[Internal carotid artery dissection after Heimlich maneuver]

We report a case of cervical artery dissection following a Heimlich maneuver. Cervical artery dissections are at the present time well known and are sometimes associated with trivial traumas. However, to our knowledge, this complication of such maneuver was never reported in the literature. Pathophysiological mechanisms are discussed.

[Aphasic hypergraphy in the course of a bilateral hemispheric glioblastoma]

A 68-year old patient, suffering from a left temporal and right frontal multifocal glioblastoma, initially presented Wernicke's aphasia with abnormal behavior. After a stereotaxic biopsy of his right frontal lesion, the patient developed an activity of ceaseless writing associated with mutism. This hypergraphic behavior was accompanied with a production of numerous aphasic paragraphics contrasting with the mutism. Such association could evoke the rise of a suppressive activity of the right hemisphere on graphic functions linguistically organized by the left hemisphere.

Chromosomal mapping of HCaRG, a novel hypertension-related, calcium-regulated gene

We recently identified a novel gene that is negatively regulated by extracellular calcium concentration with higher levels of transcripts in hypertensive animals (SHR). We named this gene HCaRG (Hypertension-related, Calcium-Regulated Gene). In this work we report the chromosomal localization of the HCaRG gene among different species. We identified a BglII RFLP between BN.lx and SHR rats. We then analysed the strain distribution pattern of this RFLP in 31 RIS, originating from BN.lx and SHR rats, and compared it to the segregation of 475 markers localized in the rat genetic map. Hcarg localizes to the rat chromosome 7 between the markers Mit3 and Mit4. This region is homologous to human chromosome 8q21-24. We identified three clones in Genbank that contain the sequence of HCaRG. It was therefore possible to narrow down the localization of human HCaRG to chromosome 8q24.3. Furthermore, a suggestive localization of mouse Hcarg based on conservation of linkage between human and mouse is on chromosome 15. We previously identified a putative calcium-binding motif (EF-Hand) and a nuclear receptor-binding domain (LxxLL) in the rat sequence of the HCaRG protein. Sequence comparison between five different species showed that these domains are highly conserved. Furthermore, a search of ESTs in Genbank for homologous sequences showed that HCaRG is expressed only in eukaryotes, particularly in mammals.

X-ray-induced debromination of nucleic acids at the Br K absorption edge and implications for MAD phasing

Multi-wavelength anomalous dispersion (MAD) using brominated derivatives is considered a common and convenient technique for solving chemically synthesized nucleic acid structures. Here, it is shown that a relatively moderate X-ray dose (of the order of 5 x 10(15) photons mm(-2)) can induce sufficient debromination to prevent structure determination. The decrease in bromine occupancy with radiation dose can be accounted for by a simple exponential, with an estimated rate constant at the absorption-peak wavelength, 7.4 (0.8) MGy, that is not significantly different from its value at the absorption-edge wavelength, 9.2 (2.6) MGy (the given e.s.d.s assess the relative closeness of the two values, not their absolute accuracy, which is probably worse). Chemically, these results (and others) are consistent with bromine cleavage resulting from direct photodissociation and/or from the action of free electrons, rather than from the action of hydroxyl radicals originating from water dissociation. The free bromine species (Br(-)) diffuse too quickly, even in amorphous ice around 100 K, to allow the determination of a diffusion coefficient. From a practical point of view, it is suggested that a single data collection with a crystal consisting of iodinated instead of brominated derivatives could provide both anomalous scattering and SIR phase information by the progressive cleavage of iodine.

[Hallucinations, delusions, and nocturnal events in 152 Parkinson's patients: a regional survey]

