B7/BB-1 is a leucocyte differentiation antigen on human dendritic cells induced by activation.

Activation of a primary T-lymphocyte response requires additional signals apart from interaction of the T-cell receptor (TcR)/CD3 complex with major histocompatibility complex (MHC) antigens on the antigen-presenting cell. The CD28 antigen on T lymphocytes provides an important co-stimulatory signal to T lymphocytes and we therefore searched for the presence of its ligand, the B7/BB-1 antigen, on blood and tonsil dendritic cells (DC). Blood DC, prepared from peripheral blood mononuclear cells with a minimal period of in vitro culture, did not stain with the monoclonal antibody BB-1 using flow cytometry analysis. In contrast, tonsil DC stained weakly for B7/BB-1 compared to positive control cell lines. Polymerase chain reaction (PCR) was used to amplify a 605 base pair (bp) fragment from human B7/BB-1 mRNA and demonstrated significant amounts of B7/BB-1 mRNA in tonsil DC but no specific product was obtained from blood DC, confirming the surface-staining results. Weak expression of B7/BB-1 antigen was detected by immunofluorescence analysis following culture of blood DC with either interferon-gamma (IFN-gamma) or granulocyte-macrophage colony-stimulating factor (GM-CSF). These data support the concept that blood DC give rise to tissue and/or lymphoid DC, which acquire co-stimulatory ligands as a result of activation and/or differentiation.     

Coeliac disease, adenocarcinoma of jejunum and in situ squamous carcinoma of oesophagus

The development of both adenocarcinoma of the jejunum and in situ squamous carcinoma of the oesophagus in an adult coeliac patient is described. Good evidence that adenocarcinoma of jejunum occurs more frequently in patients with coeliac disease has recently become available though this association has been suggested for some time. While oesophageal carcinoma has long been associated with coeliac disease, in situ carcinoma of oesophagus has not been previously described in these circumstances. We feel that the risk of this complication, as calculated from published series, warrants a screening programme for oesophageal malignancy in adult coeliacs.     

Cell types required for anti-acetylcholine receptor antibody synthesis by cultured thymocytes and blood lymphocytes in myasthenia gravis.

In most young myasthenia gravis patients, the thymic medulla contains germinal centres. Thymocytes from these cases spontaneously synthesize anti-acetylcholine receptor autoantibody (anti-AChR) in culture; after irradiation they may also selectively stimulate anti-AChR antibody production by autologous blood lymphocytes. By depleting cortical or mature thymic T cells by complement killing, we now show that neither of these responses depends on thymic T cells, unlike the total IgG response to pokeweed mitogen which is T cell-dependent and shows T/B cell synergy. The results suggest that much of the spontaneous anti-AChR production is by autonomous thymic plasma cells, which may be HLA-DR-. The ability to stimulate autologous blood lymphocytes does not require viable HLA-DR+ thymic cells but appears to depend on rare antigen presenting cells from the germinal centres. In preliminary experiments, blood T cells were apparently also necessary.     

Facial expression recognition by people with mobius syndrome

We present an investigation of facial expression recognition by three people (BC, LP, and NC) with Mobius syndrome, a congenital disorder producing facial paralysis. The participants were asked to identify the emotion displayed in 10 examples of facial expressions associated with each of 6 basic emotions from the Ekman and Friesen (1976) series. None of the three people with Mobius syndrome was significantly impaired on this task. On a second test of facial expression recognition using computer-morphed facial expressions, NC showed a statistically significant impairment, BC a borderline deficit, and LP was unimpaired. However, even when impairments were found, people with Mobius syndrome still recognised many of the facial expressions shown to them. The recognition of facial expressions by people who have never been able to produce such signals on their own faces demonstrates that the ability to produce facial expressions is not a necessary prerequisite of their recognition.     

Predictive value of normal sperm morphology: a structured literature review

The aim of the study was to conduct a structured review of theliterature published on the use of normal sperm morphology,as an indicator of male fertility potential in the in-vitrofertilization (IVF) situation, and to establish the universalpredictive value of this semen parameter. Published literaturein which normal sperm morphology was used to predict fertilizationand pregnancy, during the period 1978-1996, was reviewed. Atotal of 216 articles were identified by the sourcing methodology,but only 49 provided data that could be tabulated and analysed.Of these, only 18 provided sufficient data for statistical analysis.Fifteen studies used the strict criteria to evaluate sperm morphology,two used World Health Organization (WHO) guidelines and oneused both the strict criteria and the WHO guidelines. All thestudies (n=10) using the 5 and 14% normal sperm morphology thresholds(strict criteria) produced positive predictive values for IVFsuccess. In the prediction of pregnancy, 82% (9/11) and 75%(6/8) of the studies produced positive predictive values whenusing the 5% and 14% thresholds respectively. Aggregating thedata produced around the 5% normal sperm morphology threshold(strict criteria), the overall fertilization rates were 59.3%(1979/3337; per oocyte) for the 4% group and 77.6% (10345/13327;per oocyte) for the >4% group, and the overall pregnancyrates were 15.2% (60/395; per cycle) and 26.0% (355/1368; percycle) respectively. The no-transfer rates across the 5% thresholdwere 24.0% (86/359; per cycle) in the 4% group compared to 7.4%(80/1088; per cycle) in the >4% group. The inclusion of anaccurately evaluated normal sperm morphology count as an integralpart of the standard semen analysis makes this analysis stillthe most cost-effective means of evaluating the male factor.     

Anti-acetylcholine receptor antibodies induced in mice by syngeneic receptor without adjuvants.

Acetylcholine receptor (AChR)-bearing membranes from the BC3H-1 cell lines were injected, without adjuvant, either intrathymically (i.t.) followed by intraperitoneal (i.p.) booster doses, or i.p. alone, into (C57BL X BALB/c)F1 mice. Over 75% of the animals developed serum anti-AChRs which reacted with the cell-line AChR and with normal mouse endplate AChR. The titres were within the lower range of those of myasthenia gravis patients, and some mice showed reduced miniature endplate potential (m.e.p.p) amplitudes. these results indicate that loss of tolerance to acetylcholine receptors can result from immunization against syngeneic AChR without adjuvant. This approach may provide a useful model for studying mechanisms of autoimmunity against acetylcholine receptor.