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Biomedical subjects

M C Allison

Publications and source records attributed to M C Allison.

At least 37 records · Page 2Linked to original sources

Hepatitis C virus infection detected by antibody tests and the polymerase chain reaction as a cause of liver dysfunction in renal transplant recipients.

Hepatitis C infection (HCV) is more prevalent in patients who have received kidney transplants than in the general population but the morbidity and mortality associated with infection in this group is unclear. Sera taken from 36 renal transplant recipients with chronic liver dysfunction and from 42 with normal liver function were tested for HCV infection by second generation ELISA (Abbott Laboratories) and second generation recombinant immunoblot assay (Chiron Corporation) (RIBA-2). Evidence of HCV replication was sought by reverse transcription polymerase chain reaction (RT PCR) using primers from the 5' nontranslated region (5'NTR). Infection was detected in 20/36 (54%) and in 2/42 (4.8%) controls (P < 0.01). Twelve liver dysfunction patients were positive by all three tests, six were positive by ELISA and RT PCR but had indeterminate RIBA-2, one was positive by ELISA and RIBA but negative by RT PCR, and one was positive only by RT PCR. Of two infected control patients, one was positive by all three tests and one who was later found to have been in the early stage of infection was positive only by RT PCR. Follow-up of infected patients showed persistence of viraemia in 14/15 (93%). Evidence of infection with different types of HCV was shown by the lack of amplification by RT PCR by primers with mismatching bases with HCV types 2 and 3. It is concluded that in our renal transplant patients, chronic HCV infection is usually associated with liver dysfunction and persistent infection is common.

Adult↗

Focal pancreatic infarction in pheochromocytoma.

A 21-year-old man presenting with jaundice and hypertension was found to have an extraadrenal pheochromocytoma. Cholangiography demonstrated a cavity in the head of the pancreas that was in communication with both the pancreatic and common bile ducts. Hemorrhage from the cavity led to the patient's death and postmortem examination revealed focal infarction of the pancreatic head. This case adds hemobilia, obstructive jaundice, and focal pancreatic infarction to the list of bizarre remote manifestations of pheochromocytoma.

Adrenal Gland Neoplasms↗

Neoterminal ileal blood flow after ileocolonic resection for Crohn's disease.

Endoscopic laser Doppler flowmetry was used to measure neoterminal ileal blood flow in 16 patients who had undergone ileocolonic resection for Crohn's disease and had since remained clinically and biochemically free of disease, and eight control patients who had undergone similar surgery for colonic carcinoma. Four patients with clinically active Crohn's disease of the terminal ileum were also studied. Neoterminal ileal recurrence in those with inactive Crohn's disease was graded endoscopically. The median and minimum of five local blood flow measurements performed in each patient were inversely correlated with the endoscopic recurrence grade (r = -0.52, p = 0.04 and r = -0.63, p = 0.01 respectively). Relative to the control group, median blood flow was non-significantly lower in the inactive Crohn's disease group as a whole (p > 0.05) but was significantly reduced in patients with active disease (p = 0.02). A progressive reduction in tissue perfusion may accompany recurrence of Crohn's disease while at a subclinical stage.

Adult↗

Gastrointestinal damage associated with the use of nonsteroidal antiinflammatory drugs.

BACKGROUND: Long-term use of nonsteroidal antiinflammatory drugs (NSAIDs) may lead to inflammation of the small intestine associated with occult blood and protein loss. The aim of this study was to investigate the prevalence and structural correlates of this enteropathy. METHODS: We examined the stomach, duodenum, and small intestine of 713 patients post mortem. Of these patients, 249 had had NSAIDs prescribed during the six months before death and 464 patients had not. All visible small intestinal lesions were removed for histologic examination, and specific etiologic factors were sought. The prevalence of nonspecific small-intestinal ulcers and ulcers of the stomach and duodenum was compared in the two groups of patients. RESULTS: Nonspecific small-intestinal ulceration was found in 21 (8.4 percent) of the users of NSAIDs and 3 (0.6 percent) of the nonusers (difference, 7.8 percent; 95 percent confidence interval, 5.0 to 10.6 percent; P less than 0.001). Three patients who were long-term users of NSAIDs were found to have died of perforated nonspecific small-intestinal ulcers. Ulcers of the stomach or duodenum were found in 54 (21.7 percent) of the patients who used these drugs and 57 (12.3 percent) of those who had not (difference, 9.4 percent; 95 percent confidence interval, 3.9 to 15.1 percent; P less than 0.001). CONCLUSIONS: Patients who take NSAIDs have an increased risk of nonspecific ulceration of the small-intestinal mucosa. These ulcers are less common than ulcers of the stomach or duodenum, but can lead to life-threatening complications.

Anti-Inflammatory Agents, Non-Steroidal↗

Randomised comparison of percutaneous endoscopic gastrostomy and nasogastric tube feeding in patients with persisting neurological dysphagia.