Parkinson's disease cannot be reduced to its motor symptoms. Psychological and behavioral disorders often accompany its development. Our study was conducted in June 1999 among 36 neurologists practicing in hospital or private clinic settings in the Poitou-Charentes area. Neurologists were requested to record hallucinations, delusions and nocturnal events observed in Parkinson's patients. A total of 152 reports were collected from 17 physicians. Fifty-three percent of the patients attended hospital clinics and 47p.100; were seen at the physician's office. Hallucinations were recorded in 23.1p.100; of the patients. The risk of hallucination symptoms was higher among patients seen at hospital clinics and who had more advanced disease. Only 7.2p.100; of the patients reported delusions, most often of a persecution type. Nocturnal events affected 49.3p.100; of the patients. The appearance of such symptoms was highly related to Hoehn and Yahr stage and was more frequent in hospital patients. Hallucinations, delusions, and nocturnal events affect patients with advanced Parkinson's disease, associated with long-term L-dopa treatment. Eighty-three percent of the patients had such symptoms and most of them used L-dopa. This long-term treatment is linked to these three symptoms. Hallucinations were increasingly reported for patients with increasing long-term medication with dopaminergic agonists. Nocturnal events, for patients on L-dopa, were associated with advanced disease, long-term treatment with L-dopa, and hospitalization. Psychic and behavioral disorders appear frequently in Parkinson's disease patients and are inter-related. Physicians should be aware of the relationship with treatment to avoid aggravation.

Stenting of bifurcation lesions: a rational approach

The occurrence of stenosis in or next to coronary bifurcations is relatively frequent and generally underestimated. In our experience, such lesions account for 15%-18% of all percutaneous coronary intervention > (PCI). The main reasons for this are (1) the coronary arteries are like the branches of a tree with many ramifications and (2) because of axial plaque redistribution, especially after stent implantation, PCI of lesions located next to a coronary bifurcation almost inevitably cause plaque shifting in the side branches. PCI treatment of coronary bifurcation lesions remains challenging. Balloon dilatation treatment used to be associated with less than satisfactory immediate results, a high complication rate, and an unacceptable restenosis rate. The kissing balloon technique resulted in improved, though suboptimal, outcomes. Several approaches were then suggested, like rotative or directional atherectomy, but these techniques did not translate into significantly enhanced results. With the advent of second generation stents, in 1996, the authors decided to set up an observational study on coronary bifurcation stenting combined with a bench test of the various stents available. Over the last 5 years, techniques, strategies, and stent design have improved. As a result, the authors have been able to define a rational approach to coronary bifurcation stenting. This bench study analyzed the behavior of stents and allowed stents to be discarded that are not compatible with the treatment of coronary bifurcations. Most importantly, this study revealed that stent deformation due to the opening of a strut is a constant phenomenon that must be corrected by kissing balloon inflation. Moreover, it was observed that the opening of a stent strut into a side branch could permit the stenting, at least partly, of the side branch ostium. This resulted in the provocative concept of "stenting both branches with a single stent." Therefore, a simple approach is currently implemented in the majority of cases: stenting of the main branch with provisional stenting of the side branch. The technique consists of inserting a guidewire in each coronary branch. A stent is then positioned in the main branch with a wire being "jailed" in the side branch. The wires are then exchanged, starting with the main branch wire that is passed through the stent struts into the side branch. After opening the stent struts in the side branch, kissing balloon inflation is performed. A second stent is deployed in the side branch in the presence of suboptimal results only. Over the last 2 years, this technique has been associated with a 98% angiographic success rate in both branches. Two stents are used in 30%-35% of cases and final kissing balloon inflation is performed in > 95% of cases. The in-hospital major adverse cardiac events (MACE) rate is around 5% and 7-month target vessel revascularization (TVR) is 13%. Several stents specifically designed for coronary bifurcation lesions are currently being investigated. The objective is to simplify the approach for all users. In the near future, the use of drug-eluting stents should reduce the risk of restenosis.

Crystal structures of coaxially stacked kissing complexes of the HIV-1 RNA dimerization initiation site

We describe the crystal structures of the RNA dimerization initiation sites (DIS) of HIV-1 subtypes A and B. Both molecules adopt a hairpin conformation, with loop sequences consisting of 272-AGGUGCACA-280 and 272-AAGCGCGCA-280, respectively. This includes a six-base self-complementary stretch (underlined) that allows homodimerization through the formation of a loop-loop, or 'kissing-loop', complex. The DISs for the two sequences have identical conformations, and the two interacting hairpins show a perfect coaxial alignment. The conserved purines, A272 and R273, are stacked in a bulged-out conformation and symmetrically join the upward and downward strands of each hairpin by crossing the helix major groove. There is good agreement between these structures and previous results from chemical probing in solution, as well as with differences in magnesium dependence for dimerization. The overall shape of the kissing-loop complex is very similar to that of the previously determined subtype A DIS duplex form. Unexpectedly, the purine R273 is the only base seen at a different position and is responsible for the difference in topology between the two forms. We propose that the transition from kissing-loop duplex could occur by a recombination mechanism based on symmetrical chain cleavage at R273 of each hairpin and subsequent cross-religation, rather than by base-pair melting and subsequent reannealing.

