The immunopathology of M cells

Conclusions Mucosal epithelia have two functions, which at first glance seem at variance with each other — maintenance of a barrier and uptake of antigens. The M cell is a unique solution to this problem. However, it also provides many mucosal and systemic pathogens with a convenient portal of invasion, and may also be the point of uptake of detrimental antigens, such as carcinogens and those that induce autoimmune disease. Much remains unknown about the functions of M cells and the precise nature of their interactions with pathogens. Determinants of pathogen tropism for M cells, in particular anatomic sites, must be elucidated before we can proceed to the task of modulating M cell antigenic uptake to enhance absorption and presentation of vaccines and to reduce systemic penetration of allergens and pathogenic microorganisms. Research in this area would be considerably advanced by the development of techniques to induce and maintain differentiated M cells in vitro, and the production of monoclonal antibodies specific for cells of this lineage. Irrespective of these gaps in our current knowledge, it has become increasingly apparent that the M cell may be of paramount importance in the initiation of colonization by many, if not all, important human and animal mucosal pathogens.     

Rapid determination of trisomy 18 parental origin using fluorescent PCR and small tandem repeat markers: case reports

Trisomy 18 is the second most common genetic defect after trisomy 21, almost 90% of which are due to additional chromosome from the mother. The parental origin of the additional chromosome can, if required, be determined by two methods: karyotyping, which takes several weeks; or, more recently, by polymerase chain reaction (PCR) which is often problematic. Fluorescent PCR of small tandem repeats (STRs) can determine the parental origin in the majority of cases within 5 h. Although the incidence of paternal origin is known for both trisomy 21 and trisomy 18, this technique can rapidly determine the parental origin in cases where there is insufficient samples to perform conventional tests. Determining parental origin by these methods may also have clinical significance in the diagnosis of chromosomal translocations or in the diagnosis of genetic disease using linkage analysis.     

Three antidepressants (amitriptyline,dothiepin, fluoxetine), with and without alcohol,compared with placebo on tests of psychomotor ability related to car driving

Eight female volunteers received acute doses of amitriptyline 50 mg (AMI), dothiepin 50 mg (DOT), fluoxetine 40 mg (FLU) or placebo both with and without a ‘social’ dose of alcohol (ALC) equivalent to 0·5 g/kg body weight absolute alcohol. Performance on a variety of tests of psychomotor ability and cognitive function (critical flicker fusion, choice reaction time, tracking, Maddox Wing and simulated car steering) were performed at 1·5 and 4 hours following treatment. AMI and DOT both with and without ALC impaired performance on a range of tests at either or both 1·5 and 4 hours, although the effects of AMI and AMI + ALC were more widespread and severe than those found with either DOT or DOT + ALC. FLU and FLU + ALC showed no evidence of impairment on any test at either the 1·5 or the 4 hours assessments. The results suggest that there are differences between the experimental substances, at the doses used, in their intrinsic potential for impairing aspects of psychomotor performance and cognitive function.