OBJECTIVE: To compare percutaneous endoscopic gastrostomy and nasogastric tube feeding in patients with persisting neurological dysphagia. DESIGN: Randomised 28 day study of inpatients requiring long term enteral nutrition. SETTING: Three Glasgow teaching hospitals. SUBJECTS: 40 patients with dysphagia for at least four weeks secondary to neurological disorders: 20 patients (10 women) were randomised to nasogastric feeding and 20 (eight women) to endoscopic gastrostomy. MAIN OUTCOME MEASURES: Treatment failure (blocked or displaced tubes on three or more occasions or refusal to continue treatment); duration of feeding; intake of liquid diets; complications; nutritional status at end of trial. RESULTS: One patient in each group died before starting feeding. Treatment failure occurred in 18 of the 19 nasogastric patients and in none of the gastrostomy group. The mean (SE) duration of feeding for the nasogastric group was 5.2 (1.5) days. No complications occurred in the nasogastric group but three (16%) of the gastrostomy group developed minor problems (aspiration pneumonia (two patients) wound infection (one)). Gastrostomy patients received a significantly greater proportion of their prescribed feed (93% (2%)) compared with the nasogastric group, (55% (4%); p less than 0.001) and also gained significantly more weight after seven days of feeding (1.4 (0.5) kg v 0.6 (0.1) kg; p less than 0.05). Analyses at days 14, 21, and 28 were not possible due to the small numbers remaining in the nasogastric group. CONCLUSION: Percutaneous endoscopic gastrostomy tube feeding is a safe and effective method of providing long term enteral nutrition to patients with neurological dysphagia and offers important advantages over nasogastric tube feeding.

Aged↗

Mucosal capillary thrombi in rectal biopsies.

We studied the initial rectal biopsy from 46 patients in whom subsequent follow-up established the diagnosis of either self-limited colitis or inflammatory bowel disease. An additional 12 non-inflamed rectal biopsies were also studied. There was between 2 and 8 years of follow-up in each of these cases. Staining for fibrin (MSB, fibrinogen), platelets (factor XIIIA, Y2/51), and capillary basement membrane (reticulin, collagen 4) was performed to identify thrombotic material within capillaries. Mucosal capillary thrombi were best identified by staining for factor XIIIA; thrombi were observed in 8/13 cases of ulcerative colitis, 4/10 cases of Crohn's disease, 1/3 cases of unspecified inflammatory bowel disease and 5/20 cases of self-limited colitis. The presence of capillary thrombi was not related to the severity of inflammation, but none of the control biopsies showed capillary thrombi. Their presence seems of little diagnostic value in distinguishing inflammatory bowel disease from self-limited colitis. The pathogenetic significance of these mucosal capillary thrombi is uncertain.

Adult↗

The spectrum of chronic liver disease in renal transplant recipients.

Chronic liver disease has been reported to be an important cause of late morbidity and mortality in renal transplant recipients. We have examined the prevalence and nature of chronic liver disease among 538 patients with functioning renal allografts managed at the Western Infirmary, Glasgow, between 1980 and 1989. Thirty-seven patients (7 per cent) satisfied biochemical criteria for chronic liver dysfunction. Liver biopsies were obtained from 24 of these, and autopsy tissue was available from three other patients. Chronic hepatitis of variable severity was present in 15 patients, haemosiderosis in 12 patients and nodular regenerative hyperplasia in five patients. Nineteen patients (51 per cent) had serological evidence of infection with the hepatitis C virus, and one of these developed chronic hepatitis B and D infection as well. Although a variety of chronic liver diseases occurred in our transplant population, the frequency of serious sequelae from liver dysfunction was much lower than that reported from transplant centres in other countries.

Chronic Disease↗

Percutaneous endoscopic gastrostomy tube feeding may improve outcome of late rehabilitation following stroke.

We describe three stroke patients with prolonged swallowing difficulty whose rehabilitation had been unsuccessful due to recurrent aspiration pneumonia and/or nasogastric tube dislodgement. Percutaneous endoscopic gastrostomy tube feeding, initiated 4-6 months following the onset of stroke, was associated with nutritional improvement, marked functional recovery and eventual discharge from hospital. This form of nutritional support may find an important role in the rehabilitation of stroke patients with persisting difficulty with swallowing.

Cerebrovascular Disorders↗

Changes in phenotypically distinct mucosal macrophage populations may be a prerequisite for the development of inflammatory bowel disease.

