goniometer and an imaging-plate scanner. Sharp and clean diffraction pictures from tetragonal crystals of hen egg-white lysozyme (tHEWL) and orthorhombic crystals of bovine erythrocyte Cu, Zn superoxide dismutase (SOD) were recorded at room temperature and pressures up to 0.915 and 1.00 GPa, respectively. The compressibility of tHEWL was determined from unit-cell parameters determined at 24 different pressures up to 0.915 GPa. High-pressure diffraction data sets from several crystals of tHEWL were collected and analyzed. Merging of data recorded on different crystals at 0.30 and 0.58 GPa produced two sets of structure amplitudes with good resolution, completeness, redundancy and R(sym) values. A third set at 0.69 GPa was of a similar quality except a lower completeness. The three structures have been refined. The pressure-induced loss of crystalline order in a tHEWL crystal beyond 0.82 GPa was captured through a series of diffraction pictures.

CYP94A5, a new cytochrome P450 from Nicotiana tabacum is able to catalyze the oxidation of fatty acids to the omega-alcohol and to the corresponding diacid

A full length cDNA encoding a new cytochrome P450-dependent fatty acid hydroxylase (CYP94A5) was isolated from a tobacco cDNA library. CYP94A5 was expressed in S. cerevisiae strain WAT11 containing a P450 reductase from Arabidopsis thaliana necessary for catalytic activity of cytochrome P450 enzymes. When incubated for 10 min in presence of NADPH with microsomes of recombinant yeast, 9,10-epoxystearic acid was converted into one major metabolite identified by GC/MS as 18-hydroxy-9,10-epoxystearic acid. The kinetic parameters of the reaction were Km,app = 0.9 +/- 0.2 microM and Vmax,app = 27 +/- 1 nmol x min(-1) x nmol(-1) P450. Increasing the incubation time to 1 h led to the formation of a compound identified by GC/MS as 9,10-epoxy-octadecan-1,18-dioic acid. The diacid was also produced in microsomal incubations of 18-hydroxy-9,10-epoxystearic acid. Metabolites were not produced in incubations with microsomes of yeast transformed with a control plasmid lacking CYP94A5 and their production was inhibited by antibodies raised against the P450 reductase, demonstrating the involvement of CYP94A5 in the reactions. The present study describes a cytochrome P450 able to catalyze the complete set of reactions oxidizing a terminal methyl group to the corresponding carboxyl. This new fatty acid hydroxylase is enantioselective: after incubation of a synthetic racemic mixture of 9,10-epoxystearic acid, the chirality of the residual epoxide was 40/60 in favor of 9R,10S enantiomer. CYP94A5 also catalyzed the omega-hydroxylation of saturated and unsaturated fatty acids with aliphatic chain ranging from C12 to C18.

The Interdisciplinary Generalist Curriculum (IGC) project: an overview of its experience and outcomes

The Interdisciplinary Generalist Curriculum (IGC) Project was a competitive, seven-year demonstration project funded by the Health Resources and Services Administration (HRSA). It was established to determine whether specific interdisciplinary innovations in preclinical medical school curricula could affect students' selection of careers in family medicine, general internal medicine, or general pediatrics. Through collaboration among the three generalist disciplines, the IGC innovation exposed all preclinical students in ten demonstration schools to a new or significantly enhanced preclinical curriculum that included a direct supervised clinical experience with a generalist physician preceptor. The project was managed by an interdisciplinary executive committee that was codirected by one representative each from family medicine, general internal medicine, and general pediatrics. A national advisory committee with representation from the academic and professional organizations of family medicine, internal medicine, pediatrics, and osteopathy provided input to the executive committee in guiding the project. The project was externally evaluated. Major outcomes of the IGC Project include sustained curricular changes in ten institutions, prompted by relatively few dollars and demonstration of models for collaboration at institutional and national levels. This supplement describes the IGC Project's experience and outcomes so that others may draw pertinent information to apply to their own efforts in medical education.