A genomic-systems biology map for cardiovascular function

With the draft sequence of the human genome available, there is a need to better define gene function in the context of systems biology. We studied 239 cardiovascular and renal phenotypes in 113 male rats derived from an F2 intercross and mapped 81 of these traits onto the genome. Aggregates of traits were identified on chromosomes 1, 2, 7, and 18. Systems biology was assessed by examining patterns of correlations ("physiological profiles") that can be used for gene hunting, mechanism-based physiological studies, and, with comparative genomics, translating these data to the human genome.

Coronary angiography using 4 or 6 French diagnostic catheters: a prospective, randomized study

Diagnostic catheter size has been progressively decreased in order to reduce complications (particularly access-site complications) and permit early ambulation after coronary angiography. However, excessive down-sizing can result in poor catheter conformation and poor imaging quality of coronary angiograms (CA). This study randomly compared the accuracy and angiographic quality (QUAL) of CA performed with 4 French (Fr) vs. 6 Fr diagnostic catheters. Injections were done manually using a low-viscosity, non-heated, low-osmolality contrast media (Iomeprol). CAs were performed via the femoral approach using Judkins catheters. Handling, torque, selectively and stability were graded from 1 (excellent) to 4 (unacceptable) by the operator. QUAL was also graded from 1 (unacceptable) to 10 (excellent) by the operator in all patients and by an independent Core laboratory in 50 patients matched for gender and weight. Between January and April 1997, a total of 405 consecutive patients were randomized. Mean age was 63.4 +/- 11.1 years and 79% were male. Clinical characteristics of patients, quality of left coronary catheter and cross-over rates (1.5% with 6 Fr vs. 3.9% with 4 Fr catheters) were similar in both groups. Using the right coronary catheters, the only difference was handling, which was found to be easier with 6 Fr catheters (1.16 +/- 0.55 vs. 1.34 +/- 0.77, respectively; p = 0.007). Similarly, handling difficulty using the pigtail catheter was the only significant difference between the two groups (1.16 +/- 0.50 vs. 1.33 +/- 0.77, respectively; p = 0.009), but no cross-over was necessary in either group. The QUAL of CA was slightly but significantly better with 6 Fr than with 4 Fr catheters but considered non-diagnostic (< 7/10) in 1.4% vs. 6.8% of left CAs (p = NS). Procedural time (21.0 +/- 7.2 minutes vs. 19.0 +/- 8.1 minutes; p = 0.007) was shorter with 4 Fr catheters, but x-ray exposure, compression times and amount of contrast media used were similar. Ambulation was obtained at 2 hours in 15.1% vs. 34.0% of patients (p < 0.001) and at 4 hours in 43.8% vs. 52.4% (p < 0.05), respectively. The incidence of the worst access-site complication (moderate hematoma) was similar (1%) in both groups. CA can be performed using 4 Fr catheters and manual injections of low-viscosity contrast media with acceptable angiographic results in the majority of cases. This is associated with a shorter procedural time and earlier ambulation, and a decreased but acceptable angiographic quality.

