The fragile X in cattle

In search of an animal model for the human fragile X syndrome, the chromosomes of Holstein cows were examined. This breed was chosen because of previous studies on the baldy calf syndrome. An achromatic gap was observed at a specific site on the X chromosome closer to the centromere than that identified in humans. This unstained gap was found in 3%-4% of cells of the following four animals: an affected calf, her sister, their mother, and an unrelated Holstein cow. The bovine fragile X may not be analogous to the human fragile X but its location may be important as a genetic marker in linkage studies involving the loci for hypoxanthine phosphoribosyltransferase (HPRT) and glucose-6-phosphate dehydrogenase (G-6-PD).     

Molecular studies of non-disjunction in trisomy 16.

The origin of the additional chromosome in 26 trisomy 16 spontaneous abortions was studied using DNA probes for chromosome 16, including a probe for centromeric alpha sequences. We were able to determine the parent and meiotic stage of origin of trisomy in 22 cases, with all being attributable to maternal meiosis I non-disjunction. Furthermore, in each of the remaining four cases the results were compatible with this origin. Thus, it is likely that the high incidence of trisomy 16 results from an abnormal process acting at maternal meiosis I which more frequently involves chromosome 16 than other similar sized chromosomes. In studies of recombination, we found little evidence for an association between reduced or absent recombination and chromosome 16 non-disjunction; however, we were unable to rule out an effect of hyperrecombination.     

Randomized controlled trial of brief cognitive behaviour therapy versus treatment as usual in recurrent deliberate self-harm: the POPMACT study

BACKGROUND: We carried out a large randomized trial of a brief form of cognitive therapy, manual-assisted cognitive behaviour therapy (MACT) versus treatment as usual (TAU) for deliberate self-harm. METHOD: Patients presenting with recurrent deliberate self-harm in five centres were randomized to either MACT or (TAU) and followed up over 1 year. MACT patients received a booklet based on cognitive behaviour therapy (CBT) principles and were offered up to five plus two booster sessions of CBT from a therapist in the first 3 months of the study. Ratings of parasuicide risk, anxiety, depression, social functioning and global function, positive and negative thinking, and quality of life were measured at baseline and after 6 and 12 months. RESULTS: Four hundred and eighty patients were randomized. Sixty per cent of the MACT group had both the booklet and CBT sessions. There were seven suicides, five in the TAU group. The main outcome measure, the proportion of those repeating deliberate self-harm in the 12 months of the study, showed no significant difference between those treated with MACT (39%) and treatment as usual (46%) (OR 0.78, 95% CI 0.53 to 1.14, P=0.20). CONCLUSION: Brief cognitive behaviour therapy is of limited efficacy in reducing self-harm repetition, but the findings taken in conjunctin with the economic evaluation (Byford et al. 2003) indicate superiority of MACT over TAU in terms of cost and effectiveness combined.     

Differential expression of PD-L1 and PD-L2, ligands for an inhibitory receptor PD-1, in the cells of lymphohematopoietic tissues

PD-1 is a member of the immunoglobulin superfamily expressed on immune cells, including T and B cells, and is involved in the delivery of inhibitory signal upon engagement of its ligands, PD-L1 and PD-L2. While the expression profile of PD-1 has been well documented, the analysis of PD-L1 and PD-L2 distributions on a protein basis has not been carried out because of the lack of available monoclonal antibodies specific for the molecules. In this study, we established two monoclonal antibodies, 1-111A and 122, specific for murine PD-L1 and PD-L2, respectively, and examined their expression profiles. Based on flow cytometric analyses, the expression of PD-L1 was detected in a variety of lymphohematopoietic cell types, including a minor proportion of T and B cells in the spleen, majority of pre-B cells and myeloid cells in bone marrow and subsets of thymocytes, while the expression of PD-L2 was not observed in the lymphohematopoietic cells at all. Notably, a significant proportion of the most immature lineage-marker-negative and c-Kit-positive bone marrow cells containing stem cells did express PD-L1. Following mitogenic stimulation, essentially all lymphocytes expressed PD-L1. Furthermore, a variety of leukemic lines also expressed PD-L1, while none of them did PD-L2. Thus, present results demonstrate the distinct expression patterns of PD-L1 and PD-L2 with the cells of lymphohematopoietic tissues exclusively expressing the former.     

Induction of a differentiated ciliated cell phenotype in primary cultures of Fallopian tube epithelium

Human Fallopian tubal epithelial cells in culture lose morphological features associated with the epithelium in situ and the extent to which they retain their in-vivo phenotype or function is unknown. In order to address this question, immunocytochemical markers were identified which distinguish secretory (HMFG2+, LhS28-) from ciliated (HMFG2-, LhS28+) epithelial cells in tissue sections of Fallopian tube. These markers were used to analyse the phenotype of tubal cells in vitro. Primary cultures of human tubal epithelial cells were seeded onto glass and grown to confluence before addition of oestradiol-17beta. In the absence of hormone, tubal epithelial cells expressed cytokeratins and nuclear receptors for oestrogen and progesterone and adopted a homogeneous (HMFG2+, LhS28-) secretory cell phenotype. Following the addition of oestradiol-17beta, a proportion of cells became positive for LhS28. The induction of a ciliated epithelial cell phenotype was confirmed by scanning electron microscopy, where on permeable collagen membranes, approximately one-third of tubal epithelial cells became ciliated in the presence of oestradiol-17beta. We suggest that in vitro, tubal epithelial cells adopt an immature secretory-like phenotype and that oestrogen can induce differentiation to a ciliated epithelial cell phenotype.      