Incidence of psychotic disorders in immigrant groups to The Netherlands

BACKGROUND

Previous reports on the incidence of schizophrenia in immigrant groups to The Netherlands were based on hospital data.

AIMS

To compare the incidence of psychotic disorders in the immigrant groups to that in natives.

METHOD

Two-year first-contact incidence study in The Hague.

RESULTS

The risks of schizophrenia, schizophreniform or schizoaffective disorder (DSM-IV criteria) were increased for subjects born in Morocco (gender and age-adjusted relative risk=4.5; 95% Cl 1.4-8.5), Surinam (relative risk=3.2; 1.8-5.7), The Netherlands Antilles (relative risk=2.9; 0.9-9.5) and other non-Western countries (relative risk=2.4; 1.3-4.7). This risk was also increased for Moroccans (relative risk=8.0; 2.6-24.5) and Surinamese (relative risk=5.5; 2.5-11.9) of the second generation. The risks for Turkish immigrants, first or second generation, and for immigrants from Western countries were not significantly increased.

CONCLUSIONS

This study indicates that the incidence of schizophrenia is increased in several, but not all, immigrant groups to The Netherlands. It is possible that factors associated with a process of rapid westernisation precipitate schizophrenia in people who are genetically at risk.

Handedness, language lateralisation and anatomical asymmetry in schizophrenia: meta-analysis

BACKGROUND

Cerebral lateralisation appears to be decreased in schizophrenia. Results of studies investigating this, however, are equivocal.

AIMS

To review quantitatively the literature on decreased lateralisation in schizophrenia.

METHOD

Meta-analyses were conducted on 19 studies on handedness, 10 dichotic listening studies and 39 studies investigating anatomical asymmetry in schizophrenia.

RESULTS

The prevalence of mixed- and left-handedness ('non-right-handedness') was significantly higher in patients with schizophrenia as compared to healthy controls, and also as compared to psychiatric controls. The analysis of dichotic listening studies revealed no significant difference in lateralisation in schizophrenia. However, when analysis was restricted to studies using consonant-vowel or fused word tasks, significantly decreased lateralisation in schizophrenia emerged. Asymmetry of the planum temporale and the Sylvian fissure was significantly decreased in schizophrenia, while asymmetry of the temporal horn of the lateral ventricle was not.

CONCLUSION

Strong evidence is provided for decreased cerebral lateralisation in schizophrenia.

From the primary care organizations consortium's proposal to the Interdisciplinary Generalist Curriculum Project

The Interdisciplinary Generalist Curriculum (IGC) Project was one element of an overall federal government strategy designed to promote primary care education. This project, undertaken by the Division of Medicine and Dentistry (DMD), Bureau of Health Professions, Health Resources and Services Administration, U.S. Department of Health and Human Services, was the first large-scale medical education contract initiated by DMD. The IGC Project was based on a model proposed by the Primary Care Organizations Consortium (PCOC). The PCOC thesis was that "if students are to decide to pursue a generalist career they must have the opportunity to be taught by generalists." The PCOC Program required an explicit curriculum focusing on generalist knowledge and skills with an emphasis on technology, in the context of education that required training in ambulatory office-based settings. The PCOC Program specified that responsibility for the program's planning, implementation, and evaluation be shared by the three generalist physician faculties of family medicine, general internal medicine, and general pediatrics. In implementation of this demonstration project in ten medical schools across the nation, several lessons have been learned relative to enhancement of generalist education. Among these lessons is that seed money targeted to initiate modest change can act as a catalyst and improve the knowledge and skills afforded medical students concerning generalist practice. Limited funds provided over a sufficient period of time can induce schools to undertake significant curricular change.

A national survey of training in substance use disorders in residency programs

OBJECTIVE

To determine the amount of formal training in substance use disorders that occurs in selected residency programs and to identify the perceived barriers to such training.