Detailed analysis of RNA-protein interactions within the ribosomal protein S8-rRNA complex from the archaeon Methanococcus jannaschii

The crystal structure of ribosomal protein S8 bound to its target 16 S rRNA from a hyperthermophilic archaeon Methanococcus jannaschii has been determined at 2.6 A resolution. The protein interacts with the minor groove of helix H21 at two sites located one helical turn apart, with S8 forming a bridge over the RNA major groove. The specificity of binding is essentially provided by the C-terminal domain of S8 and the highly conserved nucleotide core, characterized by two dinucleotide platforms, facing each other. The first platform (A595-A596), which is the less phylogenetically and structurally constrained, does not directly contact the protein but has an important shaping role in inducing cross-strand stacking interactions. The second platform (U641-A642) is specifically recognized by the protein. The universally conserved A642 plays a pivotal role by ensuring the cohesion of the complex organization of the core through an array of hydrogen bonds, including the G597-C643-U641 base triple. In addition, A642 provides the unique base-specific interaction with the conserved Ser105, while the Thr106 - Thr107 peptide link is stacked on its purine ring. Noteworthy, the specific recognition of this tripeptide (Thr-Ser-Thr/Ser) is parallel to the recognition of an RNA tetraloop by a dinucleotide platform in the P4-P6 ribozyme domain of group I intron. This suggests a general dual role of dinucleotide platforms in recognition of RNA or peptide motifs. One prominent feature is that conserved side-chain amino acids, as well as conserved bases, are essentially involved in maintaining tertiary folds. The specificity of binding is mainly driven by shape complementarity, which is increased by the hydrophobic part of side-chains. The remarkable similarity of this complex with its homologue in the T. thermophilus 30 S subunit indicates a conserved interaction mode between Archaea and Bacteria.

Outcome after combined reperfusion therapy for acute myocardial infarction, combining pre-hospital thrombolysis with immediate percutaneous coronary intervention and stent

BACKGROUND

Primary therapies in acute myocardial infarction (thrombolysis and angioplasty) have inherent limitations which may be overcome by combining them. So far, no trial has demonstrated a clinical benefit in combining mechanical and pharmacological treatment strategies.

METHODS

From January 1995 to December 1999, out of 1010 patients admitted to our institution for acute myocardial infarction, 148 had received pre-hospital full dose thrombolysis within 12 h of onset. One hundred and thirty-one patients were included and underwent immediate angioplasty and stenting when suitable, independent of the infarct-artery patency (TIMI grade flow 0-3). In-hospital outcome was assessed and clinical information was collected for a mean (+/-SD) of 2+/-1 years.

RESULTS

Ninety-minute angiography revealed a patent (TIMI grade 3) infarct artery in 65 patients (49%). Immediate angioplasty was performed in 119 patients (91%) with stent implantation in 114 (96%). Angioplasty achieved TIMI 2, 3 flow in 98%, and complete patency (TIMI 3 flow) in 92%. Six other patients underwent deferred revascularization (surgery in one patient, angioplasty in five) and six received medical treatment. Stent thrombosis and reinfarction occurred in three patients (2.3%). In-hospital death occurred in six patients (4.6%), including four patients presenting with cardiogenic shock. Major bleeding was observed in 2.3% of cases. No patient had emergency surgery. Freedom from death and reinfarction at 2 years was 90% and freedom from death, reinfarction and target vessel revascularization was 83%.

CONCLUSION

A strategy of combined reperfusion using full dose pre-hospital thrombolysis and immediate angioplasty with stent implantation in a non-selected acute myocardial infarction population is safe and achieves high and early patency rates. This preliminary experience suggests that a combined strategy in acute myocardial infarction may have a significant impact on both early and long-term outcomes.

[Anterior compartment syndrome of the forearm caused by exercise: unusual cause of recurrent episodes of acute effort rhabdomyolysis]

INTRODUCTION

An effort-related compartmental syndrome is well known in the leg, but may be present infrequently, acutely or chronically in the anterior compartment of the forearm.

EXEGESIS

We report a case of a 32-year-old man who presented four times after climbing exercises a bilateral compartment of the forearm, unusual because of the observation of rhabdomyolysis, but without irreversible damage. Clinical information and follow-up on two acute and 14 chronic cases were reexamined, showing a homogenous presentation. He refused fasciotomy because he stopped athletic activities. Measurement of intramuscular pressure after exertion was useful for diagnosis.

CONCLUSION

A local effort-related pain must call to mind a chronic compartment syndrome of the forearm, which may risk incurring the acute form, with irreversible lesions of muscle and nerve, and possibly renal failure because of rhabdomyolysis.

