Multiple cerebellar infarction due to vertebral artery obstruction and bulbar symptoms associated with vertical subluxation and atlanto-occipital subluxation in ankylosing spondylitis

Ankylosing spondylitis (AS) results in disease-specific inflammation at the site of ligamentous insertion into the bone. Atlantoaxial joint subluxation and vertical subluxation of the axis may occur as a consequence of instability resulting from the inflammatory process. Spontaneous anterior atlantoaxial subluxation is a well recognized complication in about 2% of patients with AS, and presents with or without signs of spinal cord compression. Vertical subluxation may follow anterior or posterior subluxation. It was noted in 3-8% of patients with rheumatoid arthritis, but is an exceedingly rare complication of AS. Moreover, it has never been reported that multiple cerebellar infarction and bulbar symptoms developed spontaneously due to atlanto-occipital subluxation and vertical subluxation in a patient with a long [corrected] history of AS. We describe a man with AS who developed multiple cerebellar infarction due to vertebral artery obstruction and bulbar symptoms associated with atlanto-occipital subluxation and vertical subluxation.     

The small-cell variant of mycosis fungoides. A clinicopathological and quantitative electron microscopic study on 14 patients

Small-cell variants of Sézary syndrome and mycosis fungoides (MF) have been described. However, in these studies the nuclear area of the small-cell variant of MF (SC-MF) as compared to histological classical MF (CL-MF) was not characterized objectively by quantitative electron microscopy. In a 14-year follow-up period, of a total of 76 patch/plaque stage MF patients seen in the Department of Dermatology of the University Hospital Utrecht, 14 (18%) had an infiltrate composed of atypical lymphocytes characterized by a distinctly smaller cell diameter and smaller, hyperchromatic, deeply indented nuclei as compared to the usual cell type of MF. The aim of the investigation was to confirm this observation objectively using quantitative electron microscopy (morphometry) and to define SC-MF as compared to CL-MF. The study was performed on the 14 patients with SC-MF, and 10 patients with clinical and histological CL-MF and 4 patients with chronic eczema. Electron micrographs of sections obtained from each biopsy were analysed by computer to produce the following data: a nuclear contour index (NCI), the mean nuclear area (MNA), the mean nuclear area of the cells above the 75th percentile (P75NA) and the percentage of cells larger than 30 microm2. The values of MNA differed significantly between patients with SC-MF and those with CL-MF (17.6 vs 23.2 microm2; P = 0.02), as did the values of P75NA (20.7 vs 27.9 microm2; P = 0.01). The NCI of the SC-MF and CL-MF patients were similar. These results are consistent with our observations that SC-MF does indeed exist.     

Measurement of the g-shift in superfluid3he-B

We have measured the g-shift in superfluid³He-B as a function of temperature above 0.5 mK at a pressure of 1.03 bar, and a frequency of 3.87 MHz. We compare our results with predictions of the quasi-classical and Ginzburg-Landau theories, and present values of the Fermi-liquid parameter F ₂ ^a and the -parameter ₃₄₅.     

The effect of fibre-matrix interactions on structure and property changes during the fabrication of unidirectional carbon/carbon composites

This paper reports the systematic characterisation of changes in the structure and properties of a series of unidirectional carbon-carbon composites at key stages of processing. The composites were fabricated from PAN-based carbon fibres (surface treated and untreated) and two carbon matrix systems (graphitising and non-graphitising). The effects of matrix shrinkage, together with thermal expansion mismatch and interfacial bonding, established the composite structure and hence the composite properties. The morphology and interconnectivity of the shrinkage cracks, the strength and nature of the fibre-matrix interfacial interaction and the development of matrix texture were identified as key structural features. These features were characterised and their effect on subsequent processing stages (densification) and composite properties was determined.     

Cognitive distortions and adolescent affective disorder. Validity of the CNCEQ in an inpatient sample. Children's Negative Cognitive Error Questionnaire

Despite a proliferation of recent research examining childhood and adolescent depression, the area still lags behind the adult depression field, particularly in the investigation of cognitive correlates of affective psychopathology. To advance cognitive research with youth, the Children's Negative Cognitive Error Questionnaire (CNCEQ) was developed to provide a measure of cognitive distortions or errors in children and adolescents. Yet, few studies have employed the CNCEQ and no evidence exists supporting the validity of its four component cognitive error scales. The purpose of the present study was to examine the construct validity of the CNCEQ and its constituent scales through the use of factor analysis and criterion-group comparisons. Groups of adolescent psychiatric inpatients, diagnosed as affective or disruptive disordered, completed the CNCEQ following admission. Results failed to support the implicit four-factor structure of the CNCEQ, instead suggesting the appropriateness of a single-factor solution labeled "negative thinking." Despite no diagnostic group differences on the CNCEQ total or other scale scores, affective disordered patients evinced more cognitive errors on the Overgeneralizing scale. Findings suggest that the CNCEQ in its current stage of development holds promise, yet requires refinement to produce a valid measure of cognitive functioning in youth.     

Psychosocial correlates of childhood anxiety disorders

OBJECTIVE: This study explored psychosocial and "environmental" correlates of childhood anxiety disorders. The study examined relationships among parental psychiatric symptomatology, perceived family environment, temperament, and self-competence in children with a DSM-III-R anxiety disorder. METHOD: A community sample of third through sixth graders was screened initially for symptoms of test anxiety. Those with high and low scores were administered the Anxiety Disorders Interview Schedule for Children. Three groups (childhood anxiety disorder, test-anxious only, and normal controls) were identified and compared on the psychosocial variables. RESULTS: Children with an anxiety disorder had greater impairment on the indices of perceived self-competence and temperamental flexibility than controls, with the test-anxious children showing intermediate, yet significant, levels of disturbance. There was a trend for children with an anxiety disorder to describe their families as less promoting of independence than the other groups. Finally, measures of parental psychiatric symptomatology revealed more obsessive-compulsive symptoms for the fathers of both the anxiety disorder and test-anxious children compared with controls. CONCLUSIONS: Results are consistent with previous findings suggesting the familial transmission of anxiety disorders and recent speculations regarding a relationship between behavioral inhibition, environmental control, and anxiety. Further research may isolate psychosocial and family environmental factors as instrumental treatment targets in the management of childhood anxiety disorders.     