METHOD

A national survey was conducted of program directors in emergency medicine, family medicine, internal medicine, obstetrics/gynecology, osteopathic medicine, pediatrics and psychiatry. In 1997, program directors were mailed a brief survey to determine the extent to which required training in substance use disorders occurred and the median number of hours devoted to substance use disorders training. Follow-up telephone surveys were conducted with faculty designated in the survey as responsible for substance-related disorders training to determine type of training and barriers to training.

RESULTS

Of 1,831 program directors, 1,183 (64.6%) responded to the brief survey. The percentage of programs with required substance use disorders training ranged from 31.8% in pediatrics to 95.0% in psychiatry, with 56.3% for all programs combined. The median number of curricular hours ranged from 3 (emergency medicine and OB/GYN) to 12 (family medicine). Time was perceived to be the most common barrier to additional training.

CONCLUSIONS

Consistent training for all residents in the initial diagnosis and management of substance use disorders has not been achieved. New strategies that integrate into existing residency structures are needed to improve substance use disorders training. Faculty development in substance use disorders and review of current substance use disorders training as part of the residency review process should facilitate this endeavor.

Low-resolution phase information in multiple-wavelength anomalous solvent contrast variation experiments

The basic theory and principles of the multiple-wavelength anomalous solvent-contrast (MASC) method are introduced as a contrast-variation technique for generating low-resolution crystallographic phase information on the envelope of a macromolecule. Experimental techniques and practical considerations concerning the choice of anomalous scatterer, sample preparation and data acquisition are discussed. Test cases of crystals of three proteins of differing molecular weights from 14 kDa through to 173 kDa are illustrated. Methods for extracting the moduli of the anomalous structure factors from the MASC data are briefly discussed and the experimental results are compared with the known macromolecular envelopes. In all cases, the lowest resolution shells exhibit very large anomalous signals which diminish at higher resolution, as expected by theory. However, in each case the anomalous signal persists at high resolution, which is strong evidence for ordered sites of the anomalous scatterers. For the smaller two of these proteins the heavy-atom parameters could be refined for some of these sites. Finally, a novel method for phasing the envelope structure-factor moduli is presented. This method takes into account the relatively low number of observations at low resolution and describes the macromolecular envelope with a small number of parameters by presuming that the envelope is a compact domain of known volume. The parameterized envelope is expressed as a linear combination of independent functions such as spherical harmonics. Phasing starts from solutions of a sphere in the unit cell after positional refinement from random trials and the parameters describing the envelope are then refined against the data of structure-factor moduli. The preliminary results using simulated data show that the method can be used to reconstruct the correct macromolecular envelope and is able to discriminate against some false solutions.

Seasonality of schizophrenia and stillbirths in The Netherlands

Studies from Denmark and the USA have reported a strong correlation between the seasonal pattern for stillbirths and the seasonal birth pattern for people who develop schizophrenia. It has been suggested that the correlation could be caused by a common seasonal factor (e. g. intra-uterine infections during the third trimester of pregnancy), which produces death in some fetuses and nonfatal brain changes in others, changes that are manifested in later life as schizophrenia. The aims of our study were (i) to assess the seasonal patterns for stillbirths and for pre-schizophrenic births in The Netherlands and (ii) to examine their relationship. The Dutch psychiatric registry provided data on all Dutch-born subjects who had been hospitalized at least once with a diagnosis of schizophrenia in the period 1970-1994. We selected data on patients born in the period 1926-1970 (n=29891). The government provided monthly numbers of live births and stillbirths in the latter period. Seasonality of birth was examined using Poisson regression analysis. The risk of an admission for schizophrenia was highest for people born in the months of May and June and lowest for those born in August and September. When the risk for subjects born in June was compared with the risk for subjects born in September, the Relative Risk was 1.14 [95% confidence interval (CI): 1.07 to 1.22]. The seasonal pattern of stillbirths was different, in that it showed a peak in the month of January. The low, however, as in schizophrenia, occurred in the months of August and September. The two seasonal patterns were found to be weakly correlated: Spearman's rank correlation coefficient rho=0.41 (95% CI: -0.22 to 0.80). This was the largest European study on birth seasonality in schizophrenia. The hypothesis that a common factor is responsible for a seasonal excess of stillbirths and for a seasonal birth excess of people who develop schizophrenia was not supported. The possibility remains, however, that a common factor explains seasonal (birth rate) deficits in these disorders.

