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Biomedical subjects

I McColl

Publications and source records attributed to I McColl.

At least 19 recordsLinked to original sources
PubMed1992

Motor nerve biopsy in severe Guillain-Barré syndrome.

We undertook a biopsy of a terminal branch of the musculocutaneous nerve in a man with severe Guillain-Barré syndrome and very small distally evoked action potentials. The biopsy showed pronounced subperineurial edema, macrophage infiltration, and many axons that had been completely demyelinated, some associated with intratubal macrophages. The biopsy unequivocally identified the pathological process as primary demyelination, not axonal degeneration, and was more informative than previous reports of sural nerve biopsies in patients with Guillain-Barré syndrome.

Axons↗
PubMed1992

Success rates for rehabilitation of vascular amputees: implications for preoperative assessment and amputation level.

All lower limb amputations performed during 1986 and 1988 in eight hospitals in the south-east region were assessed. Of 440 amputations for vascular disease, 193 were above-knee, 193 below-knee, 15 Gritti-Stokes, 15 through-knee and 24 bilateral. Of the 440 patients, 75 died in hospital, 113 were considered unsuitable for a prosthesis and 252 (57 per cent) were referred for prostheses. Rehabilitation questionnaires were sent to 179 patients (41 per cent), as a further 54 had died and 19 had become known non-wearers before the study commenced. The response rate was 81 per cent; 102 patients completed the questionnaire, 21 were reported dead, and 22 were non-wearers. Of a maximum rehabilitation score of 12, 52 patients scored 6 or more (consistent with mobility on their artificial limb around the home), and 21 scored 9 or more (a standard accepted as successful rehabilitation). It is concluded that 10-15 per cent of amputees achieve mobility around the home on their prosthesis. Only 5 per cent, however, rehabilitate well and become independent of their wheelchair. When amputation is inevitable, more consideration should be given to surgery that optimizes wheelchair rehabilitation.

Aged↗
PubMed1992

Regulation of major histocompatibility complex (MHC) products in fresh and cultured human fetal pancreata aged 9-16 gestational weeks by gamma-interferon.

Immunological data on the human fetal pancreas (HFP) are mainly confined to its constitutive expression of the MHC antigens. However, cytokines, such as gamma-interferon (g-IFN), released by lymphocytes during immune reactions, can induce or upregulate the expression of MHC products in allografts and alter their immunological behaviour. We investigated the effects of g-IFN on fresh and cultured HFPs aged 9-16 gestational weeks (gw). Following g-IFN stimulation of fresh HFPs, there was class I hyperexpression by the ductal cells, and some of the ductal, endothelial and islet cells also became class II+. Conventional tissue culture (5% CO2 in air at 37 degrees C) reduced the number of interstitial class II+ cells within the HFP after 1 week but was associated with de novo class I expression by some of the ductal cells. Remarkably, the changes in major histocompatibility complex (MHC) antigen expression by the ductal cells occurred earlier and were markedly enhanced when the HFPs were cultured beforehand. The number of interstitial class II+ cells in fresh and cultured HFPs was not influenced by g-IFN. The significance of these observations with regard to clinical HFP transplantation is discussed.

Culture Techniques↗
PubMed1991

Palliation of malignant dysphagia with laser therapy: predictability of results.

This study reports the results of 189 patients treated by laser therapy for malignant dysphagia. Ninety-one per cent of patients derived benefit from treatment, but the long-term survival rate was poor, with only 12 per cent of patients surviving for 6 months. Survival was not influenced by either tumour length, site or histological type. Patients with adenocarcinomas initially showed improved swallowing after laser treatment compared with those with squamous tumours, but this difference had disappeared by 2 months. The results of laser treatment were not influenced by either tumour length or site.

Adult↗
PubMed1991

The immunology of the human foetal pancreas aged 8-13 gestational weeks.