Phase I and pharmacokinetic study of exatecan mesylate (DX-8951f): a novel camptothecin analog

PURPOSE

To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetic (PK) profile, and recommended phase II dose of Exatecan mesylate (DX-8951f) when administered as a 24-hour continuous infusion every 3 weeks to patients with solid tumors.

PATIENTS AND METHODS

Twenty-two patients with advanced solid tumors, all previously treated, and with performance status < or = 2, were entered. The starting dose of DX-8951f was 0.15 mg/m(2); the dose was escalated according to the modified continual reassessment method. The drug was administered until disease progression or until unacceptable toxic effects occurred.

RESULTS

Seven dose escalations were completed, and a total of 53 courses were delivered (median, two courses; range, one to eight courses) during the study. At doses 1.2 mg/m(2) and lower, toxicities were mostly grade 1, primarily hematologic. In the initial cohort of three patients treated at 2.4 mg/m(2), grade 2 hematologic toxicity was observed. Of the six additional patients entered at 2.4 mg/m(2), three had grade 3 or 4 granulocytopenia. At doses higher than 2.4 mg/m(2), DLT granulocytopenia was observed. Nonhematologic toxicities, including nausea, vomiting, diarrhea, fatigue, and alopecia, were mild to moderate. Neither complete nor partial responses were observed, but four patients had stable disease. The PK profile of DX-8951f seemed linear at the doses administered. The plasma clearance, total volume of distribution, and terminal elimination half-life were approximately 3 L/h, 40 L, and 14 hours, respectively.

CONCLUSION

The DLT of this DX-8951f schedule was granulocytopenia for minimally pretreated patients, and both granulocytopenia and thrombocytopenia for heavily pretreated patients. The MTD for both minimally and heavily pretreated patients was 2.4 mg/m(2). DX-8951f seems to have a linear PK profile on the basis of single-dose administration. The recommended phase II dose with this schedule is 2.4 mg/m(2) for minimally pretreated patients. A lower dose should be used for heavily pretreated patients.

[Vulnerability to schizophrenia: neuropsychological performance and schizotypal personality traits]

Although some neuropsychological deficits and a high rate of schizotypal personality disorders have been found in the first-degree relatives of patients with schizophrenia, few studies have looked for a link between those two types of potential marker of vulnerability to this disease. The aims of this study were: 1) to confirm some executive/attentional deficits in a group of first-degree relatives including not only siblings but also parents; 2) to evaluate the schizotypal traits using the French version of 4 self-reporting scales proposed by Chapman and his colleagues; 3) to look for a dependence or independence between the neuropsychological performance and the scores on the scales of schizotypy. Twenty four patients with schizophrenia, 48 of their first-degree relatives and 31 controls were included in the study. Both attentional tests (a Digit Symbol Substitution Test and a Degraded Stimulus-Continuous Performance Test) confirmed a worse performance in the patient and in the first-degree relative groups than in the control group. On the opposite side, the executive performance assessed by the Wisconsin Sorting Card Test, was poorer in the patient group only. Scores of the first-degree relative group on the social anhedonia, physical anhedonia and perceptual aberrations scales were at an intermediate level between those of the patient and control groups; moreover, only scores on the social anhedonia scale tended to be significantly higher in the first-degree relative group than in the control group. Among the first-degree relative group, the only significant correlation found was between the number of perseverative errors on the WCST and the scores on the physical anhedonia scale.

Workshop: excess growth and apoptosis: is hypertension a case of accelerated aging of cardiovascular cells?

