The subcellular basis of damage to the human urinary bladder induced by irradiation

The effects of x-irradiation on the subcellular structure of the human urinary bladder were investigated by electron microscopic examination of biopsies taken during check cystoscopies from 25 patients between 1 month and 22 years after completion of a course of therapeutic radiation. All tissues of the bladder wall were damaged to some extent by the treatment. In the urothelium this was reflected by the development of more than the usual numbers of lysosomes and autophagic vacuoles in all cell layers. In the bladder wall, large often binucleate or multinucleate fibroblasts were prominent and persistent in all specimens and were associated with the development of progressive fibrosis. The vasculature and the muscle coats of the bladder wall were also damaged. In the blood vessels many endothelial cells were oedematous or necrotic and some intravascular coagulation was also observed. Smooth muscle cells became oedematous soon after irradiation, and after longer time intervals there was focal death and loss of individual muscle cells. The observed degeneration and extensive necrosis of the bladder wall, which involved severe destruction and disorganization of the muscular layers, is sufficient to explain the clinical sequelae of bladder irradiation, namely loss of elasticity, reduced capacity and incomplete micturition with residual urine.

Oral rehydration fluids used in the treatment of diarrhoea. Analysis of the osmolalities, and sodium, potassium and sugar contents of commercial and home-made products

Analysis of 91 commercial dietary "clear" fluids, including carbonated beverages, cordials, powdered drinks, jellies, fruit juices, fruit juice drinks, syrups, and soups showed a range of zero to 175 mmol/L of sodium, zero to 52.1 mmol/L of potassium, zero to 839 mmol/L of reducing sugars and an osmolality of 50 to 914 mmol/kg water. Home-made oral rehydration solutions prepared by a group of mothers and medical staff members also showed unacceptably wide variability in their composition. The composition of products specifically indicated for the treatment of diarrhoea was also remarkably diverse, with a range of 24 to 100 mmol/L of sodium, 14.2 to 21.0 mmol/L of potassium, 45 to 326 mmol/L of glucose, and 170 to 460 mmol/kg water osmolality. On the basis of our current knowledge of water and electrolyte absorption, neither the commercial dietary "clear" fluids nor the home-made solutions can be recommended for the treatment of diarrhoea. Of the therapeutic products, only "Unicef Oral Rehydration Salts" has been subjected to clinical trails and found safe and effective. However, the formulation of Diolyte appears appropriate for the treatment of mild diarrhoeal dehydration.

Evaluation of the role of computed tomography in radiotherapy treatment planning

The role of computed tomography (CT) in radiotherapy treatment planning was assessed in a series of 231 patients in whom treatment was planned with radical intent. For each patient, a treatment plan was produced by the best conventional techniques in use at the Middlesex Hospital. Each patient then underwent a CT scan in which the treatment conditions were closely simulated. As a result of the CT scan images, alteration was made to the planned treatment in 47% of 198 assessable patients. Large differences were seen in the usefulness of CT treatment planning for tumours in different sites, with the greatest contribution made to treatment of tumours of the sinuses and nasopharynx and of the bladder. Although its unit cost is high, computed tomography can be a very useful tool in radiotherapy treatment planning and can contribute uniquely to improved patient management for adequately selected patients.

Examination of vocal fold movement by ultra-short pulse X radiography

Antero-posterior radiographs of the larynx lack spatial and temporal resolution, due to the movement of the vocal folds during phonation. By utilising the electrolaryngograph to monitor vocal fold movement, single X-ray pulses of 30 nanoseconds duration have been triggered at pre-determined points during the cycle of vocal fold movement to visualise these in normal phonation.

Studies on enterotoxigenic Escherichia coli isolated from persons without diarrhoea in Western Australia

The epidemiology of enterotoxigenic Escherichia coli (ETEC) was studied in children without diarrhoea in two remote Aboriginal communities in tropical north-western Australia. Serial surveys of the same individuals during different seasons showed that isolations were much more frequent in the wet monsoonal summer than in the dry winter. All E. coli were isolated from symptomless children aged 5 years or less; in addition, clearance of ETEC carriage without treatment was observed in all individuals within 3 months of isolation. Of the 58 ETEC strains isolated, 40 had either an H32 or an O126 antigen. Five O antigens which have never been associated with ETEC (O2, O41, O71, O77 and O157) were found. A recently proposed system to detect ETEC, using groups of polyvalent antisera, would have detected only 3 out of these 58 ETEC strains.