The expression of MHC class I and class II antigens by the human foetal pancreas (HFP) during the first trimester is poorly documented. Using immunohistochemical techniques, we analysed 37 HFPs aged 8-13 gestational weeks (gw) and compared the results with those of 9 HFPs aged 14-16 gw. In all of the specimens, the ductal cells were class I- and class II-negative. Islets and endothelial cells expressed class I but were class II-. Interstitial class II+ cells included macrophages, B lymphocytes and dendritic-like cells that were negative for macrophage markers. While the frequency of class II+ cells in the HFP remained constant from 8 to 13 gw, a threefold increase was observed from the end of the 13th gw to the 16th gw. In conclusion, the lower density of interstitial class II+ cells in HFPs aged 8-13 gw indicates that immunomodulation is likely to be more successful in this age group.

Antibodies, Monoclonal↗
PubMed1991

Gastric carcinogenesis in the rat induced by duodenogastric reflux without carcinogens: morphology, mucin histochemistry, polyamine metabolism, and labelling index.

Chronic duodenogastric reflux induces gastric adenocarcinomas in the rat without the use of carcinogens. Altogether, 186 male Wistar rats were randomised to undergo either a simple gastrojejunostomy or a gastrotomy and sacrificed at eight weekly intervals for 56 weeks. No control animals developed dysplasia or carcinoma. All rats subjected to a gastrojejunostomy showed hyperplasia of the proliferative neck zone, with increased sulphomucin production adjacent to the scar. Low grade dysplasia was found at 16 weeks, and carcinoma was first seen at 32 weeks. Most carcinomas were well differentiated mucin secreting adenocarcinomas of the expanding type, which secreted a mixture of sialomucins and sulphomucins. Duodenogastric reflux was associated with a 100% increase in labelling index (assessed autoradiographically with tritiated thymidine) in the gastric mucosa when compared with corresponding tissue adjacent to a gastrotomy scar. This increase was significant at eight weeks and persisted for 56 weeks after surgery. This study supports the theory that, in this model, hyperplasia precedes the development of carcinoma.

Animals↗
PubMed1990

Recurrent phaeochromocytoma.

The recurrence of symptoms and hypertension in a patient who has previously undergone an operation for phaeochromocytoma should alert the physician to the need to investigate for recurrent tumour. Failure to perform complete excision of the adrenal gland containing the tumour may lead to disseminated recurrence.

Adrenal Gland Neoplasms↗
PubMed1989

Recessive mutations and chromosome deletions leading to cancer.

This review examines the effect that a small chromosome deletion affecting a specific DNA sequence may have in producing a state of 'hemizygosity' for a gene or genes, and so triggering malignancy of the cells concerned. The association between such deletions and a variety of cancers will be considered and the implications for clinical practice will be outlined.

Chromosome Aberrations↗
PubMed1989

Rehabilitation after lower limb amputation: a comparative study of above-knee, through-knee and Gritti-Stokes amputations.

A study of 169 unilateral amputees under three Disablement Services Centres was performed. The study comprised 88 above-knee, 54 through-knee and 27 Gritti-Stokes amputations. Satisfactory rehabilitation occurred in 33 per cent of above-knee, 62 per cent of through-knee and 44 per cent of Gritti-Stokes patients (56 per cent overall). The better rehabilitation of through-knee versus above-knee amputees (P less than 0.02) was also found in a group of patients matched for comparable age and duration of amputation as well as in a group of age-matched vascular amputees. Through-knee amputees relied significantly less on wheelchairs than above-knee (P = 0.016) and Gritti-Stokes (P = 0.05) amputees. The prosthesis used for the through-knee and Gritti-Stokes amputations was considered unsightly in 50 per cent of cases (versus 31 per cent for the above-knee prosthesis). The superior rehabilitation with through-knee amputations should prompt us to improve both our technique for this amputation and the prostheses currently available. A through-knee amputation should be performed in preference to an above-knee amputation in the case where either is surgically possible, and a below-knee amputation not feasible.

Adult↗
PubMed1989

Induction of pancreatic tumours by longterm duodenogastric reflux.