Practical Evaluation of Methods for Detection and Specificity of Autoantibodies to Extractable Nuclear Antigens

Detection and specificity of autoantibodies against extractable nuclear antigens (ENA) play a critical role in the diagnosis and management of autoimmune disease. Historically, the detection of these antibodies has employed double immunodiffusion (DID). Autoantibody specificity was correlated with diagnoses by this technique. Enzyme immunoassays have been developed by multiple manufacturers to detect and identify the specificity ENA autoantibodies. To address the relationship of ENA detection by DID and enzyme immunoassay, the performances of five immunoassays were compared. These included two DID and three enzyme-linked immunoassays (ELISA) (both screening and individual antigen profile kits). The sample set included 83 ENA-positive, antinuclear-antibody (ANA)-positive specimens, 77 ENA-negative, ANA-positive specimens, and 20 ENA- and ANA-negative specimens. Sensitivity and specificity were calculated by two methods: first, by using the in-house DID result as the reference standard, and second, by using latent class analysis, which evaluates each kit result independently. Overall, the results showed that the ELISA methods were more sensitive for detection of ENA autoantibodies than DID techniques, but presence and/or specific type of ENA autoantibody did not always correlate with the patient''s clinical presentation. Regardless of the testing strategy an individual laboratory uses, clear communication with the clinical staff regarding the significance of a positive result is imperative. The laboratory and the clinician must both be aware of the sensitivity and specificity of each testing method in use in the clinical laboratory.A diagnosis of autoimmune disease in patients is based upon clinical history, physical examination, and laboratory detection of antinuclear antibodies (ANAs). A particular class of ANAs specific for extractable nuclear antigens (ENA) was initially described in 1959 (3). Since that time, many different anti-ENA antibodies have been described. The detection of these autoantibodies and identification of their specificity have become well-established tools for the laboratory diagnosis of several autoimmune diseases. Studies of patients with ENA antibodies have shown that detection of these autoantibodies may have both diagnostic and prognostic significance, and the detection of anti-ENA antibodies has assumed an important role in the management of these patients (5, 16, 22). In most cases, ENA testing is ordered after an initial ANA screen. The indications for use are to establish a diagnosis in patients with suggestive clinical symptoms, to exclude a diagnosis of autoimmune disease in patients with few or uncertain clinical signs, to subclassify patients with a known diagnosis, and to monitor disease activity.Testing for anti-ENA antibodies has historically relied on gel-based immunoprecipitation techniques such as double immunodiffusion (DID) and counterimmunoelectrophoresis (2, 14). The associations of specific types of ENA autoantibodies with rheumatological diseases were established by using these gel-based immunoassay techniques (15). In the last decade, enzyme-linked immunoassay (ELISA) systems have been developed to detect and determine the specificity of anti-ENA antibodies. ELISA systems permit more rapid processing of more specimens with a faster turnaround time than gel-based assays. ELISA-based methods may also have increased sensitivity for detection of ENA antibodies. However, the increased sensitivity of these ELISAs may influence the clinical relevance of their detection because diagnostic specificity may be reduced (10, 12, 17, 24). As yet, a set of reference standards with known antibody specificities against defined antigen preparations is not available for evaluation of various methods or kits. Serum reference panels are available from the Association of Medical Laboratory Immunologists (4), but the specificities of these sera were determined by consensus results from multiple laboratories. The purpose of this study was to address the relationship between DID and ELISA methods for the detection and identification of anti-ENA antibodies by evaluating and comparing two DID kits and three ELISA kits. We evaluated both screening ELISAs and monospecific antigen ELISAs to determine anti-ENA specificity.     

A family study of bipolar I disorder in adolescence. Early onset of symptoms linked to increased familial loading and lithium resistance

Lifetime rates of psychiatric illness were compared in relatives of adolescent probands with bipolar I disorder and in relatives of age-matched schizophrenic controls. Familial aggregation of major affective disorders was observed in bipolar probands, the rate of bipolar I disorder greatly exceeding that reported in relatives of adult bipolar probands. Adolescent probands with childhood onset of psychiatric disturbance were distinguished from probands who had no premorbid childhood psychiatric abnormality in two ways: (1) significantly increased aggregation of bipolar I disorder in first-degree relatives; and (2) poorer antimanic response to lithium carbonate. These data underscore important heterogeneity in adolescent-onset bipolar disorder.     

Chaos and control in mass-action binding of endogenous compounds

Endogenous compounds, such as hormones and neurotransmitters, interact with cellular receptors in controlled reactions governed by the mass-action law. Autoreceptors, a subset of the receptor pool, when activated by the endogenous ligand, result in a negative feedback that reduces the further release of ligand. This paper discusses and illustrates this control system when the concentrations (free and bound) are near or slightly beyond the limits of effective feedback control. Specifically, a forced periodic input function, simulating periodic release of the ligand, is used in the simulation of this controlled binding reaction in which a parameter representing the upper limit of control is varied. The solution of the system differential equations, representing free and bound ligand, is shown to pass from periodic to chaotic as the parameter is varied.