Anomalous X-ray diffraction with soft X-ray synchrotron radiation

Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an uranium derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect the performance of the beamline ID1 of ESRF at wavelengths beyond 3 A at the end of 1998. A gain by a factor 100 for diffraction experiments with 4.4 A photons was achieved in Autumn 1999 when two focusing mirrors had been added to the X-ray optics. Further progress is expected from area detectors more sensitive to soft X-rays. Both CCD detectors and image plates would provide a gain of two orders of measured intensity. Image plates would have the additional advantage that they can be bent cylindrically and thus cover a larger solid angle in reciprocal space. In many cases, samples need to be cooled: closed and open systems are presented. A comparison with the state of art of soft X-ray diffraction, as it had been reached at HASYLAB (Hamburg, Germany), and as it is developing at the Brookhaven National Laboratory (USA), is given.

Interaction between the lipoamide-containing H-protein and the lipoamide dehydrogenase (L-protein) of the glycine decarboxylase multienzyme system 2. Crystal structures of H- and L-proteins

The glycine decarboxylase complex consists of four different component enzymes (P-, H-, T- and L-proteins). The 14-kDa lipoamide-containing H-protein plays a pivotal role in the complete sequence of reactions as its prosthetic group (lipoic acid) interacts successively with the three other components of the complex and undergoes a cycle of reductive methylamination, methylamine transfer and electron transfer. With the aim to understand the interaction between the H-protein and its different partners, we have previously determined the crystal structure of the oxidized and methylaminated forms of the H-protein. In the present study, we have crystallized the H-protein in its reduced state and the L-protein (lipoamide dehydrogenase or dihydrolipoamide dehydrogenase). The L-protein has been overexpressed in Escherichia coli and refolded from inclusion bodies in an active form. Crystals were obtained from the refolded L-protein and the structure has been determined by X-ray crystallography. This first crystal structure of a plant dihydrolipoamide dehydrogenase is similar to other known dihydrolipoamide dehydrogenase structures. The crystal structure of the H-protein in its reduced form has been determined and compared to the structure of the other forms of the protein. It is isomorphous to the structure of the oxidized form. In contrast with methylaminated H-protein where the loaded lipoamide arm was locked into a cavity of the protein, the reduced lipoamide arm appeared freely exposed to the solvent. Such a freedom is required to allow its targeting inside the hollow active site of L-protein. Our results strongly suggest that a direct interaction between the H- and L-proteins is not necessary for the reoxidation of the reduced lipoamide arm bound to the H-protein. This hypothesis is supported by biochemical data [Neuburger, M., Polidori, A.M., Piètre, E., Faure, M., Jourdain, A., Bourguignon, J., Pucci, B. & Douce, R. (2000) Eur. J. Biochem. 267, 2882-2889] and by small angle X-ray scattering experiments reported herein.

Feasibility and review of anomalous X-ray diffraction at long wavelengths in materials research and protein crystallography

