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Biomedical subjects

J M Heaton

Publications and source records attributed to J M Heaton.

At least 19 recordsLinked to original sources

Factors associated with positive bacteriological cultures of chronic middle ear effusions.

Pathogenic bacteria have been isolated from middle ear effusions in a number of studies. Our aim was to identify factors which predispose to patients having positive cultures. Over a 1-year period, prospective data were collected on patients admitted for myringotomy. Middle ear effusions were collected at the time of surgery using specially designed traps, and underwent microscopy and culture. Data on local weather parameters were obtained from the Meteorological Office in Edinburgh, UK and compared with the patterns of positive cultures. A higher proportion of cultures were positive in October, November and December and in February and May than in the other months of the years. We were not able to relate these variations to any of the meteorological data, with the possible exception of relative humidity, or to any other variable.

Adolescent

A comparison of performance of Shepard and Sheehy collar button ventilation tubes.

This study was designed to confirm the longer in situ life of the Sheehy collar button compared with the Shepard tube and to assess the complication rates associated with the two tubes. Cases of bilateral otitis media with effusion had a Shepard tube inserted in one ear and a Sheehy contralaterally. The insertion position was allocated randomly. The patients were then assessed at three-monthly intervals for two years. In 71 per cent of those in whom at least one tube had extruded, the Sheehy remained in situ longer. The antero-inferior tube remained longer than the postero-inferior whichever type was used. There was no significant difference between complication rates, or recurrence rates of middle ear effusion after tube extrusion, for the two types. We conclude that use of a Sheehy rather than a Shepard tube carries no increased risk of complications and the patient may require further surgery less often in total.

Adolescent

An assessment of the incidence of iron deficiency in paediatric otolaryngology inpatients.

The aims of this study were: to determine whether there is an increased incidence of iron deficiency in paediatric otolaryngology inpatients compared with other surgical controls; and to establish whether preoperative screening of haemoglobin level is warranted in such patients. Children aged 1-10 years admitted electively for ENT surgery or for general surgical procedures had blood taken for haemoglobin level, mean cell volume and serum ferritin. Their age, weight, socioeconomic class and ethnic background were recorded. A total of 100 patients entered the study, in a six-month period. The mean ages and weights for the two groups were statistically different, so allowance was made for this in calculations. Social class was not significantly different. No relationship could be established between haemoglobin level and ferritin level for individual patients. Multiple regression analysis for haemoglobin level, mean cell volume and for ferritin level showed that allowing for the age and weight differences these variables were not significantly different for the two groups. This study has therefore shown no increased incidence of iron deficiency in paediatric ENT inpatients. Each Department should formulate its own policy on pre-operative haemoglobin screening, based on local considerations.

Child

Waiting list initiatives: crisis management or targeting of resources?

To investigate the impact of a waiting list initiative on an ENT surgical waiting list, we have evaluated the outcome of the Tayside ENT Waiting List Initiative. Four hundred and forty-five patients were offered dates to come in during the initiative. Of these, 280 underwent surgery and 16 indicated that their operations were no longer necessary. The maximum wait for routine operations falling within the criteria for inclusion in the initiative was 28 months prior to the initiative can be effective in reducing waiting times for routine surgery. However, it is too early to describe the Tayside initiative as an unqualified success, as it remains to be seen whether or not the waiting list will lengthen again now that it is over.

Humans

Penicillium aurantiogriseum-induced, persistent renal histopathological changes in rats; an experimental model for Balkan endemic nephropathy competitive with ochratoxin A.

Renal histopathological changes in rats, caused by food partially moulded by a common fungus isolated from an area of nephropathy in Yugoslavia, were differentiated into acute and chronic responses. The acute response to a few days on the diet specifically involved necrosis and concomitant mitosis in proximal tubule cells. More protracted, continuous or intermittent administration of nephrotoxic mould led to a marked karyomegaly in the same corticomedullary region. The phenomenon is more prominent than that induced by treatment with ochratoxin A over a similar period, raising the question of the putative role of such mycotoxins in the etiology of chronic human renal disease.