A modified infant mouse assay for bacterial enterotoxins

The reproducibility of the infant mouse assay for Escherichia coli ST and heat-labile enterotoxins of Aeromonas spp. is improved if both intestinal weight to remaining body weight ratio (IW/RBW) and the amount of diarrhoea produced are considered as criteria for classifying enterotoxigenic strains. Animals with profuse diarrhoea may have IW/RBW ratios below the widely accepted critical value for a positive test. Using pools of supernatants from broth cultures of three different strains of E. coli, 15% of ST producers would have been regarded as negative using IW/RBW ratio as the only criterion of a positive test. In testing single supernatants, 25% of ST producing E. coli would not have been correctly classified using IW/RBW alone. A scoring system which incorporates IW/RBW ratios and the amount of diarrhoea produced improves the usefulness of the test by allowing clear separation of positive and negative strains. The scoring system is also applicable to older mice for assay of E. coli ST so that a wider age range of mice can be used allowing increased use of animal facilities.

Long-term organ culture of normal human bladder

Normal adult human bladder obtained at cystoscopy has been maintained in long-term organ culture. Several media were tested for their ability to maintain viability and normal tissue morphology. The optimum medium was Ham's F-12 nutrient mixture, supplemented with 10% fetal calf serum, hydrocortisone (1 microgram/ml), and FeSO4, (0.45 microgram/ml). During the first 28 days in vitro, epithelial damage incurred at biopsy and during preparation of the cultures was repaired, and epithelialization of cut stromal surfaces occurred. A wave of cell proliferation was identified by [3H]thymidine autoradiography, 24-h labeling indices rising to a peak of up to 50% on the cut sides of the cultures between 7 and 21 days and falling to 0 to 5% by 21 to 28 days. The regenerating epithelium showed all the normal features of urothelial cell differentiation when examined by scanning and transmission electron microscopy. From 28 days, histology and scanning and transmission electron microscopy showed the cultured urothelium in most cultures to resemble closely that in the normal bladder in vivo, and in this mature state cultures were maintained for 100 days. Urothelium derived from certain patients, although showing normal surface maturation, developed enlarged intercellular spaces or intraepithelial mucin-containing acini. A study of the cytology of cells shed into the medium at different stages in culture showed that culture viability and epithelial differentiation could be monitored easily in long-term culture by this nondestructive means.

Early and late morphological changes (including carcinoma of the urothelium) induced by irradiation of the rat urinary bladder

Effects of X-irradiating the urinary bladder of female F344 rats with a single dose of 20 Gy were studied by light and electron microscopy. The animals were killed 1 week-20 months post-irradiation, and all tissues of the bladder wall were found to be affected by the irradiation. In the urothelium, damage was initially restricted to the basal cells but slowly extended to intermediate cells, and by 6 months post-irradiation the urothelium was focally hyperplastic. Twenty months post-irradiation, transitional-cell carcinomas were found in 10 of the surviving 17 animals (59%). The blood vessels in the bladder wall showed damage to both the endothelial cells and the smooth muscle. The fibroblasts in the connective tissue of the bladder wall appeared to show increased secretion after irradiation, and there was abundant collagen deposition, resulting in severe fibrosis of the bladder wall. After a latent period of a few months, focal degeneration and extensive necrosis of the smooth muscle cells were seen, leading to severe destruction and disorganization of the muscular coats of the bladder wall. Thus, a single dose of irradiation of 20 Gy was sufficient to produce severe fibrosis of the bladder wall with smooth muscle degeneration and to induce carcinoma of the urothelium in most of the treated animals within 20 months.

Seventh interim progress report of the british institute of radiology fractionation study of 3F/week versus 5F/week in radiotherapy of the laryngo-pharynx

A fresh analysis of the data entered into the multicentre BIR fractionation trial of 3F/week versus 5F/week in radiotherapy of the laryngopharynx has been undertaken. Completed records of the 732 patients initially entered into the trial have now risen from 687 at the last report to 706. The data have been analysed in a manner similar to that adopted previously so as to measure the effects of the two regimes on both tumour and normal tissues, and some additional analyses have now also been made. There have been some modifications in the results in the various sub-groups which may be due to an inadequate number of patients having been followed up for long enough at the time of the previous analyses. More data for late radiation damage to normal tissues and new radiobiological findings have suggested possible explanations for the differences which have emerged between the two groups. The apparent differences between the sub-groups containing patients with highly localized tumours, which were reported in our previous report, are now less marked and not statistically significant.