The feasibility and a review of progress in the long-wavelengths anomalous dispersion technique is given in the context of the development of beamline ID1 of the ESRF for such studies. First experiments on this beamline and their analyses are described. The first study reports on the use of uranium which exhibits an unusually strong anomalous dispersion at its M(V) absorption edge (lambda(M(V)) = 3.5 A). The anomalous scattering amplitude of uranium with 110 anomalous electrons exceeds the resonance scattering of other strong anomalous scatterers like that of the rare earth ions by a factor of four. The resulting exceptional phasing power of uranium is most attractive in protein crystallography using the MAD method. The anomalous dispersion of a uranium derivative of asparaginyl-tRNA synthetase (hexagonal, a = 124.4 A, c = 123.4 A) has been measured at three wavelengths near the M(V) edge using beamline ID1 of the ESRF. The present set-up allowed the measurement of 10% of the possible reflections at a resolution of 8 A. This is mainly due to the low sensitivity of the CCD camera. The second study, involving DAFS experiments at wavelengths near the K-absorption edge of chlorine (lambda(K) = 4.4 A), reports the use of salt crystals which give rise to much stronger intensities of diffraction peaks than those of protein crystals. In the case of a crystal of pentamethylammonium undecachlorodibismuthate (PMACB, orthorhombic, a = 13.00 A, b = 14.038 A, c = 15.45 A), all reflections within the resolution range from 6.4 A to 3.5 A and the total scan width of 24 degrees were collected. The crystalline structure of PMACB implies two chemically distinct states of the Cl atom. Consequently, different dispersions near the K-edge of chlorine are expected. The dispersion of the intensity of five Bragg peaks of the PMACB crystal has been measured at 30 wavelengths. The relative success of these preliminary experiments with X-rays of long wavelength shows that the measurement of anomalous X-ray diffraction at wavelengths beyond 3 A is feasible. Starting from the experience gained in these experiments, an increased efficiency of the instrument ID1 by two to three orders of magnitude will be achieved in this wavelength range. A comparison with different techniques of anomalous diffraction which rely on the use of argon/ethane-filled multiwire chambers and image plates as detectors for wavelengths near the K-edge of sulfur and phosphorus is also given.

Endovascular grafts in the treatment of thoracic aortic aneurysms and pseudoaneurysms

The purpose of this study was to describe our experience with balloon and self-expanding endovascular grafts for the management of thoracic aortic lesions. Between February 1997 and June 1998, 20 endovascular grafts were implanted in 14 patients for the treatment of thoracic aortic aneurysms and pseudoaneurysms. Endovascular procedures were performed using one of four different devices: (1) Dacron-covered balloon-expandable Palmaztrade mark stent, (2) balloon-expandable Palmaz stent-PTFE graft prosthesis (BE-PS), (3) self-expanding internally supported Nitinol Dacron prosthesis (Vanguardtrade mark SE-V), and (4) self-expanding externally supported Nitinol PTFE prosthesis (Excludertrade mark SE-E). The results show that endovascular grafting represents a potentially important alternative therapy to open repair of the thoracic aorta. Self-expanding devices were, in our experience, easier to use and more accurately deployed.

International child health electives for pediatric residents

BACKGROUND

International child health (ICH) electives can strengthen the skills and shape the values of pediatric residents. Much can be learned from the literature on ICH electives during medical school. Yet there is little published information regarding ICH electives during residency, nor do educational guidelines for such electives exist.

OBJECTIVES

To describe existing ICH electives among pediatric residency programs and to develop guidelines for ICH electives during residency training.

PARTICIPANTS AND METHODS

A survey of 248 pediatric residency programs in the United States, Canada, and Puerto Rico was conducted in November 1995. Consensus guidelines were developed by the executive committee of the American Academy of Pediatrics (AAP) Section on International Child Health. Consensus was achieved via full agreement among the 11 committee members.

RESULTS

Survey response rate was 65%. International child health electives were offered by 25% of respondents. Most had no formal educational structure. An additional 42% of respondents indicated interest in ICH electives and requested more information. The AAP consensus guidelines for ICH electives focus on 4 principles: prerequisites, preceptorship, preparation, and evaluation. The guidelines are based on a conceptual framework that emphasizes reciprocity and continuity.

CONCLUSIONS

While only 25% of pediatric residency programs currently offer ICH electives, many more express an interest in doing so. Educational structure for such electives is important and lacking. The AAP consensus guidelines provide a template for meaningful ICH experiences during pediatric residency. These guidelines may be applicable to other specialties as well.