Acute Disease

Acute histopathological changes produced by Penicillium aurantiogriseum nephrotoxin in the rat.

Shredded wheat moulded by an isolate of Penicillium aurantiogriseum elicited progressive histopathological changes at the rat renal cortico-medullary junction during 5 days of dosing, when incorporated into diet as a 20% component. The changes of acute tubular necrosis and regeneration were seen in the P3 segment of the nephron. In rats exposed to contaminated diet for 5 days the histopathological changes regressed in severity by about one-half within a further 4 days on normal diet and by 7 days the tubular epithelium was nearly normal. A partially purified fraction of an alcohol extract, selected by preparative high-voltage electrophoresis and anion exchange and notably rich in amino-compounds, was typically nephrotoxic when given in diet over 4 days. Acute marked tubular necrosis also occurred when the same fraction was given intraperitoneally over a similar period. The acute histological changes provide a rapid bioassay for this Penicillium nephrotoxicity and facilitate the search for the toxic metabolite(s). The cumulative expression of necrosis and repair over only a few days in tubular epithelium suggests that chronic exposure will elicit a more complex pathology which might serve as an experimental model for the idiopathic Balkan endemic nephropathy.

Animals

Tumefactive fibroinflammatory lesions of the head and neck.

The term 'tumefactive fibroinflammatory lesion' has been used to describe a fibrosclerosing disorder which has a locally destructive nature but is characterized by a benign histological appearance. We report five patients, over a five year period, with such a lesion. The clinical behaviour and surgical findings suggest the lesion to be an invasive malignancy. However, the histological appearance of an admixture of chronic inflammatory cells and fibrosis is consistent with a benign condition. We recommend surgical excision of the lesion as the mainstay of treatment; other studies report the use of steroids and radiotherapy.

Adult

Thoracic outlet compression syndrome: the lack of reliability of its clinical assessment.

Four manoeuvres advocated for the assessment of thoracic outlet compression were performed on 64 randomly chosen volunteers. Although only 17% had any symptoms of thoracic outlet compression, 58% had a positive result in at least one of the manoeuvres. Only 2% were positive for more than two manoeuvres. We suggest this low specificity devalues these tests in clinical practice. We were unable to correlate our clinical results with the findings of digital photoplethysmography.

Adolescent

Vasitis nodosa--a site of arrest of malignant germ cells.

A 40-year-old man, with a history of vasectomy 11 years previously, presented with a tumour in his right testis. At orchidectomy a seminoma was found, together with a nodule on the vas deferens. Histological examination of this area in the vas identified the lesion of vasitis nodosa and also showed it to be the site of proliferating germ cells. The pathogenesis of this lesion is discussed.

Adult

Persistent renal damage following pre-eclampsia: a renal biopsy study of 13 patients.

Renal biopsy material was examined from 13 patients who had a history of pre-eclampsia and who were biopsied after delivery. The characteristic 'endotheliosis' associated with pre-eclampsia appeared to resolve at varying rates and was not seen in biopsies taken more than 1 month after delivery. Four of the biopsies showed residual focal segmental glomerular lesions which are described. Focal global glomerular sclerosis (eight biopsies), focal interstitial scarring (seven biopsies) and arteriolo-sclerosis (nine biopsies) were also identified. These findings support those earlier reports which indicated that pre-eclampsia is capable of producing persistent renal damage in a small but significant percentage of cases.

Adolescent

Reflections on notochordal differentiation arising from a study of chordomas.

This study of thirteen cases of chordoma serves to emphasize the occurrence of three different histological patterns; classical, seven; chondroid, three; and intermediate or mesenchymal, three. The study also suggests that more adequate sampling of these tumours detects the chondroid variant more readily. These varying patterns of differentiation in tumours of notochordal origin suggest that the parent tissue may have the potential to develop along similar lines in the embryo. Thus mesenchymal and cartilaginous tissue formed from notochordal cells could contribute to the formation of the nucleus pulposus and inner portion of the intervertebral disc cartilages. This concept contrasts with the previously held view that the notochord atrophies at an early stage in embryonic development.

