Peripheral nerve repair by means of a flexible biodegradable glass fibre wrap: a comparison with microsurgical epineurial repair.

In this study, a new technique for the repair of divided peripheral nerves using a flexible controlled-release glass wrap is described and its successful use is reported. Corglaes is a biodegradable and biocompatible glass which, when used as a solid glass tube form as a nerve conduit, allows nerve regeneration. It is now produced as a flexible, porous wrap (CRG-wrap). In this study, the CRG-wrap was used to repair divided median nerves in the upper forelimb of sheep. The wrap was secured in place around the divided nerve ends using fibrin glue or 6/0 polyglactin sutures. Microsurgical epineurial suturing was used to repair the same injury in another group. Twelve sheep were used in each group. A control group of sheep, on which no operations had been carried out, was also examined. The outcome of each repair was assessed at 7 months by measuring transcutaneous stimulated jitter (TSJ), maximum conduction velocity (CVmax), wet muscle mass and morphometric measurements. Testing was carried out on the limb that had been operated upon and the normal contralateral forelimb. The ratio of the measurements taken in the operated and the normal limb (the right and left forelimbs in the control group) was used when carrying out statistical analyses on the results. The mean and variance of the ratios of each of the measured variables in the three repair groups were similar suggesting that nerve regeneration had occurred to a similar degree in all the repair groups (analyses were carried out using one-way ANOVA and Scheffé's test, with statistical significance assumed at p<0.05). The repair of peripheral nerves using the CRG-wrap is easy to learn, quicker and cheaper than microsurgical epineurial suturing, and can be carried out by any surgeon with basic surgical skills. It was concluded that CRG-wrap is a useful alternative to microsurgical epineurial suturing for the repair of peripheral nerves.     

The cloning and sequencing of thealcB gene,coding for alcohol dehydrogenase II,inAspergillus nidulans

Alcohol dehydrogenase II (ADH II, structural genealcB) was purified from a strain H1035,biA1; alcE1; alc500 alcD1, which produces 100-times more ADH II activity than thealcAalcR deletion strain (alc500). Antibodies were raised against this ADH, and were used to screen a cDNA library in gt11. We have isolated the gene for an ADH which is over-expressed in H1035, and which we believe to be thealcB gene; cDNA and genomic clones were sequenced. The sequence contains three introns and encodes a protein of 367 amino acids. This protein shows a clear level of identity to a range of alcohol dehydrogenases, but is no more closely related to the ADH I and ADH III previously described inA. nidulans than to the ADHs ofS. pombe andS. cerevisiae. The significance of consensus sequences found in the 5 region of the gene is discussed in relation to the regulation of the gene.     

Chromosomal mapping and gene disruption of the ADHIII gene in Aspergillus nidulans

Summary There are at least three alcohol dehydrogenases in Aspergillus nidulans. ADHIII has no obvious physiological function. We describe here the cloning of the ADHIII gene (alcC), its mapping on linkage group VII by reverse genetics, and the properties of multicopy transformants tested for their ability to grow on a range of alcohols (butan-1-ol being the best substrate tested for growth). We were unable to detect any obvious alteration in phenotype of a strain carrying a disrupted copy of the ADHIII gene.     

Chromosomal mapping of an alcC disruption with respect to amdA in Aspergillus nidulans

Summary We report the use of the riboB gene for a gene replacement in the alcC gene of Aspergillus nidulans, and show by reverse genetics that the alcC gene is very closely linked to the amdA gene.     

Pathogenesis of idiopathic IgA nephropathy

Despite a prodigious amount of work on the physiology of IgA production in man, and many studies on the immunopathology of IgA nephropathy, ranging from the immunogenetics to the immune response to chemical characteristics of the IgA, we are hardly any nearer to defining the pathogenesis of this disease. One of the main changes in our understanding has been to recognise that the bone marrow, now known to produce normally one-third of the body's IgA, overproduces this immunoglobulin in IgA nephropathy. This alters the previous notion that IgA nephropathy was due simply to IgA production in the mucosa, although a mucosal component is not excluded. Certain characteristics of the IgA in the diseased kidney and the circulation have been defined: it is of subclass IgA1 and has a higher proportion of light chains and negative charge than in normal subjects. The specificities of the IgA, either in the kidney or in complexes, have not helped to clarify the pathogenesis. They have been found for a wide range of endogenous and exogenous antigens, suggesting that the antibody activity represents polyclonal B cell activation. These findings have not helped to confirm the prevailing theory that IgA nephropathy is an immune complex disease. Other theories put forward are that IgA nephropathy is an autoimmune disease, glomerular components or IgA itself being among the candidate antigens, or that there is primary dysregulation of the IgA immune system. At this stage of development in our understanding of this common nephropathy, it is important to guard against the assumption that idiopathic IgA nephropathy is one disease and is the result of a single pathogenetic mechanism.     

Does salivary gland scintigraphy predict response to pilocarpine in patients with post-radiotherapy xerostomia?

This study was undertaken to determine whether standard salivary gland scintigraphy may be used for the objective assessment of salivary gland sialogogues, in particular oral pilocarpine, in the treatment of post-radiotherapy xerostomia. Nine patients, with xerostomia following radiotherapy to the head and neck region underwent salivary gland scintigraphy with technetium-99m pertechnetate (40 MBq) both before and following 1 month of oral pilocarpine (5 mg tds). For each scan, the percentage uptake in the first 14 min, the peak uptake, time to peak uptake and the percentage of activity excreted following lemon juice stimulation were calculated. The results were correlated with the subjective response as assessed by questionnaire and visual analogue scale. We found no correlation between subjective response and any of the four scan parameters analysed. We could not identify any parameter that predicted those patients who would respond to pilocarpine. In addition, only one parameter, the percentage of activity excreted following stimulation, correlated with previous dose of radiotherapy to the gland. In conclusion, in this study salivary gland scintigraphy did not appear to correlate with or predict response to oral pilocarpine. However, future studies might consider performing salivary gland scintigraphy prior to radiotherapy as well as at differing time points following the commencement of pilocarpine.     

An assessment of a computerized reporting system (SIREP)

An assessment is presented of the prototype of a computerized radiological reporting system (SIREP). The system is operated by a radiologist who signals to a computer by touching a glass surface on to which is projected the image of one of 165 slides, each containing words and phrases relevant to the radiographs to be reported. The report is shown on a television screen and is typed automatically when completed. The system was installed in the X-ray Department serving the Accident and Emergency Service of the Bristol Royal Infirmary after a study had been made of the reporting sequences and times using conventional methods. This showed that the major factor influencing the time taken to report a film was whether it was "normal" or "abnormal". The assessment of system looked at its effect on reporting and on the department; its technical aspects and reliability; and its acceptability to radiologists. It was found that because there is no storage or analysis of reports the system directly affected only the radiologist and the secretary. For an average of 100 reports daily it is calculated that a secretary would be saved 64 minutes of typing daily, and that a radiologist would take 63 minutes longer over reporting. In general the system was mechanically reliable and fast in operation, with a maximum slide transit time of three seconds. All radiologists using the machine found that the reporting terminal was simple to operate, but found that reporting abnormalities caused an increased effort and took a longer time. None of the radiologists would use the machine in preference to traditional methods, and in this country no cost or time benefit could be established.