Exotoxins of Aeromonas hydrophila

Eighty of 103 strains of Aeromonas hydrophila cultured at 100 rev./min produced heat-labile enterotoxins detected using the suckling mouse assay. Results in intestinal perfusion agreed with the suckling mouse test in all strains tested by both methods. Enterotoxic activity correlated with haemolysin and cytotoxin production, but 4% of strains would have been wrongly classified using haemolysin assay in place of the suckling mouse test and 11% misclassified on the basis of cytotoxin assay. There was a significant association between haemolytic and cytotoxic activity, but 15% of strains produced only one of these toxins. Haemolysin, cytotoxin and enterotoxin were not always associated in a given isolate. The time of appearance of exotoxins during bacterial growth and the effects of dialysis, heating and proteolytic enzymes also suggest that haemolysins, cytotoxins and enterotoxins of Aeromonas hydrophila are separate toxins and not different manifestations of the same toxin.

Detection of enterotoxins of Aeromonas hydrophila by a suckling-mouse test

The suckling-mouse assay was reliable for detecting enterotoxigenic strains of Aeromonas hydrophila when standard conditions for growth and toxin testing were used. Enterotoxins were produced by bacteria grown in tryptone soya broth supplemented with yeast extract and aerated by shaking in an environmental incubator or water bath. When culture supernates together with dye were administered intragastrically to mice less than 6 days old, the presence of enterotoxin was assessed on the basis of a scoring system that incorporated the ratio intestinal weight: remaining body weight, and production of diarrhoea. This method should facilitate the detection of enterotoxigenic strains of Aeromonas in epidemiological studies.

Xeroradiographic tomography of the larynx

Adequate assessment of disease extent is vital for tumour control in the larynx. Xeroradiography using a tomographic technique was investigated. A preliminary study was carried out to assess the optimum technique and exposure. It was also found that the radiation dose to the skin, although just over twice that for film, could be halved by the removal of the secondary radiation grid. Images of 24 patients treated were assessed for soft tissue and bony detail, and it was found that the xerotomograms were beneficial to the radiotherapy planning of the treatment volume of laryngeal and related neck carcinomas.

A semilethal t-haplotype in the Orkney Islands

Breeding tests of wild house mice, trapped from an isolated population from Sanday in the Orkney Islands, have demonstrated the presence of a semilethal t-haplotype designated tw106. Microscopic examination of sperm and testes from a sterile male obtained from this population revealed the histological characteristics typical for homozygotes for semilethal t-haplotypes. This report is the first description of the recovery of a t-haplotype from an island population of wild mice.

Diarrhoeal disease in Aboriginal and non-Aboriginal infants and young children in Western Australia

There were remarkable differences in the rates of admission to hospital for gastroenteritis of Aboriginal and non-Aboriginal infants and children in Western Australia during the eight-year period, 1971 to 1978. Although Aborigines made up only 3.7% of the State's population under five years in 1976 (the last census year) they accounted for 42% of admissions to hospital for gastroenteritis and had 58% of the bed occupancy for that disease. The highest rates of admissions were for rural infants, whether they were Aboriginal or not. Other infections, particularly of the respiratory tract, were other common causes of admission to hospital. There has been a very encouraging decline in deaths from diarrhoeal diseases, particularly in young Aborigines, in the period reviewed. Hospital admission rates also decreased for Aborigines during the latter half of the study, with the largest fall occurring in metropolitan infants, but there is still a very wide gap between the rates experienced by the Aboriginal and non-Aboriginal population under five years of age.

Transient radiation myelopathy: spinal somatosensory evoked responses following incidental cord exposure during radiotherapy

Serial spinal somatosensory evoked potentials were recorded in six patients undergoing radiotherapy involving incidental spinal radiation. Two patients developed transient radiation myelopathy. No abnormality was found in the somatosensory evoked potentials throughout the study.