The incidence of pancreatic cancer is increased in patients who have undergone gastric surgery. An animal model is described in which pancreatic hyperplasia and adenoma formation developed within 56 weeks. The effects of a simple gastrojejunostomy were compared with those after a split gastrojejunostomy, in which the jejunum was transected and the two limbs implanted separately into the greater curvature of the glandular stomach 1 cm apart. After 56 weeks no animals in the simple gastrojejunostomy group had pancreatic hyperplasia whereas all 10 animals in the split gastrojejunostomy group had generalised pancreatic hyperplasia with macroscopic nodules. Microscopy of the nodules showed that in nine animals hyperplastic nodules had developed, and four of these also had adenomatous nodules. The remaining animal had enlarged lymph nodes. Pancreatic hyperplasia was associated with jejunal hyperplasia. Jejunal morphometry showed that the villus height was doubled and the villus height:crypt depth ratio was higher in the split gastrojejunostomy group compared with those animals with a simple gastrojejunostomy. This finding represents a new model for the investigation of pancreatic neoplastic change.

Adenoma↗
PubMed1989

Dukes A carcinoma after colonic interposition for oesophageal stricture.

The management of caustic and peptic oesophageal strictures refractory to medical treatment and repeated dilatations continues to be a challenge. Colonic interposition with subtotal oesophagectomy is felt by many surgeons to be the best treatment. Complications in the short and long term are, however, frequent. We report a case of a colonic carcinoma originating in a colonic interposition and growing up into the oesophageal remnant.

Adenocarcinoma↗
PubMed1988

Pancreaticoduodenal secretions and the genesis of gastric stump carcinoma in the rat.

This study was designed to investigate the role of duodenogastric reflux in the genesis of gastric stump carcinoma in the rat. Carcinoma was not detected in any of the 11 control animals and in only one animal with a Roux diversion. In contrast seven of 12 animals with duodenogastric reflux developed carcinoma (p less than 0.01 and p less than 0.05 respectively). In order to determine which fraction of the reflux was implicated in the malignant process, animals with reflux of bile alone or pancreaticoduodenal secretions alone were studied. No carcinomas were found in 11 animals with bile reflux alone, but carcinoma was detected in 10 of 14 animals with reflux of pancreaticoduodenal secretions (p less than 0.01). The findings confirm that duodenogastric reflux is an important factor in the malignant process, and imply that the pancreaticoduodenal component, not bile is responsible.

Animals↗
PubMed1987

Biosynthesis of proteins by human gastric mucosa in vitro.

Incorporation of L-[U-14C]leucine and of D[U-14C]glucose into proteins of fresh human gastric mucosa in vitro was studied after incubation of homogenized tissue and of intact mucosal pieces. CsCl centrifugation was used to separate high-density mucus glycoproteins from other mucosal proteins, and the macromolecular nature of radioactive mucosal glycoprotein fractions was confirmed by SDS/polyacrylamide-gel electrophoresis and autoradiography of the polyacrylamide gels. In all experiments a substantial proportion of total incorporated radioactivity was associated with gastric-mucosal glycoprotein fractions (CsCl fraction L3), indicating their biosynthesis. Radioactivity of these fractions was shown to co-chromatograph with carbohydrates when fractionated either directly or after reduction and alkylation (1) Sephadex G-200 chromatography in the excluded fractions and (2) by DEAE-cellulose ion-exchange chromatography. On incubation of intact mucosa, the major portion of radioactivity associated with the glycoprotein fractions of both leucine- and glucose-labelled specimens was secreted into the mucosal media during the course of the experiment. It is suggested that biosynthesis of mucus in vivo by gastric mucosa may be associated with rapid secretion of the synthesized macromolecules into the lumen of the stomach and that investigations of the metabolic processes within the mucosa should consider the products of secretion of the tissue. Incorporation of L-[U-14C]leucine implies biosynthesis of the polypeptide components of the macromolecules.

Autoradiography↗