The ion exchange properties of human post-mortem caecal and colonic mucus: The effect of sodium butyrate

This study examined Na+/H+ ion exchange of caecal and colonic mucus. Two distinct Na+/H+ ion exchange populations of caecal mucus were identified, one group being a cation exchanger and the other an anion exchanger, suggesting that caecal mucus has ampholyte properties responsive to changing physical and chemical properties of luminal contents. Mucus from the colon was consistently an anionic exchanger--this may aid water and electrolyte absorption in the colon. When mucus was incubated with sodium butyrate, the Na+/H+ ion exchange properties of the mucus were decreased.     

Review: Glial lineages and myelination in the central nervous system

Oligodendrocytes, derived from stem cell precursors which arise in subventricular zones of the developing central nervous system, have as their specialist role the synthesis and maintenance of myelin. Astrocytes contribute to the cellular architecture of the central nervous system and act as a source of growth factors and cytokines; microglia are bone-marrow derived macrophages which function as primary immunocompetent cells in the central nervous system. Myelination depends on the establishment of stable relationships between each differentiated oligodendrocyte and short segments of several neighbouring axons. There is growing evidence, especially from studies of glial cell implantation, that oligodendrocyte precursors persist in the adult nervous system and provide a limited capacity for the restoration of structure and function in myelinated pathways damaged by injury or disease.     

The cognitive effects of alcohol abuse: a controlled study

It is now well established that there is an association between excessive alcohol consumption and psychological impairment. However, there has been some difficulty in the interpretation of results as the majority of studies have relied on reporting correlations in large subject samples. It was felt therefore that if subjects were matched by variables which had been found to be confounding in previous research, a clearer picture of the effects of alcohol on cognitive functioning could be drawn. Subjects in this study were therefore divided into a ‘high’ alcohol group (over 50 units per week), and a ‘low’ alcohol group (under 20 units per week). No patients who had previously been reported as suffering from cognitive impairment were included in this study as the purpose of this research was to examine the effects of alcohol on those heavy drinkers with no obvious impairment. They were matched by age, sex, socio-economic status and educational background. Heavy drinkers showed significant deficits on a number of cognitive tests compared with their matched controls. Furthermore, the subjects in the lower educational group showed a greater decrease in scores on several sub tests than those in the higher group.     

Magnetic resonance imaging as a screening procedure for methotrexate induced liver damage

Spin lattice relaxation time (TI) measured with a low field strength magnetic resonance imager in 51 patients with severe psoriasis did not correlate with the histological findings of liver biopsies taken during treatment with oral methotrexate. Liver TI measurement at low magnetic field is of no value as a screening procedure in monitoring methotrexate induced liver damage.     

Inpatient and long‐term outcomes of individuals admitted for weaning from mechanical ventilation at a specialized ventilation weaning unit

Background: Weaning from invasive mechanical ventilation (IMV) in specialized weaning units has been demonstrated to be safe and cost‐effective. Success rates and outcomes vary widely, probably relating to patient factors and unit expertise. Methods: An audit was undertaken of patients admitted for weaning from IMV at the Austin Hospital Ventilation Weaning Unit (VWU) between March 2002 and January 2008. Weaning success, complications and both in‐hospital and long‐term mortality were examined and regression analysis was undertaken to examine factors related to these outcomes. Results: Seventy‐eight patients were admitted to the VWU after a median of 27 days of IMV at their referring centre. Weaning success rate (ventilator free or nocturnal non‐invasive ventilation only) was 78.2% (n = 61). Inpatient mortality was 10.2% (n = 8) and serious complications were infrequent. Progressive neuromuscular disease (odds ratio 0.10) and sepsis during admission to the VWU (odds ratio 0.09) were predictive of weaning failure at discharge. Overall survival at 12 months following discharge from the VWU was 66.7% (n = 52) with most survivors residing in the community. Increasing age (hazard ratio 1.93), referral from rural or outer metropolitan centres (hazard ratio 3.57 and 2.37 respectively) and a diagnosis of chronic obstructive pulmonary disease were associated with increased long‐term mortality. Conclusion: High rates of weaning success with infrequent complications and low mortality were achieved in this specialized non‐intensive care unit‐based weaning unit. The VWU may provide a useful template for the development of similar units elsewhere.     

Chromosomal localization of the human urokinase plasminogen activator receptor and plasminogen activator inhibitor type-2 genes: Implications in colorectal cancer

Abstract Activation of the proenzyme of urokinase (uPA) on the surface of cancer cells has been implicated in the initiation of focal proteolytic mechanisms that permit invasion and metastasis by colon cancers. The activity of uPA on the cell surface appears to be a function of the number of uPA-specific receptors (uPAR) and the extent of inhibition of uPA by plasminogen activator inhibitors (PAI). The mapping of the genes coding for uPAR, and for PAI-2, was performed to determine whether their chromosomal localization suggested their involvement in the genetic alterations associated with cancer cell DNA.
This study confirms the localization of the human urokinase plasminogen activator receptor gene to chromosome 19q and, using in situ hybridization, provides a precise localization to chromosome 19q13.2. In addition, our results confirm the previous allocation of the human plasminogen activator inhibitor-2 gene to a location 18q21.3 → 18q21.1, a location that corresponds to the commonest (>70%) somatic deletions found in colorectal carcinomas. The mapping of the uPAR and PAI-2 genes enables the elucidation of their possible involvement in the genetic alterations that determine the invasive and metastatic phenotypes in colorectal cancer.