Previous studies have demonstrated the presence of much more marked macrophage heterogeneity in colonic mucosa affected by the idiopathic inflammatory bowel diseases (ulcerative colitis and Crohn's disease) than in normal mucosa. This study examines the morphology, distribution and phenotypic expression of mucosal macrophage-like cells in biopsies from patients with idiopathic inflammatory bowel disease in comparison with disease control samples from patients with colonic infection or ischaemia. Approximately 80% of macrophage-like cells in histologically normal mucosa co-express the antigens recognized by the monoclonal antibodies RFD1 (an interdigitating cell marker) and RFD7 (a marker for mature tissue macrophages). In idiopathic inflammatory bowel disease, the normal colonic macrophage population is partly replaced by cells staining positively with RFD7 alone, and, to a lesser extent, with RFD1+ dendritic cells. Sections from patients with infections and ischaemia exhibited epithelial HLA-DR positivity and infiltration of the lamina propria by a more heterogeneous population of macrophages than that seen in histologically normal mucosa. However, the displacement of the normal colonic macrophage phenotype by RFD7+ tissue macrophages occurred to a significantly greater extent in idiopathic inflammatory bowel disease than in disease control mucosa. A pathognomonic feature of the ulcerative colitis and Crohn's colitis sections was the clustering of RFD9+ epithelioid cells at the bases of disrupted crypts and adjacent to areas of mucosal damage. It is concluded that a degree of macrophage heterogeneity and macrophage infiltration can occur as a non-specific response to colonic mucosal damage. The distinctive feature of idiopathic inflammatory bowel disease mucosa is the almost complete replacement of the normal colonic mucosal macrophage population by tissue macrophages and epithelioid cells, and this phenomenon may be important in promoting the development of a chronic inflammatory state.

Adolescent↗

Prevalence of proximal faecal stasis in active ulcerative colitis.

Proximal faecal stasis may occur when faecal matter accumulates in the uninflamed colon above an area of active ulcerative colitis. This phenomenon is thought to be the cause of symptoms in some patients with distal disease. It is not known, however, how often patients with active distal colitis exhibit slow colonic transit. Fifty two consecutive patients with active ulcerative colitis each ingested 10 radio-opaque markers nightly for 14 days. Minimum colonic transit times were derived from counts of retained markers shown by plain abdominal radiography on the 15th day. The transit times for each patient were related to their disease extent and bowel frequency. Four patients had colonic transit times greater than one week and two others had evidence of relative stasis. The results indicate that approximately 10% of attacks of distal colitis are associated with faecal stasis.

Adult↗

Enhanced gastric mucosal haemostasis after upper gastrointestinal haemorrhage.

An endoscopic technique for the measurement of gastric mucosal bleeding time has been developed to study gastric haemostasis in patients with acute upper gastrointestinal haemorrhage. The relation of gastric mucosal bleeding time to skin bleeding time and nonsterodial anti-inflammatory drug usage was examined in 61 control patients and in 47 patients presenting with bleeding peptic ulcers or erosions. Gastric mucosal bleeding time was shorter in patients with haemorrhage (median 2 minutes, range 0-5 minutes) than in the control group (median 4 minutes, range 2-8 minutes) (p less than 0.001). Skin bleeding times were similar in the two groups (medians 4 minutes in patients with haemorrhage and 4.5 minutes in controls). In 21 patients with haemorrhage who were taking non-steroidal anti-inflammatory drugs, the median gastric mucosal bleeding time (2.5 minutes, range 1.0-5.0 minutes) was similar to that in 26 patients with haemorrhage not associated with these drugs (2.0 minutes, range 0.0-5.0 minutes). These results show that gastric mucosal haemostasis is accelerated in response to haemorrhage in the upper gastrointestinal tract, even in patients taking nonsteroidal anti-inflammatory drugs. This enhanced gastric haemostasis probably reflects a local protective response to minimise blood loss from the bleeding lesion.

Acute Disease↗

Immunohistological studies of surface antigen on colonic lymphoid cells in normal and inflamed mucosa. Comparison of follicular and lamina propria lymphocytes.

Mucosal samples from 16 patients with idiopathic inflammatory bowel disease were examined immunohistologically using several monoclonal antibody combinations, and the results were compared with those obtained in other colonic inflammatory disorders and in normal mucosa. Within and around lymphoid follicles, most T cells expressed the restricted common leucocyte antigen (CD45R, displayed by unprimed T cells). Conversely, most lamina propria T cells were negative for CD45R but stained positively with UCHL1 (a monoclonal antibody recognizing an antigen displayed by primed T lymphocytes). The proportions of T-lymphocyte subpopulations in normal and inflamed mucosa were similar, except that CD6-negative, CD7-positive cells were significantly more frequent in inflammatory bowel disease. A characteristic feature of ulcerative colitis and Crohn's colitis was marked infiltration by CD45R+ lymphoid cells that did not coexpress T- or B-cell surface antigens; some stained positively with plasma cell reagents, suggesting that they may be activated B cells. The observations in the colitis sections are consistent with the interpretation that T and B cells alter their surface antigen expression as they emerge from follicles and enter the inflamed lamina propria.

Antibodies, Monoclonal↗

Enprostil inhibits post-prandial gastrin release: a dose-response study.

In a double-blind placebo-controlled study in nine healthy volunteers, the effects of single doses of oral enprostil (8.75, 17.5, 35 and 70 micrograms), taken before a standard breakfast, were assessed on the post-prandial release of gastrin into the plasma. All doses of enprostil caused a significant dose-related decrease in median post-prandial plasma gastrin concentration (range from -29 to -44%). In the same subjects, two doses of 25 mg indomethacin caused a significant (38%) increase in median post-prandial plasma gastrin concentration.

Adult↗