Adult

An evaluation of the immunoperoxidase technique in renal biopsy diagnosis.

An evaluation of the use of horseradish peroxidase labelled antisera against IgG, IgM, IgA and C3 compared with corresponding antisera labelled with fluorescein isothiocyanate has been carried out on renal biopsy material from 200 patients with renal disease. A disparity between the two methods was observed in 10-19% of the readings according to the antigen being demonstrated. The majority of differences recorded would not have influenced the executive diagnosis. Where the immunological results could have influenced the executive diagnosis, 5 probable false results were obtained using innumofluorescence and 4 with immunoperoxidase. Immunoperoxidase has the advantage over immunofluorescence in that it provides a permanent preparation which can be reviewed months or years later. In addition it provides more accurate localization of the immune deposits since the section can be counterstained with Mayer's hemalum and viewed by conventional light microscopy. In view of these advantages we recommend that serious consideration should be given to using immunoperoxidase in place of immunofluorescence for the examination of renal biopsy material.

Biopsy

Prognosis of Henoch-Schönlein nephritis in children.

All the survivors of a series of 88 patients with Henoch-Schönlein nephritis were examined after a follow-up of six and a half to 21 years (mean 9-9). Sixty-one patients had no demonstrable abnormality; six had minor urinary abnormalities; five had hypertension without urinary abnormally or renal dysfunction; four had heavy proteinuria; eight were in chronic renal failure, three of whom were on regular dialysis; and four patients had died within 25 months of onset. Neither corticosteroids nor immunosuppressive drugs alone or in combination appeared to influence the outcome. A clinical presentation with a combination of acute nephritis and a nephrotic syndrome and a high proportion of crescents in renal biopsy specimens was associated with a poor outcome. Neither the clinical presentation nor the renal morphology were, however, precise determinants of outcome. Outcome was not related to age, associated streptococcal infection, or recurrences of the rash. The clinical state two years after presentation was compared with the state six and a half years or more after presentation in 76 patients. The clinical state had changed in 32 patients, in 17 of whom it had deteriorated. It was not possible to identify with any certainty the patients who would deteriorate (or improve). Patients who have had Henoch-Schönlein nephritis should be followed up for at least five years.

Adolescent

Localization of glomerular "deposits" in Henoch--Schönlein nephritis.

Twenty-five renal biopsies from patients with Henoch--Schönlein nephritis were examined using light microscopy, immunofluorescence, 1 micrometer plastic-embedded sections and electron microscopy. The 1 micrometer plastic-embedded sections and electron microscopy showed deposits in mesangial, subendothelial and subepithelial sites. Some of the latter were very large and similar to those which have been described as "humps" in acute proliferative glomerulonephritis. Immunofluorescence showed the mesangial deposition of IgG, IgA and C3 with extension into a peripheral position in some cases. Fibrin was frequently found associated with crescents. The case for Henoch--Schönlein disease being mediated, in part at least, by immune complex deposition, is presented.

Complement System Proteins

Papillary necrosis associated with calyceal arteritis.

The renal papilla has a double blood supply - from both the vasa recta and the calyceal arteries. The importance of the latter supply is not established. A case of polyarteritis associated with papillary necrosis is reported, in which the calyceal vessels, supplying the area, show acute necrotizing arteritis and occlusion. The pathophysiological and clinical implications are discussed.

Drug Hypersensitivity

Extrarenal malignancy and the nephrotic syndrome.

The clinical and histological findings are described of a patient who presented with the nephrotic syndrome and was found at necropsy to have a bronchial carcinoma. Amyloidosis, renal vein thrombosis, and neoplastic infiltration of the kidneys were excluded. The kidneys showed a diffuse glomerulonephritis of mesangiocapillary type. The possible aetiological association between these two conditions is discussed.

Bronchial Neoplasms