First- and zero-sound velocity and fermi liquid parameter F 2 s in liquid3He determined by a path length modulation technique

We have measured the velocity of first- and zero-sound in liquid³He at 12.6 MHz over the pressure range of 0.6 to 14.5 bar using a path length modulation technique that we have recently developed. From these measurements, the pressure dependent value of the Fermi liquid parameter F ₂ ^s was calculated and found to be larger at low pressure than previously reported. These new values of F ₂ ^s indicate that transverse zero-sound is a propagating mode at all pressures. The new values are important for the interpretation of the frequencies of order parameter collective modes in the superfluid phases. The new acoustic technique permits measurements in regimes of very high attenuation with a sensitivity in phase velocity of about 10 ppm achieved by a feedback arrangement. The sound velocity is thus measured continuously throughout the highly attenuating crossover ( 1) regime, even at the lowest pressures.     

Learning of sequential movements in the monkey: process of learning and retention of memory

1. To characterize procedural learning and memory, we devised a behavioral paradigm that allows us to examine the process of learning of new procedures, repeatedly and without serious difficulties for primate subjects. We trained two monkeys to perform a sequential button press task. Upon pressing of a home key, 2 of 16 (4 x 4 matrix) light-emitting diode (LED) buttons (called "set") were illuminated simultaneously, and the monkey had to press them in a predetermined order that he had to find out by trial-and-error. A total of five sets (called "hyperset") was presented in a fixed order for completion of a trial; an error at any set aborted the trial. A given hyperset was repeated as a block of experiment until 20 successful trials were performed. Monkeys PI and BO experienced 313 and 92 hypersets, respectively. Most of these hypersets were experienced only once (1 block of experiment); the others (28 hypersets for monkey PI and 14 hypersets for monkey BO) were chosen for extensive practice. 2. The learning, indicated as the decrease in the number of trials to criterion and the decrease in the performance time, proceeded at three levels: 1) short-term and sequence-selective learning that occurred by repeating a particular hyperset during a block of experiment; our monkeys learned, to some degree, to perform a new hyperset within a short period (< 5 min); 2) long-term and sequence-selective learning that took place for each hyperset across days; by daily practice, they further improved their skills for performing the particular hyperset; and 3) long-term and sequence-unselective learning that was indicated by the improvement of performance for new hypersets; the monkeys were required to learn many hypersets, each just once (a block of trials), in which they performed gradually better with more experiences in the 2 x 5 task. 3. To examine whether the memory was retained for a long period, we had the monkey learn 12 hypersets sufficiently, then we stopped the training and retested them after 1 or 6 mo. After the 1-mo interruption the performance was significantly better than that for new hypersets. After the 6-mo interruption the performance was not different from new hypersets in terms of the number of trials but was significantly better than new hypersets in terms of the performance time. The results suggest that motor memory (measured by performance time) can be retained longer than procedural memory (measured by the number of trials).     

Isolation and characterization of a monoclonal anti-quadruplex DNA antibody from autoimmune "viable motheaten" mice

A cell line that produces an autoantibody specific for DNA quadruplex structures has been isolated and cloned from a hybridoma library derived from 3-month-old nonimmunized autoimmune, immunodeficient "viable motheaten" mice. This antibody has been tested extensively in vitro and found to bind specifically to DNA quadruplex structures formed by two biologically relevant sequence motifs. Scatchard and nonlinear regression analyses using both one- and two-site models were used to derive association constants for the antibody-DNA binding reactions. In both cases, quadruplexes had higher association constants than triplex and duplex molecules. The anti-quadruplex antibody binds to the quadruplex formed by the promoter-region-derived oligonucleotide d(CGCG4GCG) (Ka = 3.3 x 10(6) M-1), and has enhanced affinity for telomere-derived quadruplexes formed by the oligonucleotides d(TG4) and d(T2G4T2G4T2G4T2G4) (Ka = 5.38 x 10(6) and 1.66 x 10(7) M-1, respectively). The antibody binds both types of quadruplexes but has preferential affinity for the parallel four-stranded structure. In vitro radioimmunofilter binding experiments demonstrated that purified anti-DNA quadruplex antibodies from anti-quadruplex antibody-producing tissue culture supernatants have at least 10-fold higher affinity for quadruplexes than for triplex and duplex DNA structures of similar base composition and length. The antibody binds intramolecular DNA triplexes formed by d(G4T3G4T3C4) and d(C4T3G4T3G4), and the duplex d(CGCGCGCGCG)2 with an affinities of 6. 76 x 10(5), 5.59 x 10(5), and 8.26 x 10(5) M-1, respectively. Competition experiments showed that melted quadruplexes are not effective competitors for antibody binding when compared to native structures, confirming that the quadruplex is bound structure-specifically. To our knowledge, this is the first immunological reagent known to specifically recognize quadruplex structures. Subsequent sequence analysis demonstrates homologies between the antibody complementarity determining regions and sequences from Myb family telomere binding proteins, which are hypothesized to control cell aging via telomeric DNA interactions. The presence of this antibody in the autoimmune repertoire suggests a possible linkage between autoimmunity, telomeric DNA binding proteins, and aging.