Virulent and attenuated canine distemper virus infects multiple dog brain cell types in vitro.

Canine Distemper Virus (CDV) produces an encephalitis in dogs that varies with viral strain. We have studied the cell tropisms of two virulent strains (CDV-SH and CDV A75-17) and an attenuated strain, Rockborn (CDV-RO), in cultured canine brain cells. Infected cell types were identified by double immunofluorescent labeling of specific cell markers and viral antigens. All viral strains studied produced infection in astrocytes, fibroblasts, and macrophages. Neurons were not infected by CDV A75-17 but were rapidly infected by CDV-SH and CDV-RO. Multipolar oligodendrocytes were very rarely infected by any of the virus strains. In contrast, a morphologically distinct subset of bipolar oligodendrocytes were commonly infected by CDV-SH and CDV-RO. The kinetics of infection in the astrocytes, oligodendrocytes, neurons, and macrophages varied between strains. Both CDV-SH and CDV-RO rapidly infected bipolar oligodendrocytes, astrocytes, neurons, and macrophages by 14 days post infection while infection by CDV A75-17 was delayed until after 28-35 days post infection. The differences in the growth kinetics and cell tropisms for some brain cells, exhibited by the three viral strains examined in this in vitro study, may relate to the different CNS symptoms that these strains produce in vivo.     

Hypospadias repair without a bladder drainage catheter

We report on 44 consecutive patients who underwent 1-stage hypospadias repair based on a urethral splent (silicone pleated stent). The severity of hypospadias ranged from subcoronal in 12 cases and distal in 23 to midshaft in 4 and penoscrotal in 5. In the first 15 patients of this series the splent was used with a suprapubic tube. All patients were able to void within the first 36 hours postoperatively. The next 29 patients underwent repairs without the use of a bladder catheter, including 15 who had outpatient procedures. None of the 44 patients has required subsequent catheterization or hospitalization. There have been 2 fistulas in this series. The urethral splent permits normal voiding through and drainage of the neourethra in a variety of hypospadias repairs. The splent expands and contracts with the degree of edema and permits catheterization should this be necessary. The advantages of hypospadias repair without bladder drainage, such as short hospital stay, total ambulation, and decreased potential for infection and bladder spasm, can be realized with the use of a urethral splent.     

Guidelines for the collection, processing and storage of human bone marrow and peripheral stem cells for transplantation

SUMMARY. There are no current U.K. or international guidelines or regulations covering the production, processing and storage of haemopoietic cells such as to allow their engraftment following myeloablative therapy. This paper seeks to provide such guidelines. It enumerates how quality control and assurance can be applied to this area of transfusion medicine; procedural steps relating to bone marrow harvest on peripheral blood stem cell collection are outlined and recommended doses of nucleated cells suggested for both procedures. General specifications for identification, storage and transportation of bone marrow and peripheral blood stem cells are included and specific laboratory procedures related to the provision of haemopoietic cells for engraftment are outlined. Umbilical cord blood transplants and long-term bone marrow culture are alluded to but these are still in a research phase.     

Statistical issues arising from mouse micronucleus assay experiments of Ashby and co-workers.

Data from a series of mouse micronucleus assays have been reanalysed to illustrate various statistical issues raised by Ashby and co-workers during the development of the assay. Most of the statistical points discussed in these earlier papers can be explained by the stochastic nature of the data. Reanalysis shows that the type of data collected in mammalian micronucleus assays is amenable to analysis by standard biometric methods. It is concluded that statistical analysis has an important role in the exploration and interpretation of data from the micronucleus assay.     

Toxicity of the blue-green alga (cyanobacterium) Microcystis aeruginosa in drinking water to growing pigs,as an animal model for human injury and risk assessment

Hepatotoxins from blue-green algae are increasingly recognized as a potential hazard in drinking water supplies. The clinical consequences of ingestion include acute or chronic liver injury, with the possibility of enhanced susceptibility to, and growth of, liver tumors. To establish guidelines for water safety requires the demonstration of dose-dependent effects of toxicity and experimental determination of maximum “no-adverse-effect levels.” This paper describes the use of growing pigs as a model for human injury resulting from Microcystis toxins in drinking water. Risk assessment calculations using a series of safety factors are carried out, resulting in a guideline level after incorporating an additional safety factor for tumor promotion of approximately 1.0 μg toxins/L. With the Microcystis used for this trial, that concentration corresponds to 5000 cells/mL. © 1994 by John Wiley & Sons, Inc..     

Artifacts due to stimulus correlated motion in functional imaging of the brain

To assess the effect of stimulus correlated motion on the appearance of functional magnetic resonance images, conventional visual and motor protocols were each performed by four normal volunteers and an image co-registration technique was used to retrospectively monitor subject motion. In three studies synthetic data sets were constructed from single baseline images using the positional information obtained from the co-registration procedure. Cumulative difference images were then created from both the synthetic and functional image sets. Stimulus correlated motion was detected in all eight studies and the synthetic cumulative difference images showed striking similarities to the equivalent functional images in each case.