Several groups including ours have demonstrated cardiac hyperplasia in neonates from genetically hypertensive rat strains. We have shown that similar problems exist in the kidney as well. More recently, we found that excessive heart and kidney weight is neonatally related to inhibition of apoptosis. Using recombinant inbred strains derived from a reciprocal cross between Brown Norway and spontaneously hypertensive rat progenitor strains, we mapped the inhibition of neonatal apoptosis to 2 distinct loci on chromosomes 1 (Myl 2) and 18 (Abrb 2). Positional candidate genes at these loci are being explored. These studies have also demonstrated that the loci determining kidney and heart weights in neonates are distinct from those determining increased organ weight in adults. The impact of blood pressure per se is also divergent because adult kidney weight is negatively correlated whereas heart weight is positively correlated with it. Analyses by extremes of low and high percentiles from fetal life to adulthood identified a single locus determining heart weight at Acaa on chromosome 8 in newborn (P=0.0003) and adult (P=0.016) rats. The Acaa region contains a DNA mismatch repair gene (hMLH1). The kinetics of neonatal growth through adulthood by prelabeling DNA with [(3)H]thymidine in pregnant mares showed that although the growth process is complex and nonlinear in the kidney of hypertensive rats, there is an increased turnover of cells, that is, reduced half-life of DNA. This observation is supported by the presence of shorter telomere fragments in kidneys of spontaneously hypertensive rats. These studies suggest that cardiovascular cells from hypertensive animals are subject to accelerated turnover, potentially leading to their accelerated aging.

Brown Norway chromosome 13 confers protection from high salt to consomic Dahl S rat

Consomic rats (SS.BN13), in which chromosome 13 from normotensive inbred Brown Norway rats from a colony maintained at the Medical College of Wisconsin (BN/Mcw) was introgressed into the background of Dahl salt-sensitive (SS/Mcw) rats, also maintained in a colony at the Medical College of Wisconsin, were bred. The present studies determined the mean arterial pressure (MAP) responses to salt and renal and peripheral vascular responses to norepinephrine and angiotensin II; 24-hour protein excretion and histological analyses were used to assess renal pathology in rats that received a high salt (4% NaCl) diet for 4 weeks. MAP of rats measured daily during the fourth week averaged 170+/-3.3 mm Hg in SS/Mcw rats, 119+/-2.1 mm Hg in SS.BN13 rats, and 103+/-1.3 mm Hg in BN/Mcw rats. After salt depletion, MAP fell an average of 27+/-4.5 mm Hg in SS/Mcw rats, 9+/-2.6 mm Hg in SS.BN13 rats, and 11+/-3.0 mm Hg in BN/Mcw rats. Protein excretion of SS/Mcw rats on a high salt diet averaged 189+/-30 mg/24 h, 63+/-18 mg/24 h in SS.BN13 rats, and 40+/-6.4 mg/24 h in BN/Mcw rats. Compared with SS.BN13 and BN/Mcw rats, SS/Mcw rats exhibited significantly greater increases of renal vascular resistance in response to intravenous norepinephrine and angiotensin II. Severe medullary interstitial fibrosis and tubular necrosis after a high salt diet were found consistently in SS/Mcw rat kidneys but were largely absent in the SS.BN13 and BN/Mcw rat kidneys. A similar degree of glomerular sclerosis was found in both SS/Mcw and SS.BN13 rats. In rats fed a 0.4% salt diet, the glomerular filtration rate of SS/Mcw rats was significantly less than that of BN/Mcw and SS.BN13 rats. These results reveal a powerful gene, or set of genes, within chromosome 13 of BN/Mcw rats that confers protection from the detrimental effects of high salt to the SS/Mcw rats.

Systematic use of transradial approach or suture of the femoral artery after angioplasty: attempt at achieving zero access site complications

Access site complications occur in 5-15% of cases according to the various series. The predictive factors most often reported in the literature are the size of the puncture site and the intensity of the antiplatelet or anticoagulant treatment associated with the angioplasty procedure. Six senior cardiologists in a high volume Cardiology center (>1,500 procedures a year) with an individual experience >500 procedures in either the radial approach or the percutaneous suture of the femoral artery with the Techstar/Prostar system, conducted a prospective study from January 1 to December 31, 1999. The aim of this study was to eliminate the occurrence of access site complications by using either one of two techniques that were at the operator's discretion, i.e., systematic radial approach, or percutaneous suture of the femoral artery. A total of 956 patients were included over the study period; 60.7% of these patients had percutaneous arterial closure of the femoral artery and the remaining 39.3% were treated via the radial approach; 88.7% were stented. The patients were administered a mean 9,000 IU of heparin during the procedure; 1.9% had been fibrinolyzed and Reopro was used in 5.9%. No complications were documented in the radial group. Of the 580 patients in the femoral suture group, 96.9% had femoral suture, immediately effective in 508 cases (90.4%). Only 3 patients required additional prolonged compression. One significant hematoma (0.2%) necessitating blood transfusion was reported in the femoral group. Infection at the puncture site with subsequent antibiotic treatment was reported in 2 patients (0.3%). No further access site complications were observed at one-month follow-up. After completion of the learning curve, the two techniques (radial approach and percutaneous arterial suture) permit the almost total elimination of access site complications.

The crystal structure of UUCG tetraloop

All large structured RNAs contain hairpin motifs made of a stem closed by several looped nucleotides. The most frequent loop motif is the UUCG one. This motif belongs to the tetraloop family and has the peculiarity of being highly thermodynamically stable. Here, we report the first crystal structure of two UUCG tetraloops embedded in a larger RNA-protein complex solved at 2.8 A resolution. The two loops present in the asymmetric unit are in a different crystal packing environment but, nevertheless, have an identical conformation. The observed structure is globally close to that obtained in solution by nuclear magnetic resonance. However, subtle differences point to a more detailed picture of the role played by 2'-hydroxyl groups in stabilising this tetraloop.

The crystal structure of HIV reverse-transcription primer tRNA(Lys,3) shows a canonical anticodon loop

We have solved to 3.3 A resolution the crystal structure of the HIV reverse-transcription primer tRNA(Lys,3). The overall structure is exactly comparable to the well-known L-shape structure first revealed by yeast tRNA(Phe). In particular, it unambiguously shows a canonical anticodon loop. This contradicts previous results in short RNA fragment studies and leads us to conclude that neither frameshifting specificities of tRNA(Lys) nor tRNA(Lys,3) primer selection by HIV are due to a specific three-dimensional anticodon structure. Comparison of our structure with the results of an NMR study on a hairpin representing a nonmodified anticodon stem-loop makes plausible the conclusion that chemical modifications of the wobble base U34 to 5-methoxycarbonyl-methyl-2-thiouridine and of A37 to 2-methylthio-N-6-threonylcarbamoyl-adenosine would be responsible for a canonical 7-nt anticodon-loop structure, whereas the unmodified form would result in a noncanonical UUU short triloop. The hexagonal crystal packing is remarkable and shows tight dimers of tRNAs forming a right-handed double superhelix. Within the dimers, the tRNAs are associated head-to-tail such that the CCA end of one tRNA interacts with the anticodon of the symmetry-related tRNA. This provides us with a partial view of a codon-anticodon interaction and gives insights into the positioning of residue 37, and of its posttranscriptional modifications, relative to the first base of the codon.

[Validation of the French version of the Raine Schizotypal Personality Disorder Questionnaire--categorial and dimensional approach to schizotypal personality traits in a normal student population]

Most of existing self-report measures of schizotypal personality assess only few of the nine traits of Schizotypal Personality Disorder (SPD) according to DSM III-R or DSM IV. The Raine's Schizotypal Personality Questionnaire (SPQ) is one of the most widely used questionnaire for SPD diagnosis. This well adapted tool for screening SPD in large samples from general population allows simple and quick evaluations by the mean of 74 items and nine sub-scales exploring DSM IV criteria of the trouble. With the original sample of American students, Raine found SPQ to have high internal reliability (0.91) and reported cutoffs for the top and the bottom ten percents of SPQ scores at respectively 41/74 and 12/74. We reported here the validation study of the French version of the SPQ in a sample of 232 students (males: n = 107; females: n = 125; mean age: 21.17 +/- 1.47; mean educational level: 13.36 +/- 1.06). The French version has high internal reliability (SPQ total: Cronbach's alpha = 0.91; SPQ nine subscales: Cronbach's alpha = 0.57 to 0.76). The ten percent high and low cutoff scores on the distribution of SPQ scores are respectively 40/74 and 7/74 for the total sample. However, gender differences are observed: 38/74 and 9/74 for females; 42/74 and 6/74 for males. A Principal Component Analysis (PCA) confirms the high internal reliability. Moreover, PCA evidences a three-factor model of schizotypy reflecting "positive or cognitive-perceptual", "negative or social-interpersonal", and "disorganization" latent factors. These results replicate previous works on the